JPH04368882A - Recording material - Google Patents

Abstract

PURPOSE:To obtain a recording material improved in color development by using a compound represented by a specific general formula as an electron donating leuco dye. CONSTITUTION:In a recording material utilizing the development of a color due to the contact of an electron donating leuco dye with an electron acceptive compound, as the electron donating leuco dye, a compound represented by formula I (wherein R1 and R2 are a hydrogen atom, an alkyl group or an aryl group, R3 is a hydrogen atom, an alkyl group, an aryl group or an acyl group, R4 is a hydrogen atom, an alkyl group, an alkoxy group, an alkylthio group, an arylthio group, a substituted amino group, a hydroxy group, a halogen atom, an acyloxy group, a cyano group or a nitro group, Ar is an aniline or indole residue which may have a substituent, a ring A is a benzene, naphthalene, pyridine or quinoline ring which may have a substituent and m is an integer of 1-3) is used. By this method, the recording material improved in color forming properties can be obtained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to recording materials, and more particularly to recording materials with improved color development.

0002

[Prior Art] Recording materials using electron-donating colorless dyes and electron-accepting compounds include pressure-sensitive paper, thermal paper, 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, US Patent No. 4
No. 480052, No. 4436920, No. 480014
No. 9, JP 60-23992, JP 60-123
556, 60-123557, etc.

[0003] In recent years, research has been carried out to improve the properties of recording materials, such as (1) color density and color sensitivity, and (2) fastness before use and color image fastness. The present inventors have discovered that specific compounds are effective in improving these properties.

0004

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording material using an electron-donating colorless dye with good coloring properties.

[0005]

[Means for Solving the Problems] The above object has been achieved by a recording material characterized in that a compound represented by the following general formula (1) is used as the electron-donating colorless dye. General formula (1)

[0006]

[Case 2]

In the formula, R1 and R2 are a hydrogen atom, an alkyl group, or an aryl group, and R3 is a hydrogen atom, an alkyl group,
Aryl group, acyl group, R4 is hydrogen atom, alkyl group, alkoxy group, aryl group, aryloxy group, alkylthio group, arylthio group, substituted amino group, hydroxy group, halogen atom, acyloxy group, cyano group, nitro group , Ar is an aniline residue or indole residue which may have a substituent, ring A is a benzene ring, naphthalene ring, pyridine ring, pyrazine ring, or quinoline ring which may have a substituent, m represents an integer from 1 to 3.

Note that the alkyl group and aryl group further include an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a halogen atom, a nitro group, a cyano group, a substituted carbamoyl group, a substituted sulfamoyl group, a substituted amino group, and a substituted oxycarbonyl group. , a substituted oxysulfonyl group, an alkylthio group, an arylsulfonyl group, and the like.

Specifically, R1 and R2 are hydrogen atoms, alkyl groups having 1 to 18 carbon atoms, and 6 to 12 carbon atoms.
An aryl group of is preferred. R1 and R2 are hydrogen atom, methyl group, ethyl group, propyl group, butyl group,
pentyl group, hexyl group, octyl group, 2-ethylhexyl group, dodecyl group, octadecyl group, cyanoethyl group, benzyl group, methylbenzyl group, chlorobenzyl group,
Examples include phenethyl group, β-methoxyethyl group, β-ethoxyethyl group, β-phenoxyethyl group, β-(4-methoxyphenoxy)ethyl group, phenyl group, and methylphenyl group.

R3 is a hydrogen atom, having 1 to 18 carbon atoms
An alkyl group having 6 to 12 carbon atoms, an acyl group having 2 to 18 carbon atoms, and an alkyl group having 1 to 12 carbon atoms are particularly preferred.

R3 is a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a 2-ethylhexyl group, a dodecyl group,
Octadecyl group, cyanoethyl group, benzyl group, methylbenzyl group, chlorobenzyl group, phenethyl group, β-methoxyethyl group, β-ethoxyethyl group, β-phenoxyethyl group, β-(4-methoxyphenoxy)ethyl group, phenyl group, methylphenyl group, acetyl group, propionyl group, butyryl group, valeryl group, pivaloyl group, and benzoyl group.

R4 is a hydrogen atom, having 1 to 18 carbon atoms
Preferred are alkyl groups, alkoxy groups, alkylthio groups, substituted amino groups, acyloxy groups, aryl groups having 6 to 12 carbon atoms, aryloxy groups, arylthio groups, hydroxy groups, halogen atoms, cyano groups, and nitro groups.

R4 is a hydrogen atom, methyl group, ethyl group, propyl group, butyl group, octyl group, phenyl group, tolyl group, benzyl group, phenethyl group, methoxy group, ethoxy group, propoxy group, butoxy group, octyl group. Examples include oxy group, benzyloxy group, phenoxyethoxy group, phenoxy group, methylthio group, chlorine atom, bromine atom, fluorine atom, nitro group, cyano group, dimethylamino group, diethylamino group, acetylamino group, and acetyloxy group.

[0014] Ar is preferably a group represented by the following general formulas (2) or (3). General formula (2)

[0015]

[Chemical 3]

General formula (2)

[0017]

[C4]

In the above formula, R5, R6, R8, R9
represents a group similar to R1 described above, R7 and R10 represent a group similar to R4 described above, and n represents an integer from 1 to 4. Further, R5 and R6 are bonded to each other to form a ring which may contain a 5- to 8-membered heteroatom including the nitrogen atom to which they are bonded, such as pyrrolidine, piperidine, morpholine, thiomorpholine, piperazine, caprolactam. It may form a ring. Also, R5 and R6 are NR5
It may be bonded to the carbon atom at the ortho position of R6 to form a tetrahydroquinoline, indoline, or julolidine ring.

NR5 R6 is dimethylamino group, diethylamino group, dipropylamino group, dibutylamino group, dipentylamino group, dihexylamino group, dioctylamino group, diphenylamino group, ditolylamino group, dibenzylamino group, N-methyl -N-ethylamino group, N-methyl-N-butylamino group, N-ethyl-N-butylamino group, N-ethyl-N-β-methoxyethylamino group, N-ethyl-N-β-ethoxyethyl Amino group, N-ethyl-N-β-phenoxyethylamino group, N-methyl-N-β-cyanoethylamino group, N
-Methyl-N-β-chloroethylamino group, N-ethyl-N-cyclohexylamino group, N-ethyl-N-pentylamino group, N-ethyl-N-tetrahydrofurfurylamino group, N-ethyl-N- tolylamino group, N-ethyl-N-methoxyphenylamino group, N-ethyl-N
-benzylamino group, N-ethyl-N-chlorobenzylamino group, pyrrolidino group, piperidino group, morpholino group, and piperazino group.

As the substituent for ring A, an alkyl group, a halogen atom, an alkoxy group, a dialkylamino group, and an alkylamino group are preferable.

Next, specific examples of the color former of the present invention will be shown, but the present invention is not limited thereto.

[0022]

[C5]

[0023]

[C6]

[0024]

[C7]

[0025]

[Chemical formula 8]

[0026]

[Chemical formula 9]

These colorless dyes include well-known triphenylmethane phthalide compounds, fluoran compounds, phenothiazine compounds, indolyl phthalide compounds, leucoauramine compounds, rhodamine lactam compounds, It is also possible to assemble recording materials by using it in combination with various compounds such as triphenylmethane compounds, triazene compounds, spiropyran compounds, and fluorene compounds. In this case, it is preferable to use the above-mentioned colorless dye in an amount of 30% or more from the viewpoint of improving properties.

