JPS63151479A - 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 a diarylamino group having a substituted amino group at the 2-position thereof and xanthene having a substituted amino group at the 6-position thereof as partial skeletals 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 B10 are a hydrogen atom, an alkyl group or a halogen atom, R4 and R5 are a hydrogen atom, an alkyl group or an aryl group, R6, R7, R8 and R9 are a hydrogen atom, an aryl group, an alkoxy group, an alkyl group, a substituted amino 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 alkoxy group, an aryl group, a 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 present invention relates to a recording material, and in particular, a recording material having a color-forming portion absorbing light in the near-infrared region and having improved color-forming properties, shelf life, and stability of colored 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, UK patent 2140449, US patent 44800
52, 4436920, Special Publication No. 60-23.922,
Unexamined Japanese Patent Publication No. 57-179,836, No. 60-123.556
, 6G-123,557, etc.

The performance that a recording material should have is (11) sufficient color density and color development sensitivity, (2) no capri, (3) sufficient fastness of the color material after color development, (
4) Appropriate color hue and compatible with copying machine (5) S
/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 drawbacks such as fogging due to solvents and the like, and discoloration and fading of coloring bodies due to oils, fats, chemicals, etc. Therefore, water-based ink pens, oil-based ink pens, fluorescent pens, 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,
Pursuing the development of good materials for recording materials and recording materials by focusing on characteristics such as solubility in water, partition coefficient, polarity of pKa substituents, position of substituents, and changes in crystalline solubility when mixed. I've done it. Furthermore, in recent years, there has been a desire to develop recording materials that absorb in the near-infrared region.

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

(Structure of the Invention) The object of the present invention is to provide an electron-donating colorless dye and an electron-accepting compound having a diarylamino group having a substituted amino group at the 2-position and a xanthene having a substituted amino group at the 6-position as a partial skeleton. This was achieved using recording materials that are characterized by

Among the electron-donating colorless dyes according to the present invention, those represented by the following general formula (1) are preferred.

(In formula (1), R1 and R1 represent an alkyl group having 1 to 10 carbon atoms, R1 and Ro represent a hydrogen atom, an alkyl group, or a halogen atom, and R4 and Rs represent a hydrogen atom, an alkyl group, or an aryl group. , Rh, Ry, RII, R9 are hydrogen atoms, aryl groups, alkoxy groups, alkyl groups, substituted amino groups, or halogen atoms; ilA is benzene ring, naphthalene ring, or petero ring; sRs, R9 and Rh, R? may be bonded to each other to form a ring.) In the above general formula (1), R1 and R2, R4, R3,
And R4 and R6 may be bonded to each other to form a ring, and these may further have a substituent.

In addition, the oryl group represents a phenyl group, 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, and a substituted carbamoyl group. basis,
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 R1 or R2 in the above, an alkyl group having 1 to 10 carbon atoms, an alkoxyalkyl group,
Preferred are halogen-substituted alkyl groups, aryloxyalkyl groups, and phenyl groups that may have substituents,
Among the substituents represented by R4 or R3, a hydrogen atom, an aryl group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, or an alkyl group which may have a halogen atom as a substituent, and a carbon number 6 ~100 alkyl groups.

An alkoxy group, a substituted amino group, or a phenyl group which may have a halogen atom as a substituent is preferable.
1. Among the substituents represented by R6 and R9, a hydrogen atom,
Preferred are alkyl groups having 1 to 10 carbon atoms, alkoxy groups, dialkylamino groups, anilino groups and halogen atoms.

Ring A is preferably a benzene ring or a pyridine ring.

Examples of these electron-donating colorless dyes are shown below.

(representing N (CJs) z, etc.), etc., and these can be used alone, but two or more types can be mixed for tone adjustment and prevention of color fading of colored images.

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, fluorene-based compounds, and spiropyran-based compounds.

Specific examples of phthalides are given in U.S. Reissue Patent Specification No. 23.0.
No. 24, U.S. Patent No. 3.491.111, U.S. Patent 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
62.828 and 3,681,390, U.S. Pat. No. 3,920,510, 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 Pat. No. 4,246,318. Specific examples of fluorene compounds are described in Japanese Patent Application No. 61-240989.

