JPH0371883A - Recording material - Google Patents

Abstract

PURPOSE:To obtain a recording material having a color forming part having absorption in a near infrared region and improved in color forming properties, raw preservability and the stability of a developed color image by using a p-(p-substituted aminophenyl) aminophenylindolylphthalide compound as an electron donating leuco dye. CONSTITUTION:In a recording material utilizing color development due to the contact of an electron donating leuco dye and an electron acceptive compound, a p-(p-substituted aminophenyl) aminophenylindolylphthalide compound is used as the electron donating leuco dye. The use amounts of both of the electron donating leuco dye and the electron acceptive compound may be appropriately selected corresponding to a desired coating thickness, the form of pressure- sensitive recording paper, a capsule preparing method and other conditions. When the electron donating leuco dye and the electron acceptive compound are used in thermal paper, they are ground and dispersed up to a particle size of 10mum or less, pref., 3mum or less in a dispersing medium before use. As the dispersing medium, a water-soluble polymer aqueous solution having concn. of about 0.5-10% is generally used and the wt. ratio of the electron donating leuco dye and the electron acceptive compound is pref. 1:10-1:1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a recording material, and particularly to a recording material in which a color-developing portion has absorption in the near-infrared region.

(Prior Art) Recording materials using electron-donating colorless dyes and electron-accepting compounds are already well known as pressure-sensitive paper, thermal paper, light-sensitive pressure-sensitive paper, electrically conductive thermal recording paper, thermal transfer paper, and the like. For example, see British Patent No. 2,140,449, US Pat. No. 4,480,052, US Pat.

In recent years, optical character reading devices and barcode reading devices have become rapidly popular, and along with this, 700nm
There has been a strong demand for recording materials that have absorption in the near-infrared region of m or more.

Several proposals have been made as electron-donating colorless dyes that absorb in the near-infrared region.
1997.57, 61-284485, 59-
'148695, '51-121035, '51
No.-121037, No. 60-230890, etc. are disclosed. However, no material has yet been obtained that has absorption in the near-infrared region and satisfies color development, shelf life, and stability of colored images.

The present inventors have discovered that specific compounds are effective in improving these properties.

(Objective of the Invention) Therefore, the object of the present invention is to have a color-forming part that has absorption in the near-infrared region, and has good color-forming properties, shelf life, and stability of colored images, and also meets other necessary conditions. The objective is to provide satisfactory recording materials.

(Structure of the Invention) An object of the present invention is to provide a recording material that utilizes color development through contact between an electron-donating colorless dye and an electron-accepting compound, in which p-(p-substituted aminophenyl) is used as the electron-donating colorless dye. ) It was distantly related to recording materials characterized by the use of aminophenylindolphthalide compounds. As the above-mentioned p-substituted aminophenyl group, those shown in -contact (I) are preferable.

represents an integer from 1 to 4.

In addition, an alkyl group represents a saturated, unsaturated or cycloalkyl group, and these have a substituent such as an aryl group, an alkoxy group, an aryloxy group, an acyloxy group, a halogen atom, an acylamino group, an aminocarbonyl group, or a cyano group. You can leave it there.

In addition, the aryl group represents a phenyl group, a naphthyl group, or a heterocyclic group, and these include an alkyl group, an alkoxy group,
．． Substituents such as aryloxy group, halogen atom, nitro group, cyano group, substituted carbamoyl group, substituted sulfamoyl group, substituted amino group, substituted oxycarbonyl group, substituted oxysulfonyl group, alkylthio group, arylsulfonyl group, or phenyl group may have.

Preferred compounds of the present invention are shown in general formula (n).

In the above formula, R1 is a hydrogen atom, an alkyl group, R3-R4 is a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a cyano group, a nitro group, a substituted amino group, a halogen atom, p, q, r In the above formula, Rs' = R- represents a hydrogen atom, an alkyl group, or an aryl group; aSb is an integer from 1 to 4, ring A is an aromatic ring, and R7-R4 and p-r have the above-mentioned meanings.

The R3 to R9 substituents preferably have 18 or less carbon atoms, particularly 12 or less carbon atoms.

More details regarding R4 include hydrogen atom, methyl group, ethyl group, propyl group, butyl group, amyl group, hexyl group, octyl group, octadecyl group, methoxypropyl group, ethoxypropyl group, phenoxyethyl group, cyclopentyl group, cyclohexyl group. , allyl group, benzyl group, phenethyl group, etc.

Among the substituents represented by R1-R4, R*, R*, a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, Aryloxy group having 6 to 12 carbon atoms, chlorine atom, bromine atom, fluorine atom, nitro group, cyano group, amino group, mono- or dialkylamino group having 1 to 12 carbon atoms, mono having 6 to 12 carbon atoms Alternatively, a diarylamino group or an acylamino group having 1 to 12 carbon atoms is preferable.

The substitution position of R8 is preferably the meta position with respect to the amino group from the viewpoint of synthetic handling.

More details regarding R8-R4, R,, R, include hydrogen atom, methyl group, ethyl group, propyl group, butyl group, amyl group, hexyl group, octyl group, octadecyl group, methoxypropyl group, ethoxypropyl group, phenoxy Ethyl group, cyclopentyl group, cyclohexyl group, allyl group,
Phenyl group, tolyl group, benzyl group, phenethyl group, methoxy group, ethoxy group, propoxy group, butoxy group, octyloxy group, phenoxyethoxy group, phenoxy group, chlorine atom, bromine atom, fluorine atom, nitro group, cyano group, Amino group, dimethylamino group, diethylamino group, dipropylamino group, dibutylamine group, dioctylamino group, N-ethyl-N-1so-amylamino group, N-
Examples include methyl-N-benzylamino group, methylamine group, ethylamino group, butylamino group, acetylamino group, phenylamino group, and diphenylamino group.

Among the substituents represented by R8 to R, hydrogen atoms, alkyl groups having 1 to 12 carbon atoms, and aryl groups having 6 to 12 carbon atoms are preferred.

More specifically regarding R3-R7, hydrogen atom, methyl group, ethyl group, propyl group, butyl group, amyl group, hexyl group, octyl group, octadecyl group, methoxypropyl group, ethoxypropyl group, phenoxyethyl group, cyclopentyl group. group, cyclohexyl group, allyl group, phenyl group, tolyl group, benzyl group, phenethyl group, etc.

In the above-mentioned survival A is preferred. R1° is selected from the groups represented by R.

C is an integer from 1 to 6, R11 is an oxygen atom, a sulfur atom,
N R, (R represents a hydrogen atom, an alkyl group, an aryl group, or an acyl group).

Furthermore, in ring A is preferable from the viewpoint of cost and coloring wavelength.

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

In addition, these colorless dyes are already well-known triphenylmethane phthalide compounds, fluoran compounds,
Recording materials can be produced in combination with various compounds such as phenothiazine compounds, indolylphthalide compounds, leucoauramine compounds, rhodamine lactam compounds, triphenylmethane compounds, triazene compounds, spiropyran compounds, and fluorene compounds. It can also be assembled.

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, for example, specific examples of phthalides are U.S. Reissue Patent No. 23,024 and U.S. Patent No. 3°491.111.
No. 3,491,112, No. 3,491.116 and No. 3,509,174, and specific examples of fluorans are U.S. Pat.
No. 7, No. 3゜641.011, No. 3,462,828
No. 3,681,390, No. 3,920,510, No. 3,959,571, and specific examples of spiropyrans are given in U.S. Patent No. 3,971. ．． No. 808, pyridine and pyrazine compounds are disclosed in U.S. Patent No. 3,775.424, U.S. Patent No. 3,853,869, and U.S. Pat. etc. are described.

Examples of electron-accepting compounds that impart color upon contact with colorless dyes include common compounds such as phenol derivatives, salicylic acid derivatives, metal salts of aromatic carboxylic acids, acid clay, bentonite, novolac resins, metal-treated novolac resins, and metal complexes. are used, and these may be used in combination. Examples of these are Tokuko No. 9309, No. 40-9309, and Tokuko No. 4
5-14039, JP 52-140483, JP 48-51510, JP 57-210886,
JP-A-58-87089, JP-A-59-11286, JP-A-60-176795, JP-A-61-9598
No. 8, U.S. Patent No. 3,767°449, U.S. Patent No. 4,219,
No. 219, No. 4,269.893, No. 4,374,6
No. 71, No. 4゜687.869, etc.

Particularly preferred are combinations with phosphoric acid derivatives, phenol derivatives, metal salts of aromatic carboxylic acids, and metal complexes.

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, conductive agents, and fluorescent agents, are used. Additives such as dyes and surfactants are used.

For use with pressure sensitive paper, U.S. Patent 2,505°470
No. 2,505.471, No. 2,505.489, No. 2,548,366, No. 2゜712.507,
2,730,456, 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. It most commonly consists of at least one pair of sheets 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. 867.797, British Patent No. 950,443, British Patent No. 98
No. 9,264, Ibid.

Examples include the interfacial polymerization method described in US Pat. No. 091.076 and the method described in US Pat. No. 3,103,404.

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 as solvents (alkylated naphthalene, alkylated diphenyl, alkylated diphenylmethane, alkylated terphenyl, alkylated terphenyl, etc.).
Synthetic oils such as chlorinated paraffin; vegetable oils such as cotton oil and castor oil; animal oils; mineral oils or mixtures thereof, etc.) are dissolved in microcapsules to produce paper, high-quality paper, plastic sheets, resin coatings, etc. A coloring agent sheet is obtained by applying it to ted paper, etc.

In addition to the electron-donating colorless dye, ultraviolet absorbers, antioxidants, and the like may be added as additives to the microcapsules. In particular, from the viewpoint of improving the stability of the electron-donating colorless dye in the capsule before use and the coloring of the capsule, benzotriazole-based ultraviolet absorbers, hindered amine-based antioxidants, hindered phenol-based antioxidants, aniline-based oxidants, etc. It is preferable to add an inhibitor, a quinoline antioxidant, etc.

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

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, JP-A-62-144゜989
It takes the form as described in Japanese Patent Application No. 62'-244,883 and the like. 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 the dispersion medium, an aqueous polymer solution having a concentration of about 0.5 to 10% is generally 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. 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.

Additives may be added to the coating liquid thus obtained as necessary 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, and also to improve releasability from the head. For this reason, fatty acids, metal soaps, etc. are added. Therefore, in general, in addition to electron-donating colorless dyes and electron-accepting compounds that directly contribute to color development, thermofusible substances, pigments, waxes, antistatic agents, ultraviolet absorbers, antifoaming agents, conductive agents, and fluorescent dyes are used. , surfactants, and other additives are applied onto the support to constitute the recording material.

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.

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, and ethylene-
Examples include maleic anhydride copolymer, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer, 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, styrene-butadiene rubber latex, 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 are disclosed in JP-A-58-57989 and JP-A-58-87094. Examples of such compounds include 2-benzyloxynaphthalene, 4-
Benzyl biphenyl, di-m-)lyloxyethane, l
, 2-diphenoxyethane, l,4-diphenoxybutane, bis-[β-(p-methoxyphenoxy)ethyl]
Ether, l-phenoxy-2-p-ethylphenoxyethane, 1-p-methoxyphenoxy-2-phenoxypropane, 1-phenoxy-2-p-methoxyphenoxypropane, l,2-bis(p-methoxyphenoxy)propane , l, 3-bis(p-methoxyphenoxy)
Propane, 1-p-methoxyphenoxy-2-o-chlorophenoxyethane, 1-p-ethoxyphenoxy-2
-p-chlorophenoxyethane, 4-(p-methoxybenzylthio)anisole, ■-phenoxy 2-p-methoxyphenylthioethane, 1,2-bis(p-methoxyphenylthio)ethane, t-p-methyl Examples include ether compounds such as phenoxy-2-p-methoxyphenylthioethane, stearamide, methylene bisstearamide, stearanilide, behenic acid amide, stearic acid anide, 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, titanium oxide, alumina. , barium carbonate, barium sulfate, mica, microballoons, urea-formalin fillers, polyester particles, cellulose fillers, etc. are used.

Examples of metal soaps include polyvalent metal salts of higher fatty acids, such as zinc stearate, aluminum stearate, 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-)lis(2-methyl-4-hydroxy-5-t-butylphenyl)butane, Ill, 3-)-lis(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-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, tetrakis[methylene-3-(3,5-di-butyl-4-hydroxyphenyl)propinate comethane, 2,2,6.6-tetramethyl-4-piperidinyl sebacate etc. can be mentioned.

