JP4554538B2 - Image forming method using thermal transfer system - Google Patents

Description

  The present invention relates to an image forming method using a thermal transfer method that can form an image having high density, high image quality, and excellent fastness.

  Conventionally, various thermal transfer recording methods are known. Among them, the dye diffusion transfer recording method is attracting attention as a process capable of producing a color hard copy closest to the image quality of a silver salt photograph (for example, Non-Patent Document 1 and 2). In addition, it has the advantages of being dry compared to silver halide photography, being directly visible from digital data, and being easy to duplicate.

  In this dye diffusion transfer recording system, a thermal transfer sheet containing a pigment (hereinafter also referred to as an ink sheet) and a thermal transfer image receiving sheet (hereinafter also referred to as an image receiving sheet) are superposed, and then heat is generated by an electrical signal. By heating the ink sheet with a controlled thermal head, the dye in the ink sheet is transferred to the image receiving sheet to record image information. By recording three colors of cyan, magenta, and yellow in an overlapping manner, A color image having a continuous change in color shading can be transferred and recorded.

In order to protect the image formed by the dye diffusion transfer recording method in this way, a thermal transfer cover film is used. It is known that the heat-sensitive adhesive layer of the heat-sensitive transfer cover film contains an ultraviolet absorber, an antioxidant, a fluorescent whitening agent, and the like (for example, Patent Document 1). It is also known that a heat-sensitive transfer image-receiving sheet contains a hollow plastic pigment (for example, Patent Document 2). However, the robustness of the obtained image is not always sufficient, and further improvement in image quality has been demanded.
JP 2000-108522 A JP-A-2-89690 “New development of information recording (hard copy) and its materials”, published by Toray Research Center, Inc., 1993, p. 241-285 “Development of Printer Materials”, issued by CMC Co., Ltd., 1995, p. 180

  An object of the present invention is to provide an image forming method using a thermal transfer method, which is capable of forming an image having high density, high image quality and excellent fastness. To do.

As a result of intensive studies, the present inventors have found that the above problems can be achieved by the following configuration.
(1) A heat-sensitive transfer in which a transparent resin layer is detachably provided on a base film, and a heat-sensitive adhesive layer is further provided thereon, and the transparent resin layer or the heat-sensitive adhesive layer contains an ultraviolet absorber. A heat-sensitive transfer image-receiving sheet provided on a support with a cover film and at least one receptor layer containing a polymer latex of at least two types of vinyl chloride acrylic copolymers having different chemical structures of monomers in the acrylic part and a water-soluble polymer Are heated so that the heat-sensitive adhesive layer of the heat-sensitive transfer cover film and the receiving layer of the heat-sensitive transfer image-receiving sheet face each other, and are heated by a thermal head from the base film side of the heat-sensitive transfer cover film. The transparent resin layer is transferred and adhered to the heat-sensitive transfer image-receiving sheet, and the transparent resin layer other than the heated portion is transferred to the heat-sensitive transfer image-receiving sheet together with the base film. Image forming method characterized by comprising the steps of al peeling.
( 2 ) The image forming method according to ( 1 ), wherein the heat-sensitive adhesive layer contains a resin having a glass transition temperature of 40 to 75 ° C.
( 3 ) The image forming method according to (1) or (2) , wherein the water-soluble polymer in the receiving layer is gelatin.
( 4 ) The non-foamed hollow polymer in which the thermal transfer image-receiving sheet is formed of a polystyrene resin, an acrylic resin or a styrene-acrylic resin with a particle size of 0.1 to 2 μm between the support and the receiving layer. The image forming method according to any one of (1) to ( 3 ), wherein the image forming method comprises:
( 5 ) The image forming method according to ( 4 ), wherein the heat insulating layer contains a water-soluble polymer.
( 6 ) The image forming method as described in ( 4 ) or ( 5 ), wherein the heat insulating layer contains gelatin. ( 7 ) The transparent resin layer contains a resin selected from a polyester resin, a polystyrene resin, an acrylic resin, a polyurethane resin, an acrylic urethane resin, and a silicone-modified resin of each of these resins (1) The image forming method according to any one of to ( 6 ).
( 8 ) The heat-sensitive adhesive layer contains a resin selected from acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride / vinyl acetate copolymer resin and polyester resin (1) The image forming method according to any one of to ( 7 ).
( 9 ) The image forming method according to any one of (1) to ( 8 ), wherein the heat-sensitive transfer image-receiving sheet further contains an emulsified dispersion.
( 10 ) The image forming method according to any one of (1) to ( 8 ), wherein the receiving layer further contains an emulsified dispersion.
( 11 ) The image forming method as described in any one of ( 4 ) to ( 10 ), wherein the heat insulating layer further contains an emulsified dispersion.
( 12 ) The image forming method as described in any one of ( 9 ) to ( 11 ), wherein the emulsified dispersion contains an image fastening agent or an ultraviolet absorber.

  According to the image forming method of the present invention, an image having high density, high image quality, and excellent fastness can be formed. In particular, if a heat-sensitive transfer image-receiving sheet in which a receiving layer is formed with an aqueous coating solution containing a water-soluble polymer or the like for the purpose of imparting high-speed coating suitability is used as a transfer target, a water-soluble polymer or the like contained in the receiving layer Since light fastness that is reduced by the influence of the additive can be compensated, it is possible to achieve both high-speed coating suitability and light fastness of the formed image.

  Hereinafter, an image forming method using the thermal transfer system of 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 specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

(1) Thermal transfer cover film First, the thermal transfer cover film used in the image forming method of the present invention will be described.
(Basic configuration)
Heat-sensitive transfer cover film used in the present invention, a transparent resin layer on a substrate film is provided peelably, Ri further name provided sensitive thermal adhesive layer thereon and the transparent resin layer or said It is a heat- sensitive transfer cover film containing a UV absorber in the heat-sensitive adhesive layer (hereinafter referred to as the heat-sensitive transfer cover film of the present invention). The heat-sensitive adhesive layer is preferably made of a resin having a glass transition temperature of 40 to 75 ° C. A release layer may be provided between the base film and the transparent resin layer in order to reduce the adhesiveness between the transparent resin layer and the base film and facilitate the transfer of the transparent resin layer. Further, a back layer may be provided on the back surface of the base film in order to prevent the thermal head of the printer from sticking.

(Base film)
The base film constituting the heat-sensitive transfer cover film is not particularly limited. For example, thin paper such as glassine paper, condenser paper, paraffin paper, and polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride, Examples thereof include plastics such as polystyrene, nylon, polyimide, polyvinylidene chloride, and ionomer, or a base film obtained by combining these with the paper. The thickness of the base film used for the heat-sensitive transfer cover film can be appropriately changed depending on the material so that the strength, heat resistance and the like are appropriate, but it is preferably 3 to 100 μm.

(Transparent resin layer)
The transparent resin layer provided on the base film is made of various resins excellent in friction resistance, chemical resistance, transparency, hardness, etc., for example, polyester resin, polystyrene resin, acrylic resin, polyurethane resin, acrylic urethane resin. And silicone-modified resins of these resins and mixtures of these resins. Although these resins are excellent in transparency, they tend to form a relatively tough film, so the film breakage at the time of transfer is not sufficient, so these transparent resins are silica, alumina, calcium carbonate, You may add highly transparent microparticles | fine-particles, such as a plastic pigment, a wax, etc. to such an extent that the transparency of resin is not impaired.

  As a method of forming a transparent resin layer on a base film or a release layer previously provided thereon, gravure coating, gravure reverse coating, roll coating, and many other methods of applying and drying ink containing the above resin Etc. The thickness of the transparent resin layer is preferably about 0.1 to 20 μm.

  Further, when forming the transparent resin layer, the transparent resin layer contains an additive such as a lubricant, an ultraviolet absorber, an antioxidant and / or a fluorescent brightening agent, thereby improving the resistance of various images to be coated. Scratch property, gloss, light resistance, weather resistance, whiteness, etc. can be improved.

(Peeling layer)
Prior to the formation of the transparent resin layer, the release layer that may be formed on the surface of the base film is preferably formed from a release agent such as waxes, silicone wax, silicone resin, fluororesin, and acrylic resin. The formation method may be the same as the formation method of the transparent resin layer, and a thickness of about 0.05 to 5 μm is sufficient. In addition, when it is preferable to provide a matte protective layer after the transfer, it is possible to include various particles in the release layer, or to use a base film in which the release layer side surface has been matted, It can also be.

