JP7237523B2 - toner - Google Patents

Description

The present invention relates to a toner used in image forming methods such as electrophotography.

Electrophotography is a technology for forming an electrostatic latent image on a uniformly charged photoreceptor and visualizing image information with charged toner, and is used in devices such as copiers and printers. In recent years, copiers and printers have been used in new market areas, and high image stability is required for use in various environments. In order to stabilize images, it is desirable for copiers and printers to stabilize electrostatic and mechanical transport of toner. High fluidity is desired for chemical and mechanical conveying.
Patent Document 1 describes a toner in which two kinds of magnetic powders added have specified shapes in order to uniformize the charge distribution among toner particles. By reducing the amount of toner with an excessive amount of charge or toner with an opposite charge in a high-temperature, high-humidity environment, variations in charge distribution between particles can be suppressed.
Patent Document 2 describes a toner in which the molecular weight of a binder resin is controlled so that the charge distribution in toner particles has the same polarity. Toner scattering and fogging can be suppressed by making the surface potential of all points on the toner surface the same polarity.
Japanese Patent Application Laid-Open No. 2002-200003 describes a toner in which the interparticle force between toner particles is controlled in order to improve toner fluidity in a high-temperature and high-humidity environment.

JP 2017-116792 A JP 2016-126196 A Japanese Patent Application Laid-Open No. 2016-103005

However, in Patent Document 1, in a low-temperature, low-humidity environment, the water content of the toner decreases and the electrical conductivity decreases, so that the localized charges of the toner particles are difficult to diffuse throughout the toner. As a result, variations in the surface potential distribution within the toner particles increase, causing problems such as the occurrence of transfer dust (a phenomenon in which toner scatters around characters and line images) and deterioration of halftone reproducibility.
In Patent Document 2, in a low-temperature and low-humidity environment, as with the toner of Patent Document 1, the localized charges of the toner particles are difficult to diffuse throughout the toner particles, and the variation in the surface potential distribution within the toner particles increases. , there were problems such as generation of transfer dust and deterioration of halftone reproducibility. In addition, since a resin is used to control the chargeability of the toner surface, when high pressure is applied to the toner in a low-temperature, low-humidity environment, the fluidity of the toner is reduced, resulting in a problem of deterioration of the solid followability.
In Patent Document 3, fogging is suppressed in a high-temperature and high-humidity environment, but in a low-temperature and low-humidity environment, an increase in the charge amount of the toner causes the toner to aggregate due to electrostatic attraction, resulting in deterioration of solid followability. There was a problem.
For the reasons described above, there is a demand for a toner that has good solid followability even in a low-temperature, low-humidity environment, reduces the occurrence of transfer dust, and has excellent halftone reproducibility.
SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a toner that exhibits good solid followability even in a low-temperature, low-humidity environment, reduces the occurrence of transfer dust, and excels in halftone reproducibility.

The present invention provides a toner having toner particles containing a colorant and a binder resin,
The toner particles have a surface layer containing an organosilicon polymer,
The force between two particles is 3.3 nN or more and 14.8 nN or less when a toner compact formed by compressing the toner with a load of 78.5 N is measured, and
The toner is characterized in that, in the surface potential distribution of the toner measured by a scanning probe microscope, the coefficient of variation of the surface potential distribution is 33 % or less.

According to the present invention, it is possible to provide a toner that has good solid followability even in a low-temperature, low-humidity environment, generates little transfer dust, and has excellent halftone reproducibility.

(A) and (B) are diagrams showing an example of an apparatus used for measuring the force between two particles.

The toner of the present invention has a two-particle force of 1.0 nN or more and 25.0 nN or less when a toner compact formed by compressing the toner with a load of 78.5 N is measured with a scanning probe microscope. In the surface potential distribution of the toner particles, the coefficient of variation of the surface potential distribution is 50% or less.

The present invention will be described in detail below.

In a low-temperature and low-humidity environment, toner is likely to be charged up in printers and copiers, generating strong electrostatic repulsion between toner particles. As a result, the toner image is biased, and the halftone reproducibility may deteriorate. Conventionally, as a method of suppressing charge build-up of toner, a method of adding a material that leaks charge to toner is known.

By adding a charge-leaking material, excessive charging of the toner could be suppressed. However, the halftone reproducibility was not greatly improved. The mechanism is not clear, but the reason why the halftone reproducibility did not improve greatly is that the charge in the toner particles partially leaks, causing variations in the electrostatic repulsion between the toner particles, resulting in a biased toner image. This is thought to be due to the occurrence of

Therefore, the present inventors thought that if a uniform electrostatic repulsive force acts between toner particles on a developed photoreceptor, the problem of deterioration in halftone reproducibility under a low-temperature, low-humidity environment could be solved. .

As a result of intensive studies by the present inventors, it has been found that if the fluidity of the toner is high under high pressure and if the variation (coefficient of variation) of the surface potential distribution within the toner particles is reduced, the halftone reproducibility deteriorates in a low-temperature, low-humidity environment. I have found that the problem can be solved.

As a result of further investigation, it was found that the problem of deterioration in halftone reproducibility can be solved by reducing the force between two toner particles in order to improve the fluidity of the toner under high pressure.

In order to evaluate whether the halftone reproducibility is excellent or not, it is necessary to observe the halftone image. This is done for the 49th gradation image counting from .

The toner of the present invention has an interparticle force of 1.0 nN or more and 25.0 nN or less in a toner compact formed by compressing the toner with a load of 78.5N. The details of the measurement method will be described later, but after applying a load of 78.5 N to the toner accommodated in the cell divided into upper and lower halves, the maximum tensile breaking force when breaking the cell indicates the distance between the two particles. Force is measured. The compression condition of 78.5N is a value assuming the load applied when the compacted toner in the cartridge passes through the regulating blade on the developing roller.

Further, in the toner of the present invention, the coefficient of variation of the surface potential distribution of the toner particles measured with a scanning probe microscope is 50% or less. Although details of the calculation method will be described later, the coefficient of variation of the surface potential distribution of the toner particles is calculated from the surface potential distribution measured with a KPFM (Kelvin Probe Force Microscope), which is a type of scanning probe microscope. First, the surface potential distribution of the toner particles is measured by applying a voltage to the probe so as to cancel the electrostatic force applied to the probe brought close to the toner surface. By dividing the standard deviation of the surface potential distribution by the average value, the coefficient of variation of the surface potential distribution is calculated.

When the force between the two particles satisfies the above range and the coefficient of variation of the surface potential distribution does not satisfy the above range, the toner particles do not agglomerate on the developing roller even when subjected to high pressure from the regulating blade in a low-temperature, low-humidity environment. Toner particles are developed in isolation. However, due to variations in electrostatic repulsion between toner particles, the toner is biased on the photoreceptor, and halftone reproducibility has not been improved. When the coefficient of variation of the surface potential distribution satisfies the above range and the force between two particles does not satisfy the above range, the toner particles on the photoreceptor are not isolated in a low-temperature and low-humidity environment, and toner particle agglomerates exist. Therefore, the toner particles around the agglomerates are subject to a strong electrostatic force. As a result, the unevenness of the toner increased, and the halftone reproducibility was not improved.

On the other hand, when both the force between the two particles and the variation coefficient of the surface potential distribution satisfy the above ranges, the toner particles are developed in an isolated state, and a uniform static electricity is formed between the developed toner particles according to the surface potential distribution. An electro-repulsive force is generated. As a result, the unevenness of the toner on the photosensitive member is remarkably reduced for the first time, and the halftone reproducibility is improved.

Further, when the force between the two particles is within the above range, the toner on the developing roller does not aggregate even in a low-temperature and low-humidity environment, resulting in good solid followability. More preferably, the force between two particles is 1.0 nN or more and 20.0 nN or less.

Furthermore, since the variation coefficient of the surface potential distribution is within the above range, the ratio of the electrostatic attraction generated by the transfer bias to the mirror image force acting on the toner and the photoreceptor is stable for each toner even in a low temperature and low humidity environment. By making it constant, transfer dust is improved. More preferably, the coefficient of variation of the surface potential distribution is 33% or less.

In the toner of the present invention, the absolute value of the average surface potential distribution is preferably 1.0 V or more and 15.0 V or less. When the absolute value of the average value of the surface potential distribution is within the above range, a stable electrostatic repulsive force acts between toner particles even in a high-temperature and high-humidity environment, resulting in good halftone reproducibility. More preferably, the absolute value of the average value of the surface potential distribution is 2.0V or more and 10.0V.

One means for adjusting the coefficient of variation of the interparticle force and the surface potential distribution within the scope of the present invention is to have a surface layer containing, for example, an organosilicon polymer. By including the organosilicon polymer in the surface layer, the contact area between toner particles can be reduced, and the force between two particles can be reduced. In addition, organosilicon polymers have moderate electrical conductivity. As a result, by including the organosilicon polymer in the surface layer, the localized charge generated in the toner due to triboelectrification can be diffused throughout the toner, and the coefficient of variation of the surface potential distribution can be reduced. It is possible to adjust the coefficient of variation of the force between two particles and the surface potential distribution by selecting materials such as the number of carbon atoms directly bonded to the silicon atoms of the organosilicon polymer and the length of the carbon chain. In addition, it is possible to control the variation coefficient of the force between two particles and the surface potential distribution by adjusting the uneven shape of the surface layer containing the organosilicon polymer and the network structure connecting the protrusions. These adjustments can be made by adjusting the timing and form of addition of the organosilicon polymer, and the pH, temperature, time, etc. when pretreating the organosilicon polymer.

The following method is particularly preferred in the present invention. First, toner base particles are prepared and dispersed in an aqueous medium. Further, the pH of the dispersion in which the base particles are dispersed is adjusted to a pH at which condensation of the organosilicon compound is difficult to proceed. Next, the organosilicon compound is hydrolyzed in a separate vessel and added to the base particle dispersion. After the base particle dispersion and the hydrolyzate of the organosilicon compound are sufficiently stirred and mixed, the pH is adjusted to be suitable for condensation, and the organosilicon polymer is condensed at once to form a surface layer on the surface of the toner.

The hydrolysis reaction carried out in a separate vessel can be carried out at an arbitrary temperature by adding an organosilicon compound to an aqueous medium for hydrolysis adjusted to an arbitrary pH. However, when the pH of the aqueous medium for hydrolysis is adjusted to 2.0 or more and 7.0 or less and the temperature is controlled to 10 ° C. or more and 60 ° C. or less, the hydrolysis reaction rate is high and during the hydrolysis reaction It is preferable because the condensation reaction hardly progresses. From the same viewpoint, the concentration of the organosilicon compound in the aqueous medium for hydrolysis is preferably 1.0% by mass or more and 70.0% by mass or less. When the aqueous medium for hydrolysis and the organosilicon compound undergo phase separation, it is preferable to conduct the hydrolysis reaction while stirring by a known method from the viewpoint of promoting the reaction.

