JPH0465292A - Thermal recording material - Google Patents

Abstract

PURPOSE:To obtain printing quality enhanced in sensitivity and improved in raw preservability and the stability of a developed color image by adding a salicylic acid derivative having an aryloxyalkyloxy group as a substituent or a metal salt thereof and a specific compound to a thermal color forming layer. CONSTITUTION:In a thermal recording material wherein a thermal color forming layer containing an electron donating leuco dye and an electron acceptive compound is provided on a support, a salicylic acid derivative having an aryloxyalkyloxy group or a metal salt thereof and a compound represented by formula I (wherein R<1>, R<2> and R<3> are a lower alkyl group and l is an integer of 1-4) are added to the thermal color forming layer to obtain the recording material having high sensitivity, generating no fog color development or the erasure of a developed color part and having extremely excellent properties. The compound represented by the formula I must occupy 50wt.% or more of the electron donating leuco dye and can be used together with other electron donating leuco dye.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a heat-sensitive recording material, and more particularly to an electron-donating colorless dye and an electron-donating colorless dye that have improved color development, shelf life, and stability of colored images. The present invention relates to a heat-sensitive recording material in which a coloring layer containing an electron-accepting compound is provided on a support.

(Prior Art) Recording materials using electron-donating colorless dyes and electron-accepting compounds are already well known as pressure-sensitive paper, thermal paper, light-sensitive pressure-sensitive paper, electrically conductive thermal recording paper, thermal transfer paper, and the like. For example, British Patent No. 2.140.449, U.S. Patent No. 4,48
No. 0.052, No. 4.436,920, Special Publication No. 1983
-23992, JP-A-57-179836, JP-A No. 60
-123556, 60-123557, etc. for details. In particular, heat-sensitive recording materials are detailed in Japanese Patent Publications No. 43-4160 and Japanese Patent Publication No. 45-14039.

These thermal recording systems are being applied to a wide variety of fields such as facsimiles, printers, and labels, and the needs are expanding. However, heat-sensitive recording materials have the disadvantage of fogging caused by solvents, etc., and the disadvantage that the color-forming material causes discoloration due to oils, fats, chemicals, etc., so labels, etc.
In the fields of slips, word processor paper, plotter paper, etc., the value of products has been significantly diminished. The present inventors investigated the oil solubility, water solubility, 1 distribution coefficient, ρKa
We have pursued the development of good materials for recording materials and recording materials by focusing on the polarity of substituents and the position of substituents. However, by imparting these resistances, a problem has arisen in that the sensitivity is significantly reduced.

(Objective of the Invention) An object of the present invention is to provide a heat-sensitive recording material which is highly sensitive, has good printing quality, and has good shelf life and stability of colored images.

(Structure of the Invention) An object of the present invention is to provide a heat-sensitive recording material in which a heat-sensitive coloring layer containing an electron-donating colorless dye and an electron-accepting compound is provided on a support. This was achieved by a heat-sensitive recording material characterized by containing a salicylic acid derivative having a bovine group as a substituent or a metal salt thereof, and also containing a compound represented by the following general formula (1).

(R', R2, R3 represent a lower furkyl group, and ! is 1
Represents an integer of ~4. ) Among the salicylic acid derivatives according to the present invention, the following general formula (1
Those represented by 1) are preferred.

In the above formula, Ar represents an aryl group, and x represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom.

M represents an n-valent metal atom, and m and nIi represent integers.

Note that the furkyl group represents a saturated or unsaturated furkyl group or cycloalkyl group, which has a substituent such as an aryl group, a flukoxy group, an aryloxy group, a halogen atom, an acylamino group, an aminocarbonyl group, or a cyano group. Also, the 7-aryl group represents a phenyl group, a naphthyl group, or a heteroaromatic group, and these are furkyl groups.

Flukoxy group, 7-aryloxy group, halogen atom.

Nido O group, cyano group, substituted carbamoyl group, substituted sulfamoyl group, substituted 7-mino group, substituted oxycarbonyl group,
It may have a substituent such as a substituted oxysulfonyl group, thioalkoxy group, arylsulfonyl group, or phenyl group.

Among the substituents represented by Ar in the above formula, the number of carbon atoms is 6 to 2
Of the substituents represented by x, a hydrogen atom, a furkyl group having 1 to 9 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms are preferred.

Chlorine atoms and fluorine atoms are preferred, and among the metal atoms represented by M, zinc, aluminum, magnesium, and calcium are preferred.

Among the substituents of the aryl group represented by Ar, a flukoxy group having 1 to 12 carbon atoms, a furkyl group having 1 to 20 carbon atoms, a 7-ralkyl group having 7 to 16 carbon atoms, a halogen atom, a phenyl group, or A flukoxycarbonyl group is preferred.

Preferred examples of the 7-aryl group represented by Ar include phenyl group, tolyl group, ethylphenyl group, propylphenyl group, butylphenyl group, cyclohexylphenyl group,
octylphenyl group, nonylphenyl group, dodecylphenyl group, benzylphenyl group, phenethylphenyl group,
Cumylphenyl group, xylyl group, diphenethylphenyl group, methoxyphenyl group, ethoxyphenyl group, benzyloxyphenyl group, octyloxyphenyl group, dodecyloxyphenyl group, ri00phenyl group, fluorophenyl group, phenylphenyl group, hexyloxycarbonyl group Phenyl group, benzyloxycarbonylphenyl group,
Examples include dodecyloxypolonylphenyl group, naphthyl group, methylnaphthyl group, and chloronaphthyl group.

The substitution position of the aryloxyalkyloxy group is Coo
Particularly preferred is the para position relative to the (H or Ml/-) group.

The salicylic acid derivative according to the present invention is preferably a compound having a total number of carbon atoms of 12 or more from the viewpoint of water insolubility, particularly 14
The above is preferable.

The recording material using the salicylic acid derivative according to the present invention has sufficient color density, and the developed pigment is extremely stable, and hardly changes color even after long-term light irradiation, heating, and humidification. This is particularly advantageous from the viewpoint of preservation. In addition, when used in heat-sensitive recording materials, it is ideal as an electron-accepting compound for recording materials because it does not have the disadvantages of color development in uncolored areas due to solvents, etc., or discoloration of color-forming bodies due to oils, fats, chemicals, etc. It has a performance close to that of

Next, specific examples of the electron-accepting compound according to the present invention will be shown.

4-β-phenoxyethoxysalicylic acid, 4-(4-phenoxybutoxy)salicylic acid, 4-(6-funinoxyhexyloxy)salicylic acid.

4-(5-phenoxy7myloxy)salicylic acid.

4-(8-phenoxyoctyloxy)salicylic acid, 4
-(10-phenoxydecyloxy)salicylic acid, 4-
β-p-tolyloxyethoxysalicylic acid, 4-β-m
-) Ryloxyethoxysalicylic acid, 4-β-ρ-ethylphenoxyethoxysalicylic acid, 4-β-p-isopropylphenoxyethoxysalicylic acid, 4-β-ρ-t
-butylphenoxyethoxysalicylic acid, 4-β-p-
Cyclohexylphenoxyethoxysalicylic acid, 4-β
-pt-octylphenoxyethoxysalicylic acid, 4
-β-p-nonylphenoxyethoxysalicylic acid, 4-
β-p-dodecylphenoxyethoxysalicylic acid, 4-
β-ρ-Benzylphenoxyethoxysalicylic acid, 4-
(2-p-α-phenethylphenoxyethoxy) salicylic acid, 4-β-0-methoxyphenoxyethoxysalicylic acid.

4-β-p-cumyloxyethoxysalicylic acid.

4-β-(2,4-dimethylphenoxy)ethoxysalicylic acid, 4-β-(3,4-dimethylphenoxy)ethoxysalicylic acid, 4-β-(3,5-dimethylphenoxy)ethoxysalicylic acid, 4-β-( 2,4-bis-α
-Phenethylphenoxy)ethoxysalicylic acid, 4-β
-p-methoxyphenoxyethoxysalicylic acid, 4-β
-p-ethoxyphenoxyethoxysalicylic acid, 4-β
-p-benzyloxyphenoxyethoxysalicylic acid,
4-β-p-dodecyloxyphenoxyethoxysalicylic acid, 4-β-p-reoxyphenoxyethoxysalicylic acid, 4-β-p-phenylphenoxyethoxysalicylic acid, 4-β-p-cyclohexylphenoxyethoxysalicylic acid, 4-β-p-benzyloxycarbonylphenoxyethoxysalicylic acid, 4-β-p-dodecyloxycarbonylphenoxyethoxysalicylic acid, 4-β-
naphthyl(2)oxyethoxysalicylic acid, 5-β-p
-Ethylphenoxyethoxysalicylic acid.

4-β-phenoxyethoxy-6-methylsalicylic acid,
4-β-phenoxyethoxy-6-chloroO salicylic acid,
4-β-phenoxybutyloxysalicylic acid, 4
-ω-p-methoxyphenoxy-3-oxa-n-pentyloxysalicylic acid.

4-ω-p-methoxyphenoxy-3-oxa-n-pentyloxysalicylic acid and their metal salts,
These may be used alone or in combination.

The metal salt according to the present invention is a divalent or trivalent metal.

For example, salts with metals selected from zinc, magnesium, barium, calcium, aluminum, tin, titanium, nickel, cobalt, manganese, iron, etc. are preferred, and zinc compounds are particularly preferred.

According to the invention. What is the dispersed particle size of a salicylic acid derivative or its metal salt after it is atomized using a sand mill or the like?

In order to obtain color development sensitivity, it is preferably 3 μ or less, preferably 2 μ.
It is preferable to atomize the particles to below.

In addition, the salicylic acid derivatives according to the present invention include well-known salicylic acid derivatives other than the present invention, metal salts of aromatic carboxylic acids, phenol derivatives, phenolic resins, novolac resins, metal-treated novolac resins, metal complexes, acid clay, An electron-accepting compound such as bentonite may be used in combination.

Examples of these are Special Publication No. 9309 of 1972 and Special Publication No. 1 of 1973.
No. 4039, JP-A-52-140483, JP-A-48
-51510, JP-A-57-210888, JP-A-58-87089, JP-A-59-11286, JP-A-60-176795, JP-A-61-95988, etc.

Some examples of these include 4-tert-butylphenol, 4-phenylphenol, and 4-hydroxydiphenoxide-α-naphthol.

β-naphthol, hexyl-4-hydroxybenzony), 2,2'-dihydroxybiphenyl.

2.2-bis(4-hydroxyphenyl)propane (bisphenol A), 4.4'-isopropylidenebis(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-tert-octylphenol.

4+ 4'-5ee-butylidene diphenol, 4-
ρ-methylphenylphenol, 4.4'-isopentylidenephenol, 4.4'-methylcyclohexylidenediphenol, bis(3-7ly-4-hydroxyphenyl)sulfone, 4-hydroxyphenyl-3
゛4゛ Dimethylphenylsulfone, 4-(4-inbuOboxyphenylsulfonyl)phenol, 4.4'
-dihydroxydiphenyl sulfide, 1.4-bis-(4'-hydroxycumyl)benzene, 1.3-bis-(4'-hydroxycumyl)benzene, 4.4'-
Thiobis(13-tert-butyl-3-methylphenol)r4.4'-dihydroxydiphenylsulfone, hydroquinone monobenzyl ether, 4-hydroxybenzophenone, 2,4-dihydrobaf dibenzophenone, polyvinylbenzyloxycarponylphenol,
2.4.4'-) Lihydrooxybenzophenone, 2.
2', 4゜4'-tetrahydroxybenzophenone,
4-human O-oxyphthalic acid, methyl dimethyl-4-hydroxybenzoate, 2,4,4'-trihydroxydiphenylsulfone, 1,5-bis-p-hydroxyphenylpentane, 1,6-bis-p-hydroxyphenoxy Hexane, tolyl 4-hydroxybenzoate, 4-hydroxybenzoic acid α-phenylbenzyl ester, phenylpropyl 4-hydroxybenzoate, phenethyl 4-hydroxybenzoate, 4-hydroxybenzoic acid-ρ-chloroO
Benzyl, 4-human O-oxybenzoic acid-p-methoxybenzyl, 4-hydroxybenzoic acid benzyl ester, 4-
Human O-oxybenzoic acid-m-chlorobenzyl ester, 4
-Human 0xybenzoic acid-β-phenethyl ester, 4-
Hydroxy-2', 4'dimethyldiphenylsulfon β-phenethylorselinate, cinnamyl orselinate, orselic acid-〇-chloro-O phenoxyethyl ester, 0-ethylphenoxynityl orselinate.

0-Phenylphenoxyethyl orcelinate.

m-Phenylphenoxyethyl orcelinate.

2.4-dihydroxybenzoic acid-β-3'-t-butyl-4'-hydroxyphenoxyethyl ester, 1-
t-Butyl-4-p-hydroxyphenylsulfonyloxybenzene, 4-N-benzylsulf7moylphenol, 2,4-dihydroxybenzoic acid-β-phenoxyethyl ester, 2゜4-dihydroxy-6-methylbenzoic acid benzyl ester , methyl bis-4-hydroxyphenylacetate, ditolylthiourea, 4.4'-diacetyldiphenylthiourea, 3-phenylsalicylic acid, 3-SchiffOhexylsalicylic acid, 3.5-diter
t-Butylsalicylic acid, 3-methyl-5-benzylsalicylic acid, 2-phenyl-5-(α.

α-dimethylbenzyl)salicylic acid, 3,5-di(α
-methylbenzyl)salicylic acid + 5-t-octylsalicylic acid, 3,5-di-t-butylsalicylic acid, 3-chloro-5-cumylsalicylic acid.

3-Methyl-5-t-octylsalicylic acid, 3-methyl-5-α-methylbenzylsalicylic acid, 3-methyl-5
-cumylsalicylic acid, 3,5-di-7milsalicylic acid, 3-phenyl-5-benzylsalicylic acid, 3-phenyl-5-t-octylsalicylic acid, 3-phenyl-5
-α-Methylbenzylsalicylic acid, 3.5-di-octylsalicylic acid, 3.5-bis(α-methylbenzyl)salicylic acid, 3,5-dicumylsalicylic acid, 4-methyl-5-(α-methylbenzyl) salicylic acid.

4-Methyl-5-cumylsalicylic acid, 3-(α-methylbenzyl)-6-methylsalicylic acid, 3-(α-methylbenzyl)-6-phenylsalicylic acid.

3-triphenylmethylsalicylic acid, 3-diphenylmethylsalicylic acid, 4-n-dodecylsalicylic acid, 4-t
-dodecylsalicylic acid, 4-n-dodecylsalicylic acid,
4-n-pentadecylsalicylic acid, 4-n-heptadecylsalicylic acid, 5-(1,3-diphenylbutyl)-salicylic acid, 5-n-octadecylsalicylic acid, 4-pentadecylsalicylic acid, 3.5-bis(α- methylbenzyl) salicylic acid, 3I 5-bis-t-octylsalicylic acid, 5-octadecyl salicylic acid, 5-α-(p-α
-methylbenzylphenyl)ethylsalicylic acid, 3-α
-Methylbenzyl-5-t-octylsalicylic acid, 5-
Tetradecyl salicylic acid.

4-hexyloxysalicylic acid, 4-cyclohexyloxysalicylic acid, 4-octyloxysalicylic acid, 4-
Decyloxysalicylic acid, 4-dodecyloxysalicylic acid, 4-tetradecyloxysalicylic acid, 4-pentadecyloxysalicylic acid.

4-hexadecyloxysalicylic acid, 4-octadecyloxysalicylic acid, 4-icosyloxysalicylic acid, 4
-Tri7contyloxysalicylic acid.

4-Oleyloxysalicylic acid, 4-β-phenethyloxysalicylic acid, 4-β-dodecyloxyethoxysalicylic acid, 4-(12-Rhododecyl)oxysalicylic acid, 4-β-N-stear0ylaminoethoxysalicylic acid, 4- β-N-mylinutoylaminoethoxysalicylic acid, 4-β-perfluorohexylethoxysalicylic acid, 4-dodecyloxy-5-chlorosalicylic acid, 4-dodecyloxy-5-methylsalicylic acid, 4-dodecyloxy-6-methyl Salicylic acid, 4-dodecyloxy-6
-Phenylsalicylic acid, 4-methoxy-6-dozosyloxysalicylic acid, 6-octazosyloxysalicylic acid+
4-pt-octylphenyloxysalicylic acid, 4-
p-dodecyloxyphenyloxysalicylic acid, 4-p
-chlorophenoxy-6-butylsalicylic acid, 4-p-
Phenylphenoxysalicylic acid + 4-p-N-myristoylcarbamoylphenyloxysalicylic acid.

4-benzyloxy-6-dodecyloxysalicylic acid,
Examples include 5-dodecylsulfonylsalicylic acid, 5-dodecylsulfosalicylic acid, and 3-methyl-5-dodecylsulfosalicylic acid.

The electron-accepting compound is an electron-donating colorless dye of 50 to 80
It is preferable to use 0% by weight, more preferably 1% by weight.
00 to 500% by weight. The electron-accepting compound described above is preferably mixed in a proportion of 2000 to 10% by weight with respect to the salicylic acid derivative which is the electron-accepting compound according to the present invention. Further, two or more of the above electron-accepting compounds may be used in combination.

Specific examples of the compound represented by compound (1) according to the present invention include 2-7nilino-3-methyl-6-N-methyl-N-γ-nitoxypropylaminofluorane, 2-7
Nilino 3-methyl-6-N-ethyl-N-γ-methoxypropylaminofluorane, 2-7 Nilino 3-methyl-6-N-ethyl-N-γ-ethoxib Opyr 7 Minofluorane, 2-7 Nilino 3 -Methyl-6-N-ethyl-N-β-ethoxyethyl 7minofluorane.

2-7 Nilino 3-methyl-6-N-ethyl-N-γ-
Examples include propoxypropyl 7-minofluorane.

In the present invention, it is necessary that the compound (1) accounts for 50% by weight or more of the electron-donating colorless dye. Under the above-mentioned conditions, it can be used in combination with other electron-donating colorless dyes. Examples of electron-donating colorless dyes that can be used in combination are shown below.

Examples of electron-donating colorless dyes include triphenylmethane phthalide compounds, fluoran compounds, phenothiazine compounds, indolyl phthalide compounds, leucoolamine compounds, O-damine lactam compounds, and triphenylmethane compounds. , triazene compounds, spiropyran compounds, and fluorene compounds. Specific examples of phthalides can be found in U.S. Reissue Patent Specification Letter 2
3゜024, U.S. Patent Specification No. 3.491.111, U.S. Patent No. 3.491,112, U.S. Patent No. 3.491゜116
No. 3,509,174, and specific examples of fluorans are given in U.S. Patent Specification No. 3.624゜107, Inter 3.
．． No. 827.787, No. 3641.011, No. 3,462.828, No. 3.681.390, No. 3.920,510, No. 3,959.5171, Specific examples of subirodipyrans are listed in U.S. Patent Specification 3.9.
71°808; pyridine and pyrazine compounds are disclosed in U.S. Patent No. 3.775,424; U.S. Patent No. 3.8;
Specific examples of fluorene compounds are described in No. 53.869, No. 4,246.318, and Japanese Patent Application No. 61-240989.

Among these, black-colored 2-7 lyl 7 minnow 3-H, halogen-, alkyl- or alkoxy-6-substituted 7-minofluorane are particularly effective.

Specific examples include 2-7nilino-3-methyl-6-diethyl-7minofluorane and 2-7nilino-3-methyl-6-N-cyclohexyl-N-methylaminofluorane.

2-ρ-riOroanilino-3-methyl-6-diptyl 7
Minofluorane, 2-7 dilino-3-methyl-6-cyoctylaminofluorane, 2-7 dilino-3-rioo-
6-diethyl 7-minofluorane, 2-7 nilino-3-methyl-6-N-ethyl-N-isoamylaminofluorane, 2-7 nilino-3-methyl-6-N-ethyl-N-
Dodecyl 7-minofluorane, 2-7nilino-3-methoxy-6-dipyl-7minofluorane, 2-0-chloroanilino-6-sibutylaminofluorane, 2-p-chloro07nilino-3-ethyl-8-N-ethyl-N -iso7
Mil 7 Minofluorane, 2-〇-Clo 07 Nilino 6-
ρ-Butyl 7nilinofluorane, 2-7nilino 3-pentadecyl-8-diethyl 7minofluorane, 2-7nilino 3-ethyl-6-cyptyl 7minofluorane +2
−.

-Toluidino-3-methyl-6-dibutyl-7minofluorane, 2-7nilino-3-methyl-6-N-butyl-N-ethyl7minofluorane, 2-7nilino-3-methyl-6-N-ethyl-N -Tetrahydrofurfuryl 7minofluorane.

Examples include 2-7-nily/-3-chloro-6-N-ethyl-N-yne 7-mylaminofluorane.

Examples of the sensitizer of the present invention include JP-A-58-57989
No., JP-A-58-87094, JP-A-63-3937
Examples include compounds disclosed in No. 5 and the like. Representative examples thereof include aromatic ethers (particularly benzyl ethers and di(substituted phenoxy)furkyls), esters and/or aliphatic 7-amides, ureidos, and aromatic 7-amides or ureidos.

Next, a typical method for producing a heat-sensitive coloring layer of the present invention will be described.

The electron-donating colorless dye, the electron-accepting compound, and the sensitizer are dispersed to a size of several microns or less together with an aqueous solution of a water-soluble polymer such as polyvinyl alcohol using a ball mill, sand mill, or the like. The sensitizer is added to either the electron-donating colorless dye or the electron-accepting compound, or both, and is dispersed simultaneously, or in some cases, a eutectic product is prepared in advance with the electron-donating colorless dye or the electron-accepting compound. , may be dispersed.

These dispersions are mixed after dispersion, and pigments and
Add surfactant, binder, metal soap, wax, antioxidant, ultraviolet absorber, etc. to make a heat-sensitive coating liquid.

The obtained heat-sensitive coating liquid is coated and dried on high-quality paper, high-quality paper with an undercoat layer, synthetic paper, plastic film, etc., and then smoothed by calendering to obtain the desired heat-sensitive recording material. In this case, it is particularly preferable to use a support having a smoothness defined by JIS-8319 of 500 seconds or more, particularly 800 seconds or more from the viewpoint of dot reproducibility.

To obtain a support with a smoothness of 500 seconds or more, ■ Use a material with high smoothness such as synthetic paper or plastic film ■ Provide an undercoat layer containing pigment as the main component on the support ■ Super calender There are methods such as increasing the smoothness of the support by using .

The binder is preferably a compound that dissolves 5% by weight or more in water at 25°C, and specifically, polyvinyl alcohol (including modified polyvinyl alcohols such as carboxy-modified, itaconic acid-modified, maleic acid-modified, and silica-modified polyvinyl alcohols). , methylcellulose, carboxymethylcellulose, starches (including modified starches), gelatin, gum arabic, casein, styrene-maleic anhydride copolymer hydrolyzate, polyacrylamide, saponified vinyl acetate-polyacrylic acid copolymer, etc. can be given. These binders are used not only for dispersion but also for the purpose of improving coating film strength. A synthetic polymer latex binder such as acid methyl butadiene copolymer or polyvinylidene chloride may also be used.

Further, a crosslinking agent suitable for the binder may be added depending on the type of the binder, if necessary.

Pigments include calcium carbonate, barium sulfate, lithopone, octenite, kaolin, silica, amorphous silica, and the like.

As the metal soap, higher fatty acid metal salts are used, such as zinc stearate, calcium stearate, aluminum stearate, and the like.

Furthermore, surfactants, antistatic agents, ultraviolet absorbers, antifoaming agents, conductive agents, fluorescent dyes, coloring dyes, etc. may be added as necessary.

The coated heat-sensitive recording material is dried and subjected to a process such as a calender before being used.

Further, a protective layer may be provided on the heat-sensitive coloring layer if necessary. As the protective layer, any one known as a protective layer for heat-sensitive recording materials can be used.

Furthermore, if necessary, a back coat layer may be provided on the opposite side of the support of the heat-sensitive recording material from the heat-sensitive coloring layer. As the back coat layer, any material known as a back coat layer for heat-sensitive recording materials can be used.

EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is not limited only to the Examples below.

(Example-1) 2-7nilino-3-methyl-6-N-ethyl-N-γ-ethoxypropylaminofluorane as an electron-donating colorless dye, 4-β-ρ-methoxyphenoxy as an electron-accepting compound Zinc ethoxysalicylate β as zinc sensitizer
- Naphthylbenzyl ether, 5% polyvinylflucol (Clary PVA-105) of 209 and 1009, respectively
Disperse with an aqueous solution in a ball mill overnight to reduce the average particle size to 1.
．． Each dispersion was obtained by applying a 5 μm breath. Further, calcium carbonate 809 was dispersed with a 0.5% sodium hexametaphosphate solution 1609 using a homogenizer to obtain a pigment dispersion.

The dispersions prepared above were mixed with 59 parts of an electron-donating colorless dye dispersion, 109 parts of an electron-accepting compound dispersion, 109 parts of a β-naphthylbenzyl ether dispersion, and 59 parts of a calcium carbonate dispersion, and then A heat-sensitive coating liquid was obtained by adding 21% zinc stearate emulsion 39. This heat-sensitive coloring layer coating solution was applied onto high-quality paper with a basis weight of 509/m2 using a wire bar so that the dry weight of the coating layer was 5+/rr! It was coated so as to give a heat-sensitive recording paper and dried at 50° C. for 1 minute.

(Example-2) Instead of using 2-7nilino-3-methyl-6-N-ethyl-N-γ-ethoxypropyl 7minofluorane in Example-1, 2-7nilino-3-methyl-6-N -Methyl-N-[gamma]-Ethoxybuvir 7 A thermosensitive recording paper was obtained in the same manner except that a thermosensitive coating liquid was prepared using minofluorane.

(Comparative Example-1) Instead of using 2-7nilino-3-methyl-6-N-ethyl-N-γ-ethoxypropyl 7minofluorane in Example-1, %2-7nilino-3-methyl-6-N −
A thermal recording paper was obtained in the same manner except that methyl-N-cyclohexylaminofluorane was used to prepare the thermal coating liquid.

(Comparative Example-2) Instead of using 2-7nilino-3-methyl-6-N-ethyl-N-γ-ethoxypropyl 7minofluorane in Example-1, 2-7nilino-3-chloro-6-dinityl was used. A heat-sensitive recording paper was obtained in the same manner except that a heat-sensitive coating liquid was prepared using 7-minofluorane.

(Comparative Example-3) A thermal recording paper was prepared in the same manner as in Example-1 except that bisphenol A was used instead of zinc 4-β-p-methoxyphenoxyethoxysalicylate to prepare a thermal coating liquid. I got it.

The surface of the thermal recording paper obtained as described above was treated with a calender, and the smoothness was 300±5 as Beck smoothness.
The temperature was adjusted to 0 seconds to obtain a heat-sensitive recording material.

The following birch paper was evaluated for thermal recording paper.

■Color density was determined by Kyocera printing tester at printing energy of 30.
Printing was performed at mJ/mm' and the color density was measured using a Macbeth densitometer. The higher this value is, the higher the sensitivity of the thermal recording paper is.

■Chemical resistance test is performed by impregnating filter paper with ethanol and castor oil and superimposing it on the colored surface of the recording paper obtained by the above method.
The degree of

The above results are shown in the table below.

Very good Excellent (slight changes observed) Practical (images can be read) Impossible (images are very difficult to read) As can be seen from the results in the table, the recording material of the present invention has high sensitivity. It can be seen that the product has extremely excellent performance, with no problems such as fogging caused by chemicals or decoloring of colored parts.

Claims (1)

[Scope of Claims] A heat-sensitive recording material comprising a heat-sensitive coloring layer containing an electron-donating colorless dye and an electron-accepting compound provided on a support, wherein the heat-sensitive coloring layer has an aryloxyalkyloxy group as a substituent. A heat-sensitive recording material comprising a salicylic acid derivative or a metal salt thereof, and a compound represented by the following general formula [I]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] (R^1, R^2, R^3 represent lower alkyl groups, l
represents an integer from 1 to 4. )