JP7494030B2 - Process cartridge and electrophotographic apparatus - Google Patents

Description

The present invention relates to a process cartridge and an electrophotographic device.

In recent years, there has been a demand for smaller electrophotographic devices and an increase in the number of pages that can be printed in the electrophotographic process. In response to this demand, there is a demand for further reductions in toner consumption. In order to reduce toner consumption, there is a demand for a reduction in fog, which occurs when toner develops in non-image areas.

Japanese Patent Application Laid-Open No. 2003-233633 discloses a toner having improved developability and durability by adhering inorganic fine particles composed of phosphate anions and zirconium ions to the toner surface.
Japanese Patent Application Laid-Open No. 2003-233633 discloses a technique in which a siloxane-modified resin having a siloxane structure in the molecular chain is incorporated into the surface layer of an electrophotographic photoreceptor that comes into contact with various members.

JP 2001-209207 A JP 2007-199688 A

According to the inventors' investigations, the process cartridges described in Patent Documents 1 and 2 were improved in terms of reducing fogging that was visually confirmed on the image. However, it became clear that further reduction in fogging was desired in terms of reducing toner consumption.

Therefore, an object of the present invention is to provide a process cartridge and an electrophotographic device that reduce fogging in order to reduce toner consumption.

The above object can be achieved by the present invention described below.
That is, the process cartridge according to the present invention is a process cartridge having a developing means containing a toner and an electrophotographic photosensitive member, the process cartridge is configured to be detachably mounted in a main body of an electrophotographic apparatus, the toner is a toner having toner particles, the toner particles contain a titanium phosphate compound on at least a part of the surface thereof ,
the surface layer of the electrophotographic photoreceptor contains a polycarbonate resin containing a siloxane moiety or a polyester resin containing a siloxane moiety , the content of the polycarbonate resin containing a siloxane moiety or the polyester resin containing a siloxane moiety in the surface layer is from 0.1% by mass to 10% by mass, based on the total mass of the components constituting the surface layer, the polycarbonate resin containing a siloxane moiety is a resin that contains a structural unit represented by the following formula (PC) in an amount of from 60% by mass to 94% by mass, based on the total mass of the polycarbonate resin containing a siloxane moiety, and the polyester resin containing a siloxane moiety is a resin that contains a structural unit represented by the following formula (E) in an amount of from 60% by mass to 94% by mass, based on the total mass of the polyester resin containing a siloxane moiety .

Further, an electrophotographic apparatus according to the present invention is an electrophotographic apparatus having the above-mentioned process cartridge.
Further, an electrophotographic apparatus according to the present invention is an electrophotographic apparatus having a developing means containing a toner, and an electrophotographic photosensitive member, the toner being a toner having toner particles, the toner particles containing a titanium phosphate compound on at least a part of their surfaces , the surface layer of the electrophotographic photosensitive member containing a polycarbonate resin containing a siloxane moiety or a polyester resin containing a siloxane moiety , the content of the polycarbonate resin containing a siloxane moiety or the polyester resin containing a siloxane moiety in the surface layer being 0.1% by mass or more and 10% by mass or less with respect to the total mass of the components of the surface layer,
The polycarbonate resin containing a siloxane moiety is a resin containing a structural unit represented by the following formula (PC) in an amount of 60 mass % or more and 94 mass % or less, based on the total mass of the polycarbonate resin containing a siloxane moiety, and the polyester resin containing a siloxane moiety is a resin containing a structural unit represented by the following formula (E) in an amount of 60 mass % or more and 94 mass % or less, based on the total mass of the polyester resin containing a siloxane moiety.

According to the present invention, it is possible to provide a process cartridge and an electrophotographic device that reduce fogging in order to reduce toner consumption.

FIG. 1 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus having a process cartridge equipped with an electrophotographic photosensitive member.

The present invention will be described in detail below with reference to preferred embodiments.
In order to solve the above problems, the process cartridge and electrophotographic device of the present invention are characterized in that they have a configuration in which a toner having a polyvalent acid metal salt on at least a portion of the surface of the toner particles is combined with an electrophotographic photoreceptor containing a resin including a siloxane moiety in a surface layer.

The present inventors speculate as follows about the mechanism by which fog is reduced by combining a toner that satisfies the above characteristics with an electrophotographic photoreceptor.
In the electrophotographic process, an image is generally formed by forming a toner image on an electrophotographic photosensitive member and transferring the toner image onto an intermediate transfer member or paper.
A toner having a polyvalent acid metal salt on at least a part of the surface of a toner particle is easily negatively charged by the polarization of the polyvalent acid metal salt, and has excellent charging properties. In addition, the polyvalent acid metal salt has an appropriate resistance value, so that the charge is easily transferred. A negative charge is supplied to the polyvalent acid metal salt on the surface of the toner particle from a resin containing a siloxane moiety contained in the surface layer of the electrophotographic photoreceptor. This is considered to be because the polyvalent acid metal salt on the surface of the toner particle comes into contact with the resin containing a siloxane moiety in the surface layer of the electrophotographic photoreceptor, and charge is exchanged due to the electrification series between the constituent materials. Therefore, it is speculated that when a toner image is formed on the electrophotographic photoreceptor, a negative charge is supplied from the electrophotographic photoreceptor to the toner, improving the charging uniformity of the toner and reducing fogging.

[toner]
The toner in the present invention is a toner having toner particles, and is characterized in that the toner particles have a polyvalent acid metal salt on at least a portion of the surface thereof.
The polyvalent acid metal salt is composed of a combination of a polyvalent acid and a metal element.

The polyvalent acid may be any acid having a valence of two or more. Specific examples include the following acids. Inorganic acids include phosphoric acid, carbonic acid, and sulfuric acid. Organic acids include dicarboxylic acids and tricarboxylic acids. Specifically, dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, and terephthalic acid. Tricarboxylic acids include citric acid, aconitic acid, and trimellitic acid.
Among the polyvalent acids, it is preferable to contain at least one acid selected from phosphoric acid, carbonic acid, and sulfuric acid, because the metal element and the polyvalent acid react strongly and the polyvalent acid metal salt is less likely to absorb moisture.Moreover, it is preferable that the polyvalent acid contains phosphoric acid.

The metal element constituting the polyvalent acid metal salt preferably contains at least one metal element selected from the metal elements included in Groups 3 to 13. The salt constituted by a metal element included in Groups 3 to 13 and a polyvalent acid has low hygroscopicity, and therefore can stably obtain the effect of reducing fogging even in a high humidity environment.
Specific examples of metal elements include titanium, zirconium, aluminum, zinc, indium, hafnium, iron, copper, and silver. Among them, metals that can have a valence of three or more are preferred. More specifically, titanium, zirconium, and aluminum are more preferred, and titanium is even more preferred.

Examples of polyvalent acid metal salts are preferably metal phosphates, metal sulfates, metal carbonates, and metal oxalates. Examples of metal phosphates include titanium phosphate compounds, zirconium phosphate compounds, aluminum phosphate compounds, and copper phosphate compounds. Examples of metal sulfates include titanium sulfate compounds, zirconium sulfate compounds, and aluminum sulfate compounds. Examples of metal carbonates include titanium carbonate compounds, zirconium carbonate compounds, and aluminum carbonate compounds. Examples of metal oxalates include titanium oxalates. Among these, metal phosphates are preferred because they have high strength due to the phosphate ions bridging between metals, and have excellent charge build-up properties due to the presence of ionic bonds within the molecules, and titanium phosphate compounds are even more preferred.

There are no particular limitations on the method for producing the polyvalent acid metal salt, and any conventionally known method can be used. A preferred method is to obtain the polyvalent acid metal salt by reacting a metal compound containing a metal element with a polyvalent acid ion in an aqueous medium. Any conventionally known metal compound can be used without particular limitations as long as it is a metal compound that gives a polyvalent acid metal salt upon reaction with a polyvalent acid ion, and examples of such metal compounds include metal chelates and metal alkoxides.

Metal chelates include titanium lactate, titanium tetraacetylacetonate, titanium lactate ammonium salt, titanium triethanolamine, zirconium lactate, zirconium lactate ammonium salt, aluminum lactate, aluminum trisacetylacetonate, and copper lactate. Metal alkoxides include titanium tetraisopropoxide, titanium ethoxide, zirconium tetraisopropoxide, and aluminum trisisopropoxide. Among these, metal chelates are preferred because the reaction is easy to control and they react quantitatively with polyvalent acid ions. Furthermore, lactate chelates such as titanium lactate and zirconium lactate are even more preferred from the viewpoint of solubility in aqueous media.

When a polyvalent acid metal salt is obtained by the above-mentioned preparation method, the polyvalent acid ion can be the ion of the above-mentioned polyvalent acid. When added to the aqueous medium, the polyvalent acid itself can be added, or a water-soluble polyvalent acid metal salt can be added to the aqueous medium and dissociated in the aqueous medium.

The number-average particle size of the polyvalent acid metal salt is preferably 1 nm or more and 400 nm or less, more preferably 1 nm or more and 200 nm or less, and even more preferably 1 nm or more and 60 nm or less.

By setting the number-average particle size of the polyvalent metal salt within the above range, contamination of components caused by the polyvalent metal salt migrating from the toner to the photoreceptor surface or other components can be suppressed. This makes it easier to maintain the negative chargeability of the toner surface and the positive chargeability of the photoreceptor surface. This makes it easier to achieve the effect of reducing fogging.

Methods for adjusting the number-average particle size of the polyvalent acid metal salt to the above range include the amount of polyvalent acid and the compound containing a metal element added, which are the raw material for the particles, the pH during the reaction, and the temperature during the reaction.

When a polyvalent acid is reacted with a compound containing a metal element in a dispersion of toner base particles and the resulting reaction product is attached to the surface of the toner base particles to obtain toner particles, it is preferable to use an organosilicon compound represented by formula (T-1) in combination.

By using an organosilicon compound in combination, the resulting reaction product adheres more firmly to the toner particles, and the surface is made hydrophobic, further improving environmental stability.

Specifically, the organosilicon compound represented by formula (T-1) is hydrolyzed in advance or in a dispersion of toner mother particles. The obtained hydrolyzate of the organosilicon compound is then condensed to form a condensate. The condensate migrates to the surface of the toner particles. Since the condensate has viscosity, it is possible to make the reactant between the polyvalent acid and the compound containing a metal element adhere to the surface of the toner particles, and to more firmly fix the reactant to the toner particles. In addition, the condensate also migrates to the surface of the reactant, making it hydrophobic and further improving environmental stability.
R _{a (n)} -Si-R _{b (4-n)} (T-1)
In formula (T-1), R _a represents a halogen atom, a hydroxy group or an alkoxy group, R _b represents an alkyl group, an alkenyl group, an aryl group, an acyl group or a methacryloxyalkyl group, and n represents an integer of 2 to 4. However, when a plurality of R _a and R _b are present, the plurality of R _a and the plurality of R _b may be the same or different.

As the organosilicon compound represented by formula (T-1), known organosilicon compounds can be used without any particular restrictions. Specific examples include the following bifunctional silane compounds in which n is 2, trifunctional silane compounds in which n is 3, and tetrafunctional silane compounds in which n is 4.

Examples of bifunctional silane compounds include dimethyldimethoxysilane and dimethyldiethoxysilane.

Examples of the trifunctional silane compound include a trifunctional silane compound having an alkyl group as R _b , a trifunctional silane compound having an alkenyl group as R _b , a trifunctional silane compound having an aryl group as R _b , and a trifunctional silane compound having a methacryloxyalkyl group as R _b . Examples of the trifunctional silane compound having an alkyl group as R _b include methyltrimethoxysilane, methyltriethoxysilane, methyldiethoxymethoxysilane, methylethoxydimethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, and decyltriethoxysilane. Examples of trifunctional silane compounds having an alkenyl group as R _b include vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, and allyltriethoxysilane. Examples of trifunctional silane compounds having an aryl group as R _b include phenyltrimethoxysilane and phenyltriethoxysilane. Examples of trifunctional silane compounds having a methacryloxyalkyl group as _{R b} include γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyldiethoxymethoxysilane, and γ-methacryloxypropylethoxydimethoxysilane.

Tetrafunctional silane compounds include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane.

The content of the condensate of at least one organosilicon compound selected from the group consisting of organosilicon compounds represented by formula (T-1) in the toner particles is preferably 0.1% by mass or more and 20.0% by mass or less, and more preferably 0.5% by mass or more and 15.0% by mass or less.

The method for producing the toner base particles is not particularly limited, and known methods such as suspension polymerization, dissolution suspension, emulsion aggregation, and pulverization can be used.

When a reaction product between a polyvalent acid and a compound containing a metal element is present on the surface of the toner particles, if the toner base particles are produced in an aqueous medium, they may be used as is as a dispersion of the toner base particles. In addition, after washing, filtering, and drying, they may be redispersed in an aqueous medium to form a dispersion of the toner base particles.

On the other hand, when the toner base particles are produced by a dry method, they may be dispersed in an aqueous medium by a known method to prepare a dispersion liquid of the toner base particles. In order to disperse the toner base particles in the aqueous medium, it is preferable that the aqueous medium contains a dispersion stabilizer.

A specific example of the production of toner base particles using the suspension polymerization method will be described below.
First, a polymerizable monomer capable of producing a binder resin and, if necessary, various additives are mixed, and the materials are dissolved or dispersed using a disperser to prepare a polymerizable monomer composition.
The various additives include colorants, waxes, charge control agents, polymerization initiators, and chain transfer agents.
The dispersing machine may be a homogenizer, a ball mill, a colloid mill, or an ultrasonic dispersing machine.

Next, the polymerizable monomer composition is poured into an aqueous medium containing poorly water-soluble inorganic particles, and droplets of the polymerizable monomer composition are prepared using a high-speed disperser such as a high-speed stirrer or ultrasonic disperser (granulation process).

Thereafter, the polymerizable monomer in the droplets is polymerized to obtain toner base particles (polymerization step).
The polymerization initiator may be mixed when the polymerizable monomer composition is prepared, or may be mixed into the polymerizable monomer composition immediately before forming droplets in the aqueous medium.
Alternatively, the compound may be added in a state dissolved in the polymerizable monomer or in another solvent, as required, during or after the granulation of the droplets, that is, immediately before the start of the polymerization reaction.

After the polymerizable monomer is polymerized to obtain resin particles, a solvent removal process may be performed as necessary to obtain a dispersion of toner base particles.

Examples of the binder resin include the following resins or polymers.
Specific examples of the resin include vinyl resins, polyester resins, polyamide resins, furan resins, epoxy resins, xylene resins, and silicone resins. Among these, vinyl resins are preferred. Examples of the vinyl resin include polymers of the following monomers or copolymers thereof. Styrenic monomers such as styrene and α-methylstyrene. Unsaturated carboxylic acid esters such as methyl acrylate, butyl acrylate, methyl methacrylate, 2-hydroxyethyl methacrylate, t-butyl methacrylate, and 2-ethylhexyl methacrylate. Unsaturated carboxylic acids such as acrylic acid and methacrylic acid. Unsaturated dicarboxylic acids such as maleic acid. Unsaturated dicarboxylic anhydrides such as maleic anhydride. Nitrile vinyl monomers such as acrylonitrile. Halogen-containing vinyl monomers such as vinyl chloride. Nitro vinyl monomers such as nitrostyrene. Among these, copolymers using a styrene monomer and an unsaturated carboxylic acid ester as a monomer are preferred.

As the colorant, the following black pigment, yellow pigment, magenta pigment, and cyan pigment are used.
Black pigments include carbon black.

Yellow pigments include monoazo compounds, disazo compounds, condensed azo compounds, isoindolinone compounds, isoindoline compounds, benzimidazolone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specific examples include C.I. Pigment Yellow 74, 93, 95, 109, 111, 128, 155, 174, 180, and 185.

Examples of magenta pigments include monoazo compounds, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specific examples include C.I. Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, 238, 254, 269, and C.I. Pigment Violet 19.

Cyan pigments include copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds. Specific examples include C.I. Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, and 66.

In addition to the pigment, various dyes conventionally known as colorants may be used in combination.
The content of the colorant is preferably 1.0 part by mass or more and 20.0 parts by mass or less with respect to 100 parts by mass of the binder resin.

The toner can also be made magnetic by adding a magnetic material. In this case, the magnetic material can also serve as a colorant.

Magnetic materials include iron oxides such as magnetite, hematite, and ferrite; metals such as iron, cobalt, and nickel, or alloys and mixtures of these metals with metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, and vanadium.

Examples of waxes include monohydric alcohol and aliphatic monocarboxylic acid esters such as behenyl behenate, stearyl stearate, and palmityl palmitate, or esters of monohydric carboxylic acids and aliphatic monoalcohols; dihydric alcohol and aliphatic monocarboxylic acid esters such as dibehenyl sebacate and hexanediol dibehenate, or esters of dihydric carboxylic acids and aliphatic monoalcohols; trihydric alcohol and aliphatic monocarboxylic acid esters such as glycerin tribehenate, or esters of trihydric carboxylic acids and aliphatic monoalcohols; tetrahydric alcohol and aliphatic monocarboxylic acid esters such as pentaerythritol tetrastearate and pentaerythritol tetrapalmitate, or esters of tetrahydric carboxylic acids and aliphatic monoalcohols: dipentaerythritol helixate, Examples of such waxes include hexahydric alcohols and aliphatic monocarboxylic acid esters, such as hexastearate and dipentaerythritol hexapalmitate, or esters of hexahydric carboxylic acids and aliphatic monoalcohols; polyhydric alcohols and aliphatic monocarboxylic acid esters, such as polyglycerin behenate, or esters of polyhydric carboxylic acids and aliphatic monoalcohols; natural ester waxes, such as carnauba wax and rice wax; petroleum waxes and derivatives thereof, such as paraffin wax, microcrystalline wax, and petrolatum; hydrocarbon waxes produced by the Fischer-Tropsch process and derivatives thereof; polyolefin waxes and derivatives thereof, such as polyethylene wax and polypropylene wax; higher aliphatic alcohols; fatty acids, such as stearic acid and palmitic acid; and acid amide waxes.

The wax content is preferably 0.5 parts by mass or more and 20.0 parts by mass or less per 100 parts by mass of the binder resin.

Various organic or inorganic particles may be added to the toner particles to the extent that the properties or effects of the toner are not impaired. Examples of organic or inorganic particles include flowability imparting agents such as silica, alumina, titanium oxide, carbon black, and carbon fluoride; abrasives such as metal oxides (strontium titanate, cerium oxide, alumina, magnesium oxide, and chromium oxide), nitrides (silicon nitride), carbides (silicon carbide), and metal salts (calcium sulfate, barium sulfate, and calcium carbonate); lubricants such as fluorine-based resin particles (vinylidene fluoride, polytetrafluoroethylene), and fatty acid metal salts (zinc stearate, calcium stearate); and charge control particles such as metal oxides (tin oxide, titanium oxide, zinc oxide, silica, and alumina) and carbon black.

The organic particles and/or inorganic particles may be hydrophobized. Examples of treatment agents for hydrophobizing the organic particles and/or inorganic particles include unmodified silicone varnish, various modified silicone varnishes, unmodified silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organosilicon compounds, and organotitanium compounds. These treatment agents may be used alone or in combination.

<Cross-sectional structure of toner particle>
A preferred form of a cross section of a toner particle constituting the toner of the present invention observed with a transmission electron microscope will be described below.

By comparing the cross section of the toner particle observed under a transmission electron microscope with the EDX mapping image of the constituent elements of the cross section of the toner particle obtained by analyzing using energy dispersive X-ray spectroscopy (EDX), it can be confirmed that the organosilicon polymer forms convex portions at positions corresponding to the surface of the toner mother particle. In the toner particles constituting the toner of the present invention, when the height of the convex portion is defined as the convex height H, it is preferable that the convex height H is 30 nm or more and 300 nm or less. The method for calculating the convex height H will be described later.

In the toner of the present invention, when the metal element contained in the polyvalent acid metal salt is designated as metal element M and the ratio of metal element M in the ratio of constituent elements on the surface of the toner particles obtained from the spectrum obtained by X-ray photoelectron spectroscopy of the toner particles is designated as M1 (atm %), it is preferable that M1 is 1.0 (atm %) or more and 10.0 (atm %) or less.

Also, toner (a) is obtained by dispersing 1 g of toner in a mixed aqueous solution consisting of 31 g of a 61.5% sucrose aqueous solution and 6 g of a 10% aqueous solution of a neutral detergent for cleaning precision measuring instruments, which is composed of a nonionic surfactant and an anionic surfactant, and shaking the mixture 300 times per minute using a shaker (a). When the ratio of metal element M in the ratio of constituent elements on the surface of the toner particles obtained from the spectrum obtained by X-ray photoelectron spectroscopy of toner (a) is M2 (atm %), it is preferable that both M1 and M2 are 1.0 (atm %) or more and 10.0 (atm %) or less, and M1 and M2 satisfy the following formula (ME-1).
0.90≦M2/M1 (ME-1)

Treatment (a) can remove polyvalent metal salts that are weakly attached to the surface of the toner particles. Specifically, polyvalent metal salts that are attached to the toner base particles by a dry method are easily removed by treatment (a). Therefore, treatment (a) makes it possible to evaluate the adhesion state of the polyvalent metal salts present on the surface of the toner particles, and the smaller the change in each parameter due to treatment (a), the stronger the adhesion of the polyvalent metal salts to the toner base particles.

M1 and M2 represent the state of coating of the surface of the toner particles with the polyvalent acid metal salt before and after the treatment (a). The state of coating of the surface of the toner particles with the polyvalent acid metal salt contributes to the chargeability and charge mobility of the toner.

When M1 and M2 are both 1.0 (atm%) or more and 10.0 (atm%) or less, the toner has good negative chargeability and charge mobility, so charge transfer from the electrophotographic photoreceptor to the toner becomes smoother, making it easier to achieve the effect of reducing fogging. M1 and M2 are more preferably 1.0 (atm%) or more and 7.0 (atm%) or less, and even more preferably 1.5 (atm%) or more and 5.0 (atm%) or less.

The formula (ME-1) means the ratio of the polyvalent acid metal salt that does not peel off from the surface of the toner particles in the process (a) and remains. When M2/M1 is 0.90 or more, the polyvalent acid metal salt is strongly attached to the surface of the toner particles, and migration of the polyvalent acid metal salt from the toner to the surface of the photoreceptor is suppressed. Therefore, such a toner is excellent in durability, in which the negative chargeability of the surface of the toner particles and the positive chargeability of the surface of the photoreceptor are easily maintained, and fogging can be stably reduced even during long-term use. It is further preferable that M2/M1 is 0.95 or more.

<Method of forming convex portions containing organosilicon polymer>
There is no particular restriction on the method for forming the convex portions containing the organosilicon polymer of the toner particles, and any conventionally known method can be used.Specific examples include a method in which a compound shown in the section on organosilicon compounds is condensed in an aqueous medium in which the toner base particles are dispersed to form convex portions on the toner base particles, and a method in which convex portions containing an organosilicon polymer are attached to the toner base particles by mechanical external force in a dry or wet manner.

Among these, a method in which a compound shown in the section on organosilicon compounds is condensed in an aqueous medium in which toner base particles are dispersed to form convex portions on the toner base particles is preferred, as this makes it possible to firmly bond the toner base particles to the convex portions. Details are described below.

