JPH0651423B2 - Two-color thermal recording material - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a two-color heat-sensitive recording material, and more specifically, a normally colorless or slightly pale leuco dye and a developer that reacts with the leuco dye to form a color when heated. The present invention relates to a two-color thermosensitive recording material in which thermosensitive color developing layers containing as a main component are laminated.

[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, the color (display color) of that part can be recorded differently from the color of other parts in order to more clearly display the necessary data and numbers, depending on the recording application. The desirability 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. On the other hand, in the case of the latter multicolor color thermosensitive recording paper, the combination of color tone can be freely selected, but at the time of high temperature color development, higher aliphatic alcohol, polyether, as a decoloring agent for decoloring the low temperature color development layer, Polyethylene glycol derivatives, acetamide, stearamide, phthalonitrile as nitrogen-containing organic compounds, guanidine derivatives as amine derivatives, morpholine derivatives and the like are used. However, in such a multi-color recording material, it has now been found that the image on which the low temperature color developing layer is colored tends to be erased due to the influence of the decoloring agent layer over time.

〔Purpose〕

INDUSTRIAL APPLICABILITY With the present invention, it is possible to obtain a low temperature color development of a blackish color,
It is an object of the present invention to provide a two-color recording material which can obtain clear high-temperature color development without color mixing and which does not cause color images to be erased over time.

〔Constitution〕

According to the present invention, in a two-color thermosensitive recording material in which a high temperature color-developing layer, a color erasing layer and a low temperature color-developing layer are sequentially laminated on a support, a relatively high softening property is provided between the high temperature color-developing layer and the color erasing layer. A first intermediate layer containing a film-forming polymer binder as a main component is provided, and a film-forming polymer binder having a relatively low softening point is mainly provided between the decoloring layer and the low-temperature color-developing layer. A two-color heat-sensitive recording material is provided which is provided with a second intermediate layer as a component.

In the present invention, by providing the first intermediate layer having a relatively high softening point between the high temperature color developing layer and the color erasing layer, the influence of the decoloring agent on the high temperature color developing layer at the time of high temperature color formation is reduced. Further, by providing the second intermediate layer having a relatively low softening point between the low temperature color developing layer and the color erasing layer, the influence of the color erasing agent on the low temperature color developing image can be prevented and the high temperature color developing can be prevented. The decolorizing action of the decolorizing agent on the low-temperature color developing layer is not inhibited. Therefore, the two-color thermosensitive recording material according to the present invention has a high color density of the high temperature color developing layer, high color separation between high temperature color development and low temperature color development, and high storage stability of the low temperature color development image.

The film-forming polymer binder having a relatively high softening point contained in the first intermediate layer has a softening point of preferably 100 ° C or higher, more preferably 100 ° C to 200 ° C. Examples of such a binder include polyvinyl alcohol, polyurethane, hydroxyethyl cellulose, carboxymethyl cellulose, starch and derivatives thereof, but the present invention is not limited thereto. On the other hand, the film-forming polymer binder having a relatively low softening point contained in the second intermediate layer preferably has a softening point of 100 ° C. or lower, more preferably 40 to 1
Needless to say, the temperature is 00 ° C., which is lower than the softening point of the binder of the first intermediate layer in this case.

As such a binder having a relatively low softening point, for example,
Polyvinylidene chloride, styrene / butadiene copolymer,
Examples thereof include vinyl chloride / vinyl acetate copolymers and styrene / butadiene / acrylic copolymers, but the present invention is not limited thereto.

The first and second intermediate layers contain the binder as described above as a main component, but a heat-fusible substance (such as a sensitizer) or a filler may be contained in each intermediate layer.

