JPH07276828A - Monoazo dye for thermal transfer and thermal transfer sheet - Google Patents

Abstract

PURPOSE:To obtain a thermal transfer sheet imparting a record improved in light fastness and showing a hue of yellow - orange by laminating a colorant layer containing a monoazo dye represented by the specific general formula and a binder on a base material. CONSTITUTION:Aniline represented by the formula I is diazotized according to a usual method and the diazotized reaction product is coupled with phenol represented by the formula II to obtain a monoazo dye represented by the formula III (wherein R1 and R2 are a hydrogen atom, an alkyl group, a halogen atom, a nitro group, a cyano group or the like, R3 and R4 are a hydrogen atom, an alkyl group, an alkoxy group or the like and R5 is a hydrogen atom or an alkyl group). A colorant layer containing the azo dye represented by the formula III and a binder is laminated on a base material to obtain a thermal transfer sheet. As a concrete example of the above mentioned binder, there are a water-soluble resin such as a cellulosic resin and an org. solvent soluble resin such as an acrylic resin, a methacrylic resin, polystyrene or polycarbonate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording monoazo dye used in thermal transfer recording, particularly dye transfer type thermal transfer recording, and a thermal transfer recording sheet using the same.

[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 the dye in the heat-sensitive transfer sheet is transferred to the image-receiving sheet by heating to record. This recording method is applied to full-color image recording in video printers and the like, because the amount of dye transferred can be controlled by the amount of heating energy and gradation can be expressed.

In the dye transfer type thermal transfer recording, the dye used in the transfer sheet and the ink composition for the transfer sheet has a great influence on the transfer recording speed, the image quality of the recorded matter, the storage stability and the like. It is very important, and such a dye needs to satisfy the following conditions. Easily sublimate and / or diffuse heat under the operating conditions of the thermal recording head. Do not thermally 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 is no problem in safety.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a monoazo dye having excellent performance in all of the above-mentioned properties and a heat-sensitive transfer sheet using the same as a dye for dye-transfer type thermal transfer recording. is there. The present invention provides a dye and a heat-sensitive transfer sheet, which are particularly easy to produce a dye, have good light resistance of a recorded matter, and have a yellow to orange color tone.

[0005]

The present invention is directed to a coloring material layer containing a monoazo dye and a binder on a monoazo dye represented by the general formula (I) described in claim 1 and a substrate. A heat-sensitive transfer sheet having the following is a gist thereof. The present invention will be described in detail below.

The monoazo dye represented by the general formula (I) according to the present invention is represented by the following general formula (II)

[0007]

[Chemical 2] (In the formula, R ¹ and R ² have the same meanings as in the general formula (I)), the aniline compound represented by the general formula (III) is diazotized by a conventional method.

[0008]

[Chemical 3] (In the formula, R ³ and R ⁴ have the same meanings as those in the general formula (I)), and a phenol represented by the following general formula (IV) is coupled.

[0009]

[Chemical 4] (In the formula, R ¹ , R ² , R ³ and R ⁴ have the same meanings as in the general formula (I).)

An azo compound represented by the following formula is obtained. This one too
Is the R in the general formula (I). ^FiveIs a hydrogen atom
Is a monoazo dye. In addition, this one
Treatment with an alkylating agent represented by the general formula (V)
The R^FiveA monoazo dye whose
Can be done.

[0011]

Embedded image R ⁵ over Z (V) (wherein, R ⁵ is of the substituents indicated in the formula (I), represent other than hydrogen atoms, Z is a halogen atom)

Alkylation with an alkyl halide is carried out by heating the compound of the general formula (IV) and the compound of the general formula (V) in water or an organic solvent in the presence of a deoxidizing agent. As the organic solvent, N, N-dimethylformamide, N-methylpyrrolidone and the like are particularly advantageous. Examples of the deoxidizing agent include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate and the like. A suitable reaction temperature is usually 50 to 100 ° C.

The dye represented by formula (I) relating to the present invention will be specifically described. In the general formula (I), the substituted or unsubstituted alkyl group for R ¹ , R ² , R ³ and R ⁴ is usually a C _{1 to} C ₆ linear or branched unsubstituted alkyl group. Specifically, a methyl group, an ethyl group, an n-propyl group, an i-propyl group,
Examples thereof include n-butyl group, i-butyl group and n-hexyl group. As the substituted alkyl group, an alkoxy group, an alkoxyalkoxy group, an aryloxy group, an allyloxy group, an aralkyloxy group, an aryl group, a cyano group, a hydroxy group, a halogen atom, an alkoxycarbonyl group, an allyloxycarbonyl group, an acyloxy group, etc. And a C _{1 to} C ₆ linear or branched alkyl group substituted with.

Examples of the substituted or unsubstituted alkoxy group for R ¹ , R ² , R ³ and R ⁴ include C _{1 to} C ₆ linear or branched unsubstituted alkoxy groups, Specific examples include a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, an i-butoxy group and an n-hexyloxy group. The substituted alkoxy group is substituted with an alkoxy group, an aryl group, a cyano group, a hydroxy group, a halogen atom, an alkoxycarbonyl group, an allyloxycarbonyl group, an acyloxy group, an aryloxy group, an allyloxy group, an aralkyloxy group, or the like. Examples thereof include C _{1 to} C ₆ linear or branched alkoxy groups.

Examples of the halogen atom for R ¹ , R ² , R ³ and R ⁴ include fluorine, chlorine, bromine and iodine. Examples of the substituted or unsubstituted alkoxycarbonyl group for R ¹ and R ² include C _{1 to} C ₆ linear or branched alkoxycarbonyl groups, and specific examples include methoxycarbonyl group and ethoxycarbonyl group. Group, n-propoxycarbonyl group, i-propoxycarbonyl group, n-butoxycarbonyl group, i-butoxycarbonyl group, n-hexyloxycarbonyl group and the like. As the substituted alkoxycarbonyl group, an alkoxy group, an aryl group, a cyano group, a hydroxy group,
C substituted with a halogen atom, an acyloxy group, an aryloxy group, an allyloxy group, an aralkyloxy group, etc.
Linear or branched alkoxycarbonyl group having ₁ -C ₆ and the like.

Examples of the substituted or unsubstituted alkylsulfonyl group for R ¹ and R ² include C ₁ -C ₆ linear or branched alkylsulfonyl groups, and more specifically, methylsulfonyl group. , Ethylsulfonyl group, n
-Propylsulfonyl group, i-propylsulfonyl group,
n-butylsulfonyl group, i-butylsulfonyl group, n-
A hexylsulfonyl group and the like can be mentioned. Further, the substituted alkylsulfonyl group is a C ₁ -C ₆ straight chain substituted with an alkoxy group, an aryl group, a cyano group, a hydroxy group, a halogen atom, an acyloxy group, an aryloxy group, an allyloxy group, an aralkyloxy group or the like. Alternatively, a branched alkylsulfonyl group may be mentioned.

Examples of the acylamino group for R ¹ and R ² include C ₁ -C ₄ alkylcarbonylamino groups and benzoylamino groups. The substituted or unsubstituted alkyl group for R ⁵ is usually a C _{1 to} C ₁₂ linear or branched alkyl group, specifically, a methyl group, an ethyl group, an n-propyl group, or an i-propyl group. Base,
n-butyl group, i-butyl group, n-hexyl group, n-octyl group, 2-ethylhexyl group, n-decyl group, n-
Examples include dodecyl group. Further, as the substituted alkyl group, an alkoxy group, an alkoxyalkoxy group, an aryloxy group, an allyloxy group, an aralkyloxy group,
Aryl group, cyano group, hydroxy group, halogen atom,
Alkoxycarbonyl group, allyloxycarbonyl group,
Examples thereof include a C _{1 to} C ₈ linear or branched alkyl group substituted with an acyloxy group and the like.

In the above, specific examples of the alkyl group substituted with an alkoxy group include methoxymethyl group and 2-
Methoxyethyl group, 2-ethoxyethyl group, 2-n-propoxyethyl group, 2-n-butoxyethyl group, 2-i
-Butoxyethyl group, 1-methyl-2-methoxyethyl group, 1-methyl-2-ethoxyethyl group, 3-methoxybutyl group, 3-ethoxybutyl group, 1-ethyl-2-methoxyethyl group and the like. .

Specific examples of the alkyl group substituted with an aralkyloxy group include a benzyloxymethyl group,
2-benzyloxyethyl group, 1-methyl-2-benzyloxyethyl group, 1-ethyl-2-benzyloxyethyl group and the like can be mentioned. The alkyl group substituted with an allyloxy group includes an allyloxymethyl group, 2
-Allyloxyethyl group, 1-methyl-2-allyloxyethyl group, 1-ethyl-2-allyloxyethyl group and the like.

