JPS63151480A - Recording material - Google Patents

Abstract

PURPOSE:To enhance a color forming property, raw preservability and the stability of a developed color image, by containing an electron donating leuco dye having 2-substituted aminoanilino-6-substituted amino xanthene as a partial skeletal and an electron acceptive compound. CONSTITUTION:An electron donating leuco dye is pref. represented by formula (I) (wherein R1 and R2 are a 1-10C alkyl group, R3 and R6 are a hydrogen atom, an alkyl group or a halogen atom, R4 and R5 are a hydrogen atom, a 5C or more alkyl group or an aryl group, x, Y and Z are a hydrogen atom, an aryl group, an alkoxy group, a substituted amino group, an alkyl group or a halogen atom and a ring A is a benzene ring, a naphthalene ring or a heterocyclic ring). An electron acceptive compound is pref. represented by formula II(wherein R1 and R2 may be same or different and are a hydrogen atom, an alkyl group, an aloxy group, an aryl group, an arylsulfonyl group, an alkoxycarbonyl group or a halogen atom and R3 is a hydrogen atom or the like).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The recording material of the present invention particularly has a color-forming portion that absorbs light in the near-infrared region, and has improved color-forming property, storage life, and stability of color-formed images. This invention relates to a recording material using an electron-donating colorless dye and an electron-accepting compound.

(Prior Art) Recording materials using an electron-donating colorless dye and an electron-accepting compound are already well known as pressure-sensitive paper, heat-sensitive paper, light-sensitive pressure-sensitive paper, electrically conductive heat-sensitive recording paper, and the like.

For example, British patent 2140449, US crop patent 44800
52, 4436920, Special Publication No. 60-23,922,
Unexamined Japanese Patent Publication No. 57-179.836, No. 60-123.556
, 60-123.557, etc.

The recording materials must have sufficient +11 color density and color development sensitivity, (2) do not cause capri, (3) have sufficient fastness of the color body after color development, (
4) Appropriate color hue and suitability for copying machine +513
/N ratio should be high, and (6) the color former should have sufficient chemical resistance, but currently there is no product that completely satisfies these requirements.

In particular, heat-sensitive recording materials have the disadvantage that capri is caused by solvents and the like, and the color formers are discolored and faded by oils, fats, chemicals, and the like. Therefore, water-based ink pens, oil-based ink pens, fluorescent pens, vermilion ink, adhesives,
When it comes into contact with stationery and office supplies such as glue and diazo developer, or cosmetics such as hand cream and emulsion, the white parts develop color or the colored parts change color and fade, significantly reducing the product value. The present inventors have investigated the oil solubility,
We are pursuing the development of good materials for recording materials and recording materials, focusing on characteristics such as solubility in water, partition coefficient, polarity of pKa substituents, position of substituents, and changes in crystalline solubility when mixed. Ta. Furthermore, in recent years, there has been a desire to develop recording materials that absorb in the near-infrared region.

(Object of the Invention) Therefore, an object of the present invention is to provide a recording material which has good color development properties, shelf life, and stability of colored images, and in which the color development portion absorbs light in the near-infrared region4.

(Structure of the Invention) The object of the present invention has been achieved by a recording material characterized by containing an electron-donating colorless dye having a 2-substituted aminoanilino-64-substituted aminoxanthene as a partial skeleton and an electron-accepting compound.

The electron-donating colorless dye according to the present invention has the following general formula (1):
Those represented by are preferred.

(In the formula, R,,R, represents an alkyl group having 1 to 10 carbon atoms, R
1, R & is a hydrogen atom, an alkyl group or a halogen atom, R4, Rs is a hydrogen atom, an alkyl group or an aryl group having 5 or more carbon atoms, x, y, z are hydrogen atoms,
Ring A represents a benzene ring, naphthalene ring or heterocycle, and Y and Z may be bonded to each other to form a ring. ) In the above general formula (1), R, and Rt
, R< and Y and R% and R4 may form a ring and may further have a substituent.

The aryl group represents a phenyl group, a naphthyl group, or a heteroaromatic ring group, and these include an alkyl group, an alkoxy group, an aryloxy group, a halogen atom, a nitro group, a cyano group, a substituted carbamoyl group, a substituted sulfamoyl group,
The alkyl group may have a substituent such as a substituted amino group, a substituted oxycarbonyl group, or a substituted oxysulfonyl group, and the alkyl group represents a saturated or unsaturated alkyl group or a cycloalkyl group. It may have a substituent such as a group, an aryloxy group, a halogen atom, or a cyano group.

Among the substituents represented by R7 or R2 in the above formula, alkyl groups having 1 to 10 carbon atoms, alkoxyalkyl groups, halogens, substituted alkyl groups and aryloxyalkyl groups are preferable, and among the substituents represented by R4 or Rs Hydrogen atom, an alkyl group having 5 to 12 carbon atoms, an alkoxy group, an aryloxy group, or an alkyl group which may have a halogen atom as a substituent, and 6 carbon atoms
A phenyl group which may have ~10 alkyl groups, alkoxy groups, substituted amino groups, or halogen atoms as substituents is preferred, and among the substituents represented by R1, hydrogen atoms, alkyl groups having 1 to 4 carbon atoms and a halogen atom are preferred, and among the substituents represented by R, a hydrogen atom and an alkyl group having 1 to 4 carbon atoms are preferred;
Ring A is preferably a benzene ring.

Examples of these colorless to light-colored electron-donating dye precursors include, but are not limited to, the following compounds.

2-p-cyamylaminoanilino-3-methyl-6-diethylaminofluorane, 2-p-cyamylaminoanilino-6-diethylaminofluorane, 2-p-dioctylaminoanilino-3-methyl-6 -thioctylaminofluorane, 2-p-dioctylaminoanilino-6
-diethylaminofluorane, 2-p-cyamylaminoanilino-6-N-methyl-N-dichlorohexylaminofluorane, 2-p-cyamylaminoanilino-3-chloro-6-diethylaminofluorane, 2 -N-ethyl-p-cyamylaminoanilino-6-N-ethyl-N-
Isoamylaminofluorane, 2-m-cyamylaminoanilino-6-N-methyl-N-isoamylaminofluorane, 2-1)-anilinoanilino'-6-dinithylaminofluorane, 2-p-anilinoanilino- 3-chloro-6-N-ethyl-N-isoamylaminofluorane, 2-p-anilinoanilino-6-N-isobutyl-
N-ethylaminofluorane, 2-N-ethylanilinoanilino-6-N-ethyl-N-isoamyl 7minofluorane, 2-p-N-ethylanilinoanilino-6-N
-Methyl-N-cyclohexylaminofluorane, 2-
p-N-ethylanilinoanilino-6-diethylaminofluorane, 2-(p-4-anilinoanilino)anilino-6-diethylaminofluorane, 2-(p-4-
Anilinoanilino)anilino-3-methyl-6-diethylaminofluorane, 2-p-(p-diethylaminoanilino)anilino-6-diethylaminofluorane, 2
-p-(p-diethylaminoanilino)anilino-3-
Examples include methyl-6-N-isoamyl-N-ethylaminofluorane, 2-1)-(p-dibutylaminoanilino)anilino-6-diethylaminofluorane, and these can be used alone, but , Two or more kinds may be mixed for color ByHB5 adjustment and prevention of color fading of a colored image.

These electron-donating colorless dyes include other triphenylmethane phthalide compounds, fluoran compounds, phenothiazine compounds, indolyl phthalide compounds, leucoolamine compounds, rhodamine lactam compounds, triphenylmethane compounds, and triazenes. It may be used in combination with various compounds such as fluorine-based compounds, spiropyran-based compounds, and fluorene-based compounds.

Specific examples of phthalides are given in U.S. Reissue Patent Specification No. 23,0.
No. 24, U.S. Pat. No. 3,491,111, U.S. Pat. No. 3,491.112, U.S. Pat. Specification No. 3,624,107, Specification No. 3.62
No. 7,787, No. 3,641,011, No. 3, 4
No. 62.828 and No. 3,681,390, U.S. Pat. No. 3.920.5LO, U.S. Pat. .971,808; pyridine-based and pyrazine-based color-forming compounds are described in U.S. Patent No. 3,775;
．． No. 424 and No. 3,853,869, and US Patent No. 4,246,318.

Among the electron-accepting compounds according to the present invention, the following general formula (n)
Those represented by ~(V) are preferred.

In the above general formula (n), R and R□ may be the same or different, and include a hydrogen atom, an alkyl group, an alkoxy group,
R1 represents a hydrogen atom or a group represented by the following general formula (Vl);

In the above formula (Vl), R6 and Ro are the general formula (I[
), and R4 represents a divalent group having 1 to 12 carbon atoms or Sot.

In the compound represented by the above general formula (n), in R1-H, R1 and R2 are a hydrogen atom or an alkoxycarbonyl group, and when R4 is a group represented by the general formula (VI), R
4 is an alkylene group having 3 to 12 carbon atoms, 5 carbon atoms
-7 cycloalkylene groups, C8-12 aralkylene groups and SO2 are preferred.

In the above general formula, the alkyl group represents a saturated or unsaturated alkyl group or a cycloalkyl group, and these may have a substituent such as an aryl group, an alkoxy group, an aryloxy group, a halogen atom, or a cyano group. good. Some examples include 4-phenylphenol, bisphenol sulfone, p-phenylsulfonylphenol, p-tolylsulfonylphenol, bis(3-vinyl-4-hydroxyphenyl)sulfone, 2.2-bis(3-vinyl- 4-hydroxyphenyl)propane, bis-3-allyl-4-hydroxyphenylsulfone, hexyl-4-hydroxybenzoate, 2,2'-dihydroxybiphenyl, 2,2-bis(4-hydroxyphenyl)propane, 4-4 '-isopylidene bis(2
-methylphenol), 1,1-bis-(3-chloro-
4-hydroxyphenyl)cyclohexane, 1.1-bis(3-chloro-4-hydroxyphenyl)=2-ethylbutane, 4.4′-secondary-isooctylidene diphenol, 4+ 4′-5ee-butylidene diphenol, 4-p-methylphenylphenol, 4,
4'-isopentylidene diphenol, 4,4'-methylcyclohexylidene diphenol, 4,4'-dihydroxydiphenyl sulfide, 1,4-bis-(4'
-hydroxycumyl)benzene, 1,3-bis(4'-
hydroxycumyl)benzene, 4,4'thiobis(6t
ert-butyl-3-methylphenol), 4゜4゛-
Dihydroxydiphenyl sulfone, hydroquinone monobenzyl ether, 4-hydroxybenzophenone, 2
．． 4-dihydroxybenzophenone, polyvinylbenzyloxycarbonylphenol, 2,4.4'-)dihydroxybenzophenone, 2.2',4.4''-tetrahydroxybenzophenone, dimethyl 4-hydroxyphthalate, methyl 4-hydroxybenzoate, 2,4°4'
-trihydroxydiphenylsulfone, 1゜5-bis-
p-hydroxyphenylpentane, 1゜6-bis-p-
Hydroxyphenoxyhexane, tolyl 4-hydroxybenzoate, 4-hydroxybenzoaα-phenylbenzyl ester, phenylpropyl 4-hydroxybenzoate, phenethyl 4-hydroxybenzoate, p-chlorobenzyl 4-hydroxybenzoate, 4-hydroxy p-methoxybenzyl benzoate, 4-hydroxybenzoic acid benzyl ester, 4-hydroxybenzoic acid m-') lolobenzyl ester, 4-hydroxybenzoic acid β-phenethyl ester, 4-hydroxy-2',4'- Dimethyl diphenyl sulfone, β-phenethylorselinate, cinnamyl oliselinate, orcelic acid-〇-chlorophenoxyethyl ester, 0-ethylphenoxyethyl orselinate, 0-ethylphenoxyethyl orselinate, m-phenylphenoxyethyl Orcelinate, 2,4-dihydroxybenzoic acid-β-3'-t-
butyl-4'-hydroxyphenoxyethyl ester,
1-t-butyl-4-p-hydroxyphenylsulfonyloxybenzene, 4-N-benzylsulfamoylphenol, 2゜4-dihydroxybenzoic acid-p-methylbenzyl ester, 2,4-dihydroxybenzoic acid-β
-Phenoxyethyl ester, 2,4-dihydroxy-
Examples include benzyl 6-methylbenzoate, methyl bis-4-hydroxyphenylacetate, and the like.

In the above formula, R represents a hydrogen atom, an aryl group or an alkyl group, X represents an alkyl group, an alkoxy group or a halogen atom, M represents an n-valent metal atom, and n represents an integer of 1 to 3.

Note that the alkyl group represents a saturated or unsaturated alkyl group or cycloalkyl group, which has a substituent such as an aryl group, an alkoxy group, an aryloxy group, a halogen atom, an acylamino group, an aminocarbonyl group, or a cyano group. Also, the aryl group may be a phenyl group,
Represents a naphthyl group or a heteroaromatic group, and these include an alkyl group, an alkoxy 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, a thioalkoxy group, a substituted oxysulfonyl group, a phenyl group, etc.
It may have.

Among the substituents represented by R in the above formula, hydrogen atoms, phenyl groups, and alkyl groups having 1 to 22 carbon atoms are preferred,
Among the substituents represented by Magnesium and calcium are preferred.

Among the substituents of the alkyl group and alkoxy group represented by X, an aryl group having 6 to 12 carbon atoms, an aryloxy group having 6 to 16 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a halogen atom, An alkoxycarbonyl group is preferred.

The salicylic acid derivative according to the present invention preferably has a total number of carbon atoms of 14 or more, particularly preferably 16 or more, from the viewpoint of water insolubility. These may be used in the form of metal salts,
It is also possible to use zinc oxide, for example, present in the dispersion to cause salt formation, adsorption or double decomposition in the dispersion. Next, a specific example will be shown.

4-pentadecylsalicylic acid, 3-phenylsalicylic acid, 3-cyclohexylsalicylic acid, 3゜5-di-t-butylsalicylic acid, 3,5-di-dodecylsalicylic acid, 3
-Methyl-5-benzylsalicylic acid, 3-phenyl-5
-(α,α-dimethylbenzyl)salicylic acid, 3,5-
Di(α-methylbenzyl)salicylic acid, 3,5-di-t
-Octylsalicylic acid, 5-tetradecylsalicylic acid,
5-hexadecylsalicylic acid, 5-octadecylsalicylic acid, 5-α-(p-α-methylbenzylphenyl)ethylsalicylic acid, 4-dodecyloxysalicylic acid, 4-
Tetradecyloxysalicylic acid, 4-hexadecyloxysalicylic acid, 4-β-phenoxyethoxysalicylic acid, 4-β-p-tolyloxyethoxysalicylic acid, 4-
β-p-ethylphenoxyethoxysalicylic acid, 4-β
-p-methoxyphenoxyethoxysalicylic acid, 4-β
-p-ethoxyphenoxyethoxysalicylic acid, 4-β
-m-Tolyloxyethoxysalicylic acid, 4-β-〇-
tolyloxyethoxysalicylic acid, 4-(8-phenoxyoctyloxy)salicylic acid, etc.

In the above formula, R represents a hydrogen atom, an alkyl group, an alkyl group, or a halogen atom, X represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom, M represents a divalent metal, and n represents 0 .1 or 2.

Specific examples include bis(2-hydroxy-5-butylphenyl)sulfone, bis(2-hydroxy-5-phenylphenyl)sulfone, bis(2-hydroxy-5-octylphenyl)sulfone, bis(2-hydroxy- 5
-chlorophenyl)sulfone, bis(2-hydroxy-
Examples include zinc, nickel, and magnesium salts such as 3-chloro-5-butylphenyl) sulfone.

(R) 2 Z n (A) 2 (V)
In the above formula, R is a monodentate or polydentate colorless organic ligand that is bonded to a zinc ion via a heteroatom to form a complex,
A represents SCN, CA or a benzoic acid anion having an atom-attracting group.

Among the colorless organic ligands represented by R, pyridine, imidazole, quinoline, benzothiazole, benzimidazole, or antipyrine ligands are preferred, and these include alkyl groups, cyano groups, alkoxy groups, phenyl groups, amine groups, and formyl groups. , a vinyl group, etc. may be substituted.

Specific examples include imidazole complex of rhodan zinc, 2-
Phenylimidazole complex, picoline complex, pyridine complex, 2-hensylimidazole complex, benzimidazole complex, 2,3-dimethyl-1-phenyl-3-pyrazolin-5-one complex, 1-phenyl-2-methyl-3-
Hensyl-3-pyrazolin-5-one complex, 1-phenyl-2-methyl-3-(2-ethylhexyl)-3-pyrazolin-5-one complex, 1-phenyl-2-methyl-
3-isopropyl-3-pyrazolin-5-one ti form,
1-phenyl-2,3-dibenzyl-pyrazoline-5-
on complex, l-phenyl-2-benzyl-3-methyl-
Examples include pyrazolin-5-one complexes. These may be used alone or in combination. Among these, electron-accepting compounds consisting of salicylic acid derivatives and metal salts are preferred, and zinc salts are particularly preferred.

The recording material according to the present invention has a color-forming part that absorbs light in the near-infrared region, has a sufficient color density, and is extremely stable, with almost no discoloration or fading even with long-term light irradiation, heating, or humidification. This method is especially advantageous from the viewpoint of long-term preservation of records because it does not cause any damage. Furthermore, when used in a heat-sensitive recording material, there is no drawback that uncolored areas develop color due to solvents, etc., or color-forming bodies change color or fade due to oils, fats, chemicals, etc., so it has near-ideal performance as a recording material.

When used in thermal paper, the electron-donating colorless dye and the electron-accepting compound are generally pulverized and dispersed in a dispersion medium to a particle size of 10μ or less, preferably 3μ or less. A water-soluble polymer aqueous solution having a concentration of about 5 to 10% is used, and dispersion is carried out using a ball mill, a sand mill, a horizontal sand mill, an attritor, a colloid 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. On the other hand, separately from the electron-donating colorless dye and the electron-accepting compound, calcium carbonate and/or zinc oxide are pulverized and dispersed in a dispersion medium. The amount of calcium carbonate and/or zinc oxide used is preferably 0.5 to 20 times (weight ratio), particularly preferably 1 to 10 times the amount of the electron-accepting compound. A fusible substance can be included in the thermosensitive coloring layer.

As an example of a preferable thermofusible material, the following general formula (■) ~
Examples include compounds represented by (XI).

Rs N HCON Hz
(X)R,C0NH-R?
(XI) In the formula, R1 to R4 each represent a phenyl group, a benzyl group, or a lower alkyl or halogen substituted product thereof, and R3 and R1 each have a carbon number of 12
24 or less alkyl groups, aryloxymethyl groups,
R1 represents a benzyl group, and R1 represents hydrogen or a phenyl group.

In addition, when the phenyl group or benzyl group represented by RI=R4 in general formulas (■) to (XI) is substituted with a lower alkyl group, the number of carbon atoms is 1 or more and 8 or less, preferably 1 or more and 3 or less. . When substituted with a halogen atom, fluorine is preferred. Also, the formula (IX
), R4' represents hydrogen or a hydroxyl group.

Z Z ′(XI)
In the formula, A and B represent an oxygen atom or a sulfur atom, and R6 represents a divalent group, preferably an alkylene group, an alkylene group having a carbonyl group, an alkylene group having a halogen atom, an alkylene group having an unsaturated bond, More preferred are alkylene groups and alkylene groups having an ether bond. Further, x, y, z, X', Y', and Z' may be the same or different, and represent a hydrogen atom, a halogen atom, an alkyloxycarbonyl group, or an aralkyloxycarbonyl group.

The compounds of the general formulas (■) to (kari) preferably have a melting point of 70°C or more and 150°C or less, more preferably a melting point of 80°C or more and 130°C or less. Specifically, p
-Benzyloxybenzoate (mp, 119°C)
, β-naphthylbenzyl ether (mp, 105°C),
Stearic acid amide (m9.108°C), palmitic acid amide (mp, 103°C), N-phenylniaric acid amide (mp, 96°C), N-stearylurea (mp, 1
10°C), β-naphthoic acid phenyl ester (mp, 9
2°C), 1-hydroxy-2-naphthoic acid phenyl ester (mp, 92°C), β-naphthol (p-chlorobenzyl) ether (mp, 115°C), β-naphthol (p-methylbenzyl) ether (mp , 96℃), α
-naphthylbenzyl ether (mp, 76°C), 1.4
-butanediol-p-methylphenyl ether (mp
, 93°C), 1.4-propanediol-p-methylphenyl ether (mp, 93°C), stearic acid amide (mp, 106-109°C), 1° 4-butanediol-p-isopropylphenyl ether (mp , 79℃)
, 1,4-butane diol-pt-octylphenyl ether (mp.

99°C), 2-phenoxy-1-p-)lyluoxyethane (mp, 1 (14°C), l-phenoxy-2-(
4-ethylphenoxy)ethane (mp, 106°C), 1
-phenoxy-2-(4-chlorophenoxy)ethane (
mp, 77°C), 1,4-butanediol phenyl ether (mp, 98°C), diethylene glycol-bis(
4-methoxy-phenyl)ether (mp, 101'
C), P-ethylphenoxyacetic acid benzylamide (f
fkp, 94°C), phenylacetic benzylamide (mp
, 124°C).

The thermofusible substance may be used alone or in combination, and in order to obtain sufficient thermal responsiveness, it is preferably used in an amount of 10 to 200% by weight based on the electron-accepting compound. A more preferable usage amount is 20 to 150% by weight.

Additives may be added to the coating liquid prepared by mixing the dispersion thus obtained in an appropriate ratio 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 addition to colorless pigments and electron-accepting compounds that contribute to color development, pigments, waxes, antistatic agents, ultraviolet absorbers, antifoaming agents, conductive agents, fluorescent dyes, surfactants, hindered phenols, and benzoin are generally used. Additives such as acid derivatives are applied onto the support to constitute the recording material.

Specifically, kaolin as a pigment, calcined kaolin, tank, diatomaceous earth, aluminum hydroxide, magnesium hydroxide, calcined gypsum, silica, magnesium carbonate, titanium oxide, alumina, barium carbonate, barium sulfate, mica, microballoon. , urea-formalin Wyler, polyethylene particles, cellulose filler, etc. particle size 0
．． Selected from 1 to 15μ. Examples of waxes include paraffin wax, carboxy-modified paraffin wax, carnauba wax, microcrystalline wax, polyethylene wax, and higher fatty acid esters.

Examples of the metal soap include polyvalent metal salts of higher fatty acids, such as zinc stearate, aluminum stearate, potassium stearate, and zinc oleate.

Hinder and phenol are at least 2 or 6
Phenol derivatives in which one or more of the positions are substituted with a branched alkyl group are preferred.

For example, 1. 1-bis(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1゜1.3-tris(3-methyl-4-hydroxy-5-t-butylphenyl)butane, bis(2- Hydroxy-3-t-7'
Examples include methyl-5-methylphenyl)methane, bis(2-methyl-4-hydroxy-5-t-butylphenyl)sulfide, and the like.

These are dispersed and applied in a binder.

As the benzoic acid derivative, a metal salt of benzoic acid having one or more electron-withdrawing groups is preferable, and specifically, halogen-substituted benzoic acid, nitrobenzoic acid, cyanobenzoic acid, substituted sulfonylbenzoic acid, acyl benzoic acid, substituted carbamoyl benzoic acid, etc. Examples include zinc salts, aluminum salts, cadmium salts, magnesium salts, calcium salts, etc. of acid, alkoxycarbonylbenzoic acid, substituted sulfamoylbenzoic acid, and the like.

Particularly preferred are zinc salts. These can also be used as electron-accepting compounds. These are mixed with an electron-accepting compound or dispersed alone 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. Examples include copolymers, polyacrylic acid, polyacrylic acid amide, methylol-modified polyacrylamide, starch derivatives, casein, and gelatin. In addition, in order to impart water resistance to these binders, water-resistant agents (gelling agents, cross-linking agents) are added, or emulsions of hydrophobic polymers, specifically styrene-butadiene rubber latex, acrylic resin emulsions, etc. You can also add

The coating liquid is applied onto base paper, high-quality paper, synthetic paper, plastic sheet, or neutral paper at a rate of about 2 to 10 g/cd.

Furthermore, the coating surface layer is made of a water-soluble or water-dispersible polymer compound such as polyvinyl alcohol, hydroxyethyl starch or epoxy-modified polyacrylamide, and a crosslinking agent to maintain a coating thickness of about 0.2 to 2μ! ! A layer can also be provided to improve resistance.

When used for thermal paper, also OL 32228581
Various embodiments may be adopted, such as those described in Japanese Patent Publication No. 2110854 and Japanese Patent Publication No. 52-20142. Alternatively, operations such as preheating, humidity control, or stretching of coated paper may be added prior to recording.

