JPH07266718A - Thermal transfer sheet - Google Patents

Abstract

PURPOSE:To provide a thermal transfer sheet capable of obtaining a high density yellowish record good in light fastness by low energy and capable of obtaining a high density black color by a color mixture of magenta and cyan by adding a specific dis-azo dye and a specific pyridone azo dye to a colorant layer. CONSTITUTION:In a thermal transfer sheet wherein at least a colorant layer is provided on a base material, a binder composed of a resin, a dis-azo dye represented by the formula I and a pyridone azo dye represented by the formula II are added to the colorant layer. In the formula I, X<1>-X<3> are a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, a nitro group, a cyano group, an acylamino group, an alkoxycarbonyl group, an alkylsulfonyl group, a substituted or non-substituted sulfamoyl group, a trifluoromethyl group or a halogen atom and Y<1>-Y<6> are a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom or a hydroxy group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive transfer recording sheet used for heat-sensitive transfer recording, particularly dye transfer type heat-sensitive transfer recording.

[0002]

2. Description of the Related Art A dye-transfer type heat-sensitive transfer recording is a heat-sensitive transfer sheet in which a heat-sensitive transfer sheet having a color material layer containing a heat transferable dye on a base film and an image-receiving sheet having a dye-receiving layer on the surface are superposed. Is a recording method in which recording is performed by transferring the dye in the heat-sensitive transfer sheet to the image-receiving sheet by heating. In this recording method, the transfer amount of the dye can be controlled by the amount of heating energy, so that gradation expression, which is difficult with other recording methods, can be easily performed.
Therefore, a full-color image can be easily produced by using the three primary color dyes of yellow, magenta and cyan dyes, and it is applied to a video printer and the like.

[0003]

In dye transfer type thermal transfer recording, the dye used in the ink composition of the transfer sheet has a great influence on the speed of transfer recording, the image quality of recorded matter, storage stability, etc. Is important, and it is necessary to satisfy the following conditions, for example. Easy sublimation and / or heat diffusion under the operating conditions of the thermal recording head. Do not decompose under the operating conditions of the thermal recording head. It should have a favorable hue for color reproduction. Large molecular extinction coefficient. Stable against heat, light, moisture, chemicals, etc. Easy to synthesize. Excellent ink suitability. There are no safety issues.

However, a dye satisfying all the above conditions has not been found so far, and a yellow dye, in particular, has various drawbacks. For example, in the present invention, the disazo dye represented by the general formula (I) has excellent characteristics in the above ,,,,, etc., but has a wide absorption spectrum and a long wavelength of the absorption spectrum. The hem on the side is bad, 550n
Since it has a weak absorption up to around m, the color purity as a yellow color is poor and there is a problem in color reproduction.

In the present invention, the pyridone azo dye represented by the general formula (II) is the above-mentioned ,,
It has excellent characteristics in ,, and so on. Further, since the absorption spectrum width is narrow and sharp, it is possible to reproduce a yellow color having excellent color purity. However, since the absorption spectrum width is narrow and sharp, when expressing a black color by mixing with a magenta dye and a cyan dye, in the absorption spectrum of the mixed color, the absorption near the boundary between the absorption of the yellow dye and the magenta dye. There is a gap. Therefore, when a black color is expressed using the yellow dye represented by the general formula (II), it is difficult to express a black color having a high color density. Further, the dye represented by the general formula (II) has a drawback that the light resistance is insufficient.

Further, since the correlation between the dye structure and various required performances as described above is not clear, it is difficult to predict the performance obtained when the dyes are used in combination, and the composition was actually prepared. It is necessary to select a good combination from among them. As a result of intensive studies to solve such problems, the present inventors have developed a coloring material layer containing a disazo dye and a dicyanovinyl dye having a specific skeleton selected from various possible combinations of dyes. By carrying out heat-sensitive transfer recording using a yellow-colored heat-sensitive transfer sheet having, it is possible to obtain a low-energy, high-concentration medium-yellow recorded material, and also to obtain a high-concentration mixture of magenta and cyan. The inventors have found that a black color can be obtained, and that the obtained recorded matter has very good light resistance in both the yellow color and the black color, and have reached the present invention.

That is, an object of the present invention is to obtain a low-energy, high-concentration medium-yellow recorded material,
Further, a yellow color heat-sensitive transfer sheet capable of obtaining a high-concentration black color by mixing with magenta and cyan and having very good light resistance in both the yellow color and the black color of the obtained recorded matter. To provide.

Therefore, the object of the present invention is to provide a heat-sensitive transfer sheet having at least a color material layer on a substrate,
A resin binder in the color material layer, a disazo dye represented by the following general formula (I), and

[0009]

[Chemical 4]

(Wherein X ¹ , X ² and X ³ are each a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group,
It represents a nitro group, a cyano group, an acylamino group, an alkoxycarbonyl group, an alkylsulfonyl group, a substituted or unsubstituted sulfamoyl group, a trifluoromethyl group or a halogen atom, and represents Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom or a hydroxy group, or Y ⁶
And Y ² and Y ⁴ and Y ⁵ may be linked to each other to form an aromatic ring structure. ) Pyridone azo dyes represented by the following general formula (II)

[0011]

[Chemical 5]

(Wherein R ¹ represents a hydrogen atom, a substituted or unsubstituted alkyl group, an alkenyl group, a cycloalkyl group or a substituted or unsubstituted phenyl group, Z represents a hydrogen atom or a methyl group,

[0013]

[Chemical 6] Represents a benzene ring which may have a nonionic substituent. ) Is easily achieved by a heat-sensitive transfer sheet characterized by containing a). Hereinafter, the present invention will be described in detail.

The disazo dye represented by the general formula (I) used in the present invention can be produced by a conventionally known method. In the general formula (I), X ¹ , X
² and X ³ are each a hydrogen atom; an alkyl group such as a methyl group, an ethyl group, a linear or branched propyl group or a butyl group; a methoxy group, an ethoxy group, a linear or branched propoxy group , Alkoxy group such as butoxy group; hydroxy group; nitro group; cyano group; trifluoromethyl group; acylamino group such as acetylamino group, propionyl group, benzoyl group; methoxycarbonyl group,
An alkoxycarbonyl group such as an ethoxycarbonyl group, a linear or branched propoxycarbonyl group, a butoxycarbonyl group; a methylsulfonyl group, an ethylsulfonyl group, a linear or branched propylsulfonyl group, a butylsulfonyl group, etc. Alkylsulfonyl group; Substitution and substitution of sulfamoyl group, methylaminosulfonyl group, ethylaminosulfonyl group, dimethylaminosulfonyl group, diethylaminosulfonyl group, linear or branched dipropylaminosulfonyl group, dibutylaminosulfonyl group, etc. A sulfamoyl group of: a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, wherein Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ are
Respectively hydrogen atom; alkyl group such as methyl group, ethyl group, linear or branched propyl group, and butyl group; alkoxy such as methoxy group, ethoxy group, linear or branched propoxy group, butoxy group, etc. Group; hydroxy group; represents a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or Y ¹ and Y ² and Y ⁴ and Y ⁵ are connected to each other to form an aromatic ring structure such as a benzene ring. You may form.

Preferred X ¹ , X ² and X ³ are hydrogen atom, hydroxy group, chlorine atom, fluorine atom, cyano group, ethoxy group, methoxy group, nitro group, trifluoromethyl group, dimethylaminosulfonyl group, Methyl group, ethyl group, acetylamino group,
Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ each represent a hydrogen atom, a methyl group, an ethyl group, a methoxy group, an ethoxy group or a hydroxy group, or Y ^1, Y ² and Y ⁴ And Y ⁵ are linked to each other to form a benzene ring.

In the present invention, the pyridoneazo dye represented by the general formula (II) can be produced by a conventionally known method. In the general formula (II),
R ¹ represents a hydrogen atom, a substituted or unsubstituted alkyl group, an alkenyl group, a cycloalkyl group or a substituted or unsubstituted phenyl group, Z represents a hydrogen atom or a methyl group, and A represents a nonionic substituent. Represents a benzene ring which may have.

R ¹ is a C1 to C12 linear or branched alkyl group; an alkoxy group, an amino group, an alkylamino group, an alkoxyalkoxy group, an aryloxy group, an allyloxy group, an aralkyloxy group,
Aryl group, cyano group, hydroxy group, halogen atom,
C1-C12 linear or branched alkyl group substituted with a furyl group, a tetrahydrofuryl group, an alkoxycarbonyl group, an allyloxycarbonyl group, an acyloxy group or the like; a cycloalkyl group; an alkenyl group; a substituted or unsubstituted group An aryl group such as a phenyl group; and a hydrogen atom.

Specific examples of the substituted alkyl group include an alkyl group substituted with an alkoxy group, 2-methoxyethyl group, 2-ethoxyethyl group, 2- (n) propoxyethyl group, 2- (iso). Propoxyethyl group,
2- (n) butoxyethyl group, 2- (iso) butoxyethyl group, 2- (sec) butoxyethyl group, 2-
(N) Pentyloxyethyl group, 2- (n) hexyloxyethyl group, 2- (n) octyloxyethyl group, 2
-(2'-ethylhexyloxy) ethyl group, 1-methyl-2-methoxyethyl group, 1-methyl-2-ethoxyethyl group, 1-methyl-2- (n) propoxyethyl group, 1-methyl-2- (Iso) propoxyethyl group,
1-methyl-2- (n) butoxyethyl group, 1-methyl-2- (iso) butoxyethyl group, 1-methyl-2-
(N) Hexyloxyethyl group, 1-methyl-2-
(2'-Ethylhexyloxy) ethyl group, 3-methoxybutyl group, 3-ethoxybutyl group, 1-ethyl-2-
Examples thereof include a methoxyethyl group and a 1-ethyl-2-ethoxyethyl group, and a C3-C8 β-alkoxyethyl group is particularly preferable. Examples of the alkyl group substituted with an amino group or an alkylamino group include 2-aminoethyl group, 2
-(N, N-diethylamino) ethyl group, 2- {N, N
Examples thereof include a -di (n) butylamino} ethyl group, a 3- (N, N-diethylamino) propyl group, and a 3- (N, N-dimethylamino) propyl group. Examples of the alkyl group substituted with an aralkyloxy group include a 2-benzyloxyethyl group, a 1-methyl-benzyloxyethyl group, 1
Examples include -ethyl-2-benzyloxyethyl group and 2- (β-phenylethyl) oxyethyl group. Examples of the alkyl group substituted with an allyloxy group include a 2-allyloxyethyl group, a 1-methyl-2-allyloxyethyl group, and a 1-ethyl-2-allyloxyethyl group. Examples of the alkyl group substituted with an aryloxy group include a 2-phenoxyethyl group, a 1-methyl-2-phenoxyethyl group and a 1-ethyl-2-phenoxyethyl group. Examples of the alkyl group substituted with an alkoxyalkoxy group include a 2- (2'-methoxyethoxy) ethyl group, a 2- (2'-ethoxyethoxy) ethyl group, and a 2- {2 '-(n) butoxyethoxy} ethyl group. ,
2- {2 '-(n) hexyloxyethoxy} ethyl group, 2- {2'-(n) octylethoxy} ethyl group,
2- {2 '-(iso) butoxyethoxy} ethyl group,
1-methyl-2- (2'-methoxyethoxy) ethyl group, 1-methyl-2- {2 '-(n) butoxyethoxy} ethyl group, 3- (2'-methoxyethoxy) butyl group and the like. Is particularly C5-C10 β- (β '
The -alkoxyethoxy) ethyl group is preferred. Examples of the alkyl group substituted with a cyano group include 2-cyanoethyl group and cyanomethyl group, and examples of the alkyl group substituted with a hydroxy group include 2-hydroxyethyl group, 3-hydroxy (n) propyl group and 4-hydroxy group. (N) A butyl group, a 1-methyl-2-hydroxyethyl group, a 1-ethyl-2-hydroxyethyl group or the like is a 2-chloroethyl group, 2-
A bromoethyl group, a 2,2,2-trifluoroethyl group or the like is a furfuryl group as an alkyl group substituted with a furyl group, and a tetrahydrofurfuryl group is an aryl group as an alkyl substituted with a tetrahydrofuryl group. Examples of the alkyl group substituted with include a benzyl group, a p-chlorobenzyl group, a 2-phenylethyl group, and the like. Examples of the alkyl group substituted with an alkoxycarbonyl group or an allyloxycarbonyl group include 2-methoxycarbonylethyl group, 2-ethoxycarbonylethyl group, 2
-(Iso) butoxycarbonylethyl group, 2- (n)
Hexyloxycarbonyl group, 1-methyl-2-methoxycarbonylethyl group, 1-methyl-2 (n) butoxycarbonylethyl group, 2-allyloxycarbonylethyl group, 1-methyl-2-allyloxycarbonylethyl group, methoxy Carbonylmethyl group, ethoxycarbonylmethyl group, (iso) butoxycarbonylmethyl group,
(N) Hexyloxycarbonylmethyl group, 2-ethylhexyloxycarbonylmethyl group and the like.
As the alkyl group substituted with an acyloxy group, a 2-acetoxyethyl group, a 2-propionyloxyethyl group,
2-benzoyloxyethyl group, 3-acetoxy (n)
Examples thereof include a propyl group, 4-acetoxy (n) butyl group, 1-methyl-2-acetoxyethyl group, 1-ethyl-2-acetoxyethyl group.

