JPS63274586A - Dichromatic thermal recording material - Google Patents

Abstract

PURPOSE:To make the color development of both a high temperature color developing layer and a low temperature color developing layer uniform and effect higher dichromatic separation efficiency by laminating a high temperature color developing layer, a discharge layer and a low temperature color developing layer containing a surfactant of succinic acid sequentially on a support, thereby forming dichromatic thermal recording materials. CONSTITUTION:A high temperature color developing layer, a discharge layer and a low temperature developing layer containing a surfactant of succinic acid are sequentially laminated on a support such as high-quality paper to form dichromatic thermal recording materials. The recommendable surfactants of succinic acid are compounds expressed by the formula I (R represents on alkyl group having carbon atoms of 1-18 and preferably the 2-ethylhexyl group). As typical examples, Na-dimethylsulfosuccinate, Na-dihexylsulfosuccinate, etc. are used. As discharge agents, N-methyl-N'-phenylacetylpiperazine, N-N'-bis) benzenesulphonyl)piperazine, N-N'-bis(butyloyl)pyperazine, etc. may be mentioned.

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, it comprises: (1) a usually colorless or slightly pale leuco dye; 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 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 number, Special Publication No. 49-4342, Special Publication No. 49-277
No. 08, 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,
-17866 Publication, Special 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,
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, acetamide, stearamide, phthalonitrile as nitrogen-containing organic compounds, guanidine derivatives, morpholine derivatives as amine derivatives, etc. are used. However, in such a multicolor recording material, since there are multiple IIt heat-sensitive coloring layers, it is important that each layer is coated uniformly. is inverted. In particular, since the low-temperature coloring layer cannot be applied uniformly, the color tones of the low-temperature coloring layer are mixed, and the color tone of the high-temperature coloring layer also mixes with the color tone of the low-temperature coloring layer. Ta.

【the purpose〕

An object of the present invention is to provide a two-color thermosensitive recording material which can uniformly develop a blackish low-temperature coloring layer and a reddish high-temperature coloring layer and has excellent two-color separation without color mixing.

〔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 is provided, characterized in that the low-temperature coloring layer contains a succinic acid surfactant.

The succinic acid surfactant in the present invention includes:

Usually, a compound represented by the following general formula (1) is used.

In the above general formula (1), R represents a straight chain or branched alkyl group having 1 to 18 carbon atoms, preferably a 2-ethylhexyl group, and the alkyl group contains one or more ether bonds. As such a succinic acid surfactant, commercially available ordinary succinic acid surfactants can be used as appropriate.

Examples of the succinic acid surfactant represented by the general formula (1) used in the present invention include Na-di-methyl-
Sulfosuccinate, Na-di-ethyl-sulfosuccinate, Na-di-propyl-sulfosuccinate,
Na-di-butyl-sulfosuccinate, Na-dibenthyl-sulfosuccinate, Na-di-hexyl-
Sulfosuccinate, Na-di-heptyl-sulfosuccinate, Na-di-octyl-sulfosuccinate, Na-di(2-ethylhexyl)sulfosuccinate, Na-di-nonyl-sulfosuccinate, Na-
Di-decanyl-sulfosuccinate and the like can be mentioned.

It is desirable to use such a succinic acid surfactant in an amount of 0.01 to 0.06 parts per part of the leuco dye used in the low-temperature coloring layer.

In the present invention, by incorporating a succinic acid-based surfactant in the low-temperature coloring layer, the wettability of the low-temperature coloring layer coating solution is increased, and the uniform coating properties of the low-temperature coloring layer are improved. The layer can be uniformly colored, and since such a low-temperature coloring layer is uniformly decolored under high energy, the high-temperature coloring layer is also uniformly colored, and a colored image with excellent two-color separation and no color mixture can be obtained. Can be done.

Furthermore, in the present invention, an intermediate layer may be provided between the high-temperature coloring layer and the decoloring layer and between the decoloring layer and the low-temperature coloring layer, if necessary.

The softening point of the film-forming polymer binder contained in the intermediate layer is preferably around 100°C, more preferably 80°C to 120°C.
It is ℃. Examples of such binders include:

Examples include polyvinyl alcohol, polyurethane, hydroxyethyl cellulose, carboxymethyl cellulose, starch and its derivatives, polyvinylidene chloride, styrene/butadiene copolymer, vinyl chloride/vinyl acetate copolymer, styrene/butadiene/acrylic copolymer, etc. However, the present invention is not limited thereto.

The intermediate layer mainly contains the binder as described above, but each intermediate layer may also contain a thermofusible substance (such as a sensitizer) or a filler.

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'-Gien-chlorophenylthiourea, N,N
' -di-p-chlorophenylthiourea, N, N' -
1-trifluoromethylphenylthiourea, N, N'
-1-methylphenylthiourea, 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'-isopropylidenebis(2-tert-butylphenol), 4.4'
-5ee-butylidene diphenol, 4,4'-cyclohexylidene bis(2-methylphenol), 4-
tart-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, biloganol, phloroglucin, phloroglycine carboxylic acid, 4-tert-octylcatechol, z, z '
-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
-Chlorbenzyl, p-hydroxybenzoate-0-chlorobenzyl, p-hydroxybenzoic acid-p-methylbenzyl, p-hydroxybenzoic acid-n-octylbenzoic acid, zinc salicylate, ■-hydroxy-2-naphthoic acid,
2-hydroxy-6-naphthoic acid, 2-hydroxy-6
-zinc naphthoate, 4-hydroxydiphenylsulfone, 4-hydroxy-4'-chlorodiphenylsulfone,
In addition to bis(4-hydroxyphenyl) sulfide and the like, guanidine-based organic base color developers as shown below may also be 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-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-chlorofluoran.

3-(N-p-tolyl-N-dithylamino)-6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 2-(N-(3'- )-lifluoromethylphenyl)amino)-6-dinithylaminofluorane, 2-(
3,6-bis(diethylamino)-9-(o-chloroanilino)xantylbenzoic acid lactam).

3-diethylamino-6-methyl-7-(ig-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-anilinofluoran 3-diethylamino-6-methyl-7-anilinofluorane, 3-(N,N-diethylamino) -5-methyl-7-(
N.

N-dibenzylamino)fluoran, benzoylleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-virillospirane, 6'-bromo-3'-methoxy-benzoindolino-virillosvirane, 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-41-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-P-chlorophenyl)methylaminofluorane.

3-diethylamino-5-chloro-7-(α-phenylethylamino)fluoran.

3-(N-ethyl-p-toluidino)-7-(α-phenylethylamino)fluoran, 3-diethylamino-? -(o-methoxycarbonylphenylamino)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 included in the high temperature coloring layer include 3-diethylamino-7-chlorofluoran, 3-diethylamino-
Examples include 6-methyl-7-chlorofluoran, 3-cyclohexylamino-6-chlorofluoran, and 3-diethylaminobenzo[α]fluoran. Furthermore, in the high-temperature color forming layer, acylated lactone or sultone type acid leuco dyes as shown below can also be used in combination with the above-mentioned guanidine color developer.

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), (m
N,
Preference is given to using N'-dithiocaprolactam and the like.

General formula (U) General formula (I[r) General formula (IV) General formula (V) In the above general formulas (I), (n) and (III), R1 and R2 may have a substituent. It may be alkyl, cycloalkyl, aryl or aralkyl, and X is carbonyl or sulfonyl. The alkyl represented by R and R8 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 are.

Furthermore, it may have other substituents, such as alkyl, aryl, halogen, etc., as well as alkoxy, aryloxy.

Acyl, acyloxy, alkoxycarbonyl.

Examples include carbamoyl and acylamino.

Further, the piperazine rings in general formulas (1) to (III) include alkyl, aryl, halogen, alkoxy, aryloxy, acyl, and acyloxy.

One or more substituents such as alkoxycarbonyl, carbamoyl, and acylamino may be bonded.

Specific examples of the compound represented by the general formula (1) include the following.

N-Methyl-N'-phenylacetylpiperazine.

N-propyl-N'-phenylacetyl biverranine.

N-propyl-N'-benzoylpiperazine, N-butyl-N'-benzoylpiperazine.

N-cyclohexyl-N'-benzoylpiperazine, hexyl-N'-benzoylpiperazine, N-lauryl-N'-benzoylpiperazine, N-stearyl-N'
-Benzoylpiperazine.

