JP2012213885A - Thermal transfer sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer sheet capable of achieving neutral black color as color mixture and obtaining printed matter superior in light resistance.SOLUTION: This thermal transfer sheet includes at least a yellow dye layer, a magenta dye layer, and a cyan dye layer. A dye layer including a dye coloring material and a binder resin is provided on a substrate, in the yellow dye layer, the magenta dye layer and the cyan dye layer. The yellow dye includes a dye coloring material comprising a thiazole methine compound, the magenta dye includes at least one kind of dye coloring material selected from a group consisting of azomethine compound, and the cyan dye includes at least one dye kind of coloring material selected from a group consisting of indoaniline compound.

Description

  The present invention relates to a thermal transfer sheet using a sublimation dye, more particularly to a thermal transfer sheet using a thermal transfer recording dye comprising a novel thiazolemethine compound, and more particularly to a neutral black In addition, the present invention relates to a thermal transfer sheet using a novel dye for thermal transfer recording, which is capable of realizing the above and has excellent light resistance.

  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, in JP-A-2-215595, in a thiazolemethine compound having a structure in which a substituted thiazole ring and a substituted pyrazoline ring are bonded by a methine chain, the 3-position of the pyrazoline ring is substituted with an amino group or an alkoxy group. For example, as compound 2, the 2-position of the thiazole ring is substituted with a diphenylamino group, and the 1-position of the pyrazoline ring is a phenyl group. A thiazolemethine compound substituted and substituted at the 3-position with an ethoxy group is disclosed.

  In addition to the development of yellow, magenta, and cyan color dyes, various research and development have been conducted on combinations of these color dyes. For example, Japanese Patent Application Laid-Open Nos. 7-96675 and 7-232481 disclose thermal transfer in which a print having excellent light resistance is obtained by combining a specific yellow dye, magenta dye, and cyan dye. A sheet has been proposed.

JP-A-2-215595 JP-A-7-96675 Japanese Patent Application Laid-Open No. 7-232481

  The present inventors have been able to achieve a neutral black as a mixed color of these by combining a specific yellow dye, magenta dye, and cyan dye, and a thermal transfer product that is excellent in light resistance can be obtained. The knowledge that the sheet can be realized was obtained. The present invention is based on this finding.

  Accordingly, an object of the present invention is to provide a thermal transfer sheet capable of realizing a neutral black color mixture and obtaining a printed matter having excellent light resistance.

（式中、
Ｒ_１およびＲ_２は、それぞれ独立して、Ｃ１〜Ｃ４のアルキル基を表し、
Ｒ_３は、水素原子または分岐を有していてもよいＣ１〜Ｃ８のアルキル基を表し、
Ｒ_４は、Ｃ１〜Ｃ４のアルキル基を表す。）
前記マゼンタ染料は、下記式（M-I）で表される化合物、下記式（M-II）で表される化合物、および下記式（M-III）で表される化合物からなる群から選択される少なくとも１種の染料色素を含んでなり、

（式中、
環Ａは、置換基を有しても良いピリジン環を表し、
Ｒ_５およびＲ_６は、それぞれ独立して、水素原子、置換されても良いアルキル基、アリル基、置換されても良いアリール基または置換されても良いシクロアルキル基を表し、
Ｒ_７は、置換されても良いアルキル基または置換されても良いアリール基を表し、
Ｒ_８は、水素原子、置換されても良いアルキル基または置換されても良いアリール基を表す。）

（式中、
環Ｅは、置換基を有しても良いピリジン環を表し、
Ｒ_９およびＲ_１０は、それぞれ独立して、水素原子、置換されても良いアルキル基、アリル基、置換されても良いアリール基または置換されても良いシクロアルキル基を表し、
Ｒ_１１は、水素原子、置換されても良いアルキル基、置換されても良いアリール基、アルコキシ基、アルコキシカルボニル基、シアノ基またはカルバモイル基を表し、
Ｒ_１２は、置換されても良いアルキル基または置換されても良いアリール基を表す。）

（式中、
Ｒ_１３およびＲ_１４は、それぞれ独立して、アミノ基またはヒドロキシ基を表し、
Ｒ_１５およびＲ_１６は、それぞれ独立して、水素原子または置換されても良いアリールオキシ基を表す。）
前記シアン染料は、下記式（C-I）で表される化合物および下記式（C-II）で表される化合物からなる群から選択される少なくとも１種の染料色素を含んでなる、

（式中、
環Ｇは、任意の置換基を有しても良いベンゼン環を表し、
Ｒ_１７およびＲ_１８は、それぞれ独立して、水素原子、置換されても良いアルキル基、アリル基、置換されても良いアリール基または置換されても良いシクロアルキル基を表し、
Ｒ_１９は、水素原子または置換されても良いアルキル基を表し、
Ｒ_２０は、置換されても良いアルキル基、置換されても良いアルコキシ基、置換されても良いアリール基または置換されても良いアリールオキシ基を表し、
Ｒ_２１は、水素原子またはハロゲン原子を表す。）

（式中、Ｒ_２２およびＲ_２３は、それぞれ独立して、水素原子、置換されても良いアルキル基または置換されても良いアリール基を表す。）
ことを特徴とするものである。 The thermal transfer sheet according to the present invention is a thermal transfer sheet comprising at least a yellow dye layer, a magenta dye layer, and a cyan dye layer,
Each of the yellow dye layer, the magenta dye layer, and the cyan dye layer is provided with a dye layer comprising a dye pigment and a binder resin on a substrate.
The yellow dye comprises a dye pigment composed of a compound represented by the following formula (YI):

(Where
R ₁ and R ₂ each independently represent a C1-C4 alkyl group,
R ₃ represents a hydrogen atom or a C1-C8 alkyl group which may have a branch,
R ₄ represents a C1-C4 alkyl group. )
The magenta dye is at least selected from the group consisting of a compound represented by the following formula (MI), a compound represented by the following formula (M-II), and a compound represented by the following formula (M-III). Comprising one dye pigment,

(Where
Ring A represents a pyridine ring which may have a substituent,
R ₅ and R ₆ each independently represent a hydrogen atom, an optionally substituted alkyl group, an allyl group, an optionally substituted aryl group or an optionally substituted cycloalkyl group;
R ₇ represents an optionally substituted alkyl group or an optionally substituted aryl group;
R ₈ represents a hydrogen atom, an optionally substituted alkyl group or an optionally substituted aryl group. )

(Where
Ring E represents a pyridine ring which may have a substituent,
R ₉ and R ₁₀ each independently represent a hydrogen atom, an optionally substituted alkyl group, an allyl group, an optionally substituted aryl group or an optionally substituted cycloalkyl group;
R ₁₁ represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, an alkoxy group, an alkoxycarbonyl group, a cyano group or a carbamoyl group,
R ₁₂ represents an optionally substituted alkyl group or an optionally substituted aryl group. )

(Where
R ₁₃ and R ₁₄ each independently represents an amino group or a hydroxy group,
R ₁₅ and R ₁₆ each independently represent a hydrogen atom or an optionally substituted aryloxy group. )
The cyan dye comprises at least one dye pigment selected from the group consisting of a compound represented by the following formula (CI) and a compound represented by the following formula (C-II).

(Where
Ring G represents a benzene ring optionally having a substituent,
R ₁₇ and R ₁₈ each independently represent a hydrogen atom, an optionally substituted alkyl group, an allyl group, an optionally substituted aryl group or an optionally substituted cycloalkyl group;
R ₁₉ represents a hydrogen atom or an optionally substituted alkyl group,
R ₂₀ represents an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aryl group or an optionally substituted aryloxy group,
R ₂₁ represents a hydrogen atom or a halogen atom. )

(In the formula, R ₂₂ and R ₂₃ each independently represent a hydrogen atom, an optionally substituted alkyl group or an optionally substituted aryl group.)
It is characterized by this.

  The thermal transfer sheet according to the present invention realizes a neutral black as a color mixture of these by combining a yellow dye, a magenta dye, and a cyan dye, and a thermal transfer sheet from which a printed matter with excellent light resistance can be obtained. it can.

  The thermal transfer sheet according to the present invention is a thermal transfer sheet comprising at least a yellow dye layer, a magenta dye layer, and a cyan dye layer, wherein each of the yellow dye layer, the magenta dye layer, and the cyan dye layer is formed on a substrate. And a dye layer comprising a dye pigment and a binder resin. Hereinafter, each layer constituting the thermal transfer sheet will be described.

<Base material>
The base material constituting the thermal transfer sheet according to the present invention is for supporting a dye layer described later, and a known material can be used. Specifically, any one having a conventionally known heat resistance and strength may be used. For example, polyethylene terephthalate film, 1,4-polycyclohexylenedimethylene terephthalate film, polyethylene naphthalate film, polyphenylene Sulfide film, polystyrene film, polypropylene film, polysulfone film, aramid film, polycarbonate film, polyvinyl alcohol film, cellophane, cellulose derivatives such as cellulose acetate, polyethylene film, polyvinyl chloride film, nylon film, polyimide film, ionomer film, etc. Resin film; Papers such as condenser paper, paraffin paper, and synthetic paper; Nonwoven fabric; Composite of paper, nonwoven fabric and resin, and the like.

  The substrate generally has a thickness of about 0.5 to 50 μm, preferably about 3 to 10 μm.

  The substrate may be subjected to an adhesion treatment on one side or both sides as necessary. When the dye ink for forming the dye layer is applied on the base material, it is preferable to perform an adhesion treatment because the wettability and adhesiveness of the coating liquid are likely to be insufficient. Examples of the above-mentioned adhesion treatment include corona discharge treatment, flame treatment, ozone treatment, ultraviolet treatment, radiation treatment, surface roughening treatment, chemical treatment, plasma treatment, low temperature plasma treatment, primer treatment, grafting treatment, etc. The reforming technique can be applied as it is. Two or more of these treatments can be used in combination.

  Furthermore, it is also possible to apply and form an adhesive layer on the base material as the base material adhesion treatment. An adhesion layer can be formed from the following organic materials and inorganic materials, for example. Examples of the organic material include polyester resins, polyacrylate resins, polyvinyl acetate resins, polyurethane resins, styrene acrylate resins, polyacrylamide resins, polyamide resins, polyether resins, polystyrene resins, Examples thereof include polyethylene resins, polypropylene resins, polyvinyl chloride resins and polyvinyl alcohol resins, vinyl resins such as polyvinyl pyrrolidone and modified products thereof, and polyvinyl acetal resins such as polyvinyl acetoacetal and polyvinyl butyral. Examples of the inorganic material include silica (colloidal silica), alumina or alumina hydrate (alumina sol, colloidal alumina, cationic aluminum oxide or hydrate, suspicion bakumaite, etc.), aluminum silicate, magnesium silicate, magnesium carbonate, oxidation Examples include colloidal inorganic pigment ultrafine particles such as magnesium and titanium oxide.

  The primer treatment may be performed by applying a primer solution to an unstretched film and then stretching the plastic film when the plastic film is produced by stretching.

<Dye layer>
The thermal transfer sheet according to the present invention is obtained by forming at least a yellow dye layer, a magenta dye layer, and a cyan dye layer as a dye layer on a substrate. The transfer sheet may further form a conventionally known black dye layer as the dye layer.

  The thermal transfer sheet may be one in which each dye layer is formed in the surface order on the substrate. For example, a substrate sheet in which a plurality of dye layers such as yellow, magenta, cyan, and black are repeatedly provided in a surface sequence, a transfer protective layer is provided in a surface sequence in addition to the plurality of dye layers, and the like. Also good. In addition, you may provide black of a heat-meltable ink layer further.

<Yellow dye pigment>
The yellow dye layer comprises a yellow dye coloring matter represented by the following formula (YI) and a binder resin. Is.

In the formula (YI), R ₁ and R ₂ each independently represent a C1-C4 alkyl group. Among these, from the viewpoint of sensitivity, R ₁ and R ₂ are both C2-C3. An alkyl group is preferred.

In the above formula (YI), R ₃ represents a hydrogen atom or a C1-C8 alkyl group which may have a branch. Among these, from the viewpoint of sensitivity and light resistance, R ₃ is C2 It is preferably a C4 alkyl group, more preferably an isopropyl group.

In the formula (YI), R ₄ represents a C1-C4 alkyl group, and among these, R ₄ is preferably an ethyl group.

The thiazole methine compound which is a yellow dye pigment represented by the above formula (YI) can be synthesized by a dehydration condensation reaction between a thiazole aldehyde compound and a pyrazolone compound. For example, a thiazole aldehyde compound represented by the following formula (I) and a pyrazolone compound represented by the following formula (II) are heated in a solvent such as 2-propanol for dehydration condensation, whereby the above formula ( A thiazolemethine compound represented by YI) can be synthesized. In the following formulas (I) and (II), R ₁ , R ₂ , R ₃ and R ₄ are all as defined above.

  The thiazole aldehyde compound of the above formula (I) used for the production of the thiazole methine compound represented by the above formula (YI) can be synthesized by a known method, for example, described in German Patent No. 1137024 It can be synthesized by the method. The pyrazolone compound of the above formula (II) can also be synthesized by a known method, for example, by the method described in JP-A-51-52169.

  In the present invention, in the present invention, a dye dye other than the above may be used in combination with the yellow dye dye in addition to the above. For example, known yellow dye pigments such as diarylmethane pigments; triarylmethane pigments; thiazole pigments; merocyanine pigments; methine pigments such as pyrazolone methine; indoaniline pigments; acetophenone azomethine, pyrazoloazomethine, imidazole Azomethine dyes represented by azomethine, imidazoazomethine and pyridone azomethine; xanthene dyes; oxazine dyes; cyanostyrene dyes represented by dicyanostyrene and tricyanostyrene; thiazine dyes; azine dyes; acridine dyes; Benzene azo dyes; azo dyes such as pyridone azo, thiophenazo, isothiazole azo, pyrrole azo, pyral azo, imidazole azo, thiadiazole azo, triazole azo, and dizazo; spiropyran dyes Indian Linus Piropi run based dyes; fluoran dyes; rhodamine lactam-based dyes; naphthoquinone dyes; anthraquinone dyes; quinophthalone dyes, etc. may be used. In the present invention, it is particularly preferable to use a quinophthalone dye in combination with the above. By using these dyes in combination, the target hue can be brought closer, and the light resistance is further improved.

<Magenta dye pigment>
The magenta dye layer comprises at least one magenta dye pigment selected from the group consisting of compounds represented by the following formulas (MI), (M-II) and (M-III), and a binder resin. Is. Hereinafter, each magenta dye coloring matter represented by the following formulas (MI), (M-II) and (M-III) will be described.

上記式中、環Ａは、置換基を有しても良いピリジン環を表し、Ｒ_５およびＲ_６は、それぞれ独立して、水素原子、置換されても良いアルキル基、アリル基、置換されても良いアリール基または置換されても良いシクロアルキル基を表し、Ｒ_７は、置換されても良いアルキル基または置換されても良いアリール基を表し、Ｒ_８は、水素原子、置換されても良いアルキル基または置換されても良いアリール基を表すが、本発明においては、下記式（M-I-I）で表されるアゾメチン系染料色素を好適に使用することができる。

In the above formula, ring A represents an optionally substituted pyridine ring, and R ₅ and R ₆ are each independently a hydrogen atom, an optionally substituted alkyl group, an allyl group, or a substituted group. Represents an optionally substituted aryl group or an optionally substituted cycloalkyl group, R ₇ represents an optionally substituted alkyl group or an optionally substituted aryl group, and R ₈ represents a hydrogen atom or an optionally substituted group. In the present invention, an azomethine dye coloring matter represented by the following formula (MII) can be preferably used.

  The azomethine dye coloring matter represented by the above formula (M-I-I) can be produced by the method described in Japanese Patent No. 3013137.

で表される染料色素において、環Ｅは、置換基を有しても良いピリジン環を表し、Ｒ_９およびＲ_１０は、それぞれ独立して、水素原子、置換されても良いアルキル基、アリル基、置換されても良いアリール基または置換されても良いシクロアルキル基を表し、Ｒ_１１は、水素原子、置換されても良いアルキル基、置換されても良いアリール基、アルコキシ基、アルコキシカルボニル基、シアノ基またはカルバモイル基を表し、Ｒ_１２は、置換されても良いアルキル基または置換されても良いアリール基を表す。 In addition, the following formula (M-II):

Ring E represents a pyridine ring which may have a substituent, and R ₉ and R ₁₀ each independently represents a hydrogen atom, an alkyl group which may be substituted, or an allyl group. Represents an optionally substituted aryl group or an optionally substituted cycloalkyl group, R ₁₁ represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, an alkoxy group, an alkoxycarbonyl group, It represents a cyano group or a carbamoyl group, and R ₁₂ represents an optionally substituted alkyl group or an optionally substituted aryl group.

で表される染料色素において、Ｒ_１３およびＲ_１４は、それぞれ独立して、アミノ基またはヒドロキシ基を表し、Ｒ_１５およびＲ_１６は、それぞれ独立して、水素原子または置換されても良いアリールオキシ基を表すが、本発明においては、下記式（M-III-I）や（M-III-II）で表されるアントラキノン系染料色素を好適に使用することができる。 Further, the following formula (M-III):

R ₁₃ and R ₁₄ each independently represent an amino group or a hydroxy group, and R ₁₅ and R ₁₆ each independently represent a hydrogen atom or an optionally substituted aryloxy In the present invention, anthraquinone dye dyes represented by the following formulas (M-III-I) and (M-III-II) can be preferably used.

  Examples of the magenta dye coloring matter represented by the formula M-III-I include anthraquinone dyes such as Disperse Red 60, and examples of the magenta dye coloring matter represented by the formula M-III-II include Disperse Violet 26 and the like. And anthraquinone dyes.

  In the present invention, the aforementioned magenta dye pigments may be used in combination. In particular, it is preferable to use a combination of the dyes of the above formula (M-I-I), the above formula (M-III-I) and the above formula (M-III-II). By using these dyes in combination, the target hue can be brought closer, and the light resistance is further improved.

<Cyan dye layer>
The cyan dye layer includes at least one cyan dye pigment selected from the group consisting of a compound represented by the following formula (CI) and a compound represented by the following formula (C-II), and a binder resin. It will be. Hereinafter, each cyan dye coloring matter represented by the following formulas (CI) and (C-II) will be described.

で表される染料色素において、環Ｇは、任意の置換基を有しても良いベンゼン環を表し、Ｒ_１７およびＲ_１８は、それぞれ独立して、水素原子、置換されても良いアルキル基、アリル基、置換されても良いアリール基または置換されても良いシクロアルキル基を表し、Ｒ_１９は、水素原子または置換されても良いアルキル基を表し、Ｒ_２０は、置換されても良いアルキル基、置換されても良いアルコキシ基、置換されても良いアリール基または置換されても良いアリールオキシ基を表し、Ｒ_２１は、水素原子またはハロゲン原子を表すが、本発明においては、下記式（C-I-I）で表されるシアン染料色素を好適に使用することができる。 The following formula (CI):

Ring G represents a benzene ring which may have an arbitrary substituent, R ₁₇ and R ₁₈ each independently represent a hydrogen atom, an optionally substituted alkyl group, Represents an allyl group, an optionally substituted aryl group or an optionally substituted cycloalkyl group, R ₁₉ represents a hydrogen atom or an optionally substituted alkyl group, and R ₂₀ represents an optionally substituted alkyl group. Represents an optionally substituted alkoxy group, an optionally substituted aryl group or an optionally substituted aryloxy group, and R ₂₁ represents a hydrogen atom or a halogen atom. In the present invention, the following formula (CII The cyan dye coloring matter represented by) can be suitably used.

  The cyan dye coloring matter represented by the above formula (C-I-I) can be produced in the same manner as the indoaniline compound described in JP-B-5-45436.

で表される染料色素において、Ｒ_２２およびＲ_２３は、それぞれ独立して、水素原子、置換されても良いアルキル基または置換されても良いアリール基を表すが、本発明においては、下記式（C-II-I）で表されるシアン染料色素であるＳｏｌｖｅｎｔ Ｂｌｕｅ６３を好適に使用することができる。 In addition, the following formula (C-II):

In the present invention, R ₂₂ and R ₂₃ each independently represent a hydrogen atom, an optionally substituted alkyl group or an optionally substituted aryl group. In the present invention, the following formula ( Solvent Blue 63, which is a cyan dye coloring matter represented by C-II-I), can be preferably used.

  In the present invention, the above-mentioned cyan dye pigments may be used in combination. In particular, it is preferable to use a combination of dye pigments represented by the above formula (C-I-I) and the above formula (C-II-I). By using these dyes in combination, the target hue can be brought closer, and the light resistance is further improved.

  The content of various dyes depends on the combination of the base material and the primer, but the dye can obtain a sufficient density as an image (yellow, magenta, cyan reflection density 1.8 or more: when measuring ISO status A density). Content is preferred. The content range will be described later.

  Each of the dye layers contains a binder resin in addition to the specific dye. The binder resin is not particularly limited, and conventionally known ones can be used. For example, cellulose resins such as methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose acetate, cellulose butyrate; polyvinyl alcohol And vinyl resins such as polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone, and polyacrylamide; polyester resins; phenoxy resins, and the like.

  The binder resin further includes a releasable graft copolymer. The releasable graft copolymer can be blended as a release agent. The releasable graft copolymer has at least one releasable segment selected from a polysiloxane segment, a fluorocarbon segment, a fluorinated hydrocarbon segment, and a long-chain alkyl segment as a polymer main chain constituting the binder resin. Is obtained by graft polymerization. As the releasable graft copolymer, a graft copolymer obtained by grafting a polysiloxane segment to a main chain composed of polyvinyl acetal is particularly preferable.

  Each dye layer may use additives such as a release agent, inorganic fine particles, and organic fine particles, if desired. Examples of the release agent include the above-described releasable graft copolymer, silicone oil, and phosphate ester. Inorganic fine particles include carbon black, aluminum, molybdenum disulfide and the like. Examples of the organic fine particles include polyethylene wax.

  Each dye layer is formed from a dye ink containing a specific dye, a binder resin, an additive to be added as required, and a solvent. The solvent is not particularly limited as long as it is a conventionally known material for dye ink. For example, acetone, methanol, water, methyl ethyl ketone, toluene, ethanol, isopropyl alcohol, cyclohexanone, dimethylformamide (DMF), ethyl acetate, etc. A mixed solvent of these solvents can be used, and among them, a mixed solvent of methyl ethyl ketone and toluene is preferable.

