JP2006044253A - Thermal transfer recording material and thermal transfer recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal transfer recording material for obtaining an image which is excellent in sensitivity, fixing property and image retention quality, and to provide a thermal transfer recording method using the recording material. <P>SOLUTION: The thermal transfer recording material contains coloring matter having a pyrazolopyrimidine-7 one parent nucleus having a specific structure. Further, an image receiving material having a coloring matter image receiving layer containing a metallic ion on base material is superimposed on the thermal transfer recording material. The thermal transfer recording material is heated according to image information, and a metal chelate coloring matter image is formed by reaction of the coloring matter and the metallic ion contained compound to feature the thermal transfer recording method. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermal transfer recording material and a thermal transfer recording method.

  Conventionally, as a method for obtaining a color hard copy, color image recording using an ink jet, electrophotography, thermal transfer, silver halide photosensitive material or the like has been studied. Among these, image recording using a thermal transfer recording material has advantages such as easy operation and maintenance, downsizing and cost reduction of the apparatus, and low running cost. .

  In image recording using this thermal transfer recording material, the dye used for the thermal transfer recording material (hereinafter also referred to as thermal transfer material) is important. For the purpose of improving the stability of the obtained image, particularly fixing and light resistance, a heat-sensitive transfer material using a chelatable heat-diffusible dye (hereinafter referred to as post-chelate dye) and an image forming method, ie, a light-sensitive material. Thermal transfer recording methods have been proposed, and are described in Patent Documents 1 to 3, for example. The images formed using the post-chelating dyes disclosed in Patent Documents 1 to 3 are excellent in light resistance and fixability, but are sufficiently satisfactory in terms of the sensitivity of the thermal transfer material and the storage stability of the material itself. In addition, since the hue difference between the chelate dye and the chelate dye is large, if the chelate reaction during image formation is insufficient, absorption of unreacted chelate dye remains or forms. In other words, when a full-color image is obtained, it is necessary to further improve the color reproduction.

  Therefore, Patent Documents 4 to 7 propose thermal transfer recording materials using a dye having a pyrazolopyrimidin-7-one mother nucleus. Although these dyes have improved the above-mentioned problems to some extent, they cannot be said to be yet a sufficient level, and particularly, storage stability under high temperature and high humidity (heat resistance humidity resistance) and storage stability under light irradiation. (Light resistance) is insufficient, and further improvement has been desired.

Furthermore, in recent years, it has been regarded as important to express shading with lower energy in order to cope with the speeding up of image printing. In other words, as far as dyes are concerned, so-called highly sensitive dyes with high thermal response are desired. However, including the balance with preservability, the above dyes are still not at a sufficient level.
JP 59-78893 JP 59-109349 A JP-A-60-2398 JP-A-3-143684 JP-A-3-143686 Japanese Patent Application No. 9-257947 Japanese Patent Application No.11-60123

  In view of the above problems, an object of the present invention is to provide a thermal transfer recording material for obtaining an image excellent in sensitivity, fixability, and image storage stability, and a thermal transfer recording method using the recording material. .

  As a result of intensive studies, the present inventors have found that the above problems can be solved by using a novel dye having a pyrazolopyrimidin-7-one mother nucleus.

That is, the said subject of this invention is achieved by the following structure.
1. A thermal transfer recording material comprising at least one dye represented by the following general formula (II).

[Wherein, R ₂₁ and R ₂₂ each represent a substituted or unsubstituted aliphatic group, and R ₂₃ represents a substituent. n represents an integer of 0 to 4, and when n is 2 or more, the plurality of R ₂₃ may be the same or different. R ₂₅ and R ₂₆ represent an alkyl group. However, at least one of R ₂₅ and R ₂₆ represents a secondary alkyl group. ]

2. 2. The thermal transfer recording material according to 1 above, wherein the dye of the general formula (II) is represented by the following general formula (III), (IV) or (V).

[In Formula (III), R ₃₁ and R ₃₂ each represent a substituted or unsubstituted aliphatic group, and R ₃₃ represents a substituent. n represents an integer of 0 to 4, and when n is 2 or more, the plurality of R ₃₃ may be the same or different. ]

[In Formula (IV), R ₄₁ and R ₄₂ each represent a substituted or unsubstituted aliphatic group, and R ₄₃ represents a substituent. n represents an integer of 0 to 4, and when n is 2 or more, the plurality of R ₄₃ may be the same or different. ]

[In Formula (V), R ₅₁ and R ₅₂ each represent a substituted or unsubstituted aliphatic group, and R ₅₃ represents a substituent. n represents an integer of 0 to 4, and when n is 2 or more, the plurality of R ₅₃ may be the same or different. ]

3. 3. The thermal transfer recording material according to 1 or 2 above, wherein the dye represented by at least one of the general formulas (II) to (V) has a molecular weight of 300 to 410.

4). 4. The thermal transfer recording material as described in 2 or 3 above, wherein the dye represented by the general formula (IV) is the following structural formula (1).

5. An image receiving material is superimposed on a thermal transfer recording material having a dye-donating layer containing at least one of the dyes represented by the general formulas (II) to (V) or the structural formula (1) on a support. A thermal transfer recording method, wherein the thermal transfer recording material is heated in accordance with image information to form an image.

6). On a support, a thermal transfer recording material having a dye-donating layer containing at least one of the dyes represented by the general formulas (II) to (V) or the structural formula (1) on the support. An image receiving material having a dye image-receiving layer containing a metal ion-containing compound is superimposed on the heat-sensitive transfer recording material according to image information, and a metal chelate dye image is formed by the reaction between the dye and the metal ion-containing compound. And a thermal transfer recording method.

7). It contains at least one metal chelate dye produced by the reaction of at least one of the general formulas (II) to (V) or the dye represented by the structural formula (1) with a metal ion-containing compound. Thermal transfer recording material.

8). At least one metal chelate dye produced by reaction of at least one of the general formulas (II) to (V) or the dye represented by the structural formula (1) with a metal ion-containing compound is used. Thermal transfer recording method.

  According to the present invention, a thermal transfer recording material and an image receiving sheet having high image quality (improved image bleeding), high sensitivity, excellent storage stability and image storage stability (light resistance), and high image quality and excellent image storage stability. It was possible to provide a thermal transfer image forming method capable of obtaining an image having the same. In addition, according to the present invention, a chelate dye image having high sensitivity and excellent light, heat, and moisture fastness could be provided.

  According to the invention shown in claim 3 or 4, the effect of the present invention is particularly remarkable.

The present invention is described in detail below.
First, the compounds used in the present invention will be described in detail.

In the general formula (II), R ₂₁ and R ₂₂ represent a substituted or unsubstituted aliphatic group, and R ₂₁ and R ₂₂ may be the same or different. Examples of the aliphatic group include an alkyl group, a cycloalkyl group, an alkenyl group, and an alkynyl group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an i-propyl group, and the like. Examples of the group that can replace these alkyl groups include a linear or branched alkyl group (for example, a methyl group, Ethyl group, i-propyl group, t-butyl group, n-dodecyl group, 1-hexylnonyl group and the like), cycloalkyl group (for example, cyclopropyl group, cyclohexyl group, bicyclo [2.2.1] heptyl group, And adamantyl group, etc.), and alkenyl groups (eg 2-propylene group, oleyl group etc.), aryl groups (eg phenyl group, ortho-tolyl group, ortho-anisyl group, 1-naphthyl group, 9-anthranyl group etc.), Heterocyclic groups (for example, 2-tetrahydrofuryl group, 2-thiophenyl group, 4-imidazolyl group, 2-pyridyl group, etc.), Gen atom (for example, fluorine atom, chlorine atom, bromine atom), cyano group, nitro group, hydroxy group, carbonyl group (for example, alkylcarbonyl group such as acetyl group, trifluoroacetyl group, pivaloyl group, benzoyl group, pentafluorobenzoyl) Group, arylcarbonyl group such as 3,5-di-t-butyl-4-hydroxybenzoyl group), oxycarbonyl group (for example, alkoxycarbonyl group such as methoxycarbonyl group, cyclohexyloxycarbonyl group, n-dodecyloxycarbonyl group) Aryloxycarbonyl groups such as phenoxycarbonyl group, 2,4-di-t-amylphenoxycarbonyl group, 1-naphthyloxycarbonyl group, 2-pyridyloxycarbonyl group, 1-phenylpyrazolyl-5-oxycarbonyl group, etc. of Oxycyclic carbonyl group), carbamoyl group (for example, dimethylcarbamoyl group, alkylcarbamoyl group such as 4- (2,4-di-t-amylphenoxy) butylaminocarbonyl group, phenylcarbamoyl group, 1-naphthylcarbamoyl group, etc. Arylcarbamoyl group), alkoxy group (for example, methoxy group, 2-ethoxyethoxy group, etc.), aryloxy group (for example, phenoxy group, 2,4-di-t-amylphenoxy group, 4- (4-hydroxyphenylsulfonyl)) Phenoxy group etc.), heterocyclic oxy group (eg 4-pyridyloxy group, 2-hexahydropyranyloxy group etc.), carbonyloxy group (eg acetyloxy group, trifluoroacetyloxy group, pivaloyloxy group etc.) Group, benzoyloxy group, Aryl urethane groups such as n-fluorobenzoyloxy group), urethane groups (eg, alkyl urethane groups such as N, N-dimethylurethane group, aryl urethanes such as N-phenylurethane group, N- (p-cyanophenyl) urethane group) Group), a sulfonyloxy group (for example, an alkylsulfonyloxy group such as methanesulfonyloxy group, trifluoromethanesulfonyloxy group, n-dodecanesulfonyloxy group, arylsulfonyloxy group such as benzenesulfonyloxy group, p-toluenesulfonyloxy group) Amino groups (for example, alkylamino groups such as dimethylamino group, cyclohexylamino group, n-dodecylamino group, arylamino groups such as anilino group, pt-octylanilino group, etc.), sulfonylamino groups (for example, methanesulfonyl) amino , Alkylsulfonylamino groups such as heptafluoropropanesulfonylamino group and n-hexadecylsulfonylamino group, arylsulfonylamino groups such as p-toluenesulfonylamino group and pentafluorobenzenesulfonylamino), sulfamoylamino groups (for example, N , Alkylsulfamoylamino groups such as N-dimethylsulfamoylamino group, arylsulfamoylamino groups such as N-phenylsulfamoylamino group), acylamino groups (eg alkyl such as acetylamino group and myristoylamino group) Arylcarbonylamino group such as carbonylamino group, benzoylamino group), ureido group (for example, alkylureido group such as N, N-dimethylaminoureido group, N-phenylureido group, N- (p-cyanophenyl) ureido Arylsulfide groups such as methanesulfonyl group, alkylsulfonyl groups such as trifluoromethanesulfonyl group, and arylsulfonyl groups such as p-toluenesulfonyl group), sulfamoyl groups (such as dimethylsulfamoyl group, 4- (2,4-di-t-amylphenoxy) alkylsulfamoyl groups such as butylaminosulfonyl group, arylsulfamoyl groups such as phenylsulfamoyl group), alkylthio groups (for example, methylthio group, t-octylthio group, etc.) ), An arylthio group (for example, phenylthio group), and a heterocyclic thio group (for example, 1-phenyltetrazol-5-thio group, 5-methyl-1,3,4-oxadiazole-2-thio group). Can be mentioned.

  Examples of the cycloalkyl group and the alkenyl group are the same as the above substituents. Examples of the alkynyl group include 1-propyne, 2-butyne, 1-hexyne and the like.

It is also preferred that R ₂₁ and R _{22 form} a non-aromatic cyclic structure (eg, pyrrolidine ring, piperidine ring, morpholine ring).

R ₂₃ represents a substituent, and examples of the substituent include the examples of the substituent of R ₂₁ and R ₂₂ described above. Among the above substituents, an alkyl group, a cycloalkyl group, an alkoxy group, and an acylamino group are preferable. n represents an integer of 0 to 4, and when n is 2 or more, the plurality of R ₂₃ may be the same or different.

R ₂₅ and R ₂₆ represent an alkyl group, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an isopropyl group, Examples thereof include a sec-butyl group, a tert-butyl group, a 3-heptyl group, and a 2-ethylhexyl group. At least one of R25 and R26 represents a secondary alkyl group, and examples of the secondary alkyl group include isopropyl group, sec-butyl group, 3-heptyl group, and 2-ethylhexyl group. The most preferred substituent as the secondary alkyl group for R ₂₅ and R ₂₆ is an isopropyl group. The secondary alkyl group of R ₂₆ may be substituted, but is all substituted with a substituent consisting of a carbon atom and a hydrogen atom. They are not substituted with substituents containing other atoms. R ₂₅ and R ₂₆ may be the same or different.

In the general formulas (III) to (V), descriptions of R ₃₁ , R ₃₂ , R ₄₁ , R ₄₂ , R ₅₁ , R ₅₂ are the same as the descriptions of R ₂₁ , R _{22 in} the general formula (II). _Also, the description of _{R 33,} R 43, R ₅₃ has the same meaning as described _{R 23} in the general formula (II).

  In the dyes of the general formulas (II) to (V) or the structure (1), the dye transfer property is good for use in a so-called thermal transfer type image forming method in which the dye is transferred by heat to obtain an image. There must be. In general, the lower the molecular weight of the dye, the better the transferability of the dye. However, even if the molecular weight is too low, a failure such as bleeding with time has occurred. In the present invention, as a result of intensive studies, the inventors have found that there is an optimum value for the molecular weight of the dye. The molecular weight of the dye is preferably 300 to 410, and more preferably 320 to 400.

  Although the specific example of the pigment | dye represented by general formula (II)-(V) of this invention below and the corresponding table | surface of molecular weight are shown, this invention is not limited to these.

  The dyes of the general formulas (II) to (V) and the structural formula (1) used in the present invention can be synthesized using the method described in JP-A-2000-255171. For example, in the case of Exemplified Compound 47, it can be synthesized according to the following scheme.

Synthesis examples of the exemplary compounds of the present invention are shown below.
(Synthesis example)
Synthesis Example 1 (Synthesis of Exemplified Compound 47)
In a reaction vessel to which 46 g (0.4741 mol) of aminopyrazole (1), 75 g (0.4741 mol) of ketoester (2) and 10.8 g (0.05689 mol) of p-toluenesulfonic acid monohydrate were added. 230 ml of toluene was added, and the mixture was heated for 1.5 hours while distilling off the water, methanol and solvent produced in the reaction. When 150 ml of acetonitrile was added to the obtained oily product, crystals were precipitated, which was separated by filtration to obtain 50.1 g of a dye precursor (3).

  12 ml of ethyl acetate was added to 3.47 g (0.01693 mol) of the dye precursor (3), and 5.38 g (0.05076 mol) of sodium carbonate, 2.5 g of Trax K-40 (activator), and 1 ml of water Were sequentially added and stirred vigorously in a 45 ° C. water bath for 1 hour. A solution in which 4.64 g of aniline analog (4) was dissolved in 12 ml of water and a solution in which 10.3 g of sodium persulfate and 9.16 g of sodium carbonate were dissolved in 36 ml of water were alternately added little by little. After completion of the addition, stirring was continued for an hour at 45 ° C., and then the reaction solution was cooled. The precipitated crystals were separated to obtain 2.16 g of green crystals having the metallic luster of Exemplified Compound 47 (yield 33.6%).

  The structure was confirmed by NMR spectrum and mass spectrum. In the acetone solution of Exemplified Compound 47, λmax was 580 nm and molar extinction coefficient (ε) was 52300. Moreover, melting | fusing point was 201 degreeC.

Synthesis Example 2 (Synthesis of Exemplified Compound 49)
A dye precursor was synthesized in the same formulation as that of Exemplified Compound 47, and aniline analog (4) was reacted to obtain 4.49 g of Exemplified Compound 49 (yield 65.1%). In the acetone solution of Exemplified Compound 49, λmax was 580 nm, and the molar extinction coefficient (ε) was 48700. The melting point was 243 ° C.

Synthesis Example 3 (Synthesis of Structural Formula (1))
A dye precursor was synthesized in the same formulation as Example Compound 47, and reacted with aniline analog (4) to obtain 4.66 g of Structural Formula (1) (yield 72.5%). In the acetone solution of the structural formula (1), λmax was 580 nm, and the molar extinction coefficient (ε) was 49700. The melting point was 213 ° C.

Other exemplary compounds were synthesized in the same manner.
The synthesized compounds are shown in Table 2.

  Next, synthesis examples of metal chelate dyes represented by the general formulas (2) to (6) will be given.

Synthesis Example 10 (Synthesis of chelate dye (3) -5)
In 100 ml of methanol, 24.3 g (0.06402) of Exemplified Compound 47 and 29.5 g (0.03201 mol) of Metal-containing Compound VI-7 were added and refluxed for 2 hours with stirring. After cooling the reaction solution, the solvent was distilled off by concentration under reduced pressure. Diisopropyl ether was added to the resulting reaction mixture, and the precipitated crystals were separated by filtration to obtain 46.3 g (yield: 86.0%) of chelate dye (3) -5. Λmax of this dye in acetone was 620 nm, and the molar extinction coefficient (ε) was 61700.

Synthesis Example 11 (Synthesis of chelate dye (5) -5)
Except that 26.1 g (0.03201 mol) of Exemplified Compound 49 was used instead of Exemplified Compound 47 in Synthetic Example 7, the reaction and purification were carried out in the same manner as in Synthetic Example 7 to obtain Chelate Dye (5) -5 in 37 0.1 g (yield 66.7%) was obtained.

  Λmax of this dye in acetone was 621 nm, and the molar extinction coefficient (ε) was 58400.

