JPH0393589A - Recording material - Google Patents

Abstract

PURPOSE:To improve color forming properties by containing a fluorane derivative containing an alkylamino group having an acyloxy group at a predetermined position thereof. CONSTITUTION:An acyloxy group to be used is represented by formula (wherein R is a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an aryloxy group, a heterocyclic ring residue or one of these groups having a subatituent and X is an oxygen atom or a sulfur atom). In order to obtain a black hue, a fluorane derivative is pref. substituted with amino groups at both of the 2- and 6-positions thereof. The 5- and 7-positions thereof are pref. a hydrogen atom from the aspect of a developed color hue and developed color density.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a recording material, and particularly to a recording material with improved color development. (Prior art) Recording materials using electron-donating colorless dyes and electron-accepting compounds include pressure-sensitive paper, thermal paper, and photosensitive pressure-sensitive paper. It is already well known as electrically conductive thermal recording paper, thermal transfer paper, etc. For example, British Patent No. 2140449, U.S. Patent No. 4480052, U.S. Patent No. 4436920, Japanese Patent Publication No. 60-23992, Japanese Unexamined Patent Publication No. 57
-17.9836, 60-123556, 60-
I am familiar with 123557 etc. ．． In recent years, research has been conducted to improve properties of recording materials, such as (1) color density and color sensitivity, and (2) fastness of color formers.

The present inventors have investigated the oil solubility, water solubility, partition coefficient, pKa, polarity of substituents, position of substituents, and crystallinity when used in combination for each of the electron-donating colorless dye and electron-accepting compound. Focusing on characteristics such as changes in solubility, we have pursued the development of good materials for recording materials and recording materials.

(Object of the invention) Therefore, the object of the present invention is to provide a recording material using a material that has good color development and satisfies other requirements. (Structure of the invention) Object of the invention - This was achieved by a recording material containing a fluoran salt conductor having an alkylamino group with an acyloxy group at the 6-position as an electron-donating colorless dye.The acyloxy group in the present invention is represented by the following formula R- It is represented by C-X- 11 0 .

(In the formula, R represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an aryloxy group, a peterocyclic residue, or a substituent-containing group thereof, and X represents an oxygen atom or a sulfur group. (Represents an atom.) In the fluoran derivative according to the present invention, in order to obtain a black hue, it is preferable that both the 2-position and the 6-position are substituted with an amino group. The 5th and 7th positions are preferably hydrogen atoms from the viewpoint of color development hue and color density.

Among these, those represented by the following general formula (1) are preferred. (In the formula, RI and R represent an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a hydrogen atom; R represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom; R
4 is a hydrogen atom, an alkyl group, an alkenyl group, an arvinyl group, an aryl group, an alkoxy group, an aryl group,
Arylthio group, halogen atom, substituted amino group, cyano group, ditro group, acyl group, trihalomethyl group, sulfamoyl group, R and X are the aforementioned groups, illA is an aromatic ring that may contain a heteroatom , n represents an integer from 1 to 10. The xanthene ring or IIA may have a plurality of the same or different substituents, and in this case, the substituents represent an alkoxy group, a halogen atom, or a nitro group. ) In the above general formula (I), the group represented by R1 further includes an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, a halogen atom, a substituted amino group, and a cyano group. , a nitro group, an acyl group, a trihalomethyl group, a sulfamoyl group, a heterocyclic residue, etc. These substituents may further have a substituent. R, is -C
nH, nOCmH2,, YZ% (n is an integer from 2 to 1O, m is an integer from 1 to 5, Y and Z are hydrogen atoms, alkyl groups, alkenyl groups, arvinyl groups, aryl groups, alkoxy groups, aryloxy groups,
It represents an alkylthio group, a halogen atom, a substituted amino group, a cyano group, a ditro group, an acyl group, a trihalomethyl group, a sulfamoyl group, a heterocyclic residue, etc. ) is preferred.

As R, particularly preferred are a methyl group, an ethyl group, a proyl group, a butyl group, and the like.

