JPS62294587A - Two-color thermal recording material - Google Patents

Abstract

PURPOSE:To provide a two-color thermal recording material obtaining a sharp developed two-color image, excellent in preservability such as heat resistance and humidity resistance, etc. and reduced in background fogging, by using a compound represented by a specific formula as the coupler of a high temp. color forming layer and further using a metal dithiocarbamate or metal xanthate in the high temp. color forming layer. CONSTITUTION:A two-color thermal recording material is constituted by successively laminating a high temp. color forming layer, a color erasing layer and a low temp. color forming layer to a support and, in the high temp. color forming layer thereof, a coupler represented by formula (I) (wherein Z is -S-, A or B and R1, R2, R3 and R4 are H or a 1-4C alkyl group) is pref. set to 6pts. or more by wt. of 1pt. of a leuco dye used and the total quantity of the coupler, metal dithiocarbamate and metal xanthate is pref. set to 7pts.wt. of 1pt. of the leuco dye. When said quantity is 7pts.wt. or less, the color erasing effect of a color erasing agent becomes marked when a high temp. developed color image is formed and a sharp high temp. developed color image is not obtained and stability during preservation becomes inferior.

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 and documents, but also for recording various types of information such as computers, facsimiles, telex machines, etc., as well as output records from A+11 machines. It is used in various fields, but depending on the recording/use, in order to display particularly necessary data or numbers more clearly, it is possible to record by changing the color of that part (display color) from the color of other parts. Of course, this is desirable.

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, Japanese Patent Publication No. 4342-1972, Publication No. 27708-1977,
JP-A-48-86543.

It is described in Japanese Patent Publication No. 49-65239, etc., and the latter is described in Japanese Patent Publication No. 50-17865, Japanese Patent Publication No. 50-17866, Japanese Patent Publication No. 51-29024,
Japanese Patent Publication No. 51-87542, Japanese Patent Publication No. 50-1804
8, 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, phthalonitrile 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.

〔the purpose〕

The present invention is capable of producing clear two-tone color development, has excellent storage stability such as heat resistance and temperature resistance, and has a two-color coloring system with less fogging on the background.
The purpose is to provide a color thermosensitive recording material.

〔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 (8) is used as a color developer in the high-temperature coloring layer, and a dithiocarbamate metal salt or a xanthate metal salt is further used in the high-temperature coloring layer. is provided.

R2H.

and R□, R2, R3 and R4 represent H or an alkyl group having 1 to 4 carbon atoms. ) Conventionally, phenol derivatives, p-benzylbenzoic acid ester derivatives, thiourea derivatives, etc. have been proposed as color developers for the high-temperature coloring layer of two-color thermosensitive recording materials. When stored in high temperature or high humidity environments for a long period of time, products that contain these products may cause problems with their shelf life, such as fogging of the skin and discoloration if fingerprints or the like get on them.
Furthermore, when a two-color image is formed, the decoloring agent also acts on the high-temperature coloring layer, making it impossible to obtain a clear high-temperature coloring image.

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 for a high-temperature coloring layer, there is no coloration due to background fogging or fingerprints during long-term storage. Although it has been found that clear high-temperature colored images can be obtained, it has been found that even in this case, there are problems in that the high-temperature colored images have poor stability in heat resistance and humidity resistance, and a significant decrease in density. In order to improve this point, the present inventors have conducted intensive research and found that the above general formula (A) is used in the high temperature coloring layer.
The present inventors have discovered that these drawbacks can be overcome by containing the compound represented by the formula and a dithiocarbamate metal salt or a xanthate metal salt, and have completed the present invention.

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

Further, examples of the dithiocarbamate metal salts and xanthate metal salts used in the present invention include the following compounds.

Zinc dimethyldithiocarbamate Zinc dibutyldithiocarbamate Zinc N-ethyl-N-phenyldithiocarbamate Zinc diethyldithiocarbamate Tellurium dibutyldithiocarbamate Nickel xanthate Zinc lead xanthate In addition, in the present invention, in the high temperature coloring layer, it is used in the high temperature coloring layer. The color developer represented by the general formula (A) is 6 parts by weight or more per 1 part by weight of the leuco dye used, and the total amount of the color developer and the dithiocarbamate metal salts or xanthate metal salts is 7 parts by weight or more. It is preferable.

If it is less than this, the influence of the decolorizing effect of the decoloring agent becomes significant during the formation of a high-temperature color image, making it impossible to obtain a clear high-temperature color image and worsening the stability during storage.

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'-di-m-trifluoromethylphenylthiourea, N,N'-di-m-methylphenylthiourea, 4,4'-isopropylidenediphenol, 4,4'-isopropy Redenbis (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'-cyclohexylidenebis(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, pyroganol, phloroglucin, phloroglycin carboxylic acid, 4-tert-octylcatechol, 2,2'-methylenebis(4-chlorophenol), 2,2'-methylenebis(4-methyl-6-
tert-butylphenol), 2,2'-dihydroxydiphenyl, ethyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, p-hydroxybenzoic acid- P-glolbenzyl, ρ-hydroxybenzoic acid-0-chlorobenzyl, P-hydroxybenzoic acid-ρ-methylbenzyl, P-hydroxybenzoic acid-n-
Octylbenzoic acid, zinc salicylate, 1-hydroxy-
2-naphthoic acid, 2-hydroxy-6-naphthoic acid, 2
-Zinc hydroxy-6-naphthoate.

4-hydroxydiphenylsulfone, 4-hydroxy-
4'-chlorodiphenyl sulfone, 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. 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(ρ-dimethylaminophenyl)-6-chlorphthalide, 3.3-bis(p-dibutylaminophenyl)phthalide, 3-cyclohexylamino-6-chlor Fluoran, 3-dimethylamino-5,7-dimethylfluoran, 3
-diethylamino-7-chlorofluorane.

3-diethylamino-7-methylfluorane, 3-diethylamino-7,8-benzfluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-(N-ρ-toly-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-(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)fluoran, 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)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-(0-methoxycarbonylphenylamino)fluoran, 3-diethylamino-5-methyl-7-( α-phenylethylamino)fluorane, 3-diethylamino-7-piperidinofluorane, 2-
Chloro-3-(N-methyltoluidino)-7-(p-0-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 preferred leuco dyes to be contained in the high temperature coloring layer include 1, 3-diethylamino-7-chlorofluoran, 3-diethylamino-7-chlorofluoran,
Examples include 6-methyl-7-chlorofluoran, 3-cyclohexylamino-6-chlorofluoran, and 3-diethylaminobenzo[α]fluoran.

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 (f), (II), (II
Compounds represented by I), (TV) 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.

K Yoichi 5tJ2-LN LN-λ-2℃J General formula (m) General formula ([V) General formula (V) In the above general formulas (1), (■) and (III), R and R2 is alkyl, cycloalkyl, aryl or aralkyl which may have a substituent, and X is carbonyl or sulfonyl. The alkyl represented by R1 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, xylyl, etc. Examples of aralkyl include benzyl and phenethyl. These substituents can further have other substituents, such as alkyl, aryl, halogen, alkoxy, aryloxy, acyl,
Acyloxy, alkoxycarbonyl, carbamoyl,
Examples include acylamino. Also, the general formula (
The piperazine ring in 1) to (I[I) also includes alkyl, aryl, halogen, alkoxy, aryloxy,
One or more substituents such as acyl, acyloxy, alkoxycarbonyl, carbamoyl, and acylamino may be bonded.

Specific examples of the compound represented by the general formula (I) 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'-benzoyl piperazine, 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 (II) include the following.

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

N,N'-bis(ρ-isopropylbenzenesulfonyl)piperazine, N,N'-bis(P-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 (III) 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, N g N'
-bis(cyclohexyloyl)piperazine, N, N'
-bis(p-methylcyclohexyloyl)piperazine, N,N'-bis(P-methylphenylacetyl)piperazine, NgN'-bis(phenylacetyl)piperazine.

N,N'-bis(phenylpropionyl)piperazine, N,N'-bis(benzoyl)piperazinone, N,N
'-bis(phenoxyacetyl)piperazine, N,N
'-bis(P-talolopenzoyl)piperazine 5,
N,N'-bis(2-phenoxypropionyl)
Piperazine TJI11 In the general formula (TV), R1, R, , R, and R4 represent substituted or unsubstituted alkyl, cycloalkyl, aryl, or aralkyl, and R1 and R2 or R3 and R4 each have their terminals They can also be combined 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 are.

It may further have other substituents, such as alkyl, aryl, alkoxy, acyl, halogen, acylamino such as benzoylamino, acetylamino, alkoxycarbonyl, carbamoyl, aryloxy, etc. , aralkyloxy, and the like. A is a fatty acid group or an aromatic group, and in the case of an aliphatic group, it is usually substituted or unsubstituted and has 1 to 1 carbon atoms.
8, and in the case of an aromatic group, it is substituted or unsubstituted arylene such as phenylene, tolylene, xylylene, etc. In this case, the substituent is the above-mentioned halogen, acylamino, alkoxycarbonyl, carbamoyl, aryloxy. , aralkyloxy, and the like.

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-2-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'
-phthaloyl bispyrrolidine, N,N'-terephthaloyl bis-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. The alkyl usually includes a straight chain or branched chain having 1 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, such as alkyl, aryl, halogen, alkoxy, aryloxy, aralkyloxy, acyl, acyloxy, alkoxycarbonyl, carbamoylcyl, etc. Examples include substituents such as amino.

Yl and Y2 are linear or branched alkylene groups having 1 to 18 carbon atoms.

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(hexylo ylaminopropyl) piperazine.

N-benzoylaminopropyl-N'-cyclohexylaminoethylpiperazine, N-benzoylaminopropyl-N'-benzoylaminobutylpiperazine, N-(P-chlorobenzoylaminoamino)-N'-benzoylaminopropyl biverazine, N-cyclohexyloylaminopropyl-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'hribenzoyl-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-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, 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 / Maleic anhydride copolymer alkali salt, imbutylene / Maleic anhydride copolymer alkaline salt, polyacrylamide, sodium alginate, gelatin, casein, and other water-soluble polymers, as well as polyvinyl acetate, polyurethane, styrene/butadiene, etc. Latexes such as polymers, polyacrylic acid, polyacrylic esters, vinyl chloride/vinyl acetate copolymers, polybutyl methacrylate, ethylene/vinyl acetate copolymers, styrene/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 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 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 thermoplastics. Examples include melting organic compounds having a melting point of about 50 to 200°C.

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.

CA, liquid] 3-diethylamino-7-chlorofluoran (red dye)
10 parts Polyvinyl alcohol 10% aqueous solution 10! I
water
30! 1 [Liquid A2] 3-(N-n-octyl-N 1so-propylamino-6-methyl-7-anilinofluorane 10 parts Polyvinyl alcohol 10% aqueous solution 10//Water
3
Qn [B solution] 1.1-bis-(4-hydroxyphenyl)cyclohexane 30 parts Polyvinyl alcohol 10% aqueous solution 30 Water
90 copies [B2
Liquid] 4.4'-dihydroxydiphenylsulfone 30 parts 10% polyvinyl alcohol aqueous solution 3Qu water
90
n [C□liquid] Zinc N-methyl-N-phenyldithiocarbamate
20 parts polyvinyl alcohol aqueous solution 20 parts water
60 [Liquid C2] Zinc xanthate 20 parts Polyvinyl alcohol 10% aqueous solution 20 Water
60
# [Liquid D] Silica powder 20 parts Polyvinyl alcohol 10% aqueous solution 20 Water
6
0 [Liquid E] Rose benzyl biphenyl 20 parts Polyvinyl alcohol 10% aqueous solution 20 parts Water
60〃
[Liquid F] 10% polyvinyl alcohol aqueous solution 20 parts Silica powder Q, 5t + zinc stearate 0.1! l water
10
Il [Liquid G] N,N'-isophthaloyl di(N-cyclohexyl N
-Methylamide) 20 parts 10% polyvinyl alcohol aqueous solution 20 parts water
60 [Example 1] [A1 solution]: [B solution]: [C method]: [D solution] = 1:
Mix at a ratio of 6:1:3 to form the first thermosensitive coloring layer [high temperature coloring layer] coating solution, and [Liquid A2]: [Liquid 8]: [Liquid D].
: [Liquid E) =1. :2:1.5:3 to prepare a second heat-sensitive coloring layer (low-temperature coloring layer) coating solution. The first heat-sensitive coloring layer coating liquid 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 G] 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 and dried to form a second thermosensitive coloring layer such that the amount of leuco dye deposited was 0.4 g/I.

Finally, use [Liquid F] 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 applying the protective layer to form a protective layer and calendering the surface.

[Example 2] Cc2C2 liquid instead of [C0 liquid] in Example I]
A two-color heat-sensitive recording material of Example 2 was prepared in the same manner except that

[Comparative Example 1] The first thermosensitive coloring layer coating solution of Example 1 was [A solution]: [B,
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 D]=1:6:3.

[Comparative Example 2] The first thermosensitive coloring layer coating solution of Example 1 was changed to [〇〇 solution]: [B,
Liquid]: [Liquid D)=1. A two-color heat-sensitive recording material of Comparative Example 2 was prepared in the same manner as in Example 1 except that the mixture was mixed at a ratio of 4:3.

Next, these two-color heat-sensitive recording materials were printed in a printing simulator equipped with an 8 dot/mm line head.

1.6W/dot, sub-scanning 7.71ine/+n+n,
A color development test was conducted with a recording time of 1 line of 10+++ seconds. In addition, each print sample and background sample were heated at 40℃ and 90℃.
A storage test was conducted by leaving it for 24 hours under the conditions of air R1 ([humidity test] and 50°C dry (heat resistance test). The results are shown in the table below.
Shown in 1. In addition, the density measurement is performed using Macbeth RD514 type <filter TT106; background part, filter 1it-58
I used a color with a red color.

Table 1 [Effects] As is clear from Table 1, the two-color heat-sensitive recording material of the present invention has better image stability during storage and less background fog than the conventional two-color heat-sensitive recording material. It can be seen that it is.

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 is used as a color developer in the high-temperature coloring layer, 2, further characterized in that a dithiocarbamate metal salt or a xanthate metal salt is used in the high-temperature coloring layer.
Color thermosensitive recording material. ▲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.)