JPS63153181A - Recording material - Google Patents

Abstract

PURPOSE:To provide a recording material having favorable color forming properties, raw preservability and stability of developed color images and showing light absorption in a near infrared region at a color-developed part, by providing a coated layer comprising a thiofluoran derivative having a substituent amino groups at 2-position and 6-position and an electron-acceptive compound. CONSTITUTION:A thiofluoran derivative is preferably one represented by general formula (I), wherein each of R<1>, R<2> and R<3> is hydrogen, a 1-10C alkyl or aryl, each of R<4> and R<5> is hydrogen, a halogen, 1-8C alkyl, alkoxyl or aryl, each of R<6> and R<7> is hydrogen, a halogen, 1-8C alkyl, amino, alkoxyl or aryl, and A is an arometic ring. An electron-acceptive compound is preferably one represented by any of general formulas (II)-(V). This recording material shows light absoption in a near infrared region at a color-developed part, has a sufficient developed color density, shows conspicuous stability of a color-developed coloring matter, and is substantially free of discoloration or fading even when being irradiated with light, heated or moistened for a long time.

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
, 60-123, 557, etc.

The performance that a recording material should have is (11) sufficient color density and color development sensitivity, (2) no fogging, (3) sufficient fastness of the color material after color development, (
4) Appropriate color hue and suitability for copying machine +515
/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, when it comes into contact with stationery and office supplies such as water-based ink pens, oil-based ink pens, K-light pens, ink ink, adhesives, glue, diazo developer, etc., or cosmetics such as hand creams and milky lotions, the white parts may become colored or the colored parts may become colored. However, the present inventors investigated the oil solubility, water solubility, partition coefficient, pKa substituent for each electron-donating colorless dye electron-accepting compound. We have pursued the development of good materials for recording materials and recording materials by focusing on characteristics such as polarity, position of substituents, and changes in crystalline solubility when mixed. 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 has been achieved by a recording material characterized by providing a coating layer containing a thiofluorane derivative having substituted amino groups at the 2- and 6-positions and an electron-accepting compound.

The thiofluorane derivative according to the present invention has the following general formula (+
) is preferred.

(In the formula, R', R"-, and R' are hydrogen atoms, and have 1 to 1 carbon atoms.
0 alkyl group, aryl group is R3, R4 is hydrogen atom, halogen atom, alkyl group having 1 to 8 carbon atoms, alkoxy group, aryl group is R6, R7 is hydrogen atom, halogen atom, carbon number 1 to 8 atom (A represents an aromatic ring) In the above general formula (1), the alkyl groups represented by R-1RZ are bonded to each other to form a 5- to 7-membered ring. may have a ring or a heteroatom or an unsaturated bond.

Further, the aryl group represented by R1 and R1 may be substituted with an alkyl group, an alkoxy group, a halogen atom, or a substituted amino group.

When Rh and R1 represent an amino group, the amino group may be substituted with an alkyl group or aryl group having 1 to 8 carbon atoms, and the aryl group may be further substituted with a substituted amino group, such as monoethylamino , diethylamino, N-methyl-N-phenylamino, diphenylaminoanilino, p-anilinoanilino, 0-anilinoanilino, p-
Preferred examples include diethylaminoanilino, pp'-anilinoanilinoanilino, and the like.

A is a 5-membered or 6-membered aromatic ring which may contain a heteroatom, specifically a benzene ring, a naphthalene ring, a pyridine ring, a pyrimidine ring, a pyrazine ring, a pyran ring, a thiazole ring, an imidazole ring, Preferred are an oxazole ring, a pyrrole ring, a thiophene ring, a furan ring, a benzofuran ring, a quinoline ring, a benzothiophene ring, and the like.

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

7~, CH3CH3 C.Hsl, These may be used alone, but two or more may be mixed for tone adjustment and prevention of 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 listed in U.S. Reissued Patent Specification Column 23.0
No. 24, U.S. Pat. Specification Tube No. 3゜624.107, No. 3.62
No. 7,787, No. 3,641,011, No. 3, 4
No. 62.828 and No. 3,681,390, U.S. Patent Specification No. 3,920,510, U.S. Patent Specification No. 3,959.571, and specific examples of subirodipyrans are given in U.S. Patent Specification No. 3, No. 971.808, pyridine-based and pyrazine-based color-forming compounds are described in U.S. Patent No. 3,77
Specific examples of fluorenes are described in US Pat. No. 5,424 and US Pat. No. 3,853,869, US Pat.