Among the electron-accepting compounds according to the present invention, the following general formula (I[
) to (V) are preferred.

In the above general formula (n), R3 and R may be the same or different, and include a hydrogen atom, an alkyl group, an alkoxy group,
R5 represents a hydrogen atom or a group represented by the following general formula (Vl);

K! In the above formula -(Vl), R1 and R2 are the general formula (n
), and R1 represents a divalent group having 1 to 12 carbon atoms or Sot.

In the compound represented by the above general formula (n), when R1-H, R3 and R8 are a hydrogen atom or an alkoxycarbonyl group, and when %R3 is a group represented by the general formula (VI), R
1 is an alkylene group having 3 to 12 carbon atoms, 5 carbon atoms
-7 cycloalkylene group, C8-12 aralkylene group and SO! It is preferable that

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. 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-hydroxyphenyl sulfone, hexyl-4-hydroxybenzoate, 2,2'-dihydroxybiphenyl, 2.2-1:''s(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'-5ec-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(6tert-butyl-3-methylphenol),
4.4'-dihydroxydiphenyl sulfone, hydroquinone monobenzyl ether, 4-hydroxybenzophenone, 2,4-dihydroxybenzophenone, polyvinylpenzyloxyphenol, 2,4.4
'-) dihydroxybenzophenone, 2.2', 4.4
'-tetrahydroxybenzophenone, dimethyl 4-hydroxyphthalate, methyl 4-hydroxybenzoate,
2゜4.4'-)rihydroxydiphenylsulfone, 1
．． 5-bis-p-hydroxyphenylpentane, 1.6
-bis-p-hydroxyphenoxyhexane, tolyl 4-hydroxybenzoate, 4-hydroxybenzoic acid α-phenylbenzyl ester, phenylpropyl 4-hydroxybenzoate, phenethyl 4-hydroxybenzoate, 4
-Hydroxybenzoic acid p-chlorobenzyl, 4-hydroxybenzoic acid p-methoxybenzyl, 4-hydroxybenzoic acid benzyl ester, 4-hydroxybenzoic acid m-chlorozenzyl ester, 4-hydroxybenzoic acid β-phenethyl ester , 4-hydroxy-2', 4
'-Dimethyldiphenylsulfone, β-phenethylorselinate, cinnamyl oliselinate, orcelic acid-〇-chlorophenoxyethyl ester, 〇-ethylphenoxyethyl orselinate, O-phenylphenoxyethyl orselinate, m-phenyl Phenoxyethyl 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- Examples include p-methylbenzyl ester, 2,4-dihydroxybenzoic acid-β-phenoxyethyl ester, 2,4-dihydroxy-6-methylbenzoic acid benzyl ester, and methyl bis-4-hydroxyphenylacetate.

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; may be bonded to each other to form a ring.

Note that the alkyl group represents a saturated or unsaturated alkyl group or a 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. The teril group may also be a phenyl group,
Represents 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, a substituted amino group, a substituted oxycarbonyl group, a substituted It may have a substituent such as an oxysulfonyl group, a thioalkoxy group, an oxysulfonyl group, or a phenyl group.

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 is preferably a compound having a total number of carbon atoms of 14 or more, particularly preferably 16 or more from the viewpoint of water insolubility, and these may be used in the form of a metal salt,
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-pencudecylsalicylic 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-ethoxyphenoxyethoxysa IJ, thylic acid,
4-β-m-)lyloxyethoxysalicylic acid, 4-β
-o-)lyloxyethoxysalicylic acid, 4-(8-phenoxyoctyloxy)salicylic acid, and the like.

In the above formula, R represents a hydrogen atom, an aryl 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
is 0. Represents l 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) z Z n (A) z (V)
In the above formula, R is a monodentate or polydentate colorless organic ligand bonded to a zinc ion to form a complex via a heteroatom, and A is SCN, CI, or benzoic acid having an electron-withdrawing group. Represents an acid anion.

