JP2009101702A - Thermosensitive transfer ink, thermosensitive transfer sheet, and thermosensitive transfer recording method using the sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide yellow ink for use in thermosensitive transfer which can exhibit clear and highly dense yellow with low energy, can obtain a thermosensitive transfer record excellent in color tone and light resistance, and can exhibit a highly dense preferable green tone even if mixed with cyan, and to provide a thermosensitive transfer sheet. <P>SOLUTION: The thermosensitive transfer ink includes: a pigment having an allylidene pyrazolone skeleton; a pigment having a bispyrazolone methine skeleton; and a medium. In addition, the thermosensitive transfer sheet includes a color material layer which includes: a pigment having an allylidene pyrazolone skeleton and a pigment having a bispyrazolone methine skeleton on a base material. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  In dye transfer type thermal transfer recording, a thermal transfer sheet having a colorant layer containing a heat transferable dye on a base film and an image receiving sheet having a dye receiving layer on the surface are superposed to heat the thermal transfer sheet. Is a recording method in which recording is performed by transferring the dye in the thermal transfer sheet to the 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 transfer amount of the dye according to the amount of heating energy.

In such a dye transfer type thermal transfer recording, the dye used in the transfer sheet and the ink composition for the transfer sheet has a great influence on the speed of transfer recording, the image quality of the recorded matter, storage stability, etc. The characteristics of this dye are very important, and such a dye must satisfy the following conditions.
1) Easy sublimation and / or thermal diffusion under the operating conditions of the thermal recording head.

2) Do not thermally decompose under the operating conditions of the thermal recording head.
3) It has a favorable hue for color reproduction.
4) Large molecular extinction coefficient.
5) Stable against heat, light, moisture and chemicals.
6) Easy to synthesize.

7) Excellent inkability.
8) There are no safety issues.
Conventionally, among the dyes used in such thermal transfer recording, it is known to use an arylidene pyrazolone dye represented by the general formula (I) as a dye for sublimation thermal transfer recording ( For example, see Patent Documents 1 to 3). In addition, a combination system of an arylidene pyrazolone dye and a specific dicyanomethine yellow dye and a combination system of an arylidene pyrazolone dye and a specific pyridone azo yellow dye are also 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 A combination system of bispyrazolone methine dye and a specific pyridoneazo yellow dye, a combination system of bispyrazolone methine dye and a specific quinophthalone yellow dye, and a specific dye including a bispyrazolone methine dye Three types of combination systems are described (for example, see Patent Documents 4 to 7).

JP-A-2-3450 Japanese Patent Laid-Open No. 4-265922 JP-A-4-275184 Japanese Patent Laid-Open No. 10-864 Japanese Patent Laid-Open No. 10-181224 Japanese Patent Laid-Open No. 10-203029 JP 2000-103174 A

  However, with any of the above prior arts, a sufficiently disclosed dye or dye mixture has not yet been able to obtain sufficient performance as shown in Comparative Examples described later. Therefore, development of thermal transfer recording inks and sheets having high recording density, clear color tone of recorded matter, high stability of recorded matter, and excellent overall properties as a yellow dye for thermal transfer recording is desired. It was rare.

  The present invention has comprehensively excellent performance in all the properties 1) to 8) required for the dye for thermal transfer recording, in particular, the recording density is high, and the color tone of the recorded matter is clear. It is an object of the present invention to provide a thermal transfer ink, a thermal transfer sheet, and a thermal transfer recording method with high stability of the recorded matter.

The thermal transfer ink of the present invention is characterized by containing a dye having an arylidene pyrazolone skeleton, a dye having a bispyrazolone methine skeleton, and a medium.
The heat-sensitive transfer recording sheet of the present invention is characterized by having a coloring material layer containing a dye having an arylidene pyrazolone skeleton, a dye having a bispyrazolone methine 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 at a viewing angle of 2 degrees using a D50 light source. In this case, the a * value in the CIELAB space at a color density of 1.0 is −13 to 10, and the b * value is 60 or more.
That is, the present inventors have conducted detailed studies on the yellow dye mixture for thermal transfer recording in order to achieve the above object, and as a result, the following (A) dye having an arylidenepyrazolone methine skeleton and the following (B) bis By using in combination with a dye having a pyrazolone methine skeleton, it is possible to obtain a recorded material having a high recording density, a clear color tone of the recorded material, and a high stability of the recorded material, as compared with the conventional product. We have found out that we can do it and have reached the present invention.

In the above formula, the dotted line represents unsubstituted or has an arbitrary substituent.
That is, the above-mentioned dye having an arylidenepyrazolone skeleton is highly sensitive in thermal transfer recording, but it is reddish as a yellow dye and is insufficient in terms of color tone. By combining such a dye having an arylidene pyrazolone skeleton with a dye having a bispyrazolone methine 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, and thus the redness of the dye having the arylidenepyrazolone skeleton can be suppressed, and sensitivity and light resistance can be maintained. Is.

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 a dye having a maximum absorption wavelength (λmax) corresponding to 350 to 480 nm can be suitably obtained. .

According to the present invention, all the characteristics required for thermal transfer recording dyes are comprehensively excellent, and the sensitivity is high, the recording density is high, the color tone of the recorded matter is clear, and the recorded matter is stable. Highly sensitive thermal transfer recording dye, thermal transfer recording ink, thermal transfer recording sheet and thermal transfer recording method using the same are provided.
In particular, according to the present invention, it is possible to obtain a heat-sensitive transfer recording material that exhibits a clear yellow color with a low energy and a high density, a color tone that is preferable as a yellow color, and a remarkably good light resistance. A green color tone having a preferable color tone can be obtained at a high density, and the light resistance of the obtained recorded matter is very good.

Hereinafter, embodiments of the present invention will be described in detail.
First, a dye having an arylidene pyrazolone skeleton and a dye having a bispyrazolone methine skeleton used in the present invention will be described.
In addition, below, when the said group has a substituent, the suitable carbon number of the illustrated group shows the total carbon number including the carbon number of the substituent.

  The dye having an arylidene pyrazolone skeleton used in the present invention is preferably an arylidene pyrazolone dye represented by the following general formula (I). In addition, in the following general formula (I), 1-4 show the position of the substituent of the ring A.

  In general formula (I), ring A is an optionally substituted benzene ring, preferably an optionally substituted alkyl group having 1 to 10 carbon atoms, and a substituted group 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 is 1 to 4 (1 to 4 The position 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, it may be a C1-C12 optionally substituted alkyl group, an allyl group, a C6-C10 substituted aryl group, or a C5-C7 substituted. 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 optionally substituted alkyl group having 1 to ¹⁰ carbon atoms, an NR ⁹ R ¹⁰ group having 1 to 8 carbon atoms, or a carbon number. 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 optionally substituted alkyl group or an optionally substituted aryl group, and among them, preferably an alkyl group having 1 to 12 carbon atoms which may be substituted, or 6 carbon atoms. It is an aryl group which may have 10 to 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, preferably hydrogen. 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 chain having 1 to 4 carbon atoms. And 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, and R ⁴ is preferably phenonyl. A phenyl group having a halogen atom as a group or substituent 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 general formula (II), R ⁵ and R ⁶ each independently represent an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group, of which 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 are each independently an optionally substituted alkyl group, an NR ^9B R ^10B group, an optionally substituted alkoxy group, an optionally substituted alkoxycarbonyl group, or an optionally substituted Represents a good aryl group or a C (O) NR ^9C R ^10C group, preferably an alkyl group having 1 to 10 carbon atoms which may be substituted, an NR ^9B R ^10B group having 1 to 8 carbon atoms, carbon 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 3 carbon atoms 9 C (O) NR ^9C R ^10C groups.

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, preferably hydrogen 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 are each independently a linear or branched alkyl group having 1 to 8 carbon atoms, or 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 these, 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. Yuru C.I. I. It is 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 as the substituent of ring A have 1 carbon atom. -12, preferably a linear or branched alkyl group having 1 to 10 carbon atoms, specifically, methyl group, ethyl group, n-propyl group, i-propyl group, 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 examples thereof include the following.
Alkoxy group-substituted alkyl groups such as 2-ethoxyethyl group, 2-n-propoxyethyl group, 2-n-butoxyethyl group, 4-i-propoxybutyl group, 3-i-butoxypropyl group; 2-chloroethyl group, Halogen atom substituted alkyl groups such as 4-chlorobutyl group and trifluoromethyl group; Cyano group substituted alkyl groups such as cyanoethyl group; Aryl group substituted alkyl groups such as benzyl group, 2-phenylethyl group and p-chlorobenzyl group; Phenoxy Aryloxy-substituted alkyl groups such as methyl, 2-phenoxyethyl and 4-phenoxybutyl; alkoxycarbonyl such as 2-methoxycarbonylethyl, 3-n-butoxycarbonylpropyl and 2-allyloxycarbonylethyl Group-substituted or allyloxycarbonyl group-substituted alkyl group; 2 Aryloxycarbonyl group-substituted alkyl groups such as phenoxycarbonylethyl group and 4-p-chlorophenoxycarbonylbutyl group; aralkyloxy group-substituted alkyl groups such as 2-benzyloxyethyl group and 4-benzyloxybutyl group; 2-acetoxyethyl Group, acyloxy group-substituted alkyl groups such as 2-benzoyloxyethyl group and 4-acetoxybutyl group.

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

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

When the alkoxy 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 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, and an i-butyloxycarbonyl group. , T-butyloxycarbonyl group, n-hexyloxycarbonyl group, n-octyloxycarbonyl group, 2-ethylhexyloxycarbonyl group and the like, C2-C12, preferably C2-C8 alkoxycarbonyl groups. .

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 skeleton structure is used in combination, the effects of the present invention can be obtained, but in order to fully express the effects of the present invention by these combinations, the skeleton portion and other A dye having an arylidene pyrazolone skeleton including a partial structure usually has a molecular weight of 600 or less, particularly 500 or less, particularly 240 to 500, and a dye having a bispyrazolone methine skeleton usually has a molecular weight of 600 or less. In particular, it is preferably 500 or less, particularly preferably in the range of 200 to 500.

  Although the specific example of the pigment | dye represented by the said general formula (I) and (II) is illustrated in following Table 1 and 2, respectively, it is not limited to these at all. These dyes can be produced, for example, according to the methods described in JP-A-2-3450, JP-A-49-114420 and the like.

  In the thermal transfer recording ink and the thermal transfer recording sheet of the present invention, the ratio of the dye having an arylidene pyrazolone skeleton to the dye having a bispyrazolone methine skeleton is a dye having an arylidene pyrazolone skeleton: a bispyrazolone methine skeleton. Pigment = 1: 9 to 9: 1 (weight ratio), particularly 2: 8 to 8: 2, particularly 3: 7 to 7: 3. Even if there are more or less dyes having an arylidene pyrazolone skeleton exceeding the above range, the effect of the present invention by using in combination with a dye having a bispyrazolone methine skeleton cannot be sufficiently obtained.

  Although it can be used in combination with other yellow dyes as long as the effects of the present invention are not impaired, the content of the other yellow dyes is usually as follows: the dye having the arylidene pyrazolone 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, and particularly preferably 5 parts by weight with respect to the total amount of dye having a skeleton as 100 parts by weight. Less than parts by weight.

SWOP (Specifications Web Offset publications)
In order to achieve this, the ratio may be selected as appropriate within the above range. For example, it is preferable that the pigment having an arylidenepyrazolone skeleton: the pigment having a bispyrazolone methine skeleton = 3: 7 to 5: 5 (weight ratio). .
The thermal transfer ink of the present invention is obtained by dissolving or dispersing a dye having an arylidenepyrazolone skeleton of the present invention 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, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and other ketones, methylene chloride, chloroform, trichloroethylene and other chlorinated solvents, tetrahydrofuran, dioxane and other ethers, N, N-dimethylformamide, N-methylpyrrolidone, etc. These organic solvents may be used, and these may be used alone or in combination of two or more.

In the ink of the present invention, in addition to the dye and the medium, organic and inorganic non-sublimable fine particles, a dispersant, an antistatic agent, an antifoaming agent, an antioxidant, a viscosity adjusting agent and the like are added as necessary. An agent 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, and particularly 2 to 15 parts by weight in 100 parts by weight of the ink. Further, the ratio of the above additives other than the pigment is 5 parts by weight or less, particularly 3 parts by weight or less in 100 parts by weight of the ink, and the lower limit when adding these additives is 0.01. It is preferably at least 0.5 part by weight, particularly at least 0.5 part by weight.

  The thermal transfer sheet of the present invention has a color material layer containing a pigment having an arylidene pyrazolone skeleton and a pigment having a bispyrazolone methine skeleton on a substrate. The colorant layer may contain a yellow dye having a different structure other than a dye having an arylidene pyrazolone skeleton and a dye having a bispyrazolone methine skeleton, as long as the effects of the present invention are not hindered.

The method for forming the color material layer on the substrate is not particularly limited, but usually, an ink is prepared by dissolving the pigment together with the binder in the above-mentioned medium or dispersing it in the form of fine particles. A method of coating and drying on top is employed.
Examples of the binder used here include water-soluble resins such as cellulose, acrylic acid, starch, and epoxy, acrylic resin, methacrylic resin, polystyrene, polycarbonate, polyethersulfone, polyvinyl butyral, and ethylcellulose. Resins soluble in organic solvents such as acetylcellulose, polyester, AS resin, and phenoxy resin can be mentioned, and the ratio of the binder to the dye in the thermal transfer ink for forming the colorant layer is usually binding. The range of agent: dye = 1: 2 to 2: 1 (weight ratio) is appropriate. In addition, about a binder, you may use individually by 1 type, and may mix and use 2 or more types.

The base film that is the base material on which the ink for transfer sheet creation is applied includes thin paper such as condenser paper and glassine paper, and plastic films with good heat resistance such as polyester, polycarbonate, polyamide, polyimide, and polyaramid. The thickness is usually in the range of 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 necessarily have sufficient heat resistance, and the running performance of the thermal head is insufficient, so that the surface opposite to the surface on which the color material layer is formed has a high lubricant and lubricity. By providing a heat-resistant resin layer containing heat-resistant fine particles, a surfactant, a binder and the like, it is possible to use a thermal head with improved running performance. In this case, examples of the lubricant include modified silicone compounds such as amino-modified silicone compounds and carboxy-modified silicone compounds, the heat-resistant fine particles include fine particles such as silica, and the binder includes an acrylic resin. . The thickness of this heat resistant resin layer is usually preferably in the range of 0.1 to 50 μm.

Application of the ink to the base film can be performed using a gravure coater, reverse roll coater, rod coater, air doctor coater, etc., and the ink has a thickness after drying of the color material layer of 0.1 to 10. It is preferable to apply in a range of 5 μm.
The heat-sensitive transfer sheet of the present invention can utilize not only a thermal head but also infrared rays, laser light, and the like as heating means. Moreover, it can also be used as an energization type dye transfer sheet using an energization heat generating film that generates heat when electricity is applied to the base film itself.

In thermal transfer recording, color printing is usually performed by repeating the thermal recording operation for transfer sheets of three colors of yellow, magenta and cyan, or four colors including black. The hue of the obtained image is expressed by L ^* value, a ^* value, and 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 that is preferable as a hue of yellow, that is, an a ^* value at a color density of 1.0 when set to a viewing angle of 2 degrees using a D50 light source, It is possible to achieve those having −13 or more and 10 or less, particularly −13 or more and 5 or less, and b ^* value of 60 or more, preferably 65 or more, particularly 70 or more. This range also includes the color reference SWOP (Specifications Web Offset Publications) for color proof ink used in the printing industry.

Further, the transfer density is also excellent. For example, the color density when recorded by the method of the present embodiment is usually 1.8 or more, preferably 2.0 or more.
Further, a yellow recorded image (color density of about 1.0) using the ink of the present invention was obtained by using a xenon weatherometer Ci4000 (manufactured by Atlas Co., Ltd.). The degree of color fading {ΔE (L *, a *, b *)} of the recorded matter after the property test is 10 or less, preferably 5 or less. Shows the results of a light fastness test {ΔE (L *) of a green color recording image (color density of about 1.0) using an indoaniline dye represented by the structural formula (III) used in the following examples. , A *, b *)} is also 20 or less
Preferably, it has excellent light resistance even when a color mixture of 15 or less and a cyan dye is used.

  The thermal transfer ink and thermal transfer sheet of the present invention have a high recording density for thermal transfer recording, a clear color tone of the recorded matter, and a high stability of the recorded matter, particularly excellent in light resistance of the recorded matter. In addition, since the pigment can be easily produced, it can be produced industrially advantageously.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.
Example 1
Ink (Y) and ink (C) were prepared by treating a mixture having the following composition with an ultrasonic cleaner for 30 minutes.

[Formulation of ink (Y) (parts by weight)]
No. 1-1 Dye: 3.0
No. 2-1 dye: 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 obtained inks (Y) and (C) were each coated on a polyethylene terephthalate film (6 μm thickness) using a wire bar and dried (dry film thickness of about 1 μm) to form a color material layer, and then this polyethylene terephthalate film 10 parts by weight of 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 weights of toluene A heat-resistant resin layer was formed by applying and drying the liquid composed of the parts (dry film thickness of about 1 μm) to obtain a heat-sensitive transfer sheet (Y) and a heat-sensitive transfer sheet (C).

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

The color density, CIELAB a ^* value, and b ^* value were measured using a spectrocolorimeter (trade name: SPM-50, manufactured by Gretag).
The transfer sheets (Y) and (C) were transferred and recorded in this order on the same receiver under the same recording conditions as described above to obtain a green color recorded matter.
Further, a light resistance test of the obtained yellow color record and green color record (with a color density of about 1.0) was performed using a xenon weatherometer Ci4000 (manufactured by Atlas) (black panel temperature: 58 ± 3 ° C.) The degree of color fading {ΔE (L *, a *, b *)} after 40 hours of irradiation is shown in Table 3.

Examples 2-3
In Example 1, ink preparation, thermal transfer sheet preparation, transfer recording, and light resistance test were conducted in the same manner except that the yellow dyes shown in Table 3 were used. The results are shown in Table 4. .
Comparative Examples 1-9
In Example 1, ink preparation, thermal transfer sheet preparation, transfer recording, and light resistance test were conducted in the same manner except that the yellow dyes shown in Table 3 were used. The results are shown in Table 4. . Here, the structures of the dye A to the dye 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 2000-103174 A)

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

No. 2 in Comparative Example 2 The dye 1-2 is No. 1 described in JP-A-2-3450. No. 1 of Comparative Example 3 The dye of 2-1 is a dye used in Example 1 described in JP-A-10-864 (CI Solvent Yellow).
93).
Comparative Example 4 corresponds to the combination of dyes used in the examples described in JP-A-4-2657892 and Comparative Example 5 corresponds to the combination of dyes used in the 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 is used in Example 1 described in JP-A-10-181224. Comparative Example 8 corresponds to the combination of the dyes used in Example 1 of JP-A-10-203029, and Comparative Example 9 is the implementation of JP-A-2000-103174. This corresponds to the combination of dyes used in Example 1.

As is clear from the comparison of the above-mentioned examples and comparative examples, according to the present invention, it is clear that a recorded matter having an excellent transfer density can be obtained by balancing the a ^* value and the b ^* value.
Example 4
Using the ink prepared by the following method instead of the ink used in Example 1, a transfer sheet was prepared, transferred and evaluated by the same method as in Example 1. As a result, a record having a uniform color density was obtained. In addition, it was confirmed that the obtained recorded matter had good light resistance.

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

Claims (9)

A thermal transfer ink comprising: a dye having an arylidene pyrazolone skeleton represented by the following general formula (I); a dye having a bispyrazolone methine skeleton; and a medium.

(In the formula, ring A represents an optionally substituted benzene ring,
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 represents an NR ⁹ R ¹⁰ group or an optionally substituted alkoxy group,
R ⁴ represents an alkyl group which may be substituted or an aryl group which may be substituted.
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. ) 2. 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 represents an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group;
R ⁷ and R ⁸ are each independently an optionally substituted alkyl group, an NR ^9B R ^10B group, an optionally substituted alkoxy group, an optionally substituted alkoxycarbonyl group, or an optionally substituted Represents a good aryl group or a C (O) NR ^9C R ^10C 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. ) The thermal transfer ink according to claim 1 or 2, wherein the ring A of the arylidenepyrazolone dye represented by the general formula (I) is an alkyl group having 1 to 10 carbon atoms and an optionally substituted carbon group. A benzene ring which may be substituted with a substituent selected from the group consisting of 1 to 10 optionally substituted alkoxy groups and halogen atoms;
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. An optionally substituted cycloalkyl group,
R ³ is an NR ⁹ R ¹⁰ group having 1 to 8 carbon atoms or an optionally substituted alkoxy group having 1 to 8 carbon atoms,
An ink for thermal transfer recording, wherein R ⁴ is an optionally substituted alkyl group having 1 to 12 carbon atoms or an optionally substituted aryl group having 6 to 10 carbon atoms. The thermal transfer ink according to claim 2 or 3, 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, or an optionally substituted group having 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 ^9C R ^10C group having 3 to 9 carbon atoms A thermal transfer recording ink characterized by A heat-sensitive transfer sheet comprising a colorant layer comprising a dye having an arylidenepyrazolone skeleton represented by the following general formula (I) and a dye having a bispyrazolone methine skeleton on a substrate.

(In the formula, ring A represents an optionally substituted benzene ring,
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 represents an NR ⁹ R ¹⁰ group or an optionally substituted alkoxy 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. ) 6. The thermal transfer sheet according to claim 5, 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 represents an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group;
R ⁷ and R ⁸ are each independently an optionally substituted alkyl group, an NR ^9B R ^10B group, an optionally substituted alkoxy group, an optionally substituted alkoxycarbonyl group, or an optionally substituted Represents a good aryl group or a C (O) NR ^9C R ^10C 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. ) The thermal transfer sheet according to claim 5 or 6, wherein the ring A of the arylidenepyrazolone dye represented by the general formula (I) is an alkyl group having 1 to 10 carbon atoms which may be substituted, or a carbon number. A benzene ring which may be substituted with a substituent selected from the group consisting of 1 to 10 optionally substituted alkoxy groups and halogen atoms;
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. An optionally substituted cycloalkyl group,
R ³ is an NR ⁹ R ¹⁰ group having 1 to 8 carbon atoms or an optionally substituted alkoxy group having 1 to 8 carbon atoms,
R ⁴ is an optionally substituted alkyl group having 1 to 12 carbon atoms or an optionally substituted aryl group having 6 to 10 carbon atoms. The thermal transfer sheet according to claim 6 or 7, 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, or an optionally substituted group having 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 ^9C R ^10C group having 3 to 9 carbon atoms A thermal transfer recording sheet characterized by the above.   A method for performing thermal transfer recording using the thermal transfer sheet according to any one of claims 5 to 8, wherein the recorded image is set at a viewing angle of 2 degrees using a D50 light source. A thermal transfer recording method, wherein the a * value in the CIELAB space at a color density of 1.0 is from -13 to 10 and the b * value is 60 or more.