In the above formula, the group represented by R is preferably an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, or a halogen atom, particularly a methyl group, an ethyl group, a methoxy group, a methoxymethyl group, a methylthio group, or a chlorine atom. preferable.

In the above formula, the group represented by R is a hydrogen atom, and has 1 to 1 carbon atoms.
8 is preferable, and a hydrogen atom and a methyl group are particularly preferable. When R3 is a hydrogen atom, R4 is preferably a hydrogen atom or an alwyl group having 1 to 8 carbon atoms. R,
When is a methyl group, R is preferably a trifluoromethyl group, a ditro group, a cyano group, a sulfamoyl group, or the like.

In the above formula, the group represented by R is preferably an alkyl group or an aryl group, and these may have a substituent. Substituents include saturated or unsaturated alkyl groups, cycloalkyl groups, aryl groups, hydroxy groups, alkoxy groups, alkylthio groups, aryloxy groups, arylthio groups, halogen atoms, dialkylami7 groups, carbonyl groups, carboxyl groups, carpoxyl groups. A carbamoyl group, an alkoxycarbonyl group, an acyl group, a cyano group, a nitro group, a sulfonyl group, an incyanato group, a heterocyclic residue, and the like are preferred.

These substituents may further have similar substituents, or may have several phenolic compounds or compounds having carbonyl groups in the molecule via substituents.

In particular, R includes a methyl group, a benzyl group, a phenoxymethyl group, anisyl group, a cyclohexyl group, a phenyl group,
Methylphenyl group, methoxyphenyl group, phenoxyphenyl group, hydroxyphenyl group, chlorophenyl group,
A fluorophenyl group, a siethylaminophenyl group, etc. are preferred.

In the above formula, ring 8 is preferably a benzene ring, a naphthalene ring, a pyridine ring, a birimidazine ring, an indole ring, etc., and a benzene ring is particularly preferred.

When ring 8 is substituted with the same or different substituents,
Substituents include halogen atoms, nitro groups, cyano groups,
An alkoxy group is preferable, and a chlorine atom and a fluorine atom are particularly preferable.