Regarding these, specific examples of phthalides are given in US Pat. No. 23,024 and US Pat. No. 3,4.
No. 91,111, No. 3,491,112, No. 3,49
No. 1,116 and No. 3,509,174; specific examples of fluorans are US Pat. Nos. 3,624,107 and 3,509,174;
No. 627,787, No. 3,641,011, No. 3, 4
No. 62,828, No. 3,681,390, No. 3,92
Nos. 0,510 and 3,959,571; specific examples of spirodipyrans are described in U.S. Pat. No. 3,971,808; pyridine and pyrazine compounds are described in U.S. Pat. No. 3,775;
No. 424, No. 3,853,869, No. 4,246,3
No. 18, specific examples of fluorene compounds are European Patent No. 278
, No. 614, etc.

Examples of electron-accepting compounds that impart color upon contact with colorless dyes include conventional compounds such as phenol derivatives, salicylic acid derivatives, benzoic acid derivatives, metal salts of aromatic carboxylic acids, acid clay, bentonite, novolak resins, and metals. Treated novolac resins, metal complexes, etc. are used, and these may be used in combination. Examples of these are JP-A-40-9309, JP-A-45-14039, JP-A-52-140483, JP-A-48-51510,
JP-A-57-210886, JP-A-58-87089
No., JP-A-59-11286, JP-A-60-1767
No. 95, JP-A No. 61-95988, U.S. Patent No. 3,76
No. 7,449, No. 4,219,219, No. 4,269
, No. 893, No. 4,374,671, No. 4,687,
It is described in No. 869, etc. Especially salicylic acid derivatives,
Combinations with phenol derivatives and metal complexes are preferred. When these are applied to recording materials, they are used in the form of fine dispersions or fine droplets, or in the form of films.

Furthermore, in this case, various additives well known in the fields of recording materials and polymer resins, such as pigments, waxes, antistatic agents, ultraviolet absorbers, antifoaming agents, etc.
Additives such as conductive agents, fluorescent dyes, and surfactants are used.

When used with pressure sensitive paper, US Pat.
No. 05,470, No. 2,505,471, No. 2,50
No. 5,489, No. 2,548,366, No. 2,712
, No. 507, No. 2,730,456, No. 2,730,
No. 457, No. 3,103,404, No. 3,418,2
It can take various forms as described in prior patents such as No. 50 and No. 4,010,038. Most commonly it consists of at least one pair of sheets containing separately an electron-donating colorless dye and an electron-accepting compound.

[0032] Methods for manufacturing capsules include a method using coacervation of a hydrophilic colloid sol described in US Pat. 950,44
No. 3, No. 989,264, No. 1,091,076, etc., or the interfacial polymerization method described in US Pat. No. 3,103.
, No. 404, etc. The capsule wall material is preferably a synthetic resin-based wall material, for example, a polyurethane and/or polyurea-based material, or a melamine resin-based material.

In general, electron-donating colorless dyes are used alone or in combination in a solvent (synthetic oil such as alkylated naphthalene, alkylated diphenyl, alkylated diphenylmethane, alkylated terphenyl, chlorinated paraffin, etc.; cotton oil;
A color former sheet is created by dissolving vegetable oil such as castor oil, animal oil, mineral oil, or a mixture thereof, incorporating it into microcapsules, and applying it to paper, high-quality paper, plastic sheet, resin-coated paper, etc. get.

In addition to the electron-donating colorless dye, ultraviolet absorbers, antioxidants, and the like may be added as additives to the microcapsules. In particular, benzotriazole-based ultraviolet absorbers,
It is preferable to add a hindered amine antioxidant, a hindered phenol antioxidant, an aniline antioxidant, a quinoline antioxidant, or the like.

In addition, the electron-accepting compound and optionally additives may be dispersed alone or in a mixture in a binder such as styrene-butadiene latex or polyvinyl alcohol, and used together with the pigment described below to produce paper, plastic sheets, and resin-coated paper. A developer sheet is obtained by coating a support such as the following. 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.

When used for thermal paper, British Patent 2,2
It takes the form as described in No. 00,220, etc. Specifically, the electron-donating colorless dye and the electron-accepting compound are used after being pulverized and dispersed in a dispersion medium to a particle size of 10 μm or less, preferably 3 μm or less. As a dispersion medium, generally 0.
An aqueous polymer solution having a concentration of about 5 to 10% is used, and dispersion is carried out using a ball mill, sand mill, horizontal sand mill, attritor, colloidal mill, or the like.