Examples of the alkyl group substituted with an aryloxy group include a phenoxymethyl group and a 2-phenoxyethyl group. The alkyl group substituted with an alkoxyalkoxy group includes a methoxymethoxymethyl group, a (2′-methoxyethoxy) methyl group, a 2- (2′-methoxyethoxy) ethyl group, and a 2- (2′-ethoxyethoxy) group. Examples thereof include an ethyl group and a 4- (2′-methoxyethoxy) butyl group.

Examples of the alkyl group substituted with a cyano group include a cyanomethyl group and a 2-cyanoethyl group. Examples of the alkyl group substituted with a hydroxy group include a hydroxymethyl group, a 2-hydroxyethyl group, a 3-hydroxypropyl group and a 1-methyl-2-hydroxyethyl group.

As the alkyl group substituted with a halogen atom, chloromethyl group, 2-chloroethyl group, 2
-Bromoethyl group and the like. In addition, examples of the alkyl group substituted with an alkoxycarbonyl group or an allyloxycarbonyl group include a methoxycarbonylmethyl group, a 2-methoxycarbonylethyl group, a 2-ethoxycarbonylethyl group, an ethoxycarbonylmethyl group, an allyloxycarbonylmethyl group, 2 Examples include -allyloxycarbonylethyl group and n-butoxycarbonylmethyl group.

Examples of the alkyl group substituted with an acyloxy group include acetoxymethyl group, 2-acetoxyethyl group, benzoyloxymethyl group, 2-benzoyloxyethyl group, 3-acetoxypropyl group and the like. Moreover, examples of the alkyl group substituted with an aryl group include a benzyl group, a p-chlorobenzyl group, and a 2-phenylethyl group.

In the above, the alkoxy group substituted with an alkoxy group includes a methoxymethoxy group, a 2-methoxyethoxy group, a 2-ethoxyethoxy group, a 2-n-propoxyethoxytyl group, a 2-n-butoxyethoxy group, Examples thereof include a 2-i-butoxyethoxy group, a 1-methyl-2-methoxyethoxy group, a 1-methyl-2-ethoxyethoxy group, a 3-methoxybutoxy group and a 3-ethoxybutoxy group.

Examples of the alkoxy group substituted with an aralkyloxy group include a benzyloxymethoxy group, a 2-benzyloxyethoxy group, a 1-methyl-2-benzyloxyethoxy group, a 1-ethyl-2-benzyloxyethoxy group and the like. . Examples of the alkoxy group substituted with an allyloxy group include an allyloxymethoxy group, a 2-allyloxyethoxy group and a 1-methyl-2-allyloxyethoxy group.

Examples of the alkoxy group substituted with an aryloxy group include a phenoxymethoxy group and a 2-phenoxyethoxy group. In addition, examples of the alkoxy group substituted with a cyano group include a cyanomethoxy group and 2
-Cyanoethoxy group and the like. Examples of the alkoxy group substituted with a hydroxy group include a hydroxymethoxy group, a 2-hydroxyethoxy group, a 3-hydroxypropoxy group, a 1-methyl-2-hydroxyethoxy group and the like.

Examples of the alkoxy group substituted with a halogen atom include a chloromethoxy group, a 2-chloroethoxy group and a 2-bromoethoxy group. Also,
Examples of the alkoxy group substituted with an alkoxycarbonyl group or an allyloxycarbonyl group include a methoxycarbonylmethoxy group, a 2-methoxycarbonylethoxy group, a 2-ethoxycarbonylethoxy group, an ethoxycarbonylmethoxy group, an allyloxycarbonylmethoxy group, and an allyloxycarbonyl group. Examples thereof include ethoxy group and n-butoxycarbonylmethoxy group.

Examples of the alkoxy group substituted with an acyloxy group include acetoxymethoxy group, 2-acetoxyethoxy group, benzoyloxymethoxy group, 2-benzoyloxyethoxy group and 3-acetoxypropoxy group. In addition, examples of the alkoxy group substituted with an aryl group include a benzyloxy group, a p-chlorobenzyloxy group, and a 2-phenylethoxy group.

In the above, as the alkoxycarbonyl group substituted with an alkoxy group, a methoxymethoxycarbonyl group, a 2-methoxyethoxycarbonyl group, a 2-ethoxyethoxycarbonyl group, a 2-n-propoxyethoxycarbonyl group, a 2-n- Examples thereof include a butoxyethoxycarbonyl group, a 2-i-butoxyethoxycarbonyl group, a 1-methyl-2-methoxyethoxycarbonyl group, a 1-methyl-2-ethoxyethoxycarbonyl group, a 3-methoxybutoxycarbonyl group and a 3-ethoxybutoxycarbonyl group.

The alkoxycarbonyl group substituted with an aralkyloxy group is a benzyloxymethoxycarbonyl group, a 2-benzyloxyethoxycarbonyl group, a 1-methyl-2-benzyloxyethoxycarbonyl group, a 1-ethyl-2-benzyloxyethoxycarbonyl group. Groups and the like. Examples of the alkoxycarbonyl group substituted with an allyloxy group include an allyloxymethoxycarbonyl group, a 2-allyloxyethoxycarbonyl group and a 1-methyl-2-allyloxyethoxycarbonyl group.

Examples of the alkoxycarbonyl group substituted with an aryloxy group include a phenoxymethoxycarbonyl group and a 2-phenoxyethoxycarbonyl group. In addition, examples of the alkoxycarbonyl group substituted with a cyano group include a cyanomethoxycarbonyl group and 2
Examples of the alkoxycarbonyl group in which a -cyanoethoxycarbonyl group or the like is substituted with a hydroxy group include a hydroxymethoxycarbonyl group, a 2-hydroxyethoxycarbonyl group, a 3-hydroxy-n-propoxycarbonyl group, a 1-methyl-2-hydroxyethoxycarbonyl group and the like. Is mentioned. Examples of the alkoxycarbonyl group substituted with a halogen atom include a chloromethoxycarbonyl group, a 2-chloroethoxycarbonyl group and a 2-bromoethoxycarbonyl group.

The alkoxycarbonyl group substituted with an acyloxy group includes an acetoxymethoxycarbonyl group, a 2-acetoxyethoxycarbonyl group, a benzoyloxymethoxycarbonyl group, a 2-benzoyloxyethoxycarbonyl group and a 3-acetoxy-n-propoxycarbonyl group. Groups and the like. In addition, examples of the alkoxycarbonyl group substituted with an aryl group include a benzyloxycarbonyl group, a p-chlorobenzyloxycarbonyl group, and a 2-phenylethoxycarbonyl group.

In the above, examples of the alkylsulfonyl group substituted with an alkoxy group include a methoxymethylsulfonyl group, a 2-methoxyethylsulfonyl group, a 2-ethoxyethylsulfonyl group, a 2-n-propoxyethylsulfonyl group and a 2-n- Examples thereof include a butoxyethylsulfonyl group, a 2-i-butoxyethylsulfonyl group, a 1-methyl-2-methoxyethylsulfonyl group, a 1-methyl-2-ethoxyethylsulfonyl group, a 3-methoxybutylsulfonyl group and a 3-ethoxybutylsulfonyl group.

The alkylsulfonyl group substituted with an aralkyloxy group includes a benzyloxymethylsulfonyl group, a 2-benzyloxyethylsulfonyl group,
1-methyl-2-benzyloxyethylsulfonyl group,
Examples thereof include a 1-ethyl-2-benzyloxyethylsulfonyl group. Examples of the alkylsulfonyl group substituted with an allyloxy group include an allyloxymethylsulfonyl group, a 2-allyloxyethylsulfonyl group and a 1-methyl-2-allyloxyethylsulfonyl group.

Examples of the alkylsulfonyl group substituted with an aryloxy group include a phenoxymethylsulfonyl group and 2-phenoxyethylsulfonyl group. Further, the alkylsulfonyl group substituted with a cyano group includes cyanomethylsulfonyl group. Examples of the alkylsulfonyl group in which a 2-cyanoethylsulfonyl group or the like is substituted with a hydroxy group include a hydroxymethylsulfonyl group, a 2-hydroxyethylsulfonyl group, a 3-hydroxy-n-propylsulfonyl group, and a 1-methyl-2-hydroxyethylsulfonyl group. Groups and the like.

As the alkylsulfonyl group substituted with a halogen atom, chloromethylsulfonyl group, 2
-Chloroethylsulfonyl group, 2-bromoethylsulfonyl group, and the like. Examples of the alkylsulfonyl group substituted with an acyloxy group include an acetoxymethylsulfonyl group, a 2-acetoxyethylsulfonyl group, a benzoyloxymethylsulfonyl group, a 2-benzoyloxyethylsulfonyl group and a 3-acetoxypropylsulfonyl group. .

