JP2854020B2 - Novel fluoran derivatives and coloring materials containing 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 are a lower alkyl group or a cyclohexyl group, R ₃ is a hydrogen atom or a lower alkyl group, and X is a phenyl having three or more substituents, at least one of which is a halogen atom.) The present invention also relates to a novel fluoran derivative represented by the following formula: and a color-forming recording material comprising this derivative as a color-forming chromogen.

The compound of the present invention is mainly used industrially as a dye, and particularly as a coloring material, a recording material, for example, a pressure-sensitive recording material, a heat-sensitive recording material, or a temperature-indicating color that appears and disappears depending on temperature. It has excellent applicability to a recording material, such as a material, which forms a color by reacting a color-forming dye with an electron-accepting compound.

(Prior Art) Conventionally, various compounds are known as a fluoran derivative, but the fluoran derivative defined by the general formula [I] is not yet known. That is, in the general formula [I], a compound wherein X is a phenyl group having at least three substituents in which at least one is a chlorine atom and the other is a chlorine atom or a methyl group is not known.

On the other hand, in the general formula [I], a compound in which R ₃ is a methyl group, X is a phenyl group, and R ₁ and R ₂ are variously changed is well known as a black-coloring fluoran dye and is commercially available.

However, these compounds are not pure black, though they have black coloring properties, and are blended with other dyes in accordance with the type and use of the developer, and are used for practical use. However, in practical use, a coloring recording material made by mixing dyes having different structures has various inconveniences, for example, the color tone changes during coloring and the hue immediately after coloring does not match the hue after a long time has elapsed. Alternatively, there is a disadvantage that the hue at the time of fading does not match the hue at the time of color development, which causes inconvenience such as unsightlyness.

(Problems to be Solved by the Invention) An object of the present invention is to provide a novel fluoran derivative, and in particular, a fluoran derivative which is blended with itself or a black fluoran dye to form a black fluoran derivative. An object of the present invention is to provide a novel fluoran derivative which has excellent applicability to a material, has little color change at the time of color development, and has little color change at the time of fading of a color image. Another object of the present invention is to provide a color recording material containing the compound.

(Means for Solving the Problems) The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, It was found that a compound having a color hue from dark green to reddish black can be obtained only by a combination of a methyl group, an alkoxy group and a halogen atom for Y, and completed the present invention.

That is, the present invention provides a compound represented by the general formula [I]: (Wherein R ₁ and R ₂ are a lower alkyl group or a cyclohexyl group, R ₃ is a hydrogen atom or a lower alkyl group, X is
A phenyl group having at least one chlorine atom and the other being a chlorine atom or a methyl group and having three or more substituents), a color development containing this compound as a chromogenic chromogen. It is a property recording material.

The compound of the present invention is defined by the above-mentioned general formula [I], and is specifically exemplified in Examples described later.

The compound of the present invention is a compound of the formula [I], wherein X is 3
And at least one substituent is a phenyl group having a substituent in which at least one is a chlorine atom and the other is a chlorine atom or a methyl group.

The fluoran derivatives represented by these general formulas [I] have not been known so far.

The compound of the present invention, which is a fluoran derivative represented by the general formula [I], that is, a compound in which the phenyl group X is in the above defined range has similar properties, and therefore, even if two or more kinds are blended. Inconvenient change in color tone at the time of coloring or fading hardly occurs. Of course, depending on the purpose, they may be used alone, or various fluoran-based leuco dyes may be mixed and used as compounding dyes.

Mixing two or more of the compounds of the present invention according to a desired color tone is advantageous in that superior performance can be obtained from structural similarity as compared with compounds having other structures. It is.

A method for synthesizing the fluoran derivative of the general formula [I] is obtained by condensing a diphenylamine derivative of the general formula [II] and a ketone acid derivative of the general formula [III] as follows.

That is, the general formula [II] (Wherein R ₄ is a lower alkyl group, benzene nucleus A has a lower alkyl group, and benzene nucleus B is at least one of which is a chlorine atom and at least three of which are chlorine atoms or methyl groups. And a diphenylamine derivative represented by the general formula [III]: (Wherein R ₁ and R ₂ have the same meanings as in formula [I]) in concentrated sulfuric acid at 50 ° C.
It can be produced by condensation below.

Examples of the diphenylamine derivative of the general formula [II] used in this method include, for example, 2,4,5-trichloro-
4'-methoxydiphenylamine, 3,4,5-trichloro-4'-methoxydiphenylamine, 2,4-dichloro-
5-methyl-4'-methoxydiphenylamine, 2,5-
Dichloro-4-methyl-4'-methoxydiphenylamine, 3,4-dichloro-6-methyl-4'-methoxydiphenylamine, 3,4-dichloro-2-methyl-4'-methoxydiphenylamine, 3,5-dichloro- 4-methyl-4'-methoxydiphenylamine, 3,4-dichloro-
5-methyl-4'-methoxydiphenylamine, 2,4-
Dichloro-6-methyl-4'-methoxydiphenylamine, 4-chloro-2,5-dimethyl-4'-methoxydiphenylamine, 4-chloro-2,4-dimethyl-4'-methoxydiphenylamine, 2-chloro-4, 5-dimethyl-4'-methoxydiphenylamine, 2-chloro-4,6
-Dimethyl-4'-methoxydiphenylamine, 2,4-
Dichloro-5,2'-dimethyl-4'methoxydiphenylamine, 3,4-dichloro-6,2'-dimethyl-4'-methoxydiphenylamine, 2,5-dichloro-4,2'-dimethyl-4'methoxydiphenylamine , 3,4-dichloro-
6,2'-dimethyl-4'-methoxydiphenylamine,
4-chloro-3,5,2'-trimethyl-4'-methoxyzinphenylamine, 4-chloro-2,5,2'-trimethyl-4'-methoxydiphenylamine, 2-chloro-4,6,
2'-trimethyl-4'-methoxydiphenylamine,
2-chloro-4,5,2'-trimethyl-4'-methoxydiphenylamine and the like.

These diphenylamine derivatives can be produced, for example, by reacting a brominated phenol ether derivative with an acylanilide derivative in halogenated benzene to produce an acyldiphenylamide derivative, followed by hydrolysis.

As the bromophenol ether derivative used for producing these compounds, specifically, for example, 4
-Bromoanisole, 4-bromo-3-methylanisole, 4-bromo-2-methylanisole, 4-bromo-
Examples thereof include 3-chloroanisole and 4-bromo-2-chloroanisole.

The acylanilide derivative as one of the raw materials is specifically, for example, 2,4,5-trichloroacetanilide,
2,4,6-trichloroacetanilide, 2,3,4-trichloroacetanilide, 3,4,5-trichloroacetanilide,
2,4-dichloro-5-methylacetanilide, 2,5-dichloro-4-methylacetanilide, 3,4-dichloro-2
-Methylacetanilide, 3,5-dichloro-4-methylacetanilide, 3,4-dichloro-5-methylacetanilide, 2,4-dichloro-6-methylacetanilide,
4-chloro-2,5-dimethylacetanilide, 4-chloro-3,5-dimethylacetanilide, 4-chloro-2,6-
Examples thereof include dimethylacetanilide, 2-chloro-4,6-dimethylacetanilide, 2-chloro-4,5-dimethylacetanilide, and corresponding compounds in which the acetyl group of these compounds is a formyl group, a propionyl group, or a butyryl group.

The reaction between the bromophenol ether derivative and the acylanilide derivative is carried out as follows.

The amount of these derivatives used is preferably in the range of 1 to 2 molar ratio of the bromophenol ether derivative to the acylanilide derivative. If the molar ratio is less than 1, the yield is low. No further improvement in yield can be expected, and it is only difficult to recover the raw materials.

The reaction is carried out in a reaction solvent such as ortho-dichlorobenzene or trichlorobenzene. In the absence of a solvent, a large amount of resinous products are generated, and in a solvent such as xylene, the reaction is slow and there are many undesirable by-products of the resinous substance.

