JP3163799B2 - Pyrrole azo dye and thermal transfer sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel pyrrole azo dye and a thermal transfer recording sheet using the dye, and more particularly to a thermal transfer recording sheet used for dye transfer type thermal transfer recording.

[0002]

2. Description of the Related Art In a dye transfer type thermal transfer recording, a thermal 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 on each other. Is a recording method in which recording is performed by heating the heat-sensitive transfer sheet to transfer the dye in the heat-sensitive transfer sheet to the image receiving sheet. This recording method is applied to full-color image recording such as a video printer, since the transfer amount of the dye is controlled by the magnitude of the heating energy to enable gradation expression.

In the dye transfer type thermal transfer recording, the dye used in the ink composition of the transfer sheet is very important because it greatly affects the speed of the transfer recording, the image quality of the recorded matter, the storage stability, and the like. It is necessary to satisfy the following conditions. Easily sublimates and / or thermally diffuses under the operating conditions of the thermal recording head. Does not thermally decompose under the operating conditions of the thermal recording head. Large molecular extinction coefficient. Stable against heat, light, moisture, chemicals, etc. Easy to synthesize. Excellent ink suitability. No health and safety issues.

[0004]

SUMMARY OF THE INVENTION The present inventors have studied pyrroleazo dyes in order to find a dye having excellent performance as a thermal transfer dye.

[0005]

Means for Solving the Problems The present inventors have found that the pyrroleazo dye represented by the formula (I) described in claim 1 is excellent as a dye for thermal transfer. Hereinafter, the present invention will be described in detail. The pyrroleazo dye represented by the general formula (I) according to the present invention is obtained by diazotizing 2-cyano-3-amino-4-acetyl-5-methylpyrrole according to a usual method,

[0006]

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(Wherein X, Y, R ² and R ³ have the same meanings as in the above formula (I)), and are coupled to an aniline represented by the following formula (III):

[0008]

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(Wherein X, Y, R ² and R ³ have the same meanings as in the above formula (I)), and the azo compound is optionally treated with an alkylating agent. Can be obtained. As the alkylating agent, the following general formula (IV) R ¹ -Z (IV) (wherein, R ¹ has the same meaning as in the general formula (I);
Z represents a halogen atom). Alkylation using an alkyl halide is carried out in water or an organic solvent in the presence of a deoxidizing agent (III)
This is carried out by heating the compound of the formula and the compound of the formula (IV). 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. The reaction temperature is usually 50 to
100 ° C. is suitable.

The dye represented by formula (I) according to the present invention will be specifically described. In formula (I), examples of the alkyl group represented by R ¹ , R ² , and R ³ include a C ₁ -C ₁₂ linear or branched alkyl group. Examples of the substituted alkyl group represented by R ¹ , R ² and R ³ include 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, a furyl group, tetrahydrofuryl group, an alkoxycarbonyl group, an allyloxycarbonyl group, include straight chain or branched alkyl group of C ₁ -C ₈ substituted with and acyloxy groups. Specific examples of such a substituted alkyl group include the following.

Examples of the alkyl group substituted by an alkoxy group include a 2-methoxyethyl group, a 2-ethoxyethyl group,
2- (n) propoxyethyl group, 2- (iso) propoxyethyl group, 2- (n) butoxyethyl group, 2- (i
so) 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-ethoxy butyl group, 1-ethyl-2-methoxyethyl group, and a 1-ethyl-2-ethoxyethyl group, particularly 2-alkoxyethyl group C ₃ -C ₈ preferred.

The alkyl group substituted with an aralkyloxy group includes 2-benzyloxyethyl, 1-methyl-2-benzyloxyethyl, 1-ethyl-2-benzyloxyethyl, and 2- (2'- A phenylethyloxy) ethyl 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 and a 1-methyl-2-
A phenoxyethyl group, a 1-ethyl-2-phenoxyethyl group, and the like. 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) octyloxyethoxy} 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) particularly but a butyl group, a C ₅ -C ₁₀ 2-
(2'-Alkoxyethoxy) ethyl groups are preferred.

Examples of the alkyl group substituted with a cyano group include a 2-cyanoethyl group and a cyanomethyl group. Examples of the alkyl group substituted with a hydroxy group include a 2-hydroxyethyl group, a 3-hydroxy (n) propyl group and a 4-hydroxy (n) propyl group. Examples thereof include a hydroxy (n) butyl group, a 1-methyl-2-hydroxyethyl group, a 1-ethyl-2-hydroxyethyl group, and the like. Examples of the alkyl group substituted with a halogen atom include 2-chloroethyl group, 2-bromoethyl group, 2,2,2
Examples of the alkyl group in which a trifluoroethyl group or the like is substituted with a furyl group include a furfuryl group. As an alkyl group substituted with a tetrahydrofuryl group, a tetrahydrofurfuryl group is used, and as an alkyl group substituted with an aryl group, a benzyl group, a p-chlorobenzyl group,
A 2-phenylethyl group and the like.

Examples of the alkyl group substituted by an alkoxycarbonyl group or an allyloxycarbonyl group include a 2-methoxycarbonylethyl group, a 2-ethoxycarbonylethyl group, a 2- (iso) butoxycarbonylethyl group,
-(N) hexyloxycarbonylethyl group, 1-methyl-2-methoxycarbonylethyl group, 1-methyl-2
-(N) butoxycarbonylethyl group, 2-allyloxycarbonylethyl group, 1-methyl-2-allyloxycarbonylethyl group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, (iso) butoxycarbonylmethyl group, (n) Examples include a hexyloxycarbonylmethyl group and a 2-ethylhexyloxycarbonylmethyl group.

Examples of the alkyl group substituted by an acyloxy group include 2-acetoxyethyl, 2-propionyloxyethyl, 2-benzoyloxyethyl, 3-acetoxy (n) propyl, and 4-acetoxy (n) butyl. A 1-methyl-2-acetoxyethyl group, a 1-ethyl-2-acetoxyethyl group, and the like. R ¹ ,
Examples of the cycloalkyl group represented by R ² and R ³ include a cyclopentyl group and a cyclohexyl group.

The acylamino group represented by X includes C
₁ -C ₄ alkylcarbonylamino group, a benzoylamino group. Among the substituents of the general formula (I), among the substituents represented by R ¹ , R ² , and R ³ , particularly preferred are C ₁ -C ₈ alkyl groups or alkoxyalkyl groups. Hydrogen atom,
A methyl group or an acetylamino group, particularly preferred as Y is a hydrogen atom, a methoxy group or an ethoxy group.

Some specific examples of the dye represented by formula (I) are shown in Table 1.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

[Table 3]

[0022]

[Table 4]

[0023]

[Table 5]

The formation of the coloring material layer of the heat-sensitive transfer sheet using the above-mentioned coloring matter according to the present invention can be carried out by a conventional method. Usually, a colorant layer can be formed by preparing an ink by dissolving or dispersing a dye in a medium together with a binder in the form of fine particles, applying the ink to a base film, and drying.

Examples of the binder for preparing the ink include water-soluble resins such as cellulose, acrylic acid, starch and epoxy, acrylic resin, methacrylic resin, polystyrene, polycarbonate, polysulfone, polyethersulfone, and the like. Resins soluble in organic solvents such as polyvinyl butyral, ethyl cellulose, acetyl cellulose, polyester, AS resin, and phenoxy resin can be used.

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, toluene, xylene and chlorobenzene. Aromatics, ethyl acetate, esters such as butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, ketones such as cyclohexanone, methylene chloride,
Chlorine solvents such as chloroform and trichloroethylene,
Ethers such as tetrahydrofuran and dioxane,
Nitrogen-containing organic solvents such as N, N-dimethylformamide and N-methylpyrrolidone can be used.

[0027] In addition to the above components, organic and inorganic non-sublimable fine particles, a dispersant, an antistatic agent, an antifoaming agent, an antioxidant, a viscosity modifier and the like are added to the above-mentioned inks as required. You can do it. As a base film for applying ink for transfer sheet production, condenser paper, tissue paper such as glassine paper, polyester, polycarbonate,
A plastic film having good heat resistance such as polyamide, polyimide, and polyaramid is suitable. The thickness of the base film is usually 3 to 50 μm.

Among the above base films, a 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 performance of the thermal head may be insufficient. In such a case, it is preferable to use a layer in which the running property of the thermal head is improved by providing a layer of a heat-resistant resin containing a lubricant, heat-resistant particles having high lubricity on the opposite surface of the color material layer.

To apply the ink to the base film,
It can be carried out using a conventional coating device such as a gravure coater, a reverse roll coater, a rod coater, and an air doctor coater. The ink may be applied so that the thickness of the coating layer is in the range of 0.1 to 5 μm after drying. The heat-sensitive transfer sheet of the present invention can use not only a thermal head but also an infrared ray or a laser beam as a heating means. In addition, a current-carrying film that generates heat by passing electricity through the base film itself can be used as a current-carrying dye transfer sheet.