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 (I[), R and R1 may be the same or different, and represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an arylsulfonyl group, an alkoxycarbonyl group, or a halogen atom, R1 represents a hydrogen atom or a group represented by the following general formula (Vl).

H In the above formula (Vl), R1 and R2 are the above general formula (n)
R+ represents the same as Rx, and R4 represents a divalent group having 1 to 12 carbon atoms or SO.

In the compound represented by the above general formula (■), when R1 and R2 are a hydrogen atom or an alkoxycarbonyl group in R, -H, and when R3 is a group represented by the general formula (VT), R
4 is an alkylene group having 3 to 12 carbon atoms, 5 carbon atoms
-7 cycloalkylene groups, C8-12 aralkylene groups and SOz are preferred.

In the above general formula, the alkyl group represents a saturated or unsaturated alkyl group or a cycloalkyl group, which has a substituent such as an alkyl group, an alkoxy group, an aryloxy group, a halogen atom, or a cyano group. You can leave it there. 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, I, 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(6-te
rt-butyl-3-methylphenol), 4.4'-dihydroxyphenylsulfone, hydroquinone monobenzyl ether, 4-hydroxybenzophenone, 2.4
-Hydroxyhensiphenone, polyvinylbenzyloxyphenol, 2,4.4'-)lyhydroxybenzophenone, 2.2',4.4'-tetrahydroxybenzophenone, dimethyl 4-hydroxyphthalate, 4 -Methyl hydroxybenzoate, 2゜4.4'-trihydroxydiphenylsulfone, 1.5-bis-p-hydroxyphenylpenkune, 1.6-bis-p-hydroxyphenoxyhexane 4-hydroxybenzoic acid tolyl, 4 -Hydroxybenzoic acid α-phenylbenzyl ester, 4-hydroxybenzoic acid phenylpropyl, 4-hydroxybenzoic acid phenethyl, 4-hydroxybenzoic acid p-chlorobenzyl, 4-hydroxybenzoic acid M-p-
Methoxybenzyl, 4-hydroxybenzoic acid benzyl ester, 4-hydroxybenzoic acid-m-chlorobenzyl ester, 4-hydroxybenzoic acid β-phenethyl ester, 4-hydroxy-2',4'-dimethyldiphenylsulfone, β-phenethyl Orselinate, cinnamyl orselinate, orselic acid-〇-chlorophenoxyethyl ester, 0-ethylphenoxyethyl orselinate, o-phenylphenoxyethyl orselinate, m-phenylphenoxyethyl orselinate, 2
．． 4-dihydroxybenzoic acid-β-3'-1-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-6-methylbenzoic acid benzyl ester, methyl bis-4-hydroxyphenylacetate, and the like.

H 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 a cycloalkyl group, and these include z*i 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 aryl group may have 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, thioalkoxy group, arylsulfonyl group or 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, 7-aryl group having 6 to 12 carbon atoms, aryloxy group having 6 to 16 carbon atoms, alkoxy group having 1 to 12 carbon atoms, halogen atom Or an alkoxycarbonyl group is preferred.

The salicyl #1 derivative according to the present invention is preferably a compound having a total number of carbon atoms of 14 or more from the viewpoint of water insolubility, particularly 16
The above are preferred, and these may be used in the form of metal salts, or they may be used in the presence of zinc oxide, for example, in the dispersion to cause salt formation, adsorption or metathesis 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-methylhensylphenyl)
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-)lyloxyethoxysalicylic acid, 4-β-0
-) lyloxyethoxysalicylic 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
is 0. Represents 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/L/, and magnesium salts such as 3-chloro-5-butylphenyl) sulfone.

(R)x Zn (A)*' (V)
In the above formula, R represents a monodentate or polydentate colorless organic ligand that is bonded to a zinc ion via a heteroatom to form a complex;
represents SCN, CI or a benzoate anion having an electron-withdrawing group.

Among the colorless organic ligands represented by R, pyridine, imidazole, quinoline, hendithiazole, benzimidazole, or antipyrine ligands are preferred, and these include alkyl groups, cyano groups, alkoxy groups, phenyl groups, amino groups, and formyl groups. , may be substituted with a vinyl group, etc. Specific examples include imidazole complexes of rhodan zinc;
2-phenylimidazole complex, picoline complex, pyridine complex, 2-benzylimidazole complex, benzimidazole complex, 2,3-dimethyl-1-phenyl-3-pyrazolin-5-one complex, l-phenyl-2-methyl-
3-benzyl-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 complex, 1-phenyl-2,3-dibenzyl-pyrazolin-5
-one complex, -phenyl-2-hensyl-3-methyl-pyrazolin-5-one complex, and the like.

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 coloring part that absorbs light in the near-infrared region, has a sufficient coloring density, and is extremely stable, and hardly changes even after long-term light irradiation, heating, and heating. Since it does not cause discoloration, it is particularly advantageous in terms of long-term preservation of records. 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 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. Further, a thermofusible substance can be contained in the thermosensitive coloring layer in order to improve its thermal responsiveness.

As examples of preferable thermofusible substances, the following formats (■) ~
Examples include compounds represented by (X■).

Ra NHCONHI (X)R
a C0NH-Rt (XI) In the formula, R1 to R4 each represent a phenyl group, a benzyl group, and a lower alkyl or halogen substituted product thereof,
R5-Ra each represents an alkyl group, an aryloxymethyl group, or a benzyl group having 12 to 24 carbon atoms, R? represents hydrogen or phenyl group.

In addition, when the phenyl group or benzyl group represented by Rl=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 (Iχ
), R1' represents hydrogen or a hydroxyl group.

X X' (X n) In the formula, A and B are oxygen atoms or sulfur atoms, R
8 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. , X again.

y, z, x', y', z' may be the same or different (,
Indicates a hydrogen atom, a halogen atom, an alkyloxycarbonyl group, and an aralkyloxycarbonyl group.

The compounds of the general formulas (■) to (XI) have a melting point of 70°C.
The melting point is preferably 80°C or more and 130°C or less, and more preferably 80°C or more and 130°C or less. Specifically, benzyl p-benzyloxybenzoate (mP, 11
9°C), β-naphthylbenzyl ether (mp, 10
5°C), stearic acid amide (mp, 108°C),
Palmitic acid amide (mp, 103°C), N-phenylnialinic acid amide (mp, 96°C), N-stearinurea (mp, 110°C), β-naphthoic acid phenyl ester (mp, 92°C) , l-hydroxy-2-naphthoic acid phenyl ester (mp, 92°C), β-naphthol (p-chlorobenzyl) ether (rrl, 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-methylphenyl ether (mp, 9
3°C), stearamide (mp, 106-109
°C), 1.4-butanediol-p-isopropylphenyl ether (mp, 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-phenoxo-2-(4-chlorophenoxy)ethane (mp, 77 °C), 1.4-7' tandiol phenyl ether (mp, 98 °C), diethylene glycol (4-methoxy-phenyl) ether (mp , 101'
c), p-ethylphenoxyacetic acid benzylamide (mp
.

94°C), phenylacetic acid hensylamide (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. The preferred weight amount is 20-150% by weight.

Additives are further added to the coating liquid obtained by mixing the thus obtained dispersion 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 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 phenols, benzoin, etc. Additives such as acid 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 stone, silica, magnesium carbonate, titanium oxide, alumina, barium carbonate, barium sulfate, mica, and microballoons. , urea-formalin filler, polyethylene particles, cellulose filler, etc. particle size 0
．． The thickness can be selected from micro to 15μ. Examples of waxes include paraffin wax, carboxy-modified paraffin wax, carnauba wax, microcrystalline wax, polyethylene wax, and higher fatty 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-tris(3-methyl-4-hydroxy-5-t-butylphenyl)butane, Bis(2-hydroxy-3-t-butyl-5-methylphenyl)methane, bis(2-methylco4
-hydroxy-5-t-butylphenyl) sulfide and the like.