Examples of the alkylsulfonyl group substituted with an aryl group include a benzylsulfonyl group, a p-chlorobenzylsulfonyl group and a 2-phenylethylsulfonyl group. In the present invention, it is preferable that the group of OR ⁵ in the general formula (I) is substituted at the ortho position or the para position with respect to the azo group.

Table 1 shows specific examples of the dye represented by the general formula (I). The numerals described in the left of each group are listed in the R ¹ to R ⁴ and OR ⁵ each represent a respective substitution position of R ¹ to R ⁴ and OR ^5.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

[Table 3]

[0042]

[Table 4]

[0043]

[Table 5]

In the heat-sensitive transfer sheet of the present invention, the coloring material layer contains one or more kinds of the dyes represented by the general formula (I). Further, in addition to the dye represented by the general formula (I), a dye having another structure may be used in combination. When a coloring material layer is formed using the above dye on the heat-sensitive transfer sheet of the present invention,
The method is not particularly limited, and it is usually carried out by dissolving the pigment in a medium together with a binder or dispersing it in fine particles to prepare an ink, coating the ink on a base film as a substrate, and drying. can do.

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. Resins soluble in organic solvents such as butyral, ethyl cellulose, acetyl cellulose, polyester, AS resin, and phenoxy resin can be given.

As a medium for preparing the ink, 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 adjusting agent, etc. are added to the above ink. I can do things. As a base film for applying ink for making a transfer sheet, condenser paper, thin paper such as glassine paper, polyester, polycarbonate, polyamide, polyimide, a film of good heat resistance plastic such as polyaramid is suitable. 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 heat resistance of polyethylene terephthalate film is not always sufficient, and the running performance of the thermal head is insufficient, so that heat resistance including lubricant, heat-stable fine particles, etc. on the opposite surface of the color material layer By providing a resin layer, a thermal head having improved running properties can be used.

As a method of applying the ink to the base film, a gravure coater, a reverse roll coater,
It can be carried out using a rod coater, an air doctor coater, etc., and the thickness of the ink coating layer is 0.1 after drying.
It may be applied in a range of up to 5 μm. Further, the heat-sensitive transfer sheet of the present invention can utilize not only a thermal head but also infrared rays, laser light, etc. as a heating means. Further, it can be used as an electrically conductive dye transfer sheet by using an electrically conductive heat-generating film that generates heat by applying electricity to the base film itself. [Examples] The present invention will be specifically described with reference to the following examples, but the examples do not limit the present invention.

Example 1 a) No. 1 in Table 1 Synthesis of Dye of 23. 12.4 g (0.1 mol) of p-nitroaniline was charged into 300 ml of an aqueous hydrochloric acid solution, and an aqueous solution of 6.6 g (0.1 mol) of sodium nitrite was added dropwise at 0 to 5 ° C. Diazotization was carried out by stirring at temperature for 2 hours. p-cresol 1
0.8 g (0.1 mol) was dissolved in a mixed solution of 85 ml of water, 4.3 g of sodium hydroxide and 8.6 g of sodium acetate, and the diazo solution obtained above was added thereto with a sodium hydroxide aqueous solution to obtain a pH of 8.5. The mixture was added dropwise at 0 to 5 ° C while adjusting to 9.5 and stirred at the same temperature for 2 hours. After the reaction is completed, water 2500
ml, and the precipitated crystals were filtered, washed with water and dried, and the obtained crystals were purified by suspension washing with 300 ml of methyl alcohol to obtain 21.8 g of yellow crystals.

In the mass spectrum of this product, the parent ion peak was 257. It was in agreement with the molecular weight of the structural formula of 23. The maximum absorption wavelength in acetone is 41
7 nm and the melting point was 183.6 ° C. b) Preparation of ink

[0052]

[Table 6] No. 1 in Table 1 Dye of 23 6 parts by weight Cellulose acetate 10 parts by weight (Product name: L-30; product of Daicel Chemical Industries, Ltd.) Methyl ethyl ketone 80 parts by weight ───────────────────── ────────────── Total 96 parts by weight A mixture of the above composition was treated with a paint conditioner for 10 minutes to prepare an ink.