(Examples of the Invention) Examples will be shown below, but the present invention is not limited only to these examples.

Example 1 Electron-donating colorless dye, 2-p-anilinoanilino-6-N-ethyl-N-isoamylaminofluorane 8
g, 8 g of 2-anilino-3-chloro-6-dinithylaminofluorane and 3'.

2 g of 6゛- and sudiethylamino-5-diethylaminospiro(isobenzofuran-1,9゛-fluorene)-3-one, 20 g of zinc 4-β-p-methoxyphenoxyethoxysalicylate, which is an electron-accepting compound, and thermofusible 10 g of 2-benzyloxynaphthalene and 15 g of stearic acid amide, which are chemical substances, were each dispersed with 100 g of a 5% polyvinyl alcohol (Kuraray PVA105) aqueous solution in a ball mill overnight to give a volume average particle size of 3 μm. Meanwhile, 80 g of a mixture of calcium carbonate and zinc oxide
0.5% of sodium hexametaphosphate was dispersed with 160 g of the liquid using a homogenizer.

After dispersing each dispersion as described above, 5 g of the electron-donating colorless dye dispersion, 10 g of the electron-accepting compound dispersion, 5 g of the thermofusible substance dispersion, and 22 g of the calcium carbonate and zinc oxide dispersion were prepared.
4 g of a zinc stearate emulsion and 5 g of a 2% aqueous solution of sodium (2-ethylhexyl)sulfosuccinate were added to obtain a coating liquid. This coating liquid was dried on a high-quality paper weighing 50 g/rd and applied with a wire bar so that the coating amount was 6 g/rrr.
The coated paper was dried in an oven at 50° C. for 5 minutes and calendered to obtain a coated paper.

When color was developed using Fujitsu High Speed Facsimile FF-2000, a black impression was obtained. This colored image had light absorption in the near-infrared region. In addition, when filter paper was impregnated with ethanol and castor oil and superimposed on the colored side of the recording paper obtained by the above method, no capri in the white area and no discoloration (discoloration or fading) in the colored area was observed. Ta.

On the other hand, when the obtained coated paper was stored under high temperature (60° C., 30% RH) and high humidity (40° C., 90% RH) conditions for 24 hours, almost no fogging occurred.

Examples 2 to 5 In place of the electron-donating colorless dye and electron-accepting compound in Example 1, the following were used, respectively. Coated paper was obtained in the same manner as in Example 1 except for the above.

Example 2 Electron-donating colorless dye: 2-p-cyamylaminoanilino-6-diethylaminofluorane 8g 12-anilino-
3-Methyl-6-N-ethyl-N-isoamylaminofluorane 8g 1 and 3'.

6'-bisdiethylamino-5-diethylaminospiro(isobenzofuran-1,9'-fluorene)-3-one 1g Electron-accepting compound: 1,4-bis(p-hydroxycumyl)benzene 10g, bis(2- 8 g of zinc salt of hydroxy-5-biphenyl) sulfone and 4 g of benzimidazole complex of zinc rhodan Example 3 Electron-donating colorless dye: 2-p-, (p-diethylaminoanilino)anilino-6-sibutylaminofluorane L
og, 2-anilino-3-methyl-6-N-ethyl-N
-isoamylaminofluorane 0 g Electron-accepting compound: 1.1 bis(4-hydroxyphenyl)cyclohexane 8 g 14-β-p-methoxyphenoxyethoxyethoxysalicylate zinc 8 g and rhodan zinc 1-phenyl-2,3-dimethyl-3 -pyrazoline-5
-one complex 4 g Example 4 Electron-donating colorless dye: 2-p-(p-anilinoanilino)anilino-6-cyptylaminofluoran 10 g, 2
-Anilino-3-chloro-6-diethylaminofluorane 10g Electron-accepting compound-Rhodan zinc imidazole complex 10
The color images of g1 and bisphenol sulfone 10g each had light absorption in the near-infrared region, and also had a small amount of capri.

Claims (1)

[Claims] A recording material characterized by containing an electron-donating colorless dye having 2-substituted aminoanilino-6-substituted aminoxanthene as a partial skeleton and an electron-accepting compound.