JP2004230878A - Thermal transfer ink, thermal transfer sheet, and thermal transfer recording method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermal transfer recording material which exhibits a clear yellow with high energy and low energy, and is excellent in color tone and light fastness, and has a high density and a favorable green color tone even when mixed with cyan. Provided are a yellow ink for thermal transfer and a sheet for thermal transfer.
SOLUTION: A thermal transfer ink containing a dye having an arylidenepyrazolone skeleton, a dye having a bispyrazolonemethine skeleton, and a medium, a dye having an arylidenepyrazolone skeleton on a substrate, and bispyrazolone methine Thermal transfer sheet with coloring material layer containing skeleton dye [selection figure] None

Description

  The present invention relates to a thermal transfer ink, a thermal transfer recording sheet used for thermal transfer recording, particularly a dye transfer type thermal transfer recording, and a thermal transfer recording method using the same.

  Dye transfer type thermal transfer recording is performed by superposing a thermal transfer sheet having a color material layer containing a heat transferable dye on a base film and an image receiving sheet having a dye receiving layer on the surface, and heating the thermal transfer sheet. Is a recording method for performing recording by transferring a dye in a heat-sensitive transfer sheet to an image receiving sheet. This recording method is applied to full-color image recording such as a video printer, because gradation transfer can be performed by controlling the amount of dye transferred by the amount of heating energy.

In such dye transfer type thermal transfer recording, the dye used in the transfer sheet and the ink composition for the transfer sheet greatly affects the speed of transfer recording, the image quality of the recorded matter, storage stability, and the like. The properties of this dye are very important, and such a dye must satisfy the following conditions.
1) Easily sublimate and / or thermally diffuse under the operating conditions of the thermal recording head.

2) Do not thermally decompose under the operating conditions of the thermal recording head.
3) To have favorable hue in color reproduction.
4) The molecular extinction coefficient must be large.
5) Stable against heat, light, moisture, chemicals, etc.
6) Easy synthesis.

7) Excellent ink suitability.
8) There should be no safety issues.
Conventionally, among dyes used for such thermal transfer recording, it is known that an arylidene pyrazolone dye represented by the general formula (I) is used as a dye for sublimation type thermal transfer recording ( For example, see Patent Documents 1 to 3. Also, a combination system of an arylidenepyrazolone dye and a specific dicyanomethine yellow dye and a combination system of an arylidenepyrazolone dye and a specific pyridoneazo yellow dye are known (see Patent Documents 2 and 3).

It is also known to use a bispyrazolone methine dye represented by the general formula (II) as a dye for thermal transfer recording of a sublimation method, and a bispyrazolone methine dye and a specific pyrazolone azo yellow dye are used. A combination of a bispyrazolone methine dye and a specific pyridone azo yellow dye, a combination of a bispyrazolone methine dye and a specific quinophthalone yellow dye, and a specific dye containing a bispyrazolone methine dye Three types of combined systems are described (for example, see Patent Documents 4 to 7).
JP-A-2-3450 JP-A-4-265792 JP-A-4-275184 JP-A-10-864 JP-A-10-181224 JP-A-10-203029 JP 2000-103174 A

  However, with any of the above-mentioned prior arts, the dyes or dye mixtures specifically disclosed could not yet provide sufficient performance as shown in Comparative Examples described later. Therefore, development of thermal transfer recording inks and sheets having high recording density, vivid color tone of the recorded matter, high stability of the recorded matter, and excellent overall properties as a yellow dye for thermal transfer recording is desired. Had been rare.

  The present invention has excellent overall performance in all of the properties 1) to 8) required for the dye for thermal transfer recording, especially high recording density, clear color tone of the recorded matter, An object of the present invention is to provide a thermal transfer ink, a thermal transfer sheet, and a thermal transfer recording method, which have high stability of recorded matter.

The thermal transfer ink of the present invention is characterized by containing a dye having an arylidenepyrazolone skeleton, a dye having a bispyrazolonemethine skeleton, and a medium.
The thermal transfer recording sheet of the present invention is characterized in that it has a colorant layer containing a dye having an arylidenepyrazolone skeleton, a dye having a bispyrazolonemethine skeleton, and a binder on a substrate.

The thermal transfer recording method of the present invention is a method of performing thermal transfer recording using such a thermal transfer sheet of the present invention, and the recorded image is set to a 2 degree viewing angle using a D50 light source. In this case, the a * value in the CIELAB space at a color density of 1.0 is -13 or more and 10 or less, and the b * value is 60 or more.
That is, the present inventors have conducted a detailed study on a yellow dye mixture for thermal transfer recording in order to achieve the above object. As a result, the following dye (A) having an arylidenepyrazolone methine skeleton and the following (B) bis By using a dye having a pyrazolone methine skeleton in combination, it is possible to obtain a recorded matter having a high recording density, a clear color tone of the recorded matter, a high stability of the recorded matter, and an overall superior to the conventional product. They have found that they can do this and have reached the present invention.

Note that, in the above formula, a dotted line indicates that the compound is unsubstituted or has an optional substituent.
That is, the above dye having an arylidenepyrazolone skeleton has high sensitivity in thermal transfer recording, but has a reddish tint as a yellow dye and is insufficient in color tone. By combining a dye having a bispyrazolone methine skeleton with such a dye having an arylidenepyrazolone skeleton, a dye having excellent overall color tone, sensitivity, light resistance, and the like can be obtained. This is because the dye having a bispyrazolone methine skeleton exhibits a greenish yellow color tone, so that the redness of the dye having the arylidene pyrazolone skeleton can be suppressed, and sensitivity and light resistance can be maintained. Things.

INDUSTRIAL APPLICABILITY The thermal transfer ink and sheet of the present invention are suitable as a thermal transfer yellow ink and a thermal transfer yellow sheet, and can suitably obtain a dye having a maximum absorption wavelength (λmax) of a dye of 350 to 480 nm. .

According to the present invention, the dye for thermal transfer recording has excellent overall performance in all properties required, high sensitivity, high recording density, clear color tone of recorded matter, and stable recorded matter. The present invention provides a thermal transfer recording dye, a thermal transfer recording ink, a thermal transfer recording sheet, and a thermal transfer recording method using the same.
In particular, according to the present invention, it is possible to obtain a heat-sensitive transfer recording material which exhibits a clear yellow having a low energy and a high density, has a favorable color tone as a yellow color, and has a remarkably good light fastness, and a color mixture with cyan. A green tone having a preferable tone can be obtained at a high density, and the obtained recorded matter has very good light fastness.

Hereinafter, embodiments of the present invention will be described in detail.
First, a dye having an arylidenepyrazolone skeleton and a dye having a bispyrazolone methine skeleton used in the present invention will be described.
In the following, the preferred carbon number of the exemplified group indicates the total carbon number including the carbon number of the substituent when the group has a substituent.

  The dye having an arylidenepyrazolone skeleton used in the present invention is preferably an arylidenepyrazolone dye represented by the following general formula (I). In the following general formula (I), 1 to 4 indicate the positions of the substituents on ring A.

  In the general formula (I), the ring A is a benzene ring optionally having a substituent, preferably an alkyl group having 1 to 10 carbon atoms which may be substituted, and a substituted benzene ring having 1 to 10 carbon atoms. A benzene ring which may be substituted with a substituent selected from the group consisting of an alkoxy group and a halogen atom which may be substituted, and when the benzene ring has a substituent, the substitution position thereof is 1 to 4 (1 to 4 (Position 3), but is preferably the third position (position 3).

R ¹ and R ² 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; Preferably, an optionally substituted alkyl group having 1 to 12 carbon atoms, an allyl group, an optionally substituted aryl group having 6 to 10 carbon atoms, or an optionally substituted 5 to 7 carbon atoms A good cycloalkyl group.

R ³ is a hydrogen atom, an optionally substituted alkyl group, an NR ⁹ R ¹⁰ group, an optionally substituted alkoxy group, an optionally substituted alkoxycarbonyl group, an optionally substituted aryl group, Or a C (O) NR ^9A R ^10A group, preferably a hydrogen atom, an alkyl group having 1 to ¹⁰ carbon atoms which may be substituted, an NR ⁹ R ¹⁰ group having 1 to 8 carbon atoms, An optionally substituted alkoxy group having 1 to 8 carbon atoms, an optionally substituted alkoxycarbonyl group having 2 to 9 carbon atoms, an optionally substituted aryl group having 6 to 10 carbon atoms, or 3 to 9 carbon atoms C (O) NR ^9A R ^10A group.

R ⁴ represents an alkyl group which may be substituted or an aryl group which may be substituted, and among these, preferably, an alkyl group which may have 1 to 12 carbon atoms and may be substituted, or 6 to 6 carbon atoms. It is an aryl group which may have 10 substituents.
Here, R ⁹ , R ¹⁰ , R ^9A and R ^10A each independently represent a hydrogen atom, an optionally substituted alkyl group, or an optionally substituted aryl group. An atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, or an optionally substituted aryl group having 6 to 10 carbon atoms.

In particular, R ¹ and R ² are each independently preferably a linear or branched alkyl group having 1 to 8 carbon atoms, and R ³ is a linear or branched alkyl group having 1 to 4 carbon atoms. Alkoxy group,
A linear or branched dialkylamino group having 1 to 8 carbon atoms, or a linear or branched alkoxycarbonyl group having 2 to 9 carbon atoms is preferable, and R ⁴ is a phenonyl group or a substituent. A phenyl group having a halogen atom is preferred.

  The dye having a bispyrazolone methine skeleton used in the present invention is preferably a bispyrazolone methine dye represented by the following general formula (II).

In the general formula (II), R ⁵ and R ⁶ each independently represent an alkyl group which may be substituted, an alkenyl group which may be substituted, or an aryl group which may be substituted. Preferably, it is a C1-C10 optionally substituted alkyl group, a C1-C10 optionally substituted alkenyl group, or a C6-C10 optionally substituted aryl group. .

R ⁷ and R ⁸ each independently represent an optionally substituted alkyl group, an NR ^9B R ^10B group,
Represents an alkoxy group which may be substituted, an alkoxycarbonyl group which may be substituted, an aryl group which may be substituted, or a C (O) NR ^{9 C} R ^{10 C} group; 10 optionally substituted alkyl group, NR ^9B R ^10B group having 1 to 8 carbon atoms, an optionally substituted alkoxy group having 1 to 8 carbon atoms, may be substituted for 2 to 9 carbon atoms It is an alkoxycarbonyl group, an optionally substituted aryl group having 6 to 10 carbon atoms, or a C (O) NR ^{9 C} R ^{10 C} group having 3 to 9 carbon atoms.

Here, R ^9B , R ^10B , R ^9C and R ^10C each independently represent a hydrogen atom, an optionally substituted alkyl group, or an optionally substituted aryl group. An atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, or an optionally substituted aryl group having 6 to 10 carbon atoms.
In particular, R ⁵ and R ⁶ each independently represent a linear or branched alkyl group having 1 to 8 carbon atoms, a phenyl group having 6 to 10 carbon atoms, or a phenyl group having a halogen atom as a substituent. Is preferred,
R ⁷ and R ⁸ are each independently preferably a linear or branched alkyl group having 1 to 8 carbon atoms.

Among them, as the bispyrazolone methine dye represented by the general formula (II), those in which R ⁵ and R ⁶ are phenyl groups and R ⁷ and R ⁸ are methyl groups are most preferable. C. I. A compound known as Solvent Yellow 93.
In the above general formulas (I) and (II), R ^{1 to} R ¹⁰ , R ^9A , R ^10A , R ^9B , R ^10B , R ^9C , R ^10C and the alkyl group of the substituent of the ring A have 1 carbon atoms. To 12, preferably a linear or branched alkyl group having 1 to 10 carbon atoms, specifically, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and an n-butyl group. , I-butyl group, t-butyl group, n-hexyl group, n-octyl group, 2-ethylhexyl group and the like.

When the alkyl group is substituted, examples of the substituent include a halogen atom, an alkoxy group, an aryl group, a cyano group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, and an acyloxy group. Preferred specific examples include the following.
An alkoxy-substituted alkyl group such as a 2-ethoxyethyl group, a 2-n-propoxyethyl group, a 2-n-butoxyethyl group, a 4-i-propoxybutyl group, a 3-i-butoxypropyl group; a 2-chloroethyl group; Halogen-substituted alkyl groups such as 4-chlorobutyl group and trifluoromethyl group; cyano-substituted alkyl groups such as cyanoethyl group; aryl-substituted alkyl groups such as benzyl group, 2-phenylethyl group and p-chlorobenzyl group; phenoxy Aryloxy-substituted alkyl groups such as methyl group, 2-phenoxyethyl group and 4-phenoxybutyl group; alkoxycarbonyl groups such as 2-methoxycarbonylethyl group, 3-n-butoxycarbonylpropyl group and 2-allyloxycarbonylethyl group A group-substituted or allyloxycarbonyl-substituted alkyl group; 2 Aryloxycarbonyl-substituted alkyl groups such as phenoxycarbonylethyl group and 4-p-chlorophenoxycarbonylbutyl group; aralkyloxy-substituted alkyl groups such as 2-benzyloxyethyl group and 4-benzyloxybutyl group; 2-acetoxyethyl An acyloxy-substituted alkyl group such as a group, 2-benzoyloxyethyl group or 4-acetoxybutyl group.

Among them, the alkyl group having a substituent preferably has 1 to 8 carbon atoms.
As the aryl group of R ^{1 to} R ¹⁰ , R ^9A , R ^10A , R ^9B , R ^10B , R ^9C and R ^10C, a linear or branched alkyl group having 1 to 8 carbon atoms; fluorine atom, chlorine A halogen atom such as an atom or a bromine atom; a fluoroalkyl group having 1 to 4 carbon atoms; and a substituent selected from the group consisting of a linear or branched alkoxy group having 1 to 8 carbon atoms and the like. And a good phenyl group.

Examples of the cycloalkyl group as R ¹ and R ² include a cycloalkyl group having 5 to 7 carbon atoms such as a cyclopentyl group and a cyclohexyl group.
Examples of the alkoxy group for R ³ , R ⁷ , R ⁸ and the substituent of ring A include a methoxy group, an ethoxy group,
1 to 12 carbon atoms such as n-propoxy group, i-propyloxy group, n-butyloxy group, i-butyloxy group, t-butyloxy group, n-hexyloxy group, n-octyloxy group and 2-ethylhexyloxy group. And preferably an alkoxy group having 1 to 8 carbon atoms.

When the alkoxy group is substituted, the substituent includes a halogen atom, an alkoxy group,
Examples include an aryl group, a cyano group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, and an acyloxy group.
Examples of the alkoxycarbonyl group for R ³ , R ⁷ and R ⁸ include a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an i-propyloxycarbonyl group, an n-butyloxycarbonyl group, an i-butyloxycarbonyl group, Examples thereof include alkoxycarbonyl groups having 2 to 12 carbon atoms, preferably 2 to 8 carbon atoms, such as a t-butyloxycarbonyl group, an n-hexyloxycarbonyl group, an n-octyloxycarbonyl group, and a 2-ethylhexyloxycarbonyl group.

When the alkoxycarbonyl group is substituted, examples of the substituent include a halogen atom, an alkoxy group, an aryl group, a cyano group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, and an acyloxy group.
Examples of the halogen atom for the substituent of ring A include a fluorine atom, a chlorine atom, and a bromine atom.

  In the present invention, as long as the dye having the skeletal structure is used in combination, the effects of the present invention can be obtained.However, in order to sufficiently exert the effects of the present invention by these combinations, the skeleton portion and other The dye having the arylidenepyrazolone skeleton, including the partial structure, has a molecular weight of usually 600 or less, particularly 500 or less, particularly in the range of 240 to 500, and the dye having a bispyrazolonemethine skeleton has a molecular weight of usually 600 or less. , Particularly preferably 500 or less, particularly preferably in the range of 200 to 500.

  Specific examples of the dyes represented by the general formulas (I) and (II) are shown in the following Tables 1 and 2, respectively, but are not limited thereto. These dyes can be produced according to the methods described in, for example, JP-A-2-3450 and JP-A-49-114420.

  In the thermal transfer recording ink and the thermal transfer recording sheet of the present invention, the ratio of the dye having an arylidenepyrazolone skeleton to the dye having a bispyrazolonemethine skeleton is such that the dye having an arylidenepyrazolone skeleton: a dye having a bispyrazolone methine skeleton. Dye = 1: 9 to 9: 1 (weight ratio), preferably 2: 8 to 8: 2, particularly preferably 3: 7 to 7: 3. Even if the amount of the dye having the arylidenepyrazolone skeleton is larger or smaller than the above range, the effect of the present invention by using the dye having the bispyrazolonemethine skeleton in combination cannot be sufficiently obtained.

  As long as the effect of the present invention is not impaired, it can be used in combination with other yellow dyes.However, the content of the other yellow dyes is usually the dye having an arylidenepyrazolone skeleton of the present invention and bispyrazolone methine. 40 parts by weight or less, preferably 30 parts by weight or less, more preferably 20 parts by weight or less, still more preferably 10 parts by weight or less, particularly preferably 5 parts by weight or less with respect to the case where the total amount of the skeleton-containing dye is 100 parts by weight. Not more than parts by weight.

In order to satisfy the requirement standard of SWOP (Specifications Web Offset publications) color, the ratio may be appropriately selected within the above range. For example, a dye having an arylidenepyrazolone skeleton: a dye having a bispyrazolone methine skeleton = 3: 7 ~ 5: 5 (weight ratio).
The thermal transfer ink of the present invention is obtained by dissolving or dispersing a dye having an arylidenepyrazolone skeleton and a dye having a bispyrazolone methine skeleton in a medium.

  Examples of the medium include water, alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and isobutyl alcohol, cellosolves such as methyl cellosolve and ethyl cellosolve, aromatics such as toluene, xylene, and chlorobenzene, ethyl acetate, and butyl acetate. Esters, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; chlorine solvents such as methylene chloride, chloroform and trichloroethylene; ethers such as tetrahydrofuran and dioxane; N, N-dimethylformamide, N-methylpyrrolidone And these may be used alone or as a mixture of two or more.

In the ink of the present invention, in addition to the dye and the medium, if necessary, organic and inorganic non-sublimable fine particles, a dispersant, an antistatic agent, an antifoaming agent, an antioxidant, a viscosity modifier and the like are added. Agents can be added.
In the thermal transfer ink of the present invention, the total concentration of the dye is preferably 0.5 to 20 parts by weight, particularly 1 to 15 parts by weight, particularly preferably 2 to 15 parts by weight, per 100 parts by weight of the ink. The proportion of the above-mentioned additives other than the pigment is 5 parts by weight or less, especially 3 parts by weight or less in 100 parts by weight of the ink, and the lower limit of adding these additives is 0.01%. It is preferably at least 0.5 part by weight, especially at least 0.5 part by weight.

  The thermal transfer sheet of the present invention has a coloring material layer containing a dye having an arylidenepyrazolone skeleton and a dye having a bispyrazolonemethine skeleton on a substrate. The coloring material layer may contain a yellow dye having a different structure other than a dye having an arylidenepyrazolone skeleton and a dye having a bispyrazolonemethine skeleton, as long as the effects of the present invention are not impaired.

The method of forming the colorant layer on the substrate is not particularly limited, but usually, an ink is prepared by dissolving or dispersing the dye together with the binder in the above-described medium, and forming the ink on the substrate. A method of applying and drying on the top is adopted.
Examples of the binder used herein include cellulose-based, acrylic acid-based, starch-based, and epoxy-based water-soluble resins, acrylic resin, methacrylic resin, polystyrene, polycarbonate, polyether sulfone, polyvinyl butyral, and ethyl cellulose. Resins soluble in organic solvents such as acetyl cellulose, polyester, AS resin, and phenoxy resin can be used. The ratio between the binder and the dye in the thermal transfer ink for forming the color material layer is usually The ratio of agent: dye = 1: 2 to 2: 1 (weight ratio) is appropriate. As the binder, one kind may be used alone, or two or more kinds may be used in combination.

As a base film as a base material on which ink for forming a transfer sheet is applied, thin paper such as condenser paper and glassine paper, and a heat-resistant plastic film such as polyester, polycarbonate, polyamide, polyimide, and polyaramid are used. The thickness is preferably in the range of usually 3 to 50 μm.
Among the above base films, a polyethylene terephthalate film is particularly advantageous in consideration of mechanical strength, solvent resistance, economy, and the like. However, in some cases, the polyethylene terephthalate film does not always have sufficient heat resistance and the runnability of the thermal head is insufficient, so that the lubricant on the surface opposite to the surface on which the color material layer is formed has high lubricity. By providing a heat-resistant resin layer containing heat-resistant fine particles, a surfactant, a binder and the like, a thermal head having improved running properties can be used. In this case, examples of the lubricant include modified silicone compounds such as an amino-modified silicone compound and a carboxy-modified silicone compound, examples of the heat-resistant fine particles include fine particles such as silica, and examples of the binder include an acrylic resin. . The thickness of the heat-resistant resin layer is usually preferably in the range of 0.1 to 50 μm.

The application of the ink to the base film can be carried out using a gravure coater, a reverse roll coater, a rod coater, an air doctor coater, or the like. It is preferable to apply the coating so as to have a range of 5 μm.
The heat-sensitive transfer sheet of the present invention can use not only a thermal head but also an infrared ray or a laser beam as a heating means. In addition, a current-carrying film that generates heat by passing electricity through the base film itself can be used as a current-carrying dye transfer sheet.

In thermal transfer recording, usually, color printing is performed by repeating a thermal recording operation on a transfer sheet of three colors of yellow, magenta, and cyan, or four colors including black. The hue of the obtained image is represented by L ^* value, a ^* value, b ^* value in CIELAB space, and the hue is compared from the a ^* value and b ^* value in images having similar color density and L ^* value. be able to.
According to the present invention, in terms of color reproduction of a color image, a hue preferable as a hue of yellow, that is, a ^* value at a color density of 1.0 when a 2 degree viewing angle is set using a D50 light source,
-13 or more and 10 or less, particularly -13 or more and 5 or less, b ^* value is 60 or more, preferably 65 or more,
In particular, those of 70 or more can be achieved. This range includes the color standard SWOP (Specifications Web Offset Publications) of the color proof ink used in the printing industry.

Also, the transfer density is excellent. For example, the color density when recorded by the method of the embodiment of the present invention is usually 1.8 or more, preferably 2.0 or more.
Further, the yellow recording image (color density about 1.0) using the ink of the present invention was obtained by using a xenon weatherometer Ci4000 (manufactured by Atlas) with a black panel temperature of 58 ± 3 ° C. and light fastness after irradiation for 40 hours. The degree of discoloration {ΔE (L *, a *, b *)} of the recorded matter after the resistance test is 10
And preferably 5 or less, and an indoaniline-based cyan dye, specifically, an indoaniline-based dye represented by the structural formula (III) used in the following examples. Light fastness test result of green color recorded image (color density about 1.0) used ｛ΔE (L *,
a *, b *)} are also 20 or less, preferably 15 or less, and have excellent light resistance even when mixed with a cyan dye.

  The ink for thermal transfer and the thermal transfer sheet of the present invention have a high recording density of thermal transfer recording, a clear color tone of the recorded matter, a high stability of the recorded matter, and are generally excellent in light resistance of the recorded matter. Is excellent, and the production of the dye is easy, so that it can be industrially advantageously produced.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded.
Example 1
The mixture having the following composition was treated with an ultrasonic cleaner for 30 minutes to prepare ink (Y) and ink (C).

[Formulation of ink (Y) (parts by weight)]
No. Dye 1-1: 3.0
No. Dye 2-1: 3.0
Phenoxy resin (“PKHJ” manufactured by Union Carbide): 10
Tetrahydrofuran: 90
[Formulation of ink (C) (parts by weight)]
Cyan dye (Structural formula (III)): 8.0
Phenoxy resin (“PKHJ” manufactured by Union Carbide): 10
Tetrahydrofuran: 90

  The resulting inks (Y) and (C) are each coated on a polyethylene terephthalate film (6 μm thick) using a wire bar and dried (dry film thickness: about 1 μm) to form a color material layer. 10 parts by weight of an acrylic resin (trade name: BR-80; manufactured by Mitsubishi Rayon Co., Ltd.), 1 part by weight of amino-modified silicone oil (trade name: KF393; manufactured by Shin-Etsu Chemical Co., Ltd.), and 89 parts by weight of toluene The heat-sensitive transfer sheet (Y) and the heat-sensitive transfer sheet (C) were obtained by coating and drying (dry film thickness: about 1 μm) the liquid composed of the above-mentioned parts.

The obtained thermal transfer sheet (Y) is connected to an ink ribbon of VM-MPA50 of a printer "NV-MPX5" manufactured by Matsushita Electric Industrial Co., Ltd., and "NV" manufactured by Matsushita Electric Industrial Co., Ltd. is attached to a recording paper of VM-MPA50. When a gradation image was recorded by using "-MPX5", a recorded matter having a yellow color tone having the maximum print density shown in Table 3 was obtained.
The a ^* value and b ^* value in CIELAB space were measured when the viewing angle was set to 2 degrees using a D50 light source at a color density of 1.0. The results are shown in Table 3.

The color density, CIELAB a ^* value, and b ^* value were measured using a spectrophotometer (trade name: SPM-50, manufactured by Gretag).
The transfer sheets (Y) and (C) were superposed in this order on the same image receiving body under the same recording conditions as described above, and transfer recording was performed to obtain a recorded material having a green color tone.
Further, a light fastness test of the obtained yellow tone recorded matter and green tone recorded matter (having a color density of about 1.0) was carried out using a Xenon weatherometer Ci4000 (manufactured by Atlas) (black panel temperature: Table 3 shows the degree of discoloration {ΔE (L *, a *, b *)} of the recorded matter after irradiation for 40 hours at 58 ± 3 ° C.).

Examples 2-3
In Example 1, the preparation of the ink, the preparation of the heat-sensitive transfer sheet, the transfer recording, and the light resistance test were performed in the same manner except that the yellow dye shown in Table 3 was used, and the results are shown in Table 4. .
Comparative Examples 1 to 9
In Example 1, the preparation of the ink, the preparation of the heat-sensitive transfer sheet, the transfer recording, and the light resistance test were performed in the same manner except that the yellow dye shown in Table 3 was used, and the results are shown in Table 4. . Here, the structures of the dyes A to G are as shown below.

  Dye A (Dye W described in JP-A-4-265792)

  Dye B (Dye A described in JP-A-4-275184)

  Dye C (CI Solvent Yellow 16 described in JP-A-10-864)

  Dye D (Dye 1-1 described in JP-A-10-181224)

  Dye E (dye represented by structural formula (II) described in JP-A-10-203029)

  Dye F (Dye 2-1 described in JP-A-2000-103174)

  Dye G (Dye 3-1 described in JP-A-2000-103174)

In addition, in Comparative Example 2, The dye No. 1-2 is No. 1 described in JP-A-2-3450. No. 1 of Comparative Example 3, The dye 2-1 is a dye (CI Solvent Yellow) used in Example 1 described in JP-A-10-864.
93).
Comparative Example 4 corresponds to the combination of dyes used in Examples described in JP-A-4-265792, and Comparative Example 5 corresponds to the combination of dyes used in Examples described in JP-A-4-275184. Comparative Example 6 corresponds to the combination of dyes used in Example 3 described in JP-A-10-864, and Comparative Example 7 corresponds to Example 1 described in JP-A-10-181224. Comparative Example 8 corresponds to the combination of dyes used in Example 1 of JP-A-10-203029, and Comparative Example 9 corresponds to the implementation of JP-A-2000-103174. This corresponds to the combination of dyes used in Example 1.

As is clear from the comparison between the above Examples and Comparative Examples, according to the present invention, it is clear that a printed matter having an excellent transfer density can be obtained by balancing the a ^* value and the b ^* value.
Example 4
Using an ink prepared by the following method in place of the ink used in Example 1, a transfer sheet was prepared in the same manner as in Example 1, and transfer recording and evaluation were performed. As a result, recording with uniform color density was obtained. It was confirmed that the obtained recorded matter had good light fastness.

[Ink formulation (parts by weight)]
No. Dye 1-1: 3.0
No. Dye 2-1: 3.0
AS resin (product name: Denka AS-S; product of Denki Kagaku Kogyo Co., Ltd.): 10
Toluene: 70
Cyclohexanone: 10

Claims (11)

A thermal transfer ink comprising a dye having an arylidenepyrazolone skeleton, a dye having a bispyrazolonemethine skeleton, and a medium. The thermal transfer ink according to claim 1, wherein the dye having an arylidenepyrazolone skeleton is an arylidenepyrazolone-based dye represented by the following general formula (I).

(Wherein, ring A represents a benzene ring which may have an optional substituent,
R ¹ and R ² 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 ³ is a hydrogen atom, an optionally substituted alkyl group, an NR ⁹ R ¹⁰ group, an optionally substituted alkoxy group, an optionally substituted alkoxycarbonyl group, an optionally substituted aryl group, Or a C (O) NR ^9A R ^10A group,
R ⁴ represents an optionally substituted alkyl group or an optionally substituted aryl group.
R ⁹ , R ¹⁰ , R ^9A , and R ^10A each independently represent a hydrogen atom, an optionally substituted alkyl group, or an optionally substituted aryl group. ) 3. The thermal transfer ink according to claim 1, wherein the dye having a bispyrazolone methine skeleton is a bispyrazolone methine dye represented by the following general formula (II).

(Wherein, R ⁵ and R ⁶ each independently represent an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group;
R ⁷ and R ⁸ each independently represent an optionally substituted alkyl group, an NR ^9B R ^10B group,
Represents an optionally substituted alkoxy group, an optionally substituted alkoxycarbonyl group, an optionally substituted aryl group, or a C (O) NR ^{9 C} R ^{10 C} group.
R ^9B , R ^10B , R ^9C and R ^10C each independently represent a hydrogen atom, an optionally substituted alkyl group, or an optionally substituted aryl group. ) 4. The thermal transfer ink according to claim 2, wherein the ring A of the arylidenepyrazolone dye represented by the general formula (I) has an alkyl group having 1 to 10 carbon atoms, which may be substituted, and a carbon number. A benzene ring optionally substituted with 1 to 10 substituents selected from the group consisting of an optionally substituted alkoxy group and a halogen atom,
R ¹ and R ² are each independently an optionally substituted alkyl group having 1 to 12 carbon atoms, an allyl group, an optionally substituted aryl group having 6 to 10 carbon atoms, or 5 to 7 carbon atoms. Is an optionally substituted cycloalkyl group,
R ³ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted,
An NR ⁹ R ¹⁰ group, an optionally substituted alkoxy group having 1 to 8 carbon atoms, an optionally substituted alkoxycarbonyl group having 2 to 9 carbon atoms, and an optionally substituted alkoxycarbonyl group having 6 to 10 carbon atoms An aryl group or a C (O) NR ^9A R ^10A group having 3 to 9 carbon atoms,
R ⁴ is an optionally substituted alkyl group having 1 to 12 carbon atoms, or thermal transfer recording ink, characterized in that at the optionally substituted aryl group having 6 to 10 carbon atoms. ^{5. The} thermal transfer ink according to claim 3, wherein R ⁵ and R ⁶ of the bispyrazolone methine dye represented by the general formula (II) each independently have 1 to 10 carbon atoms. A good alkyl group, an optionally substituted alkenyl group having 1 to 10 carbon atoms, or an optionally substituted aryl group having 6 to 10 carbon atoms,
R ⁷ and R ⁸ are each independently an optionally substituted alkyl group having 1 to ¹⁰ carbon atoms, an NR ^9B R ^10B group having 1 to 8 carbon atoms, and optionally substituted with 1 to 8 carbon atoms. An alkoxy group, an optionally substituted alkoxycarbonyl group having 2 to 9 carbon atoms, an optionally substituted aryl group having 6 to 10 carbon atoms, or a C (O) NR ^{9 C} R ^{10 C} group having 3 to 9 carbon atoms A thermal transfer recording ink, characterized in that: A thermal transfer recording sheet comprising a substrate and a coloring material layer containing a dye having an arylidenepyrazolone skeleton and a dye having a bispyrazolonemethine skeleton. 7. The thermal transfer recording sheet according to claim 6, wherein the dye having an arylidenepyrazolone skeleton is an arylidenepyrazolone-based dye represented by the following general formula (I).

(Wherein, ring A represents a benzene ring which may have an optional substituent,
R ¹ and R ² 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 ³ is a hydrogen atom, an optionally substituted alkyl group, an NR ⁹ R ¹⁰ group, an optionally substituted alkoxy group, an optionally substituted alkoxycarbonyl group, an optionally substituted aryl group, Or a C (O) NR ^9A R ^10A group,
R ⁴ represents an optionally substituted alkyl group or an optionally substituted aryl group.
R ⁹ , R ¹⁰ , R ^9A , and R ^10A each independently represent a hydrogen atom, an optionally substituted alkyl group, or an optionally substituted aryl group. ) The thermal transfer sheet according to claim 6, wherein the dye having a bispyrazolone methine skeleton is a bispyrazolone methine-based dye represented by the following general formula (II).

(Wherein, R ⁵ and R ⁶ each independently represent an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group;
R ⁷ and R ⁸ each independently represent an optionally substituted alkyl group, an NR ^9B R ^10B group,
Represents an optionally substituted alkoxy group, an optionally substituted alkoxycarbonyl group, an optionally substituted aryl group, or a C (O) NR ^{9 C} R ^{10 C} group.
R ^9B , R ^10B , R ^9C and R ^10C each independently represent a hydrogen atom, an optionally substituted alkyl group, or an optionally substituted aryl group. ) 9. The thermal transfer sheet according to claim 7, wherein the ring A of the arylidenepyrazolone dye represented by the general formula (I) has an alkyl group having 1 to 10 carbon atoms, which may be substituted, and a carbon number. A benzene ring optionally substituted with 1 to 10 substituents selected from the group consisting of an optionally substituted alkoxy group and a halogen atom,
R ¹ and R ² are each independently an optionally substituted alkyl group having 1 to 12 carbon atoms, an allyl group, an optionally substituted aryl group having 6 to 10 carbon atoms, or 5 to 7 carbon atoms. Is an optionally substituted cycloalkyl group,
R ³ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted,
An NR ⁹ R ¹⁰ group, an optionally substituted alkoxy group having 1 to 8 carbon atoms, an optionally substituted alkoxycarbonyl group having 2 to 9 carbon atoms, and an optionally substituted alkoxycarbonyl group having 6 to 10 carbon atoms An aryl group or a C (O) NR ^9A R ^10A group having 3 to 9 carbon atoms,
R < ⁴ > is a C1-C12 alkyl group which may be substituted, or a C6-C10 aryl group which may be substituted, The sheet for thermal transfer recording characterized by the above-mentioned. 10. The thermal transfer sheet according to claim 8, wherein R ⁵ and R ⁶ of the bispyrazolone methine dye represented by the general formula (II) are each independently substituted with 1 to 10 carbon atoms. A good alkyl group, an optionally substituted alkenyl group having 1 to 10 carbon atoms, or an optionally substituted aryl group having 6 to 10 carbon atoms,
R ⁷ and R ⁸ are each independently an optionally substituted alkyl group having 1 to ¹⁰ carbon atoms, an NR ^9B R ^10B group having 1 to 8 carbon atoms, and optionally substituted with 1 to 8 carbon atoms. An alkoxy group, an optionally substituted alkoxycarbonyl group having 2 to 9 carbon atoms, an optionally substituted aryl group having 6 to 10 carbon atoms, or a C (O) NR ^{9 C} R ^{10 C} group having 3 to 9 carbon atoms A thermal transfer recording sheet, characterized in that: A method for performing thermal transfer recording using the thermal transfer sheet according to any one of claims 6 to 10, wherein the recorded image is set to a 2 degree viewing angle using a D50 light source. A * value in CIELAB space at a color density of 1.0 is -13 or more and 10 or less, and b * value is 60 or more in a thermal transfer recording method.