Synthesis Example 12 (Synthesis of chelate dye (6) -1)
In 100 ml of methanol, 24.3 g (0.06402 mol) of the structural formula (1) and 17.3 g (0.03201 mol) of metal-containing compound VI-1 were added and refluxed for 2 hours with stirring. The reaction solution was cooled, and the precipitated solid was separated by filtration to obtain 40.5 g of crude crystals. This crude crystal was recrystallized from methanol to obtain 34.5 g (yield: 82.9%) of chelate dye (6) -1. Λmax of this dye in acetone was 620 nm, and the molar extinction coefficient (ε) was 60300.

Synthesis Example 13 (Synthesis of chelate dye (6) -2)
The chelating dye (6)-was prepared by reacting and purifying in the same manner as in Synthesis Example 9 except that 29.5 g (0.03201 mol) of VI-7 was used instead of the metal-containing compound VI-1 in Synthesis Example 12. 42.6 g (yield 79.1%) of 2 was obtained.

Λmax of this dye in acetone was 621 nm, and the molar extinction coefficient (ε) was 62100.
Other chelate dyes were synthesized in the same manner.
The synthesized compounds are shown in Table 3.

  Next, the thermal transfer material (hereinafter sometimes referred to as a thermal transfer sheet dye-providing material), the image receiving material (hereinafter sometimes referred to as an image receiving sheet) and the thermal transfer recording method of the present invention will be described.

(Support)
The support used for the thermal transfer sheet of the present invention is not particularly limited, and the same support as that used for the conventional thermal transfer sheet can be used without any particular limitation. Specific examples of preferred supports include glassine paper, condenser paper, thin paper such as paraffin paper, polyethylene terephthalate, polyphenylene sulfide, polyether ketone, polyethersulfone and other highly heat-resistant polyester, polypropylene, polycarbonate, cellulose acetate, Examples thereof include stretched or unstretched films of plastics such as polyethylene derivatives, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, polymethylpentene, and ionomer, and laminates of these materials.

  The thickness of the support can be appropriately selected depending on the material so that the strength, thermal conductivity, heat resistance and the like are appropriate, but usually a thickness of about 1 to 100 μm is preferably used. When the support as described above has poor adhesion to a dye-donating layer (hereinafter sometimes referred to as a heat-sensitive transfer layer, an ink layer or a dye layer) formed on this surface, the surface is treated with a primer or corona. It is preferable to perform the treatment.

(Dye layer)
In the present invention, as the heat diffusible dye to be contained in the dye layer provided on one surface of the support, a reactive dye can be used from the viewpoint of obtaining good image storage stability.

  In the present invention, as mentioned above, the reactive dye is a dye that forms an image by reacting the dye precursor contained on the dye layer side and the dye fixing body contained on the image receiving layer side by thermal transfer. Indicates. Specifically, known reactive dyes including those described above can be used. In the present invention, from the viewpoint of particularly excellent image storage stability, a post-chelate dye (a chelatable dye) and It is preferable to use a combination of metal sources.

  The post-chelate dye is not particularly limited as long as thermal transfer is possible, and various known compounds can be appropriately selected and used. Specifically, for example, JP-A-59-78893, JP-A-59-109349, JP-A-2-213303, JP-A-2-214719, JP-A-2-203742, JP-A-10-258580, Cyan dyes, magenta dyes, yellow dyes and the like described in Japanese Utility Model Publication No. 2000-1057 and Japanese Patent Application No. 2001-032618 can be used.

Particularly preferred post-chelate dyes used in the present invention are listed below. First, with respect to the yellow dye, the following Exemplified Compound Nos. (1) -1 to (1) -32 can be exemplified.

  Regarding magenta dyes, the following Exemplified Compound Nos. (2) -1 to (2) -38 can be exemplified.

  The cyan dye is a dye represented by the general formulas (II) to (V) and the structural formula (1).

The amount of the post-chelate dye that is a pigment used in the present invention is usually preferably 0.1 g to 20 g, more preferably 0.2 g to 5 g, based on 1 m ^{2 of the} solid content of the dye.

Furthermore, in the present invention, a chelate pigment can be added to the dye layer. A detailed description of the chelate dye will be described later. In this case, there is no particular limitation on the amount of post chelate dye used in the present invention, usually, with respect to dye solids 1 m ^2, preferably 0.1G～20g, further 0.2g~5g is more preferable.

  The chelate dye used in the heat-sensitive transfer recording material of the present invention is not particularly limited, and examples thereof include compounds represented by at least one of the following general formulas (2) to (6). The compound has the structure shown in 74617.

  Particularly for cyan dyes, it is most preferable to use the compound of the present invention.

In the general formulas (2) to (6), the substituents R ₃₁ , R ₃₂ , R ₃₃ , R ₄₁ , R ₄₂ , R ₄₃ , R ₅₁ , R ₅₂ , R ₅₃ are the same as those in the general formula (II) and the general formula (II). It is synonymous with the description of III)-(V).

M ²⁺ represents a divalent metal ion, and among these, nickel and zinc are preferred from the color of the metal-containing compound itself and the color tone of the chelated dye. X represents a compound represented by the following general formula (VII) capable of forming a complex with a divalent metal ion.

  Specific examples of chelate dyes represented by general formulas (2) to (6) are shown below. The present invention is not limited to these.

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

In order to improve the releasability between the dye layer and the dye image-receiving layer (hereinafter sometimes referred to as a dye image-receiving layer), a release agent is added or a separate release layer containing a release agent ( Hereinafter, a non-transferable release layer may be provided. As the release agent, reactive curable silicones, phosphate ester surfactants, fluorine compounds, and the like can be used. As for the usage-amount of a mold release agent, 0.5-40 mass% is preferable with respect to solid content of the layer to contain. When providing a release layer, the same binder as that used for the dye layer can be used.
(Back layer: also called BC layer, back coat layer, back coat layer, anti-sticking layer, etc.)
It is also preferable to provide a back layer for imparting heat resistance to the surface of the support opposite to the surface on which the dye layer is provided.
(Protective layer)
In the thermal transfer recording of the present invention, a transparent protective layer formed by thermal transfer can be provided on the surface of the recording medium after dye transfer.

  The protective layer used in the present invention can also be provided in the so-called surface sequential manner on the same surface as the dye layer. On the other hand, when the protective layer is used alone as a protective layer transfer sheet, the same support and back layer as those described above can be used.

In the present invention, the thermal transferable protective layer is preferably provided on the support via a non-transferable release layer.
The non-transferable release layer may be provided via the primer layer or the like or may not be provided.

  The non-transfer release layer always has an adhesive force between the support and the non-transfer release layer that is greater than the adhesive force between the non-transfer release layer and the thermal transfer protective layer (protective transfer layer). (1) Resin binder for the purpose of increasing the adhesive strength between the non-transferable release layer and the heat transferable protective layer before application of heat to a sufficiently high level relative to that after application of heat. In addition, it contains 30 to 80% by mass of inorganic fine particles having an average particle size of 40 nm or less, or (2) a proportion of a total of 20% by mass or more of an alkyl vinyl ether / maleic anhydride copolymer, a derivative thereof, or a mixture thereof. Or (3) containing an ionomer in a proportion of 20% by mass or more. The non-transferable release layer may contain other additives as necessary.

  Examples of the inorganic fine particles include silica fine particles such as anhydrous silica and colloidal silica, and metal oxides such as tin oxide, zinc oxide, and zinc antimonate. The particle diameter of the inorganic fine particles is preferably 40 nm or less. If it exceeds 40 nm, the unevenness on the surface of the heat transferable protective layer is increased due to the unevenness on the surface of the release layer, and as a result, the transparency of the protective layer is lowered, which is not preferable.

  The resin binder to be mixed with the inorganic fine particles is not particularly limited, and any resin that can be mixed can be used. For example, polyvinyl alcohol resins (PVA) of various saponification degrees; polyvinyl acetal resins; polyvinyl butyral resins; acrylic resins; polyamide resins; cellulose resins such as cellulose acetate, alkyl cellulose, carboxymethyl cellulose, hydroxyalkyl cellulose; Examples thereof include resins.

  The blending ratio (inorganic particulate / other blending components) of the inorganic particulates and other blending components mainly composed of a resin binder is preferably in the range of 30/70 to 80/20 by weight. When the blending ratio is less than 30/70, the effect of the inorganic fine particles becomes insufficient. On the other hand, when the blending ratio exceeds 80/20, the release layer does not become a complete film, and the support and the heat transferable protective layer are in direct contact with each other. End up.

  Examples of the alkyl vinyl ether / maleic anhydride copolymer or derivative thereof described in (2) above include those in which the alkyl group of the alkyl vinyl ether portion is a methyl group or an ethyl group, and the maleic anhydride portion is partially or completely In addition, a half ester with alcohol (for example, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, etc.) can be used.

  The release layer may be formed only with an alkyl vinyl ether / maleic anhydride copolymer, a derivative thereof, or a mixture thereof, but for the purpose of adjusting the peeling force between the release layer and the protective layer, A resin or fine particles may be further added. In that case, the release layer preferably contains 20% by mass or more of an alkyl vinyl ether / maleic anhydride copolymer, a derivative thereof, or a mixture thereof. When the content is less than 20% by mass, the effect of the alkyl vinyl ether / maleic anhydride copolymer or its derivative cannot be sufficiently obtained.

  The resin or fine particles blended in the alkyl vinyl ether / maleic anhydride copolymer or its derivative is not particularly limited as long as it can be mixed and can provide high film transparency at the time of film formation, and any material can be used. I can do it. For example, the above-mentioned inorganic fine particles and resin binders that can be mixed with the inorganic fine particles are preferably used.

  As the ionomer described in (3), for example, Surlyn A (manufactured by DuPont), Chemipearl S series (manufactured by Mitsui Petrochemical Co., Ltd.), or the like can be used. Further, for example, the above-mentioned inorganic fine particles, a resin binder that can be mixed with the inorganic fine particles, or other resins and fine particles can be further added to the ionomer.

  In order to form a non-transferable release layer, a coating solution containing any one of the above components (1) to (3) in a predetermined blending ratio is prepared, and the coating solution is subjected to gravure coating, gravure reverse coating. The coated layer is dried on a support by a known technique such as a method. The thickness of the non-transferable release layer is usually about 0.1 to 2 μm after drying.

  The heat transferable protective layer (protective transfer layer) laminated on the support with or without a non-transferable release layer may have a multilayer structure or a single layer structure. Good. In the case of a multi-layer structure, in addition to the main protective layer, which is the main component for imparting various durability to the image, thermal transfer protection is provided to enhance the adhesion between the heat transfer protective layer and the image receiving surface of the print. An adhesive layer disposed on the outermost surface of the layer, an auxiliary protective layer, and a layer for adding a function other than the original function of the protective layer (for example, an anti-counterfeit layer, a hologram layer, etc.) may be provided. The order of the main protective layer and the other layers is arbitrary, but usually other layers are arranged between the adhesive layer and the main protective layer so that the main protective layer becomes the outermost surface of the image receiving surface after transfer. .

  The main protective layer that forms one layer of the heat transferable protective layer having a multilayer structure or the heat transferable protective layer having a single layer structure can be formed of various resins conventionally known as protective layer forming resins. Examples of the resin for forming the protective layer include polyester resins, polystyrene resins, acrylic resins, polyurethane resins, acrylic urethane resins, resins obtained by silicone-modifying these resins, mixtures of these resins, ionizing radiation curable resins, An ultraviolet blocking resin can be exemplified.

  The protective layer containing the ionizing radiation curable resin is particularly excellent in plasticizer resistance and scratch resistance. As the ionizing radiation curable resin, known ones can be used. For example, a radical polymerizable polymer or oligomer is crosslinked and cured by ionizing radiation irradiation, and a photopolymerization initiator is added if necessary, and an electron beam Those obtained by polymerization and crosslinking with ultraviolet rays can be used.

  The main purpose of the protective layer containing the ultraviolet blocking resin is to impart light resistance to the printed material. As the ultraviolet blocking resin, for example, a resin obtained by reacting and bonding a reactive ultraviolet absorber with a thermoplastic resin or the above ionizing radiation curable resin can be used. More specifically, a conventionally known non-reactive organic ultraviolet absorber such as salicylate, benzophenone, benzotriazole, substituted acrylonitrile, nickel chelate or hindered amine is added to an addition polymerizable double bond ( Examples thereof include those in which a reactive group such as a vinyl group, an acryloyl group, a methacryloyl group), an alcoholic hydroxyl group, an amino group, a carboxyl group, an epoxy group, or an isocyanate group is introduced.

  The main protective layer provided in the heat transferable protective layer having a single layer structure or the heat transferable protective layer having a multilayer structure as described above is usually about 0.5 to 10 μm, although it depends on the kind of the resin for forming the protective layer. Form to thickness.

  An adhesive layer may be formed on the outermost surface of the heat transferable protective layer. The adhesive layer may be formed of a resin having good adhesiveness when heated, such as an acrylic resin, a vinyl chloride resin, a vinyl acetate resin, a vinyl chloride / vinyl acetate copolymer resin, a polyester resin, and a polyamide resin. it can. In addition to the above resin, the above-mentioned ionizing radiation curable resin, ultraviolet blocking resin and the like may be mixed as necessary. The thickness of the adhesive layer is usually 0.1 to 5 μm.

  In order to form a thermal transferable protective layer on a non-transferable release layer or on a support, for example, a protective layer coating solution containing a protective layer forming resin, or an adhesive layer coating solution containing a thermal adhesive resin In addition, other coating liquids for forming a layer to be added as necessary are prepared in advance, and these are applied in a predetermined order on the non-transferable release layer or the support and dried. Each coating solution may be applied by a conventionally known method. Moreover, you may provide an appropriate primer layer between each layer.

  Further, when a post-chelate dye is used as the dye precursor in the above-described thermal transferable protective layer, a dye fixing body (metal source) described later can be contained for the purpose of increasing the chelate property after dye transfer.

The addition amount of the metal source is preferably 0.01 to 1% by mass, particularly preferably 0.05 to 0.5% by mass, based on the total solid content of the layer to be contained, but the addition amount varies depending on the application. There is no particular limitation.
(Non-transferable resin layer)
In the thermal transfer recording of the present invention, the transferred surface after dye transfer on the recording medium faces the resin layer surface of the non-transferable resin layer, and heat is applied from the side opposite to the non-transferable resin layer. Reheating treatment can be performed.

  The non-transferable resin layer used in the present invention can also be provided on the same surface as the dye layer in a so-called surface sequential manner. When the non-transferable resin layer is used alone as a sheet, the same support and back layer as those described above can be used.

  As the binder resin used for the non-transferable resin layer, the same binder resin as that used for the dye layer can be used.

  When the non-transferable resin layer is provided in the surface order with the dye layer, the resin layer preferably contains fine particles. This means that when stored in a roll state after application, the dye migrates slightly to the back layer, and when the product is in a small volume, the dye migrated to the back layer is retransferred to the non-transferable resin layer. This is performed for the purpose of preventing the phenomenon of so-called kickback. When kickback occurs, the dye retransferred to the resin layer colors the image receiving surface during printing, and the image quality is significantly impaired. As fine particles, in addition to inorganic fine particles such as silica, alumina and calcium carbonate, fine resin particles such as acrylic resin, fluororesin, polyethylene resin and polystyrene resin, or wax particles can be used. The particle diameter of these fine particles is preferably 0.1 to 50 μm. If the thickness is less than 0.1 μm, the resin layer surface has too little unevenness and has no effect on kickback, and if it exceeds 50 μm, the image surface after printing is roughened and the image quality is impaired. A preferable addition amount of the fine particles is 1 to 50% by mass, particularly preferably 5 to 30% by mass with respect to the total solid content of the resin layer. If the amount is less than 1% by mass, the unevenness of the resin layer surface is so small that the effect on kickback is small, and if it exceeds 50% by mass, the image surface after printing is roughened and the image quality is impaired.

  In the heat-sensitive recording material or thermal transfer sheet of the present invention, for the purpose of completing the reaction of the reactive dye during the reheating treatment, the resin layer contains a dye fixing body or a layer containing a dye fixing body. Is provided. In the case of providing a layer containing a dye fixing member, the same binder resin as that used for the dye layer can be used. When a post-chelate dye is used as the dye precursor, it is preferable to contain a metal source as the dye fixing body.

As a metal source used for this invention, the compound represented by general formula (VI) is preferable.
General formula (VI) [M (Q ₁ ) _a (Q ₂ ) _b (Q ₃ ) _c ] ^{p +} (Y ⁻ ) _p

In the formula, M represents a metal ion, preferably Ni ²⁺ , Cu ²⁺ , Cr ²⁺ , Co ²⁺ , Zn ²⁺ .

Q ₁ , Q ₂ , and Q ₃ each represent a coordination compound capable of coordinating with the metal ion represented by M, and may be the same or different from each other. These coordination compounds can be selected from, for example, coordination compounds described in Chelate Science (5) (Nan Edo).

  Y represents an organic anion group, and specific examples thereof include a tetraphenyl boron anion and an alkylbenzene sulfonate anion.

a represents 1, 2 or 3, b represents 1, 2 or 0, and c represents 1 or 0. These are compounds in which the complex represented by the general formula (II) is tetradentate or hexadentate. Or the number of ligands of Q ₁ , Q ₂ , Q ₃ .

  p represents 0, 1 or 2. p = 0 indicates that the coordination compound represented by Q is an anionic compound, and the anionic compound represented by Q and the metal cation represented by M are electrically neutralized. means. As an anionic compound, the compound represented by the following general formula (VII) is preferable.

Formula (VII) OC (R ₅ ) ═CH (R ₇ ) COR ₆

In the formula, R ₅ and R ₆ each represent the same or different alkyl group or aryl group, and R ₇ represents an alkyl group, an alkoxy group, an alkoxycarbonyl group, a halogen atom, or a hydrogen atom.

  The addition amount of the metal source is preferably 0.01 to 1% by mass, particularly preferably 0.05 to 0.5% by mass, based on the total solid content of the resin layer (including when it is provided as a dye fixing body-containing layer). %. When the amount is less than 0.01% by mass, the effect of addition is small, and when the amount is more than 1% by mass, the above-described kickback is more noticeable.

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

  The specific structure of the compound represented by general formula (VII) and the corresponding metal source (VI) is shown.

(Intermediate layer of image receiving sheet)
At least one intermediate layer or more may be provided between the image receiving layer of the image receiving sheet and the support. The intermediate layer means all layers provided between the image receiving layer and the support, such as an adhesive layer (primer layer), a barrier layer, an ultraviolet absorbing layer, a foamed layer, an antistatic layer, etc. Either can be used. Furthermore, it is preferable to add a white pigment such as titanium oxide to the intermediate layer in order to conceal the glare and unevenness of the support because the degree of freedom in selecting the support is widened. The content of the intermediate layer resin and the white pigment is preferably 30 to 300 parts by mass of the white pigment solid content with respect to 100 parts by mass of the resin solid content. Is more preferable.

  As the intermediate layer, a layer obtained by curing a thermoplastic resin, a thermosetting resin, or a thermoplastic resin having a functional group by using various additives or other methods can be used. Specifically, polyvinyl alcohol, polyvinyl pyrrolidone, polyester, chlorinated polypropylene, modified polyolefin, urethane resin, acrylic resin, polycarbonate, ionomer, resin having a monofunctional and / or polyfunctional hydroxyl group-containing prepolymer cured with isocyanate or the like Etc. can be used.

(Image receiving layer)
The image receiving layer is composed of a dye fixing member, a binder resin, and, if necessary, various additives such as a release agent on one surface of the support. When a post-chelate dye is used as the dye precursor, a metal source is contained as a dye fixing body. As described above, when a chelate pigment is used as a dye, the metal source may not be added or may be added as appropriate. As the metal source, those used in the above-described non-transferable resin layer can be similarly used. The addition amount of the metal source is usually preferably 10 to 60% by mass and more preferably 20 to 50% by mass with respect to the solid content of the image receiving layer.

  A well-known thing can be used for binder resin, It is preferable to use what a dye is easy to dye. Specifically, polyolefin resins such as polypropylene, halogenated resins such as polyvinyl chloride and polyvinylidene chloride, vinyl resins such as polyvinyl acetate and polyacrylate, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polystyrene Resins, polyamide resins, phenoxy resins, copolymers of olefins such as ethylene and propylene and other vinyl monomers, polyurethane, polycarbonate, acrylic resins, ionomers, cellulose derivatives, etc. can be used alone or as a mixture, Among these, polyester resins and vinyl resins are preferable.

  The image-receiving layer is preferably added with a release agent in order to prevent thermal fusion with the dye layer. As the mold release agent, a phosphoric ester plasticizer, a fluorine compound, silicone oil (including reaction curable silicone) and the like can be used, and among these, silicone oil is preferable. As the silicone oil, various modified silicones such as dimethyl silicone can be used. Specifically, amino-modified silicones, epoxy-modified silicones, alcohol-modified silicones, vinyl-modified silicones, urethane-modified silicones, and the like can be blended or polymerized using various reactions. One or more release agents are used. Further, the addition amount of the release agent is preferably 0.5 to 30 parts by mass with respect to 100 parts by mass of the image receiving layer forming resin. When the range of the addition amount is not satisfied, problems such as fusion between the thermal transfer sheet and the image receiving layer of the image receiving sheet or a decrease in printing sensitivity may occur. These releasing agents may not be added to the image receiving layer, but may be provided separately as a releasing layer on the image receiving layer.

(Back side resin layer or back side layer of image receiving sheet)
The back surface resin layer or back surface layer of the image receiving sheet may contain a compound for the purpose of improving the machine transportability of the image receiving sheet, preventing charging, imparting writing properties, sticking to stamps, and the like. In order to obtain an antistatic function, a layer made of a conductive resin such as an acrylic resin or a conductive filler, and further a fatty acid ester, a sulfate ester, a phosphate ester, an amide, a quaternary ammonium salt, a betaine, an amino acid A layer to which an antistatic agent such as ethylene oxide additions is added may be formed.

The amount of the antistatic agent used varies depending on the layer to which the antistatic agent is added and the type of the antistatic agent, but in any case, the surface electrical resistance value of the image receiving sheet is preferably 1013 ohm / cm ² or less. If it is larger than 1013 ohm / cm ² , the image receiving sheets stick to each other due to electrostatic contact, causing a paper feeding trouble. The amount used is preferably 0.01 to 3.0 g / m ² . When the amount of the antistatic agent used is less than 0.01 g / m ² , the antistatic effect is insufficient. On the other hand, when it exceeds 3.0 g / m ² , the effect is not improved and it is uneconomical and sticky. Such problems may occur.

  The writing layer may be provided on the entire surface of the image receiving sheet or may be partially formed.

  In addition, for the purpose of improving transportability, addition of nylon resin particles and higher fatty acid salts is also effective. Examples of nylon resin particles include nylon 12 and nylon 6 particles. These nylon resin particles may be used alone or in combination of two or more.

  As the higher fatty acid salt, for example, calcium stearate, magnesium stearate, barium stearate, zinc stearate and the like can be used.

The writing layer forming means may be a conventionally known printing coating means. The thickness of the writing layer is about 0.5 to 20 g / m ² when dried.
(Image receiving sheet support)
The support of the image receiving sheet has a role of holding the image receiving layer and heat is applied at the time of thermal transfer. Therefore, it is preferable that the support has a mechanical strength that does not hinder handling even in an overheated state.

  The material of such a support is not particularly limited. For example, condenser paper, glassine paper, sulfuric acid paper, high-size paper, synthetic paper (polyolefin-based, polystyrene-based), high-quality paper, art paper, coated paper, Cast coated paper, wallpaper, backing paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internal paper, paperboard, cellulose fiber paper, or polyester, polyacrylate, polycarbonate, polyurethane, polyimide, polyetherimide , Cellulose derivatives, polyethylene, ethylene-vinyl acetate copolymer, polypropylene, polystyrene, acrylic, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyether ether ketone, polysulfone, polyethylene Examples include films of tersulfone, tetrafluoroethylene, perfluoroalkyl vinyl ether, polyvinyl fluoride, tetrafluoroethylene / ethylene, tetrafluoroethylene / hexafluoropropylene, polychlorotrifluoroethylene, polyvinylidene fluoride, etc. A white opaque film formed by adding a white pigment or a filler to the above synthetic resin or a foamed foam sheet can be used, and is not particularly limited.

  Moreover, the laminated body by the arbitrary combinations of the said support body can also be used. Examples of typical laminates include cellulose fiber paper and synthetic paper, or synthetic paper of cellulose synthetic paper and a plastic film. The thickness of these supports may be arbitrary and is usually about 10 to 300 μm.

  In order to obtain higher printing sensitivity and high image quality without density unevenness or white spots, it is preferable to have a layer having fine voids (hereinafter sometimes referred to as a fine void resin layer). As the fine void resin layer, a plastic film or synthetic paper having fine voids inside can be used. Moreover, a fine void resin layer can be formed on various supports by various coating methods. As a plastic film or synthetic paper having fine voids, polyolefin, especially polypropylene, is mainly blended with an inorganic pigment and / or a polymer incompatible with polypropylene, and these are used as void (void) formation initiators. A plastic film or synthetic paper obtained by stretching and forming a mixture of the above is preferable. In the case where these are mainly polyester, the cushioning properties and heat insulation properties are inferior to those mainly consisting of polypropylene due to their viscoelastic or thermal properties, so the printing sensitivity is inferior. Concentration unevenness is also likely to occur.

Considering these points, the elastic modulus at 20 ° C. of the plastic film and the synthetic paper is preferably 5 × 10 ⁸ Pa to 1 × 10 ¹⁰ Pa. In addition, since these plastic films and synthetic paper are usually formed by biaxial stretching, they shrink by heating. When these are left at 110 ° C. for 60 seconds, the shrinkage is 0.5 to 2.5%. The plastic film and the synthetic paper described above may be combined with each other as a single layer including fine voids, or may have a plurality of layers. In the case of a plurality of layer structures, all the layers constituting the structure may contain fine voids, or a layer containing no fine voids may be contained. A white pigment may be mixed in the plastic film or synthetic paper as a concealing agent as necessary. In order to increase whiteness, an additive such as a fluorescent brightener may be included. The fine void resin layer preferably has a thickness of 30 to 80 μm.