These are dispersed and applied in a binder.

Preferred benzoic acid derivatives include metal salts of benzoic acid having one or more electron-withdrawing properties, specifically halogen monobenzoic acid, nitrobenzoic acid, cyanobenzoic acid, substituted sulfonylbenzoic acid, acylbenzoic acid, and substituted carbamoylbenzoic acid. , alkoxycarbonylbenzoic acid group, substituted sulfamoylbenzoic acid, zinc salts, aluminum salts, cadmium salts, magnesium salts, calcium salts, 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, pre-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/rd.

Furthermore, a protective layer of about 0.2 to 2 μm consisting of a water-soluble or water-dispersible polymer compound such as polyvinyl alcohol, hydroxyethyl starch or epoxy-modified polyacrylamide and a pre-linking agent is provided on the coated surface layer to improve resistance. You can also do it.

When used in thermal paper, various embodiments described in 0LS2228581, 0LS2110854, Japanese Patent Publication No. 52-20142, etc. can be adopted. Or preheat in advance, 1! Operations such as moistening or stretching of coated paper may also be added.

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

Example 1 10 g of 2-P-dibutylaminoanilino-6-diethylaminothiofluorane and 10 g of 2-o-chloroari-no-6-dibutylaminofluorane, which are electron-donating colorless dyes, and rhodan, which is an electron-accepting compound. 2. Zinc
3-dimethyl-1-phenyl-3-pyrazolin-5-one complex 20. 20 g of 2-benzyloxynaphthalene, which is a thermofusible substance, was dispersed in a ball mill overnight with 100 g of a 5% polyvinyl alcohol (Kuraray PVA105) aqueous solution to give a volume average particle size of 3 μm.

On the other hand, 80 g of a mixture of calcium chloride and zinc oxide was added to 0.0 g of sodium hexamecrylate. The mixture was dispersed using a homogenizer together with 160 g of a 5% solution.

Disperse each dispersion as described above: 5 g of the electron-donating colorless dye dispersion, 10 g of the ascus-capable compound dispersion, 5 g of the thermofusible substance dispersion, and 22 g of the calcium carbonate and zinc oxide dispersion.
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/rrl, and applied with a wire bar so that the coating amount was 6 g/rrl.
The coated paper was dried in the open air at 0° C. for 5 minutes and subjected to calender treatment to obtain a coated paper.

When color was developed using Fujitsu Ltd.'s high-speed facsimile FF-2000, an impression of black stripes 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, 30% RH) and multi-temperature (40° C., 90% RH) conditions for 24 hours, almost no capri prevention occurred.

Examples 2 to 4 Coated paper was obtained in the same manner as in Example 1, except that the following dyes were used in place of the electron-donating colorless dye in Example 1.

Example 2 2-p-diethylaminoanilino-6-diethylaminothiofluorane 20 g Example 3 2-p-anilinoanilino-6-diethylaminothiofluorane 2
0g Example 42-p-p'-anilinoanilinoanilino-6
-20 g of diethylaminofluorane Examples 5 to 9 Coated paper was obtained in the same manner as in Example 1, except that the following compounds were used in place of the electron-accepting compound in Example 1.

Example 5 3-benzyl-2-methyl- of rhodan zinc
1-Phenyl-3-pyrazolin-5-one complex Example 6 3-(2-ethylhexyl) of zinc rhodan
-2-Methyl-1-phenyl-3-pyrazolin-5-one complex Example 7 3-isopropyl-2-methyl-1-phenyl-3-virapurin-5-one complex of rhodan zinc Example 8 2 of rhodan zinc -benzyl-methyl-1-
Tuunyl-3-pyrazilin-5-one complex Example 9 Each of the 2,3-dibenzyl-1-phenyl-3-pyrazolin-5-one complex color-forming layers of rhodan zinc has light absorption in the near-infrared region. There were also fewer capris.

Claims (1)

[Claims] A recording material comprising a thiofluorane derivative having substituted amino groups at the 2-position and the 6-position and an electron-accepting compound.