JPH0811442A - Transfer sheet - Google Patents

Abstract

PURPOSE:To form a transfer sheet for black especially excellent in light fastness by providing a colorant layer containing specific dis-azo coloring matter, dicyanoimidazole-azo coloring matter and indoaniline coloring matter on a tissue like base material. CONSTITUTION:A transfer sheet is formed by providing a colorant layer containing dis-azo coloring matter represented by formula ( X<1>, X<2>, X<3> and X<4> are a hydrogen atom, an alkyl group, an alkoxy group or a hydroxyl group and Y<1>, Y<2>, Y<3>, Y<4>, Y<5> and Y<6> are a hydrogen atom, an alkyl group or an alkoxy group), dicyanoimidazole coloring matter and indoaniline coloring matter on a tissue like base material. When recording is performed by using this transfer sheet, high black density is achieved and recording near to an achromatic state is obtained. The compounding ratio of the respective coloring matters in the colorant layer is pref. set so that the dis-azo coloring matter represented by the general formula is 20-45wt.%, the dicyanoimidazole coloring matter is 10-30wt.% and the indoaniline coloring matter is 40-65wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer sheet used for color hard copy by a so-called thermal transfer recording system. In particular, it relates to a transfer sheet used in a sublimation transfer recording system.

[0002]

2. Description of the Related Art In recent years, a technique for converting a color image by an electric signal such as a video image into a color hard copy has been advanced, and for example, electrophotographic, ink jet, thermal transfer and the like are being studied. Of these,
In particular, the thermal transfer method is advantageous because the maintenance and operation of the apparatus are easy and the apparatus can be downsized.

The heat-sensitive transfer system is a melt transfer system in which a coloring material layer on a base material is melted by heating and is transferred to a recording material, and a so-called dye in the coloring material layer is transferred to the recording material. A sublimation transfer method is known. Since the sublimation transfer method can control the amount of dye to be transferred by the degree of heating, it is possible to perform expression with density gradation, and is suitable for obtaining a fine image including full-color printing.

A normal color print is expressed with three colors of yellow, magenta, and cyan, and a transfer sheet used in a sublimation transfer system has three color material layers of yellow, magenta, and cyan on a substrate. Many are held in sequence.
On the other hand, in order to reproduce black better, in order to reproduce and reproduce a transfer sheet having a color material layer of four colors including a color material layer dedicated to black, or a monochrome image such as X-ray. There is also a demand for a black-only transfer sheet having only the black color material layer.

The dyes in the color material layer for black are usually mixed with dyes of respective hues of yellow, magenta and cyan. For example, JP-A-61-148096 and JP-A-3-7387 are disclosed. Can be mentioned.

[0006]

In order to be a good black transfer sheet, it is possible to express dark black, that it is close to achromatic color, that the color quality does not change with the density, weather resistance such as light resistance, and storage stability. Although there are required performances such as excellent, it is extremely difficult to satisfy all of them. In order to be able to express dark black, it is necessary to use a combination of dyes with high transfer density. In combination with low transfer sensitivity, high density black cannot be expected from the beginning, but when one of the compounded dyes has low transfer sensitivity and cannot produce high dark color, the color quality of other compound dyes at high density Cannot be obtained because of the strong appearance of black.

Further, in order to be able to express black, the color tone when the color material layer resulting from the blending is transferred to the transfer material is close to an achromatic color in which a specific color is not biased, with due consideration of the colorant blending. Need to be. To be achromatic, C
A * when a * value and b * value are measured by IELAB color system
It is necessary to have a small ΔEc value (square root of a * × a * + b * × b *) from = 0 and b * = 0, which requires a fairly strict selection combination and cannot be easily achieved.

It is difficult to satisfy these conditions, but it is necessary to further satisfy the light resistance of the image. Regarding the light resistance, it is necessary to select a dye having good light resistance alone. Furthermore, for example, JP-A-63-713
As described in Japanese Patent Laid-Open No. 92-92, even dyes having good light resistance by themselves may be mixed, or if one is transferred and then the other is transferred, a mixed state occurs in a recording material. A phenomenon known as "catalytic fade" in which the light resistance is inferior to that in the case of being alone is known, and it is necessary to select a combination in which the phenomenon does not occur. Catalytic fade is difficult because it is necessary to select good ones from actual combinations because the correlation with the clear dye structure is not clear.

The disazo dye represented by the general formula (1) is already disclosed in JP-A-60-180889, and it should be blended with a blue dye having a uniform sublimation rate in the text. There is a description that it is suitable for obtaining a black color. Further, Japanese Patent Laid-Open No. 5-201147 also describes a part of the dye represented by the general formula (1). However, there is no black color that satisfies all of the above-mentioned various problems, and the present invention is based on the above-mentioned two publicly known documents. It is intended to provide a transfer sheet.