When forming convex portions on the toner base particles by the above method, it is preferable to include a step (step 1) of dispersing the toner base particles in an aqueous medium to obtain a toner base particle dispersion, and a step (step 2) of mixing an organosilicon compound (or its hydrolyzate) with the toner base particle dispersion and causing a condensation reaction of the organosilicon compound in the toner base particle dispersion to form convex portions containing an organosilicon polymer on the toner base particles.

In step 1, the toner base particle dispersion can be obtained by using the dispersion of toner base particles produced in an aqueous medium as is, or by adding dried toner base particles to an aqueous medium and dispersing them mechanically. When dispersing dried toner base particles in an aqueous medium, a dispersion aid may be used.

As the dispersion aid, known dispersion stabilizers and surfactants can be used. Specific examples of the dispersion stabilizer include inorganic dispersion stabilizers such as tricalcium phosphate, hydroxyapatite, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, and alumina, and organic dispersion stabilizers such as polyvinyl alcohol, gelatin, methyl cellulose, methylhydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, and starch. Examples of the surfactant include anionic surfactants such as alkyl sulfate ester salts, alkylbenzene sulfonates, and fatty acid salts, nonionic surfactants such as polyoxyethylene alkyl ethers and polyoxypropylene alkyl ethers, and cationic surfactants such as alkylamine salts and quaternary ammonium salts. Among these, it is preferable to include an inorganic dispersion stabilizer, and it is more preferable to include a dispersion stabilizer containing a phosphate such as tricalcium phosphate, hydroxyapatite, magnesium phosphate, zinc phosphate, or aluminum phosphate.

In step 2, the organosilicon compound may be added to the toner base particle dispersion liquid as it is, or may be added to the toner base particle dispersion liquid after hydrolysis. Among them, it is preferable to add it after hydrolysis, since the condensation reaction is easy to control and the amount of organosilicon compound remaining in the toner base particle dispersion liquid can be reduced. The hydrolysis is preferably carried out in an aqueous medium whose pH is adjusted using a known acid and base. It is known that the hydrolysis of an organosilicon compound is pH-dependent, and it is preferable to change the pH when carrying out the hydrolysis appropriately depending on the type of organosilicon compound. For example, when methyltriethoxysilane is used as the organosilicon compound, it is preferable that the pH of the aqueous medium is 2.0 or more and 6.0 or less.

Acids for adjusting the pH include inorganic acids such as hydrochloric acid, hydrobromic acid, hydroiodic acid, hypochlorous acid, chlorous acid, chloric acid, perchloric acid, hypobromous acid, bromous acid, bromic acid, perbromic acid, hypoiodous acid, iodous acid, iodic acid, periodic acid, sulfuric acid, nitric acid, phosphoric acid, and boric acid, and organic acids such as acetic acid, citric acid, formic acid, gluconic acid, lactic acid, oxalic acid, and tartaric acid.

Bases for adjusting the pH include alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, and lithium hydroxide, and their aqueous solutions; alkali metal carbonates such as potassium carbonate, sodium carbonate, and lithium carbonate, and their aqueous solutions; alkali metal sulfates such as potassium sulfate, sodium sulfate, and lithium sulfate, and their aqueous solutions; alkali metal phosphates such as potassium phosphate, sodium phosphate, and lithium phosphate, and their aqueous solutions; alkaline earth metal hydroxides such as calcium hydroxide and magnesium hydroxide, and their aqueous solutions; ammonia, amines such as triethylamine, etc.

The condensation reaction in step 2 is preferably controlled by adjusting the pH of the toner base particle dispersion. It is known that the condensation reaction of an organosilicon compound is pH-dependent, and the pH when the condensation reaction is carried out is preferably changed appropriately depending on the type of organosilicon compound. For example, when methyltriethoxysilane is used as the organosilicon compound, the pH of the aqueous medium is preferably 6.0 or more and 12.0 or less. By adjusting the pH, it is possible to control the convex height H and convex width W of the convex portion of the present invention, making it easier to obtain the effects of the present invention. As the acid and base for adjusting the pH, the acids and bases exemplified in the hydrolysis section can be used.

<Method of measuring weight average particle diameter (D4) and number average particle diameter (D1) of toner particles>
The weight average particle diameter (D4) and number average particle diameter (D1) of the toner particles are calculated as follows.
The measuring device used is a precision particle size distribution measuring device using the pore electrical resistance method, "Coulter Counter Multisizer 3" (registered trademark) (manufactured by Beckman Coulter, Inc.), equipped with a 100 μm aperture tube. The measurement conditions are set and the measurement data is analyzed using the accompanying dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter, Inc.). The measurement is performed using an effective measurement channel count of 25,000 channels.
The aqueous electrolyte solution used for the measurement is prepared by dissolving special grade sodium chloride in ion-exchanged water to a concentration of 1.0%, for example, "ISOTON II" (product name) (manufactured by Beckman Coulter, Inc.).

Before performing measurements and analysis, the dedicated software is set up as follows.
On the "Change standard measurement method (SOMME)" screen of the dedicated software, set the total count number in the control mode to 50,000 particles, the number of measurements to 1, and the Kd value to the value obtained using "Standard particles 10.0 μm" (product name) (manufactured by Beckman Coulter, Inc.).
Press the "Threshold/Noise Level Measurement Button" to automatically set the threshold and noise level. Also, set the current to 1,600 μA, the gain to 2, the electrolyte to ISOTON II, and check "Flush aperture tube after measurement."
In the "Pulse to particle size conversion setting" screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bins, and the particle size range is set to 2 μm to 60 μm.

The specific measurement method is as follows.
(1) 200.0 mL of the electrolyte solution is placed in a 250 mL round-bottom glass beaker for use with the Multisizer 3, which is then set on the sample stand. The stirrer rod is stirred counterclockwise at 24 rotations per second. Then, dirt and air bubbles are removed from inside the aperture tube using the "aperture tube flush" function of the dedicated software.
(2) 30.0 mL of the aqueous electrolyte solution is placed in a 100 mL flat-bottom glass beaker, and 0.3 mL of a dilution obtained by diluting "Contaminon N" (trade name) (a 10% aqueous solution of a neutral detergent for cleaning precision measuring instruments, pH 7, consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) three times by mass with ion-exchanged water is added thereto as a dispersant.
(3) Prepare an ultrasonic disperser "Ultrasonic Dispersion System Tetra150" (product name) (manufactured by Nikkaki Bios Co., Ltd.) that has two built-in oscillators with an oscillation frequency of 50 kHz and an electrical output of 120 W. Place 3.3 L of ion-exchanged water in the water tank of the ultrasonic disperser, and add 2.0 mL of Contaminon N to the water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height position of the beaker is adjusted so that the resonance state of the liquid surface of the electrolytic solution in the beaker is maximized.
(5) While the electrolyte solution in the beaker in (4) is irradiated with ultrasonic waves, 10 mg of toner particles are added little by little to the electrolyte solution and dispersed. Then, ultrasonic dispersion treatment is continued for another 60 seconds. During ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to be 10°C or higher and 40°C or lower.
(6) The electrolyte solution (5) in which the toner particles are dispersed is dropped into the round-bottom beaker (1) placed in the sample stand using a pipette to adjust the measurement concentration to 5%. Then, the measurement is continued until the number of particles measured reaches 50,000.
(7) The measurement data is analyzed using the dedicated software provided with the device to calculate the weight average particle diameter (D4) and number average particle diameter (D1). Note that when the dedicated software is set to graph/volume %, the "average diameter" on the "analysis/volume statistics (arithmetic mean)" screen is the weight average particle diameter (D4), and when the dedicated software is set to graph/number %, the "average diameter" on the "analysis/number statistics (arithmetic mean)" screen is the number average particle diameter (D1).

[Electrophotographic Photoreceptor]
In the present invention, the electrophotographic photoreceptor is characterized in that the surface layer contains a resin containing a siloxane moiety.
As a method for manufacturing an electrophotographic photoreceptor, a method of preparing the coating liquid for each layer described later, coating the layers in the desired order, and drying the liquid can be mentioned. In this case, as a method for coating the coating liquid, dip coating, spray coating, inkjet coating, roll coating, die coating, blade coating, curtain coating, wire bar coating, and ring coating can be mentioned. Among these, dip coating is preferable from the viewpoint of efficiency and productivity.

Each layer will be described below.
<Support>
In the present invention, the electrophotographic photoreceptor has a support. The support is preferably a conductive support having electrical conductivity. The shape of the support may be a cylinder, a belt, or a sheet. Of these, a cylindrical support is preferable. The surface of the support may be subjected to electrochemical treatment such as anodization, blasting, cutting, or the like.
The material of the support is preferably metal, resin or glass.
Examples of the metal include aluminum, iron, nickel, copper, gold, stainless steel, and alloys thereof. Among these, an aluminum support using aluminum is preferred.
Furthermore, the resin or glass may be made conductive by a process such as mixing with or coating with a conductive material.

<Conductive Layer>
A conductive layer may be provided on the support. By providing the conductive layer, scratches and irregularities on the surface of the support can be concealed and light reflection on the surface of the support can be controlled.
The conductive layer preferably contains conductive particles and a resin.

The conductive particles may be made of a material such as a metal oxide, a metal, or carbon black.
Examples of metal oxides include zinc oxide, aluminum oxide, indium oxide, silicon oxide, zirconium oxide, tin oxide, titanium oxide, magnesium oxide, antimony oxide, and bismuth oxide. Examples of metals include aluminum, nickel, iron, nichrome, copper, zinc, and silver.
Among these, it is preferable to use metal oxides as the conductive particles, and it is particularly preferable to use titanium oxide, tin oxide, or zinc oxide.
When a metal oxide is used as the conductive particles, the surface of the metal oxide may be treated with a material such as a silane coupling agent, or the metal oxide may be doped with an element such as phosphorus, aluminum, or niobium or an oxide thereof.
The conductive particles may have a laminated structure having a core particle and a coating layer that covers the core particle. The core particle may be titanium oxide, barium sulfate, or zinc oxide. The coating layer may be a metal oxide such as tin oxide or titanium oxide.
When a metal oxide is used as the conductive particles, the volume average particle size thereof is preferably 1 nm or more and 500 nm or less, and more preferably 3 nm or more and 400 nm or less.

Examples of the resin include polyester resin, polycarbonate resin, polyvinyl acetal resin, acrylic resin, silicone resin, epoxy resin, melamine resin, polyurethane resin, phenol resin, and alkyd resin.
The conductive layer may further contain a masking agent such as silicone oil, resin particles, or titanium oxide.

The average thickness of the conductive layer is preferably 1 μm or more and 50 μm or less, and particularly preferably 3 μm or more and 40 μm or less.

The conductive layer can be formed by preparing a conductive layer coating solution containing the above-mentioned materials and solvent, forming a coating film, and drying it. Examples of solvents used in the coating solution include alcohol-based solvents, sulfoxide-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents. Examples of dispersion methods for dispersing conductive particles in the conductive layer coating solution include methods using a paint shaker, sand mill, ball mill, and liquid collision type high-speed disperser.

<Undercoat layer>
An undercoat layer may be provided on the support or the conductive layer, which can improve adhesion between layers and provide a charge injection blocking function.
The undercoat layer preferably contains a resin. Alternatively, the undercoat layer may be formed as a cured film by polymerizing a composition containing a monomer having a polymerizable functional group.

Examples of resins include polyester resin, polycarbonate resin, polyvinyl acetal resin, acrylic resin, epoxy resin, melamine resin, polyurethane resin, phenol resin, polyvinylphenol resin, alkyd resin, polyvinyl alcohol resin, polyethylene oxide resin, polypropylene oxide resin, polyamide resin, polyamic acid resin, polyimide resin, polyamideimide resin, and cellulose resin.

Polymerizable functional groups possessed by monomers having polymerizable functional groups include isocyanate groups, blocked isocyanate groups, methylol groups, alkylated methylol groups, epoxy groups, metal alkoxide groups, hydroxyl groups, amino groups, carboxyl groups, thiol groups, carboxylic anhydride groups, and carbon-carbon double bond groups.