The ratio of the electron-donating colorless dye to the electron-accepting compound used is preferably between 1:10 and 1:1 by weight, and particularly preferably between 1:5 and 2:3. At that time, it is preferable to use a thermofusible substance in combination. These are used in finely dispersed form at the same time as the electron-donating colorless dye or simultaneously with the electron-accepting compound. These are added at a weight ratio of 20% or more and 300% or less, particularly preferably 40% or more and 150% or less, based on the electron-accepting compound.

[0038] Additives may be added to the coating liquid thus obtained, as necessary, in order to meet various requirements. Examples of additives include dispersing oil-absorbing substances such as inorganic pigments and polyurea fillers in the binder in order to prevent the recording head from becoming dirty during recording.
Fatty acids, metal soaps, etc. are added to improve the mold releasability from the head. Therefore, in general, in addition to electron-donating colorless dyes and electron-accepting compounds that directly contribute to color development,
Additives such as thermofusible substances, pigments, waxes, antistatic agents, ultraviolet absorbers, antifoaming agents, conductive agents, fluorescent dyes, and surfactants are coated onto a support to form a recording material. become. Furthermore, a protective layer may be provided on the surface of the heat-sensitive recording layer, if necessary. Two or more protective layers may be laminated as necessary. Further, a coating liquid similar to that of a protective layer may be applied to the back surface in order to correct the curl balance of the support or to improve chemical resistance from the back surface. An adhesive may be applied to the back side and a release paper may be further added to form a label.

[0039] Usually, the electron-donating colorless dye and the electron-accepting compound are dispersed in a binder and applied. Water-soluble binders are generally used, such as polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, epichlorohydrin-modified polyamide, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride salicylic acid. Examples include copolymers, polyacrylic acid, polyacrylic acid amide, methylol-modified polyacrylamide, starch derivatives, casein, and gelatin. Further, for the purpose of imparting water resistance to these binders, a water resistance agent may be added, or an emulsion of a hydrophobic polymer, specifically, a styrene-butadiene rubber latex, an acrylic resin emulsion, etc. may be added. The coating liquid is applied onto base paper, wood-free paper, synthetic paper, plastic sheet, resin-coated paper, or neutral paper.

Examples of thermofusible substances include JP-A-58-5
No. 7989, Japanese Unexamined Patent Publication No. 58-87094, etc. Examples of such compounds include 2-benzyloxynaphthalene, 4-benzylbigenyl, 1,2-di-m-tolyloxyethane, 1,2-diphenoxyethane, 1,
4-diphenoxybutane, 1-phenoxy-2-p-ethylphenoxyethane, 1-p-methoxyphenoxy-
2-phenoxypropane, 1-phenoxy-2-p-methoxyphenoxypropane, 1,2-bis-p-methoxyphenoxypropane, 1,3-bis-p-methoxyphenoxypropane, 1-p-methoxyphenoxy-2-
o-chlorophenoxyethane, 1-phenoxy-2-p
-methoxyphenylthioethane, 1,2-bis-p-methoxyphenylthioethane, 1-p-methylphenoxy-2-p-methoxyphenylthioethane, bis-[β-
(p-methoxyphenoxy)ethyl]ether, 4-(
4-chlorobenzyloxy)ethoxybenzene, 4-(
Examples include ether compounds such as p-methoxybenzylthio)anisole, stearic acid amide, methylene bisstearamide, stearic acid anilide, behenic acid amide, stearic acid aniside, and stearyl urea.

Pigments include kaolin, calcined kaolin, talc, diatomaceous earth, calcium carbonate, aluminum hydroxide, magnesium hydroxide, zinc oxide, lithopone, amorphous silica, colloidal silica, calcined gypsum, silica, magnesium carbonate, oxidized titanium, alumina, barium carbonate,
Barium sulfate, mica, microballoons, urea-formalin fillers, polyester particles, cellulose fillers, etc. are used.