N-phenyl-N'-benzoylpiperazine, N-benzyl-N'-benzoylpiperazine.

Tophenyl-N'-cyclohexyloylpiperazine.

N-phenyl-N'-acetylpiperazine.

N-phenyl-N'-lauroylpiperazine and the like.

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(p-isopropylbenzenesulfonyl)piperazine.

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

N,N'-bis(■-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 (m) 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, 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)viverandin, 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), R1, R, , R, and R4 represent substituted or unsubstituted alkyl, cycloalkyl, aryl, or aralkyl, and R□ and R2 or R5 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, and the cycloalkyl includes cyclohexyl.

Examples of aryl include phenyl, tolyl, xylyl, etc., and examples of aralkyl include benzyl, phenethyl, etc. These substituents are.

It may further have other substituents, such as alkyl, aryl, alkoxy, acyl, halogen, acylamino such as benzoylamino, acetylamino, alkoxycarbonyloxy, aralkyloxy, etc. etc. can be mentioned. A
is a fatty acid group or an aromatic group, and in the case of an aliphatic group, it is usually substituted or unsubstituted fullkylene having 1 to 8 carbon atoms,
In the case of aromatic groups, they are substituted or unsubstituted arylene such as phinidine, tolylene, xylylene, etc. In this case, substituents include the above-mentioned halogen, acylamino, alkoxycarbonyl, carbamoyl, aryloxy, alkyloxy, etc. Examples include alkyloxy.

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 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-butylphenyladipate diamide.

N,N,N'N'-tetrabutyladipate diamide.

N,N,N'N'-tetraoctyladipate diamide.

N,N,N'N'-tetralauryladipic acid diamide.

N,N,N'N'-tetrastearyladipate diamide.

N,N'-dicyclohexyl-N,N'-dimethylsuccinic acid diamide.

N,N'-isophthaloyl bispyrrolidine.

N,N'-phthaloylbis-pyrrolidine, 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'- isophthaloyl bis-dicyclohexyl-amine, etc.

In the general formula (V), R1 and R3 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.

In addition to aryl and halogen, substituents such as alkoxy, aryloxy, aralkyloxy, acyl, acyloxy, alkoxycarbonyl, carbamoyl, and acylamino are mentioned.aYl and Y are linear or branched carbon atoms of 1 to 18 is an alkylene group.

A specific example of such a compound is as follows.

Examples include:

N,N'-bis(benzoylaminoethyl)piperazine, N,N'-bis(benzoylaminoprovil)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'-cyclohexyloylaminobutyl biverazine and the like.

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

These include:

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-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.

Other decolorizing agents include polyether, polyethylene glycol derivatives, solid alcohol, guanidine derivatives,
Morpholine derivatives can be used.

The decolorizing agent used in the present invention may be used alone or in the form of a mixture of two or more, and these are usually white solids that are stable in the air. Those having a melting point in the range of 120 to 250°C are preferably used.

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, acrylic amide/acrylic ester copolymer, acrylic amide/acrylic 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, if necessary, auxiliary additive components commonly used in this type of heat-sensitive recording material, such as fillers, surfactants, thermofusible substances ( or lubricant), etc. can be used in combination. In this case, as a filler.

For example, calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate,
Examples include fine inorganic powders such as clay, talc, and surface-treated calcium and silica, as well as fine organic powders such as urea-holimaline resin, styrene/methacrylic acid copolymer, and polystyrene resin. As a fusible substance, 1
For example, in addition to higher fatty acids or their esters, amides, or metal salts, various waxes, condensates of aromatic carboxylic acids and amines, and benzoic acid phenyl esters.

Examples include higher linear glycols, dialkyl 3,4-epoxy-hexahydrophthalates, higher ketones, and other heat-fusible organic compounds having a melting point of about 50 to 200°C.

[Examples] 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.
Dispersions A to D were prepared by pulverizing and dispersing to a particle size of 3 μm.

[Dispersion liquid-A]

3-(N-ethyl-N-amylamino)-6-methyl-
7-anirite fluorane (black) 20 parts 10%
Hydroxyethylcellulose aqueous solution 2o water
60/
F [Dispersion-B] 3.3-Dichlorophenylthiourea 10 parts Calcium carbonate 1 o Polyvinyl alcohol (10% aqueous solution) 2 o Water
6o [Dispersion liquid-
B] 10% hydroxyethyl cellulose aqueous solution 2 o water

60# [Dispersion-B] Bisphenol A 10 parts Calcium carbonate 1o 10% hydroxyethyl cellulose 15# Water
65# [Dispersion-B] Water
95 10 parts of dispersion A prepared as above, 870 parts of dispersion, 1 part of solution E, and 19 parts of water were each taken and mixed and stirred to obtain a thermosensitive color forming liquid for low temperature use. On the other hand, 1 dispersion C
10 parts 070 parts of the dispersion and 20 parts of water were each taken and mixed and stirred to obtain a thermosensitive coloring layer forming liquid for high temperature coloring.

Further, a decolorizing agent layer forming liquid for forming a decolorizing agent layer was prepared at the following ratio.

[Decolorizer layer forming liquid]

4.4-dithiodimorpholine 20 parts l
0% polyvinyl alcohol aqueous solution 201 water
6
o Next, on commercially available high-quality paper with a basis weight of approximately 52 g/-, the high-temperature coloring layer forming liquid was applied and dried to form a high-temperature coloring layer, with a drying weight of 5.0g1r+. The decolorizing layer forming liquid was applied on top with a dry adhesion amount of 5.0 g/rrr.
It was coated and dried to form a decolorizing layer. The low-temperature coloring layer forming liquid was applied thereon and dried to form a low-temperature coloring layer with a dry adhesion amount of 3.5 g/i.Next, a calender treatment was performed to obtain a smoothness of 500-1500 seconds. 1. A two-color heat-sensitive recording material of the present invention was obtained.

Example 2 [Liquid F] Na-di-peptyl-sulfosuccinate 5 parts water
95 A two-color heat-sensitive recording material of the present invention was obtained in the same manner as in Example 1, except that the liquid E in the low-temperature color forming layer forming liquid was changed to liquid F.

Example 3 [Liquid G] Na-di-nonyl-sulfosuccinate 5 parts water
A two-color heat-sensitive recording material of the present invention was obtained in the same manner as in Example 1 except that the liquid E in the low-temperature color forming layer forming liquid of Example 1 was changed to liquid G.

Example 4 [Liquid H] Liquid E 1 Water
39 The present invention was prepared in the same manner as in Example 1, except that liquid H was applied as an intermediate layer between the decoloring layer and the low-temperature coloring layer in Example 1 so that the drying amount was 1.5 g/rrr. A two-color heat-sensitive recording material was obtained.

Comparative Example 1 A comparative two-color heat-sensitive recording material was obtained in the same manner as in Example 1, except that the liquid E in the low-temperature color forming layer forming liquid of Example I was omitted.

Comparative Example 2 A comparative two-color heat-sensitive recording material was obtained in the same manner as in Example 2, except that the E solution in the H solution and the E solution in the low-temperature color forming layer forming solution in Example 2 were omitted.

The two-color heat-sensitive recording materials of Examples and Comparative Examples obtained as described above were tested for dynamic color development and matching using a G-1[1 facsimile test machine.The results are shown in Table 1 below.

The test machine was an 8 dot l manufactured by Kenko Electronic Parts Co., Ltd.
■It has a thermal head and the resistance of one heating element is approximately 400Ωl.
The color development test was performed at a main scanning recording speed of 20g.
The test was carried out under the following conditions: tsec/1ine, sub-scanning of 3.85 Q/am, platen suppression of 3.0 kg/cd, and head input of 0.61/dot.

A Macbeth densitometer (RD-514, Filtration 106 black color, 11-58 red color) was used for density measurement.

Note that 0 in Table 1. Δ and × are respectively “good”.

Means "slightly bad" and "bad."

Table-1 [Effects] As seen from Table-1, the two-color heat-sensitive recording material of the present invention has the following effects:
It can be seen that by incorporating a succinic acid surfactant, particularly Na-di-alkyl sulfosuccinate, in the low-temperature coloring layer, the low-temperature and high-temperature coloring layers have excellent uniform coloring properties and excellent two-color separation.

Claims (1)

[Claims] (1) 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, characterized in that the low-temperature coloring layer contains a succinic acid surfactant. Two-color heat-sensitive recording material.