The undercoat layer may further contain an electron transport material, a metal oxide, a metal, or a conductive polymer in order to improve electrical properties. Of these, it is preferable to use an electron transport material or a metal oxide.

Examples of electron transport substances include quinone compounds, imide compounds, benzimidazole compounds, cyclopentadienylidene compounds, fluorenone compounds, xanthone compounds, benzophenone compounds, cyanovinyl compounds, aryl halide compounds, silole compounds, and boron-containing compounds. An electron transport substance having a polymerizable functional group may be used as the electron transport substance, and the undercoat layer may be formed as a cured film by copolymerizing it with a monomer having a polymerizable functional group.

Metal oxides include indium tin oxide, tin oxide, indium oxide, titanium oxide, zinc oxide, aluminum oxide, and silicon dioxide. Metals include gold, silver, and aluminum.

The surface of the metal oxide may be treated with a material such as a silane coupling agent, or the metal oxide may be doped with an element such as phosphorus, aluminum, or niobium or an oxide thereof.
The undercoat layer may further contain an additive.

The average thickness of the undercoat layer is preferably 0.1 μm or more and 50 μm or less, more preferably 0.2 μm or more and 40 μm or less, and particularly preferably 0.3 μm or more and 30 μm or less.

The undercoat layer can be formed by preparing a coating solution for the undercoat layer containing the above-mentioned materials and solvent, forming a coating film, and drying and/or curing the film. Examples of solvents used in the coating solution include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents.

<Photosensitive layer>
The photosensitive layer of an electrophotographic photoreceptor is mainly classified into (1) a laminated type photosensitive layer and (2) a single-layer type photosensitive layer. (1) The laminated type photosensitive layer has a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material. (2) The single-layer type photosensitive layer has a photosensitive layer containing both a charge generation material and a charge transport material.

(1) Multi-Layer Photosensitive Layer The multi-layer photosensitive layer has a charge generating layer and a charge transport layer.

(1-1) Charge Generation Layer The charge generation layer preferably contains a charge generation material and a resin.

Examples of charge generating substances include azo pigments, perylene pigments, polycyclic quinone pigments, indigo pigments, and phthalocyanine pigments. Of these, azo pigments and phthalocyanine pigments are preferred. Of the phthalocyanine pigments, oxytitanium phthalocyanine pigments, chlorogallium phthalocyanine pigments, and hydroxygallium phthalocyanine pigments are preferred.

The content of the charge generating material in the charge generating layer is preferably 40% by weight or more and 85% by weight or less, and more preferably 60% by weight or more and 80% by weight or less, based on the total weight of the charge generating layer.

Examples of resins include polyester resin, polycarbonate resin, polyvinyl acetal resin, polyvinyl butyral resin, acrylic resin, silicone resin, epoxy resin, melamine resin, polyurethane resin, phenol resin, polyvinyl alcohol resin, cellulose resin, polystyrene resin, polyvinyl acetate resin, and polyvinyl chloride resin. Among these, polyvinyl butyral resin is more preferable.

The charge generating layer may further contain additives such as antioxidants and ultraviolet absorbers. Specific examples include hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, and benzophenone compounds.

The average thickness of the charge generating layer is preferably 0.1 μm or more and 1 μm or less, and more preferably 0.15 μm or more and 0.4 μm or less.

The charge generation layer can be formed by preparing a coating solution for the charge generation layer containing the above-mentioned materials and solvent, forming a coating film, and drying it. Examples of solvents used in the coating solution include alcohol-based solvents, sulfoxide-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents.

(1-2) Charge Transport Layer The charge transport layer preferably contains a charge transport material and a resin.

Examples of the charge transport material include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, benzidine compounds, triarylamine compounds, and resins having groups derived from these materials. Among these, triarylamine compounds and benzidine compounds are preferred.
The content of the charge transport material in the charge transport layer is preferably 25% by weight to 70% by weight, and more preferably 30% by weight to 55% by weight, based on the total weight of the charge transport layer.

Examples of the resin include polyester resin, polycarbonate resin, acrylic resin, and polystyrene resin. Among these, polycarbonate resin and polyester resin are preferable. As the polyester resin, polyarylate resin is particularly preferable.
The content ratio (mass ratio) of the charge transport material to the resin is preferably from 4:10 to 20:10, and more preferably from 5:10 to 12:10.

The charge transport layer may also contain additives such as antioxidants, UV absorbers, plasticizers, leveling agents, slippage agents, and abrasion resistance improvers. Specific examples include hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, siloxane-modified resins, silicone oils, fluororesin particles, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, and boron nitride particles.

The average thickness of the charge transport layer is preferably 5 μm or more and 50 μm or less, more preferably 8 μm or more and 40 μm or less, and particularly preferably 10 μm or more and 17 μm or less.

The charge transport layer can be formed by preparing a coating liquid for the charge transport layer containing the above-mentioned materials and solvent, forming a coating film, and drying it. Examples of the solvent used in the coating liquid include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents. Among these solvents, ether-based solvents or aromatic hydrocarbon-based solvents are preferred.

(2) Single-layer type photosensitive layer The single-layer type photosensitive layer can be formed by preparing a coating solution for the photosensitive layer containing a charge generating material, a charge transporting material, a resin and a solvent, forming a coating film, and drying it. The charge generating material, the charge transporting material and the resin are the same as the examples of materials in the above "(1) Multi-layer type photosensitive layer".

<Surface layer>
The surface layer in the present invention refers to a charge transport layer when the photosensitive layer is a laminated type photosensitive layer, and refers to a photosensitive layer when the photosensitive layer is a single-layer type photosensitive layer. Also, when a protective layer is provided on the photosensitive layer, the surface layer in the present invention refers to a protective layer.

The electrophotographic photoreceptor of the present invention is characterized in that the surface layer contains a resin containing a siloxane moiety.
The resin having a siloxane moiety in the present invention is a resin having a siloxane moiety in the structure constituting the resin. Therefore, when the surface layer is a photosensitive layer, the resin for the charge transport layer contains a resin having a siloxane moiety.

As the resin containing a siloxane moiety, any resin containing a siloxane moiety can be used. In particular, as the resin containing a siloxane moiety, a polycarbonate resin containing a siloxane moiety or a polyester resin containing a siloxane moiety is preferable.

式（Ａ）中のｎは、括弧内の構造の繰り返し数の平均値を示し、１０以上、１２０以下である。ｎは２０以上、８０以下であることが電子写真感光体の繰り返し使用時の耐久性の維持の観点で好ましい。

式（Ｂ）中のａ、ｂおよびｃは、それぞれ独立に括弧内の構造の繰り返し数の平均値を示し、ａおよびｂは１以上、１０以下であり、ｃは、２０以上、２００以下である。ａおよびｂは１以上、５以下であることが好ましく、ｃは、２０以上、８０以下であることが電子写真感光体の繰り返し使用時の耐久性の維持の観点で好ましい。

式（Ｃ）中のｄは、括弧内の構造の繰り返し数の平均値を示し、１０以上、１２０以下である。Ｚは炭素数３以下のアルキレン基を示す。ｄは２０以上、８０以下であることが電子写真感光体の繰り返し使用時の耐久性の維持の観点で好ましい。 The siloxane moiety contained in the polycarbonate resin containing a siloxane moiety or the polyester resin containing a siloxane moiety is preferably a structure represented by formula (A), a structure represented by formula (B), or a structure represented by formula (C).

In formula (A), n represents the average number of repetitions of the structure in parentheses, and is from 10 to 120. n is preferably from 20 to 80 from the viewpoint of maintaining durability during repeated use of the electrophotographic photoreceptor.

In formula (B), a, b, and c each independently represent an average value of the number of repetitions of the structure in parentheses, where a and b are 1 or more and 10 or less, and c is 20 or more and 200 or less. It is preferable that a and b are 1 or more and 5 or less, and c is 20 or more and 80 or less, from the viewpoint of maintaining durability during repeated use of the electrophotographic photoreceptor.

In formula (C), d represents the average number of repetitions of the structure in parentheses and is 10 to 120. Z represents an alkylene group having 3 or less carbon atoms. d is preferably 20 to 80 from the viewpoint of maintaining durability during repeated use of the electrophotographic photoreceptor.

式（Ｂ）で示される構造を有するシロキサン部位を含むポリカーボネート樹脂の具体例としては、式（Ｂ－ＰＣ）で示される構造単位を有する樹脂である。

式（Ｃ）で示される構造を有するシロキサン部位を含むポリカーボネート樹脂の具体例としては、式（Ｃ－ＰＣ）で示される構造単位を有する樹脂である。

The resin containing a siloxane moiety will be specifically described below.
A specific example of a polycarbonate resin containing a siloxane moiety having the structure represented by formula (A) is a resin having a structural unit represented by formula (A-PC).

A specific example of a polycarbonate resin containing a siloxane moiety having the structure represented by formula (B) is a resin having a structural unit represented by formula (B-PC).

A specific example of a polycarbonate resin containing a siloxane moiety having the structure represented by formula (C) is a resin having a structural unit represented by formula (C-PC).

式（ＰＣ）中、Ｒ^１～Ｒ^４は、それぞれ独立に水素原子、またはメチル基を示す。Ｙ^１は、置換基としてアルキル基、またはフェニル基を有してもよいメチレン基、シクロヘキシリデン基、酸素原子、または単結合を示す。 The polycarbonate resin containing a siloxane moiety has a structural unit represented by formula (A-PC) or formula (B-PC), or a structural unit represented by formula (C-PC) at its terminal, but may be a copolymer resin with other structural units. Examples of the other structural units include the structural unit represented by formula (PC).

In formula (PC), R ¹ to R ⁴ each independently represent a hydrogen atom or a methyl group, and ^{Y 1} represents a methylene group which may have an alkyl group or a phenyl group as a substituent, a cyclohexylidene group, an oxygen atom, or a single bond.

中でも、式（ＰＣ－１）、（ＰＣ－５）、（ＰＣ－７）、（ＰＣ－８）、（ＰＣ－９）で示される構造単位であることが好ましく、特に式（ＰＣ－７）で示される構造単位であることが好ましい。 Specific examples of the structural unit represented by formula (PC) are given below.

Among these, structural units represented by formulae (PC-1), (PC-5), (PC-7), (PC-8) and (PC-9) are preferred, and structural units represented by formula (PC-7) are particularly preferred.

The polycarbonate resin containing a siloxane moiety may be a polycarbonate resin that combines a structural unit represented by formula (A-PC) or formula (B-PC) with a structural unit represented by formula (PC).

When the polycarbonate resin containing siloxane moieties has a structural unit represented by formula (PC) in addition to the structural unit represented by formula (A-PC) or the structural unit represented by formula (B-PC), the total content of the structural unit represented by formula (A-PC) and the structural unit represented by formula (B-PC) is preferably 6% by mass or more and 40% by mass or less relative to the total mass of the polycarbonate resin containing siloxane moieties. Also, the content of the structural unit represented by formula (PC) is preferably 60% by mass or more and 94% by mass or less relative to the total mass of the polycarbonate resin containing siloxane moieties. More preferably, the total content of the structural unit represented by formula (A-PC) and the structural unit represented by formula (B-PC) is 10% by mass or more and 20% by mass or less relative to the total mass of the polycarbonate resin containing siloxane moieties, and the content of the structural unit represented by formula (PC) is 60% by mass or more and 90% by mass or less relative to the total mass of the polycarbonate resin containing siloxane moieties.

When a polycarbonate resin containing a siloxane moiety has a structural unit represented by formula (PC) in addition to the structural unit represented by formula (A-PC) or the structural unit represented by formula (B-PC), the polycarbonate resin containing a siloxane moiety is a copolymer containing the structural unit represented by formula (A-PC) or the structural unit represented by formula (B-PC) and the structural unit represented by formula (PC). The copolymerization form may be any of block copolymerization, random copolymerization, alternating copolymerization, etc.