Examples of the cycloalkyl group represented by R ¹ include a cyclopentyl group and a cyclohexyl group. When R ¹ is a substituted phenyl group, the substituent may be a C1-C4 lower alkyl group, C1-C
4, lower alkoxy group, halogen atom such as fluorine atom, chlorine atom, bromine atom, and trifluoromethyl group.

Examples of the alkenyl group represented by R ¹ include allyl group and vinyl group. Among the groups represented by R ¹ , particularly preferable are C1 to C8 linear or branched alkyl groups, C3 to C8 alkoxyalkyl groups, benzyl groups, 2-phenylethyl groups, and allyl groups. And so on. Also, the above

[0021]

[Chemical 7]

And a substituent which the benzene ring has
Is a linear or branched lower chain C1 to C4
Alkyl group, C1-C4 linear or branched lower
Alkoxy group, fluorine atom, chlorine atom, bromine atom, etc.
Halogen atom, nitro group, cyano group, trifluoromethyl
Alkyl group substituted with a fluorine atom, such as a vinyl group, —NR²
R³An amino group represented by -NHCOR^Four Represented by
Acylamino group, -NHCOOR^FiveCar represented by
Bamate group, -NHSO₂ R⁶Sulfonyl represented by
Mid group, -COOR⁷Carboxylic acid ester represented by
Group, -CONR⁸ R⁹ A carbamoyl group represented by
SO₂NR^TenR¹¹Or a sulfamoyl group represented by
SO₃R¹²The sulfonic acid ester group represented by
You can Where R²~ R¹²Are hydrogen atoms,
A substituted or unsubstituted alkyl group, cycloalkyl group,
Allyl group, substituted or unsubstituted vinyl group or substituted
Represents an unsubstituted phenyl group. Hereinafter, the general formula (I)
And typical examples of compounds represented by (II)
However, the compounds used in the present invention do not exceed the gist of the invention.
As long as it is not limited to these specific examples.

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

[Table 3]

[0026]

[Table 4]

[0027]

[Table 5]

[0028]

[Table 6]

[0029]

[Table 7]

[0030]

[Table 8]

[0031]

[Table 9]

[0032]

[Table 10]

[0033]

[Table 11]

In the present invention, the mixing ratio of the dyes (I) and (II) is not particularly limited, but is 2: 8 to 8:
It is common to select from the range of 2. When the coloring material layer is formed on the heat-sensitive transfer sheet of the present invention by using the above-mentioned dye, the method is not particularly limited, and the dye represented by the general formulas (I) and (II) may be used in a medium together with a binder. An ink is prepared by dissolving it in or dissolving it in fine particles,
It can be carried out by applying the ink to a base film and drying it according to a conventional method.

As the binder for preparing the ink, water-soluble resins such as cellulose-based, acrylic acid-based, starch-based, epoxy-based and acrylic resins, methacrylic resins, polystyrene, polycarbonate, polysulfone, polyether sulfone, polyvinyl are used. Examples thereof include resins soluble in organic solvents such as butyral, ethyl cellulose, acetyl cellulose, polyester, AS resin, and phenoxy resin.

