JPS61146596A - Dichroic thermal recording material - Google Patents

Abstract

PURPOSE:To obtain a leuco-based dichroic thermal recording material capable of giving color pictures having good stability at high temperatures without color mixing, as well as having improved color separation property, by adding an achromatic agent for a low-temperature color-forming layer to an achromatic layer provided in a high-temperature color-forming layer or between the high- temperature color-forming layer and the low-temperature color-forming layer. CONSTITUTION:A high-temperature color-forming layer and a low-temperature color-forming layer are laminated in order on a supporter. The high-temperature color-forming layer contains a leuco dye capable of producing color at high temperatures and a thiourea derivative of the general formula (I), where R<1> is H, an alkyl, halogenated alkyl, acryl, or halogen, R<2> represents H or (II) (R<3> is H, alkyl, halogenated alkyl, acyl, or halogen), and Z is S or O and when Z is O, R<2> is H. The low-temperature color-forming layer contains a leuco dye capable of producing color at low temperatures and a phenolic compound. Also, an achromatic agent for the low-temperature color-forming layer is contained in the achromatic layer provided in high-temperature color-forming layer or between the high-temperature color-forming layer and the low- temperature color-forming layer to obtain a dichroic thermal recording material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a leuco two-color heat-sensitive recording material.

[Prior art 1 A thermosensitive recording material is a material in which a thermosensitive coloring layer that can form a colored image by heating is provided on a support such as paper, and a thermal printer equipped with a thermal head is widely used for heating. It is being

These conventional heat-sensitive recording materials include a colorless or light-colored leuco dye (color-forming main agent) having a lactone ring, lactam ring, spiropyran ring, etc. in the heat-sensitive coloring layer, and a developer that develops color by reacting with the leuco dye when heated. Coloring agent (R color auxiliary agent)
Those containing these are widely used because they have clear color tones and less fogging.

By the way, heat-sensitive recording materials can easily produce colored images just by heating them, so they are not only used for copying books, documents, etc., but are also used in various fields such as computer, facsimile, telex, and other fields for recording various types of information and measuring equipment. However, depending on the purpose of recording, in order to display particularly necessary data and numbers more clearly, the coloring of that part (
It goes without saying that it is desirable to be able to record with the display color (displayed color) different from the developed color of other parts.

Recently, attempts have been made to obtain multicolor recording by utilizing differences in heating temperature or thermal energy, and various multicolor thermosensitive recording papers have been proposed accordingly. Multi-color thermosensitive recording paper is generally formed by stacking two types of high-temperature and low-temperature coloring layers that develop different tones with different coloring heat energies on a support, and can be broadly classified into the following two types: Divided into types. One of them is that when coloring the high temperature coloring layer, the color is mixed with the color tone of the low temperature coloring layer to obtain a color tone different from that of the low temperature coloring layer.

The other method is to use a decoloring agent that decolorizes the low-temperature color-forming layer when coloring the high-temperature color-forming layer to obtain only the color tone of the high-temperature color-forming layer without color mixing of the color tone of the low-temperature color-forming layer. As a specific example of these, the former is
Publication No. 49-4342, Special Publication No. 49-2
7708, JP-A-48-86543, JP-A-49-65239, etc.;
7866, Japanese Patent Publication No. 51-29024, Japanese Patent Publication No. 51-87542, and Japanese Patent Publication No. 50-18048.

These are disclosed in Japanese Patent Laid-Open No. 53-47843 and the like.

However, in the case of the former multicolor thermosensitive recording paper,
During high-temperature color development, the color tone that can be specifically achieved is red-black because the color is mixed with the color tone of the low-temperature color development layer.

The drawback is that high-temperature color tones such as blue-black are limited to strong black threads. On the other hand, in the case of the latter multicolor thermosensitive recording paper, the combination of color tones can be freely selected, but when coloring at high temperatures, high aliphatic alcohols, polyethers, Polyethylene glycol derivatives, 7cetamide, stearamide, phthalonitrile, amine derivatives, guanidine derivatives, etc. as nitrogen-containing organic compounds have been proposed, but with conventional configurations, the coloring layer at a low temperature does not fade during high-temperature coloring. However, there were drawbacks such as the colored image being mixed with colors and becoming unclear, and also having a decoloring effect on the high-temperature coloring layer, making the colored image unclear. Furthermore, most two-color thermal papers have color tone combinations such as (blue-red) and (green-red), and no combinations such as (black-red) have been proposed.

〔the purpose〕

An object of the present invention is to provide a leuco-based two-color heat-sensitive recording material which has improved color separation properties, has no color mixture in high-temperature colored images, and has good stability in single-colored images.

〔composition〕

That is, according to the present invention, a high-temperature coloring layer and a low-temperature coloring layer are laminated in this order on a support, and the high-temperature coloring layer contains a high-temperature coloring leuco dye and a thiourea derivative represented by the following general formula. The low-temperature coloring layer contains a low-temperature coloring leuco dye and a phenolic compound, and the low-temperature coloring layer contains a low-temperature coloring layer or a decoloring layer provided between the high-temperature coloring layer and the low-temperature coloring layer. A two-color heat-sensitive recording material is provided, which is characterized in that it contains a layer decoloring agent.

General formula: (wherein R1 represents hydrogen, an alkyl group, a halogenated alkyl group, an acyl group, or a halogen; R2 represents hydrogen, a halogenated alkyl group, an acyl group, or a halogen), Z represents a sulfur or oxygen atom, (When Z is oxygen, R2 represents hydrogen) In the present invention, the low-temperature coloring layer decolorizing agent means a substance that exhibits decolorizing properties for the colored image of the low-temperature coloring layer, and such decolorizing agents include , conventionally known ones can be used.

In other words, the color erasing agents mentioned in the prior art erase the colored images of leuco dyes and phenolic compounds, but do not erase the colored images of high temperature chromogenic leuco dyes and thiourea derivatives. Therefore, in the present invention, when heated with low energy, the low-temperature coloring layer develops color, but when heated with high energy, the low-temperature coloring layer is decolored by the decoloring agent contained in the high-temperature coloring layer, and the high-temperature coloring layer develops color. By changing the applied energy, a clear two-color image can be obtained.

As the decolorizing agent for the low-temperature coloring layer in the present invention, the conventionally used decoloring agents described above are used, such as 1, for example, polyether, polyethylene glycol derivatives,
Examples include solid alcohols, aliphatic amines, aromatic amines, guanidine derivatives, etc., but in order to obtain products with good long-term storage stability, those with as low water solubility as possible are preferred.

It is usually sufficient to use such a decolorizing agent in an amount of 0.5 part by weight or more per 1 part by weight of the phenolic compound contained in the low-temperature coloring layer.

In the present invention, the low-temperature coloring layer decolorizing agent can be added to the high-temperature coloring layer so as to affect the low-temperature coloring layer, and can also be added to a decoloring layer between the low-temperature coloring layer and the high-temperature coloring layer. can be provided and contained in this decoloring layer.゛In this case, the low-temperature coloring layer is easily affected by the decoloring agent, so in order to keep the low-temperature coloring image clear, if the high-temperature coloring layer contains a decoloring agent, the high-temperature coloring layer and the low-temperature coloring layer must be Between the coloring layer or.

When a color erasing agent is contained in the color erasing layer, it is preferable to provide an intermediate layer between the low temperature coloring layer and the color erasing layer. Such an intermediate layer is preferably formed using a thermofusible substance having a melting point of 60° C. or higher. Specific examples of the thermofusible substance include various substances described below.

The thiourea derivative used as the color developer for the high-temperature color forming layer in the present invention is represented by the above general formula, and specific examples thereof include the following.

1,3-diphenylthiourea, ■, 3-di(P-methylphenyl)thiourea, 1,3-di(P-chlorophenyl)thiourea, 1,3-di(m-chlorophenyl)thiourea, 1, 3-di(0-methylphenyl)thiourea, 1゜3-di(■-methylphenyl)thiourea, 1,3-di(
〇-chlorophenyl)thiourea, 1,3-di(p-bromophenyl)thiourea, 1,3-di(m-bromophenyl)thiourea, 1,3-di(O-bromophenyl)thiourea, 1 .3-di(p-ethylphenyl)thiourea, 1
, 3-di(■-ethylphenyl)thiourea, 1,3-di(〇-ethylphenyl)thiourea, 1,3-di(p-isopropylphenyl)thiourea, 1,3-di(p-isobutyl phenyl)thiourea, 1,3-di(p-isoamylphenyl)thiourea, 1,3-di(octylphenyl)thiourea, 1,3-di(laarylphenyl)thiourea, 1,3-di( p-stearylphenyl)thiourea, 1
-Phenylthiourea, 1-(p-methylphenyl)thiourea, 1-phenylurea, 1-(p-chlorophenyl)
Thiourea, 1-(m-chlorophenyl)thiourea, 1.
3-di(w-trifluoromethylphenyl)thiourea,
1゜3-di(p-trifluoromethylphenyl)thiourea, 1.3-di(0-trifluoromethylphenyl)thiourea, 1,3-di(p-stearoylphenyl)thiourea, 1.3- Di(P-lauroylphenyl)thiourea and the like.

Further, examples of the phenolic compound used as a color developer for the low-temperature coloring layer in the present invention include the following.

gallic acid, salicylic acid, 3-isopropylsalicylic acid,
3-Cyclohexylsalicylic acid, 3,5-ter
t-Butylsalicylic acid, 3,5-di-α-methylbenzylsalicylic acid, 4,4'-isopropylidene diphenol, 4,4'-isopropylidene bis(2-chlorophenol), 4,4'-isopropylidene bis (2,6-
dibromophenol), 4,4'-isopropylidene bis(2,6-dichlorophenol), 4,4'-isopropylidene bis(2-methylphenol), 4,4'-
Isopropylidene bis(2,6-dimethylphenol)
, 4,4'-isopropylidene bis(2-tert-butylphenol), 4,4'-5ec-butylidene diphenol, 4,4'-cyclohexylidene bisphenol, 4,4'-cyclohexylidene bis(2- methylphenol), 4-tert-butylphenol,
4-phenylphenol, 4-hydroxydiphenoxide, α-naphthol, β-naphthol, 3,5-xylenol, thymol, methyl-4-hydroxybenzoate, 4-hydroxyacetophenone, novolac type phenolic resin, 2,2'-thiobis (4,6-dichlorophenol), catechol, resorcinol, hydroquinone,
Pyrogallol, phloroglycin, phloroglycin carboxylic acid, 4-tert-octylcatechol, 2,2'
-methylenebis(4-chlorophenol), 2,2'-
Methylenebis(4-methyl-6-tert-butylphenol), 2,2'-dihydroxydiphenyl, p-
Ethyl hydroxybenzoate, propyl P-hydroxybenzoate, butyl P-hydroxybenzoate, benzyl P-hydroxybenzoate, p-chlorobenzyl p-hydroxybenzoate, 〇-chlorobenzyl P-hydroxybenzoate, p- p-methylbenzyl hydroxybenzoate, ρ-octyl hydroxybenzoate, benzoic acid,
Zinc salicylate, 1-hydroxy-2-naphthoic acid, 2
-hydroxy-6-naphthoic acid, 2-hydroxy-6-
Zinc naphthoate, 4-hydroxydiphenylsulfone,
4-hydroxy-4'-chlorodiphenyl sulfone, bis(4-hydroxyphenyl) sulfide, etc.

The leuco dyes used in the present invention can be applied singly or in combination of two or more types, but such leuco dyes include:
Any of those applied to this type of heat-sensitive material may be used. For example, leuco compounds of dyes such as triphenylmethane-based, fluoran-based, phenothiazine-based, auramine-based, and spiropyran-based dyes are preferably used. Specific examples of such leuco dyes include those shown below.

3.3-bis(p-dimethylaminophenyl)-phthalide, 3.3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide (also known as crystal violet lactone), 3.3-bis(p- dimethylaminophenyl)-6-dibutylaminophenyl.

3.3-Bis(P-dimethylaminophenyl)-6-chlorphthalide.

3.3-bis(p-dibutylaminophenyldo, 3-cyclohexylamino-6-chlorofluorane 3-
Dimethylamino-5,7-dimethylfluorane, 3-diethylamino-7-chlorofluorane.

3-diethylamino-7-methylfluorane, 3-diethylamino-7,8-benzfluorane.

3-diethylamino-6-methyl-7-chlorofluorane.

3-(N-p-hly-N-ethylamino)-6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 2-(N-(3'- trifluoromethylphenyl)amino)-6-dinithylaminofluorane, 2-(3
．． 6-bis(diethylamino)-9-(o-chloroanilino)xantylbenzoic acid lactam), 3-diethylamino-6-methyl-7-(m-trichloromethylanilino)fluoran, 3-diethylamino-7-(O-chloroanilino) Fluoran, 3-dibutylamino-7-(0-chloroanilino)fluoran, 3-=N-methyl-N-amylamino-6-methyl-7
-anilinofluorane, 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-(N,N- diethylamino)-5-methyl-7-(
N.

N-dibenzylamino)fluoran, benzoylleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-pyrylospirane, 6'-bromo-3'-methoxy-benzoindolino-pyrylospirane.

3-(2'-hydroxy-41-dimethylaminophenyl)-3-(2'-methoxy-5'-chlorophenyl)phthalide, 3-(2'-hydroxy-4'-dimethylaminophenyl)-3- (2'-methoxy-5'-nitrophenyl)phthalide, 3-(2'-hydroxy-4'-diethylaminophenyl)-3-(2'-methoxy-5'-methylphenyl)phthalide, 3-(2 '-methoxy-4'-dimethylaminophenyl)-3-(2'-hydroxy-4'-chloro-5
1-methylphenyl)phthalide.

3-morpholino-7-(N-propyl-trifluoromethylanilino)fluorane, 3-pyrrolidino-7-trifluoromethylanilinofluorane, 3-diethylamino-5-chloro-7-(N-benzyl-trifluoro methylanilino)fluoran, 3-pyrrolidino-7-(di-p-chlorophenyl)methylaminofluoran, 3-diethylamino-5-chloro-7-(α-phenylethylamino)fluoran.

3-(N-ethyl-p-toluidino)-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-(o-methoxycarbonylphenylamino)fluoran, 3-diethylamino-5-methyl-7-( α-phenylethylamino)fluorane, 3-diethylamino-7-piperidinofluorane, 2-
Chloro-3-(N-methyltoluidino)-7-(p-n
-butylanilino)fluoran, 3-(N-benzyl-N-cyclohexylamino)-5
, 6-penzo 7-α-naphthylamino-4'-bromofluorane, 3-diethylamino-6-methyl-7-mesitidino 4
', 5'-benzofluorane, etc.

In the present invention, two types of leuco dyes having different melting points are combined, and the one with a lower melting point is used as a low-temperature color-forming leuco dye, and the one with a higher melting point is used as a high-temperature color-forming leuco dye. Specific examples of particularly preferable leuco dyes to be included in the high-temperature coloring layer include 3-diethylamino-7-lyrofluorane and 3-diethylamino-7-lyrofluorane.
Examples include 6-methyl-7-chlorofluoran, 3-cyclohexylamino-6-chlorofluoran, and 3-diethylaminobenzo[α]fluoran.

In the present invention, in order to bond and support each layer on the support, various conventional binders can be used as appropriate. Examples include polyvinyl alcohol, starch and its derivatives, and methoxycellulose.

Cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, and ethyl cellulose, and sodium polyacrylate.

Polyvinylpyrrolidone, acrylic amide/acrylic ester copolymer, acrylic amide/acrylic ester/methacrylic acid ternary copolymer, styrene/maleic anhydride copolymer alkali salt, isobutylene/maleic anhydride copolymer alkali In addition to water-soluble polymers such as salt, polyacrylamide, sodium alginate, gelatin, and casein, polyvinyl acetate, polyurethane, styrene/butadiene copolymer, polyacrylic acid, polyacrylic acid ester, vinyl chloride/vinyl acetate copolymer , polybutyl methacrylate, ethylene/vinyl acetate copolymer, styrene/
Latexes such as butadiene/acrylic copolymers can be used.

In addition, in the present invention, in addition to the leuco dye and color developer, auxiliary additive components commonly used in this type of heat-sensitive recording material, such as fillers, surfactants, thermofusible substances, etc. (or lubricant) etc. can be used in combination. In this case, fillers include, for example, calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, and surface-treated inorganic fine powders such as calcium and silica. , urea-formalin resin, styrene/methacrylic acid copolymer, polystyrene resin, and other organic fine powders. Examples of thermofusible substances include higher fatty acids or their esters, amides, or metal salts. In addition, various waxes, condensates of aromatic carboxylic acids and amines, benzoic acid phenyl esters, higher linear glycols, dialkyl 3,4-epoxy-hexahydrophthalates, higher ketones, and other thermofusible organics. Examples include compounds having a melting point of about 60 to 200°C.

〔effect〕

The two-color thermosensitive recording material of the present invention has the above-mentioned structure, and when coloring is performed at a high temperature, the decoloring agent acts on the coloring reaction system of the low-temperature coloring layer to decolor the low-temperature coloring image, but does not affect the high-temperature coloring layer. not give. Therefore, the two-color image formed from the heat-sensitive recording material of the present invention has good color separation, and provides a clear and stable low-temperature color image and high-temperature color image.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples. Note that all parts and percentages shown below are based on weight.

Examples 1 to 3 The following components were each pulverized and dispersed for 72 hours using a ball mill to obtain dispersions A, B, C, and D.

E and F were prepared.

[Dispersion liquid-A]

20 parts of 3-diethylamino-7-chlorofluorane 10% itaconic acid-modified polyvinyl alcohol alkali salt
Aqueous solution 20 parts water
6o parts [Dispersion-F] 1.3-di(m-chlorophenyl)thiourea 20 parts Calcium carbonate 20 parts Itaconic acid modified polyvinyl alcohol alkali salt 10% aqueous solution 20 parts Water
40 parts [dispersion liquid-
C] Thermofusible substances shown in Table 1 20 parts Calcium carbonate 20 parts lO% methylcellulose aqueous solution 20 parts Water
40 parts [Dispersion-F] 1.3-dicyclohexyl-2-phenylguanidine
20 parts Calcium carbonate 20 parts Itaconic acid modified polyvinyl alcohol alkali salt 10% aqueous solution
20 parts water
40 parts [Dispersion-F] 3-di(n-butyl)amino-7-〇-chlorofluorane 20 parts Itaconic acid-modified polyvinyl alcohol alkali salt 1O% aqueous solution
20 parts water
60 parts [Dispersion-F] Benzyl roseate hydroxybenzoate 20 parts Calcium carbonate 20 parts Itaconic acid modified polyvinyl alcohol alkali salt 10% aqueous solution
20 parts water
20 parts or more of Dispersion A 10 parts, Dispersion 840 parts, Dispersion D 40 parts
The mixture was mixed and stirred to obtain a high-temperature coloring layer forming solution. Next, part of the dispersion F1O and part of the dispersion F2O were mixed and stirred to obtain a low-temperature coloring layer forming liquid.

The high-temperature color forming layer forming liquid, intermediate layer forming decolorizing agent liquid (dispersion C), and low-temperature color forming layer forming liquid prepared as described above were mixed with a basis weight of 50.
g/rrl' of commercially available high-quality paper, the high temperature layer, intermediate layer, and low temperature layer each have a dry weight of 6 g/rrr.

Sequentially coated and dried to 2g/rrr and 3g/rf,
A two-color heat-sensitive recording material of the present invention was obtained.

Example 4 A two-color heat-sensitive recording material was obtained in the same manner as in Example 1 except that the intermediate layer was omitted.

The above heat-sensitive recording sheets were tested for their dynamic color tone and image fading resistance. The results are shown in Table-1. The test method was performed as follows.

Dynamic color tone test: Using a thermal printing experimental device with a thin film head manufactured by Kenshi Electronics Co., Ltd., head power 0.6 W/dot, 1 line recording time 20i+s/n, scanning line density 8 x 3.85 dots/mm. Pulse width under the conditions of 1, 2n+s during low temperature color development
Print at 2.4was at high temperature and check the color tone.

Image fading property: The image density of the low-temperature color image in the dynamic color tone test was measured using a Macbeth densitometer RD514 (filter 1tl1) and the image density immediately after printing (Do) and the image density (D) of 1 square.
06), and the image fading property is evaluated by the density reduction rate expressed by the following formula.

Table 1 As can be seen from the results shown in Table 1, in the case of the present invention, a black color develops at a low temperature, and when a high temperature color develops, the black color disappears and a clear vermilion color develops, and the applied energy is changed. By using an intermediate layer, you can obtain two colors that are more vivid.
It can be seen that the stability of the colored image is significantly improved.

Examples 5 to 7 Among the dispersions A to F shown in Example 1, 10 parts of dispersion A and 20 parts of dispersion B were mixed and stirred to obtain a high-temperature coloring layer forming liquid. Next, a portion of the dispersion EIO and a portion of the dispersion F2O were mixed and stirred to obtain a low temperature coloring layer forming liquid.

The high-temperature color forming layer forming liquid, the decoloring agent layer forming liquid (dispersion D), the intermediate layer forming liquid (dispersion C), and the low-temperature color forming layer forming liquid prepared as above were mixed with commercially available liquids with a basis weight of 50 g#rF. The dry weight of the high temperature layer, decoloring layer, middle layer, and low temperature layer on high-quality paper is 4g/-14g/n, respectively? The two-color heat-sensitive recording material of the present invention was obtained by sequentially coating and drying the coating to give a coating density of 2 g/l and 3 g/-.

The above heat-sensitive recording sheet was subjected to a dynamic color tone test and an image fading test. The results are shown in Table-2. .

Table 2 Examples 8 to 12 Using a ball mill, each of the following ingredients was
Time-pulverized and dispersed, each dispersion A, B, C, D.

E was prepared.

[Dispersion liquid-A]

20 parts of 3-diethylamino-7-chlorofluorane 10% itaconic acid-modified polyvinyl alcohol alkali salt
Aqueous solution 20 parts water
60 parts [Dispersion-B] High temperature layer color developer shown in Table 3 20 parts Calcium carbonate 20 parts Itaconic acid modified polyvinyl alcohol alkali salt 10% aqueous solution
20 parts water
40 parts [Dispersion -〇] Decolorizing agent shown in Table 3 20 parts Itaconic acid modified polyvinyl alcohol alkali salt 10% aqueous solution 20 parts Water
2o parts (dispersion liquid-
〇〇 3-di(n-butyl)amino-7-o-chloroanilinofluorane 20 parts Itaconic acid-modified polyvinyl alcohol alkali salt 10% aqueous solution
20 parts water
20 parts [Dispersion-B
] Low-temperature layer color developer shown in Table 3 20 parts Itaconic acid-modified polyvinyl alcohol alkali salt 10% aqueous solution 20 parts Calcium carbonate
20 parts water
20 parts or more of dispersion-A prepared as above, 10 parts of dispersion-840 parts, dispersion-C
40 parts were mixed and stirred to obtain a high temperature color forming layer forming liquid.

Next, parts of the dispersion DIO and 40 parts of the dispersion E were mixed and stirred to obtain a low temperature coloring layer forming liquid.

The high-temperature coloring layer and low-temperature coloring layer liquid prepared as described above were placed on commercially available high-quality paper with a basis weight of 50 g/nf.

The weight of the high-temperature coloring layer and the low-temperature coloring layer after drying is 6.
Apply 0g/rd and 3.0g/% and dry.
A two-color heat-sensitive recording material of the present invention was obtained.

Comparative Examples 1 and 2 A comparative two-color thermosensitive recording material was obtained in the same manner as in Example 8, except that the developer for the high-temperature coloring layer of Dispersion-8 of Example 8 was changed to a phenol compound.

The above heat-sensitive recording materials were tested for dynamic color tone. The results are shown in Table-3.

Claims (2)

[Claims] (1) A high-temperature color-forming layer and a low-temperature color-forming layer are laminated in this order on a support, and the high-temperature coloring layer contains a high-temperature color-forming leuco dye and a thiourea derivative represented by the following general formula; The low temperature color forming layer contains a low temperature color forming leuco dye and a phenolic compound, and a low temperature color forming layer decoloring agent is provided in the high temperature color forming layer or in the decoloring layer provided between the high temperature color forming layer and the low temperature color forming layer. A two-color heat-sensitive recording material characterized by containing: General formula: ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R^1 is hydrogen, alkyl group, halogenated alkyl group, acyl group, or halogen, R^2 is hydrogen, or ▲ Numerical formulas, chemical formulas, tables, etc. There is ▼ (in the formula, R^3 is hydrogen,
(represents an alkyl group, a halogenated alkyl group, an acyl group, or a halogen), Z represents a sulfur or oxygen atom, and when Z is oxygen, R^2 represents hydrogen) (2) Between the high temperature coloring layer and the low temperature coloring layer, or if a color erasing layer is provided, between the color erasing layer and the low temperature coloring layer, the melting point 60
A two-color heat-sensitive recording material according to claim 1, further comprising an intermediate layer containing a thermofusible substance having a temperature of 0.degree. C. or higher.