(Thermosensitive adhesive layer)
Furthermore, a heat-sensitive adhesive layer is provided on the surface of the transparent resin layer in order to improve the transferability of the transparent resin layer and the like. The heat-sensitive adhesive layer preferably contains an ultraviolet absorber. The thermosensitive adhesive layer is preferably a thermoplastic resin having a Tg of 40 to 75 ° C., more preferably 60 to 70 ° C. (for example, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride / vinyl acetate copolymer resin). By applying and drying a solution of a resin having good adhesiveness when heated (such as a polyester resin), a thickness of about 0.1 to 10 μm is preferably formed.

  When the Tg of the heat-sensitive adhesive layer is less than 40 ° C., the adhesion between the coated image and the transparent resin layer may be insufficient, and the formed image is used at a relatively high temperature. In some cases, the softening of the adhesive layer may cause fine cracks in the transparent resin layer, resulting in poor chemical resistance, particularly plasticizer resistance. On the other hand, if the Tg exceeds 75 ° C., the transferability of the transparent protective layer may be insufficient by heating with a thermal head, and the foil breakability of the transparent resin layer may be reduced, resulting in transfer with good resolution. It can be difficult.

  Of the above heat-sensitive adhesives, particularly preferred are polyvinyl chloride resins, polyvinyl acetate resins, and vinyl chloride / vinyl acetate copolymer resins having a degree of polymerization of 50 to 300, more preferably 50 to 250. When the degree of polymerization is less than 50, the same inconvenience as when Tg is low may occur. On the other hand, when the degree of polymerization exceeds 300, the same inconvenience as when Tg is high may occur.

  The above is the configuration of the heat-sensitive transfer cover film used in the present invention. The transparent resin layer of the heat-sensitive transfer cover film may be provided alone on the base film, or a dye layer containing a diffusion transfer dye (for example, sublimation). Naturally, it may be provided in the surface order with the mold dye layer or wax ink layer. When a pigment layer containing a diffusion transfer dye is provided, the thermal transfer cover film of the present invention also functions as an ink sheet.

(UV absorber)
Below, the ultraviolet absorber used by this invention is demonstrated.
In the present invention, the ultraviolet absorber is contained in the transparent resin layer or the heat-sensitive adhesive layer.
As the ultraviolet absorber, compounds having various ultraviolet absorber skeletons widely known in the field of information recording can be used. Specific examples include 2-hydroxybenzotriazole type ultraviolet absorbers, 2-hydroxybenzotriazine type ultraviolet absorbers, and compounds having a 2-hydroxybenzophenone type ultraviolet absorber skeleton. A compound having a benzotriazole type or triazine skeleton is preferable from the viewpoint of ultraviolet absorption ability (absorption coefficient) / stability, and a compound having a benzotriazole type or benzophenone type skeleton is preferable from the viewpoint of increasing the molecular weight or forming a latex. Specifically, an ultraviolet absorber described in JP 2004-361936 A can be used.

  The ultraviolet absorber preferably has absorption in the ultraviolet region and does not have an absorption edge in the visible region. Specifically, when a thermal transfer image-receiving sheet is formed by adding to the receiving layer, the reflection density at 370 nm is preferably Abs 0.5 or more, and the reflection density at 380 nm is more preferably Abs 0.5 or more. . The reflection density at 400 nm is preferably Abs 0.1 or less. A high reflection density in the range exceeding 400 nm is not preferable because the image is yellowed.

  In the present invention, the ultraviolet absorber may have a high molecular weight. In this case, a mass average molecular weight of 10,000 or more is preferable, and a mass average molecular weight of 100,000 or more is more preferable. As a means for increasing the molecular weight, it is preferable to graft an ultraviolet absorber onto the polymer. The polymer that becomes the main chain preferably has a polymer skeleton that is inferior in dyeability to the dye used in combination. Moreover, it is preferable to have sufficient film strength when the film is formed. The graft ratio of the ultraviolet absorber to the polymer main chain is preferably 5 to 20% by mass, and more preferably 8 to 15% by mass.

Moreover, the polymer containing the unit (ultraviolet absorber unit) having ultraviolet absorbing ability may be a latex. In this case, by forming a latex, it becomes possible to form a receptive layer by coating a water-dispersed coating liquid to form a receiving layer, thereby reducing the manufacturing cost. As a method for forming a latex, for example, a method described in Japanese Patent No. 3450339 can be used. Examples of the latex-made ultraviolet absorber include ULS-700, ULS-1700, ULS-1383MA, ULS-1635MH, XL-7016, ULS-933LP, ULS-935LH, Shin-Nakamura Chemical Co., Ltd. Commercially available ultraviolet absorbers such as New Coat UVA-1025W, New Coat UVA-204W, and New Coat UVA-4512M (both are trade names) can also be used.
When latex containing a unit having a UV-absorbing ability is made into a latex, the above-mentioned dyeable receiving polymer is also made into a latex in the same manner. Can be formed.

  The addition amount of the polymer containing the unit having ultraviolet absorbing ability or the latex thereof is preferably 5 to 50 parts by mass, more preferably 10 to 30 parts by mass with respect to the dyeable receiving polymer or the latex forming the receptor layer.

The ultraviolet absorber may be an organic compound or an inorganic compound.
In the case of an organic ultraviolet absorber, those represented by the following general formulas (1) to (8) are preferable.

In the formula, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , and R ¹⁵ each independently represent a hydrogen atom, a halogen atom, an alkyl group (including a cycloalkyl group or a bicycloalkyl group), an alkenyl group (a cycloalkenyl group, (Including bicycloalkenyl groups), alkynyl groups, aryl groups, heterocyclic groups, cyano groups, hydroxyl groups, nitro groups, carboxyl groups, alkoxy groups, aryloxy groups, silyloxy groups, heterocyclic oxy groups, acyloxy groups, carbamoyloxy groups , Alkoxycarbonyloxy group, aryloxycarbonyloxy, amino group (including anilino group), acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl or arylsulfonylamino Group, mercap Group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl or arylsulfinyl group, alkyl or arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl or hetero It represents a ring azo group, an imide group, a phosphino group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group, or a silyl group.

In the formula, R ²¹ and R ²² each independently represent a hydrogen atom, a halogen atom, an alkyl group (including a cycloalkyl group or a bicycloalkyl group), an alkenyl group (including a cycloalkenyl group or a bicycloalkenyl group), or an alkynyl group. , Aryl group, heterocyclic group, cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyl Oxy, amino group (including anilino group), acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl or arylsulfonylamino group, mercapto group, alkylthio group , Arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl or arylsulfinyl group, alkyl or arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl or heterocyclic azo group, imide Represents a group, a phosphino group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group, or a silyl group. T represents an aryl group, a heterocyclic ring, or an aryloxy group. Preferably T is an aryl group.

In the formula, X ³¹ , Y ³¹ and Z ³¹ each independently represent a substituted or unsubstituted alkyl group, aryl group, alkoxy group, aryloxy group, alkylthio group, arylthio group, or heterocyclic group. However, at least one of X ³¹ , Y ³¹ and Z ³¹ represents a group represented by the general formula (a).

In the formula, R ³¹ and R ³² each independently represent a hydrogen atom, a halogen atom, an alkyl group (including a cycloalkyl group or a bicycloalkyl group), an alkenyl group (including a cycloalkenyl group or a bicycloalkenyl group), or an alkynyl group. , Aryl group, heterocyclic group, cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyl Oxy, amino group (including anilino group), acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl or arylsulfonylamino group, mercapto group, alkylthio group Arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl or arylsulfinyl group, alkyl and / or arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl or heterocyclic azo group, It represents an imide group, a phosphino group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group, or a silyl group. Further, adjacent R ₃₁ and R ₃₂ may be linked to form a ring.

