JP2008087239A - Dye layer forming coating composition of thermosensitive transfer ink sheet, thermosensitive transfer ink sheet, ink cartridge and thermosensitive transfer recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sensitive and image defect-free thermosensitive transfer ink sheet. <P>SOLUTION: In the thermosensitive transfer ink sheet, which keeps a dye layer with a resin binder having a heat-migratory dye therein overlying a support, the resin binder of the dye layer includes a polymer including a repeating unit derived from a monomer expressed with formula [1], R<SP>1</SP>represents a hydrogen atom, a halogen atom or a methyl group, L<SP>1</SP>represents a single bond or a bivalent connecting group under conditions that the atom joining to Y is a heteroatom and Y represents a cyclic atom. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a coating composition for forming a dye layer of a thermal transfer ink sheet, a thermal transfer ink sheet, an ink cartridge, and a thermal transfer recording method, characterized by containing a polymer having a specific structure.

Technical background

  In recent years, a material for forming a color image has been mainly used as an image recording material. Specifically, an inkjet recording material, a thermal transfer type image recording material, a recording material using an electrophotographic system, a transfer type halogen, and the like. Silver halide photosensitive materials, printing inks, recording pens and the like are actively used.

  Among them, for thermal transfer recording, a thermal transfer ink sheet in which a heat-meltable dye layer is formed on a base film as a support is heated by a thermal head to melt the dye and record it on an image receiving sheet, and a base There is a system in which a thermal transfer ink sheet in which a dye layer containing a heat transferable dye is formed on a film is heated by a thermal head to thermally transfer the dye onto the image receiving sheet.

  In the latter thermal diffusion transfer recording method, the thermal transfer ink sheet and the image receiving sheet are overlapped, and then the ink sheet is heated by a thermal head whose heat generation is controlled by an electric signal, whereby the dye in the ink sheet is applied to the image receiving sheet. The image information is recorded by transfer, and a color image having a continuous change in color shading can be transferred and recorded by overlappingly recording three colors of cyan, magenta, and yellow. At this time, since the amount of dye transfer can be changed by changing the amount of heat generated by the thermal head, the thermal diffusion transfer recording method is easy for gradation recording and is particularly advantageous for high-quality full-color recording. .

Conventionally, a polyester resin has been used as a resin binder (ink sheet polymer) that plays a role of retaining a dye in an ink sheet. On the other hand, Patent Document 1 describes that a specific resin binder such as ethyl cellulose or ethyl hydroxyethyl cellulose is used in combination with a specific compatibilizing agent in order to form a high-density color image. . Patent Document 2 describes that a vinyl chloride resin or a polycarbonate resin is used in combination with a (meth) acrylic acid alkyl ester polymer in order to form a high-density color image.
Japanese Patent No. 3207518 Japanese Patent Laid-Open No. 7-25158

  However, in recent years, the printing speed has been remarkably increased, and with the resins described in these patent documents, it has been difficult to achieve both high transfer sensitivity and photographic performance while supporting high transfer speed. ing.

  The present invention relates to a thermal transfer ink sheet, an ink cartridge, a thermal transfer recording method, and a thermal transfer ink sheet for producing the thermal transfer ink sheet capable of forming a high-sensitivity and defect-free image even when high-speed transfer is performed. An object is to provide a coating composition.

  As a result of intensive studies, the present inventors have found that the above problem can be solved by the following configuration.

(1) A coating composition for forming a dye layer of a thermal transfer ink sheet, comprising a heat transferable dye and a polymer containing a repeating unit derived from a monomer represented by the following general formula [1] object.
General formula [1]

（一般式［１］において、Ｒ¹は水素原子、ハロゲン原子またはメチル基を表し、Ｌ¹は単結合、またはＹに結合する原子がヘテロ原子である２価の連結基を表し、Ｙは環状基を表す。）

(In the general formula [1], R ¹ represents a hydrogen atom, a halogen atom or a methyl group, L ¹ represents a single bond or a divalent linking group in which the atom bonded to Y is a hetero atom, and Y represents a cyclic group. Represents a group.)

(2) The coating composition according to (1), wherein the monomer represented by the general formula [1] is a monomer represented by the following general formula [2].
General formula [2]

（一般式［２］において、Ｒ¹は水素原子、ハロゲン原子またはメチル基を表し、Ｌ²は、Ｚに結合する原子が酸素原子、窒素原子またはイオウ原子のいずれかである２価の連結基を表し、Ｚは脂環式の環状基を表す。）

(In General Formula [2], R ¹ represents a hydrogen atom, a halogen atom or a methyl group, and L ² represents a divalent linking group in which the atom bonded to Z is an oxygen atom, a nitrogen atom or a sulfur atom. Z represents an alicyclic cyclic group.)

(3) The coating composition according to (1), wherein the monomer represented by the general formula [1] is a monomer represented by the following general formula [3].
General formula [3]

（一般式［３］において、Ｒ¹は水素原子、ハロゲン原子またはメチル基を表し、Ｘ¹は酸素原子、イオウ原子または−Ｎ（Ｒ²）−を表し、Ｚ¹は脂環式の縮合環基を表す。ここで、Ｒ²は水素原子、置換されていてもよい炭素数１〜８のアルキル基、または置換されていてもよい炭素数３〜８のシクロアルキル基を表す。）

(In the general formula [3], R ¹ represents a hydrogen atom, a halogen atom or a methyl group, X ¹ represents an oxygen atom, a sulfur atom or —N (R ² ) —, and Z ¹ represents an alicyclic fused ring. R ² represents a hydrogen atom, an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted cycloalkyl group having 3 to 8 carbon atoms.)

(4) The thermal transfer ink sheet having a dye layer in which a heat transferable dye is contained in a resin binder on a support, the dye layer according to any one of (1) to (3) A thermal transfer ink sheet comprising a solid content of a coating composition.

(5) An ink cartridge filled with the thermal transfer ink sheet according to (4).