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,
Specific examples include imidazole complexes of rhodan zinc, which may be substituted with amino groups, formyl groups, vinyl groups, etc.
2-phenylimidazole complex, picoline complex, pyridine complex, 2-benzylimidazole complex, benzimidazole complex, 2,3-dimethyl-1-phenyl-3-pyrazolin-5-one complex, 1-phenyl-2-methyl-
3-benzyl-3-pyrazolin-5-one complex, ■-phenyl-2-methyl-3-(2-ethylhexyl)-3
-pyrazolin-5-one complex, 1-phenyl-2-methyl-3-isopropyl-3-pyrazolin-5-one complex, -phenyl-2,3-benzyl-pyrazolin-5-onetH4c, -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-accepting compounds 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 have a particle size of 10 μm or less, preferably 3 μm or less, in the dispersion medium.
It is used after being crushed and dispersed to a particle size of μ or less. As a dispersion medium, a water-soluble polymer aqueous solution with a concentration of about 0.5 to 10% is generally used, and dispersion is carried out using a ball mill, sand mill,
This is done using a horizontal sand mill, attritor, colloid mill, etc.

The ratio by weight of the electron-donating colorless dye to the electron-accepting compound used is preferably between 1=10 and 1:1, particularly preferably between 1:5 and 2:3; Separately from the 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 substance, the following general formula (■) ~
Examples include the compound represented by (11).

R5N1IC0NHz
(X)RaCONH-Ry
(ll) In the formula, R and ~R4 each represent a phenyl group, a benzyl group, and a lower alkyl or halogen substituted product thereof, and R3 and R6 each represent an alkyl group having 12 to 24 carbon atoms, an aryloxymethyl group, R1 represents a benzyl group, and R1 represents hydrogen or a phenyl group.

In addition, when the phenyl group or benzyl group represented by R3-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.
The above is 3 or less. When substituted with a halogen atom, fluorine is preferred. Also, formula (IX)
In, R6' represents hydrogen or a hydroxyl group.

(Xll) In the formula, A and B are oxygen atoms or sulfur atoms, R
o 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, and more preferably an alkylene group or an alkylene group having an ether bond. , also 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 -catalytic formulas (■) to (Xll) 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, benzyl p-benzyloxybenzoate (mp, 11
9°C), β-naftino t-benzyl ether (mp, 10
5°C), stearic acid amide (mp, 108°C), palmitic acid amide (mp, 103°C), N-phenylnialinic acid amide (fftp, 96°C), N-stearylurea (mp, 110°C), β - Naphthoic acid phenyl ester (mp, 92°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°C), α-naphthylbenzyl ether (mp, 76
°C), 1.4-butanediol-p-methylphenyl ether (mp, 93 °C), 1.4-propanediol-
p-methyl phenyl ether (mp, 93°C), stearamide (mp, 106-109°C) 1,4-butanediol-p-isopropylphenyl ether (m
p, 79°C), '1,4-butanediol-pt-octylphenyl ether (mp, 99°C), 2-phenoxy-1-p-tolyl-oxy-ethane (mp, 104
°C), 1-phenoxy-2-(4-ethylphenoxy)
Ethane (mp, 106°C), 1-phenoxy-2-
(4-chlorophenoxy)ethane (mp, 77°C), 1
．． 4-phytanediol phenyl ether (mp, 98
), diethylene glycol-bis(4-methoxy-phenyl) ether (mp, 101°C), p-ethylphenoxyacetic acid benzylamide (mp, 94°C), phenylacetic benzylamide (mp, 124°C), and the like.

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, more preferably 10 to 200% by weight, based on the electron accepting compound. The amount used is 20-150% by weight.

Additives that meet various requirements are further added to the coating liquid obtained by mixing the dispersion liquid thus obtained in an appropriate ratio.

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 purpose, fatty acids, metal soaps, etc. are added. Therefore, in addition to colorless dyes and electron-accepting compounds that contribute to color development, pigments, waxes, antistatic agents, ultraviolet absorbers, antifoaming agents, conductive agents, fluorescent dyes, surfactants, hindered phenol benzoic acid, etc. Additives such as derivatives are applied onto the support to constitute the recording material.

Specifically, pigments such as kaolin, calcined kaolin, talc, diatomaceous earth, aluminum hydroxide, magnesium hydroxide, calcined gypsum, silica, magnesium carbonate, titanium oxide, alumina, barium carbonate, barium sulfate, mica, and microballoons. , urea-formalin filler, 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, calcium stearate, and zinc oleate.

As a hindered phenol, 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-)lis(3-methyl-4-hydroxy-5-t-butylphenyl)butane , bis(2-hydroxy-3-t-7'thyl-5-methylphenyl)methane, bis(2-methyl-
Examples include 4-hydroxy-5-butylphenyl) sulfide.

These are dispersed and applied in a binder.

As the benzoic acid derivative, a benzoic acid metal salt 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 Examples include zinc salts, aluminum salts, cadmium salts, magnesium salts, calcium salts, etc. of carbamoylbenzoic acid, alkoxycarbonylbenzoic acid, substituted sulfamoylbenzoic acid, and the like. Particular preference is given to zinc salts, which 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/rrf.

Furthermore, a protective layer of about 0.2 to 24 μm consisting of a water-soluble or water-dispersible polymer compound such as polyvinyl alcohol, hydroxyethyl starch or epoxy-modified polyacrylamide and a crosslinking agent is provided on the coating surface layer to improve resistance. You can also do it.

When used in thermal paper, various embodiments described in 0L52228581, 0L2110854, Japanese Patent Publication No. 52-20142, etc. can be adopted. 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 6 g of 2-N-p-diethylaminophenylanilino-6-N-ethyl-N-isoamylaminofluorane, 2-anilino-3-chloro-6, which is an electron-donating colorless dye.
-8 g of dinithylaminofluorane and 2 g of 3',6'-bisdiethylamino-5-diethylaminospiro(isobenzofuran-1,9'-fluorene)-3'-one
, 20 g of zinc 4-β-p-methoxyphenoxyethoxysalicylate, which is an electron-accepting compound, 10 g of 2-benzyloxynaphthalene, and 15 g of stearic acid amide, which are heat-fusible substances, were each mixed with 100 g of 5% polyvinyl alcohol (Kuraray P VA105) It was dispersed with an aqueous solution in a ball mill overnight to give a volume average particle size of 3μ.

On the other hand, 80 g of a mixture of calcium carbonate and zinc oxide was dispersed using a homogenizer together with 160 g of a 0.5% solution of sodium hexametaphosphate.

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 high-quality paper weighing 50 g/nl, and the coating amount was 6
Apply with a wire bar so that g/rrr and heat at 50°C.
The coated paper was dried in an oven for 5 minutes and calendered to obtain a coated paper.

When color was developed using Fujitsu's high-speed facsimile FF-2000, a black printed image was obtained. This colored image had light absorption in the near-infrared region. Furthermore, when filter paper was impregnated with ethanol and castor oil and superimposed on the colored surface of the recording paper obtained by the above method, no fogging in the white area or decolorization (discoloration) in the colored area was observed. Ta.

On the other hand, the obtained coated paper was heated to a high temperature (60°C, 130%RH).
Although it was stored for 24 hours under humid conditions (40° C., 190% RH), almost no capri occurred.

Examples 2 and 3 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-bis(P-diethylaminophenyl)amino-6-dinithylaminofluorane 8g1
and 2-anilino-3-methyl-6-N-ethyl-N
-Isoamylaminofluorane 12g Electron-accepting compound @! J: 15 g of zinc 4-β-p-methoxyphenoxyethoxysalicylate and 1-phenyl-2,3-dimethyl-3-pyrazoline-5 of zinc rhodan
-one complex 5g Example 3 Electron-donating colorless dye: 2-N-p-anilinophenyl
8 g of anilino-6-dinithylaminofluoran, and 2-anilino-3-methyl-6-N-ethyl-N-isoamylaminofluoran 12-electron-accepting compound: 20 g of benzimidazole complex of rhodan zinc. It also had light absorption in the near-infrared region and had little fog.

Claims (1)

[Claims] A recording material characterized by containing an electron-donating colorless dye having as a partial skeleton a diarylamino group having a substituted amino group at the 2-position and a xanthene having a substituted amino group at the 6-position, and an electron-accepting compound.