JP2895096B2 - Novel fluoran derivative, method for producing the same and color-forming recording material using the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel fluoran derivative having excellent applicability as a color-forming recording material. More specifically,
General formula [I] Wherein R ₁ and R ₂ represent a lower alkyl group or a cyclohexyl group, R ₃ represents a hydrogen atom or a lower alkyl group, and R ₄ represents a lower alkyl group. The present invention relates to a color recording material characterized by being contained as an active ingredient.

The compound of the present invention is industrially used as a dye, and in particular, as a coloring material, a recording material, for example,
Color appears due to pressure-sensitive recording material, heat-sensitive recording material or temperature.
It has excellent applicability to the temperature indicating material to be erased.

(Prior Art) Conventionally, compounds having the following structures are known as black color-forming colorless leuco dyes used for pressure-sensitive or heat-sensitive recording materials.

For example, a compound in which R ₃ is a methyl group, X is a phenyl group, and R ₁ and R ₂ are simultaneously an ethyl group, or R ₁ . Compounds in which R ₂ is replaced by another substituent, or compounds in which R ₃ is hydrogen and X is o-chloro or o-fluorophenyl group, or R ₁ and R ₂ are ethyl group or butyl group is there. In recent years, the types of developers for pressure-sensitive or heat-sensitive recording paper have diversified, and in addition to acidic clay or phenol resin-based developers, developers containing a salicylic acid skeleton have appeared on the market, Generally, a fluoran-based pigment tends to develop a reddish color in an acidic clay or salicylic acid-based developer and a greenish color in a phenolic resin-based developer. Therefore, usually, depending on the type of the developer, a green color dye or a red color dye is shared with the fluoran black dye to adjust the hue. In this case, the hue controlling dye is preferably a compound having a structure as similar as possible, but there is no suitable compound in practice, and a dye having a different structure is blended. This is not preferable because the behavior of the hue change often differs.

(Problems to be Solved by the Invention) An object of the present invention is to provide a novel fluoran derivative which can solve the above-mentioned problems of the conventionally known fluoran dye, and a chromogenic recording characterized by containing the derivative. Is to provide the material.

(Means for Solving the Problems) The present inventors have conducted intensive studies to solve the problems.

That is, the present invention provides a compound represented by the general formula [I]: (Wherein, R ₁ and R ₂ represent a lower alkyl group or a cyclohexyl group, R ₃ represents a hydrogen atom or a lower alkyl group, and R ₄ represents a lower alkyl group), and a color of this fluoran derivative It is a color-forming recording material contained as a chromatic material.

The diphenylamine derivative used for producing the fluoran derivative of the present invention has the following general formula [II] (Wherein, R ₃ represents a hydrogen atom or a lower alkyl group;
R ₄ and R ₅ represent a lower alkyl group, which may be the same or different), specifically, 4,4′-dimethoxy-3′-chlorodiphenylamine, 4,4′-dimethoxy- 2'-chlorodiphenylamine, 4-methoxy-4'-ethoxy-2'-chlorodiphenylamine, 4,
4'-dimethoxy-2-methyl-2'-chlorodiphenylamine, 4-ethoxy-4'-methoxy-2'-chlorodiphenylamine, 4-ethoxy-4'-butoxy-
2'-chlorodiphenylamine or 4-ethoxy-
4'-ethoxy-2-methyl-2'-chlorodiphenylamine and the like are exemplified.

Further, the ketone acid derivative used in the method of the present invention,
General formula [III] (Wherein, R ₁ and R ₂ represent a lower alkyl group or a cyclohexyl group), specifically, o- (4-dimethylamino-2-oxybenzoyl) benzoic acid, o -(4-diethylamino-2-oxybenzoyl) benzoic acid, o- (4-dibutylamino-2)
-Oxybenzoyl) benzoic acid, o- (4-methylcyclohexylamino-2-oxybenzoyl) benzoic acid or o- (4-ethylamylamino-2-oxybenzoyl) benzoic acid are exemplified. However, it is not limited to these compounds.

The amounts of these diphenylamine derivatives and ketone acid derivatives used are equimolar ratios, but slight variations in the amounts do not significantly affect the results.

The condensation reaction is performed in concentrated sulfuric acid. Sulfuric acid with a concentration of 90% or more is used, and concentrated sulfuric acid with a concentration of 96% is frequently used. The amount of concentrated sulfuric acid used is 2 to 10 times the amount of the reactants.

The reaction temperature and reaction time are preferably 50 ° C or less,
The reaction time is 24 to 48 hours, and the reaction proceeds even if the reaction time is short, but a sufficient yield cannot be obtained. Usually, the reaction is carried out while thoroughly stirring the reaction solution. After completion of the reaction, the reaction solution is poured into a large amount of ice water, mixed well, and the solid is squeezed, washed with water and pressed, then heated in dilute aqueous sodium hydroxide solution, squeezed with the desired product, washed with water and dried, and further heated with hot xylene. Recrystallize to obtain a purified product.

When the fluoran derivative represented by the general formula [I] of the present invention is used, for example, as a pressure-sensitive recording paper, it may be used in a solvent commonly used in this field, for example, an alkylbenzene (such as n-dodecylbenzene), an alkylbenzene or the like. Various solvents such as biphenyl (triethylbiphenyl, diisopropyldiphenyl, etc.), hydrogenated terphenyl, alkylnaphthalene (diisopropylnaphthalene, etc.), diarylethane (phenylxylylethane, styrenated ethylbenzene, etc.), or chlorinated paraffinic solvents Dissolve in a single or mixed solvent, and enclose the solution in microcapsules having partitions such as gelatin, melamine-aldehyde or urea-aldehyde resin, polyurethane, polyurea, polyamide, etc. by a method such as coacervation method or interfacial polymerization method. And the resulting capse The aqueous dispersion suitable binder (e.g., starch paste, latex) was coated on a suitable support with such, a pressure-sensitive recording on the paper, can be used. In this case, as a developer, a copolymer of salicylic acid and aldehydes of phenols or a metal salt thereof,
Substituted salicylic acid or a metal salt thereof (an alkyl-substituted, aryl-substituted or aralkyl-substituted form is known, for example, 3,5-di-α-phenethyl salicylic acid) or a resin obtained by condensing a substituted salicylic acid with a styrene oligomer; Examples thereof include zinc salts of alkylphenols (eg, octylphenol zinc salt), phenol-aldehyde resins (eg, novolak of p-phenylphenol), and activated clays. Further, it can be similarly used for a non-capsule type pressure-sensitive recording material not based on the capsule type.

When applied to a heat-sensitive recording material, a dye and a developer (for example, bisphenol A or a halide thereof, 4,4'-dioxydiphenyl sulfone or a halide or allylate thereof, p-oxybenzoate) Or a well-known developer for a heat-sensitive recording material such as a nuclear-substituted compound thereof, a hydroquinone monoether, a p-substituted mercapto compound, a salicylic acid derivative or a metal salt thereof, a thiourea derivative, and a metal complex of a heterocyclic compound. A binder (for example, polyvinyl alcohol or a modified product thereof, methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, gum arabic, a salt of a styrene-maleic anhydride copolymer, a copolymer of isobutylene-acrylic acid-maleic anhydride, etc.) ),
Pigments (talc, kaolin, carbonated lime, etc.), sensitizers (higher fatty acid amides, esters of aromatic carboxylic acids or sulfonic acids, aromatic or aromatic-substituted aliphatic ethers, aromatic or aromatic-substituted A generally known heat-sensitive recording material sensitizer such as an aliphatic hydrocarbon), and other additives,
It can be used as a heat-sensitive recording material by coating it on a suitable support as a fine dispersion. Of course, it can be used without problem in a system using a solvent instead of an aqueous dispersion system.

Furthermore, when used as a temperature indicating material, an appropriate phenolic substance (for example, bisphenol A), other color developing compounds and alcohols (for example, lauryl alcohol), and other known temperature sensitizing agents for this use are blended. Used as a modified composition.

In addition, the present invention can be used for all applications using leuco dyes as well as other leuco dyes.

(Effect) The novel fluoran derivative of the present invention develops a unique green to black color tone. For example, in a compound having the following structure, Compounds having a chlorine atom at the o-position of the NH group develop a dark green color with a salicylic acid-based or phenol resin-based developer and black on activated clay, but have a chlorine atom at the o-position of the methoxy group (therefore, Any compound at the m-position of the NH group) develops a clear green color.

Many commercially available dyes are salicylic acid-based compounds that develop reddish black, and the compounds of the present invention are extremely useful for toning commercially available fluoran-based dyes. On the other hand, a compound having the following structure It has a characteristic that it becomes more greenish black coloring than commercially available dyes and develops an appropriate hue with a salicylic acid-based developer.

Thus, the fluoran derivative of the present invention is a very useful compound as a dye for pressure-sensitive or heat-sensitive recording materials,
A recording material having good coloring and fading properties can be provided alone or in combination with a known fluoran dye.

(Examples) Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. In addition, "part" in the text means "part by weight".

Example 1 Synthesis of 3-diethylamino-7- (2'-chloro-4'-methoxyphenylamino) fluoran 4,4'-dimethoxy-2'-chlorodiphenylamine
5.3 parts and 6.2 parts of o- (2-oxy-4-diethylaminobenzoyl) benzoic acid were mixed with 35 parts of concentrated sulfuric acid while stirring, and the mixture was stirred at room temperature for 48 hours. Then, the mixture was discharged while being gradually stirred into a large amount of ice water, the precipitate was squeezed and pressed, washed with water, mixed with a diluted aqueous sodium hydroxide solution, and heated for about 30 minutes to remove alkali-soluble components. The solution was cooled, washed with water, dried, dissolved in hot xylene, xylene was removed from the solution, methanol was added, and the solution was left standing in a cool place for a long time to crystallize.
Dissolve in toluene, add ethanol and recrystallize, mp 138
Light colored crystals of の 140 ° C. were obtained. The elemental analysis values were as follows.

Elemental analysis (%) Calculated for CHNCl 70.65 5.16 5.32 6.37 Found 71.32 5.36 5.00 6.53 Example 2 Synthesis of 3-diethylamino-7- (3'-chloro-4'-methoxyphenylamino) fluoran Example 1 The same operation was carried out using 4,4-dimethoxy-3'-chlorodiphenylamine at a melting point of 107-109 ° C.
Was obtained. Its elemental analysis values were as follows.

Elemental analysis (%) Calculated for CHNCl 70.65 5.16 5.32 6.73 Found 70.95 5.38 5.18 6.59 Example 3 Synthesis of 3-dibutylamino-7- (2'-chloro-4'-methoxyphenylamino) fluoran Example The same procedure was followed using o- (2-oxy-4-dibutylaminobenzoyl) benzoic acid in 1
Crystals of 135-137 ° C. were obtained.

Example 4 [Evaluation as pressure-sensitive recording paper] 1) Preparation of upper (CB) sheet and lower (CF) sheet (1) CB sheet 10% aqueous solution of ethylene-maleic anhydride copolymer 100
And 240 parts of water, adjusted to pH = 4.0 with a 10% aqueous solution of sodium hydroxide, and mixed with 200 parts of a phenylxylylethane solution in which 5% by weight of a dye to be evaluated is dissolved. 60 parts of a 50% aqueous solution of methylol melamine (“Euramine T-30” manufactured by Mitsui Toatsu Chemicals, Inc.) was added, and the mixture was kept at 55 ° C. for 3 hours with stirring to give an average particle size of 5.0.
μ of microcapsule dispersion liquid was obtained. 20 parts of flour starch granules, 20 parts of 20% oxidized starch paste and 116 parts of water are added to 100 parts of the microcapsule solution, stirred and dispersed, and applied to a paper having a basis weight of 40 g / m ^{2 at} a solid amount of 5 g / m ² . Coating was performed to obtain a CB sheet.