Especially in the above formula. R, is an alkyl group having 1 to 6 carbon atoms +
R2 is an alkyl group having 1 to 4 carbon atoms. R, and R
, is a hydrogen atom, Rs is a phenyl group, methoxyphenyl group, or phenoxymethyl group, and n is preferably 2 or 3. Specific examples of fluoran derivatives according to the present invention are shown below, but the present invention is not limited thereto. (1) 2-anilino 3-methyl-6-N-ethyl-N- (2-acetoxyethyl)aminofluorane (2) 2-anilino 3-methyl-6-N-ethyl-N- (3-penzoyl) iciprovir) aminofluorane [3) 2-anilino 3-methyl-6-N-ethyl-N
- (3- (4-Methoxybenzoyloxy>probyl) aminofluorane (4) 2-anilino 3-chloro-6-N-ethyl-N
- (3- (2-allyloxybenzoyloxy)propyl]aminofluorane (5) 2-anilino 3-methyl-6-N-ethyl-N
-(3- (4-methylbenzoyloxy〉provil)
Aminofluorane (6) 2-anilino-3-methyl-6-N-ethyl-N
-(3- (phenoxyacetyloxy)propyl]aminofluorane (7) 2-anilino 3-methyl-6-N-ethyl-N
- (3- (2-naphthoyloxy>propyl) aminofluorane (8) 2-(2-chlorophenylamino)-6-N-methyl-N- [3- (4-phenylpenzoyloxy)propyl] Aminofluorane (9) 2-anilino 3-methyl-6-N-butyl-N
- (3- (phenylacetyloxy)phenolicy)
Provil] Aminofluorane α02-(4-ethylphenylami/〉-3-methyl-
6-N-ethyl-N- (2-<3-methylbenzoyloxy>ethyl]aminofluorane Ql)2-N-
Methyl-N-(3-}lifluoromethylphenyl)amino-6-N-ethyl-N-(3-penzoyloxyprobyl>aminofluorane Q21 2-N-methyl-N-(2,4-dimethylamino)-6- N-ethyl-N- [:3- (3-methoxybenzoyloxy>propyl]aminofluorane α3 2-anilino 3-methyl-6-N-ethyl-N
- (2-(3-pyrididoyloxy)ethyl)aminofluorane α4) 2-anilino3-methyl-6-N-amyl-N-(3-(2-furoyloxy)probyl)aminofluorane α512- Anilino 3-methyl-6-N-methyl-N
- (3- (4-Ethoxylponyloxybenzoyloxypropylene)aminofluorane α14) 2
-anilino3-methyl-6-N-ethyl-N- (3
-(2-Carboxybenzoyloxy)probyl]aminofluorane and the like. The electron-donating colorless dye used in the present invention is a conventionally known triphenylmethane phthalide compound. Fluoran compounds. Phenothiazine compounds. Indolylphthalide compounds, leucoauramine compounds, rhodamine lactam compounds, triphenylmethane compounds. Triazene compounds. It can be used in combination with various compounds such as spiropyran compounds and fluorene compounds. Specific examples of phthalides are given in U.S. Reissue Patent Specification No. 23.0.
No. 24. U.S. Patent No. 3.491.1l1. Same No. 3.491.112. No. 3,491.116 and No. 3.509.174. Specific examples of fluorans are U.S. Patent Specifications Nos. 3.624.107 and 3.62.
7.787. Same No. 3.641.011, Same No. 3.4
No. 62.828. 3.681,390, 3.
No. 920.510. Same No. 3.959.571. Specific examples of subirodipyrans are given in U.S. Patent Specification No. 3.97.1.
No. 808. Pyridine and pyrazine compounds are described in U.S. Patent No. 3.775.424. Same No. 3.853,
No. 869. No. 4,246.318. Specific examples of fluorene compounds are described in Japanese Patent Application No. 61-240989. Examples of electron-accepting compounds used in the recording material of the present invention include phenol derivatives. Salicylic acid derivatives, metal salts of aromatic carboxylic acids, acid clay. Bentonite, novolac resin. Metal processing novolak resin.
Examples include metal complexes. Examples of these can be found in Special Publication No. 40-9309. Japanese Patent Publication No. 45-14039, Japanese Patent Publication No. 140483-1983. JP-A-48-51510, JP-A-57-210886, JP-A-58-87089. Japanese Patent Publication No. 59-11286
No. 60-176795. Japanese Patent Publication No. 61-959
It is described in No. 88, etc. Examples of electron-accepting compounds include bisphenol A. 2
．． 2-bis(3-methyl-4-hydroxyphenyl)propane. 2.2-bis(4-hydroxyphenyl)butane. 1.1-bis(4-hydroxyphenyl)butane, 1.1-bis(4-hydroxyphenyl)-2-ethylhexane, 1.1-bis(3-chloro4-hydroxyphenyl)-2- Ethylbutane, bis(3-allyl-4-hydrocyphenyl)sulfone.1,7-bis(4
-Hydroxyphenylthio)-3,5-dioxahebutane. (4-Hydroxyphenyl)-(4-improboxyphenyl)sulfone. 4-hydroxybenzoic acid benzyl ester, 2.4 dihydroxybenzoic acid monoβ-phenoxyethyl ester. 2,4 dihydroxybenzoic acid monoalpha
-Methyl-β-(3-methoxyphenoxy)ethyl ester. Examples include 1.3-bis(4-hydroxyphenyl)propane, 2-(2.4dihydroxyphenyl)-2-phenylpropane, 3.5-bis(α-methylbenzyl)zinc salicylate, etc. When the recording material of the invention is used for thermal paper, please refer to JP-A-62-144.989.
It follows the pattern as described in the specification of Japanese Patent Application No. 62-244.883. Specifically, the electron-donating colorless dye and the electron-accepting compound are 10μ or less in the separation medium. It is preferably used after being crushed and dispersed to a particle size of 3μ or less. As a dispersion medium. Generally, an aqueous polymer solution with a concentration of about 0.5 to 10% is used and dispersion is carried out using a ball mill. Sand mill. Horizontal sand mill. Attritor. This is done using a colloidal mill, etc. The ratio of the electron-donating colorless dye to the electron-accepting compound used is preferably between 1=10 and 1:1, and particularly preferably between 1:5 and 2:3. At this time, a thermofusible substance can be included in the thermosensitive coloring layer in order to improve thermal responsiveness. Representative thermofusible substances include aromatic ethers, thioethers, esters, and/or aliphatic amides or ureides.