[0010]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have heated a transfer sheet provided with a coloring material layer to transfer a dye to a recording medium to obtain a recording. In a transfer sheet used in a thermal transfer recording system, a transfer sheet having a coloring material layer containing a disazo dye, a dicyanoimidazole azo dye and an indoaniline dye represented by the general formula (1) is used. It has been found that high black density can be achieved by performing recording, recording that is close to achromatic color can be obtained, and that black recording that shows high light resistance with little change in color quality due to density is possible. The invention was reached.

That is, an object of the present invention is to achieve a high black density, obtain a recording close to an achromatic color, a change in color quality due to the density is small, and a transfer that enables black recording having high light resistance. It consists in providing a seat. Therefore, the object of the present invention is to use in a thermal transfer recording method in which a transfer sheet having a coloring material layer provided on a thin leaf-shaped substrate is heated to transfer the dye in the coloring material layer to a recording medium to obtain a recording. The transfer sheet having a coloring material layer containing a disazo dye, a dicyanoimidazole azo dye and an indoaniline dye represented by the following general formula (1).

[0012]

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(Wherein X ¹ , X ² , X ³ and X ⁴ are hydrogen atom, alkyl group, alkoxy group, hydroxyl group, nitro group, cyano group, acyl group, acylamino group, alkoxycarbonyl group, alkoxycarbonylamino) A group, an alkylsulfonyl group, a sulfamoyl group optionally substituted with alkyl, or a halogen atom, and Y ¹ , Y ² , Y ³ ,
Y ⁴ , Y ⁵ and Y ⁶ represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom or a hydroxyl group, or even if Y ¹ and Y ² or Y ⁴ and Y ⁵ are linked to each other to form an aromatic ring. Good. ) Easily achieved.

The present invention will be described in detail below. The disazo dye represented by the general formula (1) is an orange dye, the dicyanoimidazole azo dye is a red dye, and the indoaniline dye is a blue dye. still,
In the substituents of the following general formulas (1) to (4), “lower” means that the carbon number is 1 to 8.

In the general formula (1), X ¹ , X ² , X
³ and X ⁴ may be substituted with a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, a nitro group, a cyano group, an acyl group, an acylamino group, an alkoxycarbonyl group, an alkoxycarbonylamino group, an alkylsulfonyl group or an alkyl. Represents a sulfamoyl group or a halogen atom, and Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom or a hydroxyl group, or Y ¹ , Y ² or Y ⁴ and Y ⁵ may combine with each other to form an aromatic ring.

Among them, X ¹ , X ² , X ³ and X ⁴ are hydrogen atom, lower alkyl group, lower alkoxy group, hydroxyl group, nitro group, cyano group, lower acylamino group, lower alkoxycarbonyl group, lower alkoxycarbonylamino. Group, methylsulfonyl group, ethylsulfonyl group, dimethylsulfamoyl group, fluorine atom, chlorine atom or bromine atom is preferable, and Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ are hydrogen atoms. , A lower alkyl group, a lower alkoxy group, a fluorine atom, a chlorine atom, a bromine atom or a hydroxyl group, or Y ¹ and Y ² or Y ⁴ and Y ⁵ are preferably linked to each other to form an aromatic ring. .

Further, X ¹ , X ² , X ³ and X ⁴ are hydrogen atom, methyl group, ethyl group, methoxy group, ethoxy group, nitro group, acetylamino group, methoxycarbonyl group, ethoxycarbonyl group, methoxycarbonylamino. Group, ethoxycarbonylamino group or chlorine atom is particularly preferable, and Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ are hydrogen atom, methyl group, ethyl group, methoxy group, ethoxy group chlorine atom. Or represents a hydroxyl group, or Y ¹ and Y ² or Y ⁴ and Y ⁵
Are particularly preferably linked to each other to form an aromatic ring.

The dicyanoimidazole azo dye in the present invention is usually a dye represented by the following general formula (2).

[0019]

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In the general formula (2), there is no particular limitation.
Not X^FiveIs a hydrogen atom, a halogen atom, a lower alkyl
Kill group, lower alkoxy group, formylamino group, lower alkyl group
Silamino group, lower alkylsulfonylamino group,
Represents a lower alkoxycarbonylamino group, Y⁷Is water
Elementary atom, halogen atom, lower alkyl group or lower alkyl
A oxy group;¹Is a lower alkyl group, lower alkene
Group, aralkyl group, hydroxy lower alkyl group, sia
Lower alkyl group, halogenoalkyl group, lower alkoxy group
Si lower alkyl group, lower alkoxycarbonyl lower alkyl
Kill group, lower alkylcarbonyloxy lower alkyl group
Or a lower acylalkyl group, R ²And R³Haso
Lower alkyl group, lower alkenyl group, aralkyl
Group, aryl group, halogeno lower alkyl group, hydroxy
Lower alkyl group, cyano lower alkyl group, tetrahydro
Furfuryl group, lower alkoxy lower alkyl group, aral
Kiroxy lower alkyl group, aryloxy lower alkyl
Group, alkenyloxy lower alkyl group, tetrahydro
Furfuryloxy lower alkyl group, lower alkoxycal
Bonyl lower alkyl group, lower alkylcarbonyloxy
Lower alkyl group, arylcarbonyloxy lower alk
Group, lower alkoxycarbonyloxy lower alkyl
Group, lower alkoxyethoxy lower alkyl group or lower
Alkoxyethoxycarbonyl lower alkyl group
And are common.

Among them, X ⁵ represents a hydrogen atom, a chlorine atom, a lower alkyl group, a lower alkoxy group, a lower acylamino group or a lower alkoxycarbonylamino group, and Y ⁷
Represents a hydrogen atom, a chlorine atom, a lower alkyl group or a lower alkoxy group, and R ¹ represents a lower alkyl group, a lower alkenyl group, an aralkyl group, a hydroxy lower alkyl group, a monochloro lower alkyl group, a cyano lower alkyl group, a lower alkoxy lower alkyl. Group, an alkoxycarbonyl lower alkyl group, a lower alkylcarbonyloxy lower alkyl group, a lower alkoxyethoxycarbonyl lower alkyl group or a lower acylalkyl group, wherein R ² and R ³ are a lower alkyl group, a lower alkenyl group, an aralkyl group and an aryl group. , Halogeno lower alkyl group, hydroxy lower alkyl group, cyano lower alkyl group, lower alkoxy lower alkyl group, aralkyloxy lower alkyl group, aryloxy lower alkyl group, lower alkenyloxy lower alkyl group, tetrahydo B furfuryl-lower alkyl group, lower alkylcarbonyloxy-lower alkyl group, arylcarbonyloxy-lower alkyl group, a lower alkoxycarbonyl-lower alkyl group, preferably represents a lower alkoxycarbonyloxy-lower alkyl group or a lower alkoxy-ethoxy-lower alkyl group.

Further, X^FiveIs a lower acylamino group or
Represents a lower alkoxycarbonylamino group, Y⁷Is hydrogen
Represents an atom, R¹Is a lower alkyl group, lower alkenyl
Group, aralkyl group, chloroethyl group, cyanoethyl group
Or lower alkoxyethyl group, R ²And R³Is lower grade
Kill group, lower alkenyl group, aralkyl group, chloreth
Group, hydroxyethyl group, cyanoethyl group, lower alkyl group
Coxyethyl group, lower aralkyloxyethyl group, ant
Group, lower alkenyloxyethyl group,
Tetrahydrofurfuryloxyethyl group, lower alkoxy
Cycarbonylethyl group, arylcarbonyloxyethyl
Group, lower alkylcarbonyloxyethyl group, lower alkyl group
Lucoxycarbonyloxyethyl group or lower alkoxy
It is particularly preferred to represent the cyethoxyethyl group.

The indoaniline dye in the present invention is not particularly limited, but examples thereof include dyes represented by the general formula (3) and the general formula (4).

[0024]

[Chemical 4]

[0025]

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In the general formula (3), although not particularly limited, X ⁶ is a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a formylamino group, a lower acylamino group, a lower alkylsulfonylamino group or a lower alkoxycarbonyl. Represents an amino group, Y ⁸ represents a hydrogen atom, a halogen atom, a methyl group or a lower alkoxy group, —A— represents —CO— or —COO—, and R ⁴
Is a lower alkyl group, a lower alkenyl group, an aralkyl group,
Aryl group, halogeno lower alkyl group, hydroxy lower alkyl group, cyano lower alkyl group, tetrahydrofurfuryl group, lower alkoxy lower alkyl group, aralkyloxy lower alkyl group, aryloxy lower alkyl group, alkenyloxy lower alkyl group, lower alkoxyethoxy A lower alkyl group, a tetrahydrofurfuryloxy lower alkyl group, a heterocycle or an alkyl group substituted with a heterocycle, wherein R ⁵ and R ⁶ are each a lower alkyl group, a lower alkenyl group, an aralkyl group, an aryl group, a halogeno lower alkyl Group, hydroxy lower alkyl group, cyano lower alkyl group, tetrahydrofurfuryl group, lower alkoxy lower alkyl group, aralkyloxy lower alkyl group, aryloxy lower alkyl group, alkenyloxy lower alkyl group Group, tetrahydrofurfuryloxy lower alkyl group, lower alkoxycarbonyl lower alkyl group, lower alkylcarbonyloxy lower alkyl group, arylcarbonyloxy lower alkyl group, lower alkoxycarbonyloxy lower alkyl group, lower alkoxyethoxy lower alkyl group or lower alkoxy Represents an ethoxycarbonyl lower alkyl group, R ⁷ and R ⁸
Are each a hydrogen atom, an alkyl group which may be substituted with a fluorine atom, an alkoxy group, a halogen atom or --NH.
It is common to represent -AR.