  As the fine void resin layer, the fine void resin layer can be formed on the support by a coating method. As the plastic resin to be used, known resins such as polyester, urethane resin, polycarbonate, acrylic resin, polyvinyl chloride, and polyvinyl acetate can be used singly or in combination. As the support, the above-described various papers, synthetic papers, non-woven fabrics, plastic films and the like can be used.

If necessary, on the surface of the support opposite to the side on which the image receiving layer is provided, for the purpose of preventing curling, polyvinyl alcohol, polyvinylidene chloride, polyethylene, polypropylene, modified polyolefin, polyethylene terephthalate, polycarbonate, etc. A layer of resin or synthetic paper can be provided. As a bonding method, for example, known lamination methods such as dry lamination, non-solvent (hot melt) lamination, EC lamination method and the like can be used, but preferred methods are dry lamination and non-solvent lamination. An example of an adhesive suitable for the non-solvent lamination method is Takenate 720L manufactured by Takeda Pharmaceutical Co., Ltd., and an example of an adhesive suitable for dry lamination is Takelac A969 / Takenate A manufactured by Takeda Pharmaceutical Co., Ltd. -5 (3/1), manufactured by Showa Polymer Co., Ltd., Polysol PSA SE-1400, Vinylol PSA AV-6200 series and the like. The amount of these adhesives, from about 1-8 g / ^{m 2} on a solids, and preferably from 2 to 6 g / ^{m 2.}

  When the plastic film and the synthetic paper as described above, or between them, or various papers and the plastic film or the synthetic paper are laminated, they can be bonded together by an adhesive layer.

  For the purpose of increasing the adhesive strength between the support and the thermal transfer image-receiving layer, various primer treatments and corona discharge treatments are preferably performed on the surface of the support.

(Layer structure, coating method, etc.)
The above thermal transfer image-receiving layer is a reverse coating using a bar coater, gravure printing method, screen printing method, roll coating method, gravure plate, coating solution dissolved or dispersed in a solvent such as water or an organic solvent on a support. It can be formed by applying by ordinary methods such as a roll coating method, an air knife coating method, a spray coating method, a curtain coating method, and an extrusion coating method, and then drying. The barrier layer, the intermediate layer, and the back layer are formed by the same method as that for the image receiving layer. In addition, the image receiving layer is not only formed by directly applying the coating liquid on the support and drying as described above, but also having an image receiving layer previously formed on another support. The image receiving layer may be transferred and formed. Further, two or more layers can be coated by the simultaneous coating method, and in particular, all the layers can be coated by one coating.

The thickness of the image receiving layer is the thickness after coating and drying, and is preferably about 0.1 to 10 μm.
(Image receiving sheet shape)
The image receiving sheet used in the present invention may be supplied to the printer as a single sheet or as a roll. The sheet supply refers to, for example, a form in which an image receiving sheet is cut into a certain size, about 50 sheets are put in a cassette and mounted on a printer. The roll form is a form in which the image-receiving sheet is supplied to the printer in that form and cut into a desired size after printing. In particular, the latter is preferable because troubles in the conveyance system such as feeding failure and ejection failure such as inserting two sheets can be solved and the capacity of the printable sheet can be increased.

  When supplying the image receiving sheet in a roll form, particularly when the postcard specification is as described above, or when using a label or a seal type image receiving sheet, a design mark such as a postal code frame formed on the back side, In order to align the cutting position with the half-cut position of the seal, a detection mark can be provided on the back side.

(Chelate recording method)
Next, an example of the thermal transfer recording method of the present invention will be shown.
An embodiment in the case where the transparent protective layer or the non-transferable resin layer is supplied in the surface order with the dye layer of the thermal transfer sheet will be described with reference to the drawings. FIG. 1 is a view showing a thermal transfer sheet according to one embodiment of the present invention. In FIG. 1 a, the yellow (Y), magenta (M), and cyan (C) dye layer 2 is provided on the same plane of the support 3, and in some cases, a transparent protective layer or a non-transferable resin layer is provided on the surface. It is provided sequentially.

  In FIG. 1, no gap is formed between the layers, but a suitable gap may be provided in accordance with the control method of the thermal transfer recording apparatus. Moreover, in order to perform the cueing of each layer with good system, it is preferable to provide the detection mark on the thermal transfer sheet, and the way of providing is not particularly limited. In a, a dye layer and a transparent protective layer or a non-transferable resin layer are provided on the same plane of the support, but it goes without saying that each may be provided on a separate support. In addition, although it is a definition of a dye layer, when a reactive dye is used, the dye itself contained in the dye layer is a compound before the reaction, and strictly speaking, it cannot be said to be a Y, M, or C dye. , Y, M, and C are similarly expressed for convenience in the meaning of a layer for finally forming an image.

(Chelate recording device)
As the thermal transfer recording apparatus used in the present invention, for example, an apparatus as shown in FIG. 2 can be used. In FIG. 2, 10 is a thermal transfer sheet supply roll, 15 is a thermal transfer sheet, 11 is a take-up roll for winding the used thermal transfer sheet 15, 12 is a thermal head, 13 is a platen roller, 14 is a thermal head 12 and a platen roller 13. Is an image receiving sheet inserted between the two.

  In the thermal transfer printer used in the present invention, it is preferable that glossy tone and matte tone control can be selected in the same printer, since a printed matter having a desired surface property can be obtained with one model. The selection method is not particularly limited. For example, if control data corresponding to a certain glossy tone and matte tone is held in the thermal transfer recording apparatus, the control data selected by a simple operation of the operator is read, and the control unit is controlled according to the data. Alternatively, when a personal computer is connected to the printer, the control data may be held on the personal computer side and the selected control data may be sent to the printer by a simple operation by the operator. In addition, when heating with a heat roller, a material that alters the surface, for example, a release sheet that gives gloss, a sheet with unevenness for matting is applied to the surface of the image receiving layer after image recording. By heating with a heat roller from the back side of the sheet, recording bodies having different surfaces can be obtained.

(Post-heating method)
In the thermal transfer method of the present invention, the recording material obtained by thermal transfer recording may be subjected to a heating step after image formation.

  Heating after image formation is performed for the purpose of fixing the transferred dye in the image receiving layer for thermal transfer recording.

  Examples of the heating method include a method using a thermal head used for thermal transfer recording, a method using a heat roller, a method using a heater or a hot air heater, and a method using electron beam radiation or infrared radiation.

  Heating of the recording medium can be performed from both the front and back surfaces of the recording medium or from one surface, and one surface or both surfaces are simultaneously performed, and one of the surfaces is displaced or simultaneously performed.

  In the present invention, a preferable heating method is a method using a thermal head or a method using a heat roller.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples.

  Hereinafter, a specific example will be described. In the text, “part” or “%” is based on mass unless otherwise specified.

[Preparation of thermal transfer sheet (hereinafter also referred to as ink sheet) 1]
(Preparation of support A with back coat layer)
A back coat layer coating solution 1 having the following composition is applied to one side of a 4.5 μm thick polyethylene terephthalate film with an easy-contact layer (Lumirror manufactured by Toray Industries, Inc.) by a gravure coating method, dried, and then heated. Curing treatment was performed to prepare a support A having a back coat layer having a dry film thickness of 1.0 μm.

<Preparation of backcoat layer coating solution 1>
Polyvinyl butyral resin (Sekisui Chemical Co., Ltd. ESREC BX1) 3.5 parts by mass Phosphate-based surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Prisurf A208S)
3.0 parts by mass phosphate ester surfactant (Phosphanol RD720 manufactured by Toho Chemical Co., Ltd.)
0.3 part by mass polyisocyanate (Dainippon Ink & Chemicals, Barnock D75045)
19.0 parts by mass Talc (manufactured by Nippon Talc Co., Ltd. Y / X = 0.03) 0.2 parts by mass Methyl ethyl ketone 35.0 parts by mass Toluene 35.0 parts by mass

[Formation of dye layer and protective transfer layer]
Each dye layer formed using a yellow dye coating liquid 1, a magenta dye coating liquid 1, and a cyan dye coating liquid 1 having the following composition on the surface opposite to the back coat surface of the support A with the back coat layer ( A dry film thickness of 1 μm) and a multi-layer protective transfer layer (a three-layer structure of a non-transferable release layer / protective transfer layer / adhesive layer) are provided in the surface order as shown in FIG. 3 by the gravure method. A thermal transfer sheet 1 was prepared.

