JP2000185475A - Thermal transfer sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high density cyan image of a green expression by incorporating at least two types of dyes represented by specific formulae in a cyan color material layer. SOLUTION: A cyan color material layer contains at least two types of dyes represented by formulae, λmax of the dyes are 635 to 686 nm, and a total sum of number of carbons of a substituent represented by R1 of the dyes in the formulae is 3 or more, wherein -A- is -NHCO-, -NHCOO-, -CONH- or -CONR6-, wherein R1, R6 are each a group which may be substituted (an alkyl group, lower alkenyl group, aryl group or aralkyl group) or alkyl group or a heterocycle which may be substituted by an alkyl group or a halogen atom, R2 and R3 are each independently is an alkyl group which may be substituted, R4, R5 are each a hydrogen atom or a lower alkyl group which may be substituted, X1 is a hydrogen atom or a halogen atom, X1 is bonded to R4 and it may form a ring which may be substituted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In recent years, techniques for converting a color image based on an electric signal such as a video image into a color hard copy have been advanced, and for example, methods such as electrophotography, ink jet, and thermal transfer have been studied. Among them, the thermal transfer method is particularly advantageous from the viewpoints of easy maintenance and operation of the apparatus, miniaturization of the apparatus, and the like. In the thermal transfer method, the coloring material layer on the substrate is melted by heating,
There are known a fusion transfer method in which the dye is transferred to an image receiving sheet, and a so-called sublimation transfer method in which only a dye in a color material layer is transferred to a recording material. The sublimation transfer method can control the amount of the dye to be transferred by the degree of heating, and therefore can express density gradation, and is suitable for obtaining a fine image such as a full-color print. A normal color print is expressed by three primary colors of yellow, magenta, and cyan, and a thermal transfer sheet used for the sublimation transfer method is also usually three colors of yellow, magenta, and cyan, or
Color material layers of four colors including black are sequentially arranged on the base material. In order to faithfully reproduce colors from video image signals, it is desirable that the three primary colors of yellow, magenta, and cyan of the thermal transfer sheet be close to the colors of the primary colors of the video signal. In particular, cyan is less than cyan used in offset printing, for example. There is a need for something very green. Further, the completed image must be able to withstand storage in a poor environment, and for this purpose, for example, resistance to light and physical stimuli is also required.

[0003]

Various studies have been made on the cyan color material layer. For example, JP
In Japanese Patent Application Laid-Open No. 3-199687, it is disclosed that a plurality of cyan dyes are blended. In any case, a combination of the dyes mentioned in the specific examples gives a green cyan image with high density. Further, a cyan color material layer in which the obtained image has sufficient resistance to light and physical stimulus (image stability) has not been obtained. In particular, the green cyan dye tends to precipitate crystals from the printed image due to high temperature storage or physical stimuli such as scratches, and there is a problem in the storage stability of the green cyan image. Accordingly, an object of the present invention is to provide a green cyan image at high density by thermal transfer, and to provide an image having good image storage stability, that is, a crystal which is not easily precipitated by various physical stimuli and has good light fastness. An object of the present invention is to provide a thermal transfer sheet.

[0004]

In a print image obtained by thermal transfer, the transferred dye exists in a largely concentrated state near the surface, and as the distance from the surface increases (deepens), the dye is increased. It is generally considered that the state has a large concentration gradient in the depth direction, in which the concentration rapidly decreases. In such a state, it is difficult to predict a phenomenon as compared with a normal homogeneous system, and it is unlikely that the same phenomenon as in a homogeneous system occurs. Therefore, regarding the problem of dye crystal precipitation from an image, regardless of the presence or absence of scratches on the image, it is not clear how to make the precipitation of the dye crystal unlikely. There is no.

As a result of extensive studies, the present inventors have found that using a thermal transfer sheet in which two or more kinds of cyan dyes having a specific structure are combined in a cyan color material layer to provide a high density greenish cyan It has been found that an image can be obtained and good image storage stability can be obtained even under various storage conditions, and the present invention has been achieved. That is, the gist of the present invention is a heat-sensitive transfer sheet having a cyan color material layer provided on at least one surface of a substrate, wherein the cyan color material layer contains at least two kinds of dyes represented by the following general formula (1). Λmax of these dyes is 635 to 685 nm.
Wherein the total number of carbon atoms of the substituent represented by R ¹ of each of these dyes is 3 or more.

[0006]

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(Wherein -A- is -NHCO-, -NHC
OO -, - CONH-, or -CONR ⁶ - represents,
R ⁶ represents an alkyl group which may be substituted, a lower alkenyl group which may be substituted, an aryl group which may be substituted, an aralkyl group which may be substituted, or an alkyl group or a halogen atom. Represents a heterocyclic ring which may be R ¹ is an optionally substituted alkyl group, an optionally substituted lower alkenyl group, an optionally substituted aryl group, an optionally substituted aralkyl group, or an alkyl group or a halogen atom. R ² and R ³ each independently represent an optionally substituted alkyl group;
R ⁴ represents a hydrogen atom or a lower alkyl group which may be substituted, R ⁵ represents a hydrogen atom or a lower alkyl group which may be substituted, and X ¹ represents a hydrogen atom or a halogen atom. X ¹ may be linked to R ⁴ to form an optionally substituted ring. ).

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The heat-sensitive transfer sheet of the present invention is composed of a substrate and a cyan color material layer provided on at least one surface thereof, and preferably has a cyan color material layer and a yellow color material layer, more preferably yellow, magenta , Cyan, or four color material layers obtained by adding a black color material layer to these three primary colors. In the present invention, the cyan color material layer has a maximum absorption wavelength at 400 to 700 nm of 58.
It refers to a color material layer located at 0 to 700 nm.

As the substrate, a thin leaf film is usually used, and specifically, a polyethylene terephthalate film, a polyamide film, a polyaramid film, a polyimide film, a polycarbonate film, a polyphenylene sulfide film, a polysulfone film,
Cellophane, triacetate film, polypropylene film and the like can be mentioned, preferably a polyethylene terephthalate film, particularly preferably a biaxially stretched polyethylene terephthalate film. Polyethylene terephthalate film is suitable in terms of mechanical strength, dimensional stability, heat resistance, price, and the like. The thickness of the substrate is usually 1 to 30 μm, preferably 2 to 10 μm.

[0010] Even if the surface of the substrate is subjected to a corona treatment in order to improve the adhesion to the colorant layer, the base material may be a polyester resin, a cellulose resin, a polyvinyl alcohol resin, a urethane resin, a polychlorinated resin. An anchor coat made of a resin such as a vinylidene resin may be provided. The color material layer
Usually contains a dye and a binder resin. The thermal transfer sheet of the present invention has a cyan color material layer containing at least two kinds of cyan dyes having λmax of 635 to 685 nm. These cyan dyes preferably have the general formula (1)
And at least two types of the dyes represented by the general formula (1) are more preferably contained.

[0011]

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In the general formula (1), -A- is -NHC
O-, -NHCOO-, -CONH-, or -CON
R ^6- , preferably -NHCO-, -NHCOO
-, Or -CONH-, more preferably -NH
Represents CO- or -NHCOO-. R ⁶ represents an alkyl group which may be substituted, a lower alkenyl group which may be substituted, an aryl group which may be substituted, an aralkyl group which may be substituted, or an alkyl group or a halogen atom. Represents a heterocyclic ring which may be R
¹ is an alkyl group which may be substituted, a lower alkenyl group which may be substituted, an aryl group which may be substituted, an aralkyl group which may be substituted, or which is substituted with an alkyl group or a halogen atom. Preferably represents an alkyl group, a lower alkenyl group, an aryl group, an aralkyl group, a lower alkyl group substituted with a halogen atom, a lower alkyl group substituted with a hydroxyl group, a lower alkyl substituted with a cyano group. Group, an alkyl group having an ether bond, an alkyl group substituted with a heterocyclic ring, or a heterocyclic ring, more preferably a lower alkyl group, a lower alkenyl group, an aryl group having 6 to 10 carbon atoms, Aralkyl group, chloroethyl group, lower alkoxyalkyl group, tetrahydrofurfuryl group, having 9 to 12 carbon atoms Represents an aralkyloxyethyl group, an aryloxyethyl group having 8 to 12 carbon atoms, a lower alkenyloxyethyl group, or a heterocyclic ring containing O, N or S as a hetero atom, more preferably a lower alkyl group or a lower alkenyl group , Phenyl group, toluyl group, benzyl group, tetrahydrofurfuryl group, lower alkoxy lower alkyl group, furyl group, pyridyl group, or thienyl group, particularly preferably methyl group, ethyl group, propyl group, butyl group, pentyl group , Benzyl group,
Represents a lower alkoxyethyl group or a furyl group.

R ² is an alkyl group which may be substituted,
Preferably lower alkyl group, more preferably methyl group,
It represents an ethyl group, a propyl group, or a butyl group, more preferably represents an ethyl group, a propyl group, or a butyl group, and particularly preferably represents an ethyl group. R ³ represents an optionally substituted alkyl group, preferably a lower alkyl group, a lower alkyl group substituted with a halogen atom, a lower alkyl group substituted with a hydroxyl group, a lower alkyl group substituted with an amino group, Represents an alkyl group having an ether bond, an alkyl group having an amide bond, or an alkyl group having a sulfonylamino bond, more preferably a lower alkyl group, a chloroethyl group, a hydroxyethyl group, a lower alkoxyethyl group, and a C9 to C12 alkyl group. It represents an aralkyloxyethyl group or an aryloxyethyl group having 8 to 12 carbon atoms, more preferably an ethyl group, a propyl group or a butyl group, particularly preferably an ethyl group.

R ⁴ represents a hydrogen atom or a lower alkyl group which may be substituted, preferably a hydrogen atom, a methyl group or an ethyl group, more preferably a methyl group or an ethyl group. R ⁵ represents a hydrogen atom or an optionally substituted lower alkyl group, preferably a hydrogen atom or a methyl group, more preferably a methyl group. X ¹ represents a hydrogen atom or a halogen atom, and X ¹ may be linked to R ⁴ to form an optionally substituted ring. Preferably, X ¹ represents a hydrogen atom, a chlorine atom or a bromine atom, more preferably a chlorine atom. If X ¹ is a chlorine atom, the color of the dye represented by the general formula (1) becomes greenish, and
ax tends to be in the range of 635 to 685 nm. As a preferred example of the general formula (1), -A- is -N
R ¹ represents a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a benzyl group, a lower alkoxyethyl group, or a furyl group; R ² and R ³ represent an ethyl group; R ⁴ represents a methyl group or an ethyl group, R ⁵ represents a hydrogen atom or a methyl group, and X ¹ represents a chlorine atom.

In the present invention, the compound represented by the general formula (1)
Less dye having λmax between 635 and 685 nm
When two types are mixed, R
¹The total number of carbon atoms of the substituent represented by must be 3 or more
There is. If the total number of carbon atoms is less than 3, print
Crystals easily precipitate from the image, and the effects of the present invention cannot be obtained.
No. The cyan color material layer used in the present invention generally has a general formula
Contains at least two kinds of dyes represented by (1),
The combination of the dyes is preferably represented by the general formula (1).
Then X¹At least one dye having a halogen atom
Or R in the general formula (1)^FiveIs replaced
At least one lower alkyl group dye
, The combination containing X in the general formula (1)¹But c
At least one dye which is a logen atom and a general formula
X in (1)¹Is a halogen atom
And the combination containing one type or the general formula (1)
Then X ¹At least one dye having a halogen atom
And R in the general formula (1) ^FiveIs a methyl group or d
Combination containing at least one kind of dye that is a tyl group
It is.

In the cyan transfer material layer of the thermal transfer sheet of the present invention, the content of the cyan dye having a λmax of 635 to 685 nm is usually 10% by weight or more based on the total weight of the cyan dye in the cyan transfer material layer. It is preferably at least 20% by weight, more preferably at least 25% by weight. The dye represented by the general formula (1) may be a little too greenish to express the cyan color of the target video signal. Therefore, the cyan color material layer of the thermal transfer sheet of the present invention has a λmax of 63.
In addition to at least two cyan dyes of 5 to 685 nm, 555 to 635 when measured in a toluene solution.
It preferably contains at least one cyan dye having an absorption peak at nm. As the cyan dye having an absorption peak at 555 to 635 nm, a group consisting of the general formula (2), the general formula (3), and the general formula (4) in terms of light fastness, storage stability of an image, and printing density. At least one type of dye selected from the group consisting of
And at least one dye selected from the group consisting of the general formula (3), and more preferably at least one dye represented by the general formula (2).

[0017]

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In the general formula (2), -D- is -NHC
O-, -NHCOO-, -CONH-, or -CON
R ¹⁶ —, preferably represents —NHCO—, —NHCOO—, or —CONH—, more preferably —NHCO— or —NHCOO—. R ¹⁶ is an optionally substituted alkyl group, an optionally substituted lower alkenyl group, an optionally substituted aryl group, an optionally substituted aralkyl group, or an alkyl group or a halogen atom. Represents a heterocyclic ring which may be R ¹¹ is an optionally substituted alkyl group, an optionally substituted lower alkenyl group, an optionally substituted aryl group, an optionally substituted aralkyl group, or an alkyl group or a halogen atom. Represents a heterocyclic ring which may be
Preferably an alkyl group, a lower alkenyl group, an aralkyl group, an aryl group, a lower alkyl group substituted with a halogen atom, a lower alkyl group substituted with a hydroxyl group, a lower alkyl group substituted with a cyano group, an alkyl group having an ether bond A lower alkyl group, a lower alkenyl group, an aralkyl group having 7 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, a chloroethyl group, or a lower group. Alkoxyalkyl group, tetrahydrofurfuryl group, carbon number 9 to
12 represents an aralkyloxyethyl group, an aryloxyethyl group having 8 to 12 carbon atoms, a lower alkenyloxyethyl group, or a heterocyclic ring containing O, N or S as a hetero atom, and more preferably a lower alkyl group;
Lower alkenyl group, phenyl group, toluyl group, benzyl group, tetrahydrofurfuryl group, lower alkoxy lower alkyl group, furyl group, pyridyl group, or thienyl group, particularly preferably methyl group, ethyl group, propyl group, butyl group , A pentyl group, a benzyl group, a lower alkoxyethyl group, or a furyl group.

R ¹² is an alkyl group which may be substituted,
Preferably lower alkyl group, more preferably methyl group,
It represents an ethyl group, a propyl group or a butyl group, more preferably an ethyl group, a propyl group or a butyl group, particularly preferably an ethyl group. R ¹³ represents an optionally substituted alkyl group, preferably a lower alkyl group, a lower alkyl group substituted with a halogen atom, a lower alkyl group substituted with a hydroxyl group, a lower alkyl group substituted with an amino group, Represents an alkyl group having an ether bond, an alkyl group having an amide bond, or an alkyl group having a sulfonylamino bond, more preferably a lower alkyl group, a chloroethyl group, a hydroxyethyl group, a lower alkoxyethyl group, and a C9 to C12 alkyl group. It represents an aralkyloxyethyl group or an aryloxyethyl group having 8 to 12 carbon atoms, more preferably an ethyl group, a propyl group or a butyl group, particularly preferably an ethyl group.

R ¹⁴ represents a hydrogen atom or a lower alkyl group which may be substituted, preferably a hydrogen atom, a methyl group or an ethyl group, more preferably a methyl group or an ethyl group. R ¹⁵ represents a hydrogen atom or a lower alkyl group which may be substituted, preferably a hydrogen atom or a methyl group. X ² represents a hydrogen atom or a halogen atom,
X ² may combine with R ¹⁴ to form an optionally substituted ring. Preferably, X ² is a hydrogen atom, a chlorine atom,
Or, it represents a bromine atom, and X ² may be connected to R ¹⁴ to form an optionally substituted ring. More preferably,
X ² represents a hydrogen atom. If X ² is a hydrogen atom, the color of the dye represented by the general formula (2) tends to be reddish, so that the dye has an absorption wavelength in the range of 555 to 635 nm. Preferred examples of the general formula (2) include -D-
It represents -NHCO- or -NHCOO-, R ¹¹ is a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a benzyl group, a lower alkoxy ethyl group or represents furyl group, R ¹² and R ¹³ are ethyl, R ¹⁴ represents a methyl group or an ethyl group; R ¹⁵ represents a hydrogen atom or a methyl group; and X ² represents a hydrogen atom.

[0021]

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In the general formula (3), R ²¹ and R ²² each independently represent a lower alkyl group which may be substituted, a lower alkenyl group which may be substituted, an aryl group which may be substituted, or Represents an aralkyl group which may be substituted, and R ²¹ and R ²² may combine to form a ring; Preferably, R ²¹ and R ²² are each independently substituted with a lower alkyl group, a lower alkenyl group, an aralkyl group, an aryl group, a lower alkyl group substituted with a halogen atom, a lower alkyl group substituted with a hydroxyl group, and a cyano group. Lower alkyl group, lower alkoxy lower alkyl group, lower alkenyloxy lower alkyl group, lower aralkyloxy lower alkyl group, aryloxy lower alkyl group, tetrahydrofurfuryloxy lower alkyl group, lower alkoxycarbonyl lower alkyl group, arylcarbonyloxy Represents a lower alkyl group, a lower alkylcarbonyloxy lower alkyl group, a lower alkoxycarbonyloxy lower alkyl group, or a lower alkoxyethoxy lower alkyl group. More preferably, R ²¹ and R ²² are a lower alkyl group, a lower alkenyl group,
Aralkyl group, monochloro lower alkyl group, hydroxy lower alkyl group, cyanoethyl group, lower alkoxyethyl group, lower alkenyloxyethyl group, lower aralkyloxyethyl group, aryloxyethyl group, tetrahydrofurfuryloxyethyl group, or lower alkoxyethoxyethyl Represents a group.

R ²³ is a hydrogen atom, a halogen atom, an optionally substituted lower alkyl group, an optionally substituted lower alkenyl group, an optionally substituted lower alkoxy group, a formylamino group, a substituted Represents an optionally substituted acylamino group, an optionally substituted lower alkylsulfonylamino group, or a lower alkoxycarbonylamino group, preferably a hydrogen atom, a chlorine atom, a methyl group, an ethyl group, a propyl group, a butyl group, or a substituted And preferably represents an acylamino group, more preferably a hydrogen atom, a methyl group, a chlorine atom, or an acylamino group. R ²⁴ represents a hydrogen atom, a halogen atom, an optionally substituted lower alkyl group, an optionally substituted lower alkoxy group, or an optionally substituted lower alkenyl group, preferably a hydrogen atom, a halogen atom, Carbon number 4
It represents the following alkyl group or an alkoxy group having 4 or less carbon atoms, more preferably a hydrogen atom or a methoxy group.

Preferred examples of the general formula (3) include R^{twenty one}
And R^{twenty two}Represents a lower alkyl group, a lower alkenyl group,
Alkyl group, lower monoalkyl group, lower hydroxy group
Alkyl group, cyanoethyl group, lower alkoxyethyl
Group, lower alkenyloxyethyl group, lower aralkyl group
Xyethyl group, aryloxyethyl group, tetrahydro
Furfuryloxyethyl group or lower alkoxy eth
Represents a xyethyl group; ^{twenty three}Is hydrogen atom, methyl group, chlorine
An atom or an acylamino group;^{twenty four}Is a hydrogen atom,
Or a methoxy group.

[0025]

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In the general formula (4), R ³¹ and R ³² each independently represent a hydrogen atom, an optionally substituted lower alkyl group, an optionally substituted lower alkenyl group, an optionally substituted cycloalkyl Represents an optionally substituted aryl group, or an optionally substituted heterocyclic group. Preferably, R ³¹ and R ³² are each independently a hydrogen atom, an optionally substituted lower alkyl group,
Represents an optionally substituted lower alkenyl group or an optionally substituted lower aryl group. More preferably, R ³¹ and R ³² each independently represent a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a phenyl group, or a toluyl group.

The mixing ratio of the greenish cyan dye having λmax of 635 to 685 nm and the reddish cyan dye having an absorption peak at 555 to 635 nm is usually 9% by weight.
7.5: 2.5-30: 70, preferably 95: 5-5
0:50. In order to faithfully reproduce the color of the cyan primary color of the video signal, the hue angle of the printed matter when the cyan color material layer is thermally transferred to the following specific recording material is usually 210
To 245 degrees, preferably 215 to 235 degrees. Recording material for examining hue angle: 65 parts of polyvinyl phenyl acetal resin, vinyl chloride / vinyl acetate / vinyl alcohol copolymer resin (trade name:
35 parts of VAGD, manufactured by Union Carbide Co., Ltd., 15 parts of silicone varnish for modification (trade name: TSR-160, solid content concentration: 60%, manufactured by Toshiba Silicone Co., Ltd.), hexamethylene diisocyanate-based polyfunctional isocyanate compound (product) Name: Mytec NY-710A, solid content concentration 7
6%, 5% amino-modified silicone oil (trade name: KF393, Shin-Etsu Chemical Co., Ltd.)
One part, 300 parts of methyl ethyl ketone and 300 parts of toluene were mixed and stirred to prepare a coating solution. Here, “part” indicates “part by weight” and “%” indicates “% by weight”. This coating solution was applied to a thickness of 150 μm
Polypropylene synthetic paper (trade name: YUPO FPG15)
0, manufactured by Oji Yuka Synthetic Paper Co., Ltd.) with a wire bar.
After drying (dry film thickness about 5 μm), furthermore,
An image receptor was produced by heat treatment at 48 ° C. for 48 hours.
The above polyvinyl phenyl acetal resin was obtained by acetalizing polyvinyl alcohol (degree of saponification: 99 mol%, degree of polymerization: 1700) with phenylacetaldehyde, and had a structure represented by the following formula.

[0028]

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The hue angle in the present invention is measured for a color having a color density of around 1.0 measured using a DIN-NB filter under an observation condition of a D50 light source and a viewing angle of 2 degrees.
The hue angle is arcta in the CIELAB color space.
It is represented by n (b ^* / a ^* ), and is defined to be 180 degrees to 270 degrees when a ^* <0 and b ^* <0. As a method of adjusting the hue angle, for example, a method of selecting a substituent of the dye represented by the general formula (1), or a method in which λmax is 635 to 635
A method of changing the mixing ratio of a dye having a wavelength of 685 nm and a dye having an absorption peak between 555 and 635 nm can be mentioned. The yellow colorant layer used in the heat-sensitive transfer sheet of the present invention is usually a pyridone yellow dye, a quinophthalone yellow dye, a pyrazolone yellow dye, a pyrazole yellow dye, and a yellow dye selected from the group consisting of disazo yellow dyes. And preferably at least two yellow pigments selected from these groups. Lightfastness of the printed matter, in view of the sharpness of the green printed matter when combined with the cyan dye, more preferably the yellow colorant layer is a pyridone-based yellow dye, a quinophthalone-based yellow dye, and a pyrazolone-based yellow dye. 1 yellow pigment selected
Types, particularly preferably at least two types of yellow pigments selected from these groups. The pyridone-based yellow pigment used in the present invention is generally represented by the general formula (5).

[0030]

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In the general formula (5), R ⁴¹ represents a lower alkyl group, preferably represents a methyl group or an ethyl group, and more preferably represents a methyl group. R ⁴² represents an alkyl group which may be substituted or an alkenyl group which may be substituted, preferably represents an alkyl group, an aralkyl group, or an alkoxyalkyl group, and more preferably represents a lower alkyl group, a benzyl group, or a lower alkyl group. Represents an alkoxyalkyl group. R ⁴³ represents a hydrogen atom, a halogen atom, an optionally substituted lower alkyl group, a cyano group, -OX
³ group, -COX ³ group, or an -COOX ³ group, preferably represents a hydrogen atom, a halogen atom, an optionally substituted lower alkyl group, -OX ³ group, or -COOX ³ group, more preferably Represents a hydrogen atom.

R ⁴⁴ and R ⁴⁵ each independently represent a hydrogen atom, a halogen atom, a lower alkyl group which may be substituted, a cyano group, a —OX ³ group, a —COX ³ group, or a —C
It represents OOX ³ groups, each preferably independently a hydrogen atom, a halogen atom, an optionally substituted lower alkyl group, -OX ³ groups, or represents a -COOX ³ group, more preferably each independently a hydrogen atom , A fluorine atom, a chlorine atom, a lower alkyl group, a trifluoromethyl group, -OX
It represents ³ group, or -COOX ³ group, X ³ represents optionally substituted lower alkyl group, an optionally substituted aryl group or a heterocyclic ring which may be substituted.
Preferably, X ³ is an alkyl group having one or more ether bonds such as a lower alkyl group, an alkoxyalkyl group, an alkoxyalkoxyalkyl group, an optionally substituted phenyl group, an aralkyl group, or an optionally substituted Represents a heterocyclic ring. More preferably, X ³ represents a lower alkyl group, a lower alkoxyalkyl group, an optionally substituted phenyl group, an optionally substituted benzyl group, or an optionally substituted heterocycle.

Preferred examples of the general formula (5) include R ⁴¹
Represents a methyl group, R ⁴² represents a lower alkyl group, a benzyl group or a lower alkoxyalkyl group, R ⁴³ represents a hydrogen atom, R ⁴⁴ and R ⁴⁵ each independently represent a hydrogen atom, a fluorine atom, a chlorine atom , lower alkyl group, a trifluoromethyl group, a ³ group, or -COOX ³ group -OX, X ³ is a lower alkyl group, a lower alkoxyalkyl group, an optionally substituted phenyl group, optionally substituted Represents a benzyl group or an optionally substituted heterocycle. The quinophthalone-based yellow pigment used in the present invention is generally represented by the general formula (6).

[0034]

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In the general formula (6), R ⁵¹ represents a hydrogen atom or a lower alkyl group, preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ⁵² represents a hydrogen atom, a halogen atom, an alkoxy group, or an optionally substituted phenoxy group, preferably represents a hydrogen atom or a halogen atom, and more preferably represents a hydrogen atom or a bromine atom. E is -COOR ⁵³ group or -CONR ⁵⁴ R ⁵⁵
Represents a group. R ⁵³ represents an optionally substituted alkyl group, an optionally substituted lower alkenyl group, or an optionally substituted aryl group, preferably an optionally substituted alkyl group having 3 to 12 carbon atoms. Or a phenyl group which may be substituted, more preferably an alkyl group having 3 to 8 carbon atoms, or an alkoxyalkyl group having 3 to 8 carbon atoms in total.

R ⁵⁴ and R ⁵⁵ each independently represent a hydrogen atom, a lower alkyl group which may be substituted, a lower alkenyl group which may be substituted, or an aryl group which may be substituted. However, R ⁵⁴ and R ⁵⁵ are not simultaneously hydrogen atoms. Preferably, each of R ⁵⁴ and R ⁵⁵ independently represents an optionally substituted lower alkyl group or an optionally substituted aryl group. More preferably, R ⁵⁴ and R ⁵⁵ each independently represent a lower alkyl group. Examples of preferred formula (6), R ⁵¹ represents an alkyl group having 1 to 4 hydrogen or C, R ⁵²
Represents a hydrogen atom or a bromine atom, E represents a —COOR ⁵³ group or a —CONR ⁵⁴ R ⁵⁵ group, and R ⁵³ has 3 to 8 carbon atoms.
And R ⁵⁴ and R ⁵⁵ each represent a lower alkyl group.
The pyrazolone-based yellow dye used in the present invention is generally represented by the general formula (7).

[0037]

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In the general formula (7), R ⁶¹ represents an optionally substituted lower alkyl group, an optionally substituted lower alkenyl group or an optionally substituted aryl group, preferably an optionally substituted lower alkyl group. Represents an optionally substituted lower alkyl group or an optionally substituted aryl group. R ⁶²
Is an optionally substituted lower alkyl group, a di-lower alkylamino group (an alkyl group may be substituted),-
Represents a COOQ ¹ group or a -CONZ ¹ T ¹ group, and preferably represents an optionally substituted lower alkyl group or a di-lower alkylamino group (the alkyl group may be substituted). Q ¹ represents an optionally substituted lower alkyl group, an optionally substituted lower alkenyl group, or an optionally substituted aryl group. Z ¹ and T ¹
Each independently represents a hydrogen atom, a lower alkyl group which may be substituted, a lower alkenyl group which may be substituted, or an aryl group which may be substituted.

R ⁶³ represents a hydrogen atom or a lower alkyl group, preferably a hydrogen atom. G is an alkenyl group which may be substituted, an aryl group which may be substituted,
Or an optionally substituted pyrazolone group, preferably an optionally substituted alkenyl group, an optionally substituted aryl group, or an optionally substituted pyrazolone group. The pyrazolone-based yellow dye used in the present invention is preferably represented by the general formula (8).

[0040]

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In the general formula (8), R ⁷¹ and R ⁷² are each independently a lower alkyl group which may be substituted, a lower alkenyl group which may be substituted, an aryl group which may be substituted, or Represents a heterocyclic ring which may be substituted, preferably independently represents a lower alkyl group; a phenyl group which may be substituted with a lower alkyl group, a lower alkoxy group, a halogen atom or the like; or an aralkyl group, Preferably each independently represents a lower alkyl group; a phenyl group which may be substituted with a methyl group or a halogen atom; or a benzyl group, and more preferably each independently represents a methyl group, an ethyl group, a propyl group, a butyl group, Represents a phenyl group or a toluyl group.

R ⁷³ and R ⁷⁴ are each independently a lower alkyl group which may be substituted, a lower alkenyl group which may be substituted, an aryl group which may be substituted,
An optionally substituted heterocycle, a dialkylamino group (an alkyl group may be substituted), a -COOQ ² group,
Or an -CONZ ² T ² group, preferably each independently represent a lower alkyl group or -COOQ ² group,
More preferably each independently is a methyl group or -C
OOQ ² group. Q ² represents an optionally substituted lower alkyl group, an optionally substituted lower alkenyl group, or an optionally substituted aryl group, preferably a lower alkyl group, an optionally substituted phenyl group,
Or an aralkyl group, more preferably a lower alkyl group, a phenyl group which may be substituted with a methyl group or a halogen atom, or a benzyl group, further preferably an ethyl group, a propyl group, or a butyl group.

Z^TwoAnd T^TwoAre each independently a hydrogen source
A substituted or unsubstituted lower alkyl group,
An optionally substituted lower alkenyl group, or an optionally substituted
Represents a good aryl group. R⁷⁵Is a hydrogen atom,
A lower alkyl group which may be substituted;
A alkenyl group, an optionally substituted aryl group, or
Represents an optionally substituted heterocycle, preferably a hydrogen atom
Represents a child. Preferred examples of the general formula (8) include R⁷¹You
And R⁷²Are each independently a methyl group, an ethyl group,
Represents a pill, butyl, phenyl, or toluyl group.
Then R⁷³And R⁷⁴Are each independently a methyl group or
-COOQ^TwoRepresents a group, Q ^TwoIs an ethyl group, a propyl group,
Or represents a butyl group. R⁷⁵Represents a hydrogen atom. The present invention
The pyrazole-based yellow dye used in the above is usually represented by the general formula (9)
Indicated by

[0044]

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In the general formula (9), R ⁸¹ represents a lower alkyl group which may be substituted, a lower alkenyl group which may be substituted, or an aryl group which may be substituted. Represents an optionally substituted aryl group. R ⁸² represents an optionally substituted lower alkyl group, an optionally substituted lower alkenyl group, or an optionally substituted aryl group, preferably an optionally substituted lower alkyl group or an optionally substituted lower alkyl group; Represents an optionally substituted aryl group. R ⁸³ represents an optionally substituted lower alkyl group, a hydroxyl group, an amino group, a di-lower alkylamino group (an alkyl group may be substituted), —COOQ ³
It represents a group, or -CONZ ³ T ³ group, preferably a optionally substituted lower alkyl group, an amino group or a di-lower alkylamino group, (the alkyl group may be substituted).

Q ³ represents an optionally substituted lower alkyl group, an optionally substituted lower alkenyl group, or an optionally substituted aryl group. Z ³ and T ³
Each independently represents a hydrogen atom, a lower alkyl group which may be substituted, a lower alkenyl group which may be substituted, or an aryl group which may be substituted. J
Represents an alkenyl group which may be substituted or an aryl group which may be substituted, and preferably represents an aryl group which may be substituted. As a preferable example of the general formula (9), R ⁸¹ represents an optionally substituted aryl group, R ⁸² represents an optionally substituted lower alkyl group or an optionally substituted aryl group, ⁸³ represents an optionally substituted lower alkyl group, an amino group, or a di-lower alkylamino group (the alkyl group may be substituted). J represents an aryl group which may be substituted. The disazo yellow dye used in the present invention is generally represented by the general formula (10).

[0047]

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In the general formula (10), R ⁹¹ , R ⁹² and R ⁹³ each independently represent a hydrogen atom, a lower alkyl group which may be substituted, a lower alkenyl group which may be substituted, Optionally a lower alkoxy group,
Optionally substituted aryl group, hydroxyl group, nitro group,
Represents a cyano group, an optionally substituted acylamino group, an optionally substituted alkoxycarbonyl group, an optionally substituted alkylsulfonyl group, an optionally substituted sulfamoyl group, or a halogen atom. Preferably, R ⁹¹ , R ⁹² and R ⁹³ each independently represent a hydrogen atom, an alkyl group having 4 or less carbon atoms, an alkoxy group having 4 or less carbon atoms, a trifluoromethyl group, a hydroxyl group, a nitro group, a cyano group, an acetyl group. Represents an amino group, a propionyl group, a benzoyl group, a dimethylaminosulfonyl group, a fluorine atom, or a chlorine atom.

R ⁹⁴ , R ⁹⁵ , R ⁹⁶ , R ⁹⁷ , R ⁹⁸ , and R
⁹⁹ represent each independently a hydrogen atom, an optionally substituted lower alkyl group, optionally substituted lower alkenyl group, an optionally substituted lower alkoxy group, a halogen atom or a hydroxyl group,, R ⁹⁵ And R ⁹⁶ , and R ⁹⁸
And R ⁹⁹ may combine to form an optionally substituted ring. Preferably, R ⁹⁴ , R ⁹⁵ , R ⁹⁶ , R ⁹⁷ , R
⁹⁸ and R ⁹⁹ each independently represent a hydrogen atom, an alkyl group having 4 or less carbon atoms, an alkoxy group having 4 or less carbon atoms, or a hydroxyl group; R ⁹⁵ and R ⁹⁶ , and R ⁹⁸ and R ⁹⁹ are linked; To form an aromatic ring which may be substituted with an alkyl group having 4 or less carbon atoms, an alkoxy group having 4 or less carbon atoms, or a hydroxyl group.

Preferred examples of the general formula (10) include R
⁹¹ , R ⁹² and R ⁹³ each independently represent a hydrogen atom,
An alkyl group having 4 or less carbon atoms, an alkoxy group having 4 or less carbon atoms, a trifluoromethyl group, a hydroxyl group, a nitro group, a cyano group, an acetylamino group, a propionyl group, a benzoyl group, a dimethylaminosulfonyl group, a fluorine atom, or a chlorine atom Wherein R ⁹⁴ , R ⁹⁵ , R ⁹⁶ , R ⁹⁷ , R ⁹⁸ , and R ⁹⁹ each independently represent a hydrogen atom, an alkyl group having 4 or less carbon atoms, an alkoxy group having 4 or less carbon atoms, or a hydroxyl group . R ⁹⁵ and R ⁹⁶ , and R ⁹⁸ and R ⁹⁹ are linked to form an alkyl group having 4 or less carbon atoms, an alkoxy group having 4 or less carbon atoms, or an aromatic ring which may be substituted with a hydroxyl group. You may.

When a magenta color material layer is further provided as one of the color material layers, an anthraquinone dye, an imidazole azo dye, a thiadiazole azo dye, a benzene azo dye, or the like is preferably used as the magenta dye. It is possible to mix and use a plurality of types as necessary. The color material layer is usually applied to a substrate with an ink obtained by dissolving or dispersing a dye and a binder resin in a solvent,
It is formed by drying. In order to obtain a print having a high concentration, it is preferable that the dye and the binder resin are dissolved in a solvent. As the binder resin used for the color material layer, for example, a polycarbonate resin, a polysulfone resin, a polyvinyl butyral resin, a polyvinyl acetoacetal resin, a cellulose resin, a polyester resin,
Epoxy resin, phenoxy resin, polyarylate resin,
Polyamide resin, polyaramid resin, polyimide resin,
Examples thereof include polyetherimide resins and acrylonitrile / styrene copolymer resins. Preferably, a polycarbonate resin, a polyvinyl butyral resin, a polyvinyl acetoacetal resin, a cellulosic resin, a polyester resin, an epoxy resin, a phenoxy resin, and an acrylonitrile-styrene copolymer resin are used.

Examples of the solvent used for the ink include aromatic solvents such as toluene and xylene; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ester solvents such as ethyl acetate and butyl acetate; Alcohol solvents such as isopropanol and butanol; ether solvents such as methyl cellosolve, ethyl cellosolve, dioxane and tetrahydrofuran; amide solvents such as dimethylformamide and N-methylpyrrolidone. Among various solvents, tetrahydrofuran can be used particularly preferably because of its high dissolving power of a dye or resin, and tetrahydrofuran preferably contains an antioxidant. Further, these solvents may be used as a mixture of a plurality of types.

The ink contains, as necessary, other components of a dye and a binder, such as organic or inorganic non-sublimable particles, a dispersant, an antistatic agent, an antiblocking agent, an antifoaming agent, a plasticizer, and an oxidizing agent. Additives such as inhibitors and viscosity modifiers can be added. Further, an infrared absorber or carbon black may be added for use in a sublimation transfer system using laser light. There is no particular limitation on the method of applying the ink to the substrate, but a gravure coat, a gravure reverse coat, a roll coat, a die coat, or the like can be used. The coating film thickness is usually 0.1 to 5 μm, preferably 0.2 to 3 μm, more preferably 0.4 to 1.5 μm in dry film thickness.
m. If the dry film thickness is too small, a high-density image cannot be obtained, while if it is too thick, it may be difficult to sufficiently dry the film when applied.

The weight ratio of the binder resin to the dye in the color material layer is usually 3: 1 to 1: 3, preferably 2: 1 to 1: 2, and particularly preferably 1.5: 1 to 1: 1.5. . In general, the higher the ratio of the total weight of the dye to the weight of the binder resin in the color material layer, the higher the transfer sensitivity and the highest attainable density. However, if the dye weight is too large relative to the binder resin weight in order to obtain high sensitivity and high density, the color will not be obtained if the heat-sensitive transfer sheet with the heat-resistant active layer coated on the surface opposite to the color material layer is wound and stored. The material layer and the heat-resistant active layer may cause blocking. The heat-sensitive transfer sheet of the present invention preferably has a heat-resistant lubricating layer provided on the surface opposite to the color material layer. Although there is no particular limitation on the heat-resistant lubricating layer, for example, a layer using a thermoplastic resin having a high glass transition temperature, a layer using an ultraviolet curable resin or a thermosetting resin can be used. Also,
It is preferable to add a lubricant such as silicone oil in order to provide lubricity.

In the heat-sensitive transfer recording, the color material layer surface of the heat-sensitive transfer sheet of the present invention and the image-receiving surface of a recording material having an image-receiving layer preferably provided on one side of the substrate are superposed on each other. A method is generally used in which a heat source such as a line-type thermal head or a laser is used to apply heat in accordance with an image signal from the side opposite to the color material layer surface to transfer the dye in the color material layer to the image receiving layer. During recording, depending on the amount of heat applied,
Since the amount of the dye to be transferred can be changed, it is possible to express light and shade, and to obtain a fine image. yellow,
By repeating the same operation for three colors of magenta and cyan or four colors including black, a full-color photographic image can be obtained. As a thermal transfer sheet,
There are a method of using each color of cyan, yellow, and magenta as a separate thermal transfer sheet and a method of using a plane-sequential thermal transfer sheet.However, a method using a plane-sequential thermal transfer sheet is preferable to obtain an image. It is preferable because only one transfer sheet is required and the apparatus for performing the transfer is simplified. As a heat source for transferring the dye, a line type thermal head is generally used, but it is also known to use a laser beam. In that case, it is necessary to use a light-to-heat conversion material to convert the laser light into heat, and to use an infrared absorber or carbon black in the color material layer of the heat-sensitive transfer sheet.
It is known to be added between the color material layer and the base material or on the surface opposite to the color material layer.

It is preferable to provide a protective layer on a printing screen in a print using the thermal transfer sheet of the present invention. The protective layer is provided on the image for the purpose of protecting the image from contamination of the image due to finger oil, water, dust, etc., decomposition of the pigment due to moisture, air, etc., and damage to the image due to mechanical shock, etc. is there. The protective layer can be provided on the image by coating, but is preferably provided on the same side of the substrate of the thermal transfer sheet as the color material layer so as to be capable of thermal transfer. When the heat-sensitive transfer sheet of the present invention is provided with a heat-transferable protective layer on the same side as the colorant layer of the substrate, the protective layer is formed on the image by heating from the opposite side to the protective layer of the substrate. Can be provided. Either a sheet provided with only the protective layer on the base material or a sheet provided with a color material layer and a protective layer on the base material sequentially can be preferably used, but in the latter case, the sheet is continuously formed after image formation. It is simple and particularly preferable because a protective layer can be formed on an image with the same heat source. Providing a protective layer on an image has the advantage of improving the stability of the image.

Hereinafter, the case where the protective layer is provided on the base material so as to be capable of thermal transfer will be described. As the substrate on which the protective layer is provided, the same substrate as that used for providing the coloring material layer can be used. A release adjusting layer for adjusting the releasability of the protective layer may be provided on the surface on which the protective layer is provided. The protective layer preferably has a structure having at least two layers of a surface layer and an adhesive layer from the substrate side. It is preferable to provide a heat-resistant lubricating layer on the surface of the substrate opposite to the protective layer. The surface layer is made of various resins having excellent friction resistance, weather resistance, etc., for example, acrylic resin, polyurethane resin, polystyrene resin, polyester resin, acrylic urethane resin, silicone-modified resin of these resins, and a mixture of these resins. Can be used. Among these resins, acrylic resins are preferred.

Since these resins form a tough film, the edges of the resin are likely to be insufficiently cut at the time of transfer from the opposite surface of the substrate when heated. In order to improve this, fine particles such as silica or wax can be added to the surface layer. As a method of forming a surface layer on a substrate, a method similar to the method described in the case of forming a color material layer can be used. The thickness of the surface layer is usually 0.1 to 10 μm
And preferably about 1 to 5 μm. For the purpose of improving light resistance and weather resistance, a hindered amine-based light stabilizer, a benzotriazole-based, benzophenone-based, or benzoate-based ultraviolet absorber, a metal salt of an acid phosphate, and a fine particle inorganic pigment are added to the surface layer. Is preferred. Particularly preferred among these additives are ultraviolet absorbers. By adding an ultraviolet absorber, the surface layer, and thus the protective layer, can have ultraviolet absorption ability,
This is preferable because not only the light resistance of the protective layer but also the light resistance of the image can be improved. The amount of the ultraviolet absorber added is usually 0.01 to 20% by weight, preferably 0.1 to 20% by weight of the surface layer.
〜１０10%. The light transmittance of the ultraviolet part by addition is 30
It is preferably 3% or less at 0 nm. A plurality of additives may be used in combination.

Examples of hindered amine light stabilizers include those having a piperidine structure such as 2,2,6,6-tetramethylpiperidine or 1,2,2,6,6-pentamethylpiperidine as a partial structure. Preferably, for example, dimethyl succinate 1- (2-hydroxyethyl)
4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,
6,6-pentamethyl-4-piperidyl) sebacate,
(Poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} (2,2,6,6-tetramethyl-4- Piperidyl) imino {hexamethylene} (2,2,6,6-tetramethyl-4-piperidyl) imino}]).

As an example of an ultraviolet absorber, a benzotriazole-based ultraviolet absorber such as 2- (5-methyl-2-
(Hydroxyphenyl) benzotriazole, 2- [2-
Hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2-
(3,5-di-t-butyl-2-hydroxyphenyl)
Benzotriazole, 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chloro Benzotriazole, 2-
(3,5-di-t-amyl-2-hydroxyphenyl)
Benzotriazole, 2- (2'-hydroxy-5'-
t-octylphenyl) benzotriazole and the like, as benzophenone-based ultraviolet absorbers, 2,4-dihydroxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, -Hydroxy-4-methoxybenzophenone, pt-butylphenyl salicylate-2-hydroxy-4-methoxybenzophenone and the like, and 2,4-di-t-butylphenyl-3 ′, 5 as a benzoate-based ultraviolet absorber. '-Di-t-butyl-
4'-hydroxybenzoate, pt-butylphenyl-salicylate and the like can be mentioned.

Examples of the metal salts of acidic phosphates include stearyl acid phosphate, magnesium stearyl phosphate, aluminum stearyl phosphate, calcium stearyl phosphate, zinc stearyl phosphate, barium stearyl phosphate, and the like. Examples of the fine particle inorganic pigment include zinc oxide, tin oxide-based conductive fine powder, titanium oxide, and TiO _2.
• SnO ₂ (Sb-doped), barium sulfate-based conductive powder, and the like. The adhesive layer mainly contains a resin having good heat adhesion such as an acrylic resin, a vinyl chloride resin, a polyester resin, a vinyl acetate resin, a vinyl chloride-vinyl acetate copolymer resin, a polyamide resin, and a silicone resin. The same additives as those for the surface layer may be added as additives. The adhesive layer is formed on the surface layer by coating and drying a solution of a resin or an additive, preferably in a thickness of about 0.1 to 5 μm, in the same manner as the formation of the surface layer. .

When performing thermal transfer recording, the recording material used together with the thermal transfer sheet of the present invention is not particularly limited.
Preferably, the recording material has an image receiving layer provided on at least one surface of a substrate. The base material of the recording material is synthetic paper,
Cellulose paper, cast coated paper, synthetic resin film,
A card made of synthetic resin, a base material in which synthetic paper or a synthetic resin film is attached to both sides of cellulose paper, or the like is used.
Since the higher the adhesion to the color material layer, the more uniform the transfer of the dye during recording is, the surface is preferably smooth, and if possible, a substrate having a Beck smoothness of 10,000 seconds or more should be used. preferable. From this point, synthetic paper, synthetic resin film, cellulose / synthetic paper bonding substrate, cellulose /
A synthetic resin film bonding substrate and a substrate using a card are preferable.

The image receiving layer is a layer mainly composed of a resin, and has a role of forming an image by receiving a dye. As the resin, a resin which easily dyes a dye is preferable. For example, vinyl acetate resin, vinyl chloride resin, vinyl chloride / vinyl acetate copolymer resin, cellulose resin, polyester resin, acrylonitrile / styrene copolymer resin, polycarbonate resin, polyvinyl acetal resin and the like can be mentioned. These can be used by mixing and copolymerizing. These resins preferably have a high glass transition point, for example, 100 ° C. or higher. If a resin having a glass transition point that is too low is used, the image may bleed during storage. Additives can be added to the image receiving layer, if necessary, in addition to the resin. Examples of the additive include, but are not limited to, a curing agent such as an isocyanate for curing a resin, and a release agent such as a silicone added for preventing fusion with a coloring material layer during thermal transfer. . An anchor coat for improving adhesiveness may be provided between the image receiving layer and the substrate.

After forming an image on the image receiving layer using a transparent film as the base material of the recording material, the surface of the image receiving layer is pressed against another opaque base material, and the image is viewed through the transparent film of the base material. It is also possible to use a method in which the transparent film itself serving as a base serves as a protective layer. In this case, it is preferable that the transparent film contains additives such as an ultraviolet absorber and an antioxidant. There is a method in which an image receiving layer is formed on a substrate of a recording material so as to be peelable, and the peelable image receiving layer is used as an intermediate recording layer. In this case, after forming an image on the intermediate recording layer,
The intermediate recording layer is pressed against the surface of another final recording material, the base material is peeled off, the intermediate recording layer is left on the final recording material, and the image is viewed through the intermediate image receiving layer. It acts as a protective layer. In this case, the intermediate recording layer preferably contains additives such as an ultraviolet absorber and an antioxidant. In the present invention, "lower" means having 1 to 8 carbon atoms, and as the substituent which may be substituted, an alkyl group includes an alkoxy group, an alkoxyalkoxy group, a halogen atom, a hydroxyl group, a cyano group, an amino group, Heterocycle, aryl group, alkenyl group, aralkyl group, and the like.In the alkenyl group, the aryl group, and the aralkyl group, an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, a cyano group, an amino group, a heterocycle, and the like. No. In the present invention, λmax means a wavelength at which absorption is maximum between 400 and 700 nm when measured in a toluene solution.

[0065]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. Unless otherwise specified below, “%” and “parts” represent “% by weight” and “parts by weight”, respectively.

<Examples 1 to 4 and Comparative Examples 1 to 4> (a) Preparation of Cyan Thermal Transfer Sheet The dyes A, B and C shown in Table 1 were used in parts by weight shown in Table 1 and polyvinyl butyral resin (product) Name: BX-1, manufactured by Sekisui Chemical Co., Ltd.) 100 parts, tetrahydrofuran 1200 parts,
1000 parts of toluene and 200 parts of cyclohexanone were mixed and stirred to completely dissolve the dye and the resin, thereby preparing an ink. This ink was applied to a 6 μm-thick polyester film using a bar coater so as to have a dry film thickness of 0.8 μm, and dried to form a cyan color material layer. Acrylic resin (trade name: BR-100, manufactured by Mitsubishi Rayon Co., Ltd.), 10 parts, amino-modified silicone oil (trade name: KF-) on the back surface of the substrate (the surface of the polyester film on which the cyan material layer is not formed) 393, manufactured by Shin-Etsu Chemical Co., Ltd.) and 89 parts of toluene were applied using a bar coater to a dry film thickness of 1 μm and dried to form a heat-resistant lubricating layer.

(B) Preparation of Recording Material (Receiver) 65 parts of polyvinyl phenyl acetal resin, vinyl chloride / vinyl acetate / vinyl alcohol copolymer resin (trade name:
35 parts of VAGD, manufactured by Union Carbide Co., Ltd., 15 parts of silicone varnish for modification (trade name: TSR-160, solid content concentration: 60%, manufactured by Toshiba Silicone Co., Ltd.), hexamethylene diisocyanate-based polyfunctional isocyanate compound (product) Name: Mytec NY-710A, solid content concentration 7
6%, 5% amino-modified silicone oil (trade name: KF393, Shin-Etsu Chemical Co., Ltd.)
One part, 300 parts of methyl ethyl ketone and 300 parts of toluene were mixed and stirred to prepare a coating solution. This coating solution was applied to a 150 μm-thick polypropylene synthetic paper (trade name: Yupo F
PG150, manufactured by Oji Yuka Synthetic Paper Co., Ltd.) was applied with a wire bar, dried (dry film thickness: about 5 μm), and further heat-treated in an oven at 60 ° C. for 48 hours to produce an image receiving body. The above polyvinyl phenyl acetal resin is polyvinyl alcohol (a degree of saponification of 99 mol%, a degree of polymerization of 170).
0) was obtained by acetalization with phenylacetaldehyde, and had a structure represented by the following formula.

[0068]

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(C) Thermal transfer recording (cyan printing) The color material layer surface of the thermal transfer sheet having the cyan color material layer obtained in (a) and the resin-coated surface of the image receiving body obtained in (b) are used. Overlap, a partial grace type line thermal head having a heating resistor density of 5.6 dots / mm is applied to the surface of the heat-resistant lubricating layer, and 13 lines at 6 lines (dots) / mm in the feed direction.
Printing was performed at an applied power of 0.20 W / dot at a speed of s / line. Printing was performed with the time applied to the head per line being 9 ms.

(D) Measurement of Print Density and Hue The density of the print obtained in (c) was measured using a spectrophotometer (trade name:
(SPM-50, manufactured by Gretag). A DIN-NB filter was used as a filter. Also,
A print sample was prepared in the same manner as in (c) except that the application time per line was set to 6 ms, and the hue angle in the CIELAB color space was measured using the above-mentioned spectrophotometer (the hue angle was arctan (b) ^* / A ^* ) and a ^*
<0, b ^* <0, it is determined to be 180 to 270 degrees). The observation conditions at this time were a D50 light source and a viewing angle of 2 degrees, and the density of the sample for which the hue angle was measured was about 1.0 in all samples. Table 2 shows the results.

(E) Stability test 1 of printed matter (Crystal precipitation 1 from printed matter) After the printed matter obtained in (c) was allowed to stand at room temperature for 4 months, the surface was examined with a microscope of 200 times magnification. Observation was made to determine whether crystals had precipitated. Table 2 shows the results. (F) Stability test 2 of printed matter (Crystal precipitation 2 from printed matter) The surface of the printed matter obtained in (c) was obtained from a market by using an image receiver (trade name: VW-MPA50 Matsushita Electric Industrial Co., Ltd.) )
The surface of the print was finely scratched by rubbing lightly on the back side (non-printed screen), and after further storing at 45 ° C. for 2 weeks, the surface was observed under a microscope at 200 × magnification. It was examined whether or not it had precipitated. Table 2 shows the results
Shown in

[0072]

[Table 1]

Dye 1-1: (In the general formula (1) represented by the following formula, -A- is -NHCOO, R ¹ ,
A dye in which R ² and R ³ are an ethyl group, R ⁴ and R ⁵ are a methyl group, and X1 is a chlorine atom. λmax is 641n
m)

[0074]

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Dye 1-2: (In the general formula (1) represented by the following formula, -A- is -NHCO-, R ¹ is a methyl group, R ² and R ³ are ethyl groups, R ⁴ and R ^A dye in which ⁵ is a methyl group and X1 is a chlorine atom, and λmax is 647n.
m)

[0076]

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Dye 1-3: (In the general formula (1) represented by the following formula, -A- is -NHCO-, R ¹ is a methyl group, R ² and R ³ are n-butyl groups, R ⁴ And a dye in which R ⁵ is a methyl group and X ¹ is a chlorine atom.
2 nm)

[0078]

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Dye 2: (General formula (2) represented by the following formula:
In the above, -D- is -NHCO-, R¹¹Is a benzyl group,
R¹²And R¹³Is an ethyl group, R¹⁴Is a methyl group, R¹⁵And
And X ^TwoIs a hydrogen atom. 555nm to 635n
m is 608 nm).

[0080]

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Dye 3: General formula (3) represented by the following formula
In, R^{twenty one}And R^{twenty two}Is C_TwoH _FourO-nC_FourH₉so
Yes, R^{twenty three}Is NHCOCH_ThreeAnd R^{twenty four}Is a hydrogen atom
A certain dye. Absorption peak between 555 nm and 635 nm
Is 573 nm)

[0082]

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Dye 4: (Formula (4) represented by the following formula:
In the dye, R ³¹ is a methyl group, and R ³² is an m-toluyl group. (The absorption peak between 555 nm and 635 nm is 600 nm.)

[0084]

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[0085]

[Table 2]

In Table 2, た だ し indicates no crystal precipitation,
△ indicates slight precipitation of crystal, △ × indicates moderate precipitation of crystal, ×
Is a large number of crystal precipitations, xx is a very large number of crystal precipitations,
Means

<Example 5, Comparative Example 5> (g) Preparation of Yellow Thermal Transfer Sheet No. 1 Dye 5 (in the general formula (5), R⁴¹Is a methyl group, R⁴²
Is an n-butyl group, R⁴³And R⁴⁴Is a hydrogen atom, R⁴⁵But salt
25 parts of a dye of an elemental atom, dye 6 (in the general formula (6)
And R⁵¹Is a hydrogen atom, R⁵²Is a bromine atom, -E- is -CO
NR⁵⁴R⁵⁵-, R ⁵⁴And R⁵⁵Is a propyl group dye) 3
0 parts, dye 7 (in the general formula (8), R ⁷¹And R⁷²
Is a phenyl group, R⁷³And R⁷⁴Is a methyl group, R⁷⁵Is hydrogen
35 parts of atomic dye, polyvinyl butyral resin (product)
Name: BX-1, 100 parts by Sekisui Chemical Co., Ltd., Tetrahi
1200 parts of drofuran, 1000 parts of toluene, cyclohexane
Mix and stir 200 parts of xanone to completely dissolve dye and resin
To make a yellow ink.

The yellow ink was applied to a 6 μm-thick polyester film with a dry film thickness of 0.8 μm using a bar coater.
m, and dried to form a yellow color material layer.
Acrylic resin (trade name: BR-10) on the back surface of the substrate (the surface of the polyester film on which the yellow color material layer is not formed)
0, manufactured by Mitsubishi Rayon Co., Ltd.), 10 parts, amino-modified silicone oil (trade name: KF-393, Shin-Etsu Chemical Co., Ltd.)
1 part) and 89 parts of toluene were applied using a bar coater to a dry film thickness of 1 μm and dried to form a heat-resistant lubricating layer. (H) Preparation of Yellow Thermal Transfer Sheet No. 2 In the same manner as in (g) except that 60 parts of the following dye 8 was used instead of the mixture of dyes 5, 6, and 7 in (g) above A yellow thermal transfer sheet 2 was prepared. Dye 8:

[0089]

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(I) Preparation of thermal transfer sheet with protective layer Acrylic resin (BR-100, manufactured by Mitsubishi Rayon) 80
Part, ultraviolet ray absorbent (2- (3,5-di-t-butyl-
2-Hydroxyphenyl) benzotriazole, trade name: TINUVIN320 Ciba-Geigy Japan
5 parts, 40 parts of methyl ethyl ketone and 40 parts of toluene were stirred to obtain a coating liquid having a thickness of 6 with a peeling property.
Coating on polyester film of μm, dry thickness 2μm
Was formed. An acrylic resin emulsion (trade name: Polysol AT201) was formed thereon as an adhesive layer.
1, a methyl ethyl ketone solution of Showa Polymer Co., Ltd.) was provided with a protective layer having a dry thickness of 3 μm in total including the surface layer. A heat-resistant lubricating layer was formed on the surface of the polyester film opposite to the protective layer in the same manner as in (a).

(J) Light fastness test (printing of green color, transfer of protective layer) Using the yellow heat-sensitive transfer sheets 1 and 2 prepared in (g) and (h) in place of the cyan heat-sensitive transfer sheet, 6
A yellow print was prepared in the same manner as in (c) except that the time was set to ms / line. A green print was obtained by superimposing the cyan color material layer of the cyan thermal transfer sheet of Example 1 prepared in (a) from above the yellow print (application time: 6 ms) (without a protective layer). Green). The green print was further overlapped so that the printing screen and the adhesive layer of the protective layer prepared in (i) were in contact with each other, and heated from the surface of the heat-resistant lubricating layer using the above-described thermal head (application time: 9 ms). The image and the protective layer were adhered. Then, by peeling the base material of the protective layer,
An image having a protective layer formed on the surface was obtained (green with protective layer). The printed matter (green without a protective layer, green with a protective layer) obtained in this way was used as a light resistance tester (trade name: Xenon fade meter FAL-25A) using a xenon lamp.
X, manufactured by Suga Test Machine Co., Ltd.), and the CIEL of the printed matter before the test and that after the test was performed for 80 hours.
The AB color difference (ΔE) was measured using a spectrophotometer (trade name: SPM-5).
0, manufactured by Gretag Corporation) using a C light source and a viewing angle of 2 degrees. Table 3 shows the results.

[0092]

[Table 3]

As is clear from the results in Table 2, the heat-sensitive transfer sheet of the present invention gives a high density greenish cyan image,
Under various conditions, the images show that crystals are extremely unlikely to precipitate. Furthermore, from the results in Table 3, it can be seen that the green image formed using the heat-sensitive transfer sheet of the present invention has extremely good light fastness.

[0094]

According to the present invention, a green image having a high density and a green tint can be obtained by thermal transfer, and an image having extremely good image storage stability can be provided.

──────────────────────────────────────────────────の Continued on the front page (51) Int. Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C09B 29/42 C09B 29/42 A 31/02 31/02 53/02 53/02 (72) Inventor Morishima Takashi 1000, Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa F-term in Yokohama Research Laboratory, Mitsubishi Chemical Corporation 2H111 BA03 BA08 BA38 BA41 BA43 BA47 BA49 BA74 4H056 AA01 AB03 AD24B AD25B DD06

Claims (10)

[Claims] 1. A thermal transfer sheet having a cyan color material layer provided on at least one surface of a substrate, wherein the cyan color material layer contains at least two types of dyes represented by the following general formula (1). In the thermal transfer sheet, the λma of these dyes
x is 635-685 nm, and the total number of carbon atoms of the substituent represented by R ¹ of each of these dyes is 3 or more. Embedded image (Wherein -A- is -NHCO-, -NHCOO-, -C
Represents ONH— or —CONR ⁶ —, wherein R ⁶ is an optionally substituted alkyl group, an optionally substituted lower alkenyl group, an optionally substituted aryl group, an optionally substituted aralkyl group Or a heterocyclic ring which may be substituted with an alkyl group or a halogen atom. R ¹ is an optionally substituted alkyl group, an optionally substituted lower alkenyl group, an optionally substituted aryl group, an optionally substituted aralkyl group, or an alkyl group or a halogen atom. And R ² and R ³ each independently represent
Represents an alkyl group which may be substituted, R ⁴ represents a hydrogen atom or a lower alkyl group which may be substituted,
R ⁵ represents a hydrogen atom or a lower alkyl group which may be substituted, and X ¹ represents a hydrogen atom or a halogen atom. X ¹ may be linked to R ⁴ to form an optionally substituted ring. ) 2. The thermal transfer sheet according to claim 1, wherein in the general formula (1), at least one dye in which X ¹ is a halogen atom is contained. 3. The heat-sensitive transfer sheet according to claim 1, wherein in the general formula (1), R ⁵ contains at least one dye which is an alkyl group which may be substituted. 4. A heat-sensitive transfer sheet having a cyan color material layer provided on at least one surface of a substrate, wherein the cyan color material layer has at least two kinds of dyes having λmax of 635 to 685 nm and 555 to 635 nm. A thermal transfer sheet comprising at least one dye having an absorption peak. 5. The heat-sensitive transfer sheet according to claim 1, further comprising at least one dye having an absorption peak at 555 to 635 nm. 6. The dye having an absorption peak at 555 to 635 nm is a dye selected from the group consisting of the following general formulas (2), (3) and (4). 6. The heat-sensitive transfer sheet according to 4 or 5. Embedded image (Wherein -D- is -NHCO-, -NHCOO-, -C
Represents ONH— or —CONR ¹⁶ —, wherein R ¹⁶ is an optionally substituted alkyl group, an optionally substituted lower alkenyl group, an optionally substituted aryl group, an optionally substituted aralkyl group Or a heterocyclic ring which may be substituted with an alkyl group or a halogen atom. R ¹¹ is an optionally substituted alkyl group, an optionally substituted lower alkenyl group, an optionally substituted aryl group, an optionally substituted aralkyl group, or an alkyl group or a halogen atom. R ¹² and R ¹³ each independently represent
Represents an alkyl group which may be substituted, R ¹⁴ represents a hydrogen atom or a lower alkyl group which may be substituted,
R ¹⁵ represents a hydrogen atom or a lower alkyl group which may be substituted, and X ² represents a hydrogen atom or a halogen atom. X ² may be linked to R ¹⁴ to form an optionally substituted ring. ) (Wherein, R ²¹ and R ²² are each independently a lower alkyl group which may be substituted, a lower alkenyl group which may be substituted, an aryl group which may be substituted, or a substituent which may be substituted. Represents an aralkyl group, R ²¹ and R ²² may combine to form a ring, R ²³ represents a hydrogen atom, a halogen atom, a lower alkyl group which may be substituted, a lower alkenyl which may be substituted; Group, an optionally substituted lower alkoxy group, formylamino group,
Represents an optionally substituted lower acylamino group, an optionally substituted lower alkylsulfonylamino group, or a lower alkoxycarbonylamino group, wherein R ²⁴ is a hydrogen atom, a halogen atom, an optionally substituted lower alkyl group, And represents an optionally substituted lower alkoxy group or an optionally substituted lower alkenyl group. ) (Wherein, R ³¹ and R ³² each independently represent a hydrogen atom,
A lower alkyl group which may be substituted, a lower alkenyl group which may be substituted, a cycloalkyl group which may be substituted, an aryl group which may be substituted, or a heterocyclic group which may be substituted; Represent. ) 7. The thermal transfer according to claim 1, wherein the hue angle of the print when the cyan color material layer is printed on the recording material is 210 to 245 degrees. Sheet. 8. A yellow color material layer is provided on at least one surface of a substrate, and the yellow color material layer is formed of a pyridone yellow dye, a quinophthalone yellow dye, a pyrazolone yellow dye, a pyrazole yellow dye, and a disazo yellow dye. The heat-sensitive transfer sheet according to any one of claims 1 to 7, further comprising at least one yellow dye selected from the group consisting of yellow dyes. 9. The yellow colorant layer according to claim 8, wherein the yellow colorant layer contains at least one yellow pigment selected from the group consisting of a pyridone yellow pigment, a quinophthalone yellow pigment, and a pyrazolone yellow pigment. Thermal transfer sheet. 10. The heat-sensitive transfer sheet according to claim 1, wherein a heat transferable protective layer is provided on at least one surface of the substrate.