(2) CF sheet (A) A zinc salt of a resin obtained by condensation of α-phenethyl group-substituted salicylic acid and a styrene oligomer is atomized by a sand grinding mill in water in the presence of a small amount of a polymer anionic surfactant, An aqueous suspension having a solid content of 40% by weight was obtained. Using this aqueous suspension, an aqueous paint having the following composition (solid content 30%)
Was prepared and coated on a high-quality paper having a basis weight of 40 g / m ^{2 so} that the dry coating amount was 5.5 g / m ² to prepare a CF sheet (A).

Composition of water-based paint Solid parts by weight Soft calcium carbonate 100 Developer 20 Adhesive Oxidized starch 8 Synthetic latex 8 CF sheet (B) Using p-phenylphenol-formaldehyde co-condensation resin instead of salicylic acid resin in (A) In the same way
A CF sheet (B) was prepared.

2) Performance evaluation of colored products (1) Coloring speed and density (implemented in a room at a constant temperature and humidity of 20 ° C and 65% RH) An electronic typewriter with both coated surfaces of CF sheet and CB sheet facing each other and overlapping The color was developed by pressing. The color density was measured at two points, one minute and 30 seconds after keying and 24 hours after keying, and displayed as a Y value.

(2) Lightfastness of Colored Image The CF sheet colored by the method of (1) was exposed for 2 hours and 4 hours with a carbon arc fade ometer (manufactured by Suga Test Instruments Co., Ltd.), and the reflectance after irradiation was Δ-. It was measured with an 80 color difference meter (manufactured by Nippon Denshoku Co., Ltd.) and indicated by Y value. The lower the Y value and the smaller the difference Δ between the values before and after the test, the less the fading due to light. Also, the lower the Y value, the higher the image density.

For CF sheet (B), compound 1 was green in hue, compound 2 was bright green, and for CF paper using commercially available activated clay, compound 1 was black and hue was dark green. .

Example 5 [Preparation of thermosensitive recording material] A thermosensitive recording material was prepared according to the following formulation.

Dye Dispersion Composition Dye (No. 1) 6 parts 10% aqueous polyvinyl alcohol solution 6 parts Water 10 parts The mixture having the above composition was finely divided into 3 μm particles by a sand mill to obtain a dispersion liquid. On the other hand, a zinc salt of a condensate of phenethylated salicylic acid and a styrene oligomer was dispersed in the same manner as the dye dispersion to obtain a developer dispersion. Then, 50 parts of an aqueous dispersion of 60% carbonated lime, 20 parts of a pigment dispersion, 70 parts of a developer dispersion, 20 parts of an aqueous dispersion of zinc stearate 20%, 20 parts of an aqueous dispersion of β-naphthyl benzoate 20 parts, 10 parts % Polyvinyl alcohol aqueous solution 100 parts, patatin wax 30% aqueous dispersion 10 parts and water 50 parts, and dry coating amount is 50 g / m ² on high quality paper.
Coating was performed so as to be 6 g / m ² to obtain a thermosensitive recording paper. Performs solid black color development with a commercially available facsimile machine, pure hue black, color density
A record of 1.26 was obtained. The light resistance and oil resistance of the color image were excellent.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiro Yamaguchi 1-1-13-24 Zaimiza, Kamakura City, Kanagawa Prefecture (56) References JP-A-54-109454 (JP, A) JP-A-60-219261 (JP, A) JP-A-60-105680 (JP, A) JP-B-51-22415 (JP, B2) JP-B-47-29663 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) ) B41M 5/12 C07D 493/10 C09B 11/28

Claims (2)

(57) [Claims] 1. A compound of the general formula [I] (Wherein, R ₁ and R ₂ represent a lower alkyl group or a cyclohexyl group, R ₃ represents a hydrogen atom or a lower alkyl group, and R ₄ represents a lower alkyl group). 2. A chromogenic recording material comprising the novel fluoran derivative represented by the general formula [I] according to claim 1 as a chromogenic chromogen.