JPH0615957A - Heat-sensitive recording material - Google Patents

Abstract

PURPOSE:To obtain a heat-sensitive recording material with less blushing of the base surface under a high temp. and high humidity condition and with high water resistance by laminating a heat-sensitive color developing layer contg. a color developing dye, an acidic substance and a specified epoxy resin on a substrate. CONSTITUTION:A color developing dye, an acidic substance and an epoxy resin of formula I (wherein R1 and R2 are each a residue wherein hydroxyl groups are excluded from a compd. with two or more phenolic hydroxyl groups and Z1 and Z2 are each zero or an integer of 1 or larger and M is a glycidyl group or a hydrogen and n is an integer of 1 or larger) each with a specified amt. are separately ground and dispersed with a binder by using a dispersing machine such as a ball mill and then, they are mixed together to prepare a heat-sensitive color developing layer coating liq. This heat-sensitive color developing coating liq. is applied on a substrate such as a paper, a plastic sheet and a synthetic paper and is dried to laminate a heat-sensitive color developing layer and to obtain a heat-sensitive recording material. In addition, if neccesary, an intermediate layer can be provided between the heat-sensitive color developing layer l. and the substrate.

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 excellent in storage stability of a color image.

[0002]

2. Description of the Related Art A heat-sensitive recording material using a colorless or light-colored color-forming substance and a color-developing substance capable of coloring the color-forming substance under heat is disclosed in JP-B-43-4160 and JP-B-451403.
It was announced in No. 9 and has been put to practical use. Generally, in a heat-sensitive recording material, a leuco dye and a developer such as a phenolic substance are separately dispersed in fine particles, and then both are mixed, and a binder, a sensitizer, a filler, a lubricant, etc. are added to the mixture. It forms a coating liquid by adding an agent and is applied to a support such as paper, film, synthetic paper, etc. Color recording by a chemical reaction that occurs when one or both of the leuco dye and the developer melt and contact by heating. In general, a sheet-shaped heat-sensitive recording material is prepared. A thermal printer or the like having a built-in thermal head is used for color development of such a thermal recording sheet. Compared to other recording methods, this heat-sensitive recording method is (1) no noise is generated during recording, (2) there is no need for developing and fixing, (3) maintenance-free, (4)
It is widely used in the field of facsimiles, computer output, printers such as calculators, recorders for medical measurement, ticket vending machines, thermosensitive recording labels, etc. due to the fact that machines are relatively inexpensive. .

[0003] Among these fields of use, labels are being used with the expansion of POS systems in retail stores, supermarkets, etc., and their use is increasing in train tickets for station automation systems. However, their use is a major drawback in that the color image disappears or fades due to contact with plastic sheets or water wetting.

As a method for solving such a drawback, a method of coating an aqueous emulsion of a chemically resistant resin on the heat-sensitive recording layer (JP-A-54-128347) and a method of coating a water-soluble polymer compound such as polyvinyl alcohol. (Actual development No. 50-125354), or a method of using a bisphenol derivative for the purpose of improving water resistance and storability of a color image (JP-A-57-195691, JP-A-57-20519).
1), a method using a novolac epoxy resin (Japanese Patent Laid-Open No. 2-289378), etc. have been proposed, but no sufficiently satisfactory effect has been obtained.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art. That is,
To provide a heat-sensitive recording material having high water resistance and high plasticizer property, which is unlikely to be discolored or discolored due to wetness of a color image or contact with a plastic film or the like, has little background fog under high temperature and high humidity conditions. It is in.

[0006]

The inventors of the present invention have completed the present invention as a result of various studies to achieve the above object. That is, the present invention provides a color-forming recording material comprising a colorless or light-colored electron-donating color-forming dye and an acidic substance, and at least one of the epoxy resins represented by the formula (1).
The present invention provides a heat-sensitive recording material containing at least one species.

[0007]

[Chemical 2]

(In the formula, R ₁ and R ₂ are the same or different and represent a residue in which a hydroxyl group of a compound having two or more phenolic hydroxyl groups is removed. Z ₁ and Z ₂ are the same or different and are 0 or 1 or more. And the sum of Z ₁ and Z ₂ is 1 or more, M is a glycidyl group or a hydrogen atom, and n is an integer of 1 or more, provided that when n is 1, M is always a glycidyl group. And when n is 2 or more, at least one is a glycidyl group.)

The epoxy resin of the present invention is obtained, for example, by reacting the alcoholic hydroxyl group of the epoxy resin represented by the formula (2) with epichlorohydrin in the presence of a quaternary ammonium salt or dimethyl sulfoxide.

[0010]

[Chemical 3]

(Wherein R ₁ , R ₂ , Z ₁ , Z ₂ , M and n have the same meanings as in the above formula (1).) As the epoxy resin represented by the formula (1) For example, as R ₁ and R ₂ in the formula (1) represents a residue in which a hydroxyl group of a compound having three or more phenolic hydroxyl groups is removed,

[0012]

[Chemical 4]

[0013]

[Chemical 5]

[0014]

[Chemical 6]

[0015]

[Chemical 7]

[0016]

[Chemical 8]

[0017]

[Chemical 9]

[0018]

[Chemical 10]

[0019]

[Chemical 11]

[0020]

[Chemical 12]

[0021]

[Chemical 13]

[0022]

[Chemical 14]

(Equation p indicates 0 or an integer of 1 or more)

[0024]

[Chemical 15]

(Expression note p indicates an integer of 0 or 1 or more)

A compound in which R ₁ and R ₂ represent a residue obtained by removing a hydroxyl group of a compound having two phenolic hydroxyl groups is represented by the following formula:

[0027]

[Chemical 16]

[0028]

[Chemical 17]

[0029]

[Chemical 18]

[0030]

[Chemical 19]

[0031]

[Chemical 20]

[0032]

[Chemical 21]

[0033]

[Chemical formula 22]

[0034]

[Chemical formula 23]

[0035]

[Chemical formula 24]

[0036]

[Chemical 25]

[0037]

[Chemical formula 26]

[0038]

[Chemical 27]

[0039]

[Chemical 28]

[0040]

[Chemical 29]

[0041]

[Chemical 30]

[0042]

[Chemical 31]

[0043]

[Chemical 32]

[0044]

[Chemical 33]

[0045]

[Chemical 34]

[0046]

[Chemical 35]

[0047]

[Chemical 36]

[0048]

[Chemical 37]

[0049]

[Chemical 38]

[0050]

[Chemical Formula 39]

[0051]

[Chemical 40]

[0052]

[Chemical 41]

[0053]

[Chemical 42]

[0054]

[Chemical 43]

[0055]

[Chemical 44]

[0056]

[Chemical formula 45]

[0057]

[Chemical formula 46]

[0058]

[Chemical 47]

[0059]

[Chemical 48]

[0060]

[Chemical 49]

[0061]

[Chemical 50]

[0062]

[Chemical 51]

[0063]

[Chemical 52]

[0064]

[Chemical 53]

[0065]

[Chemical 54]

[0066]

[Chemical 55]

However, the present invention is not limited to these. In addition, R ₁ and R ₂ in the formula (1) may include different ones.

N in the formula (1) represents 0 or an integer of 1 or more, preferably 0 to 13, particularly preferably 0 to
It is 6. If it exceeds 13, the softening point of the epoxy resin may be increased and the effect of improving the storage stability may be lowered.

If the softening point is too low, the whiteness of the thermal recording paper may decrease. The preferred softening point is 60 to 15
An epoxy resin having a softening point of 0 degree, particularly preferably 80 to 120 degrees.

The epoxy resin of the present invention is usually contained not only in the thermosensitive color developing layer but also in an intermediate layer provided between the support and the thermosensitive color developing layer or in a protective layer provided on the thermosensitive color developing layer. It is possible. As a result, a heat-sensitive recording paper having improved plasticizer resistance and oil resistance and free from background fog can be obtained.

In the heat-sensitive recording material of the present invention, the following (A) color-forming compound, (B) color-developing compound,
(C) The thermosensitive coloring layer is adjusted with a binder and optionally a filler, a heat-fusible compound and a surfactant,
The compound represented by the formula (1) is contained in the thermosensitive coloring layer in an amount of 1-50.
The weight percentage is preferably 2 to 30%.

(A) Examples of chromogenic compounds Fluoran compounds, triarylmethane compounds, spiropyran compounds, diphenylmethane compounds, thiazine compounds, lactam compounds, fluorene compounds, etc. are mentioned, and specific examples thereof include The following compounds may be mentioned.

Fluoran compounds; 2-anilino-3-
Methyl-6-diethylaminofluorane, 2-anilino-3-methyl-6-dibutylaminofluorane, 2-
Anilino-3-methyl-6-dipentylaminofluorane, 2-anilino-3-methyl-6- (N-methyl-N
-Cyclohexylamino) fluorane, 2-anilino-
3-Methyl-6- (N-ethyl-N-isopentylamino) fluorane, 2- (p-chloroanilino) -3-methyl-6-diethylaminofluorane, 2- (p-fluoroanilino) -3-methyl -6-Diethylaminofluorane, 2-anilino-3-methyl-6- (p-toluidinoethylamino) fluorane, 2- (p-toluidino) -3-methyl-6-diethylaminofluorane, 2
-(O-chloroanilino) -6-diethylaminofluorane, 2- (o-chloroanilino) -6-dibutylaminofluorane, 2- (o-fluoroanilino) -6-diethylaminofluorane, 2- (o-fluoro) Anilino) -6-dibutylaminofluorane, 2-anilino-
3-methyl-6-piperidinofluorane, 2-anilino-3-methyl-6-pyrrolidinofluorane, 2-ethoxyethylamino-3-chloro-6-diethylaminofluorane, 2-anilino-3-chloro -6-diethylaminofluorane, 2-chloro-6-diethylaminofluorane, 2-methyl-6-diethylaminofluorane, 2
-Anilino-3-methyl-6- (N-isobutyl-N-
Ethylamino) fluorane, 2-anilino-3-methyl-6 (N-ethyl- (N-3-ethoxypropyl) amino) fluorane, 2-anilino-3-methyl-6- (N
-Ethyl-N-hexylamino) fluorane, etc.,

Triarylmethane compounds; 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) phthalide, 3- (p-dimethylaminophenyl) ) −
Spiropyran compounds such as 3- (1,2-dimethylaminoindole) -3-isophthalide; 3-methyl-3-spirodinaphthopyran, -1,3,3-trimethyl-6-nitro-
8'-methoxyspiro (indoline-2,2'-benzopyran) and other diphenylmethane compounds; N-halophenyl-leukoauramine and the like,

Thiazine compounds; benzoyl leuco methylene blue; lactam compounds; rhodamine-B-anilinolactam; fluorene compounds; 3,6-bis (dimethylamino)
Fluorene spiro (9,3 ′)-6- ′ dimethylaminophthalide, [3,6-bis (dimethylamino) fluorene spiro (9,3 ′)-6′-pyrrolidinophthalide],
[3-Dimethylamino-6-diethylaminofluorenspiro (9,3 ′)-6′-pyrrolidinophthalide] and the like can be mentioned. These color forming compounds may be used alone or as a mixture.

(B) Examples of color-developing compounds α-naphthol, β-naphthol, p-octylphenol, 4-t-octylphenol, pt-butylphenol, p-phenylphenol, 1,1'-bis (p- Hydroxyphenyl) propane, 2,2-bis (p-hydroxyphenyl) propane, 2,2′-bis (p-hydroxyphenyl) butane, 1,1′-bis (p-hydroxyphenyl) cyclohexane, 4,4 ′
-Thiobisphenol, 4,4'-cyclohexylidene diphenol, 4,4'-sulfonyldiphenol,
4,4'-Sulfonyl-bis (2-allylphenol), 2,2'-bis (2,5-dibromo-4-hydroxyphenyl) propane, 4,4'-isopropylidenebis (2-t-butylphenol) , 2,2'-methylenebis (4-chlorophenol), 4-hydroxy-
4'-isopropoxydiphenyl sulfone, bis (4-
Phenolic compounds such as hydroxyphenyl) methyl acetate, bis (4-hydroxyphenyl) butyl acetate, bis (4-hydroxyphenyl) benzyl acetate, benzyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, 4-hydroxyphthalic acid Dibenzyl, dimethyl 4-hydroxyphthalate, ethyl 5-hydroxyisophthalate, 3,5-di-t-butylsalicylic acid, 3,5-di-
Examples thereof include aromatic carboxylic acid derivatives such as α-methylbenzyl salicylic acid, aromatic carboxylic acids and polyvalent metal salts thereof.

(C) Examples of binders Methylcellulose, methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, cellulose, polyvinyl alcohol (PVA), carboxy group-modified polyvinyl alcohol, sulfonic acid group-modified polyvinyl alcohol, polyvinylpyrrolidone, poly Acrylamide, polyacrylic acid, starch and its derivatives, aqueous solutions of casein, gelatin, etc., isoprene rubber, alkali salt of styrene / maleic anhydride copolymer, alkali salt of iso (or diiso) butylene / maleic anhydride copolymer, etc. Water soluble or polyvinyl acetate, vinyl chloride / vinyl acetate copolymer, polystyrene, polyacrylic acid ester, polyurethane, styrene / butadiene (SB) Polymer, carboxylated styrene / butadiene (SB) copolymer,
A styrene / butadiene / acrylic acid type copolymer, a water-soluble emulsion such as colloidal silica / acrylic resin composite particles, and the like are used.

Examples of Other Additives Examples of fillers include calcium carbonate, magnesium carbonate, magnesium oxide, silica, white carbon, talc, clay, alumina, magnesium hydroxide, aluminum hydroxide, aluminum oxide, barium sulfate, polystyrene. Resin, urea-formalin resin and the like.

Examples of the heat-fusible compound include waxes such as animal and vegetable wax, polyethylene wax and synthetic wax, higher fatty acids, higher fatty acid amides, higher fatty acid metal salts, acetylated aromatic amines, aromatic ether compounds and biphenyls. Examples thereof include derivatives that are solid at room temperature and have a melting point of about 80 ° C. or higher. In addition, lubricants such as zinc stearate, calcium stearate and aluminum stearate, various surfactants, antifoaming agents and the like are added as necessary.

The heat-sensitive recording material of the present invention is prepared using the above-mentioned material, for example, by the following method. That is, according to a conventional method, first, a color-forming compound, a color-developing compound, and a compound represented by the formula (1) are separately added together with a binder or, if necessary, other additives, in a ball mill, an attritor,
After pulverizing and dispersing with a disperser such as a sand mill (the compound of the formula (1) may be mixed with the color-forming compound or the color-developing compound in advance for dispersion), and mixed to form a thermosensitive color-forming layer coating liquid. Prepared and coated on a support such as paper, plastic sheet, synthetic paper, etc. by a bar coater, a blade coater, etc. so that the dry weight is usually 1 to 20 g / m ² (ratio of the color-forming compound and the color-developing compound). Is usually 1: 1 to 1:10 by dry weight ratio) to obtain the heat-sensitive recording material of the present invention.

If necessary, an intermediate layer may be provided between the heat-sensitive color developing layer and the support, or an overcoat layer may be provided on the heat-sensitive color developing layer. The heat-sensitive recording material of the present invention containing the compound of formula (1) is superior in the storage stability of a color image as compared with the conventionally known materials.

[0082]

EXAMPLES The present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. In the examples, "part" indicates part by weight.

Example 1 A mixture having the following composition was pulverized for 30 minutes using a sand grinder, and liquids [A], [B] and [C] were respectively obtained.
A liquid was prepared. Liquid [A]: 2-anilino-3-methyl-6-25 parts Dibutylaminofluorane 25% PVA aqueous solution 20 parts Water 55 parts [B] liquid: Bisphenol A 8 parts 4-Methylphenylmesitylene sulfonate 8 parts Calcium carbonate 13.5 parts Carboxylated SB latex (50%) 7 parts 25% PVA aqueous solution 5 parts Water 58.5 parts [C] liquid: Epoxy resin No. 1. 25 parts 25% PVA aqueous solution 20 parts water 55 parts Epoxy resin No. 1 used here. Is R ₁ of the formula (1)
And R ₂ is

[0084]

[Chemical 56]

In the formula (1), the average n is 1.5 and M is an epoxy resin having a softening point of 82 ° C., all of which is a glycidyl group.

Next, the above [A] solution: [B] solution: [C] solution = 6 parts: 74 parts: 20 parts were mixed to prepare a thermosensitive color developing layer coating solution having a basis weight of 50 g / m ² . 3 on the fine paper
The heat-sensitive color forming layer was provided by coating and drying so as to give 0 g / m ² . Further, a 10% PVA aqueous solution was applied and dried on the thermosensitive coloring layer so that the coating amount after drying was 3 g / m ² , to obtain a thermosensitive material of the present invention.

Example 2 [D] liquid having the following crushing composition in place of [A] liquid in Example 1 [D] liquid: 2-o-fluoroanilino-6-25 parts dibutylaminofluorane 25% PVA aqueous solution 20 parts Water 55 parts [D] liquid: [B] liquid: [C] liquid: water = 6 parts: 74
Parts: 10 parts: mixed at a ratio of 10 parts to prepare a thermosensitive color developing layer coating liquid, and the liquid amount is 30 g on a high quality paper having a basis weight of 50 g / m ^2.
The coating was performed so that the coating amount would be / m ^2, and the coating was dried to provide a thermosensitive coloring layer. Further, a 10% PVA aqueous solution was applied and dried on the thermosensitive coloring layer so that the coating amount after drying was 3 g / m ² , to obtain a thermosensitive material of the present invention.

Example 3 Epoxy resin No. 1 of the liquid [C] in Example 1 was used. Instead of epoxy resin No2. Was used in the same manner as in Example 1 to obtain a heat-sensitive material of the present invention. Epoxy resin No2. Is the formula (1)
R ₁ and R ₂ of

[0089]

[Chemical 57]

In the formula (1), the average n is 2.1 and M is an epoxy resin having a softening point of 98 ° C., all of which is a glycidyl group.

Example 4 Epoxy resin No. 1 of the liquid [C] in Example 1 was used. Instead of epoxy resin No3. Was used in the same manner as in Example 1 to obtain a heat-sensitive material of the present invention. Epoxy resin No3. Is the formula (1)
R ₁ and R _{2 of} have an average p of 4.2

[0092]

[Chemical 58]

In the formula (1), the average n is 1.5 and M is an epoxy resin having a glycidyl group and a softening point of 90 ° C.

Example 5 Epoxy resin No. 1 of the liquid [C] in Example 1 was used. Instead of epoxy resin No4. Was used in the same manner as in Example 1 to obtain a heat-sensitive material of the present invention. No4. Is R ₁ and R ₂ of the formula (1), and the average p is 4.2.

[0095]

[Chemical 59]

An epoxy resin having a softening point of 100 ° C. and having an average n of the formula (1) of 1.5 and 0.8 of M are glycidyl groups.

Example 6 In Example 1, the epoxy resin No. Instead of epoxy resin No5. Was used in the same manner as in Example 1 to obtain a heat-sensitive material of the present invention. No5. Where R ₁ and R ₂ in formula (1) are

[0098]

[Chemical 60]

In the epoxy resin having a softening point of 101 ° C., the average n of the formula (1) is 1.9 and 0.8 of M are glycidyl groups.

Example 7 The heat-sensitive material of the present invention was prepared in the same manner as in Example 1 except that 4,4'-sulfonylbis (2-allylphenol) was used instead of bisphenol A in the liquid (B) of Example 1. A recording material was obtained.

Example 8 Instead of bisphenol A in the liquid (B) of Example 1, 4
A thermosensitive recording material of the present invention was obtained in the same manner as in Example 1 except that -hydroxy-4'-isopropoxydiphenyl sulfone was used.

Example 9 A thermosensitive recording material of the present invention was obtained in the same manner as in Example 1 except that benzyl bis (4-hydroxyphenyl) acetate was used in place of bisphenol A in the liquid (B) of Example 1. It was

Example 10 2-anilino-3-methyl-6 in the liquid (A) of Example 1
2-anilino-instead of dibutylaminofluorane
A heat-sensitive recording material of the present invention was obtained in the same manner as in Example 1 except that 3-methyl-6- (N-ethyl-N-isopentylamino) fluorane was used.

Comparative Example 1 A thermosensitive recording material was obtained in the same manner as in Example 1 except that the liquid [C] was not used.

Comparative Example 2 A cresol novolac type epoxy resin Nippon Kayaku Co., Ltd. in place of the epoxy resin No1 of the liquid [C] in Example 1;
A heat-sensitive material of the present invention was obtained in the same manner as in Example 1 by using the trade name EOCN-104S (softening point 94 ° C).

Comparative Example 3 A cresol novolac type epoxy resin was used instead of the epoxy resin No1 of the liquid [C] in Example 1, Ciba-Geigy Co .;
A heat-sensitive material of the present invention was obtained in the same manner as in Example 1 using the trade name ECN-299 (softening point 97 °). Using the heat-sensitive recording material of the present invention and the heat-sensitive recording material for comparison obtained as described above, the following quality evaluation test was carried out.

Table 1 Quality performance test results Background 1) Color density 2) Heat resistance 3) Water resistance 4) Background image area Image area Example 1 0.06 1.33 0.07 1.33 1.13 Example 2 0.05 1.29 0.06 1.29 1.11 Example 3 0.06 1.31 0.07 1.31 1.11 Example 4 0.06 1.32 0.07 1.321 .12 Example 5 0.06 1.32 0.07 1.32 1.05 Example 6 0.06 1.33 0.07 1.33 1.06 Example 7 0.06 1.42 0.07 1.42 1.39 Example 8 0.05 1.46 0.06 1.46 1.31 Example 9 0.05 1.36 0.06 1.36 1.29 Example 10 0.06 1. 41 0.07 1.41 1.20 Comparative Example 1 0.06 1.36 0.07 1.22 0.68 Comparative Example 0.08 1.26 0.25 1.26 0.88 Comparative Example 3 0.08 1.25 0.22 1.25 0.88

Table 2 Results of quality performance test Moisture resistance 5) Plasticizer 6) Light resistance 7) Background image area Image area Background image area Example 1 0.07 1.33 1.26 △ △ Example 20 0.06 1.29 1.23 ○ △ Example 3 0.07 1.31 1.24 △ △ Example 4 0.07 1.32 1.25 △ △ Example 5 0.07 1.32 1.30 △ △ Example 6 0.07 1.33 1.30 △ △ Example 7 0.07 1.42 1.42 △ △ Example 8 0.06 1.46 1.43 △ △ Example 9 0.06 1.36 1.33 △ △ Example 10 0.07 1.41 1.38 △ △ Comparative Example 1 0.07 1.29 0.95 △ △ Comparative Example 2 0.20 1.23 1.20 × × × Comparative Example 3 0.15 1.23 1.18 × × ×

1) Background: A value (reflection density) obtained by measuring the uncolored portion of the sample with a Macbeth reflection densitometer RD-914 type. 2) Image Density A value obtained by measuring the density of a sample printed with a thermal printer (D-805P) manufactured by Ishida Koki Co., Ltd. using a Macbeth reflection densitometer RD-914 type. 3) Heat resistance The values obtained by leaving the unprinted area and the sample printed by the thermal test printer in a thermostat at 60 ° C. for 24 hours and measuring the respective densities with the Macbeth reflection densitometer. 4) Water resistance A value measured by the Macbeth reflection densitometer after immersing the sample printed by the thermal test printer in tap water at room temperature for 2 hours and air-drying. 5) Moisture resistance After leaving the unprinted part and the sample printed by the thermal test printer in a thermo-hygrostat at 40 ° C and a relative humidity of 90% for 24 hours, the respective densities were measured by the Macbeth reflection densitometer. . 6) Plasticizer resistance A sample printed with the above thermal test printer was sandwiched from both sides with a PVC wrap film and left at 25 ° C. for 24 hours under a load of 30 g / cm ² , and the printed part was measured with the above Macbeth reflection densitometer. value. 7) Light resistance After irradiating the unprinted part and the sample printed by the thermal test printer with a fluorescent lamp for 100 hours under an illumination of 10,000 lux, discoloration and fading of each sample were visually judged. ○ Marked with almost no discoloration or fading. △ Mark: Some discoloration or fading is observed. Marked by discoloration and fading.

[0110]

EFFECT OF THE INVENTION The heat-sensitive recording material of the present invention is heat- and moisture-resistant and has less background fog in unprinted areas and less reduction in color density of printed areas. Further, a heat-sensitive recording material which gives a colored image having good water resistance, plasticizer resistance and light resistance was obtained.

Claims (1)

[Claims] 1. A color-forming recording material comprising a colorless or light-colored electron-donating color-forming dye and an acidic substance, containing at least one epoxy resin represented by the formula (1). Thermosensitive recording material. General formula (1) (In the formula, R ₁ and R ₂ are the same or different and each represents a residue in which a hydroxyl group of a compound having two or more phenolic hydroxyl groups is removed. Z ₁ and Z ₂ are the same or different and are 0 or 1
The above integers are shown, and the sum of Z ₁ and Z ₂ is 1 or more.
Further, M is a glycidyl group or a hydrogen atom, and n is an integer of 1 or more. However, when n is 1, M is always a glycidyl group, and when n is 2 or more, at least one is a glycidyl group. )