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, pyroganol, phloroglucin, phloroglicin 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, benzine p-hydroxybenzoate, p-hydroxybenzyl benzyl p-hydroxybenzoate,
p-Hydroxybenzoic acid-o-chlorobenzyl, p-hydroxybenzoic acid-p-methylbedyl, 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-
In addition to 4'-chlorodiphenyl sulfone, bis (4-hydroxyphenyl) sulphide, etc., a guanidine organic base developer as shown below can also be 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, and 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-methyl- -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, benzoylleuco methylene 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. Further, in the high temperature color forming layer, an acylated lactone or sultone type acidic leuco dye as described below can be used in combination with the above-mentioned guanidine-based developer.

In the present invention, the combination of coloring colors can be freely selected, but the coloring of the low temperature coloring layer must be prevented during high temperature coloring. Physical properties required for such a decoloring agent are basic, poorly soluble in water,
It has a melting point of at least 80 ° C, is stable to air or heat, and has low toxicity. Examples of such a decoloring agent include the following.

(A) a piperazine derivative represented by the following general formula (I), (II) or (IV), (b) a disubstituted amide compound of a divalent carboxylic acid represented by the following general formula (III), and (c) a molecule A compound having 3 or more amide groups therein, or having 2 or more amide groups and one or more tertiary amine groups. General formula (I): General formula (II): General formula (III): General formula (IV): R in the general formulas (I), (II), (III) and (IV)
₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉
And R ₁₀ is optionally substituted alkyl, cycloalkyl, aryl or aralkyl, and R ₅ and R
The ends of ₆ and R ₇ and R ₈ may be bonded to each other to form a cyclic structure. A represents a divalent aliphatic group or aromatic group, X, X ₁ and X ₂ are carbonyl or sulfonyl, and Y ₁ and Y ₂ are alkylene. R
_The alkyl represented by _{1 to} R ₁₀ 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 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. Further, the piperazine ring in the general formulas (I), (II) and (IV) also has one substituent such as alkyl, aryl, halogen, alkoxy, aryloxy, acyl, acyloxy, alkoxycarbonyl, carbamoyl and acylamino. Two or more may be combined.

