JPS62299382A - Two color thermal recording material - Google Patents

Abstract

PURPOSE:To enhance a high-temperature developed color density, suppress ground fogging after moisture-proof preservation and enhance contrast, by using a color developer in a high-temperature color forming layer in the amount of at least a specified number of times the amount of a dye in the layer. CONSTITUTION:A color developer in a high-temperature color forming layer is used the amount of at least 6 times the amount of a dye in the layer, in a two-color thermal recording material comprising the high-temperature color forming layer, a decolorizing layer and a low-temperature color forming layer sequentially laminated on a support base. The color developer is preferably a compound of the formula, wherein Z represents -S- or the like, and each of R1-R4 represents H or a 1-4C alkyl. With the color developer in the high-temperature color forming layer used in an amount of at least 6 times that of the dye in the layer, it is possible to control the lowering in the developed color density by the effect of a decolorizing agent in the high- temperature color forming layer upon high-temperature color forming. Accordingly, it is possible to obtain a two-color thermal recording material capable of low- temperature color forming with a sufficient developed color density and high- temperature color forming with clear hue and a sufficient developed color density.

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 broadly classified into the following two types: Divided into 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 is disclosed in Japanese Patent Publication No. 49-69 and Japanese Patent Publication No. 49-4342.

Special Publication No. 49-27708, Japanese Patent Publication No. 48-86543
No. 49-65239, JP-A No. 49-65239, etc.
The latter ones are published in Japanese Patent Publication No. 50-17865, Japanese Patent Publication No. 17866-1982, Japanese Patent Publication No. 51-29024.
Publication No. 1987-87542, Japanese Patent Publication No. 1987-87542
These are disclosed in Japanese Patent Publication No. 18048, Japanese Patent Publication No. 55-36519, etc., respectively.

However, in the case of the former multicolor thermosensitive recording paper,
When coloring at a high temperature, the color tones that can be concretely achieved in order to mix the color with the color tone of the low temperature coloring layer are limited to black threads where the high temperature coloring tone is strong, 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 color tones can be freely selected, but when coloring at high temperatures, high aliphatic alcohols, polyethers, polyethylene glycol derivatives,
Acetamide, stearamide diphthalonitrile as nitrogen-containing organic compounds, guanidine derivatives, morpholine derivatives, etc. as amine derivatives are used. but,
Such multicolor recording materials are affected by temperature, humidity, etc., and it is difficult to maintain a stable image during storage, particularly in image stability in high-temperature coloring areas.

Further, a decoloring agent which has better decoloring efficiency and stability than the above-mentioned decoloring agents is disclosed in Japanese Patent Application No. 59-241333.

Patent application No. 59-273816, Patent application No. 11377-1983
No., Patent Application No. 11378/1980, Patent Application No. 6489/1983
It is proposed in No. 4.

However, in two-color heat-sensitive recording materials using these decolorizing agents, during high-temperature coloring, the decolorizing agent not only decolorizes the coloring of the low-temperature coloring layer, but also erases the coloring of the high-temperature coloring layer. As a result, the color of the high-temperature color-forming layer is erased, resulting in a decrease in the color density of the high-temperature color-forming layer and an unclear color tone.

Also, if you try to obtain sufficient high-temperature coloring by adjusting the amount of decolorizing agent, the coloring of the low-temperature coloring layer will not be sufficiently erased during high-temperature coloring, resulting in a mixed state of high-temperature coloring and low-temperature coloring, resulting in two colors. There was a problem with separability.

〔the purpose〕

The present invention provides a two-color heat-sensitive recording material with high density and good contrast, that is, a two-color heat-sensitive recording material with high coloring density in the coloring layer of low-temperature and high-temperature coloring layers, which can obtain a clear hue, and with less background fogging during storage. The purpose is to provide heat-sensitive recording materials.

〔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 thermosensitive recording material is provided, characterized in that the color developer in the high-temperature color-forming layer is used in an amount that is at least 6 times the amount of dye in the high-temperature color-forming layer.

The color developer used in the present invention is represented by the following general formula (A):
Compounds represented by are preferred.

R□, R3 and R4 represent H or an alkyl group having 1 to 4 carbon atoms. ) Specific examples of the compound represented by the general formula (A) preferably used in the present invention include the following.

CH, CH.

In the present invention, since the developer in the high-temperature color-forming layer is used at least 6 times the amount of dye in the high-temperature color-forming layer, it is possible to control the decrease in color density due to the influence of the decolorizing agent in the high-temperature color-forming layer during high-temperature color development. Thus, it is possible to obtain a two-color heat-sensitive recording material that develops low-temperature color with sufficient color density and high-temperature color development with sufficient color density and clear hue without color mixture.

If the amount of the color developer in the high-temperature coloring layer is less than 6 times the amount of dye in the high-temperature coloring layer, sufficient color density and clear hue cannot be obtained due to the influence of the decolorizing agent during high-temperature coloring.

In the present invention, examples of the color developer contained in the high-temperature coloring layer and the low-temperature coloring layer include N,N'-diphenylthiourea, N-p-ethylphenyl-N'-phenylthiourea, and N-p-butylphenyl. -N'-Phenylthiourea, N, N' -Chlorophenylthiourea, N
, N'-di-p-chlorophenylthiourea, N, N
'-di-rtr-trifluoromethylphenylthiourea, N,N'-di-m-methylphenylthiourea, 4,
4'-isopropylidene diphenol, 4,4'-isopropylidene bis(2-chlorophenol), 4.
4'-isopropylidene bis(2,6-dibromophenol), 4.4'-isopropylidene bis(2,6-dibromophenol)
-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, novolac-type phenol resin, 2
, 2'-thiobis(4,6-dichlorophenol), catechol, resorcinol, hydroquinone, biloganol,
Phloroglucin, phloroglycin carboxylic acid, 4-te
rt-octylcatechol, 2,2'-methylenebis(4-chlorophenol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol),
2.2'-dihydroxydiphenyl, ethyl p-hydroxybenzoate, propyl p-hydroxybenzoate, P-
Butyl hydroxybenzoate, benzyl p-hydroxybenzoate, p-chlorobenzyl p-hydroxybenzoate, O-chlorobenzyl p-hydroxybenzoate, p-
p-methylbenzyl hydroxybenzoate, n-octylbenzoic acid p-hydroxybenzoate, zinc salicylate, l-hydroxy-2-naphthoic acid, 2-hydroxy-
6-naphthoic acid, zinc 2-hydroxy-6-naphthoate, 4-hydroxydiphenylsulfone, 4-hydroxy-42-chlorodiphenylsulfone, bis(4-hydroxyphenyl)sulfide, etc. are used. In particular, when the compound represented by the above-mentioned general formula (A) is used as a color developer for a high-temperature coloring layer, a layer with high coloring density and little background fogging can be obtained.

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. 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-diethylaminophenyl.

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-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-(a-trichloromethylanilino)fluoran, 3-diethylamino-7 -(o-chloroanilino)fluorane.

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'- 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-trifluoro methylanilino)fluorane, 3-pyrrolidino-7-(di-p-chlorphenyl)methylaminofluorane.

3-diethylamino-5-chloro-7-(α-phenylethylamino 3-(N-ethyl-p-toluidino)-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-(0-methoxycarbonyl phenylamino)fluoran, 3-diethylamino-5-methyl-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-piperidinofluorane, 2-
Chloro-3-(N-methyltoluidino)-7-(p-〇-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, specific examples of particularly preferable leuco dyes to be contained in the high temperature coloring layer include 3-diethylamino-7-chlorofluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-cyclohexyl Examples include amino-6-chlorofluoran, 3-diethylaminobenzo[α]fluoran, 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), (If), (II
Compounds represented by I), (IV) and (V), compounds having three or more amide groups in the molecule, or two or more amide groups and one or more tertiary amino groups, N ,
Preference is given to using N'-dithiocaprolactam and the like.

General formula (IV) In the general formulas (1), (■) and (III), R 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, the cycloalkyl is cyclohexyl, and the aryl is phenyl, tolyl, Examples of the aralkyl include xylyl and the like, and examples of the aralkyl include benzyl and phenethyl. These substituents may further have other substituents, such as alkyl, aryl, halogen, alkoxy, aryloxy, acyl,
Acyloxy, alkoxycarbonyl, carbamoyl,
Examples include acylamino. Also, the general formula (
One or more substituents such as alkyl, aryl, halogen, alkoxy, aryloxy, acyl, acyloxy, alkoxycarbonyl, carbamoyl, and acylamino may be bonded to the piperazine ring in I) to (m). .

Specific examples of the compound represented by the general formula (1) 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(p-chlorobenzenesulfonyl)piperazine.

N,N'-bis(0-chlorobenzenesulfonyl)piperazine.

N,N'-bis(1m-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, etc.

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

N,N'-bis(butyroyl)piperazine, N,N'
-Bis(hexyloyl)piperazine.

N, N'-bis(n-ofthyroyl)piperazine, N
, N'-bis(tertiary-oftyroyl)piperazine.