Examples of these can be found in Japanese Patent Application Laid-Open No. 58-57989, . 58-8
7094, No. 61-58789, No. 62-
No. 109681, No. 62-132674, No. 63-1
No. 51478, No. 63-235961, Patent Application No. 1-4
No. 447, No. 1-37070, etc.

Examples of thermofusible substances include fluoromethylbiphenyl ether, penzyloxynaphthalene, penzylbiphenyl, 1,2-diphenothiethane, 1,2-di-m-}lyluioethane, and l-phenoxy. 2-p-methoxyphenoxyethane, 1-p-methoxyphenoxy-210-chlorophenoxyethane, 1.2-p-fluorophenoxyethane, 1.3-p-methoxy Phenoxypropane, 1,2-p-methoxyphenoxypropane, l-phenoxy-2-p-methoxyphenoxypropane, 1-p-methoxyphenoxyethoxy-2-p
-methoxyphenoxyethane, 1,2-di-p-methoxyphenylthioethane, p-methoxybenzyloxytolylmethane, (4-methoxybenzyloxy)-(3-
Methyl-4-chlorophenyl>methane, p-chlorobenzyloxy-p-ethyphenylmethane, and the like.

．． These are used in finely dispersed form at the same time as an electron-donating colorless dye or at the same time as an electron-accepting compound. Amount of these usage.
For electron-accepting compounds. It is added at a weight ratio of 20% or more and 300% or less. Particularly preferred is 40% or more and 150% or less. The coating liquid obtained in this way has: Furthermore, additives are added as necessary to meet various requirements. An example of an additive is an inorganic pigment in the binder to prevent the recording head from becoming dirty during recording. Oil-absorbing substances such as polyurea fillers are dispersed. Furthermore, fatty acids are added to improve mold release properties from the head. Metallic soaps are added. Therefore, in general. In addition to electron-donating colorless dyes and electron-accepting compounds that directly contribute to color development, there are also thermofusible substances and pigments. wax. Antistatic agent, ultraviolet absorber. Antifoaming agent, conductive agent. Additives such as fluorescent dyes and surfactants are coated onto the support. Recording materials will be compromised. Furthermore, a protective layer may be provided on the surface of the heat-sensitive recording layer if necessary. Add a protective layer as necessary. Two or more layers may be laminated. Also, to correct the curl balance of the support. A coating liquid similar to a protective layer may be applied to the back side to improve chemical resistance from the back side. You can also apply adhesive to the back side and string release paper together to form a label. Usually, electron-donating colorless dyes and electron-accepting compounds are. It is dispersed and applied in a binder. Water-soluble binders are generally used, such as polyvinyl alcohol, hydroethyl cellulose, and hydroxybrobyl cellulose. Shrimp chlorohydrin modified polyamide, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, imbutylene-maleic anhydride copolymer. Polyacrylic acid. Polyacrylic acid amide.
Methylol-modified polyacrylamide. Denbun derivative.
Examples include casein and gelatin. Water-resisting agents are also added to these binders to make them water-resistant.
Emulsions of hydrophobic polymers, specifically. Styrene-butadiene rubber latex, acrylic resin emulsion, etc. can also be added. ．． The resulting heat-sensitive coating liquid has high-quality paper and an undercoat layer. It is applied to high-quality paper, synthetic paper, plastic film, etc. In this case, it is particularly preferable to use a support having a smoothness defined by JIS-8119 of 500 seconds or more, particularly 800 seconds or more, from the viewpoint of dot reproducibility. When providing an undercoat layer mainly containing pigments on the support, all general organic or inorganic pigments can be used, but in particular JIS-K5 pigments can be used.
It is preferable to have an oil absorption of 40 cc/100 g or more based on 10 liters, and specific examples include calcium carbonate, barium sulfate, titanium oxide, talc, waxite, kaolin, shokai kaolin, aluminum hydroxide, non-quality silica, and urea. Examples include formalin resin powder and polyethylene resin powder.

