JPH0780354B2 - Two-color thermal recording material - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a two-color thermosensitive recording material, and more specifically, a thermosensitive coloring layer having different coloring heat energies and different coloring tones is successively formed on a support. And a two-color thermosensitive recording material.

[Prior art]

The heat-sensitive recording material is one in which a heat-sensitive color forming layer capable of forming a color-formed 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. As such a conventional heat-sensitive recording material, a lactone ring, a lactam ring,
A colorless or light-colored leuco dye having a spiropyran ring (main coloring agent) and a developer that develops a color by reacting with this leuco dye when heated (coloring auxiliary agent) have a clear color tone and have a fogging effect. It is often used because it has few phenomena.

By the way, the thermosensitive recording material is not only used for copying books, documents, etc., because a colored image can be easily obtained only by heating it, but it is also used in various fields such as electronic calculators, facsimiles, telexes, etc. Depending on the recording application, it is desirable to be able to record the color of that part (display color) by changing it from the color of other parts, in order to display the necessary data and numbers more clearly depending on the purpose of recording. It is natural.

Recently, attempts have been made to obtain multicolor recording by utilizing the difference in heating temperature or the difference in thermal energy, and various multicolor color thermosensitive recording papers have been proposed accordingly. The multicolor color thermosensitive recording paper is generally formed by stacking two kinds of high-temperature and low-temperature color-developing layers, which are colored in different colors with different color-developing heat energies, on a support. It is divided into types. One is to obtain a color tone different from the color tone of the low temperature color layer by mixing with the color tone of the low temperature color layer when the high temperature color layer is colored, and the other is to color the high temperature color layer. In this case, a color erasing agent for erasing the low temperature color developing layer is used to obtain only the color developing color tone of the high temperature color developing layer without color mixture of the color developing color tone of the low temperature color developing layer. As specific examples of these, the former ones include Japanese Patent Publication No. Sho 49-69, Japanese Patent Publication No. Sho 49-4342, Japanese Patent Publication No. Sho 49-27708, and Japanese Patent Laid-Open Publication No. Sho 48-86543.
Japanese Patent Publication No. Sho 49-65239 and the like, and the latter ones are disclosed in Japanese Patent Publication No. 50-17865 and Japanese Patent Publication No. 50-17866.
JP-B No. 51-29024, JP-B No. 51-87542, JP-A No. 50-18048, and JP-B No. 55-36519.

However, in the case of the former multicolor thermosensitive recording paper,
In the case of high-temperature color development, the color tone that can be specifically realized to mix with the color tone of the low-temperature color layer is such that the high-temperature color tone such as red-black, blue-black, etc. is limited to a black type with a strong tone. There is. Therefore, the latter method is preferable as the two-color thermosensitive recording material, and the basic color of a black color can be used for the low-temperature color-developing layer, and the high-temperature color-developing layer obtains a color-developing color tone such as red and blue by a conventionally known method. be able to. However, in the high-temperature color-developing layer obtained by the conventional method, particularly in the red-color-developing system, there is a problem that the heat-sensitive color-developing layer-forming liquid is liable to be fogged and the background fog is generated even after laminating to impair the appearance.

〔Purpose〕

An object of the present invention is to provide a two-color heat-sensitive recording material which can obtain a black-colored low-temperature color-developing layer, can obtain a clear high-temperature color development without color mixture, and is excellent in contrast with less background fog. .

〔Constitution〕

According to the present invention, in a two-color thermosensitive recording material in which a high-temperature color-developing layer, a decoloring layer and a low-temperature color-developing layer are laminated in this order on a support,
There is provided a two-color heat-sensitive recording material characterized in that the high-temperature color-forming layer contains a color pigment having a complementary color relationship with the color tone of the high-temperature color-forming layer.