Also, the condensation in the toner base particle dispersion can be carried out at any pH and temperature. However, if the pH is adjusted to 6.0 or more and 12.0 or less and the temperature is controlled to 30° C. or more and 100° C. or less, the condensation reaction proceeds rapidly, which is preferable.

By the above method, the surface layer containing the organosilicon polymer becomes uneven, and a network is formed even between the protrusions. In addition, it is believed that the localized charge generated in the toner is diffused over the entire toner due to the network structure between the formed convexes, thereby reducing the coefficient of variation of the surface potential distribution.

When a surface layer containing an organosilicon polymer is used, the content of the organosilicon polymer in the toner particles is preferably 0.5% by mass or more and 5.0% by mass or less. When the content is within the above range, the mechanical strength of the toner is improved, and cracking and crushing of the toner can be suppressed, thereby suppressing the occurrence of fused toner in the developing device, which is the starting point of development streaks. In a low-temperature and low-humidity environment, when the charge amount of the toner increases, a strong electrostatic attraction is generated between this toner fused matter and the toner that is not cracked or crushed. , the pressure applied between the toner free from cracks and crushing and the toner fused material is reduced. As a result, it is possible to suppress the growth of fused matter caused by successive adhesion of toner particles to toner fused matter, so that development streaks that occur in a low-temperature, low-humidity environment can be greatly reduced. The content of the organosilicon polymer is controlled by the type and amount of the organosilicon compound used to form the organosilicon polymer, the method of producing toner particles during the formation of the organosilicon polymer, reaction temperature, reaction time, reaction solvent and pH. can be done. A method for measuring the content of the organosilicon polymer will be described later.

The organosilicon polymer is preferably a polymer having a partial structure represented by the following formula (R ^a T3).
R ^a —SiO _3/2 (R ^a T3)
(In the formula, R ^a represents a hydrocarbon group having 1 to 6 carbon atoms, an aryl group, or a structure represented by the following formula (i) or formula (ii).

（式（ｉ）および（ｉｉ）において、＊はＲ^aＴ３構造中のＳｉ元素との結合部位を表し、式（ｉｉ）におけるＬは、アルキレン基またはアリーレン基を表す。）

(In formulas (i) and (ii), * represents a bonding site with the Si element in the R ^a T3 structure, and L in formula (ii) represents an alkylene group or an arylene group.)

Of the four valences of Si atoms in the above formula (R ^a T3), one is bonded to R ^a and the remaining three are bonded to O atoms. The O atom forms a state in which both of its two valences are bonded to Si, that is, a siloxane bond (Si--O--Si). Considering Si atoms and O atoms as an organosilicon polymer, since it has two Si atoms and three O atoms, it is expressed as —SiO _3/2 .

The presence of the siloxane-based polymer moiety —SiO _3/2 in the formula (R ^a T3) can be confirmed by ²⁹ Si-NMR measurement of the tetrahydrofuran-insoluble portion of the toner particles. The presence of the vinyl polymer moiety represented by formula (i) and formula (ii) can be confirmed by ¹³ C-NMR measurement of the tetrahydrofuran-insoluble portion of the toner particles.

The toner of the present invention has a peak attributed to the structure of the formula (R ^a T3) with respect to the total peak area of the organosilicon polymer in the chart obtained by ²⁹ Si-NMR measurement of the tetrahydrofuran (THF)-insoluble portion of the toner particles. The area ratio is preferably 20% or more.

A detailed measurement method will be described later, but this means that the organosilicon polymer contained in the toner particles has a partial structure represented by R ^a —SiO _3/2 in an amount of 20% or more. there is As described above, the --SiO _3/2 partial structure means that three of the four valences of Si atoms are bonded to oxygen atoms, and these oxygen atoms are bonded to other Si atoms. If one of the oxygens is a silanol group, the partial structure of the organosilicon polymer is represented by R ^a --SiO _2/2 --OH. Furthermore, if two oxygens are silanol groups, the partial structure will be R ^a —SiO _1/2 (—OH) ₂ . Comparing these structures, more oxygen atoms forming a bridge structure with Si atoms is closer to the silica structure represented by SiO ₂ . Therefore, the larger the -SiO _3/2 skeleton, the lower the surface free energy of the toner particle surface, which is excellent in environmental stability and member contamination resistance. On the other hand, the smaller the —SiO _3/2 skeleton, the more silanol groups having a strong negative charging property, and the charge-up may not be completely suppressed. From the viewpoint of chargeability and durability, it is preferably 100% or less, more preferably 40% or more and 80% or less.

The ratio of the peak area of the partial structure depends on the type and amount of the organosilicon compound used to form the organosilicon polymer, and the reaction temperature, reaction time, and reaction temperature for hydrolysis, addition polymerization, and condensation polymerization during the formation of the organosilicon polymer. It can be controlled by solvent and pH.

When a surface layer containing an organosilicon polymer is used, a backscattered electron image of a 1.5 μm square of the surface of the toner particles is obtained by scanning electron microscope observation of the surface of the toner particles. When obtaining a brightness histogram based on the number of pixels with the brightness of the tone on the horizontal axis, the histogram has two maximum values P1 and P2 and a minimum value V between the P1 and P2, and the P2 is the organic It is a maximum value derived from a silicon polymer, the luminance of P1 is 20 or more and 70 or less, the luminance of P2 is 130 or more and 230 or less, and the number of pixels of P1 and P2 with respect to the total number of pixels of the backscattered electron image Each ratio is 0.50% or more, the total number of pixels with a luminance of 0 or more (Vl-30) or less is A1, and the total of luminance (Vl-29) or more and (Vl+29) or less is based on the luminance Vl of the V. It is more preferable to satisfy the following equations (1) and (2), where AV is the number of pixels, and A2 is the total number of pixels with luminance (V1+30) or more and 255 or less.
(A1/AV)≧1.50 (1)
(A2/AV)≧1.50 (2)

As will be described later, the conditions for obtaining a backscattered electron image in the present invention are set so as to reflect the outermost surface of the toner particles. Under the acquisition conditions, the electron beam penetration region and the X-ray generation region for each element estimated from the Kanaya-Okayama equation are approximately several tens of nanometers.

In the present invention, a surface of a toner particle having a surface layer containing an organosilicon polymer is observed with a scanning electron microscope. It is essential that the histogram has two maximum values P1 and P2 and a minimum value V between P1 and P2 when obtaining a pixel number-based luminance histogram with the luminance of .

In the luminance histogram, lower luminance is darker (black) and higher luminance is brighter (white). A backscattered electron image obtained from a scanning electron microscope is also called a "composition image", in which the smaller the atomic number, the darker it is detected, and the higher the atomic number, the brighter it is detected. Since the toner particles have the organosilicon polymer on the surface, the maximum value P1 with low brightness is derived from the toner particle matrix, and the maximum value P2 with high brightness is derived from the organosilicon polymer.

Here, the base refers to a composition containing carbon as a main component, such as a binder resin and a releasing agent, contained in the toner particles. Further, the fact that P2 is derived from an organosilicon polymer can be confirmed by superimposing an elemental mapping image by energy dispersive X-ray spectroscopy (EDS) obtained by scanning electron microscopy and the backscattered electron image. It is one of the requirements of the present invention that P1 derived from the matrix of the toner particles, P2 derived from the organosilicon polymer, and a bimodal histogram having a minimum value V between P1 and P2 are present.

It is also important that the luminance of P1 is 20 or more and 70 or less and the luminance of P2 is 130 or more and 230 or less. When the luminances of P1 and P2 are separated to some extent and the luminances of P1 and P2 are within a certain range, the peak 1 having the maximum value P1 and the peak 2 having the maximum value P1 overlap less and are separated. become good.

As described above, P1 is derived from the toner particle matrix and P2 is derived from the organosilicon polymer. If the peaks 1 and 2 are well separated, the toner particle base and the organosilicon polymer are efficiently localized on the toner particle surface, and their respective functions described below are more effectively exhibited. Preferably, the luminance of P1 is 20 or more and 60 or less, and the luminance of P2 is 140 or more and 230 or less.

Moreover, it is necessary that the ratio of the number of pixels of P1 and P2 to the total number of pixels of the backscattered electron image is 0.50% or more. Furthermore, based on the luminance Vl of the minimum value V, A1 is the total number of pixels with luminance 0 or more (Vl-30) or less, AV is the total number of pixels with luminance (Vl-29) or more and (Vl+29) or less, and luminance (Vl+30) When the total number of pixels above 255 and below is A2, the following formulas (1) and (2)
(A1/AV)≧1.50 (1)
(A2/AV)≧1.50 (2)
is one of the requirements. Here, the number of pixels A1 with a luminance of 0 or more (Vl-30) or less has a peak 1 with a maximum value of P1 as the main component, and the number of pixels A2 with a luminance of (Vl+30) or more and 255 or less has a maximum value of P2. Peak 2 is the main component. As described above, since P1 is derived from the toner particle base and P2 is derived from the organosilicon polymer, each pixel included in A1 is attributed to the toner particle matrix, and each pixel included in A2 is attributed to the organosilicon polymer. be done.

That is, the larger P1 is, the larger the A1 is, the larger the base component is, and the larger the P2 is, the larger the A2 is, the more the organosilicon polymer component is present on the toner particle surface. As a result, the force between two particles and the coefficient of variation of the surface potential distribution fall within the above ranges, and the low-temperature fixability is improved.

A particularly preferable condition is that the number of pixels of P1 and P2 with respect to the total number of pixels of the backscattered electron image is 0.70% or more and 5.00% or less, and the following formulas (3) and (4)
4.00≧(A1/AV)≧1.70 (3)
4.00≧(A2/AV)≧1.70 (4)
is to satisfy

The brightness and number of pixels of P1 and P2, the brightness Vl of the minimum value V, and the number of pixels A1, A2, and AV are determined by the monomer species of the organosilicon polymer, reaction temperature, reaction time, and Control is possible by reaction solvent and pH.

A typical production example of the organosilicon polymer that can be used in the present invention is a method called a sol-gel method. The sol-gel method is a method in which a liquid raw material is used as a starting material, hydrolyzed and condensation-polymerized, and then gelated through a sol state, and is used in a method for synthesizing glass, ceramics, organic-inorganic hybrids, and nanocomposites. By using this production method, functional materials in various shapes such as surface layers, fibers, bulk bodies, and fine particles can be produced from the liquid phase at low temperatures.

Specifically, the organosilicon polymer present on the surface layer of the toner particles is preferably produced by hydrolysis and polycondensation of a silicon compound represented by alkoxysilane.

By providing the surface layer containing the organosilicon polymer on the toner particles, it is possible to obtain a toner with improved environmental stability, less deterioration in toner performance during long-term use, and excellent storage stability. .

Furthermore, the sol-gel method starts from a liquid and forms a material by gelling the liquid, so various microstructures and shapes can be produced. In particular, when the toner particles are produced in an aqueous medium, the particles are easily precipitated on the surface of the toner particles due to the hydrophilicity of the hydrophilic group such as the silanol group of the organosilicon compound. The fine structure and shape can be adjusted by the reaction temperature, reaction time, reaction solvent, pH, the type and amount of the organometallic compound, and the like.

The organosilicon polymer in the present invention is preferably obtained by condensation polymerization of an organosilicon compound having a structure represented by the following formula (Z).

（式（Ｚ）中、Ｒ₁は、炭素数が１以上６以下の炭化水素基、アリール基、又は下記式（ｉ）あるいは式（ｉｉ）で表される構造を表し、Ｒ₂、Ｒ₃及びＲ₄は、それぞれ独立して、ハロゲン原子、ヒドロキシ基、アセトキシ基、又は、アルコキシ基を表す。）

(In the formula (Z), R ₁ represents a hydrocarbon group having 1 to 6 carbon atoms, an aryl group, or a structure represented by the following formula (i) or formula (ii), and R ₂ and R ₃ and R ₄ each independently represent a halogen atom, a hydroxy group, an acetoxy group, or an alkoxy group.)

（式（ｉ）および（ｉｉ）において、＊はＺ構造中のＳｉ元素との結合部位を表し、式（ｉｉ）におけるＬは、アルキレン基またはアリーレン基を表す。）

(In formulas (i) and (ii), * represents a bonding site with the Si element in the Z structure, and L in formula (ii) represents an alkylene group or an arylene group.)

Hydrophobicity can be improved by the hydrocarbon group of R ₁ , and toner particles with excellent environmental stability can be obtained. In addition, an aryl group that is an aromatic hydrocarbon group such as a phenyl group can also be used as the hydrocarbon group. When the hydrophobicity of R ₁ is high, the variation in charge amount tends to increase in various environments. Therefore, in view of environmental stability, R ₁ is more preferably a hydrocarbon group having 1 to 3 carbon atoms. .

R ₂ , R ₃ and R ₄ are each independently a halogen atom, a hydroxy group, an acetoxy group, or an alkoxy group (hereinafter also referred to as a reactive group). These reactive groups are hydrolyzed, addition-polymerized and polycondensed to form a cross-linked structure, and a toner excellent in member contamination resistance and development durability can be obtained. It is preferably an alkoxy group, and more preferably a methoxy group or an ethoxy group, from the viewpoints of moderate hydrolyzability at room temperature and deposition and coating properties on the surface of the toner particles. Also, the hydrolysis, addition polymerization and condensation polymerization of R ₂ , R ₃ and R ₄ can be controlled by reaction temperature, reaction time, reaction solvent and pH.

To obtain the organosilicon polymer used in the present invention, an organosilicon compound having three reactive groups (R ₂ , R ₃ and R ₄ ) in one molecule excluding R ₁ in the above formula (Z) (hereinafter also referred to as trifunctional silane) may be used singly or in combination.

Examples of the above formula (Z) include the following. Vinyltrimethoxysilane, Vinyltriethoxysilane, Vinyldiethoxymethoxysilane, Vinylethoxydimethoxysilane, Vinyltrichlorosilane, Vinylmethoxydichlorosilane, Vinylethoxydichlorosilane, Vinyldimethoxychlorosilane, Vinylmethoxyethoxychlorosilane, Vinyldiethoxychlorosilane, Vinyl Triacetoxysilane, Vinyldiacetoxymethoxysilane, Vinyldiacetoxyethoxysilane, Vinylacetoxydimethoxysilane, Vinylacetoxymethoxyethoxysilane, Vinylacetoxydiethoxysilane, Vinyltrihydroxysilane, Vinylmethoxydihydroxysilane, Vinylethoxydihydroxysilane, Vinyldimethoxysilane trifunctional vinylsilanes such as hydroxysilane, vinylethoxymethoxyhydroxysilane, vinyldiethoxyhydroxysilane; allyltrimethoxysilane, allyltriethoxysilane, allyldiethoxymethoxysilane, allylethoxydimethoxysilane, allyltrichlorosilane, allylmethoxysilane; dichlorosilane, allylethoxydichlorosilane, allyldimethoxychlorosilane, allylmethoxyethoxychlorosilane, allyldiethoxychlorosilane, allyltriacetoxysilane, allyldiacetoxymethoxysilane, allyldiacetoxyethoxysilane, allylacetoxydimethoxysilane, allylacetoxymethoxyethoxysilane, trifunctional allylsilanes such as allylacetoxydiethoxysilane, allyltrihydroxysilane, allylmethoxydihydroxysilane, allylethoxydihydroxysilane, allyldimethoxyhydroxysilane, allylethoxymethoxyhydroxysilane, allyldiethoxyhydroxysilane; p-styryltri Methoxysilane, Methyltrimethoxysilane, Methyltriethoxysilane, Methyldiethoxymethoxysilane, Methylethoxydimethoxysilane, Methyltrichlorosilane, Methylmethoxydichlorosilane, Methylethoxydichlorosilane, Methyldimethoxychlorosilane, Methylmethoxyethoxychlorosilane, Methyldiethoxy chlorosilane, methyltriacetoxysilane, methyldiacetoxymethoxysilane, methyldiacetoxyethoxysilane, methylacetoxydimethoxysilane, methylacetoxymethoxyethoxysilane, methylacetoxydiethoxysilane, trifunctional methylsilanes such as methyltrihydroxysilane, methylmethoxydihydroxysilane, methylethoxydihydroxysilane, methyldimethoxyhydroxysilane, methylethoxymethoxyhydroxysilane, methyldiethoxyhydroxysilane; ethyltrimethoxysilane, ethyltriethoxysilane, trifunctional ethylsilanes such as ethyltrichlorosilane, ethyltriacetoxysilane, ethyltrihydroxysilane; trifunctional such as propyltrimethoxysilane, propyltriethoxysilane, propyltrichlorosilane, propyltriacetoxysilane, propyltrihydroxysilane; trifunctional butylsilanes such as butyltrimethoxysilane, butyltriethoxysilane, butyltrichlorosilane, butyltriacetoxysilane, butyltrihydroxysilane; hexyltrimethoxysilane, hexyltriethoxysilane, hexyltrichlorosilane; , hexyltriacetoxysilane, hexyltrihydroxysilane; trifunctional phenylsilanes such as phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrichlorosilane, phenyltriacetoxysilane, phenyltrihydroxysilane; Silane. The organosilicon compounds may be used alone or in combination of two or more.

As a result of hydrolytic polycondensation, the content of the organosilicon compound satisfying the formula (Z) is preferably 50 mol % or more, more preferably 60 mol % or more, in the organosilicon polymer.

Further, as a result of hydrolytic polycondensation, an organosilicon compound having the structure of the formula (Z) and an organosilicon compound having four reactive groups in one molecule (tetrafunctional silane), three reactions in one molecule A combination of an organosilicon compound having a group (trifunctional silane), an organosilicon compound having two reactive groups in one molecule (bifunctional silane), or an organosilicon compound having one reactive group (monofunctional silane) You may use the organosilicon polymer obtained by carrying out. Examples of organic silicon compounds that may be used in combination include the following. dimethyldiethoxysilane, tetraethoxysilane, hexamethyldisilazane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxy propyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3- Acryloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriemethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3 -aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane Silane, 3-anilinopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, trimethylsilyl chloride, triethylsilyl chloride, triisopropylsilyl chloride, t-butyldimethylsilyl chloride, N,N'-bis(trimethylsilyl)urea, N,O-bis(trimethylsilyl)trifluoroacetamide, trimethylsilyltrifluoromethanesulfonate, 1,3-dichloro-1 , 1,3,3-tetraisopropyldisiloxane, trimethylsilylacetylene, hexamethyldisilane, 3-isocyanatopropyltriethoxysilane, tetraisocyanatosilane, methyltriisocyanatosilane, vinyltriisocyanatosilane.

In the present invention, it is preferable that the surface layer containing the organosilicon polymer and the base portion are in contact with each other without a gap. As a result, the occurrence of bleeding due to the resin component, release agent, etc. inside the toner particles is suppressed from the surface layer of the toner particles, and a toner excellent in storage stability, environmental stability and development durability can be obtained.

The surface layer may contain resins such as styrene-acrylic copolymer resins, polyester resins and urethane resins, various additives, and the like, in addition to the organosilicon polymer described above.

Specific methods for producing the toner will be described below, but the present invention is not limited to these.

In the first manufacturing method, the toner base particles are obtained and then dispersed in an aqueous medium. An organosilicon compound is added to the toner base particle dispersion liquid for condensation, and then the aqueous medium is removed to obtain toner particles. is the way to get

An example of a method for producing toner base particles is given below.
(1) Suspension polymerization method: A polymerizable monomer composition containing a polymerizable monomer capable of forming a binder resin, a release agent, and, if necessary, a colorant, etc. is granulated in an aqueous medium. Then, the polymerizable monomer is polymerized to obtain toner base particles.
(2) Pulverization method: toner base particles are obtained by melting and kneading a binder resin, a release agent, and optionally a colorant and the like and pulverizing the mixture.
(3) Dissolution suspension method: An organic phase dispersion prepared by dissolving a binder resin, a release agent, and optionally a colorant in an organic solvent is suspended in an aqueous medium, granulated, By removing the organic solvent after the polymerization, toner base particles are obtained.
(4) Emulsion aggregation polymerization method: toner base particles are obtained by aggregating and associating binder resin particles, release agent particles, and, if necessary, particles such as a colorant in an aqueous medium.

In the second production method, a polymerizable monomer composition containing a polymerizable monomer capable of forming a binder resin, an organosilicon compound, a release agent, and, if necessary, a colorant, etc. is mixed in an aqueous medium. In this method, toner particles are obtained by granulating and polymerizing the polymerizable monomer.

As the third manufacturing method, a binder resin, an organic silicon compound, a releasing agent, and, if necessary, a coloring agent, etc. are dissolved/dispersed in an organic solvent to prepare an organic phase dispersion, which is then suspended in an aqueous medium. , granulation and polymerization, followed by removal of the organic solvent to obtain toner particles.

The fourth manufacturing method is a method in which binder resin particles, sol- or gel-state organosilicon compound-containing particles, and, if necessary, colorant particles are aggregated and associated in an aqueous medium to form toner particles. .

In addition, the following are mentioned as an aqueous medium. water; a mixed solvent of water and an alcohol such as methanol, ethanol, or propanol; and the like.

As the method for producing toner particles, among the above-described production methods, the first production method, in which toner base particles are produced by a suspension polymerization method, is most preferred. In the suspension polymerization method, the organosilicon polymer is likely to be uniformly deposited on the surface of the toner particles, and localized charges on the toner surface are less likely to occur, so that transfer dust, which is the effect of the present invention, is improved. The suspension polymerization method will be further described below.

If necessary, other resins may be added to the polymerizable monomer composition. After completion of the polymerization step, the produced particles are collected by washing and filtration, and dried to obtain toner base particles. The temperature may be raised in the second half of the polymerization step. Furthermore, in order to remove unreacted polymerizable monomers or by-products, it is also possible to partially distill off the dispersion medium from the reaction system in the second half of the polymerization process or after the completion of the polymerization process. The surface layer containing the organosilicon polymer may be formed by using a base particle dispersion in which the toner base particles are dispersed without washing, filtering and drying after the polymerization step.

Next, the components contained in the toner will be described. The toner particles having an organosilicon polymer on their surface contain a binder resin, a release agent, a colorant if necessary, and other components.

[Binder resin]
The binder resin is not particularly limited, and conventionally known ones can be used. Preferred examples of the binder resin include vinyl-based resins and polyester resins. Examples of vinyl resins, polyester resins and other binder resins include the following resins or polymers.

Homopolymers of styrene and substituted products thereof such as polystyrene and polyvinyltoluene; styrene-propylene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene copolymers, styrene-methyl acrylate copolymers, styrene - ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-methacrylic acid Ethyl copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer Styrenic copolymers such as coalescence, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, poly Vinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyamide resin, epoxy resin, polyacrylic resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin. These binder resins can be used alone or in combination.

In the present invention, the binder resin preferably contains a carboxyl group from the viewpoint of chargeability, and is preferably a resin produced using a polymerizable monomer containing a carboxyl group. (Meth)acrylic acids, such as α-ethylacrylic acid, crotonic acid, and α-alkyl or β-alkyl derivatives; unsaturated dicarboxylic acids, such as fumaric acid, maleic acid, citraconic acid, itaconic acid; monoacryloyl succinate; unsaturated dicarboxylic acid monoester derivatives such as oxyethyl ester, monoacryloyloxyethylene succinate, monoacryloyloxyethyl phthalate and monomethacryloyloxyethyl phthalate;

As the polyester resin, those obtained by condensation polymerization of the following carboxylic acid component and alcohol component can be used. Carboxylic acid components include terephthalic acid, isophthalic acid, phthalic acid, fumaric acid, maleic acid, cyclohexanedicarboxylic acid, and trimellitic acid. Alcohol components include bisphenol A, hydrogenated bisphenol, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, glycerin, trimethylolpropane, and pentaerythritol.

Moreover, the polyester resin may be a polyester resin containing a urea group. As for the polyester resin, it is preferable not to cap carboxyl groups such as terminals.

In the toner of the present invention, the resin may have a polymerizable functional group for the purpose of improving the viscosity change of the toner at high temperatures. Polymerizable functional groups include vinyl groups, isocyanate groups, epoxy groups, amino groups, carboxyl groups, and hydroxy groups.

[Crosslinking agent]
In order to control the molecular weight of the binder resin constituting the toner particles, a cross-linking agent may be added during the polymerization of the polymerizable monomer.

For example, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, divinylbenzene, bis(4 -acryloxypolyethoxyphenyl)propane, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, Neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol #200, #400, #600 diacrylates, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester type Diacrylates (MANDA, Nippon Kayaku), and methacrylates of the above acrylates.

The amount of the cross-linking agent to be added is preferably 0.001% by mass or more and 15.000% by mass or less based on the polymerizable monomer.

[Release agent]
In the present invention, it is preferable to contain a releasing agent as one of the materials constituting the toner particles. Examples of releasing agents that can be used for the toner particles include paraffin wax, microcrystalline wax, petroleum wax and its derivatives such as petrolatum, montan wax and its derivatives, hydrocarbon wax and its derivatives obtained by the Fischer-Tropsch process, polyethylene, Polyolefin waxes such as polypropylene and derivatives thereof, natural waxes such as carnauba wax and candelilla wax and derivatives thereof, higher aliphatic alcohols, fatty acids such as stearic acid and palmitic acid, or compounds thereof, acid amide waxes, ester waxes , ketones, hydrogenated castor oil and its derivatives, vegetable waxes, animal waxes, and silicone resins. Derivatives include oxides, block copolymers with vinyl-based monomers, and graft-modified products. The content of the release agent is preferably 5.0 parts by mass or more and 20.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin or polymerizable monomer.

[Coloring agent]
The toner of the present invention contains a colorant. Colorants are not particularly limited, and for example, known ones shown below can be used.

Yellow pigments include yellow iron oxide, navels yellow, naphthol yellow S, hansa yellow G, hansa yellow 10G, benzidine yellow G, benzidine yellow GR, quinoline yellow lake, permanent yellow NCG, condensed azo compounds such as tartrazine lake, Isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specific examples include the following.

C. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 155, 168, 180.

Examples of orange pigments include the following.

Permanent Orange GTR, Pyrazolone Orange, Vulcan Orange, Benzidine Orange G, Indanthrene Brilliant Orange RK, Indanthrene Brilliant Orange GK.

Red pigments include red iron oxide, permanent red 4R, lithol red, pyrazolone red, watching red calcium salt, lake red C, laked D, brilliant carmine 6B, brilliant carmine 3B, eoxin lake, rhodamine lake B, condensation of alizarin lake, etc. azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specific examples include the following.

C. I. Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254.

Blue pigments include copper phthalocyanine compounds and their derivatives such as alkali blue lake, victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partial chloride, fast sky blue, and indanthrene blue BG, anthraquinone compounds, and basic dyes. A lake compound etc. are mentioned. Specific examples include the following.

C. I. Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, 66.

Purple pigments include Fast Violet B and Methyl Violet Lake.

Examples of green pigments include Pigment Green B, Malachite Green Lake, and Final Yellow Green G. White pigments include zinc white, titanium oxide, antimony white, and zinc sulfide.

Examples of black pigments include carbon black, aniline black, non-magnetic ferrite, magnetite, and those toned black using the above yellow, red, and blue colorants. These colorants can be used singly or in combination, or in the form of a solid solution.

In addition, depending on the method of producing the toner, it is necessary to pay attention to the polymerization inhibitory property of the colorant and the migration property of the colorant to the dispersion medium. If necessary, the colorant may be surface-treated with a substance that does not inhibit polymerization to modify the surface. In particular, many of dyes and carbon black have polymerization inhibitory properties, so care must be taken when using them.

The content of the colorant is preferably 3.0 parts by mass or more and 15.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin or polymerizable monomer.

[Charge control agent]
In the present invention, the toner particles may contain a charge control agent. A known charge control agent can be used. In particular, a charge control agent that has a high charging speed and can stably maintain a constant charge amount is preferred. Furthermore, when the toner particles are produced by a direct polymerization method, a charge control agent which has a low polymerization inhibitory property and substantially no solubilized substances in an aqueous medium is particularly preferred.

Examples of charge control agents that control toner particles to be negatively chargeable include the following.

As organometallic compounds and chelate compounds, monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids and dicarboxylic acid metal compounds. Others include aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, or esters, phenol derivatives such as bisphenol, and the like. Furthermore, urea derivatives, metal-containing salicylic acid-based compounds, metal-containing naphthoic acid-based compounds, boron compounds, quaternary ammonium salts, and calixarenes are included.

On the other hand, examples of the charge control agent for controlling the toner particles to be positively charged include the following.

nigrosine and nigrosine modifications such as fatty acid metal salts; guanidine compounds; imidazole compounds; tributylbenzylammonium-1-hydroxy-4-naphthosulfonate; and their lake pigments; triphenylmethane dyes and their lake pigments (the lake agents include phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.); metal salts of higher fatty acids; resin charge control agents.

These charge control agents may be contained singly or in combination of two or more. The amount of these charge control agents to be added is preferably 0.01 parts by mass or more and 10.00 parts by mass or less with respect to 100.00 parts by mass of the binder resin.

[External additive]
The toner particles of the present invention can constitute the toner of the present invention without external additives. The toner of the present invention may be configured by adding an auxiliary agent or the like.

Examples of external additives include inorganic oxide fine particles such as silica fine particles, alumina fine particles and titanium oxide fine particles; inorganic stearic acid compound fine particles such as aluminum stearate fine particles and zinc stearate fine particles; Examples include fine particles of inorganic titanate compounds such as zinc oxide. These can be used individually by 1 type or in combination of 2 or more types. These inorganic fine particles are preferably gloss-treated with a silane coupling agent, a titanium coupling agent, a higher fatty acid, a silicone oil, or the like, in order to improve heat-resistant storage stability and environmental stability. The BET specific surface area of the external additive is preferably 10 m ² /g or more and 450 m ² /g or less.

The BET specific surface area can be determined by a low temperature gas adsorption method using a dynamic constant pressure method according to the BET method (preferably the BET multipoint method). For example, using a specific surface area measuring device (trade name: Gemini 2375 Ver.5.0, manufactured by Shimadzu Corporation), nitrogen gas is adsorbed on the surface of the sample, and the BET multipoint method is used for measurement. BET specific surface area (m ² /g) can be calculated.

The total amount of these various external additives added is 0.05 parts by weight or more and 5.0 parts by weight or less, preferably 0.1 parts by weight or more and 3.0 parts by weight, based on 100.0 parts by weight of the toner. It is considered to be below the department. In addition, various external additives may be used in combination.

[Developer]
The toner of the present invention can be used as a magnetic or non-magnetic one-component developer, but may be mixed with a carrier and used as a two-component developer.

As the carrier, magnetic particles made of conventionally known materials such as metals such as iron, ferrite and magnetite, and alloys of these metals with metals such as aluminum and lead can be used. is preferably used. As the carrier, a coated carrier in which the surfaces of magnetic particles are coated with a coating agent such as a resin, or a resin-dispersed carrier in which magnetic fine powder is dispersed in a binder resin may be used.

The carrier preferably has a volume average particle size of 15 μm or more and 100 μm or less, more preferably 25 μm or more and 80 μm or less.

[Method for producing toner particles]
The toner particles of the present invention can be produced by known means such as a kneading pulverization method or a wet production method. A wet production method can be preferably used from the viewpoint of uniformity of particle size and shape controllability. Furthermore, the wet production method includes a suspension polymerization method, a dissolution suspension method, an emulsion polymerization aggregation method, an emulsion aggregation method, and the like.

Here, the suspension polymerization method will be explained. In the suspension polymerization method, first, a polymerizable monomer for synthesizing a binder resin, a colorant and a salicylic acid resin are uniformly dissolved or dispersed using a dispersing machine such as a ball mill or an ultrasonic dispersing machine. Then, a polymerizable monomer composition is prepared (step of preparing a polymerizable monomer composition). At this time, if necessary, a polyfunctional monomer, a chain transfer agent, a wax as a release agent, a charge control agent, a plasticizer, and the like can be appropriately added. As the polymerizable monomer in the suspension polymerization method, the following vinyl-based polymerizable monomers can be suitably exemplified. Styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, p- Styrene derivatives such as n-hexylstyrene, pn-octyl, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p-phenylstyrene; methyl acrylate, ethyl Acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl Acrylic polymerizable monomers such as acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate; methyl methacrylate, ethyl methacrylate, n- Propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, diethylphos methacrylic polymerizable monomers such as phosphate ethyl methacrylate and dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, vinyl benzoate, and vinyl formate vinyl ester; vinyl ether such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropyl ketone.

Next, the polymerizable monomer composition is put into an aqueous medium prepared in advance, and droplets of the polymerizable monomer composition are formed by a stirrer or a disperser having a high shear force. (granulation step).

It is preferable that the aqueous medium in the granulation step contain a dispersion stabilizer in order to control the particle size of the toner particles, sharpen the particle size distribution, and suppress coalescence of the toner particles in the production process. Dispersion stabilizers are generally classified broadly into macromolecules that generate a repulsive force due to steric hindrance and poorly water-soluble inorganic compounds that stabilize dispersion by electrostatic repulsive force. Fine particles of poorly water-soluble inorganic compounds are preferably used because they are dissolved by acid or alkali and can be dissolved and easily removed by washing with acid or alkali after polymerization.

As the dispersion stabilizer for the sparingly water-soluble inorganic compound, one containing any one of magnesium, calcium, barium, zinc, aluminum and phosphorus is preferably used. More preferably, one of magnesium, calcium, aluminum and phosphorus is desired. Specifically, the following are mentioned.

Magnesium phosphate, tricalcium phosphate, aluminum phosphate, zinc phosphate, magnesium carbonate, calcium carbonate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, hydroxyapatide.

Organic compounds such as polyvinyl alcohol, gelatin, methyl cellulose, methylhydroxypropyl cellulose, ethyl cellulose, sodium salts of carboxymethyl cellulose, and starch may be used in combination with the dispersion stabilizer. It is preferable to use 0.01 parts by mass or more and 2.00 parts by mass or less of these dispersion stabilizers with respect to 100.00 parts by mass of the polymerizable monomer. Furthermore, a surfactant of 0.001% by mass or more and 0.1% by mass or less may be used in combination to make these dispersion stabilizers finer. Specifically, commercially available nonionic, anionic, and cationic surfactants can be used. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate and calcium oleate are preferably used.

After the granulation step or while performing the granulation step, polymerization is generally performed at a temperature of 50° C. or higher and 90° C. or lower to obtain a toner particle dispersion (polymerization step).

In the polymerization process, the temperature of the treatment liquid has a great effect on the fixing performance of the toner particles. Therefore, stirring is generally performed so that the temperature distribution in the container is uniform. When a polymerization initiator is added, it can be added at any desired time and required time. Further, in order to obtain a desired molecular weight distribution, the temperature may be raised in the second half of the polymerization reaction, and further, in order to remove unreacted polymerizable monomers, by-products, etc. from the system, the second half of the reaction or the end of the reaction may be heated. Afterwards, a portion of the aqueous medium may be distilled off by a distillation operation. The distillation operation can be performed under normal pressure or reduced pressure.

An oil-soluble initiator is generally used as the polymerization initiator used in the suspension polymerization method. For example:

2,2'-azobisisobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4 - azo compounds such as methoxy-2,4-dimethylvaleronitrile; acetylcyclohexylsulfonyl peroxide, diisopropyl peroxycarbonate, decanonyl peroxide, lauroyl peroxide, stearoyl peroxide, propionyl peroxide, acetyl peroxide, tert- Butyl peroxy-2-ethylhexanoate, benzoyl peroxide, tert-butyl peroxyisobutyrate, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, tert-butyl hydroperoxide, di-tert-butylperoxide peroxide initiators such as oxide, tert-butyl peroxypivalate and cumene hydroperoxide;

If necessary, a water-soluble initiator may be used in combination with the polymerization initiator, and examples thereof include the following.

ammonium persulfate, potassium persulfate, 2,2'-azobis(N,N'-dimethyleneisobutyroamidine) hydrochloride, 2,2'-azobis(2-aminodinopropane) hydrochloride, azobis(isobutylamidine) hydrochloride, sodium 2,2'-azobisisobutyronitrile sulfonate, ferrous sulfate or hydrogen peroxide.

These polymerization initiators can be used alone or in combination, and in order to control the degree of polymerization of the polymerizable monomer, a chain transfer agent, a polymerization inhibitor, etc. can be further added and used.

Regarding the particle size of the toner particles in the present invention, the weight average particle size is preferably 3.0 μm or more and 10.0 μm or less from the viewpoint of obtaining a high-definition and high-resolution image. The weight average particle size of the toner can be measured by a pore electric resistance method. For example, it can be measured using "Coulter Counter Multisizer 3" (manufactured by Beckman Coulter, Inc.). The toner particle dispersion thus obtained is sent to a filtration step for solid-liquid separation of the toner particles and the aqueous medium.

Solid-liquid separation for obtaining toner particles from the obtained toner particle dispersion can be carried out by a general filtration method. It is preferable to carry out further washing, such as by spraying. After sufficient washing is performed, solid-liquid separation is performed again to obtain a toner cake. Thereafter, it is dried by a known drying means, and if necessary, is classified to separate a particle group having a particle size other than the predetermined one to obtain toner particles. The separated particle group having an irregular particle size may be reused in order to improve the final yield.

Various measurement methods related to the present invention are described below. When organic fine powder or inorganic fine powder is externally added to the toner, a toner obtained by removing the organic fine powder or inorganic fine powder by the following method or the like is used as a sample.

160.0 g of sucrose (manufactured by Kishida Chemical Co., Ltd.) is added to 100 mL of ion-exchanged water and dissolved in a hot water bath to prepare a concentrated sucrose solution. 31.0 g of the concentrated sucrose solution and Contaminon N (a neutral detergent for cleaning precision measuring instruments at pH 7 consisting of a nonionic surfactant, an anionic surfactant, and an organic builder) were placed in a centrifugation tube (capacity 50 ml). 6 mL of a 10% by mass aqueous solution of detergent (manufactured by Wako Pure Chemical Industries, Ltd.) is added. 1.0 g of toner is added thereto, and the lumps of toner are loosened with a spatula or the like. The tube for centrifugation is shaken for 20 minutes at 300 spm (strokes per min) in a shaker (AS-1N, sold by As One Co., Ltd.). After shaking, the solution is replaced in a swing rotor glass tube (50 mL) and separated in a centrifuge (H-9R manufactured by Kokusan Co., Ltd.) at 3500 rpm for 30 minutes.

This operation separates the toner particles and the external additive. It is visually confirmed that the toner and the aqueous solution are sufficiently separated, and the separated toner on the uppermost layer is collected with a spatula or the like. After the collected toner is filtered with a vacuum filter, it is dried with a dryer for 1 hour or more to obtain a sample for measurement. This operation is carried out multiple times to ensure the required amount.

<Method for measuring force between two particles>
The force between two toner particles is measured using a Hosokawa Micron Aggrobot according to the instructions for the apparatus.

Specific measurement methods and measurement conditions are as follows.

(Sample conditions)
Charged powder mass: (for magnetic toner) 9.2 (g), (for non-magnetic toner) 7.7 (g)
Binder mass: 0 (g)
True density of powder: True density of toner (kg/m ³ )
Density of liquid binder: 0 (kg/m ³ )
Body area average diameter of powder: Weight average particle diameter of toner (D4) (μm)
Specific surface area shape factor: 6 (-)
Minimum void ratio of dry powder: 0.26 (-)

(Measurement condition)
Environmental temperature: 25°C
Humidity: 50%
Cell inner diameter: 25 mm (see FIG. 1(A))
In-cell height: 37.5 mm (see Fig. 1(A))
Cell temperature: 25°C
Spring wire diameter: 1.0 mm
Compression speed: 1.0mm/sec
Compression holding time: 0.0 sec
Compressive stress: 8 kg/cm ²
Tensile speed: 0.40mm/sec
Tensile sampling start time: 0.0 sec
Tensile sampling time: 25 sec

(1) Magnetic Toner Under the environment of 25° C./50%, 9.2 g of toner is filled into the upper and lower cylindrical cells shown in FIG. 1(A). After that, the compressing rod is lowered at 1.0 mm/sec to apply a vertical load of 78.5 N to form a toner compact.

After that, as shown in FIG. 2B, the upper cell was lifted by a spring at a speed of 0.40 mm/sec to pull the compacted toner, and the maximum tensile breaking force obtained when the compacted toner was broken. Measure the force between two particles (nN) from

(2) Non-Magnetic Toner Under an environment of 25° C./50%, 7.7 g of toner is filled into the upper and lower cylindrical cells shown in FIG. 1(A). After that, the compressing rod is lowered at 1.0 mm/sec to apply a vertical load of 78.5 N to form a toner compact.

Thereafter, as shown in FIG. 1B, the upper cell was lifted by a spring at a speed of 0.40 mm/sec to pull the compacted toner, and the maximum tensile breaking force obtained when the compacted toner was broken. Measure the force between two particles (nN) from

<Method for Calculating Variation Coefficient of Surface Potential Distribution>
The coefficient of variation of the surface potential distribution in the toner was calculated from the surface potential distribution measured by a Kelvin probe force microscope (KPFM).