In the formula, R ^{41 to} R ⁴⁴ each independently represent a hydrogen atom, a halogen atom, an alkyl group (including a cycloalkyl group or a bicycloalkyl group), an alkenyl group (including a cycloalkenyl group or a bicycloalkenyl group), or an alkynyl group. , Aryl group, heterocyclic group, cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyl Oxy, amino group (including anilino group), acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl or arylsulfonylamino group, mercapto group, alkylthio group , Arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl or arylsulfinyl group, alkyl or arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl or heterocyclic azo group, imide Represents a group, a phosphino group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group, or a silyl group.

In the formula, Q represents an aryl group or a 5- or 6-membered heterocycle, R ⁵¹ represents a hydrogen atom or an alkyl group, and X ⁵¹ and Y ⁵¹ each independently represent a cyano group, —COOR ⁵² , —CONR ⁵² R ⁵³ , —COR ⁵² , —SO ₂ OR ⁵² , —SO ₂ NR ⁵² R ⁵³ , each of R ⁵² and R ⁵³ independently represents a hydrogen atom, an alkyl group, or an aryl group. One of R ⁵² and R ⁵³ is preferably a hydrogen atom. X ⁵¹ and Y ⁵¹ may be linked to form a 5- or 6-membered ring. When X ⁵¹ and Y ⁵¹ are a carboxyl group, they may be in a salt form.

In the formula, each of R ⁶¹ and R ⁶² independently represents a hydrogen atom, an alkyl group, an aryl group, or a group of nonmetallic atoms necessary for connecting to each other to form a 5- or 6-membered ring. Further, either R ⁶¹ or R ⁶² may be bonded to the methine group adjacent to the nitrogen atom to form a 5- or 6-membered ring. X ⁶¹ and Y ⁶¹ may be the same or different and have the same ^meanings as X ⁵¹ and Y ⁵¹ in formula (5).

In the formula, each of R ^{71 to} R ⁷⁴ may be the same or different and each represents a hydrogen atom, an alkyl group or an aryl group, and R ⁷¹ and R ⁷⁴ together form a double bond. When R ⁷¹ and R ⁷⁴ are combined to form a double bond, R ⁷² and R ⁷³ may be linked to form a benzene ring or a naphthalene ring. R ⁷⁵ represents an alkyl group or an aryl group, Z ⁷¹ represents an oxygen atom, a sulfur atom, a methylene group, an ethylene group,> N—R ⁷⁶ or> C (R ⁷⁷ ) (R ⁷⁸ ), and R ⁷⁶ represents an alkyl group Represents an aryl group, and R ⁷⁷ and R ⁷⁸ may be the same or different and each represents a hydrogen atom or an alkyl group. X ⁷¹ and Y ⁷¹ may be the same or different and have the same ^meanings as X ⁵¹ and Y ⁵¹ in formula (5). n represents 0 or 1.

In the formula, each of R ^{81 to} R ⁸⁶ independently represents a hydrogen atom, a halogen atom, an alkyl group (including a cycloalkyl group or a bicycloalkyl group), an alkenyl group (including a cycloalkenyl group or a bicycloalkenyl group), an alkynyl group, Aryl group, heterocyclic group, cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy Amino groups (including anilino groups), acylamino groups, aminocarbonylamino groups, alkoxycarbonylamino groups, aryloxycarbonylamino groups, sulfamoylamino groups, alkyl or arylsulfonylamino groups, mercapto groups, alkylthio groups, Arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl or arylsulfinyl group, alkyl or arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl or heterocyclic azo group, imide group Phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, or silyl group, R ₈₇ and R ₈₈ may be the same or different and each represents a hydrogen atom, an alkyl group or an aryl group, R ₈₇ and R ₈₈ may be linked to form a 5- or 6-membered ring.

  In the general formulas (1) to (8) and the general formula (a), each substituent (for example, a group having an alkyl part, an aryl part, or a heterocyclic part) may be substituted with the following substituents. . In addition, examples of the groups in the general formulas (1) to (8) and the general formula (a) and specific groups are exemplified by corresponding groups among the groups shown below.

Such groups are described and exemplified below.
Halogen atom (for example, chlorine atom, bromine atom, iodine atom), alkyl group [represents a linear, branched, or cyclic substituted or unsubstituted alkyl group. They are alkyl groups (preferably alkyl groups having 1 to 30 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, tert-butyl group, n-octyl group, eicosyl group, 2-chloroethyl group, 2-cyanoethyl group, 2-ethylhexyl group), cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, such as cyclohexyl group, cyclopentyl group, 4-n-dodecylcyclohexyl group), Bicycloalkyl group (preferably a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms. For example, bicyclo [ 1,2,2] heptan-2-yl group, bicyclo [2,2,2] octane-3-yl group), It is intended to encompass such tricyclo structure having many cyclic structures into. An alkyl group (for example, an alkyl group of an alkylthio group) in the substituents described below also represents such an alkyl group. ], An alkenyl group [represents a linear, branched or cyclic substituted or unsubstituted alkenyl group. They are an alkenyl group (preferably a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, such as a vinyl group, an allyl group, a prenyl group, a geranyl group, an oleyl group), a cycloalkenyl group (preferably a carbon number of 3 A substituted or unsubstituted cycloalkenyl group having ˜30, that is, a monovalent group obtained by removing one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms, such as a 2-cyclopenten-1-yl group and 2-cyclohexene -1-yl group), a bicycloalkenyl group (substituted or unsubstituted bicycloalkenyl group, preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a hydrogen atom of a bicycloalkene having one double bond. For example, a bicyclo [2,2,1] hept-2-en-1-yl group, It is intended to include cyclo [2,2,2] oct-2-en-4-yl group). ], An alkynyl group (preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms (for example, an ethynyl group, a propargyl group, a trimethylsilylethynyl group), an aryl group (preferably a substituted or unsubstituted group having 6 to 30 carbon atoms) Aryl group such as phenyl group, p-tolyl group, naphthyl group, m-chlorophenyl group, o-hexadecanoylaminophenyl group), heterocyclic group (preferably 5- or 6-membered substituted or unsubstituted, aromatic Alternatively, it is a monovalent group obtained by removing one hydrogen atom from a non-aromatic heterocyclic compound, and more preferably a 5- to 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms. -Furyl group, 2-thienyl group, 2-pyrimidinyl group, 2-benzothiazolyl group), cyano group, hydroxyl group, nitro group, carboxyl Group, alkoxy group (preferably a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms such as methoxy group, ethoxy group, isopropoxy group, tert-butoxy group, n-octyloxy group, 2-methoxyethoxy group) Group), an aryloxy group (preferably a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, such as a phenoxy group, 2-methylphenoxy group, 4-tert-butylphenoxy group, 3-nitrophenoxy group, 2-tetradecanoylaminophenoxy group), a silyloxy group (preferably a silyloxy group having 3 to 20 carbon atoms, such as a trimethylsilyloxy group or a tert-butyldimethylsilyloxy group), a heterocyclic oxy group (preferably a carbon number) 2-30 substituted or unsubstituted heterocyclic oxy groups, 1-phenyl A tolazole-5-oxy group, a 2-tetrahydropyranyloxy group), an acyloxy group (preferably a formyloxy group, a substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, a substituted or unsubstituted group having 6 to 30 carbon atoms. Substituted arylcarbonyloxy groups such as formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxyphenylcarbonyloxy group), carbamoyloxy group (preferably having 1 to 30 carbon atoms) Substituted or unsubstituted carbamoyloxy group, for example, N, N-dimethylcarbamoyloxy group, N, N-diethylcarbamoyloxy group, morpholinocarbonyloxy group, N, N-di-n-octylaminocarbonyloxy group, N- n-octylcarbamoyl An oxy group), an alkoxycarbonyloxy group (preferably a substituted or unsubstituted alkoxycarbonyloxy group having 2 to 30 carbon atoms, such as a methoxycarbonyloxy group, an ethoxycarbonyloxy group, a tert-butoxycarbonyloxy group, and an n-octylcarbonyloxy group. Group), an aryloxycarbonyloxy group (preferably a substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms, for example, phenoxycarbonyloxy group, p-methoxyphenoxycarbonyloxy group, pn-hexadecyl) Oxyphenoxycarbonyloxy group), an amino group (preferably an amino group, a substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted anilino group having 6 to 30 carbon atoms, such as an amino group, Methyla Group, dimethylamino group, anilino group, N-methyl-anilino group, diphenylamino group), acylamino group (preferably formylamino group, substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, carbon number 6-30 substituted or unsubstituted arylcarbonylamino groups such as formylamino group, acetylamino group, pivaloylamino group, lauroylamino group, benzoylamino group, 3,4,5-tri-n-octyloxyphenylcarbonylamino Group), an aminocarbonylamino group (preferably a substituted or unsubstituted aminocarbonylamino group having 1 to 30 carbon atoms, such as a carbamoylamino group, an N, N-dimethylaminocarbonylamino group, an N, N-diethylaminocarbonylamino group). Morpholinocarbonylamino ), An alkoxycarbonylamino group (preferably a substituted or unsubstituted alkoxycarbonylamino group having 2 to 30 carbon atoms, for example, a methoxycarbonylamino group, an ethoxycarbonylamino group, a tert-butoxycarbonylamino group, an n-octadecyloxycarbonylamino group) N-methyl-methoxycarbonylamino group), aryloxycarbonylamino group (preferably a substituted or unsubstituted aryloxycarbonylamino group having 7 to 30 carbon atoms such as phenoxycarbonylamino group, p-chlorophenoxycarbonylamino group) Group, mn-octyloxyphenoxycarbonylamino group), sulfamoylamino group (preferably a substituted or unsubstituted sulfamoylamino group having 0 to 30 carbon atoms, for example, sulfamoylamino Group, N, N-dimethylaminosulfonylamino group, Nn-octylaminosulfonylamino group), alkyl and arylsulfonylamino group (preferably a substituted or unsubstituted alkylsulfonylamino group having 1 to 30 carbon atoms, carbon number 6-30 substituted or unsubstituted arylsulfonylamino groups, for example, methylsulfonylamino group, butylsulfonylamino group, phenylsulfonylamino group, 2,3,5-trichlorophenylsulfonylamino group, p-methylphenylsulfonylamino group ), A mercapto group, an alkylthio group (preferably a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms, such as a methylthio group, an ethylthio group, or an n-hexadecylthio group), an arylthio group (preferably a substituent having 6 to 30 carbon atoms) Or an unsubstituted a Alkylthio, for example, phenylthio group, p-chlorophenylthio group, m-methoxyphenylthio group), heterocyclic thio group (preferably a substituted or unsubstituted heterocyclic thio group having 2 to 30 carbon atoms, for example, 2-benzothia Zolylthio group, 1-phenyltetrazol-5-ylthio group), sulfamoyl group (preferably a substituted or unsubstituted sulfamoyl group having 0 to 30 carbon atoms, such as N-ethylsulfamoyl group, N- (3-dodecyl) Oxypropyl) sulfamoyl group, N, N-dimethylsulfamoyl group, N-acetylsulfamoyl group, N-benzoylsulfamoyl group, N- (N′-phenylcarbamoyl) sulfamoyl group), sulfo group, alkyl or An arylsulfinyl group (preferably a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms) Rusulfinyl group, substituted or unsubstituted arylsulfinyl group of 6 to 30 such as methylsulfinyl group, ethylsulfinyl group, phenylsulfinyl group, p-methylphenylsulfinyl group), alkyl or arylsulfonyl group (preferably having a carbon number) 1-30 substituted or unsubstituted alkylsulfonyl groups, 6-30 substituted or unsubstituted arylsulfonyl groups such as methylsulfonyl group, ethylsulfonyl group, phenylsulfonyl group, p-methylphenylsulfonyl group), acyl groups (Preferably a formyl group, a substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, a substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms, and a substituted or unsubstituted carbon atom having 4 to 30 carbon atoms. Hete bonded to carbonyl group Ring carbonyl groups such as acetyl, pivaloyl, 2-chloroacetyl, stearoyl, benzoyl, pn-octyloxyphenylcarbonyl, 2-pyridylcarbonyl, 2-furylcarbonyl)), aryloxycarbonyl Group (preferably a substituted or unsubstituted aryloxycarbonyl group having 7 to 30 carbon atoms, such as phenoxycarbonyl group, o-chlorophenoxycarbonyl group, m-nitrophenoxycarbonyl group, p-tert-butylphenoxycarbonyl group) An alkoxycarbonyl group (preferably a substituted or unsubstituted alkoxycarbonyl group having 2 to 30 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, a tert-butoxycarbonyl group, or an n-octadecyloxycarbonyl group), Rubamoyl group (preferably a substituted or unsubstituted carbamoyl having 1 to 30 carbon atoms such as carbamoyl group, N-methylcarbamoyl group, N, N-dimethylcarbamoyl group, N, N-di-n-octylcarbamoyl group, N- (methylsulfonyl) carbamoyl group), an aryl or heterocyclic azo group (preferably a substituted or unsubstituted arylazo group having 6 to 30 carbon atoms, a substituted or unsubstituted heterocyclic azo group having 3 to 30 carbon atoms, for example, , Phenylazo group, p-chlorophenylazo group, 5-ethylthio-1,3,4-thiadiazol-2-ylazo group), imide group (preferably N-succinimide group, N-phthalimide group), phosphino group (preferably A substituted or unsubstituted phosphino group having 2 to 30 carbon atoms, such as dimethylphosphino , Diphenylphosphino group, methylphenoxyphosphino group), phosphinyl group (preferably a substituted or unsubstituted phosphinyl group having 2 to 30 carbon atoms, such as phosphinyl group, dioctyloxyphosphinyl group, diethoxyphosphinyl group) Group), a phosphinyloxy group (preferably a substituted or unsubstituted phosphinyloxy group having 2 to 30 carbon atoms, such as a diphenoxyphosphinyloxy group, a dioctyloxyphosphinyloxy group), phosphine A ruamino group (preferably a substituted or unsubstituted phosphinylamino group having 2 to 30 carbon atoms, such as a dimethoxyphosphinylamino group or a dimethylaminophosphinylamino group), a silyl group (preferably a carbon number) 3 to 30 substituted or unsubstituted silyl groups such as trimethylsilyl group, t rt- butyldimethylsilyl group, a phenyl dimethylsilyl group).

  Among the above functional groups, those having a hydrogen atom may be substituted with the above groups by removing this. Examples of such functional groups include an alkylcarbonylaminosulfonyl group, an arylcarbonylaminosulfonyl group, an alkylsulfonylaminocarbonyl group, and an arylsulfonylaminocarbonyl group. Examples thereof include a methylsulfonylaminocarbonyl group, a p-methylphenylsulfonylaminocarbonyl group, an acetylaminosulfonyl group, and a benzoylaminosulfonyl group.

  When the ultraviolet absorber represented by the general formulas (1) to (8) is water-soluble, it preferably has an ionic hydrophilic group. Examples of the ionic hydrophilic group include a sulfo group, a carboxyl group, a phosphono group, and a quaternary ammonium group. As the ionic hydrophilic group, a carboxyl group, a phosphono group, and a sulfo group are preferable, and a carboxyl group and a sulfo group are particularly preferable. The carboxyl group, phosphono group, and sulfo group may be in the form of a salt. Examples of counter ions that form a salt include ammonium ions, alkali metal ions (eg, lithium ions, sodium ions, potassium ions), and organic cations. (Eg, tetramethylammonium ion, tetramethylguanidinium ion, tetramethylphosphonium).

Among the ultraviolet absorbers represented by the above general formulas (1) to (8), those represented by the general formulas (1) to (4) are preferable from the viewpoint that the light fastness of the ultraviolet absorber itself is high, Further, from the absorption characteristics, those represented by (1) to (3) are preferable, and among them, general formulas (1) and (3) are particularly preferable. On the other hand, when used under basic conditions, the compounds represented by the general formulas (4) to (8) are preferred from the viewpoint that coloring due to dissociation does not occur.
Although the specific example of the ultraviolet absorber represented by General formula (1)-(8) below is illustrated, the ultraviolet absorber which can be used by this invention is not limited to these. Here, Ph is a phenyl group, and Me is CH ₃ .

The compounds represented by the general formulas (1) to (8) are disclosed in JP-B-48-30492, JP-A-55-36984, JP-A-55-125875, JP-A-36-10466, JP-A-48-596, 46-3335, 58-214152, 58-221844, 47-10537, 59-19945, 63-53544, 51-56620, 53-128333, 58- No. 181040, JP-A-6-21813, JP-A-7-258228, JP-A-8-239368, JP-A-8-53427, JP-A-10-115898, JP-A-10-147777, JP-A-10-182621, JP-T-8 -501291, etc., U.S. Pat. Nos. 3,754,919, 4,220,711, 2,719,086, 3,698,707, 707,375, 5,298,380, 5,500,332, 5,585,228, 5,814,438, British Patent 1,198,337, European Patent No. 323408A, 5200938A, 521823A, 531258A, 530135A, 5200938A, etc., or can be synthesized according to the methods described therein. .
The structure of typical UV absorbers and their physical properties and mechanism of action are described in Andreas Valet, "Light Stabilizers for Paint", published by Vincentz.

(2) Thermal transfer image receiving sheet Next, the thermal transfer image receiving sheet (image receiving sheet) used in the image forming method of the present invention will be described.
(Basic configuration)
The heat-sensitive transfer image-receiving sheet of the present invention has a structure in which a receiving layer containing a polymer latex and a water-soluble polymer is provided on a support (hereinafter referred to as the heat-sensitive transfer image-receiving sheet of the present invention). There may be at least one intermediate layer between the support and the receiving layer. In the present invention, the intermediate layer is preferably a heat-insulating layer (porous layer), but between the receptor layer and the heat-insulating layer, for example, under a white background adjusting layer, a charge adjusting layer, an adhesive layer, a primer layer, or the like. Formations may be formed and these are also intermediate layers.

The receiving layer and the heat insulating layer are preferably formed by simultaneous multilayer coating. When the underlayer is included, the receiving layer, the underlayer and the heat insulating layer can be formed by simultaneous multilayer coating.
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. Each layer on the back side of the support can be applied by a general method such as roll coating, bar coating, gravure coating, or gravure reverse coating.

(Receptive layer)
The receiving layer serves to receive the dye transferred from the ink sheet and maintain the formed image. In the image receiving sheet of the present invention, the receiving layer contains a polymer latex. The receiving layer may be one layer or two or more layers. Moreover, it is preferable that a receiving layer contains the water-soluble polymer mentioned later.

<Polymer latex>
The polymer latex used in the present invention will be described.
In the heat-sensitive transfer image-receiving sheet of the present invention, the polymer latex that can be used in the receiving layer is preferably a polymer in which a hydrophobic polymer containing water-insoluble vinyl chloride as a monomer unit is dispersed as fine particles in a water-soluble dispersion medium. As the dispersion state, the polymer is emulsified in a dispersion medium, emulsion-polymerized, micelle-dispersed, or partly hydrophilic in the polymer molecule and the molecular chain itself is molecularly dispersed. Any of these may be used. For polymer latex, Tadashi Okuda, Hiroshi Inagaki, “Synthetic Resin Emulsion”, published by Kobunshi Publishing (1978); Takaaki Sugimura, Akio 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 in the range of 1 to 50000 nm, more preferably about 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 may be a normal uniform structure polymer latex or a so-called core / shell type latex. At this time, 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 100 ° C., more preferably 0 ° C. to 80 ° C., further preferably 10 ° C. to 70 ° C., and particularly preferably 15 ° C. to 60 ° C.

  As the polymer latex used in the receiving layer, polyvinyl chlorides and copolymers containing vinyl chloride as monomer units, for example, vinyl chloride vinyl acetate copolymers and vinyl chloride acrylic copolymer polymers can be preferably used. In this case, the ratio of the vinyl chloride monomer is preferably 50% to 95%. These polymers may be linear polymers, branched polymers, crosslinked polymers, so-called homopolymers obtained by polymerizing a single monomer, or two or more types of monomers. It may be a polymerized copolymer. In the case of a copolymer, it may be a random copolymer or a block copolymer. The number average molecular weight of these polymers is usually 5,000 to 100,000, preferably 10,000 to 500,000. When the molecular weight is too small, the layer containing the latex may have insufficient mechanical strength, and when it is too large, the film formability may be poor. A crosslinkable polymer latex is also preferably used.

  Polymer latex that can be used in the present invention is commercially available, for example, G351, G576 manufactured by Nippon Zeon Co., Ltd., Vinibrand 240, 270, 277, 375, 386, 609, 550, 601 manufactured by Nissin Chemical Industry Co., Ltd. 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).

These polymer latexes may be used alone or in combination of two or more as required.
In the receiving layer, the ratio of the copolymer latex containing vinyl chloride as a monomer unit to the total solid content in the layer is preferably 50% or more.
In the present invention, it is essential that the receiving layer contains a polymer latex of at least two kinds of vinyl chloride acrylic copolymers having different chemical structures of monomers in the acrylic part .

  In the present invention, it is preferable to prepare the receptor layer by applying an aqueous coating solution and then drying it. However, “aqueous” as used herein means that 60% by mass or more of the solvent (dispersion medium) of the coating solution is water. Components other than water in the coating solution include methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide, ethyl acetate, diacetone alcohol, furfuryl alcohol, benzyl alcohol, diethylene glycol monoethyl ether, oxyethyl A water-miscible organic solvent such as phenyl ether can be used.

The minimum film-forming temperature (MFT) of the polymer latex is usually −30 ° C. to 90 ° C., preferably about 0 ° C. to 70 ° C. In order to control the minimum film forming temperature, a film forming aid may be added. A film-forming aid, also called a temporary plasticizer, is an organic compound (usually an organic solvent) that lowers the minimum film-forming temperature of polymer latex. For example, Soichi Muroi, “Synthetic Latex Chemistry”, published by Kobunshi Shuppankai (1970) )It is described in. Preferred examples of the film-forming aid include the following compounds, but the film-forming aid that can be used in the present invention is not limited to the following specific examples.
Z-1: benzyl alcohol Z-2: 2,2,4-trimethylpentanediol-1,3-monoisobutyrate Z-3: 2-dimethylaminoethanol Z-4: diethylene glycol

  In the present invention, the above polymer latex may be used (blended) with other polymer latex. Preferable examples of such polymer latex include polylactic acid esters, polyurethanes, polycarbonates, polyesters, polyacetals, and SBRs. Among these, polyesters and polycarbonates can be mentioned.

  Furthermore, the polymer latex used in the present invention may be used in combination with any polymer together with the polymer latex. The polymer that can be used in combination is preferably transparent or translucent and colorless. Natural resins, polymers and copolymers, synthetic resins, polymers and copolymers, and other media for forming films such as gelatins and polyvinyl alcohol , Hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, polyvinylpyrrolidone, casein, starch, polyacrylic acid, polymethylmethacrylic acid, polyvinylchloride, polymethacrylic acid, styrene-maleic anhydride copolymer 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. The binder may be coated from water or an organic solvent or emulsion.

  The binder used in the present invention preferably has a glass transition temperature (Tg) in the range of −30 ° C. to 70 ° C., more preferably in the range of −10 ° C. to 50 ° C. in view of processing brittleness and image storage stability. Preferably it is the range of 0 degreeC-40 degreeC. It is also possible to use a blend of two or more polymers as the binder, and in this case, it is preferable that the weighted average Tg in consideration of the composition falls within the above range. Moreover, when phase-separating or having a core-shell structure, the weighted average Tg is preferably within the above range.

This glass transition temperature (Tg) can be calculated by the following formula.
1 / Tg = Σ (Xi / Tgi)
Here, it is assumed that n monomer components from i = 1 to n are copolymerized in the polymer. Xi is the mass fraction of the i-th monomer (ΣXi = 1), and Tgi is the glass transition temperature (absolute temperature) of the homopolymer of the i-th monomer. However, Σ is the sum from i = 1 to n. In addition, the value of the homopolymer glass transition temperature (Tgi) of each monomer can adopt the value of “Polymer Handbook (3rd Edition)” (J. Brandrup, EHImmergut (Wiley-Interscience, 1989)).