When applying these pigments to a support, the amount of pigment is 2
g/m2 or more, preferably 4 g/m'' or more.

Binders used in the undercoat layer include water-soluble polymers and water-insoluble binders, and the binders may be used alone or in combination of two or more.

Examples of water-soluble polymers include methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, starches, gelatin, gum arabic, casein, styrene-maleic anhydride copolymer hydrolyzate, ethylene-maleic anhydride copolymer hydrolyzate, and imbutylene-maleic anhydride. Acid copolymer hydrolyzate, polyvinyl alcohol,
Examples include carboxy-modified polyvinyl alcohol and polyacrylamide.

As the water-insoluble binder, synthetic rubber latex or resin emulsion is generally used, such as styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex, methyl acrylate-butadiene rubber latex, vinyl acetate emulsion, etc. Which can be mentioned.

The amount of binder used is 3~ compared to the pigment! 00% by weight, preferably 5 to 50% by weight. Wax, anti-fading agent, surfactant, etc. may be added to the undercoat layer.

Pigments used as additives in the present invention include kaolin and baked kaolin. Talc, waxite, diatomaceous earth, calcium carbonate, aluminum hydroxide. Magnesium hydroxide.
Zinc oxide, Ritobon. Non-quality silica, colloidal silica. Calcined gypsum, silica, magnesium carbonate, titanium oxide, alumina. Barium carbonate, barium sulfate. mica,
Microhull-7. Urine m-formalin filler polyester particles. Examples of metal soaps include cellulose fillers and higher fatty acid polyvalent metal salts. For example, zinc stearate. Aluminum stearate, calcium stearate. Examples include zinc oleate. Also, in the present invention. It is preferable to use a wax with a melting point of 40 to 120@C from the viewpoint of head matching for facsimile machines. As a wax, the melting point is 40~
At 120°C, paraffin wax, polyethylene wax, carnauba wax, microcrystalline wax, candelia wax, montan wax,
Examples include fatty acid amide wax.

Among these, paraffin wax, microcrystalline wax, montan wax, and fatty acid amide wax are preferred, and paraffin wax, montan wax, and methylol stearamide having a melting point of 50 to 1009 C are particularly preferred.

The amount of wax used is 5 to 200% of the electron-donating colorless dye.
% by weight, preferably 20-150% by weight.

The hindered phenol compound is preferably a phenol derivative in which at least one of the 2nd or 6th positions is substituted with a branched alkyl group. As a Shibagai ray absorber,
Cinnamic acid derivative. For example, penzophenone X conductor, penzotriazolylphenol rust conductor, etc. α-cyanoβ-
Butyl phenylcinnamate, 0-penzotriazolylphenol. 0-penzotriazolyl p-chlorophenol. 0-penzotriazolyl-2,4-di-t-butylphenol. 0-penzotriazolyl-2,4-di-t-
Octylphenol is a water-resistant agent. N
-Methylolurea N-methylolmelamine. Water-soluble initial condensate such as urea-formalin. Glyoxal. Nodialdehyde compounds such as glutaraldehyde. boric acid. [Inorganic crosslinking agents such as sand. Polyacrylic acid. Examples include blend heat treatment of methyl vinyl ether-maleinthane copolymer, inbutylene-maleic anhydride copolymer, etc. Materials used for the protective layer include polyvinyl alcohol,
Carboxy-modified polyvinyl alcohol, vinyl acetate-acrylamide copolymer. Silicon-modified polyvinyl alcohol. starch. Modified starch, methyl cellulose. Carboxymethylcellulose. Hydroxymethylcellulose. Gelatins. Gum arabic, casein. Styrene-maleic acid copolymer hydrolyzate. Styrene-maleic acid copolymer ester hydrolyzate. Inbutylene-maleic anhydride copolymer hydrolyzate, polyacrylamide derivative,
Polyvinylpyrrolidone, polystyrene sodium sulfonate. Water-soluble polymers such as sodium alginate, styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex. Methyl acrylate-butadiene rubber latex. Water-insoluble polymers such as vinyl acetate emulsions are used. Also in the protective layer. For the purpose of improving matching with the thermal head. Pigment. Metal soap, wax. Water resistance agents, etc. may be added. Also. When applying a protective layer onto a heat-sensitive coloring layer. Surfactants may be added to obtain a uniform protective layer. As a surfactant. Alkali metal salt of sulfoconic acid.
Fluorine-containing surfactants are used. in particular. Preferred are sodium salts or ammonium salts of di(n-hexyl)sulfosuccinic acid, di(2-ethylhexyl)sulfosuccinic acid, etc. Anionic surfactants are effective. For use with pressure sensitive paper, U.S. Patent No. 2,505.47
No. 0, No. 2,505.471, No. 2,505.489
No. 2,548,366, No. 2,712.507, No. 2,730.456, No. 2,730.457,
3,103.404, 3,418.250, 4. ．． It may take a variety of forms as described in prior patents such as No. 010.038. Most commonly, it consists of at least one sheet containing separately an electron-donating colorless dye and an electron-accepting compound.

A method of manufacturing capsules is described in U.S. Pat. No. 2.800.
457, a method using coacervation of a hydrophilic colloid sol described in British Patent No. 2,800.458, British Patent No. 867.797, British Patent No. 950.443, British Patent No. 9
Examples include the interfacial polymerization method described in US Pat. No. 89.264 and US Pat. No. 1,091,076, and the method described in US Pat.

In general, electron-donating colorless dyes are used alone or in combination as solvents (alkylated naphthalene, alkylated diphenyl, alkylated diphenylmethane, alkylated terphenyl, alkylated terphenyl, etc.).
It is dissolved in organic oils such as chlorinated paraffin; vegetable oils such as cotton oil and castor oil; animal oils; mineral oils, or mixtures thereof, etc.) and contained in microcapsules to produce paper, high-quality paper, and plastic sheets. A coloring agent sheet is obtained by applying the coloring agent to resin-coated paper or the like.

In addition, an electron-accepting compound and optionally additives, alone or in combination, are dispersed in a binder such as styrene-butadiene latex or polyvinyl alcohol, and are used together with pigments to support paper, plastic sheets, resin-coated paper, etc. A developer sheet is obtained by applying it to the body.

As a binder, carboxy-modified styrene-butadiene latex and water-soluble polymer can be used together. Light resistance.
Preferable from the standpoint of water resistance. In addition, as a pigment, the average particle size is 5.
．． Calcium carbonate of 0μ or less is 6゜0% by weight of the total U material.
It is preferable to use the above from the viewpoint of color developing ability. The amounts of the electron-donating colorless dye and the electron-accepting compound to be used depend on the desired coating thickness, the form of the pressure-sensitive recording paper, the capsule manufacturing method, and other conditions, and may be appropriately selected depending on the conditions. It is easy for one skilled in the art to determine this amount to use.