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-cytearyl-N'-benzoylpiperazine, N-phenyl-N'-benzoylpiperazine, N-benzyl-N'-benzoylpiperazine , N-phenyl-N'-cyclohexyloylpiperazine, N-phenyl-N'-acetylpiperazine, N-phenyl-N'-lauroylpiperazine, N-phenyl-N'-p-methylbenzoylpiperazine, N-phenyl- N'-p-chlorobenzoi Piperazine, N-benzoylaminoethyl-N'-benzoylpiperazine, N-benzoylaminopropyl-N'-benzoylpiperazine, N-benzoylaminobutyl-N'-benzoylpiperazine, N-benzoylaminopropyl-N'-cyclohexylpiperazine, N-cyclohexyloylaminopropyl-N'-cyclohexyloylpiperazine, N-benzoylaminoamyl-N'benzoylpiperazine, N- (p-chlorobenzoylaminoamyl) -N'-
(Chlorobenzoyl) piperazine, N-phenyl-N'-benzenesulfonylpiperazine, N-benzyl-N'-benzenesulfonylpiperazine, N-methyl-N'-benzenesulfonylpiperazine, N-propyl-N'-benzenesulfonylpiperazine, N-butyl-N'-benzenesulfonylpiperazine, N-hexyl-N'-benzenesulfonylpiperazine, N-cyclohexyl-N'-benzenesulfonylpiperazine, piperazine, N-lauryl-N'-benzenesulfonylpiperazine, N-stearyl- N'-benzenesulfonylpiperazine, N-phenyl-N'-butylsulfonylpiperazine, N-phenyl-N'-laurylsulfonylpiperazine, N-phenyl-N'-stearinsulfonylpiperazine, N-fe L-N'-cyclohexylsulfonylpiperazine, N-phenyl-N'-benzylsulfonylpiperazine, N-phenyl-N '-(p-methylbenzenesulfonyl) piperazine, N-butyl-N'-(p-methylbenzenesulfonyl) Piperazine, N-stearoylaminopropyl-N'-benzoylpiperazine, N-stearoylaminopropyl-N'-benzenesulfonylpiperazine 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-benzoylaminopropyl-N'-benzenesulfonylpiperazine, N-benzoylaminopropyl-N'-p-methylbenzenesulfonylpiperazine, N-benzoylaminoethyl-N'-benzenesulfonylpiperazine , N-benzoylaminobutyl-N'-benzenesulfonylpiperazine, N-benzoylaminopropyl-N'-butanesulfonylpiperazine, N-naphthoylaminopropyl-N'-benzenesulfonylpiperazine, N-benzenesulfonylaminop Pyr-N′-benzenesulfonylpiperazine, N-butyroylaminopropyl-N′-benzoylpiperazine, N-hexyloylaminopropyl-N′-benzoylpiperazine, N-lauroylaminopropyl-N′-benzoi 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, N-butylsulfonyl-N'-benzenesulfonylpiperazine, N-octylsulfonyl -N'-benzenesulfonylpiperazine, N- ( -Chlorobenzenesulfonyl) -N'-benzenesulfonylpiperazine, N-lauroyl-N'-benzenesulfonylpiperazine, N-lauroyl-N '-(p-methylbenzenesulfonyl) piperazine, N-benzoyl-N'-benzenesulfonylpiperazine, N- (o-chlorobenzoyl) -N'-benzenesulfonylpiperazine, N- (o-methylbenzoyl) -N'-benzenesulfonylpiperazine, 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 ( Clohexyloyl) 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 (2-phenoxypropionyl) piperazine, N, N'-bis (m-chlorobenzoyl) piperazine, N, N'-bis (o-chlorobenzoyl) piperazine, N, N'-bis (p-methylbenzoyl) Piperazine, N, N'-bis (m-methylbenzoyl) piperazine, N, N'-bis (o-methylbenzoyl) piperazine, N, N-bis (o-acetylo Cibenzoyl) piperazine, N, N'-bis (o-butyryloxybenzoyl) piperazine, N, N'-bis (p-phenylbenzoyl) piperazine, N, N'-bis (p-methoxycarbonylbenzoyl) piperazine, N , N'-bis (p-isopropoxycarbonylbenzoyl) piperazine, N, N'-bis (p-octadecylcarbamoylbenzoyl) piperazine and the like.

In the general formula (III), R ₅ , R ₆ , R ₇ and R ₈ represent a substituted or unsubstituted alkyl, cycloalkyl, aryl or aralkyl, and R ₅ and R ₆ or R ₇ and R
₈ can also be bonded at their ends to form a ring. Examples of the alkyl usually include straight or branched ones having 4 to 18 carbon atoms, examples of cycloalkyl include cyclohexyl, and examples of aryl include:
Examples thereof include phenyl, tolyl, xylyl, and the like, and examples of the aralkyl include benzyl, 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 an aliphatic 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, It is an arylene such as xylylene, and in this case, examples of the substituent include the above-mentioned 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'-tetraphenyl adipic acid diamide, N, N, N ', N'-tetra-p-butylphenyl adipic 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'-dicyclohexyl-N, N'-dimethylglutaric acid diamide, N, N'-dicyclohexyl-N, N'-dimethyladipic acid diamide, N, N, N ', ′ -Tetracyclohexyl adipic acid diamide, N, N′-dimethyl-N, N′-dicyclohexyl suberic acid diamide, N, N′-dimethyl-N, N′-dicyclohexyl sebacic acid diamide, N, N′-dimethyl-N , N'-dicyclohexylmalonic acid diamide, N, N, N ', N'-tetrabenzyladipic acid diamide, adipoyldipiperidine, adipoyldipipecoline, adipoyl-di-ε-caprolactam, adipoyldi-pyrrolidone, adipo Ildipiperidone, sebacoyl di-ε-caprolactam, cepacoyl di-piperidone, adipoyl-di-3-chloro-ε-caprolactam, succinyl-di-3-chloro-ε-caprolactam and the like.

N, N'-terephthaloylbispiperidine, N, N'-isophthaloylbispiperidine, N, N'-phthaloylbispiperidine, N, N'-terephthaloylbismorpholine, N, N'-isophthale Roylbismorpholine, N, N'-phthaloylbismorpholine, N, N'-terephthaloylbis-4-methylpiperazine, N, N'-isophthaloylbis-4-methylpiperazine, N, N'-phthaloylbis -4-methylpiperazine, N, N'-terephthaloylbis-4-phenynylpiperazine, N, N'-isophthaloylbis-4-phenylpiperazine, N, N'-phthaloylbis-4-phenylpiperazine, N , N'-terephthaloylbis-4-propylpiperazine, N, N'-isophthaloylbis-4-propylpiperazine, N, N'-phthaloyl-4-propylpiperazine, N, N'-terephthalloy Biscaprolactam, N, N'-isophthaloylbiscaprolactam, N, N'-phthaloylbiscaprolactam, N, N'-terephthaloylbis-3-chlorocaprolactam, N, N'-isophthaloylbis-3 -Chlorocaprolactam, N, N'-phthaloylbis-3-chlorocaprolactam, N, N'-terephthalolbisvalerolactam, N, N'-isophthaloylbisvalerolactam, N, N'-phthaloylbisvalerolactam , N, N'-terephthaloylbispyrrolidine, N, N'-isophthaloylbispyrrolidine, N, N'-phthaloylbispyrrolidine, N, N'-terephthaloylbis-diethylamine, N, N'- Isophthaloylbis-diethylamine, N, N'-phthaloylbis-diethylamine, N, N'-terephthaloylbis-dipropylamine, N, N'-isophthaloylbi -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-amine, N, N'-terephthaloylbis-dibenzylamine , N, N'-isophthaloylbis-dibenzylamine, N, N'-terephthaloylbis-dioctylamine, N, N'-isophthaloylbis-dioctylamine, N, N'-terephthaloylbis -Diethoxypropylamine, N, N'-terephthaloylbis-4-chlorobutylamine, N, N'-terephthaloylbis-dibenzoylaminoethylamine, N, N ' -Isophthaloylbis-dibenzoylaminoethylamine, N, N'terephthaloylbis-benzoylaminopropylamine, N, N'-isophthaloylbis-benzoylaminopropylamine, N, N'-terephthaloylbis- Diacetylaminoethylamine, N, N'-isophthaloylbis-diacetylaminoethylamine, N, N'-terephthaloylbis (4-methylpiperidine), N, N'-terephthaloylbis (3-methylpiperidine), N, N'-terephthaloylbis (3,5-dimethylpiperidine), N, N'-terephthaloylbis (2-methylpiperidine), N, N'-terephthaloylbis (2,6-dimethylpiperidine) ), N, N′-isophthaloylbis (4-methylpiperidine), N, N′-phthaloylbis (4-methylpiperidine), N, N′-isophthaloylbis 3-methylpiperidine), N, N'-phthaloylbis (3-methylpiperidine), N, N'-isophthaloylbis (3,5-dimethylpiperidine), N, N'-phthaloylbis (3,5-dimethylpiperidine) ), N, N′-isophthaloylbis (2-methylpiperidine), N, N′-phthaloylbis (2-methylpiperidine), N, N′-isophthaloylbis (2,6-dimethylpiperidine), N , N'-phthaloylbis (2,6-dimethylpiperidine), N, N'-terephthaloylbis (4-benzylpiperidine), N, N'-isophthaloylbis (4-benzylpiperidine), N, N ' -Phthaloylbis (4-benzylpiperidine), N, N'-terephthaloylbis (4-methoxycarbonylpiperidine), N, N'-isophthaloylbis (4-methoxycarbonylpiperidine), N, N'-terephthalate Ilbis (2-methoxycarbonylpiperidine), N, N'-isophthaloylbis (2-methoxycarbonylpiperidine), N, N'-phthaloylbis (2-methoxycarbonylpiperidine), N, N'-terephthaloylbis ( 4-ethylpiperidine), N, N'-terephthaloylbis (4-propylpiperidine), N, N'-terephthaloylbis (4-butylpiperidine), N, N'-isophthaloylbis (4- Ethylpiperidine), N, N'-isophthaloylbis (4-normalpropylpiperidine), N, N'-isophthaloylbis (4-butylpiperidine), N, N'-isophthaloylbis (4-butyl) Piperidine), N, N'-phthaloylbis (4-ethylpiperidine), N, N'-phthaloylbis (4-propylpiperidine), N, N'-phthaloylbis (4-butylpiperine) Lysine), N, N'-terephthaloylbis (3-hydroxymethylpiperidine), N, N'-isophthaloylbis (3-hydroxymethylpiperidine), N, N'-phthaloylbis (3-hydroxymethylpiperidine) , N, N'-terephthaloylbis (5-ethyl-2-methylpiperidine), N, N'-isophthaloylbis (5-ethyl-2-methylpiperidine), N, N'-phthaloylbis (5- Ethyl-2-methylpiperidine), N, N'-terephthaloylbis (N-ethyl-N'-cyclohexylamine), N, N'-isophthaloylbis (N-ethyl-N'-cyclohexylamine), N, N'-phthaloylbis (N-ethyl-N'-cyclohexylamine), N, N'-terephthaloylbis (N-propyl-N'-cyclohexylamine), N, N'-isophthaloyl Scan (N- propyl -N'- cyclohexylamine), N, N'Futaroirubisu (N-
Propyl-N'-cyclohexylamine), N, N'-terephthaloylbis (N-butyl-N'-cyclohexylamine), N, N'-isophthaloylbis (N-butyl-N'-cyclohexylamine) , N, N'-phthaloylbis (N-butyl-N'-cyclohexylamik), N, N'-terephthaloylbis (4-ethyloxymethylpiperidine), N, N'-isophthaloylbis (4- Ethyloxymethylpiperidine), N, N'-terephthaloylbis (4-ethyloxyethylpiperidine), N, N'-isophthaloylbis (4-ethyloxyethylpiperidine), N, N'-terephthalloy Rubis (2-methoxyethylpiperidine), N, N'-isophthaloylbis (2-methoxyethylpiperidine), N, N'-terephthaloylbis (4-methoxyethylpiperidine), N, N ' (Isophthaloylbis (4-methoxyethylpiperidine), N, N'-terephthaloylbis (4-phenylpiperidine), N, N'-isophthaloylbis (4-phenylpiperidine), N, N'- Phthaloylbis (4-phenylpiperidine), N, N'-terephthaloylbis (4-phenylpropylpiperidine), N, N'-isophthaloylbis (4-phenylpropylpiperidine), N, N'-phthaloylbis (4 -Phenylpropylpiperidine) and the like.