  In the present invention, the polymer used for the binder can be easily obtained by a solution polymerization method, suspension polymerization method, emulsion polymerization method, dispersion polymerization method, anion polymerization method, cationic polymerization, etc. Legal is most preferred. Also preferred is a method of preparing a polymer in a solution and neutralizing or adding an emulsifier and then adding water and forcibly stirring to prepare an aqueous dispersion. The emulsion polymerization method uses, for example, water or a mixed solvent of water and an organic solvent (for example, methanol, ethanol, acetone, etc.) miscible with water as a dispersion medium, and usually 5 to 150% by mass with respect to the dispersion medium. An emulsifier and a polymerization initiator are used with respect to the monomer mixture and the total amount of the monomer, and the polymerization is usually carried out with stirring at about 30 to 100 ° C., preferably 60 to 90 ° C. for 3 to 24 hours. Various conditions such as the dispersion medium, the monomer concentration, the initiator amount, the emulsifier amount, the dispersant amount, the reaction temperature, and the monomer addition method are appropriately set in consideration of the type of monomer used. Moreover, it is preferable to use a dispersing agent as needed.

  Emulsion polymerization is generally performed by Taira Okuda, Hiroshi Inagaki, “Synthetic Resin Emulsion”, published by Kobunshi Publishing (1978); Takaaki Sugimura, Akio Kataoka, Junichi Suzuki, Keiji Kasahara, “Synthetic latex Application ”, published by Polymer Press (1993); Soichi Muroi,“ Synthetic Latex Chemistry ”, published by Polymer Press (1970). As the emulsion polymerization method for synthesizing the polymer latex used in the present invention, a batch polymerization method, a monomer (continuous / divided) addition method, an emulsion addition method, a seed polymerization method, etc. can be selected. From the viewpoint of latex productivity The batch polymerization method, the monomer (continuous / divided) addition method, and the emulsion addition method are preferred.

  The polymerization initiator only needs to have radical generating ability, such as inorganic peroxides such as persulfate and hydrogen peroxide, peroxides described in Nippon Oil & Fats Co., Ltd. organic peroxide catalog, and Wako Pure Chemical Industries, Ltd. The azo compounds described in the catalog of azo polymerization initiators, etc. can be used. Among these, water-soluble peroxides such as persulfate and water-soluble azo compounds described in the Wako Pure Chemical Industries, Ltd. Azo Polymerization Initiator Catalog are preferable. Ammonium persulfate, sodium persulfate, potassium persulfate, azobis ( 2-methylpropionamidine) hydrochloride, azobis (2-methyl-N- (2-hydroxyethyl) propionamide), azobiscyanovaleric acid is more preferable, and in particular, peroxidation such as ammonium persulfate, sodium persulfate, potassium persulfate and the like. The product is preferable from the viewpoint of image preservability, solubility, and cost.

  As the addition amount of the polymerization initiator, the polymerization initiator is preferably 0.3% by mass to 2.0% by mass, and 0.4% by mass to 1.75% by mass with respect to the total amount of monomers. Is more preferable, and 0.5% by mass to 1.5% by mass is particularly preferable.

  As the polymerization emulsifier, any of an anionic surfactant, a nonionic surfactant, a cationic surfactant, and an amphoteric surfactant can be used, but the anionic surfactant has dispersibility and image storability. From the viewpoint, it is preferable to use a sulfonic acid type anionic surfactant because polymerization stability can be secured in a small amount and resistance to hydrolysis, and a long chain represented by Perex SS-H (trade name, Kao Corp.). Alkyl diphenyl ether disulfonate is more preferable, and a low electrolyte type such as Pionine A-43-S (trade name, Takemoto Yushi Co., Ltd.) is particularly preferable.

  As the polymerization emulsifier, a sulfonic acid type anionic surfactant is preferably used in an amount of 0.1% by mass to 10.0% by mass with respect to the total amount of monomers, and 0.2% by mass to 7.5% by mass is used. It is more preferable that 0.3% by mass to 5.0% by mass is used.

  In the synthesis of the polymer latex used in the present invention, it is preferable to use a chelating agent. A chelating agent is a compound capable of coordinating (chelating) multivalent ions such as metal ions such as iron ions and alkaline earth metal ions such as calcium ions. Japanese Patent Publication No. 6-8956, US Pat. JP-A-73645, JP-A-4-127145, JP-A-4-247703, JP-A-4-305572, JP-A-6-11805, JP-A-5-173712, JP-A-5-66527, JP-A-5-66527. 158195, JP-A-6-118580, JP-A-6-110168, JP-A-6-161054, JP-A-6-175299, JP-A-6-214352, JP-A-7-114161, JP-A-7-114154 JP-A-7-120894, JP-A-7-199433, JP-A-7-306504, JP-A-9-43792 May JP 8-314090, JP-A-10-182571, JP-A-10-182570, can be used the compounds described in each publication or the specification of JP-A-11-190892.

  Examples of the chelating agent include inorganic chelate compounds (sodium tripolyphosphate, sodium hexametaphosphate, sodium tetrapolyphosphate, etc.), aminopolycarboxylic acid chelate compounds (nitrilotritriacetic acid, ethylenediaminetetraacetic acid, etc.), organic phosphonic acid chelate compounds ( Research Disclosure 18170, JP-A-52-102726, 53-42730, 56-97347, 54-121127, 55-4024, 55-4025, 55-29883, 55 -126241, 55-65955, 55-65956, 57-179743, 54-61125, and German Patent No. 1045373, and the like, and polyphenolic chelating agents , Polyamine-based clay Preferably such compounds, with aminopolycarboxylic acid derivatives being particularly preferred.

  Preferable examples of the aminopolycarboxylic acid derivatives include the compounds listed in the appendix of “EDTA (-Complexane Chemistry)” (Nanedo, 1977), and some of the carboxyl groups of these compounds are sodium or potassium. Alkali metal salts and ammonium salts such as may be substituted. Particularly preferred aminocarboxylic acid derivatives include iminodiacetic acid, N-methyliminodiacetic acid, N- (2-aminoethyl) iminodiacetic acid, N- (carbamoylmethyl) iminodiacetic acid, nitrilotriacetic acid, ethylenediamine-N, N '-Diacetic acid, ethylenediamine-N, N'-di-α-propionic acid, ethylenediamine-N, N'-di-β-propionic acid, N, N'-ethylene-bis (α-o-hydroxyphenyl) glycine N, N′-di (2-hydroxybenzyl) ethylenediamine-N, N′-diacetic acid, ethylenediamine-N, N′-diacetic acid-N, N′-diacethydroxamic acid, N-hydroxyethylethylenediamine-N , N ′, N′-triacetic acid, ethylenediamine-N, N, N ′, N′-tetraacetic acid, 1,2-propylenediamine-N, N, N ′, N′-tetraacetic acid, d l-2,3-diaminobutane-N, N, N ′, N′-tetraacetic acid, meso-2,3-diaminobutane-N, N, N ′, N′-tetraacetic acid, 1-phenylethylenediamine-N , N, N ′, N′-tetraacetic acid, d, l-1,2-diphenylethylenediamine-N, N, N ′, N′-tetraacetic acid, 1,4-diaminobutane-N, N, N ′, N'-tetraacetic acid, trans-cyclobutane-1,2-diamine-N, N, N ', N'-tetraacetic acid, trans-cyclopentane-1,2-diamine-N, N, N', N'- Tetraacetic acid, trans-cyclohexane-1,2-diamine-N, N, N ′, N′-tetraacetic acid, cis-cyclohexane-1,2-diamine-N, N, N ′, N′-tetraacetic acid, cyclohexane -1,3-diamine-N, N, N ′, N′-tetraacetic acid, cyclohexane-1,4-diamine-N, N N ′, N′-tetraacetic acid, o-phenylenediamine-N, N, N ′, N′-tetraacetic acid, cis-1,4-diaminobutene-N, N, N ′, N′-tetraacetic acid, trans -1,4-diaminobutene-N, N, N ′, N′-tetraacetic acid, α, α′-diamino-o-xylene-N, N, N ′, N′-tetraacetic acid, 2-hydroxy-1 , 3-propanediamine-N, N, N ′, N′-tetraacetic acid, 2,2′-oxy-bis (ethyliminodiacetic acid), 2,2′-ethylenedioxy-bis (ethyliminodiacetic acid), ethylenediamine -N, N'-diacetic acid-N, N'-di-α-propionic acid, ethylenediamine-N, N'-diacetic acid-N, N'-di-β-propionic acid, ethylenediamine-N, N, N ', N'-tetrapropionic acid, diethylenetriamine-N, N, N ′, N ″, N ″ -pentaacetic acid, triethylenetetra -N, N, N ′, N ″, N ′ ″, N ′ ″-hexaacetic acid, 1,2,3-triaminopropane-N, N, N ′, N ″, N ″ Examples include ', N' ''-hexaacetic acid, and those in which some of the carboxyl groups of these compounds are substituted with alkali metal salts such as sodium and potassium, and ammonium salts.

  The addition amount of the chelating agent is preferably 0.01% by mass to 0.4% by mass, more preferably 0.02% by mass to 0.3% by mass with respect to the total amount of monomers. It is especially preferable that it is 03 mass%-0.15 mass%. When the amount of the chelating agent is less than 0.01% by mass, capture of metal ions mixed in the production process of the polymer latex becomes insufficient, stability against aggregation of the latex is lowered, and applicability may be deteriorated. On the other hand, if it exceeds 0.4%, the viscosity of the latex may increase and the coatability may be lowered.

  A chain transfer agent is preferably used for the synthesis of the polymer latex used in the present invention. As the chain transfer agent, those described in “Polymer Handbook, 3rd edition” (Wiley-Interscience, 1989) are preferable. Sulfur compounds are more preferred because they have high chain transfer ability and can be used in small amounts. Hydrophobic mercaptan-based chain transfer agents such as tert-dodecyl mercaptan and n-dodecyl mercaptan are particularly preferred.

  The amount of the chain transfer agent is preferably 0.2% by mass to 2.0% by mass, more preferably 0.3% by mass to 1.8% by mass, and 0.4% by mass to 1.6% by mass with respect to the total amount of monomers. Mass% is particularly preferred.

  In emulsion polymerization, in addition to the above compounds, electrolytes, stabilizers, thickeners, antifoaming agents, antioxidants, vulcanizing agents, antifreezing agents, gelling agents, vulcanization accelerators, etc. are described in synthetic rubber handbooks, etc. These additives may be used.

  In the polymer latex used in the present invention, an aqueous solvent can be used as a solvent in the coating solution, but a water-miscible organic solvent may be used in combination. Examples of the water-miscible organic solvent include alcohols such as methyl alcohol, ethyl alcohol and propyl alcohol, cellosolves such as methyl cellosolve, ethyl cellosolve and butyl cellosolve, ethyl acetate and dimethylformamide. The amount of these organic solvents added is preferably 50% by mass or less, more preferably 30% by mass or less of the solvent.

The polymer latex used in the present invention preferably has a polymer concentration of 10 to 70% by mass, more preferably 20 to 60% by mass, and particularly preferably 30 to 55% by mass with respect to the latex liquid.
In addition, the polymer latex in the image receiving sheet of the present invention includes a gel or a dried film state formed by drying a part of the solvent after coating.

<Water-soluble polymer>
Receiving layer you contain a water-soluble polymer. Water-soluble polymers that can be used in the present invention include natural polymers (polysaccharides, microorganisms, animals), semi-synthetic polymers (cellulose, starch, alginic acid), and synthetic polymers (vinyl, Others), synthetic polymers such as polyvinyl alcohol described below, and natural or semi-synthetic polymers made from plant-derived cellulose or the like correspond to water-soluble polymers that can be used in the present invention. The water-soluble polymer in the present invention does not include the polymer latex.

Of the water-soluble polymers that can be used in the present invention, natural polymers and semi-synthetic polymers will be described in detail. Plant polysaccharides include gum arabic, κ-carrageenan, ι-carrageenan, λ-carrageenan, guar gum (such as Supercol from Squall), locust bean gum, pectin, tragacanth, corn starch (Purity- from National Starch & Chemical Co.) 21), phosphorylated starch (National Starch & Chemical Co. National 78-1898, etc.) and other microbial polysaccharides such as xanthan gum (Kelco Keltrol T), dextrin (National Starch & Chemical Co. Nadex360, etc.) Examples of animal natural polymers include gelatin (such as Crodyne B419 from Croda), casein, sodium chondroitin sulfate (such as Cromoist CS from Croda), and the like (all are trade names). Cellulose systems include ethyl cellulose (ICI Cellofas WLD, etc.), carboxymethyl cellulose (Daicel CMC, etc.), hydroxyethyl cellulose (Daicel HEC, etc.), hydroxypropyl cellulose (Aqualon Klucel, etc.), methyl cellulose (Henkel Viscontran, etc.), Examples include nitrocellulose (such as Isopropyl Wet from Hercules) and cationized cellulose (such as Crodacel QM from Croda). Other starches such as phosphorylated starch (National Starch &Chemical's National 78-1898) and alginic acid are sodium alginate (such as Kelco's Keltone) and propylene glycol alginate. Hi-care1000, etc.) and sodium hyaluronate (Hyalure, etc. from Lifecare Biomedial) are included (all are trade names).
In the present invention, gelatin is one of the preferred embodiments. The gelatin used in the present invention may have a molecular weight of 10,000 to 1,000,000. The gelatin of the present invention may contain anions such as Cl ⁻ , SO ₄ ²⁻ , and cations such as Fe ²⁺ , Ca ²⁺ , Mg ²⁺ , Sn ²⁺ and Zn ^2+. May be.
It is preferable to add gelatin dissolved in water.

  Of the water-soluble polymers that can be used in the present invention, synthetic polymers will be described in detail. Examples of the acrylic system include sodium polyacrylate, polyacrylic acid copolymer, polyacrylamide, polyacrylamide copolymer, polydiethylaminoethyl (meth) acrylate quaternary salt or a copolymer thereof, and the vinyl system includes polyvinylpyrrolidone, Polyvinyl pyrrolidone copolymer, polyvinyl alcohol, etc., including polyethylene glycol, polypropylene glycol, polyisopropylacrylamide, polymethyl vinyl ether, polyethyleneimine, polystyrene sulfonic acid or copolymer thereof, naphthalene sulfonic acid condensate salt, polyvinyl sulfonic acid Or a copolymer thereof, polyacrylic acid or a copolymer thereof, acrylic acid or a copolymer thereof, a maleic acid copolymer, a maleic acid monoester copolymer, an acrylic acid Ylmethylpropane sulfonic acid or its copolymer, etc.), polydimethyl diallylammonium chloride or its copolymer, polyamidine or its copolymer, polyimidazoline, dicyanciamide condensate, epichlorohydrin / dimethylamine condensate, Polyacrylamide Hoffman degradation product, water-soluble polyester (Plus Coat Z-221, Z-446, Z-561, Z-450, Z-565, Z-850, Z-3308, RZ-105, manufactured by Kyodo Chemical Co., Ltd.) , RZ-570, Z-730, RZ-142 (all are trade names)).

Further, it has a superabsorbent polymer described in US Pat. No. 4,960,681, JP-A-62-245260, etc., that is, —COOM or —SO ₃ M (M is a hydrogen atom or an alkali metal). A homopolymer of vinyl monomers or a copolymer of these vinyl monomers or other vinyl monomers (for example, sodium methacrylate, ammonium methacrylate, Sumikagel L-5H (trade name) manufactured by Sumitomo Chemical Co., Ltd.) should also be used. Can do.

Of the water-soluble synthetic polymers that can be used in the present invention, polyvinyl alcohols are preferred.
Hereinafter, polyvinyl alcohol will be described in more detail.
As a complete saponified product, PVA-105 [polyvinyl alcohol (PVA) content 94.0% by mass or more, saponification degree 98.5 ± 0.5 mol%, sodium acetate content 1.5% by mass or less, volatile content 5 0.0 mass% or less, viscosity (4 mass%, 20 ° C.) 5.6 ± 0.4 CPS], PVA-110 [PVA content 94.0 mass%, saponification degree 98.5 ± 0.5 mol%, acetic acid Sodium content 1.5% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20 ° C.) 11.0 ± 0.8 CPS], PVA-117 [PVA content 94.0% by mass, saponification degree 98.5 ± 0.5 mol%, sodium acetate content 1.0 mass%, volatile matter 5.0 mass%, viscosity (4 mass%, 20 ° C.) 28.0 ± 3.0 CPS], PVA-117H [ PVA content 93.5% by mass, saponification degree 99.6 ± 0.3 mol Sodium acetate content 1.85% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20 ° C.) 29.0 ± 3.0CPS], PVA-120 [PVA content 94.0% by mass, Degree of saponification 98.5 ± 0.5 mol%, sodium acetate content 1.0 mass%, volatile content 5.0 mass%, viscosity (4 mass%, 20 ° C.) 39.5 ± 4.5 CPS], PVA- 124 [PVA content 94.0% by mass, saponification degree 98.5 ± 0.5 mol%, sodium acetate content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20 ° C.) 60.0 ± 6.0 CPS], PVA-124H [PVA content 93.5 mass%, saponification degree 99.6 ± 0.3 mol%, sodium acetate content 1.85 mass%, volatile content 5.0 mass %, Viscosity (4% by mass, 20 ° C.) 61.0 ± 6.0 CPS], PVA-CS [PV Content 94.0% by mass, degree of saponification 97.5 ± 0.5 mol%, sodium acetate content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20 ° C.) 27.5 ± 3.0 CPS], PVA-CST [PVA content 94.0% by mass, saponification degree 96.0 ± 0.5 mol%, sodium acetate content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4 mass%, 20 ° C.) 27.0 ± 3.0 CPS], PVA-HC [PVA content 90.0 mass%, saponification degree 99.85 mol% or more, sodium acetate content 2.5 mass%, volatilization 8.5% by mass, viscosity (4% by mass, 20 ° C.) 25.0 ± 3.5 CPS] (all are trade names manufactured by Kuraray Co., Ltd.), and the like.

  As a partially saponified product, PVA-203 [PVA content 94.0% by mass, saponification degree 88.0 ± 1.5 mol%, sodium acetate content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4 mass%, 20 ° C.) 3.4 ± 0.2 CPS], PVA-204 [PVA content 94.0 mass%, saponification degree 88.0 ± 1.5 mol%, sodium acetate content 1.0 mass %, Volatile matter 5.0 mass%, viscosity (4 mass%, 20 ° C.) 3.9 ± 0.3 CPS], PVA-205 [PVA content 94.0 mass%, saponification degree 88.0 ± 1.5 Mol%, sodium acetate content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20 ° C.) 5.0 ± 0.4 CPS], PVA-210 [PVA content 94.0% by mass %, Saponification degree 88.0 ± 1.0 mol%, sodium acetate content 1.0% by mass, volatilization 5.0 mass%, viscosity (4 mass%, 20 ° C.) 9.0 ± 1.0 CPS], PVA-217 [PVA content 94.0 mass%, saponification degree 88.0 ± 1.0 mol%, acetic acid Sodium content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20 ° C.) 22.5 ± 2.0 CPS], PVA-220 [PVA content 94.0% by mass, saponification degree 88.0 ± 1.0 mol%, sodium acetate content 1.0 mass%, volatile matter 5.0 mass%, viscosity (4 mass%, 20 ° C.) 30.0 ± 3.0 CPS], PVA-224 [ PVA content 94.0% by mass, saponification degree 88.0 ± 1.5 mol%, sodium acetate content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20 ° C.) 44. 0 ± 4.0 CPS], PVA-228 [PVA content 94.0% by mass, saponification degree 88.0 ± 1.5 %, Sodium acetate content 1.0 mass%, volatile matter 5.0 mass%, viscosity (4 mass%, 20 ° C.) 65.0 ± 5.0 CPS], PVA-235 [PVA content 94.0 mass %, Saponification degree 88.0 ± 1.5 mol%, sodium acetate content 1.0 mass%, volatile matter 5.0 mass%, viscosity (4 mass%, 20 ° C.) 95.0 ± 15.0 CPS], PVA-217EE [PVA content 94.0% by mass, saponification degree 88.0 ± 1.0 mol%, sodium acetate content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20% ° C) 23.0 ± 3.0 CPS], PVA-217E [PVA content 94.0 mass%, saponification degree 88.0 ± 1.0 mol%, sodium acetate content 1.0 mass%, volatile content 5. 0% by mass, viscosity (4% by mass, 20 ° C.) 23.0 ± 3.0 CPS], PVA-22 E [PVA content 94.0% by mass, saponification degree 88.0 ± 1.0 mol%, sodium acetate content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20 ° C.) 31.0 ± 4.0 CPS], PVA-224E [PVA content 94.0 mass%, saponification degree 88.0 ± 1.0 mol%, sodium acetate content 1.0 mass%, volatile content 5.0 mass %, Viscosity (4 mass%, 20 ° C.) 45.0 ± 5.0 CPS], PVA-403 [PVA content 94.0 mass%, saponification degree 80.0 ± 1.5 mol%, sodium acetate content 1 0.0 mass%, volatile matter 5.0 mass%, viscosity (4 mass%, 20 ° C.) 3.1 ± 0.3 CPS], PVA-405 [PVA content 94.0 mass%, saponification degree 81.5 ± 1.5 mol%, sodium acetate content 1.0 mass%, volatile content 5.0 mass%, viscosity (4 mass %, 20 ° C.) 4.8 ± 0.4 CPS], PVA-420 [PVA content 94.0% by mass, saponification degree 79.5 ± 1.5 mol%, sodium acetate content 1.0% by mass, volatilization Min 5.0 mass%], PVA-613 [PVA content 94.0 mass%, saponification degree 93.5 ± 1.0 mol%, sodium acetate content 1.0 mass%, volatile content 5.0 mass% , Viscosity (4 mass%, 20 ° C.) 16.5 ± 2.0 CPS], L-8 [PVA content 96.0 mass%, saponification degree 71.0 ± 1.5 mol%, sodium acetate content 1. 0 mass% (ash content), volatile content 3.0 mass%, viscosity (4 mass%, 20 ° C.) 5.4 ± 0.4 CPS] (all are trade names manufactured by Kuraray Co., Ltd.), etc. .

  In addition, said measured value was calculated | required according to JISK-6726-1977.

  As for the modified polyvinyl alcohol, those described in Koichi Nagano et al., “Poval” (published by Kobunshi Shuppankai) are used. There is modification by cation, anion, -SH compound, alkylthio compound, silanol.

  As such modified polyvinyl alcohol (modified PVA), C-118, C-318, C-318-2A, C-506 (all are trade names manufactured by Kuraray Co., Ltd.), HL polymer as C polymer. HL-12E, HL-1203 (all are trade names manufactured by Kuraray Co., Ltd.), HM polymer is HM-03, HM-N-03 (all are trade names manufactured by Kuraray Co., Ltd.), KL-118, KL-318, KL-506, KM-118T, KM-618 (all are trade names manufactured by Kuraray Co., Ltd.) as the K polymer, and M-115 (manufactured by Kuraray Co., Ltd.) as the M polymer. (Trade name), MP-102, MP-202, MP-203 (all are trade names manufactured by Kuraray Co., Ltd.) as MP polymers, MPK-1, MPK-2, MPK-3, PK-4, MPK-5, MPK-6 (all are trade names manufactured by Kuraray Co., Ltd.), R polymer as R-1130, R-2105, R-2130 (all are manufactured by Kuraray Co., Ltd.) And V-2250 (trade name, manufactured by Kuraray Co., Ltd.).

  Polyvinyl alcohol can be adjusted in viscosity or stabilized by a small amount of solvent or inorganic salt added to the aqueous solution. For details, refer to the above document, Koichi Nagano et al., “Poval”, Polymer Publications published by the publisher, pages 144 to 154 can be used. As a typical example, it is possible to improve the coating surface quality by containing boric acid, which is preferable. The amount of boric acid added is preferably 0.01 to 40% by mass relative to polyvinyl alcohol.

  Suitable binders are transparent or translucent and are generally colorless and are natural resins, polymers and copolymers, synthetic resins, polymers and copolymers, and other film-forming media such as rubbers, polyvinyl alcohols, hydroxyethylcelluloses, cellulose Acetates, cellulose acetate butyrate, polyvinylpyrrolidone, starch, polyacrylic acid, polymethylmethacrylic acid, polyvinyl chloride, polymethacrylic acid, styrene-maleic anhydride copolymers, styrene-acrylonitrile copolymers Styrene-butadiene copolymers, polyvinyl acetals (eg, polyvinyl formal and polyvinyl butyral), polyesters, polyurethanes, phenoxy resins, polyvinylidene chlorides, polyesters Kishido, polycarbonates, polyvinyl acetates, polyolefins, cellulose esters, a polyamides include the water-soluble.

In the present invention, