JPS631589A - Two color thermal recording material - Google Patents

Abstract

PURPOSE:To obtain the clear high temperature coloring picture of a high coloring density and besides, to achieve the improvement of the shelf life in terms of heat resistance, humidity resistance, etc., by using a specific compound as the developer for a high temperature coloring layer. CONSTITUTION:A high temperature coloring layer, a decoloring layer, and a low temperature coloring layer are laminated in that order on a base material. Then, the compound A expressed by a formula 1 and the compound B expressed by a formula II or a formula III are used as the developer of the high temperature coloring layer. When the compound expressed by this formula 1 is used as the developer of the high temperature coloring layer, the coloration due to texture fogging, finger marks, etc. in the storage for a long time does not occur. Further, when the compound expressed by the formula II or III is contained as the developer, a sufficient clear picture can be obtained by preventing decoloring agent from acting the high temperature coloring layer when a two-color picture is formed. In the formula, Z represents -S- or the like and R1-R6 represent H or the alkyl group of 1-4 in carbon number.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a two-color heat-sensitive recording material, and more specifically, the present invention relates to a two-color heat-sensitive recording material, and more specifically, a leuco dye that is usually colorless or slightly pale in color, and a color developer that reacts with the leuco dye when heated to develop a color. It relates to a two-color heat-sensitive recording material formed by laminating heat-sensitive coloring layers containing as a main component.

[Prior art]

A thermosensitive recording material is a material in which a thermosensitive coloring layer capable of forming 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.

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 color developer that develops color by reacting with this leuco dye when heated. Agent (color development aid)
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 roughly divided into the following types: It is divided into two types. One is to mix the color with the color tone of the low temperature coloring layer when coloring the high temperature coloring layer to obtain a color tone different from the coloring tone of the low temperature coloring layer, and the other is to color the high temperature coloring layer. In this case, by using a decoloring agent that decolorizes the low-temperature color-forming layer, only the color tone of the high-temperature color-forming layer is obtained without color mixture of the color tone of the low-temperature color-forming layer. As specific examples of these, the former are disclosed in Japanese Patent Publication No. 49-69, Japanese Patent Publication No. 49-4342, Japanese Patent Publication No. 49'-27708, Japanese Patent Application Publication No. 86543-1986, and Japanese Patent Publication No. 49-65.
239, etc., and the latter is described in Japanese Patent Publication No. 50-17865, Japanese Patent Publication No. 17866, Japanese Patent Publication No. 51-29024, Japanese Patent Publication No. 51-87.
These are disclosed in Japanese Patent Application Laid-Open No. 542, Japanese Patent Application Laid-Open No. 18048-1982, Japanese Patent Publication No. 36519-1987, and the like.

However, in the case of the former multicolor thermosensitive recording paper,
During high-temperature coloring, the color tone is specifically realized to mix with the color tone of the low-temperature coloring layer, and the disadvantage is that the high-temperature coloring tone is limited to black threads with strong strength, such as red-black, blue-black, etc. There is. - On the other hand, in the case of the latter multicolor thermosensitive recording paper, the combination of one color tone can be freely selected, but when high temperature coloring is performed, higher aliphatic alcohols, polyethers, etc. , polyethylene glycol derivative,
Acetamide, stearamide, phthalonitrile as a nitrogen-containing organic compound, a guanidine derivative, a morpholine derivative, etc. as an amine derivative are used. but,
Such multicolor recording materials have the drawback that during image formation, high-temperature colored images cause color mixture, are easily erased by a color erasing agent, and become unclear.

〔the purpose〕

An object of the present invention is to provide a two-color heat-sensitive recording material that can obtain high-density, high-temperature colored images, has excellent storage stability such as heat resistance and moisture resistance, and has little background fog.

〔composition〕

According to the present invention, in a two-color thermosensitive recording material in which a high-temperature coloring layer, a decoloring layer, and a low-temperature coloring layer are laminated in that order on a support,
A two-color heat-sensitive recording material characterized in that a compound represented by the following general formula (A) and a compound represented by the following general formula (B) or general formula (C) are used as a color developer in the high-temperature coloring layer. is provided.

R2, R3 and R4 each represent 11 or an alkyl group having 1 to 4 carbon atoms. ) (wherein R1, R2, R3, R4, RS and 11. are 1
1 or an alkyl group having 1 to 4 carbon atoms. ) (In the formula, Y represents an alkylene group having 1 to 4 carbon atoms, -8- or -302-, and X represents a halogen.) Conventionally, as a color developer for a high temperature coloring layer of a two-color thermosensitive recording material, Phenol derivatives, p-benzylbenzoic acid ester derivatives, thiourea derivatives, etc. have been proposed, but those containing these color developers in high-temperature coloring layers do not work well under high-temperature or high-humidity environments for long periods of time. When stored, there are problems with storage, such as background fogging and color development due to fingerprints, etc.Furthermore, when a two-color image is formed, the decoloring agent also acts on the high-temperature color layer, resulting in a clear high-temperature color image. The drawback was that it was not available.

Regarding this point, the present inventors have previously found that when the compound represented by the general formula (A) is used as a color developer in a high-temperature coloring layer, no coloring occurs due to background fogging or fingerprints during long-term storage. However, it has been found that even in this case, there is a problem in that during two-color image formation, the decoloring agent also acts on the high-temperature color forming layer, making it impossible to obtain a sufficiently clear image.

In order to improve this point, the present inventors conducted extensive research and found that the high-temperature coloring layer contains a compound represented by the general formula (A) and a compound represented by the general formula (B), or a compound represented by the general formula (A).
) and the compound represented by the general formula (C) as color developers, it was discovered that these drawbacks could be overcome, and the present invention was completed. It is.

Specific examples of the compound represented by the general formula (A) used in the present invention include the following.

Examples of the compound represented by the general formula (B) used in the present invention include those shown below.

4.4'-isopropylidene-bis-phenol, 4
．． 4'-butylidene-bis-(3-methyl-6-tert-butylphenol), 4.4'-methylene-bis-(2,6-di-tert-butylphenol), 4.4'-di-hydroxy-diphenylmethane , polybutylated bis-phenol A, etc.

Moreover, examples of the compound represented by the general formula (C) used in the present invention include those shown below.

In addition, in the present invention, in order to obtain a two-color heat-sensitive recording material with excellent heat resistance and moisture resistance as well as a clear high-temperature coloring image, in the high-temperature coloring layer, per 1 part by weight of the leuco dye used in the high-temperature coloring layer, It is preferable that the total amount of the color developer represented by the general formula (A) and the general formula (B) or the general formula (C) is 6 parts by weight or more.

If it is less than this, the effect of the decolorizing effect of the decolorizing agent becomes noticeable when forming a high-temperature color image, making it impossible to obtain a clear high-temperature color image, and reducing heat resistance, moisture resistance, etc., and causing background fogging. etc. will occur.

In the present invention, examples of the color developer contained in the low-temperature coloring layer include N,N'-diphenylthiourea, N-p-
Ethylphenyl-N'-phenylthiourea, N-p-butylphenyl-N'-phenylthiourea, N,N'-di-m-chlorophenylthiourea, N,N'-di-P-chlorophenylthiourea, N,N '-G m-h Rifluoromethylphenylthiourea.

N, N', -di-m-methylphenylthiourea, 4,
4'-inpropylidene 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-tert-butylphenol), 4.
4'-5ec-butylidene diphenol, 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, novolak type phenolic resin, 2,
2'-thiobis(4,6-dichlorophenol), catechol, resorcinol, hydroquinone, pyroganol,
Phloroglucin, phloroglycin carboxylic acid, 4-t
ert-octylcatechol, 2,2'-methylenebis(4-chlorophenol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol),
2,2'-dihydroxydiphenyl, ethyl ρ-hydroxybenzoate, propyl P-hydroxybenzoate, P-
Butyl hydroxybenzoate, benzyl p-hydroxybenzoate, p-chlorobenzyl p-hydroxybenzoate, 〇-chlorobenzyl p-hydroxybenzoate, p-
p-methylbenzyl hydroxybenzoate, n-octylbenzoic acid ρ-hydroxybenzoate, zinc salicylate, ■-hydroxy-2-naphthoic acid, 2-hydroxy-
6-naphthoic acid, zinc 2-hydroxy-6-naphthoate, 4-hydroxydiphenylsulfone, 4-hydroxy-4'-chlorodiphenylsulfone, bis(4-hydroxyphenyl)sulfide, etc. are used.

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:
Those applied to this type of heat-sensitive material can be arbitrarily applied, and for example, leuco compounds of dyes such as triphenylmethane-based, fluoran-based, phenothiazine-based, auramine-based, spiropyran-based, and indolinophthalide-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-chlorophthalide, 3.3-bis(P-dibutylaminophenyl) phthalide.

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-tolyl-N-ditylamino)-6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 2- (N-(3'-trifluoromethylphenyl)
amino)-6-dinithylaminofluorane.

2-(3,6-bis(diethylamino)-9-(o-
chloranilino)xantylbenzoic acid lactam), 3-
Diethylamino-6-methyl-7-(+-trichloromethylanilino)fluoran, 3-diethylamino-7-(o-chloroanilino)fluoran, 3-dibutylamino-7-(o-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)fluorane.

Benzoylleucomethylene blue.

6'-chloro-8',-methoxy-benzoindolino-
Pyrylospiran, 6'-bromo-3'-methoxy-benzoindolino-pyrylospiran, 3-(2'-hydroxy-4'-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'
-methylphenyl)phthalide.

3-morpholino-7-(N-propyl-trifluoromethylanilino)fluorane.

3-pyrrolidino-7-trifluoromethylanilinofluorane, 3-diethylamino-5-chloro-7-(N-benzyl-trifluoromethylanilino)fluorane.

3-pyrrolidino-7-(di-ρ-chlorophenyl)methylaminofluorane, 3-diethylamino-5-chloro-7-(α-)enylethylamino)fluoran.

3-(N-ethyl-p-toluidino)-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-(0-methoxycarbonylphenylamino)fluoran, 3-diethylamino-5-methyl-7-( α-phenylethylamino)fluorane.

3-diethylamino-7-piperidinofluorane.

2-chloro-3-(N-methyltoluidino)-7-(p
-n-butylanilino)fluorane, 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, specific examples of particularly preferable leuco dyes to be contained in the high temperature coloring layer include 3-diethylamino-7-chlorofluoran, 3-diethylamino-6-methyl-7-chlorofluoran, and 3-cyclofluoran. Examples include hexylamino-6-chlorofluorane, 3-diethylaminobenzo[α]fluorane, and the like.

As the color erasing agent used in the present invention, various conventionally known color erasing agents such as those shown in the explanation of the prior art can be used. Formula (1), (II), (II
Compounds represented by I), (fV) and (V), or compounds having three or more amide groups in the molecule, or two or more amide groups and one or more tertiary amino groups, N
, N'-dithiocaprolactam and the like are advantageously used.

General formula (1) General formula (II) General formula (!■) F] R, -Co-N　N-Co-R.

General formula (r/) General formula (V) In the above general formulas (1), (II) and (Ill), R4 and R2 are alkyl, cycloalkyl, aryl or aralkyl which may have a substituent. and X is carbonyl or sulfonyl. The alkyl represented by R and R2 is usually a straight chain or branched chain having 1 to 18 carbon atoms, and the cycloalkyl is
Examples of aryl include phenyl, tolyl, xylyl, and the like; examples of aralkyl include benzyl, phenethyl, and the like. These substituents can further have other substituents, such as alkyl, aryl,
In addition to halogen, alkoxy and aryloxy.

Examples include acyl, acyloxy, alkoxycarbonyl, carbamoyl, and acylamino. Also,
Also in the piperazine ring in general formulas (1) to (III),
One or two substituents such as alkyl, aryl, halogen, alkoxy, aryloxy, acyl, acyloxy, alkoxycarbonyl, carbamoyl, acylamino, etc.
More than one may be combined.

Specific examples of the compound represented by the general formula ([) include the following.

N-methyl-N'-phenylacetylpiperazine, N-
Propyl-N'-phenylacetylpiperazine.

N-propyl-N'-benzoylpiperazine, N-butyl-N'-benzoylpiperazine, N-cyclohexyl-N'-benzoylpiperazine, N-hexyl-N'-benzoylpiperazine, N-lauryl-N'-benzoylpiperazine , N-stearyl-
N'-benzoylpiperazine, N-phenyl-N'-benzoylpiperazine, N-benzyl-N'-benzoylpiperazine, N-phenyl-N'-cyclohexyloylpiperazine, N-phenyl-N'-acetylpiperazine, N- Phenyl-N'-lauroylpiperazine, etc.

Specific examples of the compound represented by the general formula (n) include the following.

N,N'-bis(benzenesulfonyl)piperazine,
N,N'-bis(p-methylbenzenesulfonyl)piperazine.

N,N'-bis(P-isopropylbenzenesulfonyl)piperazine, N,N'-bis(ρ-chlorobenzenesulfonyl)piperazine, N,N'-bis(0-chlorobenzenesulfonyl)piperazine.

N,N'-bis(m-chlorobenzenesulfonyl)piperazine.

N,N'-bis(p-bromobenzenesulfonyl)piperazine, N,N'-bis(butylsulfonyl)piperazine, N
, N'-bis(octylsulfonyl)piperazine, N
, N'-bis(laurylsulfonyl)piperazine.

N,N'-bis(stearylsulfonyl)piperazine, N,N'-bis(cyclohexylsulfonyl)piperazine.

N,N'-bis(p-laurylbenzenesulfonyl)
piperazine, N,N'-bis(cyclohexylsulfonyl)piperazine, and the like.

Specific examples of the compound represented by the general formula (11) include the following.

N,N'-bis(butyroyl)piperazine, N,N'
-bis(hexyloyl)piperazine, N,N'-bis(n-ofthyroyl)piperazine, N,N'-bis(tertiary-ofthyroyl)piperazine, N,N'-bis(lauriloyl)piperazine, N,N
' -Bis(stearoyl)piperazine, N, N' -
Bis(pivaloyl)piperazine.

NHN'-bis(cyclohexyloyl)piperazine.

N,N'-bis(P-methylcyclohexyloyl)piperazine, N,N'-bis(P-methylphenylacetyl)piperazine, N,N'-bis(phenylacetyl)piperazine, N
, N'-bis(phenylpropionyl)piperazine.

NUN' -bis(benzoyl)piperazinone, N,N
'-bis(phenoxyacetyl)piperazine, N,N
'-bis(p-chlorobenzoyl)piperazine, N,
N'-bis(2-phenoxypropionyl)piperazine and the like.

In the general formula (IV), R□, R,, R1 and R4 represent substituted or unsubstituted alkyl, cycloalkyl, aryl or aralkyl, and R1 and R2 or R1 and R4 are bonded at their terminal ends, respectively. It is also possible to form a ring. The alkyl usually includes a straight chain or branched chain having 4 to 18 carbon atoms, the cycloalkyl includes cyclohexyl, the aryl includes phenyl, tolyl, xylyl, etc. Examples of alkyl include benzyl and phenethyl. These substituents can further have other substituents,
Examples of such substituents include alkyl and aryl.

In addition to alkoxy, acyl, halogen, etc., acylamino such as benzoylamino and acetylamino, alkoxycarbonyl, carbamoyl, aryloxy, aralkyloxy, etc. can be mentioned. A is a fatty acid group or an aromatic group; in the case of an aliphatic group, it is usually substituted or unsubstituted alkylene having 1 to 8 carbon atoms; in the case of an aromatic group, it is substituted or unsubstituted phenylene, tolylene, xylylene. etc., and in this case, the substituents include the above-mentioned halogen, acylamino, alkoxycarbonyl,
Examples include carbamoyl, aryloxy, aralkyloxy and the like.

Specific examples of the disubstituted amide compounds of aliphatic and aromatic dicarboxylic acids include the following.

N, N, N'N'-tetrabutylsuccinic acid diamide, N
, N, N'N' -Tetraoctylsuccinic diamide, N, N, N'N' - Tetralaurylsuccinic diamide, N, N, N'N' - Tetrastearylsuccinic diamide, N, N, N'N'-tetraphenyladipic acid diamide, N+NIN'N'-tetra-ρ
-Butylphenyladipic acid diamide.

N,N,N'N'-tetrabutyladipate diamide, N,N,N'N'-tetraoctyladipate diamide, N,N,N'N'-tetralauryladipate diamide, N,N,N 'N'-tetrastearyladipate diamide, N,N'-dicyclohexyl-N,N'-dimethylsuccinic acid diamide.

N,N'-isophthaloyl bispyrrolidine, N,N'
-phthaloylbis-diethylamine, N,N'-terephthaloylbis-diethylamine, N,N'-isophthaloylbis-diethylamine, N,N'-phthaloylbis-diethylamine, N,N'-terephthaloylbis-diethylamine Propylamine.

N,N'-isophthaloylbis-dipropylamine,
N, N'-terephthaloylbis-dibutylamine, N
, N'-isophthaloylbis-dibutylamine, N,
N'-terephthaloylbis-cyclohexyl-methylamine, N,N'-isophthaloylbiscyclohexyl-methylamine, N,N'-terephthaloylbis-dicyclohexyl-
Amine, N,N'-isophthaloylbis-dicyclohexyl-
Amin et al.

In the general formula (V), Ro and R2 represent alkyl, cycloalkyl, aryl, or aralkyl which may have a substituent. Examples of the alkyl include straight-chain or branched chains having 1 to 18 carbon atoms, examples of the cycloalkyl include cyclohexyl, examples of the aryl include phenyl, tolyl, xylyl, etc. Examples of alkyl include benzyl and phenethyl.

These substituents can further have other substituents, such as alkyl, aryl, halogen, alkoxy, aryloxy, aralkyloxy, acyl, acyloxy, alkoxycarbonyl, carbamoyl, Examples include substituents such as acylamino. Yl and Y2 are linear or branched carbon atoms of 1 to 18
is an alkylene group.

Specific examples of such compounds include the following.

N,N'-bis(benzoylaminoethyl)piperazine, N,N'-bis(benzoylaminopropyl)piperazine, N,N'-bis(benzoylaminobutyl)piperazine.

N,N'-bis(cyclohexylaminopropyl)piperazine, N,N'-bis(hexylaminopropyl)piperazine, N-benzoylaminopropyl-N'-cyclohexylaminoethylpiperazine, N-benzoylamino Propyl-N'-benzoylaminobutylpiperazine.

N-(P-chlorobenzoylaminoamino)-N'-benzoylaminopropylpiperazine, N-cyclohexylaminopropyl-N'-cyclohexyloylaminobutylpiperazine, and the like.

Further, specific examples of the compound having three or more amino groups, two or more amide groups, and one or more tertiary amino groups in the molecule include, for example, the following.

N, N', N"-tribenzoyl-diethylenetriamine, N, N'N'-tribenzoyl-dipropylene triamine, N IN'jN' IN-tetrabenzoyl-triethylenetetramine, 1,7-dibenzoyl-4-methyl -diethylenetriamine, 1.9-dibenzoyl-5-methyl-dipropylenetriamine, 1.7-diα-naphthoyl-4-methyl-diethyltriamine, 1.7-diα-naphthoyl-4-cyclohexyl-diethylenetriamine, N, N', N'-tripivaloyl-diethylenetriamine, N, N', N', N-tetraacetyl-triethylenetetramine, N, N', N", N-tetracyclohexyloyl-triethylenetetramine, etc.

In the present invention, in order to bind and support the leuco dye, color developer and decolorizer on the support, various conventional binders can be used as appropriate. For example, polyvinyl alcohol, starch and its derivatives, methoxycellulose,
Cellulose derivatives such as hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, and ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylamide/acrylic acid ester copolymer, acrylamide/acrylic acid ester/methacrylic acid ternary copolymer, styrene Water-soluble polymers such as / maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, casein, polyvinyl acetate, polyurethane, styrene/butadiene copolymer Coalescence, polyacrylic acid, polyacrylic ester, vinyl chloride/vinyl acetate copolymer, polybutyl methacrylate.

Latex such as ethylene/vinyl acetate copolymer, styrene/butadiene/acrylic copolymer, etc. 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 and surfactants, may be used in combination, if necessary. . In this case, fillers include, for example, calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, tar, and surface-treated inorganic fine powders such as calcium and silica. Other examples include organic fine powders such as urea-polymarine resin, styrene/methacrylic acid copolymer, and polystyrene resin. Further, if necessary, a thermofusible substance commonly used in this type of field can be used for the low-temperature coloring layer. In this case, examples of the thermofusible substance include higher fatty acids or their esters, amides, In addition to metal salts, - various waxes, condensates of aromatic carboxylic acids and amines, phenyl benzoate, higher linear glycols, dialkyl 3,4-epoxy-hexahydrophthalates, higher ketones, and other heat Examples include those having a melting point of about 50 to 200°C, such as fusible organic compounds.

Further, in the present invention, a protective layer may be provided on the low-temperature coloring layer in order to improve matching properties (head dregs, sticking, etc.) with the thermal head.

〔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.

Example 1 Each of the following ingredients was prepared using a sand mill to give an average particle size of 2 to 2.
The powder was pulverized and dispersed to a particle size of 3 μm to prepare dispersions A to E.

[Dispersion liquid-A]

3-(N-ethyl-N-amylamino)-6-methyl-
7-anirithufluoran (black) 20 parts 10% hydroxyethyl cellulose aqueous solution 2Qn water
601I [Dispersion-B] 3.3-Dichlorophenylthiourea 10 parts Calcium carbonate 10II Polyvinyl alcohol (1 inch water m liquid) 2011 water
6
0II [Dispersion-B] 3-diethylamino-7-chlorofluorane 20 parts Polyvinyl alcohol (10% aqueous solution) 201/
water
60〃[Dispersion-B] 4.4'-cyclohexylidene bisphenol 20 parts Polyvinyl alcohol (10% aqueous solution) 20〃Water
601
1 [Dispersion-B] 4.4'-Butylidene-bis-(3-methyl-6-tert-butylphenol) 20 parts Polyvinyl alcohol (10% aqueous solution) 20 Il water
6
0〃Prepared as above [Dispersion liquid-A 320 parts, [
Dispersion-8] 80 parts of each were taken and mixed and stirred to obtain a low-temperature thermosensitive coloring coating solution. - [Dispersion liquid-0120 parts, [
80 parts of Dispersion D) and 40 parts of Dispersion E were taken and mixed and stirred to obtain a high temperature thermosensitive coloring coating solution. Further, a decolorizing agent layer forming liquid for forming a decolorizing agent layer was prepared at the following ratio.

[Decolorizer layer forming liquid]

N,N'-isophthaloyldi(N-cyclohexyl-
N-methylamide) 20 parts 10% polyvinyl alcohol aqueous solution 201/
water
60! ! Further, the following components were pulverized and dispersed using a sand mill to prepare an overcoat forming liquid.

[Overcoat layer forming liquid]

Polyvinyl alcohol 10% aqueous solution 20 parts Silica powder 0,5//Zinc stearate Q, 1n water
IQtt
Next, the above-mentioned high-temperature color forming layer forming liquid was coated on a commercially available high-quality paper with a basis weight of about 42 g/rd so that the dye adhesion amount when dried was 0.5 g/m, and was dried to form a high-temperature color forming layer. The decolorizing layer forming liquid was applied on top to a dry adhesion amount of 3. A decoloring layer was formed by coating and drying to give Og/rn'.

