JP5353038B2 - Pyrazolotriazole azomethine derivative and dye for thermal transfer recording using the same - Google Patents

Description

  The present invention relates to a thermal transfer recording dye, and more particularly to a novel pyrazolotriazole azomethine derivative which is inexpensive and excellent in light resistance and a method for producing the same.

  The heat-sensitive sublimation transfer method uses a thermal transfer film that carries a dye layer in which a sublimable dye is dissolved or dispersed in a binder resin. The thermal transfer film is layered on the image-receiving film and is transferred to a heating device such as a thermal head. By applying energy according to the above, the sublimation dye contained in the dye layer on the thermal transfer film is transferred to the image receiving film to form an image.

  This heat-sensitive sublimation transfer method can control the amount of dye transfer in dot units according to the amount of energy applied to the thermal transfer film, so that it is excellent in forming a gradation image and has advantages such as easy formation of characters, symbols, etc. have.

  The image obtained by such a thermal transfer method can form a high-quality image similar to a silver salt photograph, and accordingly, there is an extremely high demand for prevention of image quality degradation due to factors such as light, heat, and humidity of the image. Development of various sublimation dyes for improving image storage stability has been made.

  For example, JP-A-6-106868 (Patent Document 1) discloses 1H-pyrazolo [5,1-C] as a pyrazolotriazole-based azomethine dye, which is a magenta dye, having excellent color reproducibility and light resistance. An azomethine dye having a [1,2,4] triazole ring as a coupler has been proposed.

  However, since the 1H-pyrazolo [5,1-C] [1,2,4] triazole ring coupler compound that is the raw material of the above dye is expensive, the azomethine dye using the coupler has a cost problem. It was.

On the other hand, a pyrazolotriazole azomethine dye having a structure in which a 1H-pyrazolo [5,1-b] [1,2,4] triazole ring and diethylaniline are bonded via an azomethine bond is known (Patent Document 2). : Japanese Patent No. 2069761). Although this dye uses a 1H-pyrazolo [5,1-b] [1,2,4] triazole ring compound as a raw material coupler, it is relatively inexpensive, but sometimes has insufficient light resistance.
JP-A-6-106868 Japanese Patent No. 2069761

  The present inventors use 1H-pyrazolo [5,1-b] [1,2,4] triazole ring couplers, which are available relatively inexpensively, and use compounds having a specific structure containing a heterocyclic group in the azomethine linking group. As a result, it has been found that a pyrazolotriazole-based azomethine dye that is inexpensive and excellent in light resistance can be realized. The present invention is based on such knowledge.

  Accordingly, an object of the present invention is to provide a novel pyrazolotriazole-based azomethine derivative that is inexpensive and excellent in light resistance.

  Another object of the present invention is to provide a dye for thermal transfer recording using the above compound.

  Another object of the present invention is to provide a thermal transfer recording material using the above thermal transfer recording dye.

（式中、
Ｒ_１は、アルキル基またはアリール基を表し、
Ｒ_２は、水素原子、アルキル基、アリール基、ヘテロ環基、アルコキシ基、カルボニル基、アルコキシカルボニル基、シアノ基、カルバモイル基、アリールアミン基、アリールニトロ基、またはアリールアミド基を表し、
Ｒ_３は、水素原子またはアルキル基を表し、
Ｙ_１〜Ｙ_４は、それぞれ独立して、窒素原子、またはＣＨもしくはＲ_３を置換した炭素原子を表すが、Ｙ_１〜Ｙ_４の少なくとも１つは窒素原子である。）。 The pyrazolotriazole-based azomethine derivative according to the present invention is represented by the following formula I.

(Where
R ₁ represents an alkyl group or an aryl group,
R ₂ represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, a carbonyl group, an alkoxycarbonyl group, a cyano group, a carbamoyl group, an arylamine group, an arylnitro group, or an arylamide group,
R ₃ represents a hydrogen atom or an alkyl group,
Y _{1 to} Y ₄ each independently represent a nitrogen atom or a carbon atom substituted with CH or R _3, and at least one of Y _{1 to} Y ₄ is a nitrogen atom. ).

In the present invention, R _{2 in the} formula I is preferably an alkyl group, an arylnitro group, or an arylamide group.

In the present invention, R _{1 in the} formula I is preferably an alkyl group having a branched chain.

Furthermore, in the present invention, it is preferable that R _{2 of the} formula I is a methyl group.

（式中、Ｒ_１〜Ｒ_３およびＹ_１〜Ｙ_４は、上記の定義と同じである。） In another embodiment of the present invention, there is provided a method for producing the above pyrazolotriazole-based azomethine derivative, wherein a compound represented by the following formula II and a compound represented by the following formula III are made of sodium persulfate Reacting in the presence.

(In the formula, R _{1 to} R ₃ and Y _{1 to} Y ₄ are the same as defined above.)

  Furthermore, in another embodiment of the present invention, there is also provided a thermal transfer recording dye comprising the pyrazolotriazole azomethine derivative.

Moreover, in another aspect of the present invention, a thermal transfer sheet comprising a substrate and a thermal transfer colorant layer comprising a dye and a binder resin on one surface of the substrate,
There is also provided a thermal transfer sheet, wherein the dye comprises the pyrazolotriazole azomethine derivative.

  According to the present invention, a pyrazolotriazole-based azomethine derivative that is inexpensive and excellent in light resistance can be realized. Moreover, according to the production method of the present invention, a pyrazolotriazole-based azomethine derivative can be produced by a simple and inexpensive method.

  Hereinafter, the pyrazolotriazole azomethine derivative according to the present invention will be described.

式中、Ｒ_１は、アルキル基またはアリール基を表す。アルキル基としては、分岐鎖を有してもよい炭素数１〜６のアルキル基が好ましく、アリール基は置換基を有していてもよい。 The pyrazolotriazole-based azomethine derivative according to the present invention is represented by the following formula I.

In the formula, R ₁ represents an alkyl group or an aryl group. As an alkyl group, the C1-C6 alkyl group which may have a branched chain is preferable, and the aryl group may have a substituent.

Among these, when R ₁ is an alkyl group, it is preferably an alkyl group having 1 to 4 carbon atoms, and particularly R ₁ is preferably a t-butyl group having a branched chain.

R ₂ represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, a carbonyl group, an alkoxycarbonyl group, a cyano group, a carbamoyl group, an arylamine group, an arylnitro group, or an arylamide group. These groups may further have a substituent. In a preferred embodiment, R ₂ is an alkyl group, an arylnitro group, or an arylamide group. Among these, R ₂ is more preferably a methyl group from the viewpoint of production cost, and the production is easy. From the viewpoint of properties, it is more preferably an N-substituted aryl group.

R ₃ represents a hydrogen atom or an alkyl group, and the alkyl group is preferably an alkyl group having 1 to 4 carbon atoms. Among these, a methyl group is more preferable.

Y _{1 to} Y ₄ each independently represent a nitrogen atom or a carbon atom substituted with CH or R _3, and at least one of Y _{1 to} Y ₄ is a nitrogen atom. That is, as an azomethine linking group to the 1H-pyrazolo [5,1-b] [1,2,4] triazole ring compound, any one of pyridyl groups (Y _{1 to} Y ₄ is a nitrogen atom; All carbon atoms), pyrazinyl groups (any one of Y _{1 to} Y ₄ is a nitrogen atom, all other carbon atoms), triazinyl groups (any one of Y _{1 to} Y ₄ are nitrogen atoms, Y any one of carbon atoms ₁ to Y _4), although all tetrazinyl group (Y ₁ to Y ₄ are mentioned nitrogen atom), it is preferable among these is a pyridyl group. In the present invention, an excellent azomethine-binding group to the 1H-pyrazolo [5,1-b] [1,2,4] triazole ring compound is not an aryl group but a nitrogen-containing cyclic substituent, thereby providing excellent light resistance. This is a combination of high cost and low manufacturing cost.

A pyrazolotriazole-based azomethine derivative according to the present invention includes a 1H-pyrazolo [5,1-b] [1,2,4] triazole coupler represented by the following formula II, a compound represented by the following formula, as shown in the following synthesis scheme: The compound III can be obtained by oxidative coupling reaction in the presence of sodium persulfate.

  The coupler 1H-pyrazolo [5,1-b] [1,2,4] triazole can be easily obtained by the methods described in JP-A Nos. 64-6274 and 8-109181. .

  These couplers used in the present invention can be synthesized or obtained at a very low cost as compared with 1H-pyrazolo [5,1-C] [1,2,4] triazole couplers. Therefore, a pyrazolotriazole azomethine dye represented by the formula I can be synthesized inexpensively and easily according to the above synthesis scheme.

(Thermal transfer sheet)
Next, the thermal transfer sheet according to the present invention will be described.

  The thermal transfer sheet according to the present invention comprises a base material and a heat transferable color material layer comprising a dye and a binder resin on one surface of the base, and the above-described novel pyrazolotriazole azomethine is used as the dye. It comprises a derivative.

  The base material can be the same base material as that used in conventional thermal transfer sheets, and is not particularly limited. Specific examples of preferable base materials include glass paper, condenser paper, thin paper such as paraffin paper, polyethylene terephthalate, polyphenylene sulfide, polyether ketone, polyether sulfone and other high heat resistant polyester, polypropylene, polycarbonate, cellulose acetate, Examples thereof include stretched or unstretched films of plastics such as polyethylene derivatives, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, polymethylpentene, and ionomer, and laminates of these materials.

  Although the thickness of a base material can be suitably selected according to material so that intensity | strength, thermal conductivity, heat resistance, etc. may become appropriate, the thing about 1-100 micrometers is normally used normally. When the substrate is poorly adhered to the heat transferable color material layer formed on this surface, it is preferable to subject the surface to primer treatment (formation of a primer layer) or corona treatment.

  In the present invention, the above-described dye is used as the thermal transfer recording dye contained in the heat transferable color material layer provided on one surface of the substrate, but may contain other known dyes. As the other dyes, any conventionally known dyes that are sublimable or heat diffusible can be appropriately used.

  Specific examples of sublimable or heat diffusible dyes include various kinds of non-azo compounds such as azo, anthraquinone, nitro, styryl, naphthoquinone, quinophthalone, azomethine, coumarin, and condensed polycyclic compounds. Examples include ionic dyes.

The binder resin used for the heat transferable colorant layer is a water-soluble polymer such as cellulose, polyacrylic acid, polyvinyl alcohol, or polyvinylpyrrolidone, acrylic resin, methacrylic resin, polystyrene, polycarbonate, polysulfone, polyethersulfone, polyvinyl. Examples thereof include polymers soluble in organic solvents such as butyral, polyvinyl acetal, ethyl cellulose, and nitrocellulose. Among these resins, polyvinyl butyral, polyvinyl acetal or cellulose resin having excellent storage stability is preferable. When using a polymer that is soluble in an organic solvent, one or more polymers may be used in the form of a latex dispersion in addition to being used by dissolving them in an organic solvent. The amount of the binder resin used is preferably 0.1 g to 50 g per 1 m ² of the base material.

  In order to improve the releasability from the image receiving layer, a release agent may be added or a release layer may be provided. As the release agent, reactive curable silicones, phosphate ester surfactants, fluorine compounds, and the like can be used. As for the usage-amount of a mold release agent, 0.5-40 mass% is preferable with respect to solid content of the layer to contain. When providing a release layer, the same binder as that used for the dye-donating layer can be used.

  The heat transferable color material layer is obtained by, for example, preparing a heat transferable color material layer forming ink by dissolving and mixing or dispersing a dye and a binder resin in a solvent, and applying and drying the ink on a base film.

  Solvents used in this ink include aromatic solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ester solvents such as ethyl acetate and butyl acetate; isopropanol, butanol and methyl cellosolve And alcohol solvents such as dioxane and tetrahydrofuran; amide solvents such as dimethylformamide and N-methylpyrrolidone. The ink may contain various conventionally known additives as required.

  The thickness of the heat transferable color material layer formed on the substrate is usually 0.1 μm or more, preferably 0.3 μm or more and 10 μm or less, preferably 5 μm or less after drying. The dye content in the heat transferable color material layer is 5% by weight or more, preferably 20% by weight, based on the total solid content of the heat transferable color material layer (component excluding the solvent from the heat transferable color material layer ink). As mentioned above, it is 70 weight% or less, Preferably it is 60 weight% or less.

  Further, a heat-resistant slipping phase may be provided on the other surface of the substrate (the surface opposite to the surface provided with the heat transferable color material layer). The thickness of the heat resistant slipping layer is usually 0.1 μm or more, preferably 0.3 μm or more and 10 μm or less, preferably 5 μm or less.

  The heat resistant slipping layer usually contains additives such as a binder resin, fine particles and a lubricant. As the binder resin, a binder resin made of a thermosetting resin, a photocurable resin, a thermoplastic resin, or the like is used.

  Examples of the thermosetting resin include an active hydrogen-containing resin such as ethyl cellulose resin, cellulose acetate resin, polyvinyl alcohol resin, polyvinyl acetoacetal resin, and polyvinyl butyral resin, and a crosslinked product such as isocyanate. Examples of the photocurable resin include polyester acrylate resin, epoxy acrylate resin, polyol acrylate resin, and the like. Examples of the thermoplastic resin include thermoplastic resins having a glass transition temperature of 50 ° C. or more. Specifically, acrylic resins, vinyl chloride copolymers, acrylonitrile-styrene copolymers, polycarbonate resins, polyester resins, polyvinyl butyral resins, A polyacetal resin etc. are mentioned.

  Examples of the fine particles include inorganic particles such as silica, alumina, and titanium oxide, and organic fine particles such as silicone resin, urea resin, and benzoguanamine resin.

  As the lubricant, various modified silicone oils, phosphate ester-based, fatty acid metal salt-based surfactants and the like are used. In addition, additives such as organic or inorganic non-sublimable particles, a dispersant, an antistatic agent, an antiblocking agent, an antifoaming agent, an antioxidant and a viscosity modifier are added to the heat resistant slipping layer as necessary. be able to.

  Furthermore, when energy rays such as laser beams are used for thermal transfer recording, a photothermal conversion material is contained in the thermal transferable color material layer, or a photothermal conversion material-containing layer is provided between the thermal transferable color material layer and the base film. Just do it. Examples of the photothermal conversion material include an infrared absorber and carbon black.

  The formation method of each layer, such as a heat transferable color material layer and a heat-resistant slip layer provided on these substrates, is arbitrary, and the formation thereof may be performed sequentially or simultaneously. Generally, it is formed by applying and drying a composition of a heat transferable color material layer or a heat resistant slipping layer. As this coating method, for example, any conventionally known method such as a gravure coater, a reverse coater, an air doctor coater or the like can be used.

(Thermal transfer recording method, recording material)
The thermal transfer sheet of the present invention can be subjected to a conventionally known thermal transfer recording method to perform thermal transfer recording. As a heat source for transferring the dye in the heat transferable color material layer onto the recording material, a line type thermal head or a laser beam can be used.

  The thermal transfer sheet according to the present invention can form an image on any conventionally known recording material for thermal transfer recording. The recording material is usually provided with an image receiving layer on at least one surface of the substrate. As the base material, a synthetic paper, cellulose paper, cast coated paper, film, or cellulose paper bonded with synthetic paper is usually used. The higher the adhesion to the color material layer, the more uniformly the dye is transferred during recording. Therefore, it is preferable that the surface be smooth, and if possible, use a substrate having a Beck smoothness of 10,000 seconds or more. preferable. In this respect, a base material using synthetic paper or a film is preferable.

  The image receiving layer is a layer mainly composed of a resin, and has a function of accepting a dye to form an image. As the resin, a resin that is easily dyed is preferable. For example, vinyl acetate resin, vinyl chloride resin, polyester resin, acrylonitrile-styrene resin, polyvinyl acetal resin and the like can be mentioned. These can be used in combination. If a resin having a glass transition point that is too low is used, an image may bleed during storage, and therefore it is preferable to use a resin having a glass transition point of 35 ° C. or higher.

  In addition to the resin, an additive can be added to the image receiving layer as necessary. As additives, curing agents such as isocyanate to cure the resin, release agents such as silicone added to prevent fusion with the color material layer during thermal transfer, ultraviolet absorbers to increase light resistance, Antioxidants for improving weather resistance can be mentioned.

Example 1
(Synthesis of dye)
The following compound A-1 was produced by the method described in JP-A No. 64-6274. Further, PYCD (P.I. Industries) was used as the following compound B-1.

1.78 g (0.01 mol) of compound A-1 and 3.03 g (0.12 mol) of compound B-1 were dissolved in 50 ml of methanol, and 2.79 g (0.07 mol) of caustic soda was dissolved in this solution. 10 ml of an aqueous solution and 80 ml of an aqueous solution of 5.95 g (0.025 mol) of sodium persulfate were added dropwise and stirred at room temperature for 1 hour. After stirring, the precipitated crystals were collected by filtration. The obtained crystals were suspended in 250 ml of water. Then, it was dissolved in 40 ml of THF solution and transferred to 280 ml of methanol solution to obtain 2.53 g (yield 72%) of the target compound 1.

With respect to the obtained compound, 1H-NMR and mass spectrum measurements were performed, and it was confirmed that the obtained compound had the structure of Compound 1. NMR measurement results (CDCl ₃ ) were as follows. δ (ppm): 9.23 (2H, d), 6.63 (2H, d), 3.67 (4H, m), 2.68 (3H, s), 2.51 (3H, s), 1.55 (9H, s), 1.32 (6H, t)

(Preparation of thermal transfer sheet)
The ink obtained by mixing and stirring 2.5 parts by weight of the dye obtained above, 3.5 parts by weight of polyvinyl acetal resin, 47 parts by weight of toluene, and 47 parts by weight of methyl ethyl ketone as the heat transferable color material layer ink composition Then, using a bar coater on a 4 μm thick substrate (4WF597, manufactured by Toray Industries, Inc.), the coating amount was 0.5 g / m ² and dried to prepare a thermal transfer sheet.

(Production of image receiving paper)
20 parts of vinyl chloride-vinyl acetate copolymer resin (Solvine C, manufactured by Nissin Chemical Industry), 2 parts of epoxy-modified silicone (X-22-3000T, manufactured by Shin-Etsu Chemical Co., Ltd.), toluene / methyl ethyl ketone (1: 1 mixture) ) The composition obtained by mixing and stirring 78 parts of the composition was obtained by using a bar coater on a polypropylene synthetic paper (trade name: YUPO FPG150, manufactured by YUPO Corporation) with a thickness of 150 μm, so that the film thickness after drying was 5 μm. Then, it was coated, dried, and further treated in an oven at 80 ° C. for 12 hours to obtain an image receiving paper.

(Printing conditions)
Using the produced thermal transfer sheet, printing was performed on the image receiving paper by a thermal transfer printer (CP740, manufactured by Canon).

(Light resistance evaluation test)
The printed matter was irradiated with a xenon fade meter (CI4000, manufactured by Atlas) at 200 kJ (420 nm integrated value) for 24 hours. CIRA soda lime was used as a filter.

For the printed matter before and after the light irradiation, the optical density was measured using a spectrocolorimeter (Spectrolino, manufactured by GretagMacbeth), and the density residual ratio was calculated by the following formula.
Concentration residual ratio = (optical density after irradiation) / (optical density before irradiation) × 100

  The results were as shown in Table 1 below.

Example 2
3.72 g (yield 69%) of Compound 2 was obtained in the same manner as in Example 1 except that the following Compound A-2 was used instead of Compound A-1.

  Compound A-2 was produced by the method described in JP-A-8-109181.

1H-NMR and mass spectrum measurement were performed, and it was confirmed that the obtained compound had the structure of Compound 2.

  Using the obtained compound 2, a light resistance evaluation test was conducted in the same manner as in Example 1. The obtained results were as shown in Table 1 below.

Example 3
2.84 g (yield 53%) of Compound 3 was obtained in the same manner as in Example 1 except that the following Compound A-3 was used instead of Compound A-1.

  Compound A-3 was produced by the method described in JP-A-8-109181.

1H-NMR and mass spectrum measurement were performed, and it was confirmed that the obtained compound had the structure of Compound 3.

  Using the obtained compound 3, a light resistance evaluation test was conducted in the same manner as in Example 1. The obtained results were as shown in Table 1 below.

Example 4
2.15 g (yield 47%) of Compound 4 was obtained in the same manner as in Example 1 except that the following Compound A-4 was used instead of Compound A-1.

  Compound A-4 was produced by the method described in JP-A-8-109181.

1H-NMR and mass spectrum measurement were performed, and it was confirmed that the obtained compound had the structure of Compound 4.

  Using the obtained compound 4, a light resistance evaluation test was conducted in the same manner as in Example 1. The obtained results were as shown in Table 1 below.

Example 5
1.72 g (yield 32%) of Compound 5 was obtained in the same manner as in Example 1 except that the following Compound A-5 was used instead of Compound A-1.

  Compound A-5 was produced by the method described in JP-A-8-109181.

1H-NMR and mass spectrum measurement were performed, and it was confirmed that the obtained compound had the structure of Compound 5.

  Using the obtained compound 5, a light resistance evaluation test was performed in the same manner as in Example 1. The obtained results were as shown in Table 1 below.

Example 6
2.27 g (43% yield) of Compound 6 was obtained in the same manner as in Example 1 except that the following Compound A-6 was used instead of Compound A-1.

  Compound A-6 was produced by the method described in JP-A-8-109181.

1H-NMR and mass spectrum measurement were performed, and it was confirmed that the obtained compound had the structure of Compound 6.

  Using the obtained compound 6, the light resistance evaluation test was conducted in the same manner as in Example 1. The obtained results were as shown in Table 1 below.

Example 7
1.23 g (yield 33%) of Compound 7 was obtained in the same manner as in Example 1 except that the following Compound A-7 was used instead of Compound A-1.

  Compound A-7 was obtained by the following reaction according to the method described in JP-A-8-109181.

1H-NMR and mass spectrum measurement were performed, and it was confirmed that the obtained compound had the structure of Compound 7.

  Using the obtained compound 7, a light resistance evaluation test was conducted in the same manner as in Example 1. The obtained results were as shown in Table 1 below.

Comparative Example 1
A light resistance evaluation test was performed in the same manner as in Example 1 except that a magenta dye represented by the following formula (D-9 dye described in Examples of Japanese Patent No. 3013137) was used as the dye. The obtained results were as shown in Table 1 below.

Comparative Example 2
Except for changing the light irradiation intensity to 200 kJ (420 nm integrated value) using a magenta dye represented by the following formula (a dye synthesized according to the method described in the example of Japanese Patent No. 3013137) as the dye, A light resistance evaluation test was conducted in the same manner as in Example 1. The obtained results were as shown in Table 1 below.

Claims (6)

A pyrazolotriazole azomethine derivative represented by the following formula I:

(Where
R ₁ represents an alkyl group or a phenyl group which may have a branched chain,
R ₂ represents an arylnitro group or an arylamide group,
R ₃ represents a hydrogen atom or an alkyl group,
Y _{1 to} Y ₄ each independently represent a nitrogen atom or CH, but at least one of Y _{1 to} Y ₄ is a nitrogen atom. ). The derivative according to claim 1, wherein R _{1 of} formula I is an alkyl group having a branched chain. The R _{2 in the} formula I is selected from the group consisting of the following (i) to (v) (wherein, * represents a bonding position with a pyrazolotriazole ring) . Derivatives described in 1.

A method for producing the derivative according to any one of claims 1 to 3, wherein a compound represented by the following formula II and a compound represented by the following formula III are reacted in the presence of sodium persulfate. Comprising a method.

(In the formula, R _{1 to} R ₃ and Y _{1 to} Y ₄ are the same as defined above.)   A thermal transfer recording dye comprising the pyrazolotriazole-based azomethine derivative according to any one of claims 1 to 3. A thermal transfer sheet comprising a base material and a thermal transferable color material layer comprising a dye and a binder resin on one surface of the base material,
The thermal transfer sheet in which the said pigment | dye comprises the pyrazolotriazole type | system | group azomethine derivative as described in any one of Claims 1-3.