JP6458607B2 - Thermal transfer sheet - Google Patents

Description

  The present invention relates to a thermal transfer sheet.

  As a method of forming an image using thermal transfer, a dye-receiving layer is provided on a sublimation type thermal transfer sheet in which a sublimable dye is supported on a base material such as a plastic film and another base material such as paper or plastic film. A sublimation thermal transfer method is known in which a thermal transfer image receiving sheet is superposed on each other to form a full color image. Since this method uses sublimation dyes as color materials, it has excellent reproducibility and gradation of intermediate colors, and can express full-color images exactly as they are on a thermal transfer image-receiving sheet. It is applied to color image formation for computers. The image is of a high quality comparable to a silver salt photograph.

  For example, as disclosed in Patent Document 1, in a sublimation type thermal transfer sheet, a three-color structure in which a yellow dye layer, a magenta dye layer, and a cyan dye layer are provided in this order on a substrate in this order. There is an integrated type. When “black” is reproduced using the three-color integrated thermal transfer sheet, a yellow dye, a magenta dye, and a cyan dye are transferred in an overlapping manner.

  On the other hand, as disclosed in Patent Document 2, for example, a so-called four-color integrated thermal transfer sheet having a black dye layer on a substrate in addition to the three color dye layers has been put into practical use. When “black” is reproduced using the four-color integrated thermal transfer sheet, it is sufficient to transfer the black dye.

JP-A-7-304272 JP-A-7-081251

  However, when “black” is reproduced using the three-color integrated thermal transfer sheet, as described above, the yellow dye, the magenta dye, and the cyan dye are transferred on top of each other. In some cases, reverse transfer may occur to the dye layer for transfer, and the desired “black” may not be accurately reproduced.

  On the other hand, when reproducing “black” using the four-color integrated thermal transfer sheet, the problem does not occur as in the three-color integrated thermal transfer sheet, but in the stage of producing the black dye layer, it is usually fluorescent. Various sublimation dyes are often blended in the image of “black” under the lamp, and the desired “black” may not be reproduced when exposed to a light source other than a fluorescent lamp.

  The present invention is an invention made under such circumstances, and it is easy to reproduce “black” and reproduces the desired “black” even when exposed to a light source other than a fluorescent lamp. It is a main object to provide a thermal transfer sheet that can be used.

  The present invention for solving the above-mentioned problems is a thermal transfer sheet in which a black dye layer is provided on a substrate, and the black dye layer contains at least a sublimable dye represented by the following general formula (1). It is contained, and 1 or 2 or more sublimable dyes selected from the group consisting of sublimable dyes represented by the following general formulas (2) to (5) are contained.

（一般式（１）中の環Ａは、置換または非置換のアリール基を表し、Ｒ¹、Ｒ²はそれぞれ独立に、水素原子、置換又は非置換のアルキル基、置換又は非置換のアリル基、置換又は非置換のアリール基、または、置換又は非置換のシクロアルキル基を表し、Ｒ³は、置換又は非置換のアルキル基、置換又は非置換のアルコキシ基、置換又は非置換のアミノ基、または水素原子を表し、Ｒ⁴は、置換又は非置換のアルキル基、または、置換又は非置換のアリール基を表す。）

(Ring A in General Formula (1) represents a substituted or unsubstituted aryl group, and R ¹ and R ² are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted allyl group. Represents a substituted or unsubstituted aryl group or a substituted or unsubstituted cycloalkyl group, and R ³ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, Or represents a hydrogen atom, and R ⁴ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.

（一般式（２）中のＲ¹及びＲ²はそれぞれ独立に、水素原子、置換又は非置換のアルキル基、置換又は非置換のシクロアルキル基又は置換又は非置換のアラルキル基を、Ｒ³は置換又は非置換のアルキル基、置換又は非置換のアルコキシ基、置換又は非置換のアルキルカルボニルアミノ基、置換又は非置換のアルキルスルホニルアミノ基、置換又は非置換のアルキルアミノカルボニル基、置換又は非置換のアルキルアミノスルホニル基、水素原子又はハロゲン原子を、Ｒ⁴は置換又は非置換のアルキル基、置換又は非置換のアラルキル基、置換又は非置換のアリール基、置換又は非置換のアミノ基、置換又は非置換のシクロアルキル基、シアノ基、ニトロ基又はハロゲン原子を、ｎは１〜４の整数を表わす。）

(R ¹ and R ^{2 in} general formula (2) are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group or a substituted or unsubstituted aralkyl group, and R ³ is Substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted alkylcarbonylamino group, substituted or unsubstituted alkylsulfonylamino group, substituted or unsubstituted alkylaminocarbonyl group, substituted or unsubstituted An alkylaminosulfonyl group, a hydrogen atom or a halogen atom, R ⁴ is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted amino group, substituted or (Unsubstituted cycloalkyl group, cyano group, nitro group or halogen atom, n represents an integer of 1 to 4)

（一般式（３）中のＲ¹〜Ｒ⁴はそれぞれ独立に、置換又は非置換のアルキル基を表す。）

(R ^{1 to} R ⁴ in the general formula (3) each independently represents a substituted or unsubstituted alkyl group.)

（一般式（４）中のＲ¹およびＲ²はそれぞれ独立に、水素原子、置換又は非置換のアルキル基、アリル基、置換又は非置換のアリール基、または置換又は非置換のシクロアルキル基を表し、Ｒ³は、水素原子、炭素数１以上４以下のアルコキシ基、メチル基、またはハロゲン原子を表し、Ｒ⁴は、メチル基、メトキシ基、ホルミルアミノ基、炭素数１以上４以下のアルキルカルボニルアミノ基、炭素数１以上８以下のアルキルスルホニルアミノ基、または炭素数１以上８以下のアルコキシカルボニルアミノ基を表し、Ｒ⁵は、水素原子、ニトロ基、または置換又は非置換のアルキル基を表す。）

(R ¹ and R ² in the general formula (4) are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, an allyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted cycloalkyl group. R ³ represents a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, a methyl group, or a halogen atom, and R ⁴ represents a methyl group, a methoxy group, a formylamino group, or an alkyl having 1 to 4 carbon atoms. Represents a carbonylamino group, an alkylsulfonylamino group having 1 to 8 carbon atoms, or an alkoxycarbonylamino group having 1 to 8 carbon atoms, and R ⁵ represents a hydrogen atom, a nitro group, or a substituted or unsubstituted alkyl group. Represents.)

（一般式（５）中の環Ａは、置換又は非置換のアリール基を表し、Ｒ¹およびＲ²はそれぞれ独立に、水素原子、置換又は非置換のアルキル基、アリル基、置換又は非置換のアリール基、または置換又は非置換のシクロアルキル基を表す。）

(Ring A in the general formula (5) represents a substituted or unsubstituted aryl group, and R ¹ and R ² are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, an allyl group, a substituted or unsubstituted group. Of the aryl group, or a substituted or unsubstituted cycloalkyl group.)

  In the above invention, the black dye layer may further contain one or both of sublimable dyes represented by the following general formula (6) and general formula (7). .

（一般式（６）中のＸおよびＹはそれぞれ独立に、−Ｓ−、−Ｏ−、または−ＳＯ₂−を表し、Ｒ¹およびＲ²はそれぞれ独立に、置換又は非置換のアルキル基、置換又は非置換のシクロアルキル基、置換又は非置換のアリール基または置換又は非置換のアリル基を表す。）

(In formula (6) X and Y are each independently in, -S -, - O-, or -SO ₂ - represent, respectively R ¹ and R ² are independently a substituted or unsubstituted alkyl group, Represents a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted allyl group.)

（一般式（７）中のＸは、−Ｓ−、−Ｏ−、または−ＳＯ₂−を表し、Ｒ¹は、置換又は非置換のアルキル基、置換又は非置換のシクロアルキル基、置換又は非置換のアリール基または置換又は非置換のアリル基を表す。）

(X in the general formula (7) represents —S—, —O—, or —SO ₂ —, and R ¹ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or Represents an unsubstituted aryl group or a substituted or unsubstituted allyl group.)

  According to the thermal transfer sheet of the present invention, “black” can be easily reproduced, and a desired “black” can be reproduced even when exposed to a light source other than a fluorescent lamp.

It is a schematic sectional drawing which shows an example of the thermal transfer sheet of this invention.

  Hereinafter, the thermal transfer sheet of the present invention will be described in detail.

  FIG. 1 is a schematic sectional view showing an example of the thermal transfer sheet of the present invention.

  As shown in FIG. 1, a thermal transfer sheet 10 according to an embodiment of the present invention is provided with a black dye layer 2Bk on a substrate 1, and the black dye layer 2Bk contains a predetermined sublimable dye. It has the feature in being. In the thermal transfer sheet 10 according to the present embodiment shown in FIG. 1, the primer layer 3 is provided between the base material 1 and the black dye layer 2Bk, and the black dye layer 2Bk of the base material 1 is provided. Although the back surface layer 5 is provided on the surface opposite to the provided surface, these layers are arbitrary layers. Hereinafter, each configuration of the thermal transfer sheet 10 according to the present embodiment will be specifically described.

(Base material)
The substrate 1 is not particularly limited as long as it has a certain degree of heat resistance and strength, and a conventionally known material can be appropriately selected and used. As such a substrate 1, for example, a polyethylene terephthalate film, a 1,4-polycyclohexylenedimethylene terephthalate film, a polyethylene naphthalate film, a polyphenylene sulfide having a thickness of about 0.5 μm to 50 μm, preferably about 1 μm to 10 μm. 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. . Furthermore, each of these materials can be used alone, but may be used as a laminate in combination with other materials.

  Moreover, the base material 1 may be subjected to an adhesion treatment on the surface on which the black dye layer 2Bk is formed. By performing the adhesion treatment, adhesion between the base material 1 and the black dye layer 2Bk or an arbitrary layer provided between the base material 1 and the black dye layer 2Bk, for example, the primer layer 3 can be improved.

  Examples of the adhesion treatment include known resin surface modifications such as corona discharge treatment, flame treatment, ozone treatment, ultraviolet treatment, radiation treatment, surface roughening treatment, chemical treatment, plasma treatment, low temperature plasma treatment, primer treatment, and grafting treatment. Quality technology can be applied as it is. Two or more of these treatments can be used in combination. Further, instead of performing the adhesion treatment on the substrate 1, a primer layer 3 (sometimes referred to as an undercoat layer) may be provided between the substrate 1 and the black dye layer 2Bk. Moreover, you may provide the primer layer 3 between the base material 1 and the magenta dye layer to which the adhesion process was performed.

(Black dye layer)
As shown in FIG. 1, a black dye layer 2Bk is provided on the substrate 1, and the black dye layer 2Bk contains a predetermined sublimable dye and a binder resin. Hereinafter, these will be described in detail.

  First, since the black dye layer 2Bk constituting the thermal transfer sheet 10 according to the present embodiment is “black”, three sublimation dyes such as a yellow sublimation dye, a magenta sublimation dye, and a cyan sublimation dye are used. Is assumed to be included. Under this premise, in the present embodiment, at least the sublimable dye represented by the following general formula (1) is contained, and from the sublimable dye represented by the following general formulas (2) to (5). 1 or 2 or more sublimable dyes selected from the group consisting of:

（一般式（１）中の環Ａは、置換または非置換のアリール基を表し、Ｒ¹、Ｒ²はそれぞれ独立に、水素原子、置換又は非置換のアルキル基、置換又は非置換のアリル基、置換又は非置換のアリール基、または、置換又は非置換のシクロアルキル基を表し、Ｒ³は、置換又は非置換のアルキル基、置換又は非置換のアルコキシ基、置換又は非置換のアミノ基、または水素原子を表し、Ｒ⁴は、置換又は非置換のアルキル基、または、置換又は非置換のアリール基を表す。）

(Ring A in General Formula (1) represents a substituted or unsubstituted aryl group, and R ¹ and R ² are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted allyl group. Represents a substituted or unsubstituted aryl group or a substituted or unsubstituted cycloalkyl group, and R ³ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, Or represents a hydrogen atom, and R ⁴ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.

（一般式（２）中のＲ¹及びＲ²はそれぞれ独立に、水素原子、置換又は非置換のアルキル基、置換又は非置換のシクロアルキル基又は置換又は非置換のアラルキル基を、Ｒ³は置換又は非置換のアルキル基、置換又は非置換のアルコキシ基、置換又は非置換のアルキルカルボニルアミノ基、置換又は非置換のアルキルスルホニルアミノ基、置換又は非置換のアルキルアミノカルボニル基、置換又は非置換のアルキルアミノスルホニル基、水素原子又はハロゲン原子を、Ｒ⁴は置換又は非置換のアルキル基、置換又は非置換のアラルキル基、置換又は非置換のアリール基、置換又は非置換のアミノ基、置換又は非置換のシクロアルキル基、シアノ基、ニトロ基又はハロゲン原子を、ｎは１〜４の整数を表わす。）

(R ¹ and R ^{2 in} general formula (2) are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group or a substituted or unsubstituted aralkyl group, and R ³ is Substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted alkylcarbonylamino group, substituted or unsubstituted alkylsulfonylamino group, substituted or unsubstituted alkylaminocarbonyl group, substituted or unsubstituted An alkylaminosulfonyl group, a hydrogen atom or a halogen atom, R ⁴ is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted amino group, substituted or (Unsubstituted cycloalkyl group, cyano group, nitro group or halogen atom, n represents an integer of 1 to 4)

（一般式（３）中のＲ¹〜Ｒ⁴はそれぞれ独立に、置換又は非置換のアルキル基を表す。）

(R ^{1 to} R ⁴ in the general formula (3) each independently represents a substituted or unsubstituted alkyl group.)

（一般式（４）中のＲ¹およびＲ²はそれぞれ独立に、水素原子、置換又は非置換のアルキル基、アリル基、置換又は非置換のアリール基、または置換又は非置換のシクロアルキル基を表し、Ｒ³は、水素原子、炭素数１以上４以下のアルコキシ基、メチル基、またはハロゲン原子を表し、Ｒ⁴は、メチル基、メトキシ基、ホルミルアミノ基、炭素数１以上４以下のアルキルカルボニルアミノ基、炭素数１以上８以下のアルキルスルホニルアミノ基、または炭素数１以上８以下のアルコキシカルボニルアミノ基を表し、Ｒ⁵は、水素原子、ニトロ基、または置換又は非置換のアルキル基を表す。）

(R ¹ and R ² in the general formula (4) are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, an allyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted cycloalkyl group. R ³ represents a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, a methyl group, or a halogen atom, and R ⁴ represents a methyl group, a methoxy group, a formylamino group, or an alkyl having 1 to 4 carbon atoms. Represents a carbonylamino group, an alkylsulfonylamino group having 1 to 8 carbon atoms, or an alkoxycarbonylamino group having 1 to 8 carbon atoms, and R ⁵ represents a hydrogen atom, a nitro group, or a substituted or unsubstituted alkyl group. Represents.)

（一般式（５）中の環Ａは、置換又は非置換のアリール基を表し、Ｒ¹およびＲ²はそれぞれ独立に、水素原子、置換又は非置換のアルキル基、アリル基、置換又は非置換のアリール基、または置換又は非置換のシクロアルキル基を表す。）

(Ring A in the general formula (5) represents a substituted or unsubstituted aryl group, and R ¹ and R ² are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, an allyl group, a substituted or unsubstituted group. Of the aryl group, or a substituted or unsubstituted cycloalkyl group.)

Yellow Sublimation Dye The sublimation dye represented by the general formula (1) is classified as a yellow sublimation dye, and is necessarily contained in the black dye layer 2Bk according to the present embodiment. This sublimation dye is a sublimation dye having a pyrazolone methine skeleton, and has higher transfer sensitivity than a commonly used yellow sublimation dye. be able to. In addition, this sublimable dye absorbs long wavelength light well, so that the valley of absorption between yellow and magenta can be reduced, and the black reproducibility is excellent even under various light sources other than fluorescent lamps. Yes.

In the sublimable dye represented by the general formula (1), “ring A” in the general formula (1) is an unsubstituted aryl group, and “R ¹ ” and “R ² ” are a methyl group and an ethyl group, respectively. , Or a propyl group, “R ³ ” is an alkyloxy group, an aryloxy group, or an amino group, and “R ⁴ ” is an alkyl group, an aryl group, or hydrogen. It is preferable.

  Moreover, the following general formula (1-1) can be mentioned as a specific example of the sublimable dye shown by the said General formula (1).

  The black dye layer 2Bk in the thermal transfer sheet 10 according to the present embodiment may include a sublimation dye other than the sublimation dye represented by the general formula (1) as a yellow sublimation dye. For example, known yellow sublimation dyes such as diarylmethane dyes; triarylmethane dyes; thiazole dyes; merocyanine dyes; methine dyes such as pyrazolone methine; indoaniline dyes; acetophenone azomethine, pyrazoloazomethine, imidazo Azomethine dyes represented by ruazomethine, imidazoazomethine and pyridoneazomethine; xanthene dyes; oxazine dyes; cyanostyrene dyes represented by dicyanostyrene and tricyanostyrene; thiazine dyes; azine dyes; acridine dyes Benzene azo dyes; azo dyes other than the above general formula (1) such as pyridone azo, thiophenazo, isothiazole azo, pyrrole azo, pyral azo, imidazole azo, thiadiazole azo, triazole azo, dizazo, etc. Fee; spiropyran dyes; Indian Linus Piropi run dyes; fluoran dyes; rhodamine lactam dyes; naphthoquinone dyes; anthraquinone dyes; quinophthalone dyes, etc. may be used.

  In addition, since it can be obtained as a commercial product, Disperse Yellow 201 (Macrolex Yellow 6G, LANXESS) represented by the following general formula (8), Solvent Yellow 93 (for example, Plas Yellow 8000 (trade name), Arimoto Chemical dyes, etc.) and dyes of the following general formula (9) are particularly preferred.

  The ratio of the sublimable dye represented by the general formula (1) to the total solid content of the yellow sublimable dye is the kind of sublimable dye used in combination with the sublimable dye represented by the general formula (1). For example, 5 to 40% by mass is preferable, and 10 to 35% by mass is particularly preferable.

-Magenta sublimable dye The sublimable dyes represented by the general formulas (2) to (4) are classified as magenta sublimable dyes, and are selectively contained in the black dye layer 2Bk according to the present embodiment. Is. More specifically, any one or two or more sublimable dyes represented by the general formulas (2) to (4) may be contained. On the other hand, a cyan sublimable dye described later. In the case where the sublimable dye represented by the general formula (5) classified as follows is contained, none of the sublimable dyes represented by the general formulas (2) to (4) may be contained.

  The sublimation dye represented by the general formula (2) is a sublimation dye having a pyrazolotriazole azomethine skeleton, and has a higher transfer sensitivity than a commonly used magenta sublimation dye, and the concentration is the same even when the same amount is added. Because it is easy to put out, black can be reproduced more beautifully. The sublimation dye represented by the general formula (3) absorbs light of short wavelengths well, so that the valley of absorption between yellow and magenta can be reduced, and it can be combined with other magenta sublimation dyes. Black can be reproduced even under various light sources other than fluorescent lamps. The sublimation dye represented by the above general formula (4) is cheaper than the commonly used magenta sublimation dye, but has high transfer sensitivity, and it is easy to obtain a concentration even with the same amount of addition, so black is reproduced more beautifully. can do. The sublimable dye represented by the general formula (2) and the sublimable dye represented by the general formula (3) are combined, or the sublimable dye represented by the general formula (3) and the general formula (4) By combining with the sublimable dyes shown, it is easy to obtain a density and easily reproduce the black hue.

Sublimable dye represented by the general formula (2) has the general formula (2) "R ^1" and "R ^2" in is either a methyl group, an ethyl group, or propyl group respectively, "R ³ “Is an unsubstituted alkyl group,“ R ⁴ ”is a substituted aralkyl group, a substituted aryl group, or a halogen atom, and“ n ”is preferably 1.

  Moreover, the following general formula (2-1) etc. can be mentioned as a specific example of the sublimable dye shown by the said General formula (2).

In the sublimation dye represented by the general formula (3), “R ¹ ”, “R ² ”, “R ³ ”, and “R ⁴ ” in the general formula (3) are each a methyl group, an ethyl group, or It is preferably any one of propyl groups.

  Moreover, the following general formula (3-1) etc. can be mentioned as a specific example of the sublimable dye shown by the said General formula (3).

Sublimable dye represented by the general formula (4) of the general formula (4) "R ^1" and "R ^2" in is either a methyl group, an ethyl group, or propyl group respectively, "R ³ “Is a hydrogen atom,“ R ⁴ ”is an alkylsulfonylamino group having 1 to 3 carbon atoms, and“ R ⁵ ”is preferably a methyl group, an ethyl group, or a propyl group.

  Moreover, the following general formula (4-1) etc. can be mentioned as a specific example of the sublimable dye shown by the said General formula (4).

  For the black dye layer 2Bk in the thermal transfer sheet 10 according to the present embodiment, as the magenta sublimation dye, either a sublimation dye represented by the following general formula (6) or a sublimation dye represented by the above general formula (7) One or both are preferably included.

（一般式（６）中のＸおよびＹはそれぞれ独立に、−Ｓ−、−Ｏ−、または−ＳＯ₂−を表し、Ｒ¹およびＲ²はそれぞれ独立に、置換又は非置換のアルキル基、置換又は非置換のシクロアルキル基、置換又は非置換のアリール基または置換又は非置換のアリル基を表す。）

(In formula (6) X and Y are each independently in, -S -, - O-, or -SO ₂ - represent, respectively R ¹ and R ² are independently a substituted or unsubstituted alkyl group, Represents a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted allyl group.)

（一般式（７）中のＸは、−Ｓ−、−Ｏ−、または−ＳＯ₂−を表し、Ｒ¹は、置換又は非置換のアルキル基、置換又は非置換のシクロアルキル基、置換又は非置換のアリール基または置換又は非置換のアリル基を表す。）

(X in the general formula (7) represents —S—, —O—, or —SO ₂ —, and R ¹ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or Represents an unsubstituted aryl group or a substituted or unsubstituted allyl group.)

  The sublimable dye represented by the general formula (6) and the sublimable dye represented by the general formula (7) are both sublimable dyes having an anthraquinone skeleton. The sublimable dye represented by the general formula (6) absorbs long wavelength light well, so that the valley of absorption between magenta and cyan can be reduced, and fluorescence can be obtained by combining with other magenta sublimable dyes. Black can be reproduced even under various light sources other than lamps. The sublimation dye represented by the general formula (7) is excellent in light resistance as compared with a commonly used magenta sublimation dye. Further, it is easy to obtain a concentration by combining the sublimable dye represented by the general formula (2) or the sublimable dye represented by the general formula (4) with the sublimable dye represented by the general formula (6). The black hue is easy to reproduce.

In the sublimation dye represented by the general formula (6), “X” and “Y” in the general formula (6) are —O—, and “R ¹ ” and “R ² ” are each an unsubstituted aryl. It is preferably a group.

  Moreover, the following general formula (6-1) etc. can be mentioned as a specific example of the sublimable dye shown by the said General formula (6).

In the sublimable dye represented by the general formula (7), “X” in the general formula (7) is preferably —O—, and “R ¹ ” is preferably an unsubstituted aryl group.

  Moreover, the following general formula (7-1) etc. can be mentioned as a specific example of the sublimable dye shown by the said General formula (7).

  The black dye layer 2Bk in the thermal transfer sheet 10 according to the present embodiment may contain a sublimation dye other than the sublimation dyes represented by the general formulas (2) to (7) as a magenta sublimation dye. . For example, various nonionic dyes such as azo dyes, anthraquinone dyes, nitro dyes, styryl dyes, naphthoquinone dyes, quinophthalone dyes, azomethine dyes, coumarin dyes, condensed polycyclic compound dyes, etc. In particular, it is preferable to use a sublimable dye represented by the following general formulas (10) to (15) in combination.

  The sublimable dyes represented by the general formulas (10) and (11) have a hue comparable to that of the general formula (7), and can easily produce a high concentration. Further, the sublimable dyes represented by the general formulas (12) and (13) have a hue close to the above general formula (2), and can produce a very high concentration. It is also excellent in light resistance.

  The ratio of the sublimable dye represented by the general formulas (2) to (4) to the total solid content of the magenta sublimable dye is the same as the sublimable dye represented by the general formulas (2) to (4). Although it varies depending on the type of sublimable dye used in combination, it is preferably, for example, 5 to 55% by mass, particularly preferably 10 to 50% by mass. Similarly, the ratio of the sublimable dyes represented by the general formulas (6) and (7) to the total solid content of the magenta sublimable dye is preferably, for example, 5 to 55% by mass, and 10 to 50% by mass. It is particularly preferred that

Cyan sublimation dye The sublimation dye represented by the general formula (5) is classified as a cyan sublimation dye, and is selectively contained in the black dye layer 2Bk according to the present embodiment. . More specifically, the sublimable dye represented by the general formula (5) may be contained, while the general formulas (2) to (4) classified as the above-described magenta sublimable dye. When any of the sublimable dyes shown is contained, the sublimable dye represented by the general formula (5) may not be contained. This sublimation dye is a sublimation dye having a cyanomethylene skeleton, has higher transfer sensitivity than the commonly used cyan sublimation dye, and can easily produce a concentration even with the same amount of addition, so that black is reproduced more beautifully. be able to. In addition, because it absorbs light of short wavelengths well, it can reduce the valley of absorption between magenta and cyan, and when combined with other cyan sublimation dyes, black can be obtained under various light sources other than fluorescent lamps. Can be reproduced.

In the sublimable dye represented by the general formula (5), “Ring A” in the general formula (5) is an unsubstituted aryl group, and “R ¹ ” and “R ² ” each have 2 to 8 carbon atoms. The alkyl group is preferably

  Moreover, the following general formula (5-1) etc. can be mentioned as a specific example of the sublimable dye shown by the said General formula (5).

  The black dye layer 2Bk in the thermal transfer sheet 10 according to the present embodiment may contain a sublimation dye other than the sublimation dye represented by the general formula (5) as a cyan sublimation dye. Specific examples include sublimable dyes represented by the following general formulas (16) to (21).

  The ratio of the sublimable dye represented by the general formula (5) to the total solid content of the cyan sublimable dye is the kind of sublimable dye used in combination with the sublimable dye represented by the general formula (5). For example, it is preferably 35 to 70% by mass, and particularly preferably 40 to 65% by mass.

  Here, the ratio of each of the yellow sublimation dye, the magenta sublimation dye, and the cyan sublimation dye to the total solid content of the sublimation dye contained in the black dye layer 2Bk in the thermal transfer sheet 10 according to the present embodiment is as follows. Depending on the specific combination of the sublimation dyes used as the sublimation dye, for example, yellow sublimation dye: magenta sublimation dye: cyan sublimation dye = 5-35: 5-55: 30-85 is preferable, 10-30: 10-50: 35-80 are especially preferable.

-Binder resin The black dye layer 2Bk in the thermal transfer sheet 10 according to the present embodiment contains a binder resin for supporting various sublimation dyes as described above. The binder resin is not particularly limited, and a binder resin having a certain degree of heat resistance and having a moderate affinity with a sublimation dye can be used. Examples of such a binder resin include cellulose resins such as nitrocellulose, ethylcellulose, hydroxyethylcellulose, ethylhydroxycellulose, hydroxypropylcellulose, methylcellulose, cellulose acetate, and butyrate; polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl Examples thereof include vinyl resins such as acetoacetal and polyvinylpyrrolidone; acrylic resins such as poly (meth) acrylate and poly (meth) acrylamide; polyurethane resins; polyamide resins; polyester resins;

Among the other binder resins exemplified above, the polyvinyl butyral resin and the polyvinyl acetal resin can improve the adhesion with the primer layer 3 that is optionally provided between the substrate 1 and the black dye layer 2Bk. This is preferable.

  There is no particular limitation on the content of the binder resin, but when the content of the binder resin is less than 20% by mass relative to the total solid content of the black dye layer 2Bk, the black dye layer 2Bk can hold the sublimation dye sufficiently. It cannot be done, and the preservability tends to decrease. Therefore, the binder resin is preferably contained in an amount of 20% by mass or more based on the total solid content of the black dye layer 2Bk. There is no restriction | limiting in particular about the upper limit of content of binder resin, According to content of a sublimation dye and arbitrary additives, it can set suitably.

  Further, the concentration can be further improved by increasing the mass ratio (D / B ratio (sublimation dye / binder resin)) (hereinafter referred to as D / B ratio) between the sublimation dye and the binder resin. it can. Specifically, by setting the D / B ratio to 1.5 or more, a high black density can be imparted to a printed matter obtained using the thermal transfer sheet 10 according to the present embodiment. The mass of the sublimable dye is the total mass of all the sublimable dyes contained in the black dye layer 2Bk, and the mass of the binder resin is all the binder resins contained in the black dye layer 2Bk. Means the total mass of

  The upper limit value of the D / B ratio is not particularly limited, but when the D / B ratio exceeds 3.5, the dye amount of the sublimation dye with respect to the binder resin is too large, and the binder resin has a sublimation dye. In some cases, the storage stability cannot be maintained and the storage stability is lowered. Therefore, considering this point, the D / B ratio is preferably in the range of 1.5 to 3.5, and more preferably in the range of 1.7 to 3.0.

Other components The black dye layer 2Bk may contain additives such as inorganic fine particles and organic fine particles. Examples of the inorganic fine particles include carbon black, aluminum, and molybdenum disulfide. Examples of the organic fine particles include polyethylene wax and silicone resin fine particles.

  Moreover, the black dye layer 2Bk may contain a release agent. Examples of the mold release agent include modified or unmodified silicone oil (including those referred to as silicone resins), phosphate esters, and fatty acid esters.

-Formation method of black dye layer There is no limitation in particular about the formation method of black dye layer 2Bk, or a binder resin, a sublimation dye, the additive added as needed, a mold release agent are melt | dissolved in a suitable solvent, or Disperse to prepare a dye layer coating liquid, and apply this black dye layer coating liquid onto the dye primer layer 3 described later by a conventionally known coating means such as a gravure coater, roll coater, wire bar or the like. It can be formed by working and drying. The thickness of the black dye layer 2Bk is generally about 0.2 μm to 2.0 μm.

(Primer layer)
As shown in FIG. 1, in the thermal transfer sheet 10 according to the present embodiment, a primer layer 3 is provided between the substrate 1 and the black dye layer 2Bk. Although the primer layer 3 is an arbitrary layer, the adhesion between the base material 1 and the black dye layer 2Bk can be improved by providing this.

  As the resin constituting the primer layer 3, polyester resin, polyvinyl pyrrolidone resin, polyvinyl alcohol resin, hydroxyethyl cellulose, polyacrylate resin, polyvinyl acetate resin, polyurethane resin, styrene acrylate resin, polyacrylamide resin Examples thereof include resins, polyamide resins, polyether resins, polystyrene resins, polyethylene resins, polypropylene resins, polyvinyl chloride resins, polyvinyl acetal resins such as polyvinyl acetoacetal and polyvinyl butyral, and the like.

  The primer layer 3 may contain inorganic fine particles. This not only prevents abnormal transfer of the black dye layer 2Bk to the thermal transfer image receiving sheet during thermal transfer, but also prevents dye transfer from the black dye layer 2Bk to the primer layer 3 during printing, so that the receiving layer side of the thermal transfer image receiving sheet The dye can be effectively diffused into the ink and the print density can be increased.

  The inorganic fine particles contained in the primer layer 3 are not particularly limited, and examples thereof include fine particles of alumina, silica, carbon black, molybdenum disulfide, etc., and these are inorganic materials derived from colloidal inorganic fine particles. Fine particles may be used. Colloidal inorganic fine particles include silica sol, colloidal silica, alumina or alumina hydrate (colloidal alumina, cationic aluminum oxide or hydrate, pseudoboehmite, etc.), aluminum silicate, magnesium silicate, magnesium carbonate, magnesium oxide And titanium oxide. Such colloidal inorganic fine particles may be processed in an acidic type in order to be easily dispersed in a sol form in a solvent or dispersion medium, or may be those in which the charge of fine particles is converted to a cation. However, it may be surface-treated.

  The shape of the inorganic fine particles contained in the primer layer 3 is not particularly limited, and may be any shape such as a spherical shape, a needle shape, a plate shape, a feather shape, and an amorphous shape. The particle size of the inorganic fine particles is not particularly limited, but when the primer 3 mainly contains inorganic fine particles having a primary particle size exceeding 10 μm, the transparency of the primer layer 3 tends to decrease. . Considering this point, it is preferable that the primer layer 3 mainly contains inorganic fine particles having a primary particle size of 10 μm or less. “Mainly” means 50% by mass or more based on the total mass of the inorganic fine particles contained in the primer layer 3. Although there is no limitation in particular about a lower limit, it is about 0.1 micrometer with the magnitude | size of a primary particle.

Primer layer 3 is a gravure coating method, a roll coating method, a screen printing method, a reverse roll coating method using a gravure plate, in which a resin or inorganic fine particles exemplified above are dissolved or dispersed in an appropriate solvent. It can be formed by coating and drying by a conventionally known forming means such as. The coating amount of the primer layer coating solution is preferably about 0.02 to 1.0 g / m ² .

  Various functional layers may be provided together with or in place of the primer layer 3. Examples of the various functional layers include an antistatic layer.

(Back layer)
As shown in FIG. 1, the back surface layer 5 is provided on the surface of the substrate 1 opposite to the surface on which the black dye layer 2Bk is provided. The back layer 5 is also an arbitrary layer, similar to the primer layer 3, but by providing this, the heat resistance, the running performance of the thermal head during printing, and the like can be improved.

  The back layer 5 can be formed by appropriately selecting a conventionally known thermoplastic resin or the like. As such a thermoplastic resin, for example, polyester resins, polyacrylate resins, polyvinyl acetate resins, styrene acrylate resins, polyurethane resins, polyethylene resins, polypropylene resins, and other polyolefin resins, Polystyrene resin, polyvinyl chloride resin, polyether resin, polyamide resin, polyimide resin, polyamideimide resin, polycarbonate resin, polyacrylamide resin, polyvinyl chloride resin, polyvinyl butyral resin, polyvinyl acetoacetal resin, etc. Examples thereof include thermoplastic resins such as polyvinyl acetal resin, and silicone modified products thereof.

  Moreover, you may add a hardening | curing agent to above-described resin. As the polyisocyanate resin that functions as a curing agent, conventionally known ones can be used without any particular limitation. Among them, it is desirable to use an adduct of an aromatic isocyanate. As the aromatic polyisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, or a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, Examples include p-phenylene diisocyanate, trans-cyclohexane-1,4-diisocyanate, xylylene diisocyanate, triphenylmethane triisocyanate, and tris (isocyanatophenyl) thiophosphate, particularly 2,4-toluene diisocyanate and 2,6-toluene diisocyanate. Or, a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate is preferable. Such a polyisocyanate resin crosslinks the above-mentioned hydroxyl group-containing thermoplastic resin using the hydroxyl group, thereby improving the coating strength and heat resistance of the back layer.

  In addition to the above thermoplastic resin, the back layer 5 has a wax, a higher fatty acid amide, a phosphoric ester compound, a metal soap, a silicone oil, a surfactant and other release agents for the purpose of improving slip properties, fluorine It is preferable that various additives such as organic powders such as resin, inorganic particles such as silica, clay, talc, calcium carbonate and the like are contained, and it is particularly preferable that at least one kind of phosphate ester or metal soap is contained. preferable.

The back layer 5 is, for example, a surface on the opposite side of the black dye layer 2Bk of the base material 1 with a coating liquid in which the thermoplastic resin and various additives added as necessary are dispersed or dissolved in an appropriate solvent. Further, it can be formed by applying and drying by a known means such as a gravure printing method, a screen printing method, a reverse roll coating printing method using a gravure plate. The coating amount of the back layer 5, from the viewpoint of improvement of such as heat resistance, it is preferable that drying after coating weight of 3 g / m ² or less, and more preferably to 0.1-2 g / m ² .

  Hereinafter, the present invention will be described with reference to examples and comparative examples. “Part” in the text is based on mass unless otherwise specified.

Example 1
A polyethylene terephthalate film having a thickness of 5 μm was used as a substrate, and a back layer coating solution having the following composition was applied thereon so as to be 1.0 g / m ² when dried to form a back layer. Next, a primer layer coating solution having the following composition was applied to the surface of the substrate opposite to the side on which the back layer was provided, so that the primer layer was 0.10 g / m ² when dried to form a primer layer. Next, the black dye layer coating liquid 1 having the following composition was applied on the primer layer so as to be 0.35 g / m ² when dried, and dried at 80 ° C. for 2 minutes to form a black dye layer. 1 thermal transfer sheet was obtained.

<Back layer coating liquid>
・ Polyvinyl acetal resin (hydroxyl value 12% by mass) 36 parts (S-REC KS-1 Sekisui Chemical Co., Ltd.)
・ Polyisocyanate (NCO = 17.3 mass%) 25 parts (Bernock D750 Dainippon Ink & Chemicals, Inc.)
・ Particulate silicone resin (particle size: 4μm, polygonal shape) 1 part (Tospearl 240 Momentive Performance Materials Japan GK)
-10 parts of zinc stearyl phosphate (LBT1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.)
・ 10 parts of zinc stearate (SZ-PF manufactured by Sakai Chemical Industry Co., Ltd.)
・ 3 parts of polyethylene wax
・ Ethoxylated alcohol-modified wax 7 parts (Unitox 750, manufactured by Toyo Adre Co., Ltd.)
・ Methyl ethyl ketone 200 parts ・ Toluene 100 parts

<Primer layer coating solution>
・ 9 parts of urethane resin (solid content 26%) (Superflex 650 Daiichi Kogyo Seiyaku Co., Ltd.)
・ Alumina sol (solid content 10%) 3.2 parts (alumina sol 200 Nissan Chemical Industries, Ltd.)
・ Water 62 parts ・ IPA (isopropyl alcohol) 75 parts

<Black dye layer coating solution 1 (D / B ratio = 1.8)>
・ 1.2 parts of a compound represented by the above general formula (1-1) as a yellow sublimable dye 1.4 parts of a compound represented by the above general formula (2-1) as a magenta sublimable dye ・ as a cyan sublimable dye Compound represented by the above general formula (20) 4.6 parts, polyvinyl acetoacetal resin 4.0 parts (ESREC KS-5 manufactured by Sekisui Chemical Co., Ltd.)
・ Polyolefin wax 0.2 parts ・ Neoethanol 4.2 parts ・ Toluene 42.1 parts ・ Methyl ethyl ketone 42.1 parts

(Example 2)
In place of the black dye layer coating liquid 1 used in Example 1, the same conditions as in Example 1 were used except that the black dye layer coating liquid 2 having the following composition was used. A thermal transfer sheet was obtained.

(Example 2)
<Black dye layer coating liquid 2 (D / B ratio = 1.8)>
・ 0.6 parts of a compound represented by the above general formula (1-1) as a yellow sublimation dye ・ 0.6 parts of a compound represented by the above general formula (8) as a yellow sublimation dye ・ the above general as a magenta sublimation dye Compound represented by the formula (2-1) 1.4 parts. Compound represented by the above general formula (20) as a cyan sublimable dye 4.6 parts. Polyvinyl acetoacetal resin 4.0 parts (ESREC KS-5 Sekisui Chemical Co., Ltd.) Manufactured by Kogyo Co., Ltd.)
・ Polyolefin wax 0.2 parts ・ Neoethanol 4.2 parts ・ Toluene 42.1 parts ・ Methyl ethyl ketone 42.1 parts

(Example 3)
In place of the black dye layer coating solution 1 used in Example 1, the same procedure as in Example 1 was applied except that a black dye layer coating solution 3 having the following composition was used. A thermal transfer sheet was obtained.

<Black dye layer coating solution 3 (D / B ratio = 2.1)>
-0.7 part of a compound represented by the above general formula (1-1) as a yellow sublimable dye-0.7 part of a compound represented by the above general formula (8) as a yellow sublimable dye-General above as a magenta sublimable dye Compound represented by formula (3-1) 1.8 parts Compound shown as general formula (20) as cyan sublimation dye 5.2 parts Polyvinyl acetoacetal resin 4.0 parts (ESREC KS-5 Sekisui Chemical Manufactured by Kogyo Co., Ltd.)
・ Polyolefin wax 0.2 parts ・ Neoethanol 4.2 parts ・ Toluene 42.7 parts ・ Methyl ethyl ketone 42.7 parts

(Example 4)
Instead of the black dye layer coating solution 1 used in Example 1 above, the same procedure as in Example 1 was applied except that a black dye layer coating solution 4 having the following composition was used. A thermal transfer sheet was obtained.

<Black Dye Layer Coating Liquid 4 (D / B Ratio = 2.1)>
-0.7 part of a compound represented by the above general formula (1-1) as a yellow sublimable dye-0.7 part of a compound represented by the above general formula (8) as a yellow sublimable dye-General above as a magenta sublimable dye Compound represented by formula (2-1) 0.8 part. Compound represented by the above general formula (3-1) as a magenta sublimable dye 0.8 part. Represented by the above general formula (20) as a cyan sublimable dye. Compound 5.4 parts, polyvinyl acetoacetal resin 4.0 parts (ESREC KS-5 manufactured by Sekisui Chemical Co., Ltd.)
・ Polyolefin wax 0.2 parts ・ Neoethanol 4.2 parts ・ Toluene 42.7 parts ・ Methyl ethyl ketone 42.7 parts

(Example 5)
In place of the black dye layer coating liquid 1 used in Example 1, the same conditions as in Example 1 were used except that a black dye layer coating liquid 5 having the following composition was used. A thermal transfer sheet was obtained.

<Black dye layer coating solution 5 (D / B ratio = 2.1)>
-0.7 part of a compound represented by the above general formula (1-1) as a yellow sublimable dye-0.7 part of a compound represented by the above general formula (8) as a yellow sublimable dye-General above as a magenta sublimable dye Compound represented by formula (2-1): 0.9 part. Compound represented by the above general formula (6-1) as a magenta sublimable dye: 0.9 part: represented by the above general formula (20) as a cyan sublimable dye. Compound 5.2 parts ・ Polyvinylacetoacetal resin 4.0 parts (ESREC KS-5 Sekisui Chemical Co., Ltd.)
・ Polyolefin wax 0.2 parts ・ Neoethanol 4.2 parts ・ Toluene 42.7 parts ・ Methyl ethyl ketone 42.7 parts

(Example 6)
Instead of the black dye layer coating solution 1 used in Example 1 above, the same conditions as in Example 1 except that the black dye layer coating solution 6 having the following composition was used. A thermal transfer sheet was obtained.

<Black dye layer coating liquid 6 (D / B ratio = 2.1)>
-0.7 part of a compound represented by the above general formula (1-1) as a yellow sublimable dye-0.7 part of a compound represented by the above general formula (8) as a yellow sublimable dye-General above as a magenta sublimable dye Compound represented by formula (3-1) 1.8 parts Compound shown as general formula (20) as cyan sublimation dye 5.2 parts Polyvinyl acetoacetal resin 4.0 parts (ESREC KS-5 Sekisui Chemical Manufactured by Kogyo Co., Ltd.)
・ Polyolefin wax 0.2 parts ・ Neoethanol 4.2 parts ・ Toluene 42.7 parts ・ Methyl ethyl ketone 42.7 parts

(Example 7)
In place of the black dye layer coating solution 1 used in Example 1, the same conditions as in Example 1 except that the black dye layer coating solution 7 having the following composition was used. A thermal transfer sheet was obtained.

<Black dye layer coating solution 7 (D / B ratio = 1.8)>
-0.8 part of a compound represented by the above general formula (1-1) as a yellow sublimation dye-0.8 part of a compound represented by the above general formula (8) as a yellow sublimation dye-The above general as a magenta sublimation dye Compound represented by formula (3-1) 1.0 part. Compound represented by the above general formula (6-1) as a magenta sublimable dye 1.0 part. General formula (5-1) as a cyan sublimable dye. 3.6 parts of a compound shown in the following: 4.0 parts of polyvinyl acetoacetal resin (SREC KS-5, manufactured by Sekisui Chemical Co., Ltd.)
・ Polyolefin wax 0.2 parts ・ Neoethanol 4.2 parts ・ Toluene 42.1 parts ・ Methyl ethyl ketone 42.1 parts

(Example 8)
In place of the black dye layer coating liquid 1 used in Example 1, the same conditions as in Example 1 except that the black dye layer coating liquid 8 having the following composition was used. A thermal transfer sheet was obtained.

<Black dye layer coating solution 8 (D / B ratio = 1.8)>
・ 0.6 parts of a compound represented by the above general formula (1-1) as a yellow sublimation dye ・ 0.6 parts of a compound represented by the above general formula (8) as a yellow sublimation dye ・ the above general as a magenta sublimation dye Compound represented by formula (2-1) 0.7 part. Compound represented by general formula (4-1) as magenta sublimable dye. 0.7 part. Compound represented by general formula (5-1) as cyan sublimable dye. 1.0 parts of a compound shown in the above formula 3.6 parts of the compound represented by the above general formula (20) as a cyan sublimation dye 4.0 parts of a polyvinyl acetoacetal resin (manufactured by ESREC KS-5 Sekisui Chemical Co., Ltd.)
・ Polyolefin wax 0.2 parts ・ Neoethanol 4.2 parts ・ Toluene 42.1 parts ・ Methyl ethyl ketone 42.1 parts

Example 9
In place of the black dye layer coating liquid 1 used in Example 1, the same procedure as in Example 1 was applied except that a black dye layer coating liquid 9 having the following composition was used. A thermal transfer sheet was obtained.

<Black dye layer coating solution 9 (D / B ratio = 2.8)>
-0.9 part of a compound represented by the above general formula (1-1) as a yellow sublimation dye-0.9 part of a compound represented by the above general formula (8) as a yellow sublimation dye-The above general as a magenta sublimation dye Compound represented by formula (2-1) 1.2 parts. Compound represented by the above general formula (4-1) as a magenta sublimable dye 1.2 parts. General formula (5-1) as a cyan sublimable dye. 1.5 parts of a compound represented by the above general formula (20) as a cyan sublimation dye 5.4 parts 4.0 parts of a nitrocellulose resin (DHM10-25 manufactured by Inabata Sangyo Co., Ltd.)
・ Polyolefin wax 0.3 part ・ Neoethanol 4.4 part ・ Toluene 44.1 part ・ Methyl ethyl ketone 44.1 part

(Example 10)
In place of the black dye layer coating solution 1 used in Example 1, the same procedure as in Example 10 was applied except that a black dye layer coating solution 10 having the following composition was used. A thermal transfer sheet was obtained.

<Black dye layer coating solution 10 (D / B ratio = 2.1)>
As a yellow sublimation dye 1.4 parts of the compound represented by the above general formula (1-1) As a magenta sublimation dye 1.8 parts of the compound represented by the above general formula (4-1) As a cyan sublimation dye Compound represented by the above general formula (20) 5.2 parts, polyvinyl acetoacetal resin 4.0 parts (ESREC KS-5 manufactured by Sekisui Chemical Co., Ltd.)
・ Polyolefin wax 0.2 parts ・ Neoethanol 4.2 parts ・ Toluene 42.7 parts ・ Methyl ethyl ketone 42.7 parts

(Example 11)
In place of the black dye layer coating solution 1 used in Example 1 above, the black dye layer coating solution 11 having the following composition was used except that the same conditions as in Example 1 were used. A thermal transfer sheet was obtained.

<Black Dye Layer Coating Solution 11 (D / B Ratio = 2.1)>
As a yellow sublimable dye, 1.6 parts of the compound represented by the above general formula (1-1) As a magenta sublimable dye, a compound represented by the above general formula (7-1) 3.2 parts As a cyan sublimable dye Compound represented by the above general formula (5-1) 3.6 parts, polyvinyl acetoacetal resin 4.0 parts (ESREC KS-5 manufactured by Sekisui Chemical Co., Ltd.)
・ Polyolefin wax 0.2 parts ・ Neoethanol 4.2 parts ・ Toluene 42.7 parts ・ Methyl ethyl ketone 42.7 parts

(Example 12)
In place of the black dye layer coating liquid 1 used in Example 1, the same conditions as in Example 1 except that a black dye layer coating liquid 12 having the following composition was used. A thermal transfer sheet was obtained.

<Black Dye Layer Coating Liquid Example 12 (D / B Ratio = 1.8)>
・ 1.4 parts of a compound represented by the above general formula (1-1) as a yellow sublimable dye ・ 1.2 parts of a compound represented by the above general formula (3-1) as a magenta sublimable dye ・ as a magenta sublimable dye Compound represented by the above general formula (7-1) 1.2 parts. Compound represented by the above general formula (5-1) as a cyan sublimation dye 3.4 parts. Polyvinyl acetoacetal resin 4.0 parts (ESREC KS -5 Sekisui Chemical Co., Ltd.)
・ Polyolefin wax 0.2 parts ・ Neoethanol 4.2 parts ・ Toluene 42.1 parts ・ Methyl ethyl ketone 42.1 parts

(Comparative Example 1)
In place of the black dye layer coating solution 1 used in Example 1, the same conditions as in Example 1 were used except that a black dye layer coating solution 13 having the following composition was used. A thermal transfer sheet was obtained.

<Black Dye Layer Coating Solution 13 (D / B Ratio = 1.8)>
• 2.0 parts of the compound represented by the above general formula (8) as a yellow sublimation dye • 1.4 parts of the compound represented by the above general formula (15) as a magenta sublimation dye • 5-1) Compound 3.8 parts, polyvinyl acetoacetal resin 4.0 parts (S-REC KS-5, manufactured by Sekisui Chemical Co., Ltd.)
・ Polyolefin wax 0.2 parts ・ Neoethanol 4.2 parts ・ Toluene 42.1 parts ・ Methyl ethyl ketone 42.1 parts

(Comparative Example 2)
In place of the black dye layer coating solution 1 used in Example 1 above, the black dye layer coating solution 14 having the following composition was used, except that the same conditions as in Example 1 were used. A thermal transfer sheet was obtained.

<Black Dye Layer Coating Liquid (D / B Ratio = 1.8)>
・ 1.2 parts of a compound represented by the above general formula (1-1) as a yellow sublimable dye 1.4 parts of a compound represented by the above general formula (7-1) as a magenta sublimable dye ・ as a cyan sublimable dye Compound represented by the above general formula (20) 4.6 parts, polyvinyl acetoacetal resin 4.0 parts (ESREC KS-5 manufactured by Sekisui Chemical Co., Ltd.)
・ Polyolefin wax 0.2 parts ・ Neoethanol 4.2 parts ・ Toluene 42.1 parts ・ Methyl ethyl ketone 42.1 parts

(Comparative Example 3)
Instead of the black dye layer coating liquid 1 used in Example 1, the yellow dye layer coating liquid, the magenta dye layer coating liquid, and the cyan dye layer coating liquid having the following compositions were used, respectively. A thermal transfer sheet of Comparative Example 3 was obtained under the same conditions as in Example 1 except that a yellow dye layer, a magenta dye layer, and a cyan dye layer were formed in the surface order instead of the black dye layer.

<Coating liquid for yellow dye layer (D / B ratio = 0.9)>
・ 2.6 parts of a compound represented by the above general formula (1-1) as a yellow sublimable dye 3.0 parts of polyvinyl acetoacetal resin (manufactured by SREC KS-5 by Sekisui Chemical Co., Ltd.)
・ Polyolefin wax 0.1 part ・ Toluene 47.2 parts ・ Methyl ethyl ketone 47.2 parts

<Coating liquid for magenta dye layer (D / B ratio = 1.9)>
・ 3.0 parts of a compound represented by the above general formula (4-1) as a magenta sublimable dye 3.0 parts of a polyvinyl acetoacetal resin (manufactured by ESREC KS-5 Sekisui Chemical Co., Ltd.)
・ Polyolefin wax 0.1 part ・ Toluene 47.0 parts ・ Methyl ethyl ketone 47.0 parts

<Cyan dye layer coating solution (D / B ratio = 1.3)>
-3.8 parts of the compound represented by the above general formula (5-1) as a cyan sublimable dye-3.0 parts of polyvinyl acetoacetal resin (S-REC KS-5, manufactured by Sekisui Chemical Co., Ltd.)
・ Polyolefin wax 0.1 part ・ Toluene 46.6 parts ・ Methyl ethyl ketone 46.6 parts

(Evaluation)
Using each of the thermal transfer sheets of Examples 1 to 12 and Comparative Examples 1 to 3, a black print portion having a gradation of 16 steps was printed on the thermal transfer sheet prepared by the following method under the following printing conditions. For all 16 gradations, a spectrophotometer (GretagMacbeth Spectrolino: Gretag) is used, the white reference is the absolute value, D50, D65, C, F6 light sources (fluorescent lamp white), and the observation visual field of 2 ° is the standard of concentration. The chromaticity values (a * and b *) were measured and evaluated according to the following criteria. In the thermal transfer sheet of Comparative Example 3, yellow, magenta, and cyan were overprinted.

<Creation of thermal transfer image receiving sheet>
On a porous film layer made of a porous polyethylene film (Toyopearl-SS P4255, Toyobo Co., Ltd., thickness 35 μm), an intermediate layer coating solution and a receiving layer coating solution having the following composition are obtained by a gravure reverse coating method. By applying and drying sequentially, an intermediate layer and a receiving layer were formed. The adhesive layer is formed by applying and drying to the porous polyethylene film on the opposite side of the surface on which the intermediate layer and the receiving layer are provided, using a gravure reverse roll coat method using an adhesive layer coating solution having the following composition: Then, an RC base paper (155 g / m ² , thickness 151 μm) (Mitsubishi Paper Co., Ltd.) and a thermal transfer image receiving sheet were prepared. Each of the above coating amounts was a solid content, the intermediate layer was 1.5 g / m ² , the receiving layer was 5.0 g / m ² , and the adhesive layer was 5 g / m ² .

<Intermediate layer coating solution>
・ Polyester resin 50 parts (Polyester WR-905 Nippon Synthetic Chemical Industry Co., Ltd.)
・ Titanium oxide 20 parts (TCA888 Tochem Products)
・ Fluorescent brightener 1.2 parts (Ubitex BAC Ciba Specialty Chemicals Co., Ltd.)
Water / isopropyl alcohol = 1/1 28.8 parts

<Coating solution composition for receiving layer>
・ 60 parts of vinyl chloride-vinyl acetate copolymer (Solvine C, Nissin Chemical Industry Co., Ltd.)
・ Epoxy-modified silicone 1.2 parts (X-22-3000T, Shin-Etsu Chemical Co., Ltd.)
・ Methylstil modified silicone 0.6 parts (X-24-510, Shin-Etsu Chemical Co., Ltd.)
・ Methyl ethyl ketone / toluene (mass ratio 1/1) 5 parts

<Coating liquid for adhesive layer>
・ Urethane resin 30 parts (Takelac A-969V Mitsui Takeda Chemical Co., Ltd.)
・ Isocyanate 10 parts (Takenate A-5 Mitsui Takeda Chemical Co., Ltd.)
・ 100 parts of ethyl acetate

<Printing conditions>
-Heating element average resistance: 5545Ω
Print density in the main scanning direction: 300 dpi, printing density in the sub-scanning direction: 300 dpi
・ Printing voltage: 29V
・ One line cycle; 2msec / line
・ Printing start temperature: 25 ℃

(Evaluation criteria)
A: All a * and b * values of 16 gradations with all light sources are in the range of -5 to 5.
A: All a * and b * values of 16 gradations with the F6 light source are in the range of −5 to 5.
Δ: a * and b * values less than −5 or greater than 5 except for F6 light source.
X: a * and b * values less than −5 including F6 light source or greater than 5.

  Table 1 below summarizes the characteristics and evaluation results of the thermal transfer sheets of Examples 1 to 12 and Comparative Examples 1 to 3.

  From the evaluation results, it can be seen that the thermal transfer sheet according to the example of the present invention can reproduce a desired “black” even when exposed to a light source other than a fluorescent lamp.

DESCRIPTION OF SYMBOLS 10 ... Thermal transfer sheet 1 ... Base material 2Bk ... Black dye layer 3 ... Primer layer 5 ... Back layer

Claims (2)

A thermal transfer sheet provided with a black dye layer on a substrate,
The black dye layer contains at least a sublimable dye represented by the following general formula (1),
A thermal transfer sheet comprising one or more sublimable dyes selected from the group consisting of sublimable dyes represented by the following general formulas (2) to (5).

(Ring A in General Formula (1) represents a substituted or unsubstituted aryl group, and R ¹ and R ² are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted allyl group. Represents a substituted or unsubstituted aryl group or a substituted or unsubstituted cycloalkyl group, and R ³ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, Or represents a hydrogen atom, and R ⁴ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.

(In the general formula (2), R ¹ and R ² are a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group or a substituted or unsubstituted aralkyl group, and R ³ is a substituted or unsubstituted alkyl group. Substituted or unsubstituted alkoxy group, substituted or unsubstituted alkylcarbonylamino group, substituted or unsubstituted alkylsulfonylamino group, substituted or unsubstituted alkylaminocarbonyl group, substituted or unsubstituted alkylaminosulfonyl group, hydrogen An atom or a halogen atom, R ⁴ is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted cycloalkyl group, a cyano group, a nitro group or a halogen atom; N represents an integer of 1 to 4.)

(R ^{1 to} R ⁴ in the general formula (3) each independently represents a substituted or unsubstituted alkyl group.)

(R ¹ and R ² in the general formula (4) are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, an allyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted cycloalkyl group. R ³ represents a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, a methyl group, or a halogen atom, and R ⁴ represents a methyl group, a methoxy group, a formylamino group, or an alkyl having 1 to 4 carbon atoms. Represents a carbonylamino group, an alkylsulfonylamino group having 1 to 8 carbon atoms, or an alkoxycarbonylamino group having 1 to 8 carbon atoms, and R ⁵ represents a hydrogen atom, a nitro group, or a substituted or unsubstituted alkyl group. Represents.)

(Ring A in the general formula (5) represents a substituted or unsubstituted aryl group, and R ¹ and R ² are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, an allyl group, a substituted or unsubstituted group. Of the aryl group, or a substituted or unsubstituted cycloalkyl group.) The thermal transfer according to claim 1, wherein the black dye layer further contains one or both of sublimable dyes represented by the following general formula (6) and general formula (7). Sheet.

(In formula (6) X and Y are each independently in, -S -, - O-, or -SO ₂ - represent, respectively R ¹ and R ² are independently a substituted or unsubstituted alkyl group, Represents a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted allyl group.)

(X in the general formula (7) represents —S—, —O—, or —SO ₂ —, and R ¹ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or Represents an unsubstituted aryl group or a substituted or unsubstituted allyl group.)

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