JPH01215577A - Recording material - Google Patents

Abstract

PURPOSE:To enhance color-forming properties and stabilities of coloring hue and coloring image, by providing a thermal recording layer containing an electron donative colorless dye shown by a specific formula and an electron accepting compound on a substrate. CONSTITUTION:An electron donative colorless dye shown by a formula I (where R1, R2 represents alkyl, R3 represents hydrogen, alkyl, and aryl, R4 represents alkyl and alkoxy, X represents hydrogen, alkyl, halogen, nitro, and substituted amino, (m) is an integer of 1-4, and a ring A is an aromatic ring having one or more nitrogen atom) and an electron accepting compound are dispersed in a binder. This dispersion is applied on a substrate and dried to form a thermal recording layer, and then a recording material is manufactured. In addition, as the electron accepting compound, a phenol derivative, a salicylic derivative, and the like can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a recording material, and particularly to a recording material with improved color hue, color development, and stability of color images.

(Prior art) Recording materials using electron-donating colorless dyes and electron-accepting compounds are already known as pressure-sensitive paper, thermal paper, photosensitive pressure-sensitive paper, current-carrying thermal recording paper, thermal transfer paper, etc. For example, British Patent No. 2140449, U.S. Patent No. 4480052, U.S. Patent No. 4436920, Japanese Patent Publication No. 60-23992, Japanese Unexamined Patent Publication No. 1989-57
-179836, 60-123556, 6-0-1
I am familiar with 23557 etc. - The performance that the recording material should have is (1) sufficient color density and color development sensitivity, C2) no fogging, (3) sufficient fastness of the color material after color development, (
4) Appropriate color hue and suitability for copying machines, (5)
The S/N ratio is high, (6) the color former has sufficient chemical resistance, and (7) it is easily soluble in organic solvents, but currently no product has been obtained that completely satisfies these requirements. .

Particularly in recent years, with the diversification of requirements for recording systems, research has been intensively conducted to improve these characteristics. Among these, the demand for (3) is especially strong for blue color recording materials.

Conventionally, diphenylmethane compounds, triphenylmethane compounds, phthalide compounds, leucomethylene blue compounds, and the like have been known as compounds that develop a blue to blue-purple color. However, each of these compounds has drawbacks.

For example, 3,3-bis(p-dimethylaminophenyl)
-6-Simethylaminophthalide (i.e., crystal violet lactone) develops quickly and exhibits a deep blue color, but
The lightfastness of the colored image is extremely poor. 3,7-bis(dimethylamino), a leucomethylene blue compound
-1O-benzoylphenothiazine (i.e., benzoyl leucomethylene blue) has a color image with extremely excellent light resistance, but has the disadvantage that color development is very slow and color development with organic color developers is very poor.

The present inventors have investigated the oil solubility, solubility in water, partition coefficient, pKa, polarity of substituent, position of substituent, crystallinity when mixed, for each of the electron donating colorless dye and the electron accepting compound. Focusing on characteristics such as changes in solubility, we have pursued the development of good materials for recording materials and recording materials.

(Object of the Invention) Therefore, the object of the present invention is to provide a recording material using a material that has good color development, color hue, and stability of color images, and also satisfies other necessary conditions.

(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 the electron-donating colorless dye is represented by the following general formula (I). This was achieved by means of a recording material characterized by the use of the represented compounds.

In the above formula, R+, R2 is an alkyl group, R5 is a hydrogen atom,
% alkyl group or aryl group R4 is an alkyl group, alkoxy group, X is a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a nitro group or a substituted amino group, m
represents an integer from 1 to 4, and ring A represents an aromatic ring having at least one nitrogen atom.

In addition, an alkyl group represents a saturated, unsaturated or cycloalkyl group, and these include a substituent such as an aryl group, an alkoxy group, an aryloxy group, an acyloxy group, a noherogen atom, an acylamino group, an aminocarbonyl group, or a cyano group. may have.

The aryl group represents a phenyl group, a naphthyl group, or a heterocyclic 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 sulfamoyl group. It may have a substituent such as an amino group, a substituted oxycarbonyl group, a substituted oxysulfonyl group, an alkylthio group, an arylsulfonyl group, or a phenyl group.

Among the substituents represented by R1 or R3 in the above formula, an alkyl group having 1 to 18 carbon atoms is preferred, and these include a halogen atom, an alkoxy group, and an aryl group.

may be substituted with a group, an aryloxy group, an alkyl group, an acyl group, a cyano group, a hydroxy group, a furfuryl group, etc.

R+SR2 is more preferably an alkyl group having 2 to 12 carbon atoms.

R+ SR2 may be bonded to each other to form a 5- to 8-membered ring such as piperidine, morpholine, pyrrolidine, piperazine, hexamethyleneimine, caprolactam, indole and the like.

Morpholino group, N-ethylpiperidino group, dimethylamino group, diethylamino group, dipropylamino group, dibutylamino group, N-ethyl-N-ynamylamino group, N
-ethyl-N-imbutylamino group, N-ethyl-N-
Examples include benzylamino group, siamylamino group, diacylamino group, dioctylamino group, N-ethyl-N-tetrahydrofurfurylamino group, and dibenzylamino group.

Among the substituents represented by R2 in the above formula, hydrogen atoms, alkyl groups having 1 to 18 carbon atoms, and aryl groups having 6 to 12 carbon atoms are preferred, and these include halogen atoms, alkoxy groups, aryl groups, and aryloxy groups. group, alkyl group,
It may be substituted with an acyl group, cyano group, hydroxy group, furfuryl group, etc.

R3 is a hydrogen atom, an alkyl group having 2 to 12 carbon atoms,
More preferred are aryl groups having 6 to 12 carbon atoms.

R1 is a hydrogen atom, methyl group, ethyl group, n-butyl group, n-octyl group, 2-ethylhexyl group, n-dodecyl group, n-octadecyl group, benzyl group, p-methylbenzyl group, phenethyl group, β -F22ndoxyethyl group β-(4-methoxyphenoxy)ethyl group, phenyl group, 4-methylphenyl group, and the like.

Among the substituents represented by R1 in the above formula, alkyl groups and alkoxy groups having 1 to 18 carbon atoms are preferred, and these include halogen atoms, alkoxy groups, aryl groups, aryloxy groups, alkyl groups, acyl groups, and cyano groups. , a hydroxy group, a furfuryl group, etc.

R1 is particularly preferably an alkoxy group from the viewpoint of color development.

As R1, methyl group, ethyl group, methoxy group, ethoxy group, propoxy group, isopropoxy group, n-butoxy group, n-hexyloxy group, n-octyloxy group,
2-ethylhexyloxy group, n-dodecyloxy group,
Examples include n-octadecyloxy group, benzyloxy group, p-methylbenzyloxy group, phenethyloxy group, β-phenoxyethoxy group, β-(4-methoxyphenoxy)ethoxy group, and the like.

Among the substituents represented by 12 mono- or dialkylamino groups and monoacylamino groups having 1 to 12 carbon atoms are preferred.

Preferably in ff1A. Y is selected from the groups indicated by X. n is an integer from 1 to 6, Z is an oxygen atom, a sulfur atom, -NRs -
represents. R3 is preferably selected from the groups represented by R1 in terms of cost and color development.

Next, specific examples of the color former of the present invention are shown in Table 1, 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 40% or more from the viewpoint of improving properties.

Regarding these, for example, specific examples of phthalides are U.S. Patent Reissue No. 23,024 and U.S. Patent Specification No. 3.
．． No. 491,111, No. 3,491.112, No. 3,491,116, and No. 3,509,174, and specific examples of fluorans are given in U.S. Patent Specification No. 3,624.
．． No. 107, No. 3.627.787, No. 3.64
No. 1.011, No. 3,462.828, No. 3.6
No. 81.390, No. 3.9'20.510, No. 3
．． No. 959.571, specific examples of spiropyrans are given in U.S. Patent No. 3.971,808, and pyridine and pyrazine compounds are given in U.S. Patent No. 3.775.42.
No. 4, No. 3.853゜869, No. 4,246.3
No. 18, specific examples of fluorene compounds are given in Japanese Patent Application No. 61-2
No. 40989, etc. Some examples of these include crystal violet lactone, 3.3-bis(P-dimethylaminophenyl)phthalide, and 3-(4-diethylamino-2-ethoxyphenyl)-3-(1) as triarylmethane compounds. -n-octyl-2-methylindol-3-yl)phthalide, 3-
(4-diethylamino-2-ethoxyphenyl)-3-
(1-n-octyl-2-methylindol-3-yl)-4-azaphthalide, which is a diphenylmethane compound, and 4,4-bisdimethylaminobenzhydrylbenzyl ether, N-herophenyl leuco There are auramine, N-2,4,5,-trichlorophenylleucoauramine, etc., and xanthine compounds include rhodamine-B-anilinolactam, rhodamine (p-nitroanilino)lactam, rhodamine B-(p-chloroanilino) ) lactam, 2-dibenzylamino-6-diethylaminofluorane, 2-anilino-3-methyl-6
-diethylaminofluorane, 2-anilino-3-methyl-6-sibutylaminofluorane, 2-anilino-6
-diethylaminofluorane, 2-anilino-3-methyl-6-N-cyclohexyl-N-methylaminofluorane, 2-0-chloroanilino-6-diethylaminofluorane, 2-m-chloroanilino-6-diethylaminofluoran Oran, 2-(3,4-dichloroanilino)-6
-diethylaminofluorane, 2-octylamino-6
-diethylaminofluorane, 2-dimoxylamino-
6-diethylaminofluorane, 2-m-trifluoromethylanilino-6-diethylaminofluorane, 2-butylamino-3-chloro-6-diethylaminofluorane, 2-ethoxyethylamino-3-chloro-6-diethylamino Fluoran, 2-p-chloroanilino-3-
Methyl-6-sibutylaminofluorane, 2-anilino-3-methyl-6-sioctylaminofluorane, 2-
Anilino-3-chloro-6-diethylaminofluorane, 2-diphenylamino-6-diethylaminofluorane, 2-phenyl-6-diethylaminofluorane, 2
-anilino-3-methyl-6'-N-ethyl-N-isoamylaminofluorane, 2-anilino-3-methyl-
5-chloro-6-diethylaminofluorane, 2-anilino-3-methyl-6-dinithylamino-7-methylfluorane, 2-anilino-3-methoxy-6-sibutylaminofluorane, 2-o-chloroanilino-6 -sibutylaminofluorane, 2-p-ri o o 7 = I
J Meno-ethoxy-6-N-ethyl-N-isoamylaminofluorane, 2-0-chloroanilino-6-p-
Butylanilinofluorane, 2-ani+J/-3-
Pentadecyl-6-diethylaminofluorane, 2-anilino-3-ethyl-6-sibutylaminofluorane,
2-anilino-3-methyl-4,5-dichlorofluorane, 2-〇-toluidino-3-methyl-6-diitubrobylamino-6-dimethylaminofluorane, 2-anilino-3-methyl-6- Examples include N-ethyl-Nr-methoxypropylaminofluorane, 2-anilino-3-chloro-6-N-ethyl-N-isoamylaminofluorane, and thiazine compounds include benzoylleucomethylene blue. , spiropyran compounds include 3-ethyl-spiro-dinaphthopyran, 3,3-cyclorosespiro-dinaphthopyran, 3-benzyl-spiro-dinaphthopyran, 3-methyl-naphtho-(3-methoxybenzo)spiropyran, etc. .

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. may be used in combination. Examples of these are Special Publication No. 40-9309, Special Publication No. 45-14039,
JP-A-52-140483, JP-A-48-51510
No., JP-A-57-210886, JP-A-58-870
No. 89, JP-A-59-11286, - JP-A-60-1
No. 76795, JP-A No. 61-95988, etc.

Among these, a combination of a salicylic acid derivative having 15 or more carbon atoms or a metal salt thereof and a coloring agent represented by formula (I) is preferred from the viewpoint of coloring hue, coloring property, and light resistance of a colored image. Salicylic acid derivatives are particularly preferably di-substituted, and examples of the substituent include an aralkyl group having 7 to 20 carbon atoms, an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, and a cycloalkyl group having 1 to 8 carbon atoms. Examples include an alkoxy group which may have ~8 substituents, an aryl group having 6 to 12 carbon atoms, an arylsulfonyl group, and a haloken atom.

Specific examples include 4-phenylphenol, 2゜2-bis(4-hydroxyphenyl)furopane, 2.2-bis(
3-methyl4-hydroxyphenyl)propane, 1.1
-bis(3-chloro-4-hydroxyphenyl)cyclohexane, 1.1-bis(3-10-4-hydroxyphenyl)=2-ethylbutane, 1.4-bis(4-
hydroxycumyl)benzene, 1,3-bis(4-hydroxycumyl)benzene, bis(2-methyl-4-hydroxy-5-t-nia'tylphenyl) sulfide, bis(4-hydroxyphenyl) sulfone, polyvinyl Benzyloxyphenol, 2.4.4-trihydroxybenzophenone, 2°2.4,4. -Tetrahydroxybenzophenone, dimethyl 4-hydroxyphthalate, methyl 4-hydroxybenzoate, 2.4.4
-) lyhydroxydiphenylsulfone, 1.5-bis(4-hydroxyphenyl)pentane, 1.6-bis-
p-hydroxyphenoxyhexane, tolyl 4-hydroxybenzoate, benzyl 4-hydroxybenzoate, 4
-m-phlolobenzyl hydroxybenzoate, β-phenethyl 4-hydroxybenzoate, β-phenoxybutyl 4-hydroxybenzoate, δ-phenoxybutyl 4-hydroxybenzoate, β-4-hydroxybenzoate
-Phenoxyethyl, 4-hydroxybenzoic acid-β
-pβ-p-Butoxyphenoxyisopropylserate-β-phenethyl, cinnamyl orsellate, -chlorophenoxyethyl orselate, -0-ethylphenoxyethyl orselate, phenylphenoxyethyl orselate, 2,4-dihydroxybenzoic acid -p-methylbenzyl, 2,4-dihydroxybenzoic acid-β-phenoxyethyl, 2,4-dihydroxy-6-methylbenzoic acid benzyl, 2゜4-dihydroxybenzoic acid-β-
p-Methoxyphenoxyethyl, 2,4.6-)-β-phenoxyethyl dihydroxybenzoate, phenoxybutyl orselate, 2,4-dihydroxybenzoic acid-β
-p-)Ryloxyethyl, 2.4-dihydroxybenzoic acid 1-β-0-chlorophenoxyethyl, 2.4-dihydroxybenzoic acid-β-p-methoxyphenoxybutyl, 4-hydroxy-2゜4-dimethyldiphenyl Sulfone, 1-t-butyl-4-p-hydroxyphenylsulfonyloxybenzene, 4-N-benzylsulfamoylphenol, methyl bis-(4-hydroxyphenyl)acetate, ditolylthiourea, 4,4-diacetyldiphenylthiourea , 3-phenylsalicylic acid, 5-p
-α-Methylbenzyl-α-methylbenzylsalicylic acid, 4-β-p-methoxyphenoxyethoxysalicylic acid, 4-β-phenoxyethoxysalicylic acid, 5-p-benzyl-α-methylbenzylsalicylic acid, 3-xylyl-5-( α, α-dimethylbenzyl) salicylic acid, 3゜5-bis-(α-methylbenzyl) salicylic acid, 2-hydroxy-1-α-ethylbenzyl-3-naphthoic acid,
3.5-dicyclopentadienylsalicylic acid, 3.5-
Di-t-octylsalicylic acid, 3-α-methylbenzyl-5-phenylsalicylic acid, 3-phenyl-5-α-methylbenzylsalicylic acid, 3-7enyl-5-α, α-
Dimethylbenzylsalicylic acid, 3.5-bis-(tolylethyl)salicylic acid, 5-(1,3-diphenylbutyl)salicylic acid, 5-[α-(α-methylbenzyl)phenylethyl]salicylic acid, 4-(mesitylmethyl)benzylsa' ) chill m, 4- (3-(4-mesitylmethylbenzyl)-2,4,6-)! J Methylbenzyl] Aromatic carboxylic acids such as salicylic acid or metal salts thereof, p-
Phenol resins such as phenylphenol formalin resin and p-butylphenolacetylene resin or their carboxylated products, polyvalent metal salts of these such as zinc, magnesium, aluminum, calcium, manganese, tin, and nickel, as well as rhodan zinc and molybdenum. Acid complexes, rhodan zinc imidazole complexes, picoline complexes, 2-benzylimidazole complexes, benzimidazole complexes, 2. -3-dimethyl-1-phenyl-3-pyrazolin-5-one complex, 1-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 P form, 1-phenyl-2,3-dibenzyl-3-pyrazolin-5-one complex, 1 -7enyl-2-benzyl-3-methyl-3-virazolin-5-one complex, β-diketone molybutenic acid complex, aliphatic carboxylic acids such as oxalic acid, maleic acid, sulfosuccinic acid, stearic acid, benzoic acid,
p-t-butylbenzoic acid, phthalic acid, gallic acid, nitrobenzoic acid, pentachlorobenzoic acid and their salts with polyvalent metals such as zinc, magnesium, alumina 1, calcium, and hydrogen chloride, hydrogen bromide, etc. Hydrohalic acids such as hydrogen chloride, boric acid, silicic acid, phosphoric acid, sulfuric acid, nitric acid, perchloric acid, aluminum, zinc, nickel,
Examples include inorganic acids such as halides such as tin, titanium, and boron, and inorganic color developers such as acid clay, attapulgide, bentonite, colloidal silica, tin silicate, iron stearate, cobalt naphthenate, nickel peroxide, and ammonium nitrate. .

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 field of recording materials and polymer resins, such as pigments, waxes, antistatic agents, ultraviolet absorbers, antifoaming agents, conductive agents, fluorescent dyes, etc. Additives such as surfactants are used.

For use with pressure sensitive paper, U.S. Patent No. 2,505.47
No. 0, No. 2,505.471, No. 2゜505.489
No. 2,548.366, No. 2.712.507, No. 2,730.456, No. 2,730.457,
It can take various forms as described in prior patents such as No. 3,103.404, No. 3,418,250, and No. 4,010.038. 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
There are interfacial polymerization methods described in US Pat. No. 9,264 and US Pat. No. 1.091.076, and the method described in US Pat.

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) 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.

Since the color former of the present invention has good solubility in synthetic oils such as alkylated naphthalene, alkylated diphenyl, and alkylated diphenyllucan, it has the advantage that it can be used in combination with low-solubility paraffinic oils.

In addition to the electron-donating colorless dye, addition of ultraviolet absorbers, antioxidants, etc. as additives to the microcapsules will not cause any problem or support. 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
No. 62-244,883, etc. Specifically, the electron-donating colorless dye and the electron-accepting compound are 10μ or less in the dispersion medium,
It is preferably used after being pulverized and dispersed to a particle size of 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. At that time, it is preferable to use a thermofusible substance in combination. These are used in finely dispersed form at the same time as the electron-donating colorless dye or simultaneously with the electron-accepting compound. These are added at a weight ratio of 20% or more and 300% or less, particularly preferably 40% or more and 150% or less, based on the electron-accepting compound.

Additives may be added to the thus obtained coating liquid as necessary to meet various requirements. Examples of additives include dispersing oil-absorbing substances such as inorganic pigments and polyurea fillers in the binder to prevent the recording head from becoming dirty during recording, and to improve the releasability of the head. Fatty acids, metal soaps, etc. are added to increase the coloring.Therefore, in addition to electron-donating colorless dyes and electron-accepting compounds that directly contribute to color development, thermofusible substances, pigments, waxes, antistatic agents, Additives such as ultraviolet absorbers, antifoaming agents, conductive agents, fluorescent dyes, and surfactants are coated onto the support to form a recording material.

Furthermore, a protective layer may be provided on the surface of the heat-sensitive recording layer, if necessary. The protective layer may be formed by laminating two or more layers, if necessary. Further, a coating liquid similar to 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, inbutylene-maleic anhydride copolymer, polyacrylic acid, polyacrylic acid amide, methylol-modified polyacrylamide, starch derivatives, casein, gelatin, etc. . 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 phenethyl biphenyl, 2-benzyloxynaphthalene, 4-benzylbiphenyl, di-m-
Tolyloxyethane, β-phenoxyethoxyanisole, 1-7 enoxy 2-p-ethylphenoxyethane, bis-[β-(p-methoxyphenoxy)ethoxycomethane, 1-(2-methoxyphenoxy)-2-(
4-ethyloxyphenoxy)ethane, 1,2-diphenoxyethane, 1,4-diphenoxybutane, bis-[
β-(p-methoxyphenoxy)ethyl ether, 1
-phenoxy-2-p-chlorophenoxyethane, 1-
(4-Methylphenoxy)-2-(4-fluorophenoxy)ethane, 1-phenoxy-2-p-methoxyphenylthioethane, 1,2-bis(p-methoxyphenylthio)ethane, 1-tolyloxy-2- Examples include ether compounds such as p-methoxyphenylthioethane, stearamide, methylene bisstearamide, stearanilide, behenic acid amide, stearic acid aniside, and stearyl urea.

Pigments include kaolin, calcined kaolin, talc, waxite, diatomaceous earth, calcium carbonate, aluminum hydroxide,
Magnesium hydroxide, zinc oxide, lithopone, amorphous silica, colloidal silica, calcined stone wax, silica, magnesium carbonate, titanium oxide, alumina, barium carbonate, barium sulfate, mica, microballoon, urea-formalin filler, polyester particles, Cellulose filler or the like is 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, 1.1.3-tris(2-ethyl-4-
Hydroxy-5-t-butylphenyl)butane, 1,1
．． 3-tris(3,5-di-t-butyl-4-hydroxyphenyl)butane, 1.1.3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)propane, 4.4- Butylidenebis(6-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-)lis(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 given.

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-t-butylphenol, 0-benzotriazolyl-2,4-di-t -Octylphenol etc.

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, and imbutylene-maleic anhydride copolymer. It will be done.

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, inbutylene-maleic anhydride copolymer hydrolyzate, polyacrylamide derivatives, polyvinylpyrrolidone, polystyrene sodium sulfonate, and sodium alginate, and styrene-
Water-insoluble pofmers such as butadiene rubber latex, acrylonitrile-butadiene rubber latex, methyl acrylate-butadiene rubber latex, and vinyl acetate 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, for example, by the method described in JP-A-49-11344 and JP-A-50-48930. Generally, a coating liquid in which a conductive substance, an electron-donating colorless dye, and an electron-accepting compound are 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, and then a conductive layer is formed on the support. 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. 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 bromide, silver bromide, silver behenate, Michler's ketone, benzoin derivatives, benzophenone derivatives, etc. and crosslinking agents such as polyallyl compounds, poly(meth)acrylates, poly(meth)acrylamides, etc. 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 produced by a known method.

For example, it can be produced by reacting a compound of formula (II) with a compound of formula (In), or alternatively, by reacting a compound of formula (IV) with a compound of formula (V). In the above formula, R+ SR1, R3, R4, XN m and A have 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 4O-130t.
It will last for ~10 hours.

Compounds of formula (II) and (IV) are generally obtained by reacting an anhydride of formula (VI) with a compound of formula (V) or (I[).

In this case, the reaction is preferably carried out in an organic solvent such as methylene chloride, ethylene chloride, toluene, chlorobenzene or acetic acid in the presence of a Lewis acid such as aluminum chloride or zinc chloride. The reaction temperature is set at -10°C to 100°C, preferably 0°C to 70°C.

Synthesis Example 1 3-(4-diethylamino-2-ethoxyphenyl)-
3-(1-n-octylindol-3-yl)-4-
Weigh 0.2M of abphthalide anhydrous quinoline ff, 0.1M of 1-n-octylindole, 2001n1 of ethylene chloride, and stir to bring the internal temperature to 3°C.
0.6M of anhydrous aluminum chloride was gradually added and stirred at 20°C for 3 hours. The reaction mixture is poured into diluted hydrochloric acid water to decompose unreacted aluminum chloride, and then washed with water several times, and the organic layer is concentrated.

The concentrated residue contains 0 N,N-diethyl-m-phenetidine.
．． IM, acetic anhydride 20mj! Add and stir at 60℃ for 2 hours. The reaction mixture is poured into water and made alkaline with aqueous sodium hydroxide solution. This reaction mixture is subjected to column chromatography using a mixed solvent of n-hexane-acetate to obtain the desired product as white crystals with a melting point of 111-2°C.

Synthesis example 2 3- (4-diethylamino-2-ethoxyphenyl)
-3-(1-n-octylindol-3-yl)-7
-Azaphthalide anhydrous quinoline 1820. Weigh 12M, 0.1M of 1-n-octylindole, and 200% of ethylene chloride into a flask equipped with a stirrer, and stir until the internal temperature is 3.
Cool to ℃, add 0.36M anhydrous zinc chloride gradually, and stir at 40℃ for 5 hours.

The reaction mixture is poured into diluted hydrochloric acid water, washed several times with water, and the organic layer is concentrated.

The concentrated residue contains 0 N,N-diethyl-m-7enetidine.
．． IM, 20ml of acetic anhydride! Add and stir at 60℃ for 2 hours. The reaction mixture is poured into water and made alkaline with aqueous sodium hydroxide solution. This reaction mixture was subjected to column chromatography using a mixed solvent of n-hexanes and acetate to obtain the desired product as white crystals with a melting point of 109-10°C.

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

(1) Preparation of capsule sheet containing electron-donating colorless dye 5 parts of a partial sodium salt of polyvinylbenzenesulfonic acid (manufactured by National Starch Co., Ltd., VER3A, TL500) is dissolved in 95 parts of hot water and then cooled. This is hydroxylated)
+Jum aqueous solution was added to adjust the pH to 4.0. Diisopropyl naphtha, a and zinc 2-ethylhexanoate (8:2
Weight mixing '1) 11 > 100 R 5% aqueous solution of partial sodium salt of the polyvinylbenzenesulfonic acid 1
00 parts to obtain an emulsion having a particle size of 4.0 μm in diameter. Separately, 6 parts of melamine, 11 parts of a 37% by weight formaldehyde aqueous solution, and 30 parts of water were heated and stirred at 60° C., and after 30 minutes, a transparent aqueous solution of a melamine-formaldehyde prepolymer was obtained.

This aqueous solution was mixed with the above emulsion. While stirring, the pH was adjusted to 6.0 with a 2M phosphoric acid solution, the temperature of the solution was raised to 65°C, and stirring was continued for 6 hours. The capsule liquid was cooled to room temperature and adjusted to pH 9.0 with an aqueous solution of IJ (hydroxide).

- To this dispersion, 200 parts of a 10% by weight polyvinyl alcohol aqueous solution and 50 parts of starch particles were added, and water was added to prepare a solution of a microcapsule dispersion with a solid content concentration of 20%.

This coating solution was applied to a 50 g/m'2 base paper using an air knife coater so that a solid weight of 5 g/m'2 was coated, and dried to obtain a capsule sheet containing an electron-donating colorless dye.

(2) Preparation of electron-accepting compound sheet 3.5-bis-α-methylbenzylsalicylic acid zinc salt 1
0 parts was added to 20 parts of 1-inpropylphenyl-2-phenylethane and dissolved. This was mixed with 50 parts of a 2% polyvinyl alcohol aqueous solution and 0.1 part of a 10% dodecylbenzenesulfonic acid trienolamine salt aqueous solution and emulsified so that the average particle size was 3 μm.

Next, a dispersion consisting of 80 parts of calcium carbonate, 20 parts of zinc oxide, 1 part of sodium hexametaphosphate, and 200 parts of water was mixed with the above emulsion and added as a binder to 100 parts of a 10% PVA aqueous solution and carboxylic acid. Modified SBR
10 parts of latex (as solid content) was added and water was added so that the solid content concentration was 20% to obtain a coating liquid (A).

Next, a dispersion consisting of 10 parts of the color developer, 20 parts of Jilton clay, 60 parts of calcium carbonate, 20 parts of zinc oxide, 1 part of sodium hexametaphosphate, and 200 parts of water was ground to an average particle size of 3 μm using a sand grinder. It was dispersed as follows.

Add 16 parts of 10% PVA aqueous solution and 10% PVA to this dispersion.
100 parts of an aqueous solution and 10 parts of carboxy-modified SBR latex (as solid content) were added, and water was added so that the solid content concentration was 20% to obtain a coating liquid (B).

Coating liquid (A) and coating liquid (B) were mixed at a ratio of 1:1 in terms of color developer, and coated on a base paper of 50 g/m' with an air knife coater so that a solid content of 5.0 g/m2 was applied. The mixture was coated and dried to obtain a developer sheet.

The surface of the microcapsule sheet containing an electron-donating colorless dye is
When the electron-accepting compound sheets were stacked and a load of 600 kg/m2 was applied, each sheet quickly developed a blue color. The light fastness of the resulting image was excellent.

(Examples 1 to 4) The coloring agent used is as follows.

Example 1 Compound of Specific Example (1) Example 2 Compound of Specific Example (13) Example 3 Mixture of 7/3 (weight ratio) of the compound of Specific Example (6) and crystal violet lactone Example 4 Specific Example (1) ) and 3-(4-diethylamino-2
-ethoxyphenyl)-3-(1-n-octyl-2-
3 of methylindol-3-yl)-4-azaphthalide
72 (weight ratio) Mixture Example 5 20 g of the compound of specific example (8) 1 20 g of zinc 4-β-p-methoxyphenoxysalicylate, which is an electron-accepting compound
g, 20 g of stearic acid amide, a thermofusible substance, 1
00g of 5% polyvinyl alcohol (Kuraray PVA10
5) Dispersion was carried out with an aqueous solution in a Pall mill overnight to give a volume average particle size of 3 μm. On the other hand, calcined kaolin (Anis
160 g of a 0.5% solution of sodium hexametaphosphate was dispersed using a homogenizer.

Each of the dispersions dispersed as described above was mixed in a ratio of 5 g of an electron-donating colorless dye dispersion, 10 g of an electron-accepting compound dispersion, 5 g of a stearamide dispersion, and 22 g of a calcined kaolin dispersion. emulsion 4
g and 5 g of a 2% aqueous solution of sodium (2-Z-tylhexyl)sulfosuccinate were added to obtain a coating liquid. Apply this coating liquid to a dry coating amount of 6 g on high-quality paper with a basis weight of 50 g/m2.
/m2 using a wire bar, and calendering was performed to obtain coated paper.

The coated paper is Fujitsu Limited High Speed Fax 'JFF-20.
When color was developed using 00, a blue image was obtained. This image had high density and excellent light resistance and heat resistance.

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 compound represented by the following general formula (I) is used as the electron-donating colorless dye. ▲Contains mathematical formulas, chemical formulas, tables, etc.▼(I) In the above formula, R_1 and R_2 are alkyl groups, R_3 is a hydrogen atom, an alkyl group, or an aryl group, and R_4 is an alkyl group or an alkoxy group. , X represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a nitro group or a substituted amino group, m represents an integer from 1 to 4, and Ring A represents an aromatic ring having at least one nitrogen atom.