The polycarbonate resin containing a siloxane moiety may be a resin having a structure represented by the formula (C-PC) at the end of a polycarbonate resin that combines multiple structures from structural units represented by the formula (PC).

When a polycarbonate resin containing a siloxane moiety has a structural unit represented by formula (C-PC) at the end of a polycarbonate resin containing a structure represented by formula (PC), the content of the structural unit represented by formula (C-PC) is preferably 0.5% by mass or more and 3% by mass or less relative to the total mass of the polycarbonate resin containing a siloxane moiety. It is further preferably 0.8% by mass or more and 2% by mass or less.

The weight average molecular weight of the polycarbonate resin containing siloxane moieties is preferably 30,000 or more and 200,000 or less. It is even more preferably 40,000 or more and 150,000 or less. The weight average molecular weight is a polystyrene-equivalent weight average molecular weight measured according to a conventional method, specifically, by the method described in JP-A-2007-79555.

The copolymerization ratio of the polycarbonate resin containing a siloxane moiety can be confirmed by a general method of converting the peak area ratio of hydrogen atoms (hydrogen atoms constituting the resin) in ¹ H-NMR measurement of the resin.

Tables 1 to 3 show examples of polycarbonate resins containing siloxane moieties according to the present invention.

Table 1 shows examples of polycarbonate resins containing structural units represented by formula (A-PC) and structural units represented by formula (PC). In Table 1, n indicates the value of n in formula (A-PC). (PC) indicates a specific example of the structural unit represented by formula (PC). (A-PC)/(PC) indicates the copolymerization ratio (mass ratio) of the structural unit represented by formula (A-PC) and the structural unit represented by formula (PC). Mw indicates the weight average molecular weight.

表２には、式（Ｂ－ＰＣ）で示される構造単位と式（ＰＣ）で示される構造単位を含むポリカーボネート樹脂を例示する。表２中、ａ、ｂおよびｃは、式（Ｂ－ＰＣ）中のａの値、ｂの値およびｃの値を示す。（ＰＣ）は、上記式（ＰＣ）で示される構造単位の具体例を示す。（Ｂ－ＰＣ）／（ＰＣ）は、式（Ｂ－ＰＣ）で示される構造単位と式（ＰＣ）で示される構造単位の共重合比（質量比）を示す。Ｍｗは、重量平均分子量を示す。

Table 2 shows examples of polycarbonate resins containing a structural unit represented by formula (B-PC) and a structural unit represented by formula (PC). In Table 2, a, b, and c indicate the values of a, b, and c in formula (B-PC). (PC) indicates a specific example of the structural unit represented by formula (PC). (B-PC)/(PC) indicates the copolymerization ratio (mass ratio) of the structural unit represented by formula (B-PC) and the structural unit represented by formula (PC). Mw indicates the weight average molecular weight.

表３には、式（Ｃ－ＰＣ）で示される構造単位と式（ＰＣ）で示される構造単位を含むポリカーボネート樹脂を例示する。表３中、ｄは、式（Ｃ－ＰＣ）中のｄの値を示す。Ｚの値は、アルキレン基を構成する炭素数を示す。（ＰＣ）は、ポリカーボネート樹脂の主鎖を構成する構造単位を示す。Ｍｗは、重量平均分子量を示す。

Table 3 shows examples of polycarbonate resins containing a structural unit represented by formula (C-PC) and a structural unit represented by formula (PC). In Table 3, d indicates the value of d in formula (C-PC). The value of Z indicates the number of carbon atoms constituting the alkylene group. (PC) indicates the structural unit constituting the main chain of the polycarbonate resin. Mw indicates the weight average molecular weight.

Among these, the polycarbonate resins (A-PC-1), (A-PC-2), (A-PC-3), (B-PC-1), (B-PC-2), (B-PC-3), (C-PC-1) and (C-PC-2) are preferred, with (A-PC-2), (B-PC-2) and (C-PC-2) being particularly preferred.

式（Ａ－Ｅ）中、Ｘ^１は、ｍ－フェニレン基、ｐ－フェニレン基、または２つのｐ－フェニレン基が酸素原子を介して結合した２価の基を示す。 A specific example of a polyester resin containing a siloxane moiety having the structure represented by formula (A) is a resin having a structural unit represented by formula (AE).

In formula (AE), ^X1 represents an m-phenylene group, a p-phenylene group, or a divalent group in which two p-phenylene groups are bonded via an oxygen atom.

式（Ｂ－Ｅ）中、Ｘ^２は、ｍ－フェニレン基、ｐ－フェニレン基、または２つのｐ－フェニレン基が酸素原子を介して結合した２価の基を示す。 A specific example of a polyester resin containing a siloxane moiety having the structure represented by formula (B) is a resin having a structural unit represented by formula (BE).

In formula (BE), ^X2 represents an m-phenylene group, a p-phenylene group, or a divalent group in which two p-phenylene groups are bonded via an oxygen atom.

式（Ｃ－Ｅ）中、Ｘ^３は、ｍ－フェニレン基、ｐ－フェニレン基、または２つのｐ－フェニレン基が酸素原子を介して結合した２価の基を示す。 A specific example of a polycarbonate resin containing a siloxane moiety having the structure represented by formula (C) is a resin having a structural unit represented by formula (CE) at its terminal.

In formula (CE), ^X3 represents an m-phenylene group, a p-phenylene group, or a divalent group in which two p-phenylene groups are bonded via an oxygen atom.

式（Ｅ）中、Ｒ^５～Ｒ^８は、それぞれ独立に水素原子、またはメチル基を示す。Ｙ^２は、置換基としてアルキル基を有してもよいメチレン基、シクロヘキシリデン基、酸素原子または単結合を示す。Ｘ^４は、ｍ－フェニレン基、ｐ－フェニレン基、または２つのｐ－フェニレン基が酸素原子を介して結合した２価の基を示す。 The polyester resin containing a siloxane moiety has a structural unit represented by formula (A-E) or formula (B-E) or a structural unit represented by formula (C-E) at its terminal, but may be a copolymer resin with other structural units. Examples of the other structural units include the structural unit represented by formula (E).

In formula (E), ^R5 to ^R8 each independently represent a hydrogen atom or a methyl group. ^Y2 represents a methylene group which may have an alkyl group as a substituent, a cyclohexylidene group, an oxygen atom or a single bond. ^X4 represents an m-phenylene group, a p-phenylene group or a divalent group in which two p-phenylene groups are bonded via an oxygen atom.

Specific examples of the structural unit represented by formula (E) are given below.

Among these, structural units represented by formulae (E-1), (E-7), (E-13), (E-14) and (E-18) are preferred, and structural units represented by formulae (E-1) and (E-7) are particularly preferred.

The polyester resin containing a siloxane moiety may be a polyester resin that combines a structural unit represented by formula (A-E) or a structural unit represented by formula (B-E) and a structural unit represented by formula (E).

When the polyester resin containing siloxane moieties has a structural unit represented by formula (E) in addition to the structural unit represented by formula (A-E) or the structural unit represented by formula (B-E), it is preferable that the total content of the structural unit represented by formula (A-E) and the structural unit represented by formula (B-E) is 6% by mass or more and 40% by mass or less relative to the total mass of the polyester resin containing siloxane moieties. It is also preferable that the content of the structural unit represented by formula (E) is 60% by mass or more and 94% by mass or less relative to the total mass of the polyester resin containing siloxane moieties. More preferably, the total content of the structural unit represented by formula (A-E) and the structural unit represented by formula (B-E) is 10% by mass or more and 20% by mass or less relative to the total mass of the polyester resin containing siloxane moieties, and the content of the structural unit represented by formula (E) is 60% by mass or more and 90% by mass or less relative to the total mass of the polyester resin containing siloxane moieties.

When a polyester resin containing a siloxane moiety has a structural unit represented by formula (E) in addition to the structural unit represented by formula (A-E) or the structural unit represented by formula (B-E), the polyester resin containing a siloxane moiety is a copolymer containing the structural unit represented by formula (A-E) or the structural unit represented by formula (B-E) and the structural unit represented by formula (E). The copolymerization form may be any of block copolymerization, random copolymerization, alternating copolymerization, etc.

The polyester resin containing a siloxane moiety may be a resin having a structural unit represented by formula (C-E) at the end of a polyester resin that combines multiple structures from the structural unit represented by formula (E).

When a polyester resin containing a siloxane moiety has a structural unit represented by formula (C-E) at the end of a polyester resin containing a structural unit represented by formula (E), the content of the structural unit represented by formula (C-E) is preferably 0.5% by mass or more and 3% by mass or less relative to the total mass of the polyester resin containing a siloxane moiety. It is further preferably 0.8% by mass or more and 2% by mass or less.

The weight average molecular weight of the polyester resin containing a siloxane moiety is preferably 50,000 or more and 150,000 or less. It is even more preferably 60,000 or more and 120,000 or less. The weight average molecular weight is a polystyrene-equivalent weight average molecular weight measured according to a conventional method, specifically, by the method described in JP-A-2007-79555.

The copolymerization ratio of the polyester resin containing a siloxane moiety can be confirmed by a general method of converting the peak area ratio of hydrogen atoms (hydrogen atoms constituting the resin) in ¹ H-NMR measurement of the resin.

表４には、式（Ａ－Ｅ）で示される構造単位と式（Ｅ）で示される構造単位を含むポリエステル樹脂を例示する。表４中、ｎおよびＸ^１は、式（Ａ－Ｅ）中のｎの値およびＸ^１を構成する構造を示す。（Ｅ）は、上記式（Ｅ）で示される構造単位の具体例および共重合比（質量比）を示す。（Ａ－Ｅ）／（Ｅ）は、式（Ａ－Ｅ）で示される構造単位と式（Ｅ）で示される構造単位の共重合比（質量比）を示す。Ｍｗは、重量平均分子量を示す。 Tables 4-6 list examples of polyester resins containing siloxane moieties according to the present invention.

Table 4 shows examples of polyester resins containing structural units represented by formulas (A-E) and (E). In Table 4, n and ^X1 indicate the value of n in formulas (A-E) and the structure constituting ^X1 . (E) indicates specific examples of structural units represented by formula (E) and the copolymerization ratio (mass ratio). (A-E)/(E) indicates the copolymerization ratio (mass ratio) of the structural units represented by formulas (A-E) and (E). Mw indicates the weight average molecular weight.

表５には、式（Ｂ－Ｅ）で示される構造単位と式（Ｅ）で示される構造単位を含むポリエステル樹脂を例示する。表５中、ａ、ｂ、ｃおよびＸ^２は、式（Ｂ－Ｅ）中のａの値、ｂの値およびｃの値並びにＸ^２を構成する構造を示す。（Ｅ）は、上記式（Ｅ）で示される構造単位の具体例を示す。（Ｂ－Ｅ）／（Ｅ）は、式（Ｂ－Ｅ）で示される構造単位と式（Ｅ）で示される構造単位の共重合比（質量比）を示す。Ｍｗは、重量平均分子量を示す。

Table 5 shows examples of polyester resins containing a structural unit represented by formula (B-E) and a structural unit represented by formula (E). In Table 5, a, b, c, and ^X2 indicate the values of a, b, and c in formula (B-E) and the structure constituting ^X2 . (E) shows specific examples of the structural unit represented by formula (E). (B-E)/(E) indicates the copolymerization ratio (mass ratio) of the structural unit represented by formula (B-E) and the structural unit represented by formula (E). Mw indicates the weight average molecular weight.

表６には、式（Ｃ－Ｅ）で示される構造単位と式（Ｅ）で示される構造単位を含むポリエステル樹脂を例示する。表６中、ｄは、式（Ｃ－Ｅ）中のｄの値およびを示す。Ｚの値は、アルキレン基を構成する炭素数を示す。Ｘ^３は、式（Ｃ－Ｅ）中のＸ^３を構成する構造を示す。（Ｅ）は、ポリエステル樹脂の主鎖を構成する構造単位を示す。Ｍｗは、重量平均分子量を示す。

Table 6 shows examples of polyester resins containing a structural unit represented by formula (C-E) and a structural unit represented by formula (E). In Table 6, d indicates the value of d in formula (C-E). The value of Z indicates the number of carbon atoms constituting the alkylene group. ^X3 indicates the structure constituting ^X3 in formula (C-E). (E) indicates the structural unit constituting the main chain of the polyester resin. Mw indicates the weight average molecular weight.

Among these, the polyester resins (A-E-2), (B-E-2), and (C-E-2) are preferred.

In the present invention, the siloxane moiety refers to a moiety that includes the silicon atoms at both ends constituting the siloxane moiety, groups bonded thereto, and an oxygen atom, a silicon atom, and groups bonded thereto, sandwiched between the silicon atoms at both ends. Specifically, in the present invention, the siloxane moiety refers to the moiety surrounded by the dashed line in the structure represented by formula (A) in the case of the structure represented by formula (A-S).

In the case of the structure represented by formula (B), it refers to the site surrounded by the dashed line in the structure represented by formula (B-S).

In the case of the structure represented by formula (C), it refers to the site surrounded by the dashed line in the structure represented by formula (C-S).

In the present invention, the surface layer of the electrophotographic photoreceptor is characterized by containing a resin containing a siloxane moiety, but a resin not containing a siloxane moiety may be mixed in. Such a resin is arbitrary, but a polycarbonate resin not containing a siloxane moiety or a polyester resin not containing a siloxane moiety is preferable in terms of maintaining durability with repeated use of the electrophotographic photoreceptor.

The polycarbonate resin that does not contain a siloxane moiety preferably has a structural unit represented by formula (PC). Similarly, the polyester resin that does not contain a siloxane moiety preferably has a structural unit represented by formula (E). The weight average molecular weight (Mw) of the polycarbonate resin that does not contain a siloxane moiety or the polyester resin that does not contain a siloxane moiety is preferably 60,000 or more and 160,000 or less in terms of maintaining durability, and more preferably 80,000 or more and 140,000 or less.

When a resin containing a siloxane moiety and a resin other than the resin containing a siloxane moiety are mixed in the surface layer, the content of the resin containing a siloxane moiety relative to the total mass of the components in the surface layer is preferably 0.1% by mass or more and 10% by mass or less from the viewpoint of the fogging reduction effect of the present invention. It is further preferably 0.3% by mass or more and 8% by mass or less.

[Process Cartridge, Electrophotographic Apparatus]
The process cartridge of the present invention is characterized in that it has a developing means containing the toner described above and an electrophotographic photosensitive member, and is detachably mountable to the main body of the electrophotographic apparatus.
The electrophotographic apparatus of the present invention is characterized by having a toner and an electrophotographic photosensitive member.

FIG. 1 shows an example of a schematic configuration of an electrophotographic apparatus having a process cartridge equipped with an electrophotographic photosensitive member.
A cylindrical electrophotographic photoreceptor 1 is driven to rotate around an axis 2 at a predetermined peripheral speed in the direction of the arrow. The surface of the electrophotographic photoreceptor 1 is charged to a predetermined positive or negative potential by a charging means 3. Although the figure shows a roller charging method using a roller-type charging member, a corona charging method, a proximity charging method, an injection charging method, or other charging methods may be adopted. Exposure light 4 is irradiated from an exposure means (not shown) onto the charged surface of the electrophotographic photoreceptor 1, and an electrostatic latent image corresponding to the target image information is formed. The electrostatic latent image formed on the surface of the electrophotographic photoreceptor 1 is developed with toner contained in a developing means 5, and a toner image is formed on the surface of the electrophotographic photoreceptor 1. The toner image formed on the surface of the electrophotographic photoreceptor 1 is transferred to a transfer material 7 by a transfer means 6. The transfer material 7 to which the toner image has been transferred is transported to a fixing means 8, where the toner image is fixed, and the transfer material 7 is printed out outside the electrophotographic device. The electrophotographic device may have a cleaning means 9 for removing deposits such as toner remaining on the surface of the electrophotographic photoreceptor 1 after transfer. Also, a so-called cleanerless system may be used in which the deposits are removed by the developing unit 5 or the like without providing a separate cleaning unit 9. The electrophotographic apparatus may have a charge eliminating mechanism that eliminates charge on the surface of the electrophotographic photoreceptor 1 by pre-exposure light 10 from a pre-exposure unit (not shown). Also, in order to make the process cartridge 11 of the present invention detachable from the main body of the electrophotographic apparatus, guide unit 12 such as a rail may be provided.

The electrophotographic photoreceptor of the present invention can be used in laser beam printers, LED printers, copiers, etc.

The present invention will be specifically described with reference to the following examples. However, these are not intended to limit the present invention in any way. The toner and the method for producing the toner will be described below. In the examples and comparative examples, "parts" and "%" are all based on mass unless otherwise specified. Examples 9 to 13, 21, 22, 25 and 26 are reference examples.

<Production Example of Toner Base Particle Dispersion>
(Preparation of aqueous medium)
11.2 parts of sodium phosphate (12-hydrate) was added to a reaction vessel containing 390.0 parts of ion-exchanged water to prepare an aqueous sodium phosphate solution, which was then kept warm at 65°C for 1.0 hours while being purged with nitrogen. While stirring the aqueous sodium phosphate solution at 12,000 rpm using a stirring device (trade name: T.K. Homomixer, manufactured by Tokushu Kika Kogyo Co., Ltd.), an aqueous calcium chloride solution in which 7.4 parts of calcium chloride (2-hydrate) was dissolved in 10.0 parts of ion-exchanged water was added to the reaction vessel all at once to prepare an aqueous medium containing a dispersion stabilizer. Furthermore, 1.0 mol/L of hydrochloric acid was added to the aqueous medium in the reaction vessel to adjust the pH to 6.0, and an aqueous medium was prepared.

(Preparation of Polymerizable Monomer Composition)
The above materials were put into an attritor (manufactured by Nippon Coke & Engineering Co., Ltd.), and further dispersed at 220 rpm for 5.0 hours using zirconia particles having a diameter of 1.7 mm to prepare a colorant dispersion in which the pigment was dispersed.
The following materials were then added to the colorant dispersion:
Styrene 10.0 parts n-Butyl acrylate 30.0 parts Polyester resin 5.0 parts (condensation polymer of terephthalic acid and 2 moles of propylene oxide adduct of bisphenol A, weight average molecular weight Mw=10,000, acid value: 8.2 mgKOH/g)
Paraffin wax (product name: HNP9, manufactured by Nippon Seiro Co., Ltd., melting point: 76°C)
The above materials were kept at 65° C. and uniformly dissolved and dispersed at 500 rpm using a stirrer to prepare a polymerizable monomer composition.

(Granulation process)
While maintaining the temperature of the aqueous medium at 70° C. and the rotation speed of the stirring device at 12,000 rpm, the polymerizable monomer composition was charged into the aqueous medium, and 8.0 parts of t-butyl peroxypivalate as a polymerization initiator was added. Granulation was continued for 10 minutes while maintaining the stirring device at 12,000 rpm.

(Polymerization process)
The stirring device was changed to a stirrer equipped with a propeller stirring blade, and polymerization was carried out for 5.0 hours while maintaining 70° C. with stirring at 200 rpm, and then the temperature was raised to 85° C. and heated for 2.0 hours to carry out a polymerization reaction. The temperature was then raised to 98° C. and heated for 3.0 hours to remove residual monomers, and ion-exchanged water was added to adjust the toner base particle concentration in the dispersion to 30.0%, thereby obtaining a toner base particle dispersion in which the toner base particles are dispersed.
The toner base particles had a number average particle size (D1) of 6.2 μm and a weight average particle size (D4) of 6.9 μm.

<Example of manufacturing organosilicon compound liquid>
The above materials were weighed into a 200 mL beaker, and the pH was adjusted to 3.5 with 10% hydrochloric acid. After that, the mixture was heated to 60° C. in a water bath and stirred for 1.0 hour to prepare an organosilicon compound liquid.

<Production Example of Polyvalent Acid Metal Salt Fine Particles>
・Ion exchange water 100.0 parts・Sodium phosphate (12-hydrate) 8.5 parts After mixing the above materials, at room temperature, using a stirring device (trade name: T.K. Homomixer, manufactured by Tokushu Kika Kogyo Co., Ltd.), 60.0 parts (equivalent to 7.2 parts as zirconium lactate ammonium salt) of zirconium lactate ammonium salt (trade name: ZC-300, Matsumoto Fine Chemical Co., Ltd.) was added while stirring at 10,000 rpm. 1.0 mol/L hydrochloric acid was added to the reaction solution to adjust the pH to 7.0. The temperature of the reaction solution was adjusted to 25 ° C., and the reaction was carried out for 1 hour while maintaining stirring.
The solid content was then removed by centrifugation. The process of dispersing again in ion-exchanged water and removing the solid content by centrifugation was repeated three times to remove ions such as sodium. The resultant was dispersed again in ion-exchanged water and dried by spray drying to obtain fine particles of a zirconium phosphate compound having a number-average particle size of 124 nm.

<Production Example of Toner Particles>
<Toner Particle 1>
(Convex forming process)
The following samples were weighed and placed in a reaction vessel, and mixed using a propeller impeller to obtain a mixed liquid.
Toner base particle dispersion liquid: 500.0 parts Organosilicon compound liquid: 35.0 parts Next, the pH of the resulting mixed liquid was adjusted to 9.5 using a 1.0 mol/L NaOH aqueous solution, and the temperature of the mixed liquid was increased to 50° C., after which the mixture was maintained for 1.0 hour while being mixed using a propeller stirring blade.

(Polyvalent acid metal salt attachment process)
Titanium lactate 44% aqueous solution (product name: TC-310, manufactured by Matsumoto Fine Chemical Co., Ltd.) 3.2 parts (corresponding to 1.4 parts as titanium lactate)
Organosilicon compound liquid 10.0 parts Next, after mixing the above materials in a reaction vessel, the pH of the resulting mixture was adjusted to 9.5 using 1.0 mol/L NaOH aqueous solution and held for 4.0 hours. After lowering the temperature to 25°C, the pH was adjusted to 1.5 using 1.0 mol/L hydrochloric acid and stirred for 1.0 hour, and then filtered while washing with ion-exchanged water. The obtained powder was dried in a thermostatic chamber and classified using a wind classifier to obtain toner particles 1. The number-average particle diameter (D1) of toner particles 1 was 6.2 μm and the weight-average particle diameter (D4) was 6.9 μm. When toner particles 1 were analyzed and observed using a transmission electron microscope and energy dispersive X-ray spectroscopy (TEM-EDX), convex portions containing an organosilicon polymer were observed on the toner particle surface, and it was confirmed that titanium was present on the surface of the convex portions. The convex height H was 60 nm. Furthermore, when the toner particles 1 were analyzed by time-of-flight secondary ion mass spectrometry (TOF-SIMS analysis), ions derived from titanium phosphate were detected.
The titanium phosphate compound is a reaction product of titanium lactate and phosphate ions derived from sodium phosphate or calcium phosphate derived from an aqueous medium.

<Toner Particles 2>
(Polyvalent acid metal salt attachment process)
The following samples were weighed and placed in a reaction vessel, and mixed using a propeller impeller to obtain a mixed liquid.
Toner base particle dispersion: 500.0 parts Titanium lactate 44% aqueous solution (product name: TC-310, manufactured by Matsumoto Fine Chemical Co., Ltd.) 3.2 parts (corresponding to 1.4 parts as titanium lactate)
Organosilicon compound liquid 10.0 parts Next, the pH of the resulting mixed liquid was adjusted to 9.5 using 1.0 mol/L NaOH aqueous solution and held for 5.0 hours. After lowering the temperature to 25°C, the pH was adjusted to 1.5 using 1.0 mol/L hydrochloric acid and stirred for 1.0 hour, and then filtered while washing with ion-exchanged water. The obtained powder was dried in a thermostatic chamber and classified using a wind classifier to obtain toner particles 2. The number-average particle diameter (D1) of toner particles 2 was 6.2 μm and the weight-average particle diameter (D4) was 6.9 μm. When toner particles 2 were observed using TEM-EDX, it was found that an organosilicon polymer was present on the toner particle surface, but no protrusions were formed. It was also confirmed that titanium was present on the surface of the toner particles. Furthermore, ions derived from titanium phosphate were detected by TOF-SIMS analysis of toner particles 2.
The titanium phosphate compound is a reaction product of titanium lactate and phosphate ions derived from sodium phosphate or calcium phosphate derived from an aqueous medium.

<Toner Particle 3>
Toner particles 3 were obtained in the same manner as in the production example of toner particles 2, except that 11.7 parts of zirconium lactate ammonium salt (product name: ZC-300, Matsumoto Fine Chemical Co., Ltd.) (corresponding to 1.4 parts as zirconium lactate ammonium salt) were added instead of 3.2 parts of titanium lactate 44% aqueous solution (product name: TC-310, Matsumoto Fine Chemical Co., Ltd.). The number average particle size (D1) of toner particles 3 was 6.2 μm, and the weight average particle size (D4) was 6.9 μm. When toner particles 3 were observed by TEM-EDX, an organosilicon polymer was present on the toner particle surface, but no convex portions were formed. In addition, it was confirmed that zirconium was present on the surface of the toner particles. Furthermore, ions derived from zirconium phosphate were detected by TOF-SIMS analysis of toner particles 3.
The zirconium phosphate compound is a reaction product of zirconium lactate ammonium salt and phosphate ions derived from sodium phosphate or calcium phosphate derived from an aqueous medium.

<Toner Particle 4>
The following samples were weighed and placed in a reaction vessel, and mixed using a propeller agitator.
Toner base particle dispersion 500.0 parts Next, while maintaining the temperature at 25° C., the pH was adjusted to 1.5 with 1.0 mol/L hydrochloric acid, and the mixture was stirred for 1.0 hour, and then filtered while being washed with ion-exchanged water. The obtained powder was dried in a thermostatic chamber and classified with an air classifier to obtain toner particles 4.

<Toner Particle 5>
Toner particles 5 were obtained in the same manner as in the production example of toner particles 2, except that a 44% aqueous solution of titanium lactate (product name: TC-310, manufactured by Matsumoto Fine Chemical Co., Ltd.) was not added. The number average particle size (D1) of toner particles 5 was 6.2 μm, and the weight average particle size (D4) was 6.9 μm. When toner particles 5 were observed by TEM-EDX, an organosilicon polymer was present on the toner particle surface, but no convex portions were formed. Furthermore, no metal elements were present on the surface of the toner particles. Furthermore, when toner particles 5 were analyzed by TOF-SIMS, no ions derived from polyvalent acid metal salts were detected.

<Toner Manufacturing Method>
<Toner 1, 2, 3, 5>
Toner particles 1, 2, 3 and 5 were used as toners 1, 2, 3 and 5.

<Toner 4>
Toner particles 4 100.0 parts Hydrophobic silica fine particles (treated with hexamethyldisilazane: number average particle size 12 nm) 1.0 parts Polyvalent acid metal salt fine particles 2.0 parts The above materials were put into a SUPERMIXER PICCOLO SMP-2 (manufactured by Kawata Co., Ltd.) and mixed at 3,000 rpm for 20 minutes. Thereafter, the mixture was sieved through a mesh with an opening of 150 μm to obtain toner 4. The number average particle size (D1) of toner 4 was 6.2 μm, and the weight average particle size (D4) was 6.9 μm. When toner 4 was observed by TEM-EDX, no organosilicon polymer was present on the toner particle surface. In addition, it was confirmed that zirconium was present on the surface of the toner particles. When toner 4 was analyzed by TOF-SIMS, ions derived from zirconium phosphate were detected.
The physical properties of Toners 1 to 5 are shown in Table 7.

<Calculation method of convex height H>
The cross section of a toner particle is observed using a transmission electron microscope (TEM) by the following method.
First, toner particles are thoroughly dispersed in a room temperature curable epoxy resin, and then the resin is cured in an atmosphere at 40° C. for two days.
A thin sample having a thickness of 50 nm is cut out from the obtained cured product using a microtome equipped with a diamond blade (product name: EM UC7, manufactured by Leica Corporation).
The sample is magnified 500,000 times using a TEM (product name: JEM2800, manufactured by JEOL Ltd.) under conditions of an acceleration voltage of 200 V and an electron beam probe size of 1 mm, and the cross section of the toner particle is observed. In this case, the cross section of the toner particle is selected to have a maximum diameter that is 0.9 to 1.1 times the number average particle diameter (D1) when the same toner is measured according to the measurement method of the number average particle diameter (D1) of toner particles described later. Next, the constituent elements of the cross section of the obtained toner particle are analyzed using energy dispersive X-ray spectroscopy (EDX), and an EDX mapping image (256 x 256 pixels (2.2 nm/pixel), 200 times of accumulation) is created.
In the created EDX mapping image, when a signal derived from silicon element is observed on the surface of the toner base particle, the signal is regarded as an image of the organosilicon polymer. Also, when an image of the organosilicon polymer is continuously observed on the surface of the toner base particle, the line segment connecting the end points of the image of the organosilicon polymer is regarded as the base line. Note that the part where the intensity of the signal derived from silicon becomes equal to the background silicon intensity is regarded as the end point of the image of the organosilicon polymer.
For each baseline, the perpendicular line that has the longest length among the perpendicular lines from the baseline to the image surface of the organosilicon polymer is found, and this maximum length is taken as the convex height. The cross sections of 20 toner particles are analyzed according to the above method, and the average of the obtained convex heights is taken as the convex height H (nm).

<Method of calculating ratios M1 and M2 of metal element M using X-ray photoelectron spectroscopy>
Treatment (a)
160 g of sucrose (Kishida Chemical Co., Ltd.) is added to 100 mL of ion-exchanged water, and dissolved in a hot water bath to prepare a 61.5% sucrose aqueous solution. 31.0 g of the concentrated sucrose aqueous solution and 6 g of Contaminon N (trade name) (a 10% by weight aqueous solution of a neutral detergent for cleaning precision measuring instruments, pH 7, consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) are placed in a centrifuge tube to prepare a dispersion. 1.0 g of toner is added to this dispersion, and the toner clumps are loosened with a spatula or the like. The centrifuge tube is shaken with a shaker at 300 spm (strokes per minute) for 20 minutes. After shaking, the solution is transferred to a glass tube (50 mL) for a swing rotor, and separated in a centrifuge at 3500 rpm for 30 minutes. It is visually confirmed that the toner and the aqueous solution are sufficiently separated, and the toner separated in the top layer is collected with a spatula or the like. The collected toner is filtered using a vacuum filter, and then dried in a dryer for at least 1 hour. The dried product is crushed with a spatula to obtain toner (a).
The toner of the present invention, the toner (a), is measured using X-ray photoelectron spectroscopy as follows, and the M1 and M2 are calculated.

The ratios M1 and M2 of the metal element M are calculated by measuring the toner under the following conditions.
Measurement device: X-ray photoelectron spectrometer (product name: Quantum 2000, manufactured by ULVAC-PHI, Inc.)
X-ray source: Monochrome Al Kα
・Xray Setting: 100 μmφ (25 W (15 KV))
Photoelectron take-off angle: 45 degrees Neutralization conditions: Neutralization gun and ion gun used together Analysis area: 300 x 200 μm
Pass Energy: 58.70 eV
Step size: 0.1.25 eV
・Analysis software: Maltipak (PHI)
Here, for example, the quantitative value of Ti atoms is calculated using the peak of Ti 2p (BE 452 to 468 eV). The quantitative value of Ti element obtained here is designated as M1 (atm %).
The toner of the present invention and the toner (a) are measured using the above method, and the ratios of the metal element M in each toner are designated M1 (atm %) and M2 (atm %), respectively.

<Method for detecting polyvalent acid metal salts>
Using time-of-flight secondary ion mass spectrometry (TOF-SIMS), the polyvalent acid metal salt on the surface of the toner particles is detected by the following method.
The toner sample is analyzed using a TOF-SIMS (product name: TRIFTIV, manufactured by ULVAC-PHI, Inc.) under the following conditions.
Primary ion species: gold ion (Au ⁺ )
Primary ion current value: 2 pA
Analysis area: 300 x 300 ^μm2
・Number of pixels: 256 x 256 pixels
Analysis time: 3 min
Repetition frequency: 8.2 kHz
Charge neutralization: ON
Secondary ion polarity: Positive
Secondary ion mass range: m/z 0.5 to 1850
- Sample substrate: Indium When analysis is performed under the above conditions, if a peak derived from secondary ions containing metal ions and polyvalent acid ions (for example, in the case of titanium phosphate, _TiPO3 (m/z 127), _TiP2O5 (m/z 207), etc.) is detected, it is determined that a _polyvalent acid metal salt is present on the surface of the toner particles.

<Production of Electrophotographic Photoreceptor>
(Production Example 1 of Electrophotographic Photoreceptor)
An aluminum cylinder (JIS-A3003, aluminum alloy) having a diameter of 24 mm and a length of 257.5 mm was used as a support (conductive support).

(Formation of Conductive Layer)
Next, the following materials were prepared:

(Metal oxide particles 1)
As metal oxide particles 1, titanium oxide coated with niobium-doped titanium oxide produced by the following production method was used.
The titanium dioxide core material can be produced by the known sulfuric acid method, in which a solution containing titanium sulfate, titanyl sulfate, etc. is heated and hydrolyzed to produce a metatitanic acid slurry, which is then dehydrated and fired to obtain the titanium dioxide core material.
As the core particles, anatase type titanium oxide particles with an average primary particle size of 200 nm were used. _A titanium niobium sulfate solution containing 33.7 g of titanium in terms of _TiO2 and 2.9 g of niobium in terms of _Nb2O5 was prepared. 100 g of core particles were dispersed in pure water to prepare a 1 L suspension, which was then heated to 60°C. The titanium niobium sulfate solution and 10 mol/L sodium hydroxide were dropped over 3 hours so that the pH of the suspension was 2 to 3. After the entire amount was dropped, the pH was adjusted to near neutral, and a flocculant was added to allow the solids to settle. The supernatant was removed, filtered and washed, and dried at 110°C to obtain an intermediate containing 0.1 wt% of organic matter derived from the flocculant in terms of C. This intermediate was fired in nitrogen gas at 750°C for 1 hour, the temperature was lowered to 450°C, and then fired in oxygen gas for 1 hour to produce metal oxide particles 1.

[Preparation of coating solution for conductive layer]
(Coating solution for conductive layer 1)
A solution was obtained by dissolving 80 parts of a phenolic resin (phenolic resin monomer/oligomer) (product name: Plyofen J-325, manufactured by DIC, resin solid content: 60%, density after curing: 1.3 g/cm ³ ) as a binder material in 60 parts of 1-methoxy-2-propanol as a solvent.
160 parts of metal oxide particles 1 were added to this solution, and the solution was placed in a vertical sand mill using 200 parts of glass beads with an average particle size of 1.0 mm as a dispersion medium, and dispersion treatment was performed for 2 hours under conditions of a dispersion temperature of 23±3°C and a rotation speed of 1500 rpm (circumferential speed of 5.5 m/s) to obtain a dispersion. The glass beads were removed from this dispersion using a mesh. The dispersion after removing the glass beads was pressure-filtered using PTFE filter paper (trade name: PF060, manufactured by Advantec Toyo). 0.015 parts of silicone oil (trade name: SH28 PAINT ADDITIVE, manufactured by Dow Corning Toray) as a leveling agent and 15 parts of silicone resin particles (trade name: Tospearl 120, manufactured by Momentive Performance Materials Co., Ltd., average particle size 2 μm) as a surface roughness imparting agent were added to the dispersion after pressure filtration, and the mixture was stirred to prepare a conductive layer coating solution 1.
This conductive layer coating liquid was dip-coated onto the support and heated at 150° C. for 30 minutes to form a conductive layer having a thickness of 25.0 μm.

(Formation of Undercoat Layer)
The following materials were prepared:
Electron transport material represented by the following formula (ET-1): 4 parts Blocked isocyanate (trade name: Duranate SBN-70D, manufactured by Asahi Kasei Chemicals Co., Ltd.) 5.5 parts Polyvinyl butyral resin (trade name: S-LEC KS-5Z, manufactured by Sekisui Chemical Co., Ltd.) 0.3 parts Zinc (II) hexanoate as a catalyst (manufactured by Mitsuwa Chemical Co., Ltd.) 0.05 parts These were dissolved in a mixed solvent of 50 parts of tetrahydrofuran and 50 parts of 1-methoxy-2-propanol to prepare an undercoat layer coating liquid. This undercoat layer coating liquid was dip-coated on the conductive layer and heated at 170° C. for 30 minutes to form an undercoat layer having a thickness of 0.7 μm.

(Formation of Charge Generation Layer)
Next, 10 parts of hydroxygallium phthalocyanine in a crystalline form having peaks at 7.5° and 28.4° in a chart obtained by CuKα characteristic X-ray diffraction and 5 parts of polyvinyl butyral resin (product name: S-LEC BX-1, manufactured by Sekisui Chemical Co., Ltd.) were prepared. These were added to 200 parts of cyclohexanone, dispersed for 6 hours with a sand mill device using glass beads with a diameter of 0.9 mm, and further diluted with 150 parts of cyclohexanone and 350 parts of ethyl acetate to obtain a coating liquid for a charge generating layer. The obtained coating liquid was dip-coated on the undercoat layer and dried at 95°C for 10 minutes to form a charge generating layer with a film thickness of 0.20 μm. The X-ray diffraction measurement was performed under the following conditions.

[Powder X-ray diffraction measurement]
Measuring equipment used: Rigaku Electric Co., Ltd., X-ray diffraction device RINT-TTRII
X-ray tube: Cu
Tube voltage: 50KV
Tube current: 300mA
Scan method: 2θ/θ scan Scan speed: 4.0°/min
Sampling interval: 0.02°
Start angle (2θ): 5.0°
Stop angle (2θ): 40.0°
Attachment: Standard sample holder Filter: Not used Incident monochromator: Used Counter monochromator: Not used Divergence slit: Open Divergence vertical limiting slit: 10.00 mm
Scattering slit: open Receiving slit: open Flat plate monochromator: used Counter: scintillation counter

この電荷輸送層用塗布液を電荷発生層上に浸漬塗布して塗膜を形成し、塗膜を３０分間１２０℃で乾燥させることによって、膜厚が１６μｍの電荷輸送層を形成した。 (Formation of Charge Transport Layer)
Next, the following materials were prepared:
Compound represented by formula (CTM-1) (charge transport material (hole transport compound)) 9 parts Compound represented by formula (CTM-2) (charge transport material (hole transport compound)) 1 part Resin (A-PC-1) shown in Table 8 as a resin containing a siloxane moiety 1 part Resin having a structural unit represented by formula (PC-7) shown in Table 8 as a resin not containing a siloxane moiety 9 parts These were dissolved in a mixed solvent of 25 parts of o-xylene / 15 parts of methyl benzoate / 35 parts of dimethoxymethane to prepare a coating liquid for a charge transport layer.

This charge transport layer coating liquid was dip coated on the charge generating layer to form a coating film, and the coating film was dried at 120° C. for 30 minutes to form a charge transport layer having a thickness of 16 μm.

In this manner, a cylindrical (drum-shaped) electrophotographic photoreceptor of Production Example 1 was produced, which had a support, an undercoat layer, a charge generating layer, and a charge transport layer in this order.

In Table 8, the content indicates the content (mass%) of the resin containing siloxane moieties relative to the total mass of the components in the surface layer. Mw indicates the weight average molecular weight of the resin that does not have siloxane moieties.

(Electrophotographic Photoreceptor Manufacturing Examples 2 to 34)
In the production of electrophotographic photoreceptors 2 to 34, electrophotographic photoreceptors were produced in the same manner as in Production Example 1, except that the composition of the resin contained in the surface layer was changed as shown in Table 8.

(Electrophotographic Photoreceptor Manufacturing Example 35)
In the production of the electrophotographic photoreceptor 35, the steps up to the formation of the charge generating layer were carried out in the same manner as in Production Example 1 of the electrophotographic photoreceptor.
The following materials were prepared as the materials for the coating liquid for the charge transport layer.
Compound represented by formula (CTM-1) (charge transport material (hole transport compound)) 9 parts Compound represented by formula (CTM-2) (charge transport material (hole transport compound)) 1 part Resin having a structural unit represented by formula (PC-7) 10 parts These were dissolved in a mixed solvent of 25 parts of o-xylene / 15 parts of methyl benzoate / 35 parts of dimethoxymethane to prepare a coating solution for a charge transport layer.
This charge transport layer coating liquid was dip coated on the charge generating layer to form a coating film, and the coating film was dried at 120° C. for 30 minutes to form a charge transport layer having a thickness of 16 μm.
In this manner, a cylindrical (drum-shaped) electrophotographic photoreceptor of Production Example 35 having the support, the conductive layer, the undercoat layer, the charge generating layer and the charge transport layer in this order was produced.

[Examples 1 to 34 and Comparative Examples 1 to 5]
The following evaluations were carried out using the toners 1 to 5 and the electrophotographic photoreceptors of Production Examples 1 to 35 in the combinations shown in Table 9. The evaluation results are shown in Table 9.

The evaluation method and evaluation criteria of the present invention will be described.
The image forming apparatus used was a commercially available laser printer (product name: LBP-712Ci, manufactured by Canon) that was connected to an external high voltage power source and modified to provide an arbitrary potential difference between the charging blade and charging roller, and a modified machine with a process speed of 200 mm/sec and a commercially available process cartridge. The product toner was removed from the inside of the cartridge, and after cleaning with an air blower, 165 g of the toner of the present invention was filled. The product toner was removed from each of the yellow, magenta, and black stations, and yellow, magenta, and black cartridges with the toner remaining amount detection mechanism disabled were inserted for evaluation.

<Evaluation of Image Fog>
In gloss paper mode (1/3 speed), a letter-sized HP Brochure Paper 200g, glossy (basis weight 200g/ ^cm2 ) was used, and a 75mm x 75mm piece of paper (Post-it, 3M Japan Ltd.) was attached to the center to print out a solid white image with a 0% print ratio.
The attached paper was removed from the printout image, and the fog density (%) was calculated from the difference in whiteness between the white background of the printed printout image and the whiteness of the transfer paper, which was measured using a "REFLECTOMETER MODEL TC-6DS" (product name) (manufactured by Tokyo Denshoku Co., Ltd.), to evaluate the image fog. An amber filter was used.

REFERENCE SIGNS LIST 1 Electrophotographic photosensitive member 2 Shaft 3 Charging means 4 Exposure light 5 Developing means 6 Transfer means 7 Transfer material 8 Fixing means 9 Cleaning means 10 Pre-exposure light 11 Process cartridge 12 Guide means

Claims (6)

A process cartridge having a developing means containing a toner and an electrophotographic photosensitive member,
The process cartridge is configured to be detachably mounted in the main body of the electrophotographic apparatus,
the toner is a toner having toner particles,
the toner particles contain a titanium phosphate compound on at least a portion of their surfaces;
the surface layer of the electrophotographic photoreceptor contains a polycarbonate resin containing a siloxane moiety or a polyester resin containing a siloxane moiety;
the content of the polycarbonate resin containing a siloxane moiety or the polyester resin containing a siloxane moiety in the surface layer is 0.1% by mass or more and 10% by mass or less, based on the total mass of the components constituting the surface layer;
The polycarbonate resin containing a siloxane moiety is a resin containing a structural unit represented by the following formula (PC) in an amount of 60 mass % or more and 94 mass % or less based on the total mass of the polycarbonate resin containing a siloxane moiety:
The polyester resin containing a siloxane moiety is a resin containing a structural unit represented by the following formula (E) in an amount of 60 mass % or more and 94 mass % or less based on the total mass of the polyester resin containing a siloxane moiety:
A process cartridge comprising:
(In formula (PC), R ¹ to R ⁴ each independently represent a hydrogen atom or a methyl group. Y ¹ represents a methylene group which may have an alkyl group or a phenyl group as a substituent, a cyclohexylidene group, an oxygen atom, or a single bond.)
(In formula (E), R ⁵ to R ⁸ each independently represent a hydrogen atom or a methyl group. Y ² represents a methylene group which may have an alkyl group as a substituent, a cyclohexylidene group, an oxygen atom or a single bond. X ⁴ represents an m-phenylene group, a p-phenylene group or a divalent group in which two p-phenylene groups are bonded via an oxygen atom.) The siloxane moiety is a moiety having a structure represented by the following formula (A) or a moiety having a structure represented by the following formula (B):
2. The process cartridge according to claim 1.
(In formula (A), n represents the average number of repetitions of the structure in parentheses, and is 10 to 120.)
(In formula (B), a, b, and c each independently represent the average number of repetitions of the structure in parentheses, a and b are 1 or more and 10 or less, and c is 20 or more and 200 or less.) The siloxane moiety is a moiety having a structure represented by the following formula (C):
3. The process cartridge according to claim 1 or 2.
(In formula (C), d represents the average number of repetitions of the structure in parentheses and is 10 to 120. Z represents an alkylene group having 3 or less carbon atoms.) The process cartridge according to any one of claims 1 to 3, wherein the ratio M1 of titanium contained in the titanium phosphate compound to the surface constituent elements of the toner particles, as determined from a spectrum obtained by X-ray photoelectron spectroscopy of the toner, is 1.0 atom% or more and 10.0 atom% or less. An electrophotographic device having a process cartridge according to any one of claims 1 to 4. An electrophotographic apparatus having a developing means containing a toner and an electrophotographic photoreceptor,
the toner is a toner having toner particles,
the toner particles contain a titanium phosphate compound on at least a portion of their surfaces;
the surface layer of the electrophotographic photoreceptor contains a polycarbonate resin containing a siloxane moiety or a polyester resin containing a siloxane moiety;
the content of the polycarbonate resin containing a siloxane moiety or the polyester resin containing a siloxane moiety in the surface layer is 0.1% by mass or more and 10% by mass or less, based on the total mass of the components constituting the surface layer;
The polycarbonate resin containing a siloxane moiety is a resin containing a structural unit represented by the following formula (PC) in an amount of 60 mass % or more and 94 mass % or less based on the total mass of the polycarbonate resin containing a siloxane moiety:
The polyester resin containing a siloxane moiety is a resin containing a structural unit represented by the following formula (E) in an amount of 60 mass % or more and 94 mass % or less based on the total mass of the polyester resin containing a siloxane moiety:
Electrophotographic apparatus.
(In formula (PC), R ¹ to R ⁴ each independently represent a hydrogen atom or a methyl group. Y ¹ represents a methylene group which may have an alkyl group or a phenyl group as a substituent, a cyclohexylidene group, an oxygen atom, or a single bond.)
(In formula (E), R ⁵ to R ⁸ each independently represent a hydrogen atom or a methyl group. Y ² represents a methylene group which may have an alkyl group as a substituent, a cyclohexylidene group, an oxygen atom or a single bond. X ⁴ represents an m-phenylene group, a p-phenylene group or a divalent group in which two p-phenylene groups are bonded via an oxygen atom.)

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