As a medium for ink preparation, in addition to water, alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol and isobutyl alcohol, cellosolves such as methyl cellosolve and ethyl cellosolve, and aromas such as toluene, xylene and chlorobenzene. Group, esters such as ethyl acetate and butyl acetate, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, methylene chloride,
Chlorine-based solvents such as chloroform and trichlorethylene,
Ethers such as tetrahydrofuran and dioxane,
Organic solvents such as N, N-dimethylformamide and N-methylpyrrolidone can be mentioned.

In addition to the above components, organic or inorganic non-sublimable fine particles, a dispersant, an antistatic agent, an antifoaming agent, an antioxidant, a viscosity modifier, etc. are added to the above ink as required. be able to. As a base film for applying the ink for producing the transfer sheet, condenser paper, thin paper such as glassine paper, polyester, polycarbonate,
Films of plastics having good heat resistance such as polyamide, polyimide and polyaramid are suitable, and the thickness thereof can be in the range of 3 to 50 μm.

Of the above base films, the polyethylene terephthalate film is particularly advantageous in consideration of mechanical strength, solvent resistance, economy and the like. However, in some cases, the polyethylene terephthalate film does not always have sufficient heat resistance and the running property of the thermal head is insufficient, so that heat resistance that includes a lubricant, heat-resistant particles with high lubricity, etc. on the opposite surface of the color material layer. A thermal head having improved running properties can be used by providing a layer of a functional resin according to a conventional method.

The method of applying the ink to the base film is not particularly limited, but it can be carried out using, for example, a gravure coater, a reverse roll coater, a rod coater, an air doctor coater, etc. The thickness may be applied in a range of 0.1 to 5 μm after drying. The heat-sensitive transfer sheet of the present invention includes
As a heating means, not only a thermal head but also infrared rays, laser light, etc. can be used. Further, it can be used as an electrically conductive dye transfer sheet by using an electrically conductive heat generating film which generates heat by applying electricity to the base film itself.

[0040]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the Examples and Comparative Examples do not limit the present invention as long as the gist thereof is not exceeded. Example 1 a) Preparation of ink

[0041]

Table 12 1) Preparation of ink (A) The dye No. 1-3 3 g The dye No. 2-46 3 g Cellulose acetate 10 g (Product name “L-30”; manufactured by Daicel Chemical Industries, Ltd.) Methyl ethyl ketone 80 g ────────────────────────── ───── Total 96g

An ink was prepared by treating the mixture having the above composition with a paint conditioner for 10 minutes. 2) Preparation of Ink (B) (Magenta Ink) Magenta Ink (B) is the same as Ink (A) except that 6 g of magenta dye having the following structure is used instead of the dye used in Ink (A). Was prepared.

[0043]

[Chemical 8]

3) Preparation of Ink (C) (Cyan Ink) Cyan ink is the same as Ink (A) except that 6 g of cyan dye having the following structure is used instead of the dye used in Ink (A). (C) was prepared.

[0045]

[Chemical 9]

B) Preparation of Transfer Sheet Each of the above inks (A), (B) and (C) was applied onto a polyethylene terephthalate film (6 μm thick) having a back surface subjected to heat-resistant lubrication treatment using a wire bar and dried. (Dry film thickness about 1 μm) Transfer sheet (A),
(B) and (C) were obtained. In addition, the polyethylene terephthalate film is subjected to the heat-resistant lubricity treatment by applying the following formula

[0047]

[Chemical 10]

8 parts by weight of a polycarbonate resin having a repeating structural unit represented by: 1 part by weight of a phosphate ester type interfacial lubricant (product name "Prysurf A-208B"; manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), toluene It was carried out by applying a solution consisting of 91 parts by weight and drying (dry film thickness: about 1 μm).

C) Preparation of image receptor Vinyl chloride-vinyl acetate copolymer resin (product name "VYH
D "; manufactured by Union Carbide Co., Ltd.), amino-modified silicone (product name" KF-393 "; manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 part, methyl ethyl ketone 15 parts, xylene 15 parts. Product name "Yupo FPG1
50 "; made by Oji Yuka Synthetic Paper Co., Ltd. with a wire bar, dried (dry film thickness: about 5 μm), and further 8 in an oven
It was prepared by treating at 0 ° C. for 30 minutes.

D) Transfer recording 1) Yellow color transfer recording The ink coated surface of the transfer sheet (A) is superposed on the image receiving member,
Recording was performed using a thermal head under the following conditions to obtain a medium-colored yellow tone recorded matter. Table 3 shows the color density of the recorded matter and the color measurement results.

[0051]

[Table 13] Recording conditions Recording density for main scanning and sub-scanning: 6 dots / mm Recording power: 0.21 W / dot Energization time: 10 ms For color measurement, use a color difference meter SZ-Σ80 manufactured by Nippon Denshoku Industries Co., Ltd. It was measured. Color density is Macbeth Densitometer TR-
It was measured at 927.

2) Black color transfer recording The transfer sheets (A), (B), and (C) described above were transferred and recorded in this order on the same image receptor under the same recording conditions as in 1) above to record black. A color record was obtained. The results of measuring the color density of this recorded product are shown in Table 3.

E) Light resistance test The light resistance test of the obtained yellow and black color recordings was carried out by a xenon lamp fade meter (Suga Test Instruments Co., Ltd.).
Manufactured by K.K. (black panel temperature: 63 ± 2)
℃), degree of discoloration and fading of recorded material after irradiation for 80 hours {ΔE
(L ^* a ^* b ^* )} is shown in Table-3.

Comparative Example 1 Dye No. which is one component of the mixed dye instead of the mixed dye used in the preparation of the ink (A) of Example 1 was used. 1-3
Ink was prepared, a transfer sheet was prepared, and transfer recording was carried out in the same manner as in Example 1 using 6 g of the above dye only. Table 3 shows the yellow color transfer recording results, the black color transfer recording results, and the light resistance test results.

Comparative Example 2 Dye No. which is one component of the mixed dye instead of the mixed dye used in the preparation of the ink (A) of Example 1 was used. 2-4
Ink preparation, transfer sheet preparation, and transfer recording were carried out in the same manner as in Example 1 using 6 g of the dye of No. 6 only. Table 3 shows the yellow color transfer recording results, the black color transfer results, and the light resistance test results.

[0056]

[Table 14]

Example 2 Using the ink prepared by the following method instead of the ink used in Example 1, the transfer sheet was prepared, the image receptor was prepared and the transfer recording was carried out in the same manner as in Example 1, and the light resistance test was conducted. As a result, it was possible to obtain a recorded product having a medium yellow color tone and a black recorded product having a high color density. The light resistance of the obtained recorded matter and the storage stability of the transfer sheet in the dark were both good.

[0058]

[Table 15] Ink preparation Same pigment as in Example 1 6g AS resin 10g (Product name "Denka AS-S"; manufactured by Denki Kagaku Kogyo Co., Ltd.) Toluene 70g Cyclohexanone 10g ──────────── ──────────────────── Total 96g

[0059]

When the heat-sensitive transfer sheet of the present invention is used,
It is possible to obtain a medium-yellow recorded matter having a high density with low energy, and a black color having a high density can be obtained by mixing with magenta and cyan. Further, the light resistance of the obtained recorded matter is very high. Is very good.

Claims (1)

[Claims] 1. A heat-sensitive transfer sheet having at least a color material layer on a substrate, wherein a binder made of a resin is contained in the color material layer, a disazo dye represented by the following general formula (I), and 1] (In the formula, X ¹ , X ² and X ³ are each a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group, a nitro group, a cyano group, an acylamino group, an alkoxycarbonyl group, an alkylsulfonyl group, a substituted or unsubstituted sulfamoyl group. A group, a trifluoromethyl group or a halogen atom, Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ each represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom or a hydroxy group, or Y ¹ and Y ^2, and Y ⁴ and Y ⁵ may be linked to each other to form an aromatic ring structure.) Pyridone azo dye represented by the following general formula (II): (In the formula, R ¹ represents a hydrogen atom, a substituted or unsubstituted alkyl group, an alkenyl group, a cycloalkyl group or a substituted or unsubstituted phenyl group, Z represents a hydrogen atom or a methyl group, and Represents a benzene ring which may have a nonionic substituent. ) Is contained in the heat-sensitive transfer sheet.