N,N'-bis(lauriloyl)piperazine.

N,N'-bis(stearoyl)piperazine.

N,N'-bis(pivaloyl)piperazine, N,N'
-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.

N,N'-bis(benzoyl)piverandin, 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), R2, R3 and R4 represent substituted or unsubstituted alkyl, cycloalkyl, aryl or aralkyl, and R and R2 or R1 and R4 are
The ends can also be joined together to form a ring. Examples of the alkyl include straight or branched chains having 4 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 are.

Furthermore, it may have other substituents, and examples of such substituents include alkyl, aryl, alkoxy, acyl, halogen, acylamino such as benzor-rulamino and acetylamino, alkoxycarbonyl,
Examples include carbamoyl, aryloxy, aralkyloxy and the like. A is a fatty acid group or an aromatic group, and in the case of an aliphatic group, it usually has 1 substituted or unsubstituted carbon number.
-8 alkylene, and in the case of an aromatic group, it is a substituted or unsubstituted arylene such as phenylene, tolylene, xylylene, etc. In this case, the substituent is the above-mentioned halogen, acylamino, alkoxycarbonyl, carbamoyl, aryl. Oxy, aralkyloxy, etc. are mentioned.

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

N,N,N'N'-tetrabutylsuccinic acid diamide, N,N,N'N'-tetraoctylsuccinic acid diamide, N,N,N'N'-tetralaurylsuccinic acid diamide.

N,N,N'N'-tetrastearylsuccinic acid diamide, N,N,N'N'-tetraphenyladipic acid diamide, N,N,N'N'-tetra-p-butylphenyladipic acid diamide, N , N, N'N' -tetrabutyl adipate diamide, N, N, N'N' -tetraoctyl adipate diamide, N, N, N'N' -tetralauryl adipate diamide, N, N, N'N'-tetrastearyladipate diamide, N,N'-dicyclohexyl-N,N'-dimethylsuccinic acid diamide.

N,N'-isophthaloyl bispyrrolidine, N,N'
-phthaloylbispyrrolidine, N,N'-terephthaloylbis-diethylamine, N,N'-isophthaloylbis-diethylamine, N,N'-phthaloylbis-diethylamine, N,N'-terephthaloylbis-
Dipropylamine, 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), R1 and R2 represent alkyl, cycloalkyl, aryl, or aralkyl which may have a substituent, and the alkyl is usually a linear or branched chain having 1 to 18 carbon atoms. Examples of the cycloalkyl include cyclohexyl, examples of the aryl include phenyl, tolyl, and xylyl, and examples of the aralkyl 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. Y 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(hexyloylaminopropyl)piperazine, N-benzoylaminopropyl-N'-cyclohexylaminoethylpiperazine.

N-benzoylaminopropyl-N'-benzoylaminobutylpiperazine, N-(P-chlorobenzoylaminoamino) -N'-
Benzoylaminopropylpiperazine.

N-cyclohexyloylaminopropyl-N'-cyclohexyloylaminobutylpiperazine and the like.

Further, specific examples of the compound having three or more amine 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-dipropylenetriamine.

N, N', N', N-tetrabenzoyl-triethylenetetramine, 1,7-dibenzoyl-4-methyl-diethylenetriamine.

1.9-dibenzoyl-5-methyl-dipropylenetriamine, 1.7-di-α-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, such as 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, talc, and surface-treated inorganic fine powders such as calcium and silica. , 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. , various waxes, condensates of aromatic carboxylic acids and amines,
Benzoic acid phenyl ester, higher linear glycol, 3.
50-200 of dialkyl 4-epoxy-hexahydrophthalate, higher ketones, other thermofusible organic compounds, etc.
Examples include those with a melting point of about ℃.

Further, if necessary, in order to improve the stability of the high-temperature coloring layer over time, an intermediate layer mainly composed of a thermofusible substance or resin may be provided between the high-temperature coloring layer and the decoloring layer.

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 dispersion liquid was prepared by dispersing the following compositions using a sand grinder.

[A□liquid]

3-diethylamino-7-chlorofluorane (red dye)
10 parts polyvinyl alcohol 1 part aqueous solution 1011 water
30//(A, liquid) 3-(N-n-octyl-N-iso-propyl)amino-6-methyl-7-anilite fluorane 10 parts Polyvinyl alcohol 10% aqueous solution IQn water

30 (B, liquid) 1.1-His-(4-hydroxyphenyl)cyclohexane 30 parts Polyvinyl alcohol 10% aqueous solution 3Qn water
90I!
(Liquid B2) 4.4'-thiobis(3-methyl-6-t-butyl)
Phenol 30 parts Polyvinyl alcohol 10% aqueous solution 3Qn water
90
1/(Liquid B3) 4.4'-dihydroxydiphenylsulfone 20 parts polyvinyl alcohol aqueous solution 20II water
9
01I [Liquid B4] Bisphenol A 30 parts Polyvinyl alcohol 10% aqueous solution 30 parts Water

90/l [Liquid C] Silica powder 20 parts Polyvinyl alcohol 10% aqueous solution 201F water

6Qn [Liquid D] Rose benzyl biphenyl 20 parts Polyvinyl alcohol 10% aqueous solution 20 Water
6
0 [Liquid E] 10% polyvinyl alcohol aqueous solution 20 parts Silica powder 0.5 Zinc stearate 0.1 Water
10
[Liquid F] N, N'-isophthaloyl di(N-cyclohexyl N
-Methylamide) 20 parts polyvinyl alcohol 1 part aqueous solution 20 parts water
6
0 [Example 1] (Liquid A1): (Liquid B): [Liquid C] = 1:6:
3 and the first thermosensitive coloring layer [high temperature coloring layer] coating solution, (A2 solution) = (B, solution): [C solution]: (D,
A second heat-sensitive coloring layer (low-temperature coloring layer) coating solution was prepared by mixing in a ratio of 1:2:1.5:3.

The first heat-sensitive coloring layer coating solution was coated on 42 g/m high-quality paper so that the leuco dye adhesion amount was 0.5 g/m, and then dried, and then [Liquid F] was applied so that the dry adhesion amount was 3 g/m. After coating to form a decoloring layer, a second thermosensitive coloring layer coating solution was applied such that the amount of leuco dye deposited was 0.4 g/rrr, and dried to form a second thermosensitive coloring layer.

Finally, use [Liquid E] on top of this to achieve a dry adhesion amount of approximately 2g/
The two-color heat-sensitive recording material of the present invention was prepared by coating to form a protective layer and calendering the surface.

[Example 2] A two-color heat-sensitive recording material of Example 2 was prepared in the same manner as in Example 1 except that [Liquid 8] was used instead of [Liquid B1].

[Example 3] The first heat-sensitive coloring layer coating liquid of Example 1 was changed to “A0 liquid): (Bl
A color heat-sensitive recording material of Example 3 was prepared in the same manner as in Example 1, except that the mixtures were mixed at a ratio of 1:9:3.

[Comparative Example 1] The first heat-sensitive coloring layer coating liquid of Example 1 (A, liquid): CB,
A two-color heat-sensitive recording material of Comparative Example 1 was prepared in the same manner as in Example 1 except that the mixtures were mixed at a ratio of [liquid]:[liquid C]=1:4:3.

[Comparative Example 2] The first thermosensitive coloring layer coating solution of Example 1 was [Liquid A1]: [B3
A two-color heat-sensitive recording material of Comparative Example 2 was prepared in the same manner as in Example 1, except that the mixtures were mixed at a ratio of [Liquid]:[Liquid C] = 1:4:3.

Next, these two-color heat-sensitive recording materials were printed at 1.6 W/mm in a print simulator with an 8 dot/mm line head.
dat, a sub-scan of 7.71 in/mm, and a recording time of 1 line of 10 m5 ec. In addition, each print sample and background sample were tested at 40℃ and 90%RH (humidity test).
A storage test was conducted by leaving the sample under these conditions for 24 hours. The results are shown in Table-1. In addition, the density measurement is performed using Macbeth RD514 type <Filter 1 + 1106;
8; Red coloring> was used.

Table 1 [Effects] As can be seen from Table 1, the two-color heat-sensitive recording material of the present invention has a higher high-temperature color density (red color density) and less background fogging after humidity-resistant storage than conventional materials. It can be seen that this is a two-color heat-sensitive recording material with high contrast.

Claims (2)

[Claims] (1) In a two-color thermosensitive recording material in which a high-temperature coloring layer, a color erasing layer, and a low-temperature coloring layer are laminated in that order on a support, the amount of color developer in the high-temperature coloring layer is at least 6 times the amount of dye in the high-temperature coloring layer. A two-color heat-sensitive recording material characterized in that it is used. (2) The two-color heat-sensitive recording material according to claim 1, wherein the color developer of the high-temperature coloring layer is represented by the following general formula. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, Z represents -S-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, R_1, R_2, R_3 and R_4 represents H or an alkyl group having 1 to 4 carbon atoms.)