The amount of the hindered phenol compound to be used is preferably 1 to 200% by weight, more preferably 5 to 100% by weight, based on the electron accepting compound.

As ultraviolet absorbers, cinnamic acid derivatives, benzophenone derivatives, benzotriazolylphenol derivatives, etc.
For example, butyl α-cyano-β-phenylcinnamate, 0
-benzotriazolylphenol, 0-benzotriazolyl-p-chlorophenol, 0-benzotriazolyl-2,4-di-1-butylphenol, O-benzotriazolyl-2,4-di-t- and octylphenol.

Water-resistant agents include water-soluble initial condensates such as N-methylol urea, N-methylol melamine, and urea-formalin;
Examples include blend heat treatment of dialdehyde compounds such as glyoxal and glutaraldehyde, inorganic crosslinking agents such as boric acid and borax, polyacrylic acid, methyl vinyl ether-maleic acid copolymer, isobutylene-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, methylcellulose, carboxymethylcellulose, hydroxymethylcellulose, gelatins, gum arabic, casein, styrene-maleic acid copolymer hydrolyzate, Water-soluble polymers such as styrene-maleic acid copolymer half ester hydrolyzate, isobutylene-maleic anhydride copolymer hydrolyzate, polyacrylamide derivatives, polyvinylpyrrolidone, polystyrene sodium sulfonate, sodium alginate, and styrene-
Water-insoluble polymers such as butadiene rubber latex, acrylonitrile-butadiene rubber latex, methyl acrylate-butadiene rubber latex, and acetic acid vinyl emulsion are used.

In addition, pigments, metal soaps, waxes, waterproofing agents, etc. may be added to the protective layer for the purpose of improving matching properties with the thermal head.

Further, 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, G (
Sodium salts or ammonium salts such as n-hexyl)sulfosuccinic acid and di(2-ethylhexyl)sulfosuccinic acid are preferred, but anionic surfactants are effective.

The electrically conductive thermal paper is manufactured by the method described in, for example, Japanese Patent Application Laid-open No. 49-11344 and Japanese Patent Application Laid-Open No. 50-48930. Generally, a coating liquid containing a conductive substance, an electron-donating colorless dye, and an electron-accepting compound dispersed together with a binder is applied to a support such as paper, or a conductive substance is applied to the support to form a conductive layer. The electrically conductive thermal paper is manufactured by applying a coating liquid in which an electron-donating colorless dye, an electron-accepting compound, and a binder are dispersed thereon. Note that the sensitivity can also be improved by using the thermofusible substance described above in combination.

The photosensitive pressure sensitive paper is manufactured by the method described in, for example, Japanese Patent Application Laid-open No. 179836/1983. In general, photopolymerization initiators such as silver iodobromide, silver bromide, silver behenate, Michler's ketone, benzoin derivatives, and benzophenone derivatives and crosslinking agents such as polyfunctional monomers such as polyallyl compounds, poly(meth)acrylates, and poly(meth)acrylamide is encapsulated in a synthetic resin capsule 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.

The electron-donating colorless dye according to the present invention is, for example, a compound of the formula (
III) A method of reacting a compound of formula (IV) with a compound of formula (V), or a method of reacting a compound of formula (V) with a compound of formula (IV)
It is produced by a method of reacting with a compound of formula (VI).

In addition, in the above formula, R1-R1, p-r, a-b and A represent the above-mentioned meanings.

The reaction shown above is carried out in the presence of a condensing agent such as acetic anhydride, sulfuric acid, or phosphorus oxychloride at a reaction temperature of 40 to 130°C.
It will be held for 10 hours.

Compounds of formula (DI) or (V) are generally obtained by reacting an anhydride of formula (■) with a compound of formula (VI) or (TV).

In this case, the reaction is preferably carried out in an organic solvent such as methylene chloride, ethylene chloride, toluene, chlorobenzene, acetonitrile, acetic acid, etc. at a reaction temperature of -10 to 100°C.
It will be held for 0 hours. At this time, a Lewis acid such as aluminum chloride or zinc chloride may be present.

Synthesis Example 1 0.1 mol of the compound of Example (3) was placed in a three-bottle flask equipped with a stirrer.
.

Weigh out 0.1rnol of chloroform and 30M1 of chloroform, and while stirring at an internal temperature of 40°C, add 0.3ml of phosphorus oxychloride.
Add mol. Stir under reflux for 3 hours. Chloroform and excess phosphorus oxychloride are distilled off under reduced pressure, and aqueous sodium hydroxide solution is added to the reaction mixture to make it alkaline. The reaction mixture is purified on a silica gel column using chloroform-ethyl acetate to obtain the desired product with a melting point of 91-93°C.

(Examples of the Invention) Examples are shown below, but the present invention is not limited thereto. % represents weight % unless otherwise specified.

(Example 1) 20 g each of the compound of Specific Example (3), bisphenol A which is an electron-accepting compound, and t-p-ethoxyphenoxy-2-p-chlorophenoxyethane which is a thermofusible substance.
A long 5% polyvinyl alcohol (Cl-PVA)
105) Each dispersion was obtained by dispersing with an aqueous solution in a ball mill all day and night to reduce the volume average particle size to 1.5 μm or less. Further, 80 g of calcium carbonate was dispersed with 160 g of a 0.5% solution of sodium hexametaphosphate using a homogenizer to obtain a pigment dispersion.

Each of the dispersions prepared above was mixed in a ratio of 5 g of an electron-donating colorless dye dispersion, 10 g of an electron-accepting compound dispersion, 10 g of a thermofusible substance dispersion, and 15 g of a material dispersion, and further added with 21% stearin. A heat-sensitive coating liquid was obtained by adding 3 g of a zinc acid emulsion.

This coating liquid was applied to high-quality paper using a coating bar so that the dry weight of the coating layer was 5 g/m'', and the coating was heated at 50°C.
After drying for 1 minute, a super calender was applied to obtain thermal recording paper.

The obtained thermal recording paper was free from fog during raw storage and had excellent stability over time.

Thermal recording paper was heated using a thermal head manufactured by Kyocera Corporation (KLT-
216-8MPDI) and 100kg/just before the head.
A blue image was obtained by printing with a pulse width of 1.0 while using a pressure roll with a head voltage of 24 V and a pulse cycle of I Oms in a thermal printing experimental apparatus having a CRL pressure roll. This colored image had absorption in the near-infrared region. Moreover, the obtained colored image showed good resistance to chemicals, sunlight, etc.

(Examples 2 to 4) In place of the electron-donating colorless dye and electron-accepting compound of Example 1, the following were used, respectively. A coated paper was obtained in the same manner as in Example 1 in other respects.

Example 2 Electron-donating colorless dye: Compound log of specific example (4), 2
-Anilino 3-methyl-6-N,N-dibutylaminofluorane] Og Electron-accepting compound bis(4-hydroxyphenyl)sulfone 5g 10 Danzinc benzimidazole complex 15
g Example 3 Electron-donating colorless dye: Compound 10g12 of specific example (7)
-Methyl-6-(4-(N-(4-N.

N-dimethylaminophenyl)amino)anilino)fluorane 10g Electron-accepting compound: 1,1-bis(4-hydroxyphenyl)cyclohexane 8g 14-β-p-methoxyphenoxyethoxysalicylate Zinc 8g 10 Danzinc 1-
4 g of phenyl-2,3-dimethyl-3-pyrazolin-5-one complex, Example 4 Electron-donating colorless dye: 10 g of the compound of Example (9), 2
-anilino-3-methyl-6-N-ethyl-N-isoamylaminofluorane 6g 13°6°-bisdiethylamino-5-diethylaminospiro(isobenzofuran-
1,9'-fluorene)-3-one 4 g Electron-accepting compound dibisphenol A 10 g.

10 g of acetylacetone complex of molybdic acid Example 2~
In all cases of No. 4, the obtained colored images had absorption in the near-infrared region and exhibited good resistance to chemicals, sunlight, and the like.

Claims (1)

[Claims] In a recording material that utilizes color development due to contact between an electron-donating colorless dye and an electron-accepting compound, a p-(p-substituted aminophenyl)aminophenyl indolyl phthalide compound is used as the electron-donating colorless dye. Recording material characterized by