C) Preparation of heat-sensitive transfer sheet Polyethylene terephthalate film (6 μm) whose back surface is heat-resistant and slip-treated with a wire bar using the above ink
(Thickness) and then dried (dry film thickness: about 1 μm) to obtain a heat-sensitive transfer sheet. In addition, the polyethylene terephthalate film is subjected to the heat-resistant lubricity treatment by applying the following formula

[0054]

[Chemical 6]

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

D) Preparation of image receptor Vinyl chloride-vinyl acetate copolymer resin (Product name: VYH
D: union carbide product) 10 parts by weight, amino-modified silicone (product name: KF-393; product of Shin-Etsu Chemical Co., Ltd.) 0.5 parts by weight, methyl ethyl ketone 15 parts by weight, xylene 15 parts by weight mixed solution with synthetic paper ( Product name: YUPO FPG150; product of Oji Yuka Co., Ltd.) was coated with a wire bar, dried (dry film thickness: about 5 μm), and further treated in an oven at 80 ° C. for 30 minutes to prepare. e) Transfer recording The ink-coated surface of the above-mentioned thermal transfer sheet is superposed on the image receiver,
Recording was performed using a thermal head under the following conditions to obtain a recorded matter having a color tone shown in Table 2 and having excellent color density.

[0057]

[Table 7] Recording conditions Recording density in main scanning and sub-scanning: 6 dots / mm Recording power: 0.21 W / dot Energization time: 10 ms Color density was measured using Macbeth Densitometer TR-927 did.

F) Light resistance test A light resistance test of the obtained recorded matter (having a recording density of about 1.0) was carried out using a xenon lamp fade meter (manufactured by Suga Test Instruments Co., Ltd.) (black panel temperature: 63
Degree of discoloration and fading of recorded matter after exposure for ± 2 ° C, 80 hours (△
E (L * a * b *)) is shown in Table 2 below.

Example 2 a) No. 1 in Table 1 Synthesis of 52 dyes 19.8 g (0.1 mol) of p-phenylazophenol
Was charged into 200 ml of N-methylpyrrolidone, 16.0 g of sodium carbonate and 19.0 g of ethyl iodide were added,
It stirred at 60-70 degreeC for 6 hours. After the reaction, water 130
0 g was added and the precipitated crystals were filtered, washed with water and dried. The obtained crystals were purified by suspension washing with 200 ml of methyl alcohol to obtain 18.9 g of yellow crystals.

In the mass spectrum of this product, the parent ion peak was 226. It was in agreement with the molecular weight of the structural formula of 52. The maximum absorption wavelength in acetone is 43
4 nm and melting point was 69.7 ° C. b) Using the dye obtained by the above synthesis instead of the dye used in Example 1, and by the same method as in Example 1, ink preparation, transfer sheet preparation, image receptor preparation and transfer recording, light resistance. A sex test was conducted and the results shown in Table 2 below were obtained.

Examples 3 to 13 In Example 1, No. 1 in Table 1 above was used. The dyes shown in Table 2 below were used instead of the dyes of No. 23, and the dye synthesis, ink preparation, transfer sheet preparation, image receptor preparation and transfer recording, and light resistance test were conducted in the same manner as in Example 1. The results shown in Table 2 below were obtained.

[0062]

[Table 8]

Example 14 Using the ink prepared by the following method instead of the ink used in Example 1, the same method as in Example 1 was carried out to prepare a transfer sheet, an image receptor, transfer recording and light resistance. As a result of the test, it was possible to obtain a record of clear yellow and uniform color density. The light resistance of the obtained recording and the storage stability of the transfer sheet in the dark were both good.

[0064]

Table 9 Ink Preparation No. 1 in Table 1 Dye of 23 6 parts by weight AS resin (product name: Denka AS-S; product of Denki Kagaku Kogyo Co., Ltd.) 10 parts by weight Toluene 70 parts by weight Cyclohexanone 10 parts by weight ─────────────── ───────────────────── Total 96 parts by weight

[0065]

When the heat-sensitive transfer sheet of the present invention is used,
It is possible to obtain a clear yellow recorded matter with low energy and high density, and the recorded matter obtained by this heat-sensitive transfer sheet has particularly good light resistance.

Claims (2)

[Claims] 1. The following general formula (I): (In the formula, R ¹ and R ² are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a halogen atom, a nitro group, a cyano group, a substituted or unsubstituted alkoxycarbonyl group, Represents a substituted or unsubstituted alkylsulfonyl group or an acylamino group, R ³ and R ⁴ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a halogen atom or a hydroxy group, R ⁵ represents a hydrogen atom or a substituted or unsubstituted alkyl group.) A monoazo dye for heat-sensitive transfer. 2. A heat-sensitive transfer sheet having a color material layer containing a monoazo dye represented by the general formula (I) according to claim 1 and a binder on a substrate.