(Examples of the invention) Examples are shown below, but the invention is not limited thereto. Unless otherwise specified in the examples. weight%
represents. Example 1 l) Preparation of capsule sheet containing electron-donating colorless dye 5 parts of a partial sodium salt of polyvinylbenzenesulfonic acid (VERSA, TL500, manufactured by National Starch Co., Ltd.) was dissolved in 95 parts of water. To this was added an aqueous solution of sodium hydroxide to adjust the pH to 4.0.On the other hand, the electron-donating colorless dye 2-anilino-3-methyl-6-N-ethyl-N
-C3- 100 parts of diisobrobylnaphthalene in which 4.5% of (4-methoxybenzoyloxy)propyl]aminofluorane was dissolved was emulsified in 100 parts of a 5% aqueous solution of the -Is-IJium salt of the polyvinylbenzenesulfonic acid. An emulsion with a particle size of 4.0μ in diameter was obtained by dispersion. Separately 6 parts of melamine. A 37% by weight formaldehyde aqueous solution 11B and water 30B were heated and stirred at 60°C to obtain a transparent aqueous solution of a melamine formaldehyde prepolymer. This aqueous solution was mixed with the above emulsion. While stirring, the pH was adjusted to 6.0 with an aqueous phosphoric acid solution, the temperature of the solution was raised to 65°C, and stirring was continued for 6 hours. This capsule liquid was cooled to room temperature and adjusted to pH 9.0 with an aqueous sodium hydroxide solution. To this dispersion, 200 parts of a 10% by weight aqueous polyvinyl alcohol solution and 50 parts of starch particles were added. A 20% solids concentration solution of the microcapsule dispersion was prepared by adding water. This coating liquid was applied to a 50 g/m' base paper using an air knife coater so that the solid content was 5 g/m', and then dried. A capsule sheet containing an electron-donating colorless dye was obtained. 2) 3.5-bis(α-methylbenzyl)zinc salicylate 1 manufactured by IA as an electron-accepting compound sheet
Part 4. Calcium carbonate 801. A dispersion of zinc oxide 20B, 1 part of sodium hexametaphosphate, and 200 parts of water was dispersed using a sand glider so that the average particle size was 3 μm. To this dispersion were added 100 parts of a 10% PVA aqueous solution and 10 parts of carpoxy-modified SBR latex (as solid content). Add water so that the solid content concentration is 20%,
The coating liquid was obtained. 5. Apply this coating liquid to 5"Og/m' base paper.
It was applied using an air knife coater so that a solid content of 0 g/m'' was applied. It was dried to obtain an electron-accepting compound sheet. The surface of the microcapsule sheet containing an electron-donating colorless dye was
When it was layered on an electron-accepting compound sheet and applied a load of 400 kg/cm' to develop color, the color developed was a deep black hue. Example-2 2-anilino-3-methyl-6-N-ethyl-N-(3-(4-methoxybenzoyloxy)probyl)aminofluorane, which is an electron-donating colorless dye, and bisphenol A, which is an electron-accepting compound. , 20 g each of l-phenoxy-2-(4-methoxyphenoxy)propane, which is a thermofusible compound, was separated with 100 g of 5% polyvinyl alcohol (Kuraray PVA 105) aqueous solution in a Pall mill for one day and night.Volume average. The particle size was set to 3μ.Meanwhile, 80g of calcined kaolin (Anisilex-93) was dispersed with 160g of a 0.5% solution of sodium hexametaphosphate using a homogenizer. Mix 5 g of dye dispersion, log of electron-accepting compound dispersion, 10 g of diaryloxyalkane compound dispersion, and 22 g of calcined kaolin dispersion.Additionally, 4 g of zinc stearate emulsion and 2% (2-ethylhexyl) A coating solution was obtained by adding 5 g of an aqueous solution of sodium sulfosuccinate. This coating solution was applied with a wire bar to a dry coating amount of 6 g/m' on high-quality paper with a basis weight of 50 g/m'. A coated paper was obtained by rendering.The coated paper obtained in the above manner was applied to a thermal head manufactured by Kyocera ■ (
KLT-216-8MPD1) and 10 just before the head
Using a thermal printing experimental device with a pressure roll of 0 kg/cd, printing was performed with a pulse width of 1.0 while using the pressure roll under the conditions of a head voltage of 24 V and a pulse cycle of 10 ms, and the print density was measured using a Macbeth reflection densitometer. Measured with RD-918. Color density is 1. It was 38. Example-3 The 2-anilino-3-methyl-6-N-ethyl-N=(3-(4-methoxybenzoyloxy)probyl)aminofluorane of Example-2 was converted into 2-anilino-3-methyl-6-N-ethyl
A coated paper was obtained in the same manner as in Example 2, except that methyl-6-N-ethyl-N-(3-(4-methylbenzoyloxy)propyl)aminofluorane was used.Example-
When the color was developed in the same manner as in 2, the color density was 1.35. Comparative example

Claims (1)

[Claims] A recording material using an electron-donating colorless dye and an electron-accepting compound, characterized in that the electron-donating colorless dye contains a fluoran derivative having an alkylamino group having an acyloxy group at the 6-position.