Further, the low-temperature coloring layer forming liquid was applied thereon so that the amount of dye attached when dried was 0.4 g/rd, and was dried to form a low-temperature coloring layer. Furthermore, the overcoat layer forming solution was applied thereon so as to have a dry coating amount of 2.0 g/rrf and dried to form an overcoat layer. Then, the smoothness is 10
A two-color heat-sensitive recording material of the present invention was obtained by calendering to give a time of 0.00 to 2000 sec.

Example 2 A two-color heat-sensitive recording material of the present invention was obtained in the same manner as in Example 1, except that 100 parts of [Dispersion-D] and 20 parts of [Dispersion-E] were used in Example 1. Ta.

Example 3 [Dispersion-E] in Example 1 was changed to [Dispersion-E] below.
A two-color heat-sensitive recording material of the present invention was obtained in the same manner as in Example 1, except that the material was replaced with the following.

[Dispersion-E1] 4.4'-isopropylidene bis(2,6-dibromophenol) 20 parts Polyvinyl alcohol (10% aqueous solution) 20 Water
60
Example 4 A two-color heat-sensitive recording material of the present invention was obtained in the same manner as in Example 3, except that 100 parts of [Dispersion-0] and 20 parts of [Dispersion-21] used in Example 3 were used. Ta.

Comparative Example 1 The high temperature thermosensitive coloring coating liquid in Example 1 was replaced with a high temperature thermosensitive coloring coating liquid obtained by mixing and stirring 20 parts of [Dispersion-〇] and 120 parts of [Dispersion liquid-〇]. A comparative two-color heat-sensitive recording material was obtained in the same manner as in Example 1 except for this.

Comparative Example 2 A comparative two-color heat-sensitive recording material was obtained in the same manner as in Example 1, except that 60 parts of [Dispersion-D] and 40 parts of [Dispersion-E] used in Example 1 were used. Ta.

Comparative Example 3 A comparative two-color heat-sensitive recording material was prepared in the same manner as in Example 1, except that 60 parts of [Dispersion-D] and 40 parts of [Dispersion-E] used in Example 3 were used. I got it.

The two-color heat-sensitive recording materials of Examples and Comparative Examples obtained as described above were subjected to printing simulator L having a line head of 8 dots/mm: Te, 0.6 W/dot, sub-scanning 7.7
A color development test was conducted at 1ine/++++ and one line recording time of 10 m5ec. In addition, each sample was heated at 40℃90%R1 (
, Leave the image under dry conditions at 50°C for 24 hours, and the image will fade.
A fog test was conducted on the background area.

The results are shown in Table-1. Also, the concentration measurement is Macbeth RD514.
Type (Filter 106: Background filter V-58:
Red coloring> was used.

Table 1 [Effects] As can be seen from Table 1, the two-color thermosensitive recording material of the present invention provides clear high-temperature colored images with high color density, and has excellent storage stability such as heat resistance and moisture resistance. It is an excellent two-color heat-sensitive recording material.

Claims (1)

[Claims] (1) In a two-color thermosensitive recording material in which a high-temperature coloring layer, a decoloring layer, and a low-temperature coloring layer are laminated in that order on a support, a compound represented by the following general formula (A) is used as a color developer for the high-temperature coloring layer. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(A) (In the formula, Z is -S-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼ where R_1, R_2, R_3 and R_4 represent H or an alkyl group having 1-4 carbon atoms.) ▲Mathical formula, There are chemical formulas, tables, etc.▼(B) (In the formula, R_1, R_2, R_3, R_4, R_5 and R_6 represent H or an alkyl group having 1 to 4 carbon atoms.) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (C) (In the formula, Y represents an alkylene group having 1 to 4 carbon atoms, -S- or -SO_2-, and X represents a halogen.) (2) The total amount of color developer in the high-temperature coloring layer is The two-color heat-sensitive recording material according to claim 1, wherein the amount is 6 parts by weight or more per 1 part by weight of the dye.