(6) A thermal transfer recording method comprising forming an image on an image receiving sheet having an ink receiving layer containing a polymer latex on a support, using the thermal transfer ink sheet described in (4).

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a thermal transfer ink sheet, an ink cartridge, a thermal transfer recording method having high sensitivity and no image defects, and a coating composition for forming a dye layer used in producing these.

Hereinafter, the present invention will be described in detail.
The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present invention, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

<Dye layer forming coating composition>
(Characteristic)
The coating composition for forming a dye layer of the present invention is used for forming a dye layer of a thermal transfer ink sheet. The heat-sensitive transfer ink sheet has at least a structure provided with a dye layer containing a heat transferable dye in a resin binder on a support. The coating composition of the present invention is characterized in that a polymer containing a repeating unit derived from a monomer represented by the following general formula [1] is selected as a resin binder and contained in combination with a heat transfer dye. It is what.

(Monomer represented by the general formula [1])
First, the monomer represented by the following general formula [1] will be described.
General formula [1]

In the general formula [1], R ¹ represents a hydrogen atom, a halogen atom or a methyl group, and L ¹ represents a single bond or a divalent linking group in which the atom bonded to Y is a hetero atom. Y represents a cyclic group.

R ¹ is preferably a hydrogen atom or a methyl group.
The hetero atom in L ¹ is preferably an oxygen atom, a sulfur atom or a nitrogen atom.
L ¹ is preferably the above divalent linking group. However, when Y is an optionally substituted heterocyclic group (particularly, the atom bonded to L ¹ is a heteroatom), L ¹ is preferably a single bond.

The cyclic group for Y may be any group as long as it has a cyclic structure. For example, the cyclic group may be an alicyclic cyclic group or an aromatic cyclic group. Further, the cyclic group may be a heterocyclic group containing a hetero atom, and the heterocyclic group may be an aromatic heterocyclic group. In addition, these cyclic groups may be condensed with another ring, for example, a ring as indicated by Y. Moreover, what forms the bridge | crosslinking type ring and what forms the spiro ring may be sufficient.
The cyclic group in Y is preferably an alicyclic cyclic group, and more preferably an alicyclic condensed ring group (cross-linked hydrocarbon ring group). The alicyclic here refers to a carbocyclic group having a structure in which carbon atoms are bonded in a ring, and does not exhibit aromaticity, and the condensed ring group is an organic group having a cyclic structure. Two or more rings are bonded by sharing two or more atoms (Chemical Dictionary, Kyoritsu Shuppan Co., Ltd.).
Examples of the ring of the cyclic group include cyclohexane ring, dicyclohexane ring, dicyclopentadiene ring, norbornene ring, isobornene ring, adamantane ring, benzene ring, naphthalene ring, biphenyl ring, pyrene ring, and the like homocyclic ring groups; Epoxy ring, oxetane ring, thiophene ring, pyrrole ring, furan ring, pyridine ring, pyrrolidine ring, piperidine ring, piperazine ring, morpholine ring, dioxane ring, quinuclidine ring, tetrahydrofuran ring, aziridine ring, dithiane ring, pyrazole ring, triazole ring Imidazole ring, oxazole ring, thiazole ring, pyridone ring, quinolone ring, indole ring, benzotriazole ring, quinoline ring, isoquinoline ring, pyridazine ring, pyrimidine ring, pyrazine ring, thiadiazole ring, isoxazole ring, isothiazole Ring, a heterocyclic ring group, such as.
The cyclic group may have a substituent.

  Examples of the substituent that the cyclic group in Y (including the above-described substituent that the phenyl group may have) include an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, a heterocyclic group, Halogen atom, cyano group, nitro group, sulfo group, carboxyl group, hydroxy group, amino group, alkylamino group, arylamino group, alkoxy group, aryloxy group, alkylthio group, arylthio group, acyl group, acylamino group, sulfonamide Group, acyloxy group, formyl group, carbamoyl group, sulfamoyl group, imide group, ureido group, urethane group, sulfonyl group, sulfinyl group and the like.

  The polymer of the present invention is a fluoroaliphatic group-containing copolymer, and the polymer includes two or more kinds of polymer units of the monomer represented by the general formula [1] as a constituent unit. Also good.

  The monomer represented by the general formula [1] used in the present invention is more preferably a monomer represented by the following general formula [2].

In the general formula [2], R ¹ has the same meaning as that in the general formula [1], and the preferred range is also the same. L ² represents a divalent linking group in which an atom bonded to Z is an oxygen atom, a nitrogen atom or a sulfur atom, and —COO—, —COS—, —CON (R ² ) — and the like are preferable. . R ² represents a hydrogen atom, an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted cycloalkyl group having 3 to 8 carbon atoms. The number of carbon atoms of the cycloalkyl group in R ² is preferably 3-8, 5-8 is more preferable. R ² is preferably a hydrogen atom or the above alkyl group. Z represents an alicyclic cyclic group, and the alicyclic cyclic group may be a monocyclic cyclic group such as a cyclohexyl group or a polycyclic cyclic group such as a bicyclohexyl group. Z is preferably the same as the range included in Y of the general formula [1].

  The monomer represented by the general formula [1] used in the present invention is more preferably a monomer represented by the following general formula [3].

In General Formula [3], R ¹ has the same meaning as in General Formula [1], and the preferred range is also the same. X ¹ represents an oxygen atom, a sulfur atom or N (R ² ) —, preferably an oxygen atom. Here, R ² represents a hydrogen atom, an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted cycloalkyl group having 3 to 8 carbon atoms, and the alkyl group or cycloalkyl group Of these, an alkyl group is preferred. R ² is preferably a hydrogen atom or an alkyl group, and the alkyl group preferably has 1 to 4 carbon atoms. Z ¹ represents a cyclic group of an alicyclic condensed ring, and an adamantyl group, norbornyl group, etc. are preferably used.