As the color pigment used in the high temperature color forming layer in the present invention,
It is a coloring pigment having a complementary color relationship to the coloring color tone of the high temperature color forming layer, and the color tone of the pigment used is different depending on the coloring color tone and is not particularly limited, but examples of usable coloring pigments include monoazo pigment, Diazo pigment, polyazo pigment, quinacridone, dioxazine violet, polychlorobromophthalocyanine green, phthalocyanine green, phthalocyanine blue,
Examples include yellow, red, green, and blue color pigments obtained from iron oxide red, chrome yellow, chrome oxide green, ultramarine blue, titanium dioxide, and the like.

In the present invention, examples of the color developer contained in the high temperature color forming layer and the low temperature color forming layer include N, N′-diphenylthiourea, Np-ethylphenyl-N′-phenylthiourea and Np-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'-isopropylidene diphenol, 4,4'-isopropylidene bis (2-chlorophenol), 4,4'-isopropylidene bis (2,6-
Dibromophenol), 4,4'-isopropylidenebis (2,6-dichlorophenol), 4,4'-isopropylidenebis (2-methylphenol), 4,4'-isopropylidenebis (2-tert-butylphenol) ), 4,4′-s
Ec-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 phenolic resin, 2,2'-thiobis (4,6-dichlorophenol), catechol, resorcin, hydroquinone, viloganol, phloroglucin, phloroglycine carvone 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-hydroxybenzyl p-hydroxybenzoate,
p-hydroxybenzoic acid-o-chlorobenzyl, p-hydroxybenzoic acid-p-methylbenzyl, p-hydroxybenzoic acid-n-octylbenzoic acid, zinc salicylate,
1-hydroxy-2-naphthoic acid, 2-hydroxy-6
-Naphthoic acid, zinc 2-hydroxy-6-naphthoate,
4-hydroxydiphenyl sulfone, 4-hydroxy-
4'-chlorodiphenyl sulfone, bis (4-hydroxyphenyl) sulfide, etc. are used.

The leuco dyes used in the present invention may be used alone or as a mixture of two or more, and as such leuco dyes,
What is applied to this type of heat-sensitive material is arbitrarily applied, for example, leuco compounds of dyes such as triphenylmethane-based, fluoran-based, phenothiazine-based, auramine-based, spiropyran-based, indolinophtalide-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 letolactone), 3,3-bis ( p-Dimethylaminophenyl) -6-diethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide, 3,3-bis (p-dibutylaminophenyl) phthalide, 3-cyclohexyl Amino-6-chlorofluorane, 3-dimethylamino-5,7-dimethylfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7,8-benz Fluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3- (Np-tolyl-N-ethylamino) -6-ethyl- -Anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 2- {N- (3'-trifluoromethylphenyl) amino} -6-diethylaminofluorane, 2- {3, 6-bis (diethylamino) -9- (o-chloroanilino) xanthylbenzoic acid lactam}, 3-diethylamino-6-methyl-7- (m-trichloromethylanilino) fluorane, 3-diethylamino-7- (o-chloroanilino ) Fluoran, 3-dibutylamino-7- (o-chloroanilino) fluorane, 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-pyrrolispirane, 6'-bromo-3'-methoxy-benzoindolino-pyrrolispirane, 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-p-chlorophenyl) methylaminofluorane, 3-diethylamino-5-chloro-7- (α-phenylethylamino) fluorane, 3- (N-ethyl-p-toluidino) -7- (α-phenylethylamino) fluorane, 3-diethylamino-7- (o-methoxycarbonylphenylamino) fluorane, 3-diethylamino-5-methyl-7- ( α-phenylethylamino) fluorane, 3-diethylamino-7-piperidi Fluoran, 2-chloro-3-(N-Mechirutoruijino)-7-(p
-N-butylanilino) fluorane, 3- (N-benzyl-N-cyclohexylamino)-
5,6-benzo-7-α-naphthylamino-4′-bromofluorane, 3-diethylamino-6-methyl-7-mesitidino-
4 ', 5'-benzofluorane and the like.

In the present invention, specific examples of particularly preferable leuco dyes to be contained in the high temperature color forming layer include, for example, 3-diethylamino-7-chlorofluorane and 3-diethylamino-
6-methyl-7-chlorofluorane, 3-cyclohexylamino-6-chlorofluorane, 3-diethylaminobenzo [α] fluorane and the like can be mentioned.

As the decoloring agent used in the present invention, it is possible to use various conventionally known decoloring agents as shown in the above-mentioned description of the prior art. Formulas (I), (II), (II
Compounds represented by I), (IV) and (V), compounds having 3 or more amide groups in the molecule or having 2 or more amide groups and 1 or more tertiary amino groups, N , N ′
Preference is given to using dithiocaprolactam and the like.

General formula (I) General formula (II) General formula (III) General formula (IV) General formula (V) In the general formulas (I), (II) and (III), R ₁ and R ₂ each have an optionally substituted alkyl, cycloalkyl,
It is aryl or aralkyl and X is carbonyl or sulfonyl. Examples of the alkyl represented by R ₁ and R ₂ include a straight chain or branched chain having 1 to 18 carbon atoms, cycloalkyl includes cyclohexyl, and aryl includes phenyl and tolyl. , Xylyl and the like, and aralkyl includes benzyl, phenethyl and the like. These substituents may further have other substituents, and examples of such a substituent include, for example, alkyl, aryl, halogen, etc., as well as alkoxy, aryloxy, acyl, acyloxy, alkoxycarbonyl, carbamoyl, Acylamino and the like can be mentioned. In addition, general formulas (I) to (II
Also in the piperazine ring in I), alkyl, aryl,
One or more substituents such as halogen, alkoxy, aryloxy, acyl, acyloxy, alkoxycarbonyl, carbamoyl and acylamino may be bonded.

Specific examples of the compound represented by the general formula (I) include the followings.

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 and the like.

Specific examples of the compound represented by the general formula (II) include the followings.

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 (o-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 followings.

N, N'-bis (butyroyl) piperazine, N, N'-bis (hexyloyl) piperazine, N, N'-bis (n-octyloyl) piperazine, N, N'-bis (tertiary octyloyl) piperazine, N , N'-bis (lauryloyl) piperazine, N, N'-bis (stearoyl) piperazine, N, N'-bis (pivaloyl) piperazine, N, N'-bis (cyclohexyroyl) 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) piperazine, N, N'-bis (phenoxyacetyl) piperazine, N, N'-bis (p-chlorobenzoyl) piperazine, N, N'-bis ( - phenoxypropionic propionyloxy) piperazine.

In the general formula (IV), R ₁ , R ₂ , R ₃ and R ₄ represent substituted or unsubstituted alkyl, cycloalkyl, aryl or aralkyl, and R ₁ and R ₂ or R ₃ and R ₄ are The ends thereof may be bonded to each other to form a ring. Examples of the alkyl generally include straight or branched ones having 4 to 18 carbon atoms, examples of the cycloalkyl include cyclohexyl, examples of the aryl include phenyl, tolyl, xylyl, and the like. As alkyl, benzyl,
Examples include phenethyl and the like. These substituents may further have other substituents, and examples of such a substituent include alkyl, aryl, alkoxy, acyl, halogen, and the like, as well as acylamino and alkoxy such as benzoylamino, acetylamino and the like. Carbonyl, carbamoyl, aryloxy, aralkyloxy, 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 a substituted or unsubstituted alkylene having 1 to 8 carbon atoms, and in the case of an aromatic group, a substituted or unsubstituted phenylene, tolylene, xylylene. And the like, and in this case, examples of the substituent include halogen, acylamino, alkoxycarbonyl, carbamoyl, aryloxy, aralkyloxy and the like.

Specific examples of the di-substituted amide compound of the aliphatic and aromatic divalent carboxylic acids include the followings.

N, N, N'N'-tetrabutyl succinic acid diamide, N, N, N'N'-tetraoctyl succinic acid diamide, N, N, N'N'-tetralauryl succinic acid diamide, N, N, N 'N'-tetrastearyl succinic acid diamide, N, N, N'N'-tetraphenyladipic acid diamide, N, N, N'N'-tetra-p-butylphenyladipic acid diamide, N, N, N'N'-tetrabutyl adipic acid diamide, N, N, N'N'-tetraoctyl adipic acid diamide, N, N, N'N'-tetralauryl adipic acid diamide, N, N, N'N'-tetrastearyl Adipic acid diamide, N, N'-dicyclohexyl-N, N'-dimethylsuccinic acid diamide, N, N'-isophthaloylbispyrrolidine, N, N'-phthaloylbispyrrolidine, N, N'-terephthalloyd Rubis-diethylamine, N, N'-isophthaloylbis-diethyl Amine, N, N'-phthaloylbis-diethylamine, N, N'-terephthaloylbis-dipropylamine, N, N'-isophthaloylbis-dipropylamine, N, N'-terephthaloylbis-diamine Butylamine, N, N'-isophthaloylbis-dibutylamine, N, N'-terephthaloylbis-cyclohexyl-methylamine, N, N'-isophthaloylbiscyclohexyl-methylamine, N, N'-tere Phthaloylbis-dicyclohexyl-amine, N, N'-isophthaloylbis-dicyclohexyl-amine and the like.

In the general formula (V), R ₁ and R ₂ represent alkyl, cycloalkyl, aryl or aralkyl which may have a substituent. The alkyl usually has 1 carbon atom.
~ 18 straight chain or branched chain, cycloalkyl includes cyclohexyl, aryl includes phenyl, tolyl, xylyl, and the like, and aralkyl includes benzyl, phenethyl, and the like. To be These substituents may further have other substituents, and examples of such substituents include alkyl, aryl, halogen, alkoxy, aryloxy, aralkyloxy, acyl, acyloxy, alkoxycarbonyl, carbamoyl, Substituents such as acylamino may be mentioned. Y ₁ and Y ₂ are straight or branched chain carbon atoms 1 to 18
Is an alkylene group.

Specific examples of such compounds include the followings.

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 3 or more amino groups or 2 or more amide groups in the molecule and 1 or more tertiary amino groups include the followings.

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-di-α-naphthoyl-4- Cyclohexyl-diethylenetriamine, N, N ', N "-tripivaloyl-diethylenetriamine, N, N', N", N-tetraacetyl-triethylenetetramine, N, N ', N ", N-tetracyclohexyloyl-triethylene Tetramine etc.

In the present invention, in order to bind and support the leuco dye, the developer and the decolorizer on a support, various conventional binders can be appropriately used, and examples thereof include polyvinyl alcohol, starch and derivatives thereof. Methoxycellulose,
Cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, ethyl cellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylic acid amide / acrylic acid ester copolymer, acrylic acid amide / acrylic acid ester / methacrylic acid terpolymer, styrene / Maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, casein, and other water-soluble polymers, polyvinyl acetate, polyurethane, styrene / butadiene copolymer Combined, polyacrylic acid, polyacrylic ester, vinyl chloride /
A latex such as vinyl acetate copolymer, polybutyl methacrylate, ethylene / vinyl acetate copolymer, styrene / butadiene / acrylic copolymer can be used.

Further, in the present invention, an auxiliary additive component, such as a filler or a surfactant, which is commonly used in this type of heat-sensitive recording material, can be used in combination with the leuco dye and the color developer, if necessary. . In this case, as the filler, for example, calcium carbonate, silica, zinc oxide, titanium oxide,
Inorganic fine powders such as aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, surface-treated calcium and silica, as well as organic systems such as urea-holimarin resin, styrene / methacrylic acid copolymer, polystyrene resin The fine powder of Further, in the field of this kind, if necessary, a heat-fusible substance which is commonly used in this kind of field can be used, and in this case, as the heat-fusible substance,
For example, in addition to higher fatty acids or their esters, amides or metal salts, various waxes, condensates of aromatic carboxylic acids and amines, phenyl benzoates, higher linear glycols, 3,4-epoxy-hexahydrophthalic acid Dialkyl, higher ketones, other heat-fusible organic compounds, etc.
One having a melting point of about 50 to 200 ° C. can be mentioned.

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

EXAMPLES Next, the present invention will be described in more detail with reference to examples. The parts and% shown below are based on weight.

Example 1 The following components were each used in a sand mill to obtain an average particle size of 2 to
Dispersions A to D were prepared by pulverizing and dispersing so as to have a particle size of 3 μm.

[Dispersion-A]

3- (N-ethyl-N-amylamino) -6-methyl-7-anilinofluorane (black) 20 parts 10% aqueous solution of polyvinyl alcohol 20〃 water 60〃 [dispersion liquid-B] 3,3'-dichlorophenylthio Urea 10 parts Calcium carbonate 10〃 Polyvinyl alcohol (10% aqueous solution) 20〃 Water 60〃 [Dispersion-C] 3-Diethylamino-7-chlorofluorane (red) 20 parts 10% Hydroxyethyl cellulose aqueous solution 20〃 Water 60〃 [ Dispersion D] Bisphenol A 10 parts Calcium carbonate 10 〃 10% polyvinyl alcohol aqueous solution 20 〃 Water 60 〃 Dispersion A 10 parts, dispersion B 70 parts, water prepared as above
10 parts of each was taken and mixed and stirred to obtain a low temperature color forming layer forming liquid. On the other hand, 10 parts of Dispersion C, 70 parts of Dispersion D, 20 parts of water, and 0.008 parts of 20% phthalocyanine blue water dispersion were respectively mixed and stirred to obtain a high temperature color forming layer forming liquid.

Further, a decolorant layer forming liquid for forming a decolorant layer was prepared in the following ratio.

[Decolorant layer forming liquid]

4,4 dithio dimorpholine 20 parts of a 10% aqueous solution of polyvinyl alcohol 20〃 water 60〃 Next, on a commercial fine paper having a basis weight of about 52 g / m ^2, the hot color layer forming liquid (dry coating amount; 5g / m ² ), decolorizer layer forming liquid (dry coating amount; 2.5g / m ² ) and low temperature color forming layer forming liquid (dry coating amount; 3.5g / m ² ) are applied and dried, and then smoothed. 500 to 150 degrees
Calendering was performed for 0 sec to obtain a two-color heat-sensitive recording material of the present invention.

Comparative Example 1 A two-color thermosensitive recording material of Comparative Example 1 was obtained in the same manner as in Example 1 except that the phthalocyanine blue aqueous dispersion was removed from the high temperature color forming layer forming solution of Example 1.

With respect to the two-color thermosensitive recording materials of Examples and Comparative Examples obtained as described above, the dynamic color development characteristics and the color tone of the background portion were measured with a color difference meter using a G-III facsimile test machine. The results are shown in Table 1 below.

The color-developing tester has a thermal head of 8 dots / mm manufactured by Matsushita Electronic Components Co., Ltd., and the resistance of the heating element is about 400 Ω / d.
ot, the color development test is main scanning recording speed 20sec / line,
Sub-scan 3.85 / mm, Platen pressure 3.0 kg / cm ² , Head input
It was performed under the condition of 0.6 w / dot.

The densitometer is a Macbeth densitometer (RD-514 Filter W
-106 black color development and W-58 red color development) were used. The color difference meter
DICOM ND-504DE manufactured by Nippon Denshoku Industries Co., Ltd. was used.

[Effect] As can be seen from Table-1, the two-color thermosensitive recording material of the present invention has excellent two-color separation property, and by adjusting the background fog in the high-temperature color-developing layer with a coloring pigment, the appearance of the background without lowering the whiteness of the background. An excellent two-color heat-sensitive recording material can be obtained.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kenchi Kato 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References JP-A-56-40588 (JP, A) JP-A-SHO 60-68991 (JP, A) JP-A-59-155094 (JP, A)

Claims (1)

[Claims] 1. A two-color thermosensitive recording material comprising a support, on which a high-temperature color-developing layer, a decoloring layer, and a low-temperature color-developing layer are laminated in that order, in the high-temperature color-developing layer, there is a complementary color relation to the color tone of the high-temperature color-developing layer. A two-color heat-sensitive recording material containing a coloring pigment as follows.