  In the dye ink containing a yellow dye coloring matter, the yellow dye coloring matter is preferably 50 to 300 parts by mass, and more preferably 85 to 250 parts by mass with respect to 100 parts by mass of the binder resin. Moreover, in yellow dye ink, it is preferable that content of a yellow dye pigment | dye is 0.5-15 mass%. Further, the yellow dye ink is preferably 2 to 30% by mass, more preferably 5 to 15% by mass, based on the total amount of the dye such as yellow dye pigment and the binder resin, that is, the solid content. . In addition, when yellow dye ink contains 2 or more types of dye pigment | dyes, all the content and solid content of the said yellow dye represent the total amount of each dye pigment | dye.

  In the dye ink containing a magenta dye pigment, the content of the magenta dye pigment is preferably 50 to 300 parts by mass, more preferably 85 to 250 parts by mass with respect to 100 parts by mass of the binder resin. When the magenta dye pigment contains two or more dye pigments, the content and solid content of the magenta dye pigment both represent the total amount of each dye pigment.

  In the dye ink containing a cyan dye coloring matter, the content of the cyan dye coloring matter is preferably 50 to 300 parts by mass, more preferably 85 to 250 parts by mass with respect to 100 parts by mass of the binder resin. In the cyan dye ink, the total amount of the cyan dye coloring matter and the binder resin, that is, the solid content is preferably about 2 to 30% by mass, and more preferably 5 to 15% by mass. In addition, when the said cyan dye pigment | dye contains 2 or more types of dye pigment | dyes, both content and solid content of the said cyan dye pigment | dye represent the total amount of each dye pigment | dye.

  Each dye ink is, for example, a paint shaker, a propeller-type stirrer, a dissolver, a homomixer, a ball mill, a bead mill, a sand mill, a two-roll mill, a three-roll mill, an ultrasonic disperser, a kneader, a line mixer, a twin-screw extruder, etc. It can prepare using a well-known manufacturing method.

  Each dye layer can be formed, for example, by coating each of the above-described dye inks on the substrate by a conventionally known method such as wire bar coating, gravure printing, reverse roll coating using a gravure plate, or the like. it can.

  As the coating method, gravure coating is preferred. Moreover, in coating, it is although it does not specifically limit, It is preferable to dry for about 1 second-about 5 minutes at the temperature of 60-120 degreeC. Insufficient drying of each dye ink causes the dye ink to turn over when it is soiled or wound, and then retransfers to the dye layer that has a different hue when the turned dye ink is turned over. So-called kickback may occur.

Each dye ink may be applied so that the dry coating amount is preferably about 0.2 to 3.0 g / m ² , more preferably about 0.4 to 1.0 g / m ² .

<Other layers>
In the thermal transfer sheet according to the present invention, a heat-resistant slipping layer may be formed on the base material surface opposite to the surface on which each dye layer is formed. The heat resistant slipping layer is provided to prevent problems caused by heat of the thermal head during thermal transfer, such as sticking and printing wrinkles.

  The heat resistant slipping layer is mainly composed of a heat resistant resin. The heat resistant resin is not particularly limited. For example, polyvinyl butyral resin, polyvinyl acetoacetal resin, polyester resin, vinyl chloride-vinyl acetate copolymer resin, polyether resin, polybutadiene resin, styrene-butadiene copolymer resin, Acrylic polyol, polyurethane acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, urethane or epoxy prepolymer, nitrocellulose resin, cellulose nitrate resin, cellulose acetate propionate resin, cellulose acetate butyrate resin, cellulose acetate-hydrodiene Phthalate resin, cellulose acetate resin, aromatic polyamide resin, polyimide resin, polyamideimide resin, polycarbonate resin, chlorine Polyolefin resins.

  The heat resistant slipping layer may be formed by blending additives such as a slipperiness imparting agent, a crosslinking agent, a release agent, an organic powder, and an inorganic powder in addition to the above heat resistant resin.

In general, the heat-resistant slipping layer is prepared by adding the above-mentioned heat-resistant resin, and the above-described slipperiness-imparting agent and additives that are optionally added to the solvent, and dissolving or dispersing each component to thereby apply the heat-resistant slipping layer coating solution. Then, the heat resistant slipping layer coating solution can be coated on a substrate and dried.
As the solvent in the heat resistant slipping layer coating solution, the same solvent as that in the dye ink can be used.

Examples of the coating method of the heat resistant slipping layer coating liquid include wire bar coating, gravure printing, screen printing, reverse roll coating using a gravure plate, and gravure coating is particularly preferable. Heat-resistant slip layer coating solution, dry coating amount is preferably 0.1 to 3 g / ^{m 2,} more preferably may be applied so as to be 1.5 g / ^{m 2} or less.

  If the thermal transfer sheet of this invention has the above-mentioned dye layer on a base material, an undercoat layer etc. may be provided between the said base material and dye layer. The undercoat layer is not particularly limited, and a composition that improves the adhesion between the substrate and the dye layer can be appropriately selected and provided.

  The thermal transfer sheet according to the present invention may be one in which a transfer protective layer is further formed in the surface order with the above-mentioned dye layer so that a protective layer for protecting the image surface can be transferred after image formation. The configuration and preparation of the transfer protective layer are not particularly limited, and can be selected from conventionally known techniques according to the characteristics of the substrate sheet, the dye layer, and the like to be used. In addition, when the base film is not releasable, the transfer protective layer is preferably provided with a release layer between the base film and the transfer protective layer to improve the transfer property of the transfer protective layer.

  The thermal transfer sheet according to the present invention heats and presses a predetermined portion with a thermal head or the like on the side opposite to the side on which the dye layer is provided of the base material, and transfers the dye in the portion corresponding to the printing portion of the dye layer to the transfer material Can be printed.

  As the material to be transferred, a thermal transfer image receiving sheet or the like can be used. The thermal transfer image receiving sheet is provided with a dye receiving layer on one surface on a substrate. The base material layer constituting the thermal transfer image-receiving sheet has a function of holding the receiving layer, but since heat is applied at the time of thermal transfer, it preferably has a mechanical strength that does not hinder handling even in a heated state. . The material of the base material layer is not particularly limited, and examples thereof include capacitor paper, glassine paper, sulfuric acid paper, synthetic paper (polyolefin-based, polystyrene-based, etc.), high-quality paper, art paper, coated paper, Cast coated paper, wallpaper, backing paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internal paper, paperboard, cellulose fiber paper, silver salt photographic printing paper coated with polyethylene on both sides Resin-coated paper used as a base material, or polyester, polyacrylate, polycarbonate, polyurethane, polyimide, polyetherimide, cellulose derivative, polyethylene, ethylene-vinyl acetate copolymer, polypropylene, polystyrene, acrylic, polyvinyl chloride , Polyvinylidene chloride, etc. Seed plastic film or sheet can be used, also white pigment, these synthetic resins, formed by adding a filler, a film (porous film) having fine voids (microvoids) inside the substrate can also be used.

  The dye receiving layer provided on the base material layer is for receiving the sublimation dye transferred from the thermal transfer sheet and maintaining the formed image. As the resin for forming the receiving layer, polycarbonate resin, polyester resin, polyamide resin, acrylic resin, acrylic-styrene resin, cellulose resin, polysulfone resin, polyvinyl chloride resin, vinyl chloride- Acrylic resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate copolymer resin, polyvinyl acetal resin, polyvinyl butyral resin, polyurethane resin, polystyrene resin, polypropylene resin, polyethylene resin, ethylene-vinyl acetate copolymer Examples thereof include resins, epoxy resins, polyvinyl alcohol resins, gelatin and derivatives thereof. Two or more of these resin materials may be mixed and used.

  The thermal transfer image-receiving sheet may contain a release agent in the dye-receiving layer in order to improve releasability from the thermal transfer sheet. Various release agents such as solid waxes such as polyethylene wax, amide wax, Teflon (registered trademark), fluorine-based or phosphate-based surfactant, silicone oil, reactive silicone oil, curable silicone oil, etc. Examples thereof include silicone oil and various silicone resins.

  In addition, between the base material layer and the dye receiving layer, the purpose is to provide adhesion, whiteness, cushioning, concealing property, antistatic property, anti-curling property, etc. between the dye receiving layer and the base material. Any known intermediate layer can be provided. The binder resin used for the intermediate layer is polyurethane resin, polyester resin, polycarbonate resin, polyamide resin, acrylic resin, polystyrene resin, polysulfone resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride. -Vinyl acetate copolymer resin, polyvinyl acetal resin, polyvinyl butyral resin, polyvinyl alcohol resin, epoxy resin, cellulose resin, ethylene-vinyl acetate copolymer resin, polyethylene resin, polypropylene resin and the like.

  The present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples. “Part” means part by mass unless otherwise specified.

<Preparation of yellow ink>
The following five types of thiazolemethine compounds were synthesized as yellow dye pigments used in yellow ink.
Example 1: Synthesis of thiazolemethine compound 1 0.66 g 2-diethylamino-5-formylthiazole (3.6 mmol), 0.73 g 3-ethoxy-1-phenyl-5-pyrazolone (3.6 mmol) 0.28 g of ammonium acetate (3.6 mmol) was added to 5 ml of 2-propanol solvent and the mixture was stirred for 1.5 hours under heating to reflux. Subsequently, 2-propanol was concentrated and removed, 5 ml of water was added to the reaction system, the precipitated solid was collected by filtration, washed with water, and dried in an oven to obtain 1.26 g of Compound 1. The structure of the obtained compound 1 was identified using an infrared absorption spectrum analyzer and a nuclear magnetic resonance apparatus. From the analysis results of the IR spectrum and the proton NMR spectrum, it was confirmed that a thiazolemethine compound represented by the following formula was obtained.

Example 2: Synthesis of thiazolemethine compound 2 Instead of 0.66 g 2-diethylamino-5-formylthiazole, which is the starting material, 1.81 g 2-diethylamino-5-formyl-4-isopropylthiazole (8 mmol) 2.24 g of compound 2 was obtained in the same manner as in Example 1 except that it was used. When the structure of the obtained compound 2 was identified in the same manner as in Example 1, it was confirmed that a thiazolemethine compound represented by the following formula was obtained.

Example 3 Synthesis of Thiazolemethine Compound 3 Instead of 0.66 g 2-diethylamino-5-formylthiazole, which is the starting material, 1.36 g 2-dipropylamino-5-formyl-4-isopropylthiazole (5 .34 mmol) was used in the same manner as in Example 1 to obtain 1.96 g of Compound 3. When the structure of the obtained compound 3 was identified in the same manner as in Example 1, it was confirmed that the thiazolemethine compound represented by the following formula was obtained.

Comparative Example 1: Synthesis of thiazolemethine compound 4 Instead of 0.66 g of 2-diethylamino-5-formylthiazole, which is a starting material, 2.08 g of 2-diethylamino-5-formyl-4-phenylthiazole (8 mmol) was used. 3.28 g of compound 4 was obtained in the same manner as in Example 1 except that it was used. When the structure of the obtained compound 4 was identified in the same manner as in Example 1, it was confirmed that a thiazolemethine compound represented by the following formula was obtained.

Comparative Example 2: Synthesis of thiazolemethine compound 5 A compound similar to compound 2 described in Examples of JP-A-2-215595 was synthesized based on the description of JP-A-2-215595, and the following formula The thiazole methine compound 5 represented by this was obtained.

  2.5 parts of each compound obtained above, 70 parts of polyvinyl acetal resin (ESREC KS-5, 5% varnish, manufactured by Sekisui Chemical Co., Ltd.), and solvent of toluene / methyl ethyl ketone (mass ratio 1: 1) 27.5 parts were mixed to prepare yellow inks Y1 to Y5. The Y5 ink was in a suspended state because the dye was not completely dissolved in the solvent.

<Preparation of magenta ink>
As the magenta dye coloring matter, 2.0 parts of the azomethine dye coloring matter represented by the above formula (MII), 2.0 parts of Disperse Red 60 and 3.0 parts of Disperse Violet 26, polyvinyl acetal resin (ESREC KS-5, Magenta ink M1 was prepared by mixing 70 parts of 5% varnish, manufactured by Sekisui Chemical Co., Ltd.) and 23 parts of a solvent of toluene / methyl ethyl ketone (mass ratio 1: 1). The azomethine dye coloring matter represented by the above formula (MII) was produced by the method described in Japanese Patent No. 3013137.

<Preparation of cyan ink>
As cyan dye coloring matter, 3.0 parts of indoaniline dye coloring matter represented by the above formula (CII) and 4.0 parts of Solvent Blue 63, polyvinyl acetal resin (Eslek KS-5, 5% varnish, Sekisui Chemical Co., Ltd.) Cyanide ink C1 was prepared by mixing 70 parts by a company) and 23 parts of a toluene / methyl ethyl ketone (mass ratio 1: 1) solvent. The indoaniline dye pigment represented by the above formula (CII) was produced by the method described in Japanese Examined Patent Publication No. 5-45436.

<Preparation of thermal transfer sheet>
On one surface of a polyethylene terephthalate (PET) film having a thickness of 4.5 μm, a heat-resistant slip layer forming coating liquid having the following composition was applied so that the dry coating amount was 1.0 g / m ² , It was dried to form a heat resistant slipping layer. In addition, the following compounding quantity is a mass reference | standard. Next, on the surface opposite to the surface on which the heat-resistant slip layer of the PET film is formed, each ink obtained above is applied by gravure coating so that the dry coating amount is 0.8 g / m ² , The dye layer was formed by drying at 80 ° C. for 2 minutes.
<Coating liquid for forming heat resistant active layer>
Polyvinyl butyral resin (ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.)
13.6 parts polyisocyanate curing agent (Takenate D218, manufactured by Takeda Pharmaceutical Company Limited)
0.6 parts Phosphate ester (Pricesurf A208, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.8 parts Methyl ethyl ketone (MEK) 42.5 parts Toluene 42.5 parts

<Preparation of thermal transfer image receiving sheet>
An adhesive layer forming coating solution having the following composition was applied to one surface of a 39 μm-thick microvoided film of the fine void layer and dried to form an adhesive layer. Next, according to the formation conditions described later, a support having a back layer provided on one side of the coated paper (186 g / m ² ) and a microvoided film are provided on the side opposite to the side on which the back layer is provided. It bonded together so that an adhesive bond layer might overlap.
<Coating liquid for forming the adhesive layer>
Polyfunctional polyol (Takelac A-969V, manufactured by Mitsui Chemicals) 30.0 parts Isocyanate (Takenate A-5, manufactured by Mitsui Chemicals) 10.0 parts Ethyl acetate 60.0 parts

Subsequently, on the surface opposite to the surface on which the adhesive layer of the microvoid film is provided, a primer layer forming coating solution having the following composition is coated with a wire bar so that the dry coating amount is 2.0 g / m ^2. Was applied and dried to form a primer layer.
<Primer layer forming coating solution>
Polyester polyol (Adcoat, manufactured by Toyo Morton Co., Ltd.) 15.0 parts Methyl ethyl ketone / toluene (mass ratio 2: 1) 85.0 parts

On the formed primer layer, a dye receiving layer forming coating solution having the following composition is applied by wire bar coating so that the dry coating amount is 4.0 g / m ² and dried to form a dye receiving layer. As a result, a thermal transfer image receiving sheet was obtained.
<Dye-receiving layer forming coating solution>
Vinyl chloride-vinyl acetate copolymer resin (Solvine C, manufactured by Nissin Chemical Industry Co., Ltd.)
(Vinyl chloride / vinyl acetate = 87/13, number average molecular weight 31,000, glass transition temperature 70 ° C.) 20.0 parts Carboxyl-modified silicone (X-22-3701E, manufactured by Shin-Etsu Chemical Co., Ltd.)
1.0 part Methyl ethyl ketone // toluene (mass ratio 1: 1) 79.0 parts

<Preparation of printed matter>
The thermal transfer image receiving sheet obtained above was used as a transfer target. Black where the dye layer of the thermal transfer sheet consisting of each dye ribbon and the dye receiving surface of the transfer target are placed facing each other and thermal transfer recording is performed from the back side of the thermal transfer sheet using a thermal head, and the printing energy is evenly spaced. 18 gradation images were formed. Further, after the image formation, an overcoat of a ribbon exclusively for Olympus P-400 printer was thermally transferred. The printing conditions were as follows.

Printing conditions Thermal head: F3598 (Toshiba Hokuto Electronics Co., Ltd.)
Heating element average resistance: 5176 (Ω)
Main scanning direction printing density: 300 dpi
Sub-scanning direction printing density: 300 dpi
Printing power: 0.12 (W / dot)
1 line cycle: 2 (msec.)
Pulse duty: 85%
Printing start temperature: 35.5 (° C)

<Evaluation of blackness>
Using a spectrophotometer (GretagMacbeth Spectrolino, manufactured by Gretag) for each location of the 18-gradation black image obtained as described above, the white reference is the absolute value, the D50 light source, and the observation field of view at 2 ° is the density. As a standard, chromaticity values L ^* , a ^* and b ^* were measured (L ^* , a ^* and b ^* are based on the CIE 1976 L ^* a ^* b ^* color system, L ^* is the lightness, a ^{* And} b ^* represent perceptual chromaticity index). The saturation C ^* was calculated from the obtained chromaticity value. The saturation C ^* is a distance from the central axis (achromatic axis) of the color space. In the case of an achromatic color (white, black, gray), C ^* is 0, and the value of C ^* is 0. The closer it is, the neutral black color is meant.

Further, the difference between the maximum value and the minimum value of 18 a ^* and the difference between the maximum value and the minimum value of b ^* measured for each gradation point of the 18 gradation image was calculated. Further, the reflection density was measured using a Macbeth reflection densitometer (RD-918, manufactured by Sakata Inx Co., Ltd.) for the portion printed with the highest energy among the 18 gradation images. The results were as shown in Table 1 below.

<Light resistance evaluation>
A yellow image, a black image, a red image, and a green image were formed in the same manner as described above, and the respective printed materials were xenon weatherweather (Atlas, Ci4000: black panel temperature 45 ° C., filter: inside: CIRA, outside: Irradiation for 48 hours (200 kJ) was carried out with soda lime, 30 ° C., 30% in the testing machine, and ultraviolet light with irradiation control of 420 nm fixed at 1.2 W / m ² , and ΔE ^* ab was calculated. Delta] E ^* ab is, ΔE ^* ab = around before irradiation OD = 1 ((after irradiation ^{L *} - before irradiation ^{L *)} 2 + (after irradiation ^{a *} - before irradiation ^{a *)} 2 + (after irradiation ^{b *} - irradiated Previous b ^* ) ² ) Confirmed by ^1/2 . The side color conditions were as follows.

Colorimetric condition colorimeter : spectrophotometer (GretagMacbeth Spectrolino, Gretag)
Light source: D65
Viewing angle: 2 °
Density measurement filter: ANSI Status A

The obtained light resistance evaluation result (ΔE ^* ab near OD = 1 before irradiation) was as shown in Table 1 below. Since the maximum density of the yellow image of Comparative Example 2 was 0.61, ΔE ^* ab near OD = 1 before irradiation could not be calculated.

Claims (11)

A thermal transfer sheet comprising at least a yellow dye layer, a magenta dye layer, and a cyan dye layer,
Each of the yellow dye layer, the magenta dye layer, and the cyan dye layer is provided with a dye layer comprising a dye pigment and a binder resin on a substrate.
The yellow dye comprises a dye pigment composed of a compound represented by the following formula (YI):

(Where
R ₁ and R ₂ each independently represent a C1-C4 alkyl group,
R ₃ represents a hydrogen atom or a C1-C8 alkyl group which may have a branch,
R ₄ represents a C1-C4 alkyl group. )
The magenta dye is at least selected from the group consisting of a compound represented by the following formula (MI), a compound represented by the following formula (M-II), and a compound represented by the following formula (M-III). Comprising one dye pigment,

(Where
Ring A represents a pyridine ring which may have a substituent,
R ₅ and R ₆ each independently represent a hydrogen atom, an optionally substituted alkyl group, an allyl group, an optionally substituted aryl group or an optionally substituted cycloalkyl group;
R ₇ represents an optionally substituted alkyl group or an optionally substituted aryl group;
R ₈ represents a hydrogen atom, an optionally substituted alkyl group or an optionally substituted aryl group. )

(Where
Ring E represents a pyridine ring which may have a substituent,
R ₉ and R ₁₀ each independently represent a hydrogen atom, an optionally substituted alkyl group, an allyl group, an optionally substituted aryl group or an optionally substituted cycloalkyl group;
R ₁₁ represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, an alkoxy group, an alkoxycarbonyl group, a cyano group or a carbamoyl group,
R ₁₂ represents an optionally substituted alkyl group or an optionally substituted aryl group. )

(Where
R ₁₃ and R ₁₄ each independently represents an amino group or a hydroxy group,
R ₁₅ and R ₁₆ each independently represent a hydrogen atom or an optionally substituted aryloxy group. )
The cyan dye comprises at least one dye pigment selected from the group consisting of a compound represented by the following formula (CI) and a compound represented by the following formula (C-II).

(Where
Ring G represents a benzene ring optionally having a substituent,
R ₁₇ and R ₁₈ each independently represent a hydrogen atom, an optionally substituted alkyl group, an allyl group, an optionally substituted aryl group or an optionally substituted cycloalkyl group;
R ₁₉ represents a hydrogen atom or an optionally substituted alkyl group,
R ₂₀ represents an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aryl group or an optionally substituted aryloxy group,
R ₂₁ represents a hydrogen atom or a halogen atom. )

(In the formula, R ₂₂ and R ₂₃ each independently represent a hydrogen atom, an optionally substituted alkyl group or an optionally substituted aryl group.)
A thermal transfer sheet characterized by that. The thermal transfer sheet according to claim 1, wherein R ₁ and R _{2 in} the formula (YI) are both C2 to C3 alkyl groups. The thermal transfer sheet according to claim 1 or 2, wherein R _{3 in the} formula (YI) is a C2 to C4 alkyl group. The thermal transfer sheet according to any one of claims 1 to 3, wherein R _{4 in the} formula (YI) is an ethyl group.   The thermal transfer sheet according to any one of claims 1 to 4, wherein the yellow dye further comprises a quinophthalone pigment. The thermal transfer sheet according to any one of claims 1 to 5, wherein the dye pigment of the formula (MI) is represented by the following formula (MII).

The dye pigment of the formula (M-III) is represented by the following formula (M-III-I) or (M-III-II), according to any one of claims 1 to 6. Thermal transfer sheet.

The thermal transfer sheet according to any one of claims 1 to 7, wherein the dye pigment of the formula (CI) is represented by the following formula (CII).

The thermal transfer sheet according to any one of claims 1 to 8, wherein the dye pigment of the formula (C-II) is represented by the following formula (C-II-I).

  The thermal transfer sheet according to claim 7, wherein the magenta dye comprises a dye pigment represented by the formula (M-I-I), the formula (M-III-I), and the formula (M-III-II).   The thermal transfer sheet according to claim 9, wherein the cyan dye comprises a dye pigment represented by the formula (C-I-I) and the formula (C-II-I).