  Specific examples of the monomer represented by the general formula [1] are shown below, but the monomer that can be used in the present invention is not limited to these examples.

(Polymer of the present invention)
Next, a polymer containing a repeating unit derived from the monomer represented by the general formula [1] (hereinafter also referred to as the polymer of the present invention) will be described.
The polymer of the present invention may be a copolymer (copolymer) with another type of monomer copolymerizable with the monomer represented by the general formula [1]. There is no particular limitation on the monomer copolymerizable with the monomer represented by the general formula [1]. Monomers that can be polymerized by a normal radical polymerization method or ionic polymerization method can be used, and monomers included in the monomer groups (a) to (i) shown below can be given as suitable examples. The polymer of the present invention can be synthesized by selecting these monomers in any combination and copolymerizing them with the monomer represented by the general formula [1].

(A) Conjugated dienes 1,3-pentadiene, isoprene, 1-phenyl-1,3-butadiene, 1-α-naphthyl-1,3-butadiene, 1-β-naphthyl-1,3-butadiene, cyclopentadiene etc.

(B) Olefins Ethylene, propylene, vinyl chloride, vinylidene chloride, 6-hydroxy-1-hexene, 4-pentenoic acid, methyl 8-nonenoate, vinyl sulfonic acid, trimethylvinylsilane, trimethoxyvinylsilane, 1,4-divinyl Cyclohexane, 1,2,5-trivinylcyclohexane, etc.

(C) α, β-unsaturated carboxylic acid esters Alkyl acrylates (for example, methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, etc.), substituted alkyl acrylates (for example, benzyl acrylate, 2 -Cyanoethyl acrylate, etc.), alkyl methacrylate (eg, methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, etc.), substituted alkyl methacrylate (eg, 2-hydroxyethyl methacrylate, glycidyl methacrylate, glycerin monomethacrylate, 2- Acetoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 2-methoxyethyl Tacrylate, polypropylene glycol monomethacrylate (polyoxypropylene having an addition mole number of 2 to 100), 3-N, N-dimethylaminopropyl methacrylate, 2-carboxyethyl methacrylate, 3-sulfopropyl methacrylate, 4-oxysulfobutyl Methacrylates, 3-trimethoxysilylpropyl methacrylate, allyl methacrylate, 2-isocyanatoethyl methacrylate, etc.), derivatives of unsaturated dicarboxylic acids (eg monobutyl maleate, dimethyl maleate, monomethyl itaconate, dibutyl itaconate, etc.), many Functional esters (eg ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,4-cyclohexane diacrylate, pentaerythritol tetrameta Acrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, dipentaerythritol pentamethacrylate, pentaerythritol hexaacrylate, 1,2,4-cyclohexanetetramethacrylate, etc.).

(D) Amides of α, β-unsaturated carboxylic acids such as acrylamide, methacrylamide, N-methylacrylamide, N, N-dimethylacrylamide, N-methyl-N-hydroxyethylmethacrylamide, N-tert-butylacrylamide, N-tert-octylmethacrylamide, N-cyclohexylacrylamide, N-phenylacrylamide, N- (2-acetoacetoxyethyl) acrylamide, N-acryloylmorpholine, diacetone acrylamide, itaconic acid diamide, N-methylmaleimide, 2- Acrylamide-methylpropanesulfonic acid, methylenebisacrylamide, dimethacryloylpiperazine, etc.

(E) Unsaturated nitriles Acrylonitrile, methacrylonitrile and the like.

(F) Styrene and its derivatives Styrene, vinyl toluene, p-tert butyl styrene, vinyl benzoic acid, methyl vinyl benzoate, α-methyl styrene, vinyl naphthalene, p-hydroxymethyl styrene, p-styrene sulfonic acid sodium salt, p -Styrene sulfinic acid potassium salt, p-aminomethylstyrene, 1,4-divinylbenzene and the like.

(G) Vinyl ethers Methyl vinyl ether, butyl vinyl ether, methoxyethyl vinyl ether and the like.

(H) Vinyl esters Vinyl acetate, vinyl propionate, vinyl benzoate and the like.

(I) Other polymerizable monomers N-vinylimidazole, 4-vinylpyridine, N-vinylpyrrolidone, 2-vinyloxazoline, 2-isopropenyloxazoline, divinylsulfone, and the like.

The amount of the polymerization unit derived from the monomer represented by the general formula [1] constituting the polymer of the present invention is preferably 10% by mass to 90% by mass based on the total polymerization units constituting the polymer. It is more preferably 10% by mass to 80% by mass, and further preferably 20% by mass to 50% by mass.
The mass average molecular weight of the polymer used in the present invention is preferably from 3,000 to 500,000, more preferably from 6,000 to 300,000, and even more preferably from 8,000 to 100,000. Here, the mass average molecular weight and the molecular weight were measured by a differential refractometer detection using a GPC analyzer (solvent THF) using columns of TSKgel GMHxL, TSKgel G4000HxL, and TSKgel G2000HxL (both trade names manufactured by Tosoh Corporation). The molecular weight expressed in terms of conversion.

The polymer of the present invention can be produced by a known and conventional method. For example, it can be easily obtained by a solution polymerization method, a suspension polymerization method, an emulsion polymerization method, a dispersion polymerization method, an anionic polymerization method, a cationic polymerization or the like.
For example, it can be produced by adding a general-purpose radical polymerization initiator and polymerizing the monomer represented by the general formula [1] in an organic solvent. Or depending on the case, it can manufacture by the same method as the above, adding another addition polymerizable monomer. Depending on the polymerizability of each monomer, a dropping polymerization method in which a monomer and an initiator are added dropwise to a reaction vessel is also effective for obtaining a polymer having a uniform composition.

  Hereinafter, although the specific structural example of the polymer of this invention is shown, the polymer which can be used by this invention is not limitedly interpreted by these illustrations. In addition, the number in a formula shows the mass ratio of each monomer component. Mw represents a mass average molecular weight. In the hydrocarbon group, (t) is tertiary and represents a tertiary group, and those not particularly described represent a linear hydrocarbon group.

(Polymer that can be used in combination)
In addition to the polymer of the present invention, any polymer may be used in combination with the coating composition of the present invention. The polymer used in combination is preferably transparent or translucent and colorless, and is a natural resin, polymer and copolymer, synthetic resin, polymer and copolymer, and other film-forming media such as gelatins, polyvinyl alcohols, hydroxyethyl cellulose. , Cellulose acetates, cellulose acetate butyrate, polyvinylpyrrolidones, casein, starch, polyacrylic acids, polymethylmethacrylic acids, polyvinylchlorides, polymethacrylic acids, styrene-maleic anhydride copolymers, styrene-acrylonitrile copolymers , Styrene-butadiene copolymers, polyvinyl acetals (eg, polyvinyl formal and polyvinyl butyral), polyesters, polyurethanes, phenoxy resins Polyvinylidene chlorides, polyepoxides, polycarbonates, polyvinyl acetates, polyolefins, polyamides such.

  When based on the total amount of polymer contained in the coating composition of the present invention, the content of the polymer of the present invention is preferably 10 to 100% by mass, more preferably 10 to 90% by mass, More preferably, it is 30-80 mass%.

(Heat transfer dye)
The coating composition of the present invention contains a heat transferable dye.

  As the heat transfer dye, those required for the dye layer to be formed using the coating composition of the present invention are selected. For example, when the coating composition of the present invention is used to produce a thermal transfer recording material capable of full color image recording, a heat-transferable cyan dye capable of forming a cyan image, a magenta image can be formed. A heat-transferable magenta dye capable of forming a yellow image and a heat-transferable yellow dye capable of forming a yellow image are used.

  As the heat transfer cyan dye, for example, those described in JP-A-3-103477 and JP-A-3-150194 can be preferably used. As the heat transfer magenta dye, for example, those described in JP-A-5-286268 can be preferably used. As the heat transfer yellow dye, for example, those described in JP-A No. 1-222592 can be preferably used.

  When based on the total solid content contained in the coating composition of the present invention, the content of the heat transfer dye is preferably 10 to 90% by mass, more preferably 20 to 80% by mass, More preferably, it is 30-70 mass%.

(solvent)
The coating composition of the present invention can contain water or an organic solvent. Examples of the organic solvent that can be used in the present invention include benzene solvents such as toluene, ketone solvents such as methyl ethyl ketone, alcohol solvents such as methanol and ethanol, amide solvents such as N, N-dimethylamide, ethyl acetate, and the like. And ester solvents. The coating composition of the present invention may be a solution, an emulsion, or a dispersion.

(Other ingredients)
To the coating composition of the present invention, for example, an anti-fading agent and an ultraviolet absorber can be added as components other than those described above. The addition amount of these additives is preferably 0 to 70% by mass, more preferably 5 to 60% by mass, based on the total solid content contained in the coating composition of the present invention. More preferably, it is 10-50 mass%.

(Preparation method)
The method for preparing the coating composition of the present invention is not particularly limited. For example, the polymer of the present invention and the heat transferable dye may be mixed and then added to the solvent and stirred, or the polymer of the present invention and the heat transferable dye may be separately added to the solvent in advance. It may be prepared by mixing them afterwards. Moreover, you may add an additive in any step of these processes.

<Thermal transfer ink sheet>
(Features and manufacturing method)
The thermal transfer ink sheet of the present invention includes a dye layer containing a heat transferable dye in a polymer (resin binder) containing a repeating unit derived from the monomer represented by the general formula [1] on a support. At least.
The heat-sensitive transfer ink sheet of the present invention comprises a coating composition of the present invention containing a polymer containing a repeating unit derived from a monomer represented by the general formula [1] and a heat-transferable dye on a support. And it can manufacture by drying suitably and forming a dye layer. The dye layer contains the solid content of the coating composition of the present invention.

(Support)
As the support for the heat-sensitive transfer ink sheet of the present invention, any conventionally used support for an ink sheet can be appropriately selected and used. For example, the material described in paragraph No. 0050 of JP-A-7-137466 can be preferably used. The thickness of the support is preferably 2 to 30 μm.

(Dye layer)
When the present invention is applied to a thermal transfer recording material capable of full color image recording, a cyan ink sheet containing a heat transferable cyan dye capable of forming a cyan image, and a heat transferability capable of forming a magenta image. It is preferable that a magenta ink sheet containing a magenta dye and a yellow ink sheet containing a heat transferable yellow dye capable of forming a yellow image are sequentially coated on a support. Further, if necessary, an ink sheet containing a black image forming substance may be further formed.
The content of the dye in the dye layer is preferably ^{0.03~1.0g / m 2, 0.1~0.6g / m} 2 is more preferable. Moreover, 0.2-5 micrometers is preferable and, as for the thickness of a dye layer, 0.4-2 micrometers is more preferable.

(Other layers)
The thermal transfer ink sheet of the present invention may have a layer other than the dye layer on the support as long as the effect of the present invention is not excessively inhibited. For example, an intermediate layer may be provided between the support and the dye layer, or a back layer may be provided on the support surface opposite to the dye layer (hereinafter also referred to as “back surface”). May be. Examples of the intermediate layer include an undercoat layer and a diffusion prevention layer (hydrophilic barrier layer) for preventing diffusion of the dye in the direction of the support. Moreover, as a back layer, a heat resistant slip layer can be mentioned, for example, and adhesion of the thermal head to the ink sheet can be prevented.

<Ink cartridge>
The thermal transfer ink sheet of the present invention can be loaded in an ink cartridge. As the structure and loading method of the ink cartridge, those conventionally used in the field of thermal transfer recording can be used. Specifically, the ink cartridge techniques described in Japanese Utility Model Laid-Open No. 63-161851, Japanese Utility Model Laid-Open No. 63-161851 and Japanese Utility Model Laid-Open No. 1-1101864 can be preferably applied to the present invention. . In particular, the technique described in Japanese Utility Model Laid-Open No. 1-1101864 can be preferably applied according to the present invention.

<Thermal transfer recording>
When performing thermal transfer recording using the thermal transfer ink sheet of the present invention, a heating means such as a thermal head and an image receiving sheet are used in combination. That is, in a state where the ink sheet and the image receiving sheet are overlapped, thermal energy is applied from the thermal head to the ink sheet according to the image recording signal, and the dye in the portion to which the thermal energy is applied moves to the image receiving sheet and is fixed. Thus, image recording is performed.
In recent years, it is necessary to perform such image recording at higher speed. Examples of models capable of performing high-speed image recording include a sublimation printer ASK2000 (trade name) manufactured by Nidec Copal and a sublimation printer Picture Maker G4 (trade name) manufactured by Eastman Kodak. The thermal transfer ink sheet of the present invention does not cause image defects with high sensitivity even when these are used for high-speed image recording.

<Image receiving sheet>
(Construction)
Next, an image receiving sheet used in combination with the ink sheet of the present invention will be described.
The image receiving sheet has a structure in which a dye receiving layer (receiving layer) is formed on a support. A base layer is preferably formed between the receptor layer and the support. For example, a white background adjustment layer, a charge adjustment layer, an adhesive layer, and a primer layer are formed. Moreover, it is preferable that the heat insulation layer is formed between the base layer and the support body. Each layer between the support and the receiving layer is simply referred to as an “intermediate layer” and includes the above-described underlayer and heat insulating layer. The image receiving sheet preferably has at least one intermediate layer in addition to at least one receiving layer. It is preferable that a curl adjusting layer, a writing layer, and a charge adjusting layer are formed on the back side of the support.

(Receptive layer)
The receiving layer serves to receive the dye transferred from the ink sheet and maintain the formed image.
Therefore, a resin (dyeable receiving polymer) that is easily dyed is used for the receiving layer.
For example, polyolefin resins such as polyethylene and 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 Resin, polyamide resin, polycarbonate, phenol resin, polyurethane, epoxy resin, polysulfone, butyral resin, melamine resin, polyvinyl alcohol, copolymers of olefins such as ethylene and propylene with other vinyl monomers, vinyl chloride vinyl acetate copolymer, A single substance or a mixture of styrene acrylic copolymer, ionomer, cellulose resin, natural rubber, synthetic rubber and the like can be used, but is not limited thereto. It is preferable that the receiving polymer used in the receiving layer is made into a latex.

(Polymer latex)
In the image-receiving sheet, the polymer latex that can be used in the receiving layer is obtained by dispersing a hydrophobic polymer insoluble in water as fine particles in a water-soluble dispersion medium. As the dispersion state, the polymer is emulsified in a dispersion medium, the emulsion is polymerized, the micelle is dispersed, or the polymer molecule has a partially hydrophilic structure and the molecular chain itself is molecularly dispersed. Any of things may be used. For polymer latex, Tadashi Okuda, Hiroshi Inagaki, “Synthetic Resin Emulsion”, published by Kobunshi Publishing (1978), Takaaki Sugimura, Ikuo Kataoka, Junichi Suzuki, Keiji Kasahara, “Application of Synthetic Latex”, Takashi Published by Molecular Publications (1993), Soichi Muroi, “Chemistry of Synthetic Latex”, published by High Polymers Publications (1970), supervised by Yoshiaki Mitsuzawa, “Development and Application of Water-Based Coating Materials”, CMC Publishing ( 2004) and JP-A-64-538. The average particle size of the dispersed particles is preferably 1 to 50000 nm, and more preferably 5 to 1000 nm. The particle size distribution of the dispersed particles is not particularly limited, and may have a wide particle size distribution or a monodispersed particle size distribution.

  The polymer latex used in the present invention may be a normal uniform structure polymer latex or a so-called core / shell type latex. When the latter is employed, it may be preferable to change the glass transition temperature between the core and the shell. The glass transition temperature of the polymer latex used in the present invention is preferably −30 ° C. to 130 ° C., more preferably 0 ° C. to 100 ° C., further preferably 10 ° C. to 80 ° C.

  For the polymer latex, it is preferable to use hydrophobic polymers such as acrylic polymers, polyesters, rubbers (for example, SBR resin), polyurethanes, polyvinyl chlorides, polyvinyl acetates, polyvinylidene chlorides, polyolefins and the like. it can. These polymers may be linear polymers, branched polymers, cross-linked polymers, so-called homopolymers in which a single monomer is polymerized, or two or more types of monomers are polymerized. It may be a copolymer. In the case of a copolymer, it may be a random copolymer or a block copolymer. The molecular weight of these polymers is preferably 5,000 to 1,000,000 in terms of number average molecular weight, and more preferably 10,000 to 500,000. If the molecular weight is too small, the mechanical strength of the layer containing the latex is insufficient, and if it is too large, the film formability is poor and this is not preferred. In the present invention, a crosslinkable polymer latex is also preferably used.

  There is no restriction | limiting in particular about the monomer used for the synthesis | combination of polymer latex. Monomers that can be polymerized by a normal radical polymerization method or ionic polymerization method can be used, and the monomer groups (a) to (i) can be preferably used. Specific examples of the monomer group (c) include 2-chloroethyl acrylate and chloro-3-N, N, N-trimethylammoniopropyl methacrylate, specific examples of the monomer group (f) include p-chloromethylstyrene, and the monomer group. As a specific example of (h), vinyl salicylate and vinyl chloroacetate can also be added. Furthermore, α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, sodium acrylate, ammonium methacrylate, potassium itaconic acid, and salts thereof can also be added as a good monomer group. . Polymer monomers can be prepared by selecting these monomers in any combination.

  Polymer latex is also commercially available, and the following polymers can be used in the present invention. Examples of acrylic polymers include Sebian A-4635, 4718, 4601 manufactured by Daicel Chemical Industries, Ltd., Nipol Lx811, 814, 821, 820, 855 (P-17: Tg36 ° C.) manufactured by Zeon Corporation, 857x2. (P-18: Tg43 ° C), Dainippon Ink Chemical Co., Ltd. Voncoat R3370 (P-19: Tg25 ° C), 4280 (P-20: Tg15 ° C), Nippon Pure Chemical Co., Ltd. Jurimer ET-410 ( P-21: Tg44 ° C), JSR AE116 (P-22: Tg50 ° C), AE119 (P-23: Tg55 ° C), AE121 (P-24: Tg58 ° C), AE125 (P-25: Tg60) ° C), AE134 (P-26: Tg48 ° C), AE137 (P-27: Tg48 ° C), AE140 (P-28: Tg53 ° C), AE173 (P-29: Tg60 ° C), Aaron manufactured by Toagosei Co., Ltd. A-104 (P-30: Tg45 ° C), NS-600X, NS-620X, manufactured by Takamatsu Yushi Co., Ltd., Vinibrand 2580, 2583, 2641, 2770, 2770H, 2635, 2886, 5202C manufactured by Nissin Chemical Industry Co., Ltd. , 2706, etc. (all are trade names).

  Examples of polyesters include FINETEX ES650, 611, 675, 850 manufactured by Dainippon Ink Chemical Co., Ltd., WD-size, WMS manufactured by Eastman Chemical, A-110, A-115GE manufactured by Takamatsu Yushi Co., Ltd., A- 120, A-121, A-124GP, A-124S, A-160P, A-210, A-215GE, A-510, A-513E, A-515GE, A-520, A-610, A-613, A-615GE, A-620, WAC-10, WAC-15, WAC-17XC, WAC-20, S-110, S-110EA, S-111SL, S-120, S-140, S-140A, S- 250, S-252G, S-250S, S-320, S-680, DNS-63P, NS-122L, NS-122LX, NS-244LX, NS-140L, NS-141LX, NS-282LX, Toagosei Co., Ltd. Aronmelt PES-1000 series, PES-2000 series, Vironal MD-1100, MD-1200, MD-1220, MD-1245, MD-1250, MD-1335, MD-1400, MD-1480 , MD-1500, MD-1930, MD-1985, Sepuljon ES manufactured by Sumitomo Seika Co., Ltd. (all are trade names).

  Examples of polyurethanes include Dainippon Ink Chemical Co., Ltd.HYDRAN AP10, AP20, AP30, AP40, 101H, Vondic 1320NS, 1610NS, Dainichi Seika Co., Ltd.D-1000, D-2000, D-6000, D-4000, D-9000, Takamatsu Yushi Co., Ltd. NS-155X, NS-310A, NS-310X, NS-311X, Daiichi Kogyo Seiyaku Co., Ltd. Elastron etc. (all are trade names).

  Examples of rubbers include LACSTAR 7310K, 3307B, 4700H, 7132C (above, manufactured by Dainippon Ink and Chemicals), Nipol Lx416, LX410, LX430, LX435, LX110, LX415A, LX438C, 2507H, LX303A, LX407BP series, V1004, MH5055 (made by Nippon Zeon Co., Ltd.), etc. (all are trade names).

  Examples of polyvinyl chlorides include: Z351, G351, G576, Nissin Chemical Industry Co., Ltd., Vinibrand 240, 270, 277, 375, 386, 609, 550, 601, 602, 630, 660, 671, 683, 680, 680S, 681N, 685R, 277, 380, 381, 410, 430, 432, 860, 863, 865, 867, 900, 900GT, 938, 950, etc. (all are trade names). Examples of polyvinylidene chlorides include L502 and L513 manufactured by Asahi Kasei Kogyo Co., Ltd., and D-5071 manufactured by Dainippon Ink & Chemicals, Inc. (all are trade names). Examples of polyolefins include Chemipearl S120, SA100, V300 (P-40: Tg80 ° C) manufactured by Mitsui Petrochemical Co., Ltd., Voncoat 2830, 2210, 2960 manufactured by Dainippon Ink Chemical Co., Ltd., Sumitomo Seika Co., Ltd. Examples of Zyxen, Sepoljon G, and copolymerized nylons include Sepoljon PA manufactured by Sumitomo Seika Co., Ltd. (all are trade names).

  Examples of polyvinyl acetates include Nishin Chemical Industry Co., Ltd.ViniBran 1080, 1082, 1085W, 1108W, 1108S, 1563M, 1566, 1570, 1588C, A22J7-F2, 1128C, 1137, 1138, A20J2, A23J1, A23J1, A23K1, A23P2E, A68J1N, 1086A, 1086, 1086D, 1108S, 1187, 1241LT, 1580N, 1083, 1571, 1572, 1581, 4465, 4466, 4468W, 4468S, 4470, 4485LL, 4495LL, 1023, 1042, 1060, 1060S, 1080M, 1084W, 1084S, 1096, 1570K, 1050, 1050S, 3290, 1017AD, 1002, 1006, 1008, 1107L, 1225, 1245L, GV-6170, GV-6181, 4468W, 4468S, etc. Product name).

  These polymer latexes may be used alone or in combination of two or more as required.

  Although the specific structural example of the polymer which comprises a polymer latex is shown below, the polymer latex which can be used by this invention is not limitedly interpreted by the following illustrations. In addition, the number in a formula shows the mass ratio of each monomer component, and Mw represents a mass mean molecular weight.

  Hereinafter, the features of the present invention will be described more specifically with reference to Examples and Comparative Examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

<Example 1>
(1) Polymer synthesis A reactor equipped with a stirrer and a reflux condenser was charged with 24 g of monomer A-1, 16 g of methyl acrylate, 0.28 g of dimethyl 2,2′-azobisisobutyrate, and 2-butanone. 30 g was added and heated to 78 ° C. for 6 hours under a nitrogen atmosphere to complete the reaction. The obtained polymer AP-1 had a mass average molecular weight of 7.0 × 10 ⁵ .
For the polymer AP-9, the polymer AP-15, the polymer AP-25, and the polymer AP-34, the synthesis was performed in the same manner as the synthesis of the polymer AP-1.

(2) Preparation of Ink Sheet (2-1) Preparation of Sample 101 (Invention) A polyester film (Lumirror, trade name, manufactured by Toray Industries, Inc.) having a thickness of 6.0 μm was used as a base film. A heat-resistant slip layer (thickness 1 μm) is formed on the back side of the film, and a yellow ink composition, a magenta ink composition, and a cyan ink composition having the following composition are applied to each surface in a single color (application during dry film formation) Amount 1 g / m ² ).

Yellow Ink Composition Dye (Macrolex Yellow 6G, trade name, manufactured by Bayer) 5.5 parts by mass Polymer AP-1 4.5 parts by mass Methyl ethyl ketone / toluene (mass ratio 1/1) 90 parts by mass

Magenta ink composition Magenta dye (Disperse Red 60) 5.5 parts by mass Polymer AP-1 4.5 parts by mass Methyl ethyl ketone / toluene (mass ratio 1/1) 90 parts by mass

Cyan ink composition Cyan dye (Disperse Red 63) 5.5 parts by mass Polymer AP-1 4.5 parts by mass Methyl ethyl ketone / toluene (mass ratio 1/1) 90 parts by mass

(2-2) Preparation of Sample 102 (Invention) Sample 102 of the invention was prepared in the same manner as the preparation of Sample 101 except that the polymer AP-1 contained in each ink composition was changed to the polymer AP-9. did.

(2-3) Preparation of Sample 103 (Invention) Sample 103 of the invention was prepared in the same manner as Sample 101 except that polymer AP-1 contained in each ink composition was changed to polymer AP-15. did.

(2-4) Preparation of Sample 104 (Invention) Sample 104 of the invention was prepared in the same manner as Sample 101 except that the polymer AP-1 contained in each ink composition was changed to the polymer AP-25. did.

(2-5) Preparation of Sample 105 (Invention) Sample 105 of the invention was prepared in the same manner as Sample 101 except that the polymer AP-1 contained in each ink composition was changed to the polymer AP-34. did.

(2-6) Production of Sample 106 (Comparative Example) A polyester film (Lumirror, trade name, manufactured by Toray Industries, Inc.) having a thickness of 6.0 μm was used as a base film. A heat-resistant slip layer (thickness 1 μm) is formed on the back side of the film, and a yellow ink composition, a magenta ink composition, and a cyan ink composition having the following composition are applied to each surface in a single color (application during dry film formation) Amount 1 g / m ² ).

Yellow Ink Composition Dye (Macrolex Yellow 6G, trade name, manufactured by Bayer) 5.5 parts by weight Polyvinyl butyral 4.5 parts by weight (ESREC BX-1, trade name, manufactured by Sekisui Chemical Co., Ltd.)
90 parts by mass of methyl ethyl ketone / toluene (mass ratio 1/1)

Magenta ink composition Magenta dye (Disperse Red 60) 5.5 parts by mass Polyvinyl butyral 4.5 parts by mass (ESREC BX-1, trade name, manufactured by Sekisui Chemical Co., Ltd.)
90 parts by mass of methyl ethyl ketone / toluene (mass ratio 1/1)

Cyan ink composition Cyan dye (Disperse Red 63) 5.5 parts by mass Polyvinyl butyral 4.5 parts by mass (ESREC BX-1, trade name, manufactured by Sekisui Chemical Co., Ltd.)
90 parts by mass of methyl ethyl ketone / toluene (mass ratio 1/1)

(2-7) Preparation of Sample 107 (Comparative Example) An ink sheet of Example 1 described in Japanese Patent No. 3207518 was prepared.

(3) Preparation of image-receiving sheet 1 The paper support surface laminated on both sides with polyethylene was subjected to corona discharge treatment, and then a gelatin subbing layer containing sodium dodecylbenzenesulfonate was provided. Further, an intermediate layer A forming coating solution having the following composition was applied by a bar coater and dried, and then a receiving layer A forming coating solution having the following composition was applied by a bar coater and dried. Bar coater coating was performed at 40 ° C., and drying was performed at 50 ° C. for 16 hours for each layer. The coating amount at the time of each dry, intermediate layer A is 1.0 g / m ^2, the receiving layer A was performed coated to a 3.1 g / m ^2. The produced image receiving sheet was used as an image receiving sheet 1 for image formation described later.

Coating solution for forming intermediate layer A Polyester resin (Byron 200, trade name, manufactured by Toyobo Co., Ltd.) 10 parts by weight Optical brightener (Uvitex OB, trade name, manufactured by Ciba Geigy) 1 part by weight Titanium oxide 30 parts by weight Methyl ethyl ketone / Toluene (mass ratio 1/1) 90 parts by mass

Receptor layer A forming coating solution 100 parts by mass of polyester resin (resin described in Example 1 of JP-A-2-265789)
Amino-modified silicone 5 parts by mass (manufactured by Shin-Etsu Chemical Co., Ltd., trade name, X-22-3050C)
Epoxy-modified silicone 5 parts by mass (manufactured by Shin-Etsu Chemical Co., Ltd., trade name, X-22-300E)
Methyl ethyl ketone / toluene (mass ratio 1/1) 400 parts by mass

(4) Image formation The above ink sheet and image receiving sheet 1 are processed so that they can be loaded into a sublimation printer ASK2000 (trade name) manufactured by Nidec Copal, and the maximum density can be obtained in the high-speed print mode. A black solid image was output.

(5) Evaluation (5-1) Relative Transfer Density Evaluation Visual density of a black image obtained under the above conditions was measured with a Photographic Densitometer (manufactured by X-Rite incorporated). Table 1 below shows relative values when the transfer density of the sample 106 is 100.

(5-2) Evaluation of ink fusing property The ink fusing property was determined by evaluating the fusing state in the print portion where the Dmax of the image was obtained according to the following criteria. The obtained results are shown in Table 1 below.
5: The image receiving sheet peels off smoothly from the ink sheet, and the ink
No fusion (sticking) is observed.
4: The fusion area is 1% or less of the printed area of the density area where fusion occurred.
there were.
3: The fused area exceeds 1% of the screen area of the density area where fusion occurred.
It was 10% or less.
2: The fused area exceeds 10% of the printed area of the density area where fusion occurred.
It was 20% or less.
1: The fusion area exceeds 20% of the screen area of the density area where fusion occurred.
Yeah.

(5-3) Evaluation of background contamination The thermal transfer ink sheet and the image receiving sheet 1 are superposed so that the dye layer and the receiving layer are in contact with each other, and the thermal roll laminator is adjusted so that the surface temperature of the thermal transfer ink sheet becomes 68 ° C. Then, the concentration of the dye transferred to the receiving layer was measured with a Photographic Densitometer (manufactured by X-Rite incorporated), and the change rate (ΔD) of the concentration before and after the test was calculated.

As is apparent from the results in Table 1 above, the sample 106 showed ink fusion due to high-speed transfer recording. In Sample 107, although the ink fusing property was improved, the background stain was also reduced.
It was found that all of the samples 101 to 105 according to the present invention had no ink fusing and suppressed scumming. Thus, by using the polymer of the present invention, a heat-sensitive transfer ink sheet having high sensitivity and no surface defects could be obtained.

<Example 2>
Image formation and testing were performed in the same manner as in Example 1 except that the image receiving sheet 1 was replaced with the image receiving sheet 2 described below.

(1) Preparation of image-receiving sheet 2 The paper support surface laminated on both sides with polyethylene was subjected to corona discharge treatment, and then a gelatin subbing layer containing sodium dodecylbenzenesulfonate was provided. Furthermore, by the method illustrated in FIG. 9 described in US Pat. No. 2,761,791, the coating solution for forming the intermediate layer B and the coating solution for forming the receiving layer B having the following compositions are applied from the support side. Multi-layer coating was performed in the state of being laminated in this order. Immediately after coating, the film was dried at 50 ° C. for 16 hours. The coating amount at the time of each dry, intermediate layer B is 15 g / m ^2, the receiving layer B was performed coated to a 3.1 g / m ^2.

Coating liquid for forming intermediate layer B Hollow polymer latex 563 parts by mass (MH5055, trade name, manufactured by Nippon Zeon Co., Ltd.)
(Aqueous dispersion of hollow structure polymer with outer diameter of 0.5 μm)
120 parts by weight of gelatin

48 parts by mass of coating solution for receiving layer B forming polymer P-9 (Vinyl Blanc 609, trade name, manufactured by Nissin Chemical Industry Co., Ltd.)
Benzotriazole-based UV absorber polymer latex 15 parts by mass (ULS1700, trade name, manufactured by Otsuka Kogyo Co., Ltd.)
Montanic acid wax (J537, trade name, manufactured by Chukyo Yushi Co., Ltd.) 10 parts by mass

(2) Evaluation When image formation was performed using the image receiving sheet 2 in the same manner as in Example 1, the results shown in Table 2 below were obtained. None of the samples according to the present invention had ink fusion, and the relative transfer density showed a tendency of higher transfer density than in Example 1.

  By using the thermal transfer ink sheet, the ink cartridge, and the thermal transfer recording method of the present invention, it is possible to form a high-sensitivity and defect-free image even when high-speed transfer is performed. Moreover, if the coating composition of this invention is used, the dye layer of the thermal transfer ink sheet which has such a function can be simply coated. Therefore, the industrial applicability of the present invention is high in the present age when the speed of thermal transfer is increasing.

Claims (6)

A coating composition for forming a dye layer of a thermal transfer ink sheet, comprising a heat transfer dye and a polymer containing a repeating unit derived from a monomer represented by the following general formula [1].
General formula [1]

(In the general formula [1], R ¹ represents a hydrogen atom, a halogen atom or a methyl group, L ¹ represents a single bond or a divalent linking group in which the atom bonded to Y is a hetero atom, and Y represents a cyclic group. Represents a group.) The coating composition according to claim 1, wherein the monomer represented by the general formula [1] is a monomer represented by the following general formula [2].
General formula [2]

(In the general formula [2], R ¹ represents a hydrogen atom, a halogen atom or a methyl group, and L ² represents a divalent linking group in which the atom bonded to Z is an oxygen atom, a nitrogen atom or a sulfur atom. Z represents an alicyclic cyclic group.) The coating composition according to claim 1, wherein the monomer represented by the general formula [1] is a monomer represented by the following general formula [3].
General formula [3]

(In General Formula [3], R ¹ represents a hydrogen atom, a halogen atom or a methyl group, X ¹ represents an oxygen atom, a sulfur atom or —N (R ² ) —, and Z ¹ represents an alicyclic fused ring. R ² represents a hydrogen atom, an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted cycloalkyl group having 3 to 8 carbon atoms.)   In the thermal transfer ink sheet which has a dye layer in which a heat transferable dye is contained in a resin binder on a support, the dye layer is a solid of the coating composition according to any one of claims 1 to 3. A heat-sensitive transfer ink sheet comprising:   An ink cartridge filled with the thermal transfer ink sheet according to claim 4.   A thermal transfer recording method comprising forming an image on an image receiving sheet having an ink receiving layer containing a polymer latex on a support, using the thermal transfer ink sheet according to claim 4.