Among them, X⁶Is hydrogen atom, chlorine atom, low
Primary alkyl group, lower alkoxy group, or lower acyl group
Represents a mino group, Y⁸Is hydrogen atom, chlorine atom, lower alkyl
Group or a lower alkoxy group, -A- is -CO-
Or represents -COO- and R ^FourIs a lower alkyl group, lower
Alkenyl, aralkyl, aryl, halogeno low
Primary alkyl group, hydroxy lower alkyl group, cyano lower group
Alkyl group, tetrahydrofurfuryl group, lower alkoxy
Si lower alkyl group, aralkyloxy lower alkyl group,
Aryloxy lower alkyl group, alkenyloxy lower
Alkyl group, lower alkoxyethoxy lower alkyl group
Or tetrahydrofurfuryloxy lower alkyl group
Then R^FiveAnd R⁶Is a lower alkyl group, lower alkenyl
Group, aralkyl group, halogeno lower alkyl group, hydroxy group
Si lower alkyl group, cyano lower alkyl group, tetrahydr
Rofurfuryl group, lower alkoxy lower alkyl group, ara
Rukyloxy lower alkyl group, aryloxy lower alkyl
Kill group, lower alkenyloxy lower alkyl group, tetra
Hydrofurfuryloxy lower alkyl group, lower alkyl
Carbonyloxy lower alkyl group, arylcarbonyl
Oxy lower alkyl group, lower alkoxycarbonyl lower
Alkyl group, lower alkoxycarbonyloxy lower alkyl
Kill group or lower alkoxyethoxy lower alkyl group
Represent, R⁷And R⁸Is a hydrogen atom, alkyl group or halo
It preferably represents a gen atom.

Further, X ⁶ represents a hydrogen atom, a methyl group or an ethyl group, Y ⁸ represents a hydrogen atom, and -A- represents -C.
Represents O— or —COO—, R ⁴ is a lower alkyl group,
Represents a lower alkenyl group, aralkyl group, aryl group, chloroethyl group, lower alkoxyethyl group, tetrahydrofurfuryl group, aralkyloxyethyl group, aryloxyethyl group, alkenyloxyethyl group or tetrahydrofurfuryloxyethyl group, R ⁵ and R ⁶ is a lower alkyl group, a lower alkenyl group, an aralkyl group, a tetrahydrofurfuryl group, a chloroethyl group, a hydroxyethyl group, a cyanoethyl group, a lower alkoxyethyl group, a lower aralkyloxyethyl group, an aryloxyethyl group, a lower alkenyloxyethyl group. , Tetrahydrofurfuryloxyethyl group, lower alkoxycarbonylethyl group, arylcarbonyloxyethyl group, lower alkylcarbonyloxyethyl group, lower alkoxycarbonyloxyethyl group It is particularly preferable that R ⁷ represents a hydrogen atom or a chlorine atom, and R ⁸ represents a hydrogen atom, a chlorine atom, a methyl group or an ethyl group.

In the general formula (4), X ⁷ is not particularly limited, but X ⁷ is a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a formylamino group, a lower acylamino group, a lower alkylsulfonylamino group or a lower alkoxycarbonyl. Represents an amino group, Y ⁹ represents a hydrogen atom, a halogen atom, a lower alkyl group, or a lower alkoxy group, R ⁹ represents a lower alkyl group, an alkenyl group,
Aralkyl group, aryl group, halogeno lower alkyl group,
Hydroxy lower alkyl group, cyano lower alkyl group, tetrahydroxyfurfuryl group, lower alkoxy lower alkyl group, aralkyloxy lower alkyl group, aryloxy lower alkyl group, lower alkenyloxy lower alkyl group, tetrahydrofurfuryloxy lower alkyl group or lower Represents an alkoxyethoxy lower alkyl group, R
¹⁰ and R ¹¹ are each a lower alkyl group, alkenyl group, aralkyl group, aryl group, halogeno lower alkyl group, hydroxy lower alkyl group, cyano lower alkyl group, tetrahydroxyfurfuryl group, lower alkoxy lower alkyl group, aralkyloxy lower alkyl group. Group, aryloxy lower alkyl group, lower alkenyloxy lower alkyl group, tetrahydrofurfuryloxy lower alkyl group, arylcarbonyloxy lower alkyl group, lower alkylcarbonyloxy lower alkyl group, lower alkoxycarbonyl lower alkyl group, aralkyloxycarbonyl lower alkyl group Group, a lower alkoxycarbonyloxy lower alkyl group, an aralkyloxycarbonyloxy lower alkyl group or a lower alkoxyethoxy lower alkyl group. Is a basis.

Among them, X ⁷ represents a hydrogen atom, a chlorine atom, a lower alkyl group, a lower alkoxy group, a lower acylamino group or a lower alkoxycarbonylamino group, and Y ⁹
Represents a hydrogen atom, a chlorine atom, a lower alkyl group or a lower alkoxy group, and R ⁹ represents a lower alkyl group, an alkenyl group, an aralkyl group, a halogeno lower alkyl group, a hydroxy lower alkyl group, a cyano lower alkyl group, a tetrahydroxyfurfuryl group. , A lower alkoxy lower alkyl group,
An aralkyloxy lower alkyl group, an aryloxy lower alkyl group, a lower alkenyloxy lower alkyl group, a tetrahydrofurfuryloxy lower alkyl group or a lower alkoxyethoxy lower alkyl group, wherein R ¹⁰ and R ¹¹ represent a lower alkyl group, a lower alkenyl group, Aralkyl group, aryl group, halogeno lower alkyl group, hydroxy lower alkyl group, cyano lower alkyl group, tetrahydrofurfuryl group, lower alkoxy lower alkyl group, aralkyloxy lower alkyl group, aryloxy lower alkyl group, alkenyloxy lower alkyl group, Tetrahydrofurfuryloxy lower alkyl group, lower alkoxycarbonyl lower alkyl group, lower alkylcarbonyloxy lower alkyl group, arylcarbonyloxy lower alkyl group, lower alcohol Shi carbonyloxy-lower alkyl group, preferably represents a lower alkoxy-ethoxy lower alkyl group or a lower alkoxycarbonyl ethoxycarbonyl lower alkyl group.

Further, X ⁷ represents a hydrogen atom, chlorine atom, methyl group, ethyl group, methoxy group or ethoxy group, Y ⁹ represents a hydrogen atom, R ⁹ represents a lower alkyl group, a lower alkenyl group, an aralkyl group, A halogeno lower alkyl group, a lower alkoxyethyl group, a tetrahydrofurfuryl group, an aralkyloxyethyl group, an aryloxyethyl group, an alkenyloxyethyl group or a tetrahydrofurfuryloxyethyl group, wherein R ¹⁰ and R ¹¹ are a lower alkyl group, a lower Alkenyl group, aralkyl group, tetrahydrofurfuryl group, chloroethyl group, hydroxyethyl group, cyanoethyl group, lower alkoxyethyl group, lower aralkyloxyethyl group, aryloxyethyl group, lower alkenyloxyethyl group, tetrahydrofurfuryloxyethyl group, Low Alkoxycarbonyl ethyl group,
It is particularly preferable to represent an arylcarbonyloxyethyl group, a lower alkylcarbonyloxyethyl group, a lower alkoxycarbonyloxyethyl group or a lower alkoxyethoxyethyl group.

The black transfer sheet of the present invention is selected from various conceivable combinations of dyes. The disazo dye, the dicyanoimidazole azo dye and the dye represented by the general formula (1) are used. Contains an aniline dye,
It can be obtained by providing a coloring material layer using the same on a thin leaf substrate. It is necessary to mix the dyes in consideration of the transfer sensitivities of the respective dyes so that the hue of black recording obtained is stable.

Therefore, the mixing ratio of the respective dyes is such that the disazo dye represented by the general formula (1) is usually 20 to 45% by weight and the dicyanoimidazoleazo dye is 100% by weight of all the dyes in the coloring material layer. Of 10 to 30% by weight and indoaniline dye at 40 to 65% by weight, preferably 24 to 40% by weight of disazo dye and 12 to 25% of dicyanoimidazole azo dye. % By weight, 45 to 57% by weight of indoaniline dye.

The black obtained by using the transfer sheet prepared by using the dyes blended in such a blending ratio is close to an achromatic color which is not biased to a specific color, and is a color in the CIELAB color system.
The difference in color quality (ΔEc value) from (a ^* = 0, b ^* = 0) (square root of (a ^** a ^* + b ^** b ^* )) when measuring ^* value and b ^* value is 10 or less. , Preferably 6 or less. Further, its light resistance is extremely good, there is almost no discoloration or discoloration in an ordinary room, and even in an accelerated test using a xenon fedometer, the CIELAB color difference (ΔE ^*) changed in 40 hours of the test ^. ab) is 12 or less, preferably 6 or less.

Examples of the thin leaf-like substrate used here include polyethylene terephthalate film, polyamide film, polyaramid film, polyimide film, polycarbonate film, polyphenylene sulfide film, polysulfone film, cellophane, triacetate film, polypropylene film and the like. Among them, the polyethylene terephthalate film is preferable from the viewpoint of mechanical strength, dimensional stability, heat resistance, price, etc., and a biaxially stretched polyethylene terephthalate film is particularly preferable. The thickness of these thin leaf-like substrates is usually 1 to 30 μm, preferably 2 to 10 μm.

In order to improve the adhesiveness to the coloring material layer, the thin leaf-shaped substrate is subjected to corona treatment on the surface of the base film, or a polyester resin, a cellulose resin, a polyvinyl alcohol resin, a urethane resin. An anchor coat made of resin, polyvinylidene chloride resin, or the like may be provided. The coloring material layer may be formed on the thin leaf-shaped substrate by a usual method. For example, a dye and a binder resin having good heat resistance may be dissolved or dispersed in an appropriate solvent to prepare an ink, and the ink may be applied to a base film and dried.

Generally, the higher the ratio of the dye in the binder resin, the higher the transfer sensitivity and the maximum attainable density, and the lower the ratio of the dye, the lower the sensitivity and the ultimate density. However, if the ratio of the dye becomes extremely high, the dye will precipitate from the binder under high temperature, high humidity, or long-term storage, which will have a bad effect on the transferred image. Therefore, in view of the trade-off between storage stability and transferability of the transfer sheet, the mixing ratio of the binder and the dye is preferably in the range of 1: 2 to 2: 1, more preferably 1: 1.5 to 1. It is in the range of 5: 1.

As the binder resin in this case, polycarbonate resin, polysulfone resin, polyvinyl butyral resin, phenoxy resin, polyarylate resin, polyamide resin, polyaramid resin, polyimide resin, polyetherimide resin, polyester resin, acrylonitrile-styrene resin and Examples include cellulosic resins such as acetyl cellulose, methyl cellulose, ethyl cellulose and the like. As the solvent used, aromatic solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ester solvents such as ethyl acetate and butyl acetate; alcohols such as isopropanol, butanol and methyl cellosolve. Examples thereof include ether solvents such as dioxane and tetrahydrofuran; amide solvents such as dimethylformamide and N-methylpyrrolidone.

In the above ink, in addition to the above components, organic or inorganic non-sublimable particles, a dispersant, an antistatic agent, an antiblocking agent, an antifoaming agent, an antioxidant,
Additives such as viscosity modifiers can be added. Further, an infrared absorber or carbon black may be added for use in a sublimation transfer method using laser light.

The method of applying these inks is not particularly limited, but, for example, a gravure coater, a reverse roll coater, or the like can be used. For example, "Printing ink handbook" (edited and published by Printing Ink Industry Federation, 197).
8 years) can be referred to. The dry coating film thickness is preferably 0.1 to 5 μm, more preferably 0.5 to 2 μm.

If desired, a heat-resistant layer may be provided on the surface of the transfer sheet opposite to the color material layer. The heat resistant layer is not particularly limited, but for example, one using a cured resin such as an ultraviolet curable resin or one using a thermoplastic resin having a high Tg is known. Since the heat resistant layer is required to have heat resistance against the heat of the thermal head as well as slipperiness with respect to the thermal head, a lubricant such as silicone oil is generally added.

[0042]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded. Unless otherwise stated,% and the number of parts are calculated by weight. [Example 1] (a) Preparation of transfer sheet Dye 1-1 (in the general formula (1), X ¹ , X ² , X ³ ,
X ⁴ , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ each represent a hydrogen atom, and Y ¹ and Y ² are bonded to each other to form a 6-membered aromatic ring having no substituent other than a hydrogen atom on the aromatic ring. Represents a ring. ) 32
, Dye 2-1 (in the general formula (2), X ⁵ represents an acetylamino group, Y ⁷ represents a hydrogen atom, R ¹ represents an allyl group, R ² Y and R ³ represent normal propyl groups, respectively. ) 20 copies,
Dye 3-1 (in the general formula (3), X ⁶ is a methyl group, Y ⁸
Is a hydrogen atom, A is —CO—, R ⁴ is a methyl group, R ⁵ and R
⁶ represents an ethyl group, R ⁷ represents a hydrogen atom, and R ⁸ represents a methyl group. ) 48 parts and AS resin (trade name "Sunlex S"
AN-A ", manufactured by Monsanto Kasei Co., Ltd.), 125 parts of methyl ethyl ketone, 200 parts of toluene, and 500 parts of toluene were mixed and stirred to obtain an ink having a dry film thickness of 2 μm on a 6 μm polyester film using a bar coater. After coating and drying, acrylic resin (brand name "BR" on the back
-80 ", manufactured by Mitsubishi Rayon Co., Ltd., 10 parts by weight, amino-modified silicone oil (trade name" KF393 ", manufactured by Shin-Etsu Chemical Co., Ltd.) 1 part by weight, and 89 parts by weight of toluene were mixed and dissolved, using a bar coater. The coating was dried to a dry thickness of 1 μm to form a heat resistant layer.

(B) Preparation of Image Receptor 70 parts of polyvinyl phenyl acetal resin, vinyl chloride / vinyl acetate / vinyl alcohol copolymer resin (trade name)
S-REC A ", manufactured by Sekisui Chemical Co., Ltd., 30 parts, Silicone varnish (trade name TSR-160, solid content concentration 60)
%, Manufactured by Toshiba Silicone Co., Ltd., 30 parts, hexamethylene diisocyanate-based polyfunctional isocyanate compound (trade name “Mytec NY-710A”, solid content concentration 75)
%, Manufactured by Mitsubishi Kasei Co., Ltd.), amino-modified silicone oil (trade name "KF393", manufactured by Shin-Etsu Chemical Co., Ltd.) 2.5 parts, methyl ethyl ketone 600 parts, toluene 600 parts, a synthetic paper (trade name) "Yupo FPG1
50 ", manufactured by Oji Yuka Synthetic Paper Co., Ltd., was coated with a wire bar, dried (dry film thickness: about 5 µm), and further heat-treated in an oven at 80 ° C for 12 hours to prepare an image receptor.

The above polyvinyl phenyl acetal resin is polyvinyl alcohol (saponification degree: 99 mol%, polymerization degree: 1).
It was obtained by acetalizing 700) with phenylacetaldehyde and has the following structural formula (5).

[0045]

[Chemical 6]

(C) Print recording The color material layer surface of the thermal transfer recording sheet prepared as described in (a) above and the resin coated surface of the image receptor prepared as described above in (b) are superposed. 16m at 6 lines (dots) / mm in the feed direction by using a partial Grace type line thermal head having a heating resistor density of 6 dots / mm
Printing was performed at an applied power of 0.20 W / dot at a speed of s / line. By setting the time applied to the head per line to 13 ms and 8 ms, respectively, dark color,
And a light-colored print was obtained. (D) Measurement of Density and Chromaticity A dark-colored reflection densitometer (trade name "Macbeth RD-927 type", manufactured by Macbeth Co.) of the printed matter printed as described in (c) above, and the filter was ortho-matched. It was measured. As a result, a concentration of 1.50 could be obtained.

Further, the CIELA for each of the light color and the dark color
B chromaticity is measured with a C light source and a viewing angle of 2 degrees using a color difference meter (trade name "spectral color difference meter SZ-Σ80", manufactured by Nippon Denshoku Industries Co., Ltd.) having an optical system conforming to JIS Z-8722. did. As a result, for dark colors, a ^* =-1.5, b ^* =-
2.2, in light color, a ^* =-1.7 and b ^* =-0.2, and the difference in color quality (ΔEc) from a ^* = 0 and b ^* = 0 is 2.7. It was 1.7, which was close to an achromatic color. (E) Light resistance test A dark color sample of the printed matter printed as described in (c) above is used as a light resistance tester (trade name) using a xenon lamp.
A xenon fade meter FAL-25AX ", manufactured by Suga Test Instruments Co., Ltd.) was used to perform a 40-hour light resistance test. The printed matter before the test and that after the test were the same color difference meter as used in (d). It was measured under the same conditions.
The AB color difference (ΔE ^* ab) was as small as 2.7.

[Examples 2 to 7] The same as Example 1 except that the combinations and amounts of the dyes shown in Table 1 below were used instead of the combinations and amounts of the dyes used in Example 1. Tests were conducted and the results are shown in Table-3. In each case, a black color close to a medium color was obtained at a high concentration, and the light resistance was good.

[0049]

[Table 1]

In Table 1 above, the dye 1-2 is a dye
In the formula (1), X¹, X², X³, X^Four, Y², Y^Four, Y^Five
And Y⁶Are hydrogen atoms, Y¹And Y³Are each
Represents a toxic group. The dye 2-2 is represented by the general formula (2):
X^FiveIs an acetylamino group, Y⁷Is a hydrogen atom, R¹, R²as well as
R³Each represents a normal butyl group. Dye 3-2
Is X in the general formula (3).⁶Is a methyl group, Y⁸Is hydrogen
Child, A is -COO-, R^FourIs an ethyl group, R^FiveAnd R⁶Haso
Ethyl group, R⁷Is a chlorine atom, R ⁸Represents a methyl group
You.

The dye 3-3 is a compound represented by the formula (3): X ⁶
And Y ⁸ are each a hydrogen atom, A is —CO—, R ⁴ is a methyl group, R ⁵ and R ⁶ are ethyl groups, and R ⁷ and R ⁸ are each a hydrogen atom. The dye 3-4 is the same as X in the general formula (3).
⁶ is a methyl group, Y ⁸ is a hydrogen atom, A is —CO—, R ⁴ is a methyl group, R ⁵ and R ⁶ are ethyl groups, R ⁷ is a chlorine atom, and R ⁸ is a methyl group. In the general formula (4), the dye 4-1 has hydrogen atoms represented by X ⁷ and Y ⁹ , a butyl group represented by R ⁹ , and ethyl groups represented by R ¹⁰ and R ¹¹ .

Comparative Examples 1 to 3 Similar to Example 1 except that the combination and amount of dyes used in Example 1 were replaced by the combination and amount of dyes shown in Table 2 below. Test,
The results are shown in Table-3. In Comparative Examples 1 and 2, although light having a moderate and high sensitivity was obtained, the light resistance was insufficient. In Comparative Example 3, the light resistance was good, but the sensitivity was low, and the difference in color quality when the density was different was large. The dye 5 is a yellow dye, and the dye 6
Is a red pigment, and the pigment 7 is a blue pigment.

[0053]

[Table 2]

In Table 2, the dye 5 has the following structural formula (6):
The dye 6 is shown in the following structural formula (7), and the dye 7 is shown in the following structural formula (8).

[0055]

[Chemical 7]

[0056]

Embedded image

[0057]

[Chemical 9]

[0058]

[Table 3]

[0059]

When the transfer sheet of the present invention is used, dark black can be expressed, the color thereof is close to an achromatic color, and the light resistance is excellent.

[Procedure amendment]

[Submission date] January 11, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0052

[Correction method] Change

[Correction content]

[Comparative Examples 1 and 2 ] The same as Example 1 except that the combination and amount of dyes shown in Table 2 below were used instead of the combination and amount of dyes used in Example 1. Test,
The results are shown in Table-3. Oite in Comparative Example 1, although sensitive black was obtained in moderate light resistance was insufficient. In Comparative Example 2 , the light resistance was good, but the sensitivity was low, and the difference in color quality when the density was different was large. The pigment 5 is a yellow pigment, the pigment 6 is a red pigment, and the pigment 7 is a blue pigment.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0053

[Correction method] Change

[Correction content]

[0053]

[Table 2]

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0058

[Correction method] Change

[Correction content]

[0058]

[Table 3]

Claims (2)

[Claims] 1. A transfer sheet used in a heat-sensitive transfer recording method, wherein a transfer sheet having a coloring material layer provided on a thin-leaf substrate is heated to transfer the dye in the coloring material layer to a recording medium for recording. A transfer sheet having a coloring material layer containing a disazo dye represented by the following general formula (1), a dicyanoimidazole azo dye, and an indoaniline dye. Embedded image (In the formula, X ¹ , X ² , X ³ and X ⁴ are a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, a nitro group, a cyano group, an acyl group, an acylamino group, an alkoxycarbonyl group, an alkoxycarbonylamino group, an alkyl group. A sulfonyl group, a sulfamoyl group optionally substituted with alkyl, or a halogen atom, and Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ are a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom or Represents a hydroxyl group, or Y ¹ and Y ² or Y ⁴ and Y ⁵
May be linked to each other to form an aromatic ring. ) 2. 100% by weight of a pigment contained in the coloring material layer
The disazo dye represented by the general formula (1) is 20 to
45% by weight, 10% of dicyanoimidazole azo dye
30% by weight, 40-65% by weight of indoaniline dye
The transfer sheet according to claim 1, wherein the transfer sheet is contained in the following ratio.