[Each dye layer]
<Yellow dye coating solution 1>
Post-chelate dye (JP 2004-74617 Exemplified Compound (1) -32)
4.5 parts by mass of polyvinyl acetoacetal resin (manufactured by Sekisui Chemical Co., Ltd., ESREC KS5) 5.0 parts by mass of urethane-modified silicone resin (Dairoma Seika Co., Ltd., Dialomer SP2105)
0.5 parts by mass Methyl ethyl ketone 45.0 parts by mass Toluene 45.0 parts by mass

<Magenta dye coating solution 1>
Post-chelate dye (JP 2004-74617 Exemplified Compound (2) -38)
4.0 parts by mass of polyvinyl acetoacetal resin (manufactured by Sekisui Chemical Co., Ltd., ESREC KS5) 5.5 parts by mass of urethane-modified silicone resin (manufactured by Dainichi Seika Co., Ltd., Dialomer SP2105)
0.5 parts by mass Methyl ethyl ketone 45.0 parts by mass Toluene 45.0 parts by mass

<Cyan dye coating solution>
Post-chelate dye Exemplified compound 47 4.0 parts by mass polyvinyl acetoacetal resin (manufactured by Sekisui Chemical Co., Ltd., ESREC KS5) 5.5 parts by mass urethane-modified silicone resin (manufactured by Dainichi Seika Co., Ltd., Dialomer SP2105)
0.5 parts by mass Methyl ethyl ketone 45.0 parts by mass Toluene 45.0 parts by mass

[Multi-layer protective transfer layer]
(Non-transferable release layer)
A non-transferable release layer coating liquid 1 having the following composition was applied by a gravure coating method so that the solid content after drying was 0.5 g / m ² and dried to form a non-transferable release layer. .

<Non-transferable release layer coating solution 1>
Colloidal silica (Snowtex 50, manufactured by Nissan Chemical Co., Ltd.) 1.5 parts by mass polyvinyl alcohol 4.0 parts by mass ion-exchanged water 3.0 parts by mass denatured ethanol 10 parts by mass

(Protective transfer layer)
On the formed non-transferable release layer, a protective transfer layer coating solution 1 having the following composition was applied and dried by a gravure coating method so that the solid content after drying was 2.0 g / m ² . A protective transfer layer was formed.

<Protective transfer layer coating solution 1>
Acrylic resin 15 parts by mass Vinyl chloride-vinyl acetate copolymer 5 parts by mass Copolymerized resin reactive UV absorber (UVA-635L manufactured by BASF Japan)
40 parts by mass polyethylene wax 0.3 parts by mass polyester resin 0.1 parts by mass methyl ethyl ketone 40 parts by mass Toluene 40 parts by mass Zinc antimonate (Sellnax manufactured by Nissan Chemical Co., Ltd.) 20 parts by mass

(Adhesive layer)
On the protective transfer layer thus formed, the adhesive layer coating solution 1 having the following composition was applied and dried by a gravure coating method so that the solid content after drying was 2.0 g / m ^2, and the adhesive layer layer Formed.

<Adhesive layer coating solution 1>
Vinyl chloride-vinyl acetate copolymer 20 parts by mass Methyl ethyl ketone 100 parts by mass Toluene 100 parts by mass By the above, the protective transfer layer, which is a laminate of the protective transfer layer and the adhesive layer, can be peeled off on the non-transferable release layer A provided multi-layer protective transfer layer was prepared.

<Creation of thermal transfer sheet 2-6>
Thermal transfer sheets 2-6 were prepared in which the cyan dye of the thermal transfer sheet 1 was changed from the exemplified compounds 47 to 26, 46, 49, 63, and the dye of the structural formula 1.

<Creation of thermal transfer sheet comparisons 1, 2, and 3 (comparison)>
Thermal transfer sheet comparison 1, comparison 2 and comparison 3 were prepared by changing the cyan dye of the thermal transfer sheet 1 from the exemplified compound 47 to the comparative dyes 1, 2 and 3.
Table 6 shows the prepared thermal transfer sheet.

[Preparation of thermal transfer image-receiving sheet 1]
A thermal transfer image receiving sheet 1 was produced according to the following contents.
(Production of support)
As a support for the image-receiving sheet, coated paper (US basis weight 157 g / m ² OK Top Coat S, manufactured by Oji Paper Co., Ltd.) was used, and after one side was subjected to corona discharge treatment, High density polyethylene (J-Rex LZ01392, density 0.952, manufactured by Nippon Polyolefin Co., Ltd., hereinafter abbreviated as HDPE) blended with 15% by mass of an ethylene α-olefin copolymer (Tuffmer A4085, Mitsui Petrochemical Co., Ltd.), Two layers of polypropylene (J-Alomer LR7115, density 0.905, manufactured by Nippon Polyolefin Co., Ltd., hereinafter abbreviated as PP) are coextruded so that the HDPE side is in contact with the coated paper by a coextrusion coating method using a known multilayer T die. And laminated. Further, after the corona discharge treatment is performed on the PP surface which is on the outside, the back layer coating solution 1 having the following composition is applied and dried so that the dry solid content is 1.5 g / m ² . Support B was prepared. The thickness of the back surface resin layer was processed so that the HDPE layer of the ethylene α-olefin copolymer blend was 14 μm and the PP layer was 19 μm, for a total of 33 μm.

<Preparation of backside layer coating solution 1>
Acrylic resin (BR85 manufactured by Mitsubishi Rayon Co., Ltd.) 19.8 parts by mass Nylon filler (MW330, manufactured by Shinto Paint Co., Ltd.) 0.6 parts by mass Methyl ethyl ketone 39.8 parts by mass Toluene 39.8 parts by mass

(Preparation of thermal transfer image receiving sheet)
On the other hand, a foamed polypropylene sheet (35 MW846 Mobile Plastics Europe) having a thickness of 35 μm was used as the resin layer having fine voids, and an intermediate layer coating solution having the following composition and a dye image-receiving layer coating were formed on one surface thereof. The foam is coated with the liquid by the gravure reverse coating method so that the coating thickness when dried is 1 μm and 3 μm, respectively, and dried to produce a foamed polypropylene sheet in which the intermediate layer and the dye image-receiving layer are laminated. did.

  Next, the surface of the foamed polypropylene sheet on which the intermediate layer and the dye image-receiving layer are not provided (foamed polypropylene sheet surface) and the surface of the support B on which the back resin layer is not provided (coated paper surface) A thermal transfer image-receiving sheet 1 was prepared by laminating with an adhesive having the following composition by a dry laminating method.

<Preparation of intermediate layer coating solution>
Urethane resin (Nipporan 5199, manufactured by Nippon Polyurethane Co., Ltd.) 5.7 parts by mass Titanium oxide (TCA888, manufactured by Tochem Products) 11.4 parts by mass Optical brightener (Ubitex OB, manufactured by Ciba Geigy Japan) 0.2 Isocyanate (Takenate A14, Takeda Pharmaceutical Company Limited) 2.0 parts by mass Methyl ethyl ketone 15.5 parts by mass Toluene 15.5 parts by mass Isopropyl alcohol 7.7 parts by mass

<Preparation of dye image-receiving layer coating solution>
Vinyl chloride vinyl acetate copolymer (Denka vinyl # 1000A, manufactured by Denki Kagaku Kogyo Co., Ltd.)
7.2 parts by mass of vinyl chloride styrene acrylic copolymer (Denkarak # 400, manufactured by Denki Kagaku Kogyo Co., Ltd.)
1.6 parts by mass polyester (byron 600 manufactured by Toyobo Co., Ltd.) 11.2 parts by mass metal source (general compound VI exemplified compound (VI) -1) 8.0 parts by mass vinyl-modified silicone (X621212 manufactured by Shin-Etsu Chemical Co., Ltd.) 2 1.0 part by mass catalyst: CAT PLR5 (manufactured by Shin-Etsu Chemical Co., Ltd.) 1.0 part by mass catalyst: CAT PL50T (manufactured by Shin-Etsu Chemical Co., Ltd.) 1.2 parts by mass Solvent: methyl ethyl ketone 39.0 parts by mass Solvent: toluene 39.0 Parts by mass

<Creation of image receiving sheet 2-4>
In the image receiving sheet 1, an image receiving sheet 2-4 in which the metal source in the image receiving layer coating solution was changed from VI-1 to VI-2, VI-5, VI-7 was prepared. The addition amount of the metal source was added so that the metal ion content was equal according to the molecular weight of each.
The created image receiving sheet is shown in Table 7.

Example 1
A thermal transfer image receiving device is mounted on a thermal transfer recording apparatus equipped with a thermal head having a square shape (main scanning direction length 80 μm × sub scanning direction length 120 μm), 300 dpi (dpi represents the number of dots per 2.54 cm) line head. Yellow, which is set by superimposing the image receiving layer of sheet 1 and the thermal transfer sheet 1-6, and the ink layers of comparisons 1 and 2, and sequentially increasing in an applied energy range of 580 mJ / mm ² while being pressed by a thermal head and a platen roll. , Magenta, cyan, and neutral (yellow, magenta, and cyan three-color overlapping) step patterns are heated from the back side of the ink layer at a feed rate of 10 msec / line and a feed length per line of 85 μm, Each dye was transferred onto the image receiving layer of the thermal transfer image receiving sheet to form an image.

Next, using the same thermal transfer recording apparatus as that used for image formation, the image-receiving sheet on which the image was formed and the produced multi-layered protective transfer layer were superposed and pressed with a thermal head and a platen roll, 80 mJ / Heating from the back side of the protective layer transfer sheet at an applied energy of mm ² and a feed rate of 10 msec / line, the protective layer is transferred to the entire surface of the image of the image receiving sheet, and print samples 1-1-1 to 1-1-6 , And 1-1-Comparison 1 and 2 were prepared.

Similarly, samples 1-2-1 to 1-4-6 and 1-2 comparison 1 to 1-4 comparison 2 on which an image was formed on the image receiving sheet 2-4 were prepared.
(Sensitivity, light resistance, moisture resistance, heat resistance, yellowing, image bleeding)
For the prepared sample, the density Ci after the transfer was measured with X-rite 310, and then irradiated with 85000 lux xenon light for 14 days using an Atlas weather meter, the density Cf was measured again, and the dye residual ratio ( Cf / Ci) × 100 was determined.

The maximum density (Dmax) values of cyan and neutral were shown.
Further, the energy giving a cyan density and a neutral density of 1.0 is shown as a relative value. In this case, 1-1-Comparison 1 was used as a reference. A lower value indicates higher sensitivity.

Further, when the dye residual ratio is 90% or more for all the cyan and neutral densities, the light resistance A,
Light resistance B for 80% or more
The case of 70% or more was defined as light resistance C.

  In addition, when the prepared sample was left to stand for 14 days under a high-temperature and high-humidity condition of 60 ° C. and 90% RH, and when the sample was left to stand for 14 days under a high-temperature condition of 77 ° C. and 10% RH, The bleeding was evaluated visually.

White background change: ○ No yellowing
× Yellowing color bleeding: ○ None
× Yes

(Raw preservation)
Thermal transfer ink sheet 1-6, and comparisons 1 and 2 A) 40 ° C. 80% RH 100h
B) 55 ° C 10% 48h
The ink sheet after storage was visually observed and evaluated for changes such as pigment deposition.

○: There is no change with both A) and B) conditions. Δ: A slight amount of dust is observed under either of the conditions. A: Precipitation is clearly observed with both A) and B).
Table 8 shows the above results.

Example 2
<Creation of thermal transfer sheet 7-12>
A thermal transfer sheet 7-12 in which the binder amount was changed so that the cyan dye density of the thermal transfer sheet 1-6 of Example 1 was 1.4 times was prepared.

<Creation of thermal transfer sheet comparisons 4, 5 and 6 (comparison)>
Thermal transfer sheet comparisons 4, 5 and 6 were prepared in which the binder amount was changed so that the density of the cyan dyes in the thermal transfer sheet comparison 1, comparison 2 and comparison 3 of Example 1 was 1.4 times.
Table 9 shows the prepared thermal transfer sheet.

  Comparisons 1, 2 and 3 of the cyan dyes used in the samples for comparison are as follows.

  The thermal transfer sheet 7-12 and the comparisons 4, 5 and 6 were prepared by transferring the dye (dye) to the image receiving sheet 1-4 using the thermal head in the same manner as in Example 1.

  These samples were evaluated for maximum transfer density, sensitivity, light resistance, white background change, and color bleeding as in Example 1.

In addition, as in Example 1, thermal transfer ink sheet 7-12, comparisons 4, 5 and 6 were: A) 40 ° C. 80% RH 100h
B) 55 ° C 10% RH 48h
The ink sheet after storage was visually observed and evaluated for changes such as pigment deposition.
The results are shown in Table 10.

  From the above results, the thermal transfer recording material of the present invention has good storage stability of the ink sheet, high sensitivity of the obtained image, good storage stability, high temperature and high humidity, or yellowing of the white background under high temperature conditions. It can be seen that a stable image without any is obtained.

Example 3 (chelating dye)
A thermal transfer sheet was prepared using a chelate dye instead of the post-chelate dye of the thermal transfer sheet prepared in Example 1. The types of chelate dyes are as shown in Table 11 below.

  The image receiving sheet was prepared in the same manner as in Example 1 except that the metal source was removed from the composition of the image receiving sheet in Example 1.

  Using these prepared thermal transfer sheets and image receiving sheets, Samples 3-1 to 3-10 on which a cyan image and a neutral image were formed using a thermal head in the same manner as in Example 1 were prepared.

  As yellow and magenta dyes, (5) -13 and (6) -13 described in JP-A-2004-74618 were used.

  The sample according to the present invention and the comparative sample were measured by the following methods, and the sensitivity at the time of chelate dye image formation and the fastness of the image (light resistance, heat resistance, moisture resistance) were evaluated. The sensitivity was expressed as a relative value with respect to the energy that gives cyan and neutral density 1.0 of Comparative Example 1 as a reference value. The results are shown in Table 12.

-Evaluation and method-
(Light resistance)
The obtained chelate dye transfer image is irradiated with 85000 lux of xenon light for 14 days, the density before light irradiation is represented by D ₀ , and the density after light irradiation is represented by D ₁ (D ₁ / D ₀ ) × 100. Light resistance was evaluated by the residual ratio (%) of the cyan dye.

(Heat-resistant)
The obtained chelate dye transfer image was stored for 14 days under conditions of 77 ° C. and 10% RH or less, and the concentration before storage start was D ₀ and the concentration after storage was D ₂ (D ₂ / D ₀ ) × 100 The heat resistance was evaluated by the cyan dye residual ratio (%) represented by

(Moisture resistance)
The obtained chelate dye transfer image was stored for 14 days under conditions of 60 ° C. and 90% RH, and the concentration before storage was D ₀ and the concentration after storage was D ₃ (D ₃ / D ₀ ) × 100 The moisture resistance was evaluated by the cyan dye residual ratio (%).

  As is apparent from Table 12, the chelate dye of the present invention has a higher sensitivity than conventional metal complex dyes, and is a dye excellent in light fastness, heat resistance, and moisture fastness of image fastness. Recognize.

It is a top view which shows the example of the aspect of the ink layer provided in the ink sheet used for the method of this invention, and a reheating process layer. It is a conceptual diagram of an example of the thermal transfer recording apparatus used for the method of this invention. It is the schematic which shows the structure of the thermal transfer sheet in an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Protective layer area | region 2Y Area | region 2M containing yellow dye Area | region 2C area | region 2C containing magenta dye Area | region 3 and 3 'containing cyan dye Ink sheet support 10 Ink sheet supply roll 11 Winding roll 12 Thermal head 13 Platen roller 14 Image receiving Sheet 15 Ink sheet

Claims (8)

A thermal transfer recording material comprising at least one dye represented by the following general formula (II).

[Wherein, R ₂₁ and R ₂₂ each represent a substituted or unsubstituted aliphatic group, and R ₂₃ represents a substituent. n represents an integer of 0 to 4, and when n is 2 or more, the plurality of R ₂₃ may be the same or different. R ₂₅ and R ₂₆ represent an alkyl group. However, at least one of R ₂₅ and R ₂₆ represents a secondary alkyl group. ] 2. The thermal transfer recording material according to claim 1, wherein the dye of the general formula (II) is represented by the following general formula (III), (IV) or (V).

[In Formula (III), R ₃₁ and R ₃₂ each represent a substituted or unsubstituted aliphatic group, and R ₃₃ represents a substituent. n represents an integer of 0 to 4, and when n is 2 or more, the plurality of R ₃₃ may be the same or different. ]

[In Formula (IV), R ₄₁ and R ₄₂ each represent a substituted or unsubstituted aliphatic group, and R ₄₃ represents a substituent. n represents an integer of 0 to 4, and when n is 2 or more, the plurality of R ₄₃ may be the same or different. ]

[In Formula (V), R ₅₁ and R ₅₂ each represent a substituted or unsubstituted aliphatic group, and R ₅₃ represents a substituent. n represents an integer of 0 to 4, and when n is 2 or more, the plurality of R ₅₃ may be the same or different. ] The thermal transfer recording material according to claim 1 or 2, wherein the dye represented by at least one of the general formulas (II) to (V) has a molecular weight of 300 to 410. The thermal transfer recording material according to claim 2 or 3, wherein the dye represented by the general formula (IV) is the following structural formula (1).

An image receiving material is superimposed on a thermal transfer recording material having a dye-donating layer containing at least one of the dyes represented by the general formulas (II) to (V) or the structural formula (1) on a support. A thermal transfer recording method, wherein the thermal transfer recording material is heated in accordance with image information to form an image. On a support, a thermal transfer recording material having a dye-donating layer containing at least one of the dyes represented by the general formulas (II) to (V) or the structural formula (1) on the support. An image receiving material having a dye image-receiving layer containing a metal ion-containing compound is superimposed on the heat-sensitive transfer recording material according to image information, and a metal chelate dye image is formed by the reaction between the dye and the metal ion-containing compound. And a thermal transfer recording method. It contains at least one metal chelate dye produced by the reaction of at least one of the general formulas (II) to (V) or the dye represented by the structural formula (1) with a metal ion-containing compound. Thermal transfer recording material. At least one metal chelate dye produced by reaction of at least one of the general formulas (II) to (V) or the dye represented by the structural formula (1) with a metal ion-containing compound is used. Thermal transfer recording method.

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