[0030]

The present invention will be described more specifically with reference to the following examples. Example 1 a) Synthesis of Dye 16.3 g (0.1 mol) of 2-cyano-3-amino-4-acetyl-5-methylpyrrole was charged in 100 ml of acetic acid, and 30 g of 95% sulfuric acid was added at 0 to 5 ° C. Nitrosyl sulfuric acid prepared from 7.2 g (0.105 mol) of sodium nitrite was added dropwise, and the mixture was stirred at the same temperature for 1 hour to perform diazotization. Next, 16.3 g of N, N-diethyl-m-toluidine
(0.1 mol) in 100 ml of water and 100 ml of methanol
In which the diazo solution obtained above was added in an amount of 0 to 5
C. and the mixture was stirred at the same temperature for 2 hours while adjusting the pH to 4 to 5 with sodium acetate to carry out a coupling reaction. After completion of the reaction, the precipitated crystals were filtered, washed with water, and dried to obtain 11.5 g of orange crystals.

The crystals were charged in 100 ml of N, N-dimethylformamide, and 3.5 g of potassium carbonate (0.025
5 mol) and 9.4 g (0.05) of isobutyl iodide
1 mol) and stirred at 70-80 ° C for 3 hours. After cooling to room temperature, 100 ml of water was added, and the precipitated crystals were filtered, washed with water and dried. This was dissolved in chloroform and purified through a silica gel column to obtain 3.7 g of orange crystals.

The mass spectrum of this product has a parent ion peak of 393, and Table 1 This was consistent with the molecular weight of the structural formula 2. The maximum absorption wavelength in acetone was 484 nm. Melting point was 151-152 ° C.

[0033]

[Table 6] b) Preparation of ink 6 parts by weight of pigment 6 parts by weight of cellulose acetate (product name: L-30; product of Daicel Chemical Industries, Ltd.) 80 parts by weight of methyl ethyl ketone ９６Total 96 parts by weight The 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 A polyethylene terephthalate film (6 μm
Thick) and dried (dry film thickness: about 1 μm) to obtain a heat-sensitive transfer sheet. The heat-resistant lubrication treatment of the polyethylene terephthalate film is performed by adding the following formula to the polyethylene terephthalate film.

[0035]

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8 parts by weight of a polycarbonate resin having a repeating structural unit represented by the following formula, 1 part by weight of a phosphate ester surfactant (product name: Plysurf A-208B; a product of Daiichi Kogyo Seiyaku Co., Ltd.), and 91 parts by weight of toluene Was applied and dried (dry film thickness: about 1 μm).

D) Preparation of Image Receiver 10 parts by weight of polyvinyl chloride resin (product name: VYHD; Union Carbide product), amino-modified silicone (product name: KF)
-393; Shin-Etsu Chemical Co., Ltd. product) 0.5 parts by weight,
A liquid consisting of 15 parts by weight of methyl ethyl ketone and 15 parts by weight of xylene is applied to synthetic paper (product name: YUPO FPG150; product of Oji Yuka Co., Ltd.) using a wire bar, dried (dry film thickness: about 5 μm), and further dried in an oven. It was produced by treating at 30 ° C. for 30 minutes.

E) Transfer recording The ink-coated surface of the above-mentioned heat-sensitive transfer sheet is superimposed on an image receiving body.
Recording was carried out using a thermal head under the following conditions, and a recorded matter having the color tone shown in Table 2 and having excellent color density was obtained. Recording conditions Main scanning and sub-scanning recording density: 6 dots / mm Recording power: 0.21 W / dot Energizing time: 10 milliseconds f) Light fastness test The obtained printed matter (with a color density of about 1.0) A light fastness test was performed using a xenon lamp fade meter (manufactured by Suga Test Instruments Co., Ltd.) (black panel temperature: 63 ±
2 ° C.) for 40 hours, but the discoloration was small.

[0039]

[Table 7]

Examples 2 to 9 The dyes shown in Table 2 were used in place of the dyes used in Example 1 in the same manner as in Example 1 to synthesize dyes, prepare inks, prepare transfer sheets, and prepare image receiving members. Production and transfer recording,
A light fastness test was performed to obtain recorded matters having the color tone shown in Table 2 and having excellent color density.

[0041]

When the dye of the present invention is used in a heat-sensitive transfer sheet, it is possible to obtain a low-energy, high-density recorded matter having a clear color tone, and the obtained recorded matter has good light fastness.

Continuation of front page (56) References JP-A-4-122777 (JP, A) JP-A-3-197185 (JP, A) JP-A-62-220557 (JP, A) JP-A-63-15857 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C09B 29/036 C09B 29/09 CA (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. A compound represented by the following general formula (I) (In the formula, X represents a hydrogen atom, a methyl group or an acylamino group, Y represents a hydrogen atom or a lower alkoxy group, R ¹ , R ² and R ³ may be different from each other, and may be a hydrogen atom, substituted or unsubstituted. A substituted alkyl, cycloalkyl or allyl group). 2. A heat-sensitive transfer sheet comprising a coloring material layer containing a pyrroleazo dye represented by the general formula (I) according to claim 1.