In the general formula (IV), R ₉ and R ₁₀ represent alkyl, cycloalkyl, aryl or aralkyl which may have a substituent. Examples of the alkyl usually include linear or branched ones having 1 to 18 carbon atoms, examples of cycloalkyl include cyclohexyl, examples of aryl include phenyl, tolyl, xylyl and the like,
Examples of aralkyl include benzyl and phenethyl. 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 linear or branched alkylene groups having 1 to 18 carbon atoms.

Specific examples of the compound represented by the general formula (IV) 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- (Chlorobenzoylaminoamyl) -N'-benzoylaminopropylpiperazine, N-cyclohexyloylaminopropyl-N'-cyclohexyloylaminobutylpiperazine, N-naphthoylaminopropyl-N'-benzoylaminopropylpiperazine, N-butyl Royl Aminop Ropyl-N'-benzoylaminopropylpiperazine, N-lauroylaminopropyl-N'-benzoylaminopropylpiperazine, N-stearoylaminopropyl-N'-benzoylaminopropylpiperazine, N-butyroylaminopropyl-N'-cyclohexyl Ilaminobutylpiperazine, N-naphthoylaminopropyl-N′-lauroylaminopropylpiperazine, N-naphthoylaminopropyl-N′-stearoylaminopropylpiperazine and the like.

Specific examples of the compound having 3 or more amino groups in the molecule or having 2 or more amide groups 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-diethylenetriamine, 1,7-di-α-naphthoyl-4-cyclohexyl -Diethylenetriamine, N, N ', N "-tripivaloyl-diethylenetriamine, N, N', N", N-tetraacetyl-triethylenetetramine, N, N'N ", N-tetracyclohexyloyl-triethylenetetramine, Ethylenediamine tetraacetic acid tetraanilide, Ethylenediamine tetraacetic acid tetracyclohexylamide, Ethylenediamine tetraacetic acid Acid tetra-2-ethylhexylamide, ethylenediaminetetraacetic acid tetralaurylamide, ethylenediaminetetraacetic acid tetrastearylamide, ethylenediaminetetraacetic acid tetrapiperidide, ethylenediaminetetraacetic acid tetra-ε-caprolactamide and the like.

In addition, as a decolorizing agent, polyether, polyethylene glycol derivative, solid alcohol, guanidine derivative,
A morpholine derivative or the like can be used.

The decoloring agent used in the present invention is used alone or in the form of a mixture of two or more kinds, and these are usually white and fixed stably in the air, and in the case of the present invention, 80 ° C. or higher, preferably Those having a melting point in the range of 120 to 250 ° C. are preferably used.

In the present invention, in order to bond and support the high-temperature and low-temperature color-forming layers comprising the leuco dye and the color-developing agent and the decolorizing layer comprising the decoloring agent on the support, various conventional binders can be appropriately used. , For example, polyvinyl alcohol,
Starch and its derivatives, methoxycellulose, hydroxyethyl cellulose, carboxymethyl cellulose,
Cellulose derivatives such as methylcellulose and ethylcellulose, 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, poly In addition to water-soluble polymers such as acrylamide, sodium alginate, gelatin, and casein, polyvinyl acetate,
Polyurethane, styrene / butadiene copolymer, polyacrylic acid, polyacrylic acid ester, vinyl chloride / vinyl acetate copolymer, polybutylmethacrylate, ethylene / vinyl acetate copolymer, styrene / butadiene / acrylic copolymer, etc. Latex can be used.

Further, in the present invention, together with the leuco dye and the color developer, if necessary, further auxiliary additives commonly used in this type of heat-sensitive recording material, for example, a filler, a surfactant, a heat-fusible substance ( Alternatively, a lubricant) or the like can be used in combination. In this case, as the filler, for example, calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, inorganic fine powder such as surface-treated calcium or silica, etc. , Urea-formalin resin, styrene / methacrylic acid copolymer, polystyrene resin, and other organic fine powders,
Examples of heat-fusible substances include higher fatty acids or their esters, amides or metal salts, as well as various waxes,
50-200 ° C for condensates of aromatic carboxylic acids and amines, benzoic acid phenyl esters, higher linear glycols, 3,4-epoxy-dialkyl hexahydrophthalates, higher ketones, other heat-fusible organic compounds, etc. Some of them have a melting point of some extent.

〔Example〕

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% hydroxyethyl cellulose aqueous solution 20〃 water 60〃 [dispersion liquid-B] 3,3-dichloropheniothio 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% Hydroxyethyl cellulose 15 〃 Water 65 〃 Dispersion A 10 parts prepared as above, Dispersion B 70 parts, water
20 parts of each was mixed and stirred to obtain a low temperature heat-sensitive color forming solution. On the other hand, 10 parts of Dispersion C, 70 parts of Dispersion D and 20 parts of water were respectively taken and mixed and stirred to obtain a thermosensitive color forming layer forming liquid for high temperature color forming.

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

[Decolorant layer forming liquid]

4,4-dithiodimorpholine 20 parts 10% aqueous solution of polyvinyl alcohol 20〃 water 60〃 Next, the high-temperature color-forming layer-forming liquid has a dry coating amount of 5g on a commercially available high-quality paper weighing about 52g / m ^2. / M ² to obtain a high-temperature color-developing layer, and a polyvinyl alcohol (solid content 8%) aqueous solution is applied on the high-temperature color-developing layer at a dry amount of 2 g / m ^2.
The first intermediate layer is formed by coating and drying so that the coating amount becomes m ^2, and then the decolorizing agent layer forming liquid has a dry adhesion amount of 3.5 g / m ²
Coating dried to form a decolorizing layer such that the further second and over a polyvinylidene chloride latex (45% solids) dry coating weight was applied and dried so that 1.5 g / m ² that Was formed, and finally, the low-temperature color-forming layer-forming liquid was applied and dried so as to have a dry adhesion amount of 3.5 g / m ² to form a low-temperature color-forming layer. Then, a calendering treatment was performed so that the smoothness was 500 to 1500 sec to obtain a two-color thermosensitive recording material of the present invention.

Example 2 In the above example, instead of the polyvinyl alcohol used for forming the first intermediate layer, a solvent solution of hydroxyethyl cellulose (solid content 10%) was used, and the polychlorination used for forming the second intermediate layer was used. A two-color heat-sensitive recording material of the present invention was obtained in the same manner as in Example 1 except that a styrene / butadiene copolymer (solid content: 47.5%) was used instead of the vinylidene latex.

Comparative Example 1 A two-color heat-sensitive material for comparison was prepared in the same manner as in Example 1 except that the same polyvinylidene chloride latex as in the second intermediate layer was used instead of the polyvinyl alcohol used as the first intermediate layer in Example 1. A recording material was obtained.

Comparative Example 2 A two-color thermosensitive recording material for comparison was obtained in the same manner as in Example 1 except that the first and second intermediate layers were not formed.

Table 1 below shows the results of testing the two-color thermosensitive recording materials of the present invention and comparative examples obtained as described above with respect to the dynamic color forming property and the time-dependent change of the color formed image with a G-III fax limiter tester.

The test machine is 8 dots / mm from Matsushita Electronic Components Co., Ltd.
It has a thermal head, the resistance of the heating element is about 400Ω / dot, and the color development test is a main scanning recording speed of 20msec / li.
Ne, sub-scan 3.85 l / mm, platen pressure 3.0 kg / cm ² , head input 0.6 W / dot.

For the density measurement, a Macbeth densitometer (RD-514, filter W-106 black color development, W-58 red color development) was used.

[Effect] As can be seen from Table 1, the two-color thermosensitive recording material of the present invention can obtain black color at low temperature color development and red color at high temperature color development with high density and good color separation, and at the same time, low temperature color image obtained. Is
The stability over time is remarkably improved.

Claims (2)

[Claims] 1. A two-color heat-sensitive recording material comprising a support, on which a high-temperature color-developing layer, a decoloring layer and a low-temperature color-developing layer are sequentially laminated, and a relatively high softening point between the high-temperature color-developing layer and the decolorization layer. The first intermediate layer containing the film-forming polymer binder as a main component is provided, and the film-forming polymer binder having a relatively low softening point as a main component is provided between the decoloring layer and the low-temperature color-developing layer. A two-color heat-sensitive recording material comprising a second intermediate layer having: 2. The softening point of the binder of the first intermediate layer is 100.
℃ or more, the softening point of the binder of the second intermediate layer is the first
The two-color heat-sensitive recording material according to claim 1, which is lower than the softening point of the binder in the intermediate layer and is 100 ° C. or lower.