The KPFM apparatus and observation conditions are as follows.
Apparatus used: Dimension Icon AFM manufactured by Bruker Japan Co., Ltd.
Probe: SCM-PtSi
Measurement mode: Peak force tapping potential feedback method: FM method Scan size: 2.0 μm×2.0 μm
Scan rate: 0.5Hz
Resolution: 256x256
Setpoint: 10nN

In a normal temperature and normal humidity environment (25° C./50% RH), 1.0 g of toner and 19.0 g of magnetic carrier N-01 (manufactured by Imaging Society of Japan) are placed in a 50 mL plastic bottle with a lid and left for 24 hours. After that, it was shaken for 5 minutes at a speed of 4 reciprocations per second with a shaker (YS-LD: manufactured by Yayoi Co., Ltd.) to prepare a two-component developer.

A two-component developer is sprinkled on the medicine-wrapping paper, and a magnet is applied from the back side of the medicine-wrapping paper to fix the two-component developer to the medicine-wrapping paper. A measurement sample for KPFM was prepared by affixing a carbon tape to a stainless steel sample table and transferring toner onto the carbon tape from a two-component developer.

The measurement area is near the vertex where the curvature of the toner particles is the smallest, and the scan size is 2.0 μm×2.0 μm.

The measurement mode is a peak force tapping mode (a measurement mode in which the probe is scanned with a sine wave and the probe is pulled away when the contact pressure reaches a certain level), which contacts the toner with a small force and does not affect the surface potential of the toner. Using. The high-resolution surface potential distribution of the toner was measured in the measurement mode.

KPFM measured the surface potential at each point with a resolution of 256×256. The surface potential average value was calculated by averaging the potential at each point with a resolution of 256×256. The coefficient of variation of the surface potential distribution was calculated by dividing the standard deviation obtained from the surface potential at each of the above measurement points by the absolute value of the average value.

The above procedure was performed for 10 toners , and the average value of each was taken as the physical property value of the toner obtained from the surface potential distribution.

<Measurement of amount of organosilicon polymer in toner>
The amount of organosilicon polymer in the toner was measured by the following method.

The amount of the organosilicon polymer was measured using a wavelength dispersive X-ray fluorescence spectrometer "Axios" (manufactured by PANalytical) and the attached dedicated software "SuperQ ver.4.0F" for setting measurement conditions and analyzing measurement data. (manufactured by PANalytical) is used. Rh is used as the anode of the X-ray tube, the measurement atmosphere is vacuum, the measurement diameter (collimator mask diameter) is 27 mm, and the measurement time is 10 seconds. A proportional counter (PC) is used to measure light elements, and a scintillation counter (SC) is used to measure heavy elements.

As a measurement sample, 4 g of toner particles were placed in a special aluminum ring for press, flattened, and compressed at 20 MPa and 60 using a tableting compressor "BRE-32" (manufactured by Mayekawa Test Instruments Co., Ltd.). A pellet molded to a thickness of 2 mm and a diameter of 39 mm by pressing for 2 seconds is used.

To 100.0 parts by mass of toner particles containing no organosilicon polymer, 0.5 parts by mass of silica (SiO ₂ ) fine powder was added instead of the organosilicon polymer, and the mixture was ground using a coffee mill. Mix well. Similarly, 5.0 parts by mass and 10.0 parts by mass of fine silica powder are mixed with the toner particles, respectively, and these are used as samples for the calibration curve.

For each sample, a pellet of the sample for the calibration curve was prepared as described above using a tablet press, and when PET was used as the analyzing crystal, the diffraction angle (2θ) was observed at 109.08°. Measure the count rate (unit: cps) of Si-Kα rays. At this time, the acceleration voltage and current value of the X-ray generator are set to 24 kV and 100 mA, respectively. A linear function calibration curve is obtained with the obtained X-ray count rate on the vertical axis and the amount of SiO ₂ added in each calibration curve sample on the horizontal axis.

Next, the toner to be analyzed is made into pellets using a tablet press as described above, and the Si--Kα ray count rate of the pellets is measured. Then, the amount of the organosilicon polymer in the toner is determined from the above calibration curve.

<Method for Confirming Partial Structure Represented by Formula (R ^a T3)>
In the present invention, in the partial structure represented by the following formula (R ^a T3), the unit of the hydrocarbon group bonded to the silicon atom was confirmed by ¹³ C-NMR (solid state) measurement. Measurement conditions and sample preparation methods are shown below.
R ^a —SiO _3/2 (R ^a T3)
(In the formula, R ^a represents a hydrocarbon group having 1 to 6 carbon atoms, an aryl group, or a structure represented by the following formula (i) or formula (ii).

（式（ｉ）および（ｉｉ）において、＊はＲ^aＴ３構造中のＳｉ元素との結合部位を表し、式（ｉｉ）におけるＬは、アルキレン基またはアリーレン基を表す。）

(In formulas (i) and (ii), * represents a bonding site with the Si element in the R ^a T3 structure, and L in formula (ii) represents an alkylene group or an arylene group.)

" ¹³ C-NMR (solid) measurement conditions"
Device: JNM-ECX500II manufactured by JEOL RESONANCE
Sample tube: 3.2 mmφ
Sample: 150 mg of tetrahydrofuran-insoluble matter of toner particles for NMR measurement (preparation method below)
Measurement temperature: Room temperature Pulse mode: CP/MAS
Measurement nuclear frequency: 123.25 MHz ( ¹³ C)
Reference substance: adamantane (external standard: 29.5 ppm)
Sample rotation speed: 20 kHz
Contact time: 2ms
Delay time: 2s
Accumulated times: 1024 times

"Sample preparation method"
Preparation of measurement sample: 10.0 g of toner particles were weighed, placed in a filter paper thimble (No. 86R manufactured by Toyo Roshi Kaisha Ltd.), put in a Soxhlet extractor, and extracted with 200 ml of tetrahydrofuran as a solvent for 20 hours. was vacuum-dried at 40° C. for several hours to obtain a sample for NMR measurement.

In the present invention, when the above organic fine powder or inorganic fine powder is externally added to the toner, the organic fine powder or inorganic fine powder is removed by the following method to obtain toner particles.

160 g of sucrose (manufactured by Kishida Chemical Co., Ltd.) is added to 100 mL of ion-exchanged water and dissolved in a hot water bath to prepare a concentrated sucrose solution. In a centrifugation tube, 31 g of the concentrated sucrose solution, Contaminon N (a 10% by mass aqueous solution of a neutral detergent for cleaning precision measuring instruments at pH 7 consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, (manufactured by Wako Pure Chemical Industries, Ltd.) is added to prepare a dispersion. 1.0 g of toner is added to this dispersion, and clumps of toner are loosened with a spatula or the like.

The centrifuge tube is shaken on a shaker at 350 spm (strokes per min) for 20 minutes. After shaking, the solution is replaced in a swing rotor glass tube (50 mL) and separated in a centrifuge at 3500 rpm for 30 minutes. This operation separates the toner particles from the detached external additive. It is visually confirmed that the toner and the aqueous solution are sufficiently separated, and the separated toner on the uppermost layer is collected with a spatula or the like. After filtering the collected toner with a vacuum filter, it is dried with a dryer for 1 hour or more to obtain toner particles. This operation is carried out multiple times to ensure the required amount.

In the above formula (R ^a T3), when R ^a is a partial structure represented by the above formula (i), depending on the presence or absence of a signal due to a methine group (>CH—Si) bonded to a silicon atom, the above The existence of the partial structure represented by the formula (R ^a T3) was confirmed.

In the above formula (R ^a T3), when R ^a is a partial structure represented by the above formula (ii), a methylene group (Si—CH ₂ —) or an ethylene group (Si—C ₂ H ₄ —) or other alkylene group or arylene group, such as a phenylene group (Si—C ₆ H ₄ —), confirms the existence of the unit represented by the above formula (R ^a T3). bottom.

In the above formula (R ^a T3), when R ^a is a partial structure represented by a hydrocarbon group having 1 to 6 carbon atoms or an aryl group, a methyl group (Si—CH ₃ ), ethyl group (Si—C ₂ H ₅ ), propyl group (Si—C ₃ H ₇ ), butyl group (Si—C ₄ H ₉ ), pentyl group (Si—C ₅ H ₁₁ ), hexyl group (Si —C ₆ H ₁₃ ) or an aryl group, such as a phenyl group (Si—C ₆ H ₅ —), confirmed the existence of the unit represented by the above formula (R ^a T3).

<Method for Acquiring Backscattered Electron Image of Surface of Toner Particle>
A backscattered electron image of the surface of the toner particles was obtained with a scanning electron microscope (SEM). The SEM apparatus and observation conditions are as follows.
Apparatus used: ULTRA PLUS manufactured by Carl Zeiss Microscopy Co., Ltd.
Accelerating voltage: 1.0 kV
WD: 2.0mm
Aperture Size: 30.0 μm
Detection signal: EsB (energy selective backscattered electron)
EsB Grid: 800V
Observation magnification: 50,000 times Contrast: 63.0±5.0% (reference value)
Brightness: 38.0±5.0% (reference value)
Resolution: 1024×768
Pretreatment: Sprinkle toner particles on carbon tape (no vapor deposition)

Determine contrast and brightness according to the following procedure. First, the contrast is set so that the two maximum values P1 and P2 have as many pixels as possible on the luminance histogram and the luminances of P1 and P2 are separated as much as possible. Next, the brightness is set so that the skirts of the two peaks having P1 and P2 as the maximum values fall within the luminance histogram. These contrast and brightness are appropriately set according to the above-described procedure according to the state of the device used. Further, the acceleration voltage and EsB grid of the present invention are set so as to achieve items such as acquisition of structural information on the outermost surface of toner particles, prevention of charge-up of an undeposited sample, and selective detection of high-energy backscattered electrons. . The observation field is selected near the vertex where the curvature of the toner particles is the smallest.

<Method for confirming that P2 is derived from an organosilicon polymer>
It was confirmed that P2 was derived from an organosilicon polymer by superimposing an elemental mapping image by energy dispersive X-ray spectroscopy (EDS) obtained with a scanning electron microscope (SEM) and the backscattered electron image.

The SEM/EDS apparatus and observation conditions are as follows.
Apparatus used (SEM): ULTRA PLUS manufactured by Carl Zeiss Microscopy Co., Ltd.
Apparatus used (EDS): NORAN System 7, Ultra Dry EDS Detector manufactured by Thermo Fisher Scientific Co., Ltd.
Accelerating voltage: 5.0 kV
WD: 7.0mm
Aperture Size: 30.0 μm
Detection signal: SE2 (secondary electron)
Observation magnification: 50,000 times Mode: Spectral Imaging
Pretreatment: Sprinkle toner particles on carbon tape and sputter platinum

A mapping image of silicon element obtained by this method is superimposed on the backscattered electron image, and it is confirmed that the silicon atom portion of the mapping image and the bright portion of the backscattered electron image match.

<Method of obtaining luminance histogram>
The luminance histogram is obtained by analyzing the backscattered electron image of the surface of the toner particles obtained by the above method using image processing software ImageJ (developed by Wayne Rashand). The procedure is shown below.

First, the backscattered electron image to be analyzed is converted to 8-bit from Type in the Image menu. Next, from Filters in the Process menu, set the median diameter to 2.0 pixels to reduce image noise. Estimate the center of the image after excluding the observation condition display part displayed at the bottom of the backscattered electron image, and select a 1.5 μm square range from the image center of the backscattered electron image using the Rectangle Tool on the toolbar. .

Next, select Histogram from the Analyze menu to display the brightness histogram in a new window. The numerical value of the brightness histogram is obtained from the list of the window. If necessary, fitting of the luminance histogram may be performed. From this, the luminance and the number of pixels of the maximum values P1 and P2, the luminance Vl of the minimum value V, and the numbers of pixels A1, A2 and AV are calculated.

The above procedure was performed for 10 fields of view for the toner particles to be evaluated, and the average value of each was taken as the physical property value of the toner particles obtained from the luminance histogram.

<Method for Measuring Weight Average Particle Diameter (D4) of Toner Particles>
The weight average particle diameter (D4) of toner is calculated as follows. As a measuring device, a precision particle size distribution measuring device "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is used. The attached dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter, Inc.) is used for setting the measurement conditions and analyzing the measurement data. The measurement is performed with 25,000 effective measurement channels.

As the electrolytic aqueous solution used for measurement, a solution obtained by dissolving special grade sodium chloride in ion-exchanged water to a concentration of about 1% by mass, for example, "ISOTON II" (manufactured by Beckman Coulter, Inc.) can be used.

Before conducting the measurement and analysis, the dedicated software was set as follows.

On the "Change standard measurement method (SOMME)" screen of the dedicated software, set the total count number in control mode to 50000 particles, set the number of measurements to 1, and set the Kd value to "standard particle 10.0 μm" (Beckman Coulter (manufactured by Co., Ltd.) is used to set the value obtained. By pressing the "threshold/noise level measurement button", the threshold and noise level are automatically set. Also, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and put a check in the “Flush aperture tube after measurement” box.

On the "pulse-to-particle size conversion setting" screen of the dedicated software, set the bin interval to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range from 2 μm to 60 μm.

A specific measuring method is as follows.
(1) About 200 ml of the electrolytic aqueous solution is placed in a 250 ml round-bottom glass beaker exclusively for Multisizer 3, set on a sample stand, and stirred with a stirrer rod counterclockwise at 24 rotations/second. Then, remove dirt and air bubbles inside the aperture tube using the dedicated software's "Flush Aperture" function.
(2) About 30 ml of the electrolytic aqueous solution is placed in a 100 ml flat-bottom glass beaker. As a dispersant, "Contaminon N" (a 10% by mass aqueous solution of a neutral detergent for cleaning precision measuring instruments at pH 7 consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) was used as a dispersant. ) is diluted with ion-exchanged water to about 3 times the mass, and about 0.3 ml of the diluted solution is added.
(3) Prepare an ultrasonic disperser "Ultrasonic Dispension System Tetra 150" (manufactured by Nikkaki Bios Co., Ltd.) with an electrical output of 120 W and two oscillators with an oscillation frequency of 50 kHz built in with a phase shift of 180 degrees. About 3.3 l of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of Contaminon N is added to this 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 level of the electrolytic aqueous solution in the beaker is maximized.
(5) While the electrolytic aqueous solution in the beaker in (4) above is being irradiated with ultrasonic waves, about 10 mg of toner is added little by little to the electrolytic aqueous solution and dispersed. Then, the ultrasonic dispersion treatment is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water in the water tank is appropriately adjusted to 10°C or higher and 40°C or lower.
(6) Using a pipette, drop the electrolytic aqueous solution of (5) in which the toner is dispersed into the round-bottomed beaker of (1) set in the sample stand, and adjust the measured concentration to about 5%. . Then, the measurement is continued until the number of measured particles reaches 50,000.
(7) Analyze the measurement data with the dedicated software attached to the apparatus, and calculate the weight average particle size (D4). Incidentally, the weight average particle diameter (D4) is the "average diameter" on the "analysis/volume statistical value (arithmetic mean)" screen when graph/vol% is set in the dedicated software.

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to these. Examples 10-15 are reference examples. In addition, all "parts" of each material in Examples and Comparative Examples are based on mass unless otherwise specified.

[Example 1]
(Preparation step of aqueous medium 1)
To 390.0 parts of ion-exchanged water in a reaction vessel, 14.0 parts of sodium phosphate (12 hydrate, manufactured by Rasa Kogyo Co., Ltd.) was added, and the mixture was kept at 65° C. for 1.0 hour while purging with nitrogen.

T. K. Using a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), while stirring at 12000 rpm, a calcium chloride aqueous solution obtained by dissolving 9.2 parts of calcium chloride (dihydrate) in 10.0 parts of ion-exchanged water is collectively mixed. to prepare an aqueous medium containing a dispersion stabilizer. Furthermore, 10% by mass hydrochloric acid was added to the aqueous medium to adjust the pH to 6.0, and an aqueous medium 1 was obtained.

(Preparation step of polymerizable monomer composition)
・Styrene: 60.0 parts ・C.I. I. Pigment Blue 15:3: 6.5 parts The above material was placed in an attritor (manufactured by Mitsui Miike Kakoki Co., Ltd.), and further dispersed using zirconia particles with a diameter of 1.7 mm at 220 rpm for 5.0 hours, A pigment dispersion was prepared.

The following materials were added to the pigment dispersion.
・Styrene: 15.0 parts ・n-Butyl acrylate: 25.0 parts ・Divinylbenzene (crosslinking agent): 0.3 parts ・Saturated polyester resin: 4.0 parts (propylene oxide-modified bisphenol A (2 mol adduct) and terephthalic acid (molar ratio 10:12), glass transition temperature (Tg) = 68 ° C., weight average molecular weight (Mw) = 10000, molecular weight distribution (Mw / Mn) = 5.12)
Fischer-Tropsch wax (melting point 78°C): 9.0 parts K. A homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) was used to uniformly dissolve and disperse at 500 rpm to prepare a polymerizable monomer composition.

(Preparation step of organosilicon compound aqueous solution)
60.0 parts of ion-exchanged water was weighed into a reactor equipped with a stirrer and a thermometer, and the pH was adjusted to 3.0 using 10% by mass hydrochloric acid. This was heated with stirring to bring the temperature to 70°C.

Thereafter, 40.0 parts of methyltriethoxysilane was added and stirred for 2 hours to hydrolyze the organosilicon compound for the surface layer. The end point of the hydrolysis was visually confirmed by confirming that the oil and water did not separate and formed a single layer, and the organic silicon compound aqueous solution 1 was obtained by cooling.

(Granulation process)
The temperature of the aqueous medium 1 is set at 70°C, T.E. K. While maintaining the rotation speed of the homomixer at 12000 rpm, the polymerizable monomer composition was charged into the aqueous medium 1, and 9.0 parts of t-butyl peroxypivalate as a polymerization initiator was added. The mixture was granulated for 10 minutes while maintaining 12000 rpm with the stirring device.

(Polymerization process)
After the granulation step, the stirrer was changed to a propeller stirring blade, and the mixture was stirred at 150 rpm while maintaining the temperature at 70°C for 5.0 hours to polymerize, and then heated to 95°C for 2.0 hours to polymerize. A reaction was carried out to obtain a slurry of base particles.

After that, the temperature of the slurry was cooled to 60° C. and the pH was measured to be pH=5.0. While stirring was continued at 60° C., 20.0 parts of the hydrolyzate 1 of the organosilicon compound for the surface layer was added to start forming the surface layer of the toner. After holding for 30 minutes as it is, the slurry was adjusted to pH=9.0 for completion of condensation using an aqueous sodium hydroxide solution and held for an additional 300 minutes to form a surface layer.

(Washing and drying process)
After completion of the polymerization process, the obtained toner slurry is cooled, and hydrochloric acid is added to the toner slurry to adjust the pH to 1.5 or less, and the mixture is left with stirring for 1 hour and then solid-liquid separated by a pressurized filter to obtain toner. got cake.

This was reslurried with ion-exchanged water to form a dispersion again, and then subjected to solid-liquid separation with the aforementioned filter. After reslurry and solid-liquid separation were repeated until the electrical conductivity of the filtrate became 5.0 μS/cm or less, solid-liquid separation was finally performed to obtain a toner cake.

The resulting toner cake was dried with a flash jet dryer (manufactured by Seishin Enterprise Co., Ltd.).

The drying conditions were as follows: the blowing temperature was 90°C, the outlet temperature of the dryer was 40°C, and the feeding speed of the toner cake was adjusted so that the outlet temperature did not deviate from 40°C according to the moisture content of the toner cake.

In this example, the obtained toner particles 1 were used as the toner 1 without adding an external additive.

Toner 1 was confirmed by the method described above to have a surface layer containing an organosilicon polymer. Table 2 shows the physical properties of Toner 1 obtained. The evaluation method for Toner 1 is described below. Moreover, the results are shown in Table 3.

<Evaluation of developability of toner using laser beam printer>
A commercially available Canon laser beam printer "LBP7600C" modified was used.

The modifications were made by changing the gears and software of the main body of the evaluation machine so that the number of revolutions of the developing roller was twice that of the drum. A toner cartridge of LBP7600C was loaded with 40 g of toner.

(1) Evaluation under low temperature and low humidity environment (solid followability, transfer dust, halftone reproducibility, development streaks)
Under a low-temperature and low-humidity environment (15° C./10% RH), five solid images were printed on LETTER size Business 4200 paper (manufactured by XEROX, 75 g/m ² ).

Furthermore, a grid pattern with 1 cm intervals of lines with a thickness of 100 μm (the thickness of the electrostatic latent image) was output.

Furthermore, one halftone image was output.

After that, 2000 sheets of images with a printing rate of 1% were output.

After that, one halftone image was output.

All solid images, lattice pattern images, and halftone images obtained were evaluated for solid followability, transfer dust, halftone reproducibility, and development streaks.

The image density is measured by using a Macbeth reflection densitometer RD918 (manufactured by Macbeth Co.) according to the attached instruction manual and measuring the relative density of the white background portion with an image density of 0.00. and the obtained relative density was used as the value of the image density.

[Evaluation criteria]
(solid followability)
Evaluation was made on the basis of the difference between the image density at the leading edge of the first solid image and the trailing edge of the third solid image.
A: The difference between the image density at the leading edge of the first all-solid image and the image density at the trailing edge of the third all-solid image is less than 0.10. B: The image density at the leading edge of the first all-solid image and the all-solid image. The difference between the image density at the trailing edge of the third sheet and the image density is 0.10 or more and less than 0.20 C: The difference between the image density at the leading edge of the first solid image and the image density at the trailing edge of the third solid image. The difference is 0.20 or more and less than 0.30 D: The difference between the image density at the leading edge of the first solid image and the image density at the trailing edge of the third solid image is 0.30 or more and less than 0.40 E: The difference between the image density at the leading edge of the first all-solid image and the image density at the trailing edge of the third all-solid image is 0.40 or more.

(Transcription Chile)
The grid pattern image was observed using a loupe with a magnification of 25 times, and the transfer dust (phenomenon in which toner is scattered around characters and line images) was evaluated based on the following criteria.
A: Very sharp lines with almost no transfer dust B: Slight toner scattering, sharp lines C: Somewhat much toner scattering but relatively sharp lines D: Some toner scattering In many cases, the line becomes a vague shape

(Halftone reproducibility)
A halftone image (the 49th gradation counted from the solid white image when the solid white to solid black is divided into 256 gradations) is visually observed, and the halftone reproducibility of the image is evaluated according to the following criteria. evaluated based on
A: It is smooth with no feeling of coarseness.
B: Roughness is not felt so much.
C: There is a slightly coarse feeling.
D: There is a clear rough feeling.

(Development streak)
Evaluation was made by the number of vertical streaks appearing on the developing roller and on the halftone image.
A: No vertical streaks in the paper ejection direction are observed on the developing roller or on the image.
B: Five or less thin streaks in the circumferential direction are observed on both ends of the developing roller. Alternatively, a slight vertical streak in the paper discharge direction can be seen on the image. However, it is a level that can be erased by image processing.
C: 6 or more and 20 or less thin streaks in the circumferential direction are observed on both ends of the developing roller. Alternatively, several fine streaks can be seen on the image. A level that cannot be erased even with image processing.
D: 21 or more streaks were observed on the developing roller and on the image, at a level that could not be erased even by image processing.

(2) Evaluation under high temperature and high humidity environment (halftone reproducibility)
The process cartridge filled with toner was stored for 3 days in a high-temperature and high-humidity environment (35° C./80% RH). After that, five sheets of all solid images were output on LETTER size Business 4200 paper (manufactured by XEROX, 75 g/m ² ).

After that, one sheet of halftone image was output, and halftone reproducibility was evaluated according to the same evaluation criteria as in (1).

(3) Evaluation under Normal Temperature and Normal Humidity Environment (Low Temperature Fixability)
Using LBP7600C modified so that the fixing temperature can be adjusted, the fixing temperature was changed from 140° C. in increments of 5° C. under a normal temperature and normal humidity environment (25° C./50% RH) at a process speed of 300 mm/sec. For the toner to be evaluated, a solid image with a toner load of 0.40 mg/cm ² was formed on LETTER size Business 4200 paper (manufactured by XEROX, 75 g/m ² ), heated and pressed without oil, and a fixed image was obtained. formed. Using a Kimwipe (S-200, manufactured by Crecia Co., Ltd.), the fixed image is rubbed 10 times with a load of 7.35 kPa (75 g/cm ² ), and the temperature at which the image density reduction rate before and after rubbing is less than 5% is determined. The fixing temperature was taken as evaluation based on the following criteria.

For the measurement of the image density, a color reflection densitometer X-RITE 404A (manufactured by X-Rite Co.) was used to measure the relative density of the white background portion of the original with a density of 0.00 with respect to the printed image. A rate of decrease in image density was calculated.
A: Less than 150°C B: 150°C or more and less than 160°C C: 160°C or more and less than 170°C D: 170°C or more

[Examples 2, 3, 13, 14]
Toner particles 1 produced in Example 1 were externally added as shown in Table 1 to produce toners 2, 3, 13 and 14. The method of external addition is to mix 100.0 parts of the toner particles with the external additive in the number of parts shown in Table 1 using a Mitsui Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) at 3000 rpm for 15 minutes to form a toner. Obtained.

The titanium oxide fine particles in Table 1 were treated with 3,3,3-trifluoropropyltrimethoxysilane (6% by mass) and isobutyltrimethoxysilane (6% by mass), and had a BET specific surface area of 34 m ² /g. used things.

DHT-4A manufactured by Kyowa Chemical Industry Co., Ltd. was used as the hydrotalcite fine particles in Table 1.

Table 2 shows the physical properties of the obtained toner, and Table 3 shows the evaluation results.

[Examples 4 to 12, 15]
In Example 1, the type of organosilicon compound used in the "organosilicon compound aqueous solution preparation step" and the number of parts of the organosilicon compound aqueous solution 1 added in the "polymerization step" were changed as shown in Table 1. Toners 4 to 12 and Toner 15 were produced in the same manner as in Example 1 except for the above.

It was confirmed by the method described above that the obtained toner had a surface layer containing an organosilicon polymer. Table 2 shows the physical properties of the toner, and Table 3 shows the evaluation results.

[Comparative Example 1]
In Example 1, 15 parts of methyltriethoxysilane, which is an organosilicon compound, was added as a monomer in the "preparation step of the polymerizable monomer composition" instead of not performing the "organosilicon compound aqueous solution preparation step". bottom.

In addition, in the "polymerization step", after obtaining the slurry of the base particles, the organosilicon compound aqueous solution was not added, and only pH adjustment and subsequent maintenance were carried out.

Toner particles 16 were produced in the same manner as in Example 1 except for the above. The obtained toner particles 16 were used as the toner 16 as they were without external additives.

It was confirmed by the method described above that the obtained toner had a surface layer containing an organosilicon polymer. Table 2 shows the physical properties of the obtained toner, and Table 3 shows the evaluation results.

[Comparative Example 2]
In Example 1, 8 parts of methyltriethoxysilane, which is an organosilicon compound, was added as a monomer in the ``preparation step of the polymerizable monomer composition'' instead of performing the ``preparation step of the organosilicon compound aqueous solution''. .

In addition, in the "polymerization step", after obtaining the slurry of the base particles, the organosilicon compound aqueous solution was not added, and only pH adjustment and subsequent maintenance were carried out.

Toner particles 17 were produced in the same manner as in Example 1 except for the above. The obtained toner particles 17 were used as the toner 17 as they were without being externally added.

It was confirmed by the method described above that the obtained toner had a surface layer containing an organosilicon polymer. Table 2 shows the physical properties of the obtained toner, and Table 3 shows the evaluation results.

[Comparative Example 3]
In Example 1, 4 parts of the organosilicon compound methyltriethoxysilane was added as a monomer in the "preparation step of the polymerizable monomer composition" instead of not performing the "process of preparing aqueous solution of organosilicon compound". bottom.

In addition, in the "polymerization step", after obtaining the slurry of the base particles, the organosilicon compound aqueous solution was not added, and only pH adjustment and subsequent maintenance were carried out.

Toner particles 18 were produced in the same manner as in Example 1 except for the above. The obtained toner particles 18 were used as the toner 18 as they were without external additives.

It was confirmed by the method described above that the obtained toner had a surface layer containing an organosilicon polymer. Table 2 shows the physical properties of the obtained toner, and Table 3 shows the evaluation results.

[Comparative Examples 4 to 6]
Toner particles 16 produced in Comparative Example 1 were externally added as shown in Table 2 to produce Toners 19 to 21. The method of external addition is to mix 100.0 parts of the toner particles with the external additive in the number of parts shown in Table 1 using a Mitsui Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) at 3000 rpm for 15 minutes to form a toner. Obtained.

The hydrophobic silica fine particles in Table 2 were treated with silicone oil (20% by mass) and had a BET specific surface area of 170 m ² /g.

Table 2 shows the physical properties of the obtained toner, and Table 3 shows the evaluation results.

[Comparative Examples 7 and 8]
In Example 1, the "step of adjusting the organosilicon compound aqueous solution" was not performed.

In addition, in the "polymerization step", after obtaining the slurry of the base particles, the organosilicon compound aqueous solution was not added, and only pH adjustment and subsequent maintenance were carried out. Toner particles 22 were produced in the same manner as in Example 1 except for the above.

The toner particles obtained were externally added as shown in Table 1 to prepare toners 22 and 23 . The method of external addition is to mix 100.0 parts of the toner particles with the external additive in the number of parts shown in Table 2 using a Mitsui Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) at 3000 rpm for 15 minutes to form a toner. Obtained. Table 2 shows the physical properties of the obtained toner, and Table 3 shows the evaluation results.

Claims (6)

A toner having toner particles containing a colorant and a binder resin,
The toner particles have a surface layer containing an organosilicon polymer,
The force between two particles is 3.3 nN or more and 14.8 nN or less when a toner compact formed by compressing the toner with a load of 78.5 N is measured, and
A toner having a coefficient of variation of the surface potential distribution of 33 % or less in the surface potential distribution of the toner measured by a scanning probe microscope. 2. The toner according to claim 1, wherein the toner has an average absolute value of surface potential distribution of 1.0 V or more and 15.0 V or less. 2. The toner according to claim 1, wherein the toner has a force between two particles of 4.8 nN or more and 5.4 nN or less and a coefficient of variation of surface potential distribution of 18% or more and 20% or less. 4. The toner according to claim 3 , wherein the toner has an average absolute value of surface potential distribution of 2.5 V or more and 2.8 V or less. 5. The toner according to any one of claims 1 to 4 , wherein the content of the organosilicon polymer in the toner particles is 0.5% by mass or more and 5.0% by mass or less. 6. The toner according to claim 5 , wherein the organosilicon polymer is a polymer having a partial structure represented by the following formula (R ^a T3).
R ^a —SiO _3/2 (R ^a T3)
(In the formula, R ^a represents a hydrocarbon group having 1 to 6 carbon atoms, an aryl group, or a structure represented by the following formula (i) or formula (ii).

In formulas (i) and (ii), * represents a bonding site with the Si element in the R ^a T3 structure, and L in formula (ii) represents an alkylene group or an arylene group. )

Images