The reaction temperature is preferably around 180 ° C., and when using ortho-dichlorobenzene as the reaction solvent, the boiling point is suitable.

It is also effective to use potassium carbonate as a debrominating agent and simultaneously add a small amount of metallic copper or copper salt as a catalyst in the reaction solution.

The reaction time is suitably in the range of 6 to 12 hours. If the reaction time is shorter than this, the reaction is insufficient. Even if the reaction time is longer, the yield is not particularly improved.

The above reaction produces an acyldiphenylamide derivative.

The reaction solvent and unreacted substances are removed from the reaction product solution by distillation to obtain an acyldiphenylamide derivative.

This acyl diphenylamide derivative is carried out in an organic solvent miscible with water such as ethanol or / and in a water solvent using caustic alkali, particularly potassium hydroxide. Usually, the diphenylamine derivative used as a raw material of the present invention can be produced by hydrolysis with caustic potash in ethanol for 15 to 20 hours, or by heating to 120 ° C. with a water solvent in an autoclave.

In addition, the general formula [III] used in the production method of the present invention
Examples of the ketone acid derivative represented by the formula: o- (2-
Oxy-4-diethylaminobenzoyl) benzoic acid, o
-(2-oxy-4-di-n-butylaminobenzoyl) benzoic acid, o- (2-oxy-4-methylhexylaminobenzoyl) benzoic acid, o- (2-oxy-4-
Ethylbutylaminobenzoyl) benzoic acid or o-
(2-oxy-4-ethylpentylaminobenzoyl)
Benzoic acid and the like.

The reaction between the diphenylamine derivative represented by the general formula [II] and the ketone acid derivative represented by the general formula [III] is carried out with the use amounts of both compounds being substantially equimolar.
However, slight fluctuations in the quantitative ratio do not significantly affect the results.

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

The reaction time is suitably about 10 to 48 hours. The reaction proceeds even for a short time of 10 hours or less, but the yield may be insufficient. Usually, the reaction is carried out with sufficient stirring.

After completion of the reaction, the reaction solution is discharged into a large amount of ice water, the precipitated solid is separated, washed with water and pressed, and then heated in a diluted aqueous sodium hydroxide solution to remove coloring impurities. Next, the object is crushed, washed with water, pressed and dried. This is purified by an appropriate method to obtain the fluoran derivative of the present invention.

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 by coacervation method, interfacial polymerization method, etc. Of the obtained capsule The dispersion suitable binder (e.g., Shingarikonori, latex) was coated on a suitable support with such as pressure-sensitive recording on the sheet and none, can be used. In this case, as the color developer, a copolymer of salicylic acid and an aldehyde of phenols or a metal salt thereof, a substituted salicylic acid or a metal salt thereof (alkyl-substituted, aryl-substituted or aralkyl-substituted products) are known.
For example, 3,5-di-α-phenethyl salicylic acid or a resin obtained by condensing a substituted salicylic acid with a styrene oligomer, a zinc salt of an alkylphenol (eg, octylphenol zinc salt), or a phenol-aldehyde resin (eg, p-phenylphenol) Novolak) or activated clay. 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, it is possible to use the leuco dye in the same manner as other leuco dyes.

(Examples) Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the scope shown in these examples.

 In addition, "part" in the text means "part by weight".

Example 1 Synthesis of 3-dimethylamino-7- (2 ', 4', 5'-trichloroanilino) fluoran 6.1 parts of 2,4,5-trichloro-4'-methoxydiphenylamine, o- (2- 6.2 g of oxy-4-diethylaminobenzoyl) benzoic acid is mixed with 35 parts of concentrated sulfuric acid while stirring, and the mixture is stirred at room temperature for 48 hours. Then slowly add to a large amount of ice water while stirring and stir well. Then, squeeze, squeeze, wash with water, mix with diluted caustic soda aqueous solution, about 30
Heat for a minute to remove the alkali soluble components. Cool, dry, wash and dry, recrystallize from hot xylene, about 50%
The title product was obtained with a yield of. Its melting point is 216.5 ~ 218.5 ℃
And the elemental analysis values were as follows:

Elemental analysis ratio (%) Calculated value of CHNCl 63.67 4.10 4.95 18.80 Found value 64.07 4.12 4.74 18.58 Example 2 [3-Diethylamino-7- (4'-chloro-2 ', 5'
Synthesis of -dimethylanilino) fluoran] In Example 1, 5.0 g of 4-chloro-2,5-dimethyl-4'-methoxydiphenylamine was used instead of 2,4,5-trichloro-4'-methoxydiphenylamine. The reaction was carried out in the same manner to obtain the desired product in a yield of about 50%. In this case, since the target substance was easily dissolved in the solvent, the hot xylene solution was concentrated, and methanol was added thereto to cause cooling crystallization. Melting point 190
At 192192 ° C. the elemental analysis was as follows:

Elemental analysis value (%) Calculated value for CHNCl 73.20 5.57 5.34 6.75 Found value 72.95 5.37 5.19 7.05 Example 3 [Other compounds] Various compounds were synthesized in the same manner as in Example 1. The structures of the compounds and their melting points are shown in the table below.

In the following table, the structure is obtained by changing X in the following formula.

The elemental analysis values of the compounds Nos. 4, 5 and 8 are shown below.

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) Same as above except that salicylic acid resin of (A) is replaced with p-phenylphenol-formaldehyde co-condensation resin To
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 reaction rate 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.

3) Evaluation for CF paper (A) The results for CF paper (B) tend to be similar,
Taking Compound 1 as an example, the hue is reddish black and the light resistance is slightly lowered. Further, the activated clay is used as a color developer to develop a dark red color on commercial copy paper.

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

Dye Dispersion Composition Dye (No. 5) 6 parts 10% aqueous solution of polyvinyl alcohol 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 styrenoligomer was dispersed in the same manner as the dye dispersion to obtain a developer dispersion. Then, 50 parts of a 60% aqueous solution of carbonated lime, 20 parts of a pigment dispersion, 70 parts of a developer dispersion, 20 parts of a 20% aqueous salt of zinc stearate, 20 parts of a 20% aqueous dispersion of β-naphthyl benzoate, 10 parts % Polyvinyl alcohol aqueous solution 100 parts, paraffin wax 30% aqueous dispersion 10 parts and water 50 parts, and dry coating weight 6 g on high quality paper with a basis weight of 50 g / m ²
/ m ² to obtain a thermosensitive recording paper. Perform solid black color development with a commercially available facsimile machine, pure hue black, color density 1.
26 records were obtained. The light resistance and oil resistance of the color image were excellent.

Comparative Example A pressure-sensitive recording paper was prepared in the same manner as in Example 4 using the following known fluoran compound, and the performance of a color-developed product was evaluated.

 The results are shown in the following table.

(A) 3-N, N-diethylamino-7- (2 ', 3', 4 '
-(Trifluoroanilino) fluoran, (b) 3-N, N-diethylamino-7- (2'-methyl-5'-fluoroanilino) fluoran, (c) 3-N, N-diethylamino-7- ( 2'-chloro-4'-fluoroanilino) fluoran, (d) 3-N, N-diethylamino-7- (4'-chloroanilino) fluoran, (e) 3-N, N-diethylamino-7- (3 ', 5'-Dichloroanilino) fluoran.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiro Yamaguchi 1-1-13-24 Zaimiza, Kamakura City, Kanagawa Prefecture (56) References JP-A-61-81463 (JP, A) JP-A-58-65754 (JP, A) JP-A-53-25106 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C09B 11/28 B41M 5/124-5/165 CA (STN)

Claims (2)

(57) [Claims] (1) General formula [I] (Wherein R ₁ and R ₂ are a lower alkyl group or a cyclohexyl group, R ₃ is a hydrogen atom or a lower alkyl group, X is
At least one is a chlorine atom, and the other is a chlorine atom or a methyl group, which represents a phenyl group having three or more substituents). 2. A chromogenic recording material comprising the novel fluoran derivative represented by the general formula [I] according to claim 1 as a chromogenic chromogen.