[0042] As the metal soap, higher fatty acid polyvalent metal salt,
For example, zinc stearate, aluminum stearate,
Examples include calcium stearate and zinc oleate. Examples of waxes include paraffin wax, carboxy-modified paraffin wax, carnauba wax, microcrystalline wax, polyethylene wax, polystyrene wax, higher fatty acid esters, amides, and the like.

As the hindered phenol compound, a phenol derivative in which at least one of the 2nd and 6th positions is substituted with a branched alkyl group is preferred. For example 1,
1,3-tris(2-methyl-4-hydroxy-5-t
-butylphenyl)butane, 1,1,3-tris(2-
Ethyl-4-hydroxy-5-t-butylphenyl)butane, 1,1,3-tris(3,5-di-t-butyl-
4-hydroxyphenyl)butane, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)propane, 4,4-butylidenebis(6-t-butyl-3-methylphenol, 4 , 4-thiobis(3-methyl-6-t-butylphenol), 2,2-methylenebis(6-t-butyl-4-methylphenol), 2,
2-methylenebis(6-t-butyl-4-ethylphenol), octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 1,3,
5-trimethyl-2,4,6-tris(3,5-di-t
-butyl-4-hydroxybenzyl)benzene, 2,2
, 6,6-tetramethyl-4-piperidinyl sebacate, tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propinate]methane, and the like. The amount of these hindered phenol compounds to be used is preferably 1 to 200% by weight based on the electron accepting compound, and more preferably 5 to 1% by weight.
00% by weight.

Examples of the ultraviolet absorber include cinnamic acid derivatives, benzophenone derivatives, and benzotriazolylphenol derivatives, such as butyl α-cyano-β-phenylcinnamate, o-benzotriazolylphenol, and o-benzotriazolylphenol. Zolyl-p-chlorophenol, o-benzotriazolyl-p-methylphenol, o-benzotriazolyl-2,4-di-t-butylphenol, o-benzotriazolyl-2,4-di- Examples include t-octylphenol.

[0045] As the water resistance agent, N-methylol urea,
Water-soluble initial condensates such as N-methylolmelamine and urea-formalin, dialdehyde compounds such as glyoxal and glutaraldehyde, inorganic crosslinking agents such as boric acid and borax,
Examples include blend heat treatment of polyacrylic acid, methyl vinyl ether-maleic acid copolymer, isobutylene-maleic anhydride copolymer, and the like.

Materials used for the protective layer include polyvinyl alcohol, carboxy-modified polyvinyl alcohol, vinyl acetate-acrylamide copolymer, silicon-modified polyvinyl alcohol, starch, modified starch, methylcellulose, carboxymethylcellulose, hydroxymethylcellulose, gelatin, and gum arabic. , casein, styrene-
Maleic acid copolymer hydrolyzate, styrene-maleic acid copolymer half ester hydrolyzate, isobutylene-maleic anhydride copolymer hydrolyzate, polyacrylamide derivatives, polyvinylpyrrolidone, polystyrene sodium sulfonate, sodium alginate, etc. Water-soluble polymers and water-insoluble polymers such as styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex, methyl acrylate-butadiene rubber latex, and vinyl acetate emulsion are used.

[0047] In addition, pigments, metal soap, wax,
A waterproofing agent or the like may be added. When coating the protective layer on the thermosensitive coloring layer, a surfactant may be added in order to obtain a uniform protective layer. As the surfactant, a sulfosuccinic acid-based alkali metal salt, a fluorine-containing surfactant, etc. are used. Specifically, sodium salts or ammonium salts such as di-(n-hexyl)sulfosuccinic acid and di-(2-ethylhexyl)sulfosuccinic acid are preferred, but anionic surfactants are effective.

[0048] Photosensitive and pressure sensitive paper is disclosed in, for example, US Pat. No. 4,800,
It is manufactured by the method described in No. 149 and the like. Generally, crosslinking of photopolymerization initiators such as silver bromide, silver bromide, silver behenate, Michler's ketone, benzoin derivatives, benzophenone derivatives, etc. and polyfunctional monomers such as polyallyl compounds, poly(meth)acrylates, poly(meth)acrylamides, etc. The agent is encapsulated in a capsule of a synthetic resin such as polyether urethane or polyurea together with an electron-donating colorless dye and, if necessary, a solvent. After imagewise exposure, the unexposed area is colored by contacting with an electron-accepting compound using an electron-donating colorless dye.

[0049]

[Examples] Examples are shown below, but the present invention is not limited thereto. % represents weight % unless otherwise specified.

(Example 1) (1) Preparation of capsule sheet containing electron-donating colorless dye 5 parts of a partial sodium salt of polyvinylbenzenesulfonic acid (manufactured by National Starch Co., Ltd., VERSA, TL500) was dissolved in 95 parts of hot water. After that, cool it down. A sodium hydroxide aqueous solution was added to this to adjust the pH to 4.0. On the other hand, 100 parts of diisopropylnaphthalene in which 3.5% of the compound of Example (1) was dissolved was emulsified and dispersed in 100 parts of a 5% aqueous solution of a partial sodium salt of the polyvinylbenzenesulfonic acid to form particles with a diameter of 4.0μ. An emulsion was obtained. Separately, 6 parts of melamine, 11 parts of a 37% by weight formaldehyde aqueous solution, and 30 parts of water were heated and stirred at 60° C., and after 30 minutes, a transparent aqueous solution of a melamine-formaldehyde prepolymer was obtained.

[0051] This aqueous solution was mixed with the above emulsion. While stirring, the pH was adjusted to 6.0 with a 2M 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 polyvinyl alcohol aqueous solution and 50 parts of starch particles were added, and water was added to give a microcapsule dispersion with a solid content concentration of 2.
A 0% solution was prepared. This coating solution was applied to a base paper of 50 g/m2 using an air knife coater so that the solid content was 5 g/m2, and dried to obtain a capsule sheet containing an electron-donating colorless dye.

(2) Preparation of electron-accepting compound sheet 3,
10 parts of 5-bis-α-methylbenzylsalicylic acid zinc salt to 20 parts of 1-isopropylphenyl-2-phenylethane
part and dissolved. This was mixed with 50 parts of a 2% polyvinyl alcohol aqueous solution and 0.1 part of a 10% dodecylbenzenesulfonic acid triethanolamine salt aqueous solution and emulsified so that the average particle size was 3 μm. Next, calcium carbonate 8
0 parts, 20 parts of zinc oxide, 1 part of sodium hexametaphosphate
After mixing a dispersion consisting of 200 parts of water and 200 parts of water with the above emulsion, 1 part of a 10% PVA aqueous solution was added as a binder.
00 parts and 10 parts (as solid content) of carboxy-modified SBR latex were added and water was added so that the solid content concentration was 20% to obtain a coating liquid (A).

Next, 10 parts of the electron-accepting compound, 20 parts of Silton clay, 60 parts of calcium carbonate, and 20 parts of zinc oxide were added.
A dispersion of 1 part of sodium hexametaphosphate and 200 parts of water was ground to an average particle diameter of 3 parts using a sand grinder.
Distributed so that μ. To this dispersion were added 16 parts of a 10% PVA aqueous solution, 100 parts of a 10% PVA aqueous solution, and 10 parts of carboxy-modified SBR latex (as solid content), and water was added so that the solid content concentration was 20%.
) was obtained. Coating liquid (A) and coating liquid (B) were mixed at a ratio of 1:1 in terms of electron-accepting compound, and 50 g/m2 of base paper was coated.
．． It was coated using an air knife coater so that a solid content of 0 g/m2 was coated and dried to obtain an electron-accepting compound sheet.

The surface of the microcapsule sheet containing an electron-donating colorless dye was superimposed on the electron-accepting compound sheet.
Lowercase letter m on a 47-inch electronic typewriter
24 hours after color development, the density was measured using a Macbeth reflection densitometer (Macbeth Co., Ltd. RD9).
18). Color density is 0.30 (λmax: 6
17 nm). In addition, the obtained color image shows that chemicals,
It showed good resistance to sunlight etc.

(Comparative Example 1) A microcapsule sheet containing an electron-donating colorless dye was obtained in the same manner as in Example 1, except that the compound represented by Chemical Formula 10 was used instead of the electron-donating colorless dye of Example 1. . When this sheet was colored in the same manner as in Example 1, the color density was 0.25.

[0056]

[Chemical formula 10]

(Example 2) A microcapsule sheet containing an electron-donating colorless dye was prepared in the same manner as in Example 1 except that the compound shown in specific example (5) was used instead of the electron-donating colorless dye of Example 1. I got it. When this sheet was colored in the same manner as in Example 1, the color density was 0.35 (λmax: 60
0 nm). Moreover, the obtained colored image showed good resistance to chemicals, sunlight, etc.

(Comparative Example 2) A microcapsule sheet containing an electron-donating colorless dye was obtained in the same manner as in Example 1, except that the compound represented by Chemical Formula 11 was used instead of the electron-donating colorless dye of Example 1. . When this sheet was colored in the same manner as in Example 1, the color density was 0.29.

[0059]

[Chemical formula 11]

(Example 3) A microcapsule sheet containing an electron-donating colorless dye was prepared in the same manner as in Example 1 except that the compound shown in Specific Example (7) was used instead of the electron-donating colorless dye of Example 1. I got it. When this sheet was colored in the same manner as in Example 1, the color density was 0.37 (λmax: 60
2 nm). Moreover, the obtained colored image showed good resistance to chemicals, sunlight, etc.

(Comparative Example 3) A microcapsule sheet containing an electron-donating colorless dye was obtained in the same manner as in Example 1, except that the compound represented by Chemical Formula 12 was used instead of the electron-donating colorless dye of Example 1. . When this sheet was colored in the same manner as in Example 1, the color density was 0.32.

[0062]

[Chemical formula 12]

(Example 4) A microcapsule sheet containing an electron-donating colorless dye was prepared in the same manner as in Example 1 except that the compound shown in Specific Example (14) was used instead of the electron-donating colorless dye of Example 1. I got it. When this sheet was colored in the same manner as in Example 1, the color density was 0.31 (λmax: 5
55 nm). In addition, the obtained color image shows that chemicals,
It showed good resistance to sunlight etc.

(Comparative Example 4) A microcapsule sheet containing an electron-donating colorless dye was obtained in the same manner as in Example 1, except that the compound represented by Chemical Formula 13 was used instead of the electron-donating colorless dye of Example 1. . When this sheet was colored in the same manner as in Example 1, the color density was 0.26.

[0065]

[Chemical formula 13]

[0066]

[Effects of the Invention] By using the compound represented by the general formula (1), the present invention makes it possible to provide a recording material with good color development.

Claims (1)

[Claims] Claim 1: In a recording material that utilizes color development due to contact between an electron-donating colorless dye and an electron-accepting compound, a compound represented by the following general formula (1) is used as the electron-donating colorless dye. Featured recording material General formula (1) [Chemical formula 1
] In the formula, R1 and R2 are a hydrogen atom, an alkyl group, or an aryl group, and R3 is a hydrogen atom, an alkyl group, or an aryl group.
an acyl group, R4 is a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an alkylthio group,
Arylthio group, substituted amino group, hydroxy group, halogen atom, acyloxy group, cyano group, nitro group, Ar
is an aniline residue or indole residue which may have a substituent, ring A is a benzene ring which may have a substituent,
m represents an integer from 1 to 3; naphthalene ring, pyridine ring, pyrazine ring, quinoline ring;