JP3025349B2 - Thermal recording material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive recording material, and more particularly to a heat-sensitive recording material having improved storage stability of a color image.

[0002]

2. Description of the Related Art Hitherto, a heat-sensitive recording material utilizing a color reaction between an electron-donating color-forming compound and an electron-accepting compound (a color developer) is well known (for example, Japanese Patent Publication No. Sho 43-4).
No. 160, JP-B-45-14039). Phenolic compounds are widely used as electron-accepting compounds. Among them, 2,2-bis (4′-hydroxyphenyl) propane (also called bisphenol A) is widely used because it is easily available at low cost. It's being used. However, a heat-sensitive recording material using bisphenol A as an electron-accepting compound has a problem that the storage stability of a color image is poor.

As electron accepting compounds, phenolic compounds other than bisphenol A, for example, 4-hydroxybenzoic acid esters (JP-A-56-144193, JP-B-1-30640), aralkyloxyphenols ( Japanese Patent Publication No. 2-31678, Japanese Unexamined Patent Publication No. Sho 6
No. 0-225789) and a heat-sensitive recording material using hydroxybenzophenones (JP-A-57-193388). However, when 4-hydroxybenzoic acid esters, for example, 4-hydroxybenzoic acid benzyl ester, are used as an electron-accepting compound, there is a disadvantage that the density of a color image decreases with time, and 4-hydroxybenzoate appears on the color image. There is a problem that white crystals of benzyl acid precipitate out and exhibit a state where the powder is wiped (so-called whitening phenomenon). Also, when aralkyloxyphenols, for example, 4-benzyloxyphenol, are used as the electron-accepting compound, there is a disadvantage that the color image density decreases with time. Furthermore, when hydroxybenzophenones, for example, 4-hydroxybenzophenone, are used as the electron-accepting compound, the storage stability (for example, wet heat resistance, water resistance) of the color image is poor, and it has practically sufficient performance. I can't say that. Against this background, there is a strong demand for a thermosensitive recording material having excellent storage stability of a color image.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-sensitive recording material in which the storage stability of a color image is remarkably improved.

[0005]

Means for Solving the Problems In order to meet the above-mentioned demands, the present inventors have conducted intensive studies on a heat-sensitive recording material, particularly an electron-accepting compound, and have reached the present invention. That is, the present invention relates to a heat-sensitive recording material containing an electron-donating color-forming compound and an electron-accepting compound, wherein at least one of the compounds represented by the general formula (I) (Formula 2) is used as the electron-accepting compound. The present invention relates to a thermosensitive recording material characterized by being used.

[0006]

Embedded image

In the compound represented by the general formula (I) according to the present invention, the hydroxyl group is para-position to the ether bond,
It may be in any of the meta position and the ortho position, and is preferably the para position or the meta position.

Particularly preferred examples of the compound represented by the general formula (I) according to the present invention include compounds represented by the following formulas (Ia) and (Ib). can do.

[0009]

Embedded image

The compounds represented by the formulas (Ia) and (Ib) can be prepared by known methods, for example, British Patent No. 121470.
It can be produced by the method described in Japanese Patent Publication No. That is, it can be produced by reacting 4,4'-dichlorodiphenylsulfone with hydroquinone or resorcinol in the presence of a base. Formula (Ia)
4,4'-bis (4-hydroxyphenyloxy) diphenylsulfone represented by the following formula:
4,4′-bis (3-hydroxyphenyloxy) diphenylsulfone represented by the formula (Ib) has a melting point of 154.
~ 157 ° C. In the heat-sensitive recording material of the present invention, the electron-accepting compound is usually used in an amount of 50 to 700 parts by weight, preferably 100 to 500 parts by weight, based on 100 parts by weight of the electron-donating color-forming compound.

The electron-donating color-forming compound used in the present invention is a colorless or pale-colored compound, such as a triarylmethane compound, a diarylmethane compound, a rhodamine-lactam compound, a fluoran compound, or an indolylphthalide compound. , Pyridine compounds, spiro compounds, fluorene compounds and the like. Examples of the triarylmethane compound include 3,3-bis (4-dimethylaminophenyl) -6-dimethylaminophthalide [crystal violet lactone], 3,3-bis (4-dimethylaminophenyl) phthalide, 3- ( 4-dimethylaminophenyl) -3- (1,3-dimethylindole-3-
Yl) phthalide, 3- (4-dimethylaminophenyl)
-3- (2-methylindol-3-yl) phthalide,
3,3-bis (9-ethylcarbazol-3-yl)-
6-dimethylaminophthalide, 3- (4-dimethylaminophenyl) -3- (1-methylpyrrol-3-yl)
-6-dimethylaminophthalide, 3,3-bis [2,2
-Bis (4-dimethylaminophenyl) ethenyl]-
4,5,6,7-tetrachlorophthalide and the like. Examples of the diarylmethane compound include 4,4-bis-dimethylaminobenzhydrin benzyl ether, N-halophenyl-leuco auramine, and N-2,4,5-trichlorophenyl leuco auramine. Examples of rhodamine-lactam compounds include rhodamine-B-anilinolactam, rhodamine- (4-nitroanilino) lactam, and rhodamine-B- (4-chloroanilino) lactam.

Examples of the fluoran compounds include 3,6-dimethoxyfluoran, 3-dimethylamino-7-methoxyfluoran, 3-diethylamino-6-methoxyfluoran, 3-diethylamino-7-methoxyfluoran, Diethylamino-7-chlorofluoran, 3-
Diethylamino-6-methyl-7-chlorofluoran,
3-diethylamino-6,7-dimethylfluoran, 3
-(N-cyclohexyl-NN-butyl) amino-7
-Methylfluorane, 3-diethylamino-7-dibenzylaminofluoran, 3-diethylamino-7-octylaminofluoran, 3-diethylamino-7-di-
n-hexylaminofluoran, 3-diethylamino-
7-anilinofluoran, 3-diethylamino-7-
(2-chloroanilino) fluoran, 3-diethylamino-7- (3-chloroanilino) fluoran, 3-diethylamino-7- (2,3-dichloroanilino) fluoran, 3-diethylamino-7- (3-trifluoromethylani Rhino) fluoran, 3-di-n-butylamino-7- (2-chloroanilino) fluoran, 3-diethylamino-6-chloro-7-anilinofluoran,

3-Di-n-butylamino-6-chloro-
7-anilinofluoran, 3-diethylamino-6-methoxy-7-anilinofluoran, 3-di-n-butylamino-6-ethoxy-7-anilinofluoran, 3-
Pyrrolidino-6-methyl-7-anilinofluoran, 3
-Morpholino-6-methyl-7-anilinofluoran,
3-dimethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-di-n-butylamino-6-methyl-
7-anilinofluoran, 3-di-n-pentylamino-6-methyl-7-anilinofluoran, 3-di-n-
Octylamino-6-methyl-7-anilinofluoran, 3- (N-ethyl-N-methyl) amino-6-methyl-7-anilinofluoran, 3- (Nn-propyl-N-methyl ) Amino-6-methyl-7-anilinofluoran, 3- (Nn-propyl-N-ethyl) amino-6-methyl-7-anilinofluoran, 3- (N-isopropyl-N-methyl ) Amino-6-methyl-7-anilinofluoran, 3- (Nn-butyl-N-methyl) amino-6-methyl-7-anilinofluoran, 3
-(NN-butyl-N-ethyl) amino-6-methyl-7-anilinofluoran, 3- (NN-butyl-N
-N-propyl) amino-6-methyl-7-anilinofluoran,

3- (N-isobutyl-N-methyl) amino-6-methyl-7-anilinofluoran, 3- (N-
Isobutyl-N-ethyl) amino-6-methyl-7-anilinofluoran, 3- (N-isopentyl-N-ethyl) amino-6-methyl-7-anilinofluoran, 3
-(Nn-hexyl-N-ethyl) amino-6-methyl-7-anilinofluoran, 3- (Nn-octyl-N-ethyl) amino-6-methyl-7-anilinofluoran , 3- (N-cyclohexyl-N-methyl) amino-6-methyl-7-anilinofluoran, 3- (N-
Cyclohexyl-N-n-propyl) amino-6-methyl-7-anilinofluoran, 3- (N-cyclohexyl-N-n-butyl) amino-6-methyl-7-anilinofluoran, 3- ( N-cyclohexyl-NN-pentyl) amino-6-methyl-7-anilinofluoran, 3- (N-cyclohexyl-Nn-hexyl) amino-6-methyl-7-anilinofluoran, 3 − (N
-Cyclohexyl-N-n-heptyl) amino-6-methyl-7-anilinofluoran, 3- (N-cyclohexyl-Nn-octyl) amino-6-methyl-7-anilinofluoran, 3- (N-cyclohexyl-Nn
-Decyl) amino-6-methyl-7-anilinofluoran, 3- (N-2'-methoxyethyl-N-methyl) amino-6-methyl-7-anilinofluoran, 3- (N
-2'-methoxyethyl-N-ethyl) amino-6-methyl-7-anilinofluoran,

3- (N-2'-ethoxyethyl-N-methyl) amino-6-methyl-7-anilinofluoran,
3- (N-2'-ethoxyethyl-N-ethyl) amino-6-methyl-7-anilinofluoran, 3- (N-
3'-methoxypropyl-N-methyl) amino-6-methyl-7-anilinofluoran, 3- (N-3'-ethoxypropyl-N-methyl) amino-6-methyl-7-
Anilinofluoran, 3- (N-2′-methoxyethyl-N-isobutyl) amino-6-methyl-7-anilinofluoran, 3- (N-2′-tetrahydrofurfuryl-N-ethyl) amino -6-methyl-7-anilinofluoran, 3- (N- (4'-methylphenyl) -N-ethyl) amino-6-methyl-7-anilinofluoran,
3-diethylamino-6-ethyl-7-anilinofluoran, 3-di-ethylamino-6-methyl-7-
(2 ′, 5′-dimethylphenylamino) fluoran,
3-di-n-butylamino-6-methyl-7- (2 ′,
5'-dimethylphenylamino) fluoran, 3-di-
n-butylamino-7- (2 ', 5'-dimethylphenylamino) fluoran, 2,2-bis [4'-(3-
(N-cyclohexyl-N-methyl) amino-6-methylfluoran) -7-ylaminophenyl] propane.

The indolylphthalide compounds include:
3,3-bis (1-ethyl-2-methylindole-3
-Yl) phthalide, 3,3-bis (1-octyl-2-
Methylindol-3-yl) phthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) phthalide, 3
-(2-ethoxy-4-dibutylaminophenyl) -3
-(1-ethyl-2-methylindol-3-yl) phthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-octyl-2-methylindole-
3-yl) phthalide and the like.

Examples of the pyridine compound include 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-octyl-2-methylindol-3-yl) -4 or 7-azaphthalide, 3- (2 -Ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4 or 7-azaphthalide, 3-
(2-hexyloxy-4-diethylaminophenyl)
-3- (1-Ethyl-2-methylindol-3-yl) -4 or 7-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-
2-phenylindol-3-yl) -4 or 7-azaphthalide, 3- (2-butoxy-4-diethylaminophenyl) -3- (1-ethyl-2-phenylindol-3-yl) -4 Or 7-azaphthalide.

The spiro compounds include 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3-phenyl-spiro-dinaphthopyran,
Benzyl-spiro-dinaphthopyran, 3-methyl-naphtho- (3-methoxybenzo) spiropyran, 3-propyl-spiro-dibenzopyran and the like. As the fluorene compound, 3 ′, 6′-bisdiethylamino-5
-Diethylaminospiro (isobenzofuran-1,9 '
-Fluoren) -3-one, 3 ', 6'-bisdiethylamino-7-diethylamino-2-methylspiro (1,
3-benzoxazine-4,9'-fluorene). These electron-donating color-forming compounds may be used alone or as a mixture of two or more kinds for the purpose of adjusting the color tone of a color-formed image or obtaining a multicolor heat-sensitive recording material.

The heat-sensitive recording material of the present invention is characterized by containing at least one compound represented by the general formula (I) as an electron-accepting compound. Other electron-accepting compounds other than the compound represented by the general formula (I) can be used in combination as long as they do not impair. In this case, the proportion of the compound represented by the general formula (I) in the total electron-accepting compound is usually 20% by weight or more, preferably 50% by weight or more. Examples of the electron-accepting compound other than the compound represented by the general formula (I) include organic electron-accepting compounds such as phenol derivatives, organic acids or metal salts, complexes, and urea derivatives, and inorganic electron-accepting compounds such as acid clay. Is mentioned.

Specific examples of these compounds include 4-
tert-butylphenol, 4-tert-octylphenol, 4-phenylphenol, 1-naphthol, 2-naphthol, hydroquinone, resorcinol, 4-tert-octylcatechol, 2,2′-dihydroxydiphenyl, 2,2-bis (4 ′ -Hydroxyphenyl) propane (also called bisphenol A),
1,1-bis (4′-hydroxyphenyl) cyclohexane, 2,2′-bis (4′-hydroxy-3′-methylphenyl) propane, 2,2-bis (4′-hydroxyphenyl) acetic acid ethyl ester, 4,4- (4′-hydroxyphenyl) pentanoic acid-n-butyl ester,
4-hydroxybenzoic acid benzyl ester, 4-hydroxybenzoic acid phenethyl ester, 2,4-dihydroxybenzoic acid phenoxyethyl ester, 4-hydroxyphthalic acid dimethyl, hydroquinone monobenzyl ether, bis (3-methyl-4-hydroxyphenyl) Sulfide, bis (2-methyl-4-hydroxyphenyl)
Sulfide, bis (2-phenyl-4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) sulfone, 4-hydroxy-4′-isopropoxydiphenylsulfone, 4-hydroxy-4 '-N-butoxydiphenylsulfone, 3,4-dihydroxy-4'-methyldiphenylsulfone, bis (2-hydroxy-4-tert
-Butylphenyl) sulfone, bis (2-hydroxy-4-chlorophenyl) sulfone, 4-hydroxybenzophenone, 2,4-dihydroxybenzophenone,
Phenol derivatives such as 1,7-di (4-hydroxyphenylthio) -3,5 dioxaheptane and 1,5-di (4-hydroxyphenylthio) -3oxapentane;

Salicylic acid, 3-isopropylsalicylic acid, 3-cyclohexylsalicylic acid, 3,5-di-te
rt-butylsalicylic acid, 3,5-di-α-methylbenzylsalicylic acid, 3-methyl-5-α-methylbenzylsalicylic acid, 5- [2 ′-(4-methoxyphenyloxy) ethyloxy] salicylic acid, 2-hydroxy- Organic acids such as 3-naphthoic acid, 2-hydroxy-6-naphthoic acid, monobenzyl phthalate and monophenyl phthalate, or metal salts thereof (for example, metal salts such as nickel, zinc, aluminum and calcium); Complexes such as zinc thiocyanate antipyrine complex, acetylacetone molybdate complex, phenylthiourea, di (3-trifluoromethylphenyl) thiourea,
Organic electron-accepting compounds such as urea derivatives such as 1,4-di (3'-chlorophenyl) -3-thiosemicarbazide, acid clay, attapulgite, activated clay, aluminum chloride, zinc chloride, zinc bromide, aluminum chloride, etc. Inorganic electron accepting compounds can be mentioned as preferred compounds. In particular, phenol derivatives are preferred electron-accepting compounds. These electron accepting compounds may be used alone or in combination of two or more.

Further, if desired, a heat-fusible compound (compound having a melting point of about 60 to 150 ° C.) may be added to the heat-sensitive recording material of the present invention as a sensitizer for the purpose of improving color sensitivity. Is also good. In this case, the amount of the heat-fusible compound is usually 10 to 700 parts by weight, preferably 20 to 500 parts by weight, based on 100 parts by weight of the electron-donating color-forming compound. Specific examples of such a heat-fusible compound include, for example, stearic acid amide, palmitic acid amide, stearyl urea, N
-Nitrogen-containing compounds such as -ethylcarbazole and 4-methoxydiphenylamine, benzyl 4-benzyloxybenzoate, phenyl 2-naphthoate, 1-
Hydroxy-2-naphthoic acid phenyl ester, oxalic acid dibenzyl ester, oxalic acid di (4-methylbenzyl) ester, oxalic acid di (4-chlorobenzyl) ester, glutaric acid diphenacyl ester, di (4-methylphenyl) ) Carbonates, ester compounds such as terephthalic acid dibenzyl ester, hydrocarbon compounds such as 4-benzylbiphenyl, m-terphenyl, fluorene and fluoranthene, 2-benzyloxynaphthalene,
2- (4'-methylbenzyloxy) naphthalene, 1,
4-diethoxynaphthalene, 1,2-bis (3'-methylphenoxy) ethane, 1-phenoxy-2- (4-ethylphenoxy) ethane, 4- (4'-methylphenoxy) biphenyl, 1,4-bis Examples thereof include ether compounds such as (2'-chlorobenzyloxy) benzene, 4,4'-di-n-butoxydiphenylsulfone, and 1,4-bis (3'-methylphenyloxymethyl) benzene. Particularly, an ester compound, a hydrocarbon compound or an ether compound is a preferred heat-fusible compound, and among them, di (4-methylbenzyl) oxalate is preferred.
Esters, 4-benzylbiphenyl, m-terphenyl, 2-benzyloxynaphthalene, 1,2-bis (3'-methylphenoxy) ethane and 4- (4'-methylphenoxy) biphenyl are preferred thermofusible compounds. is there. These heat-fusible compounds may be used alone or in combination of two or more.

The heat-sensitive recording material of the present invention can be manufactured by a known method without using a special method. Generally, the electron-donating color-forming compound and the electron-accepting compound are each pulverized in a water-soluble binder to a particle size of usually 3 μm or less, preferably 1.5 μm or less, by means such as a ball mill or a sand mill. It can be dispersed and mixed to prepare a coating liquid. Specific examples of the water-soluble binder include, for example, polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, epichlorohydrin modified polyamide, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, isobutylene-anhydride. Examples include maleic acid copolymer, polyacrylic acid, polyacrylamide, methylol-modified polyacrylamide, starch derivative, casein, gelatin, methylcellulose, carboxymethylcellulose, gum arabic, and carboxyl-modified polyvinyl alcohol.

In the heat-sensitive recording material of the present invention, the method for forming the recording layer is not particularly limited, and it can be formed according to a conventionally known technique. For example, a coating solution for a heat-sensitive recording layer is coated on a support with an appropriate coating device such as an air knife coater, a blade coater, a bar coater, a gravure coater, a curtain coater, and a wire bar, and dried to form a recording layer. be able to. Is not particularly limited with respect to the coating amount of the coating liquid, generally dry weight 1.5~12g / m ^2, preferably in the range of 2.5~10g / m ^2. Paper, plastic sheet, synthetic paper, etc. are used as the support.

Further, a pigment, a water-insoluble binder, a metal soap, a wax, a surfactant, an ultraviolet absorber, an antifoaming agent, etc. may be added to the recording layer of the heat-sensitive recording material of the present invention, if necessary. Is also good. Examples of pigments include zinc oxide, calcium carbonate, magnesium carbonate, barium carbonate, barium sulfate, titanium oxide, talc, fluorite, kaolin, diatomaceous earth, aluminum hydroxide, magnesium hydroxide, alumina, silica, amorphous silica, and urea. -Formalin filler,
Polyethylene particles, cellulose fillers and the like are used. As the water-insoluble binder, synthetic rubber latex or synthetic resin emulsion is generally used, and styrene-butadiene rubber latex, acrylonitrile-
Butadiene latex, methyl acrylate-butadiene rubber latex, vinyl acetate emulsion and the like are used. As the metal soap, higher fatty acid metal salts are used, such as zinc stearate, calcium stearate, and aluminum stearate. Examples of the wax include paraffin wax, microcrystalline wax, carboxy-modified paraffin wax, carnauba wax, polyethylene wax, polystyrene wax, and higher fatty acid esters. Examples of the surfactant include a sulfosuccinic acid-based alkali metal salt, a fluorine-containing surfactant, and the like. Examples of the ultraviolet absorber include cinnamic acid derivatives, benzophenone derivatives, and benzotriazolylphenol derivatives. In addition,
If necessary, a protective layer may be provided on the front and / or back surface of the heat-sensitive recording layer, or an undercoat layer may be provided between the support and the heat-sensitive recording layer. Various known techniques in the production method of the above can be provided.

[0026]

(Method for preparing dispersion for heat-sensitive recording layer)

(Solution A composition) Electron-donating color-forming compound 10 g Polyvinyl alcohol (Kuraray-117) 10% aqueous solution 10 g Water 80 g total 100 g (Solution B composition) Electron accepting compound 20 g Light calcium carbonate (Okutama Kogyo, TP-123) 40 g A 10% aqueous solution of polyvinyl alcohol (Kuraray-117) 60 g Water 130 g Total 250 g Each of the solutions A and B was dispersed by a sand grinding mill so that the average particle diameter became 1.5 μm or less to prepare a dispersion.

Examples 1 to 8 Using an electron-donating color-forming compound and an electron-accepting compound [compound represented by formula (I)] shown in Table 1,
Each dispersion of 100 g of solution A and 250 g of solution B prepared by the above method was mixed with 23 g of 30% paraffin wax,
This was coated on high-quality paper so that the dry coating amount was 5.0 ± 0.5 g / m ^2, and dried to prepare a thermosensitive recording paper.

[0028]

[Table 1]

Comparative Examples 1 to 4 A liquid 100 prepared by the above method using the electron-donating color-forming compound and the electron-accepting compound shown in Table 2.
g, 250 g of each dispersion of solution B and 23 g of 30% paraffin wax, and apply the mixture to a high-quality paper so that the dry coating amount is 5.0 ± 0.5 g / m ^2, and then the mixture is dried. Recording paper was created.

[0030]

[Table 2] For each thermal recording paper created in the examples and comparative examples,
Using a thermal paper coloring device (TH-PMD manufactured by Okura Electric)
After forming a color image having a color density of 0.9 as measured by a Macbeth densitometer (TR-524 type), the image area is examined for the presence of whitening phenomenon, and further subjected to the wet heat resistance test and the water resistance test by the following evaluation methods. And the image storage stability of each thermosensitive recording paper was examined. The results are shown in Table 3. [Evaluation Method of Thermal Recording Paper] (Storage Stability Test of Colored Image) Moisture / heat resistance test: A Macbeth densitometer was used to measure the density of the color image after each thermal recording paper was stored at 60 ° C. and 90% relative humidity for 24 hours. (TR-524) to determine the residual ratio of the color image. Water resistance test: The density of a color image after each heat-sensitive recording paper is stored in water at 25 ° C. for 24 hours is measured using a Macbeth densitometer to determine the residual ratio of the color image. The residual rate of the color image after each test is determined by the following equation.

[0031] The larger the value, the better the storage stability of the color image.

[0032]

[Table 3] From Table 3, it can be seen that the heat-sensitive recording material of the present invention using the compound represented by the general formula (I) as the electron-accepting compound has a higher color development than the heat-sensitive recording material prepared using the conventional electron-accepting compound. It is clear that the storage stability of the image (moisture heat resistance and water resistance) is very good.

[0033]

According to the present invention, a heat-sensitive recording material having excellent storage stability such as wet heat resistance and water resistance of a color image can be obtained.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kazuyoshi Yoshikawa 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Akihiro Yamaguchi 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Examiner Hiromi Matsushima (56) References JP-A-57-178793 (JP, A) JP-A-1-288484 (JP, A) International Publication 84/2882 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41M 5/28-5/34 CA (STN) REGISTRY (STN)

Claims (1)

(57) [Claims] 1. A thermosensitive recording material containing an electron-donating color-forming compound and an electron-accepting compound, wherein said electron-accepting compound is represented by the general formula (I): A heat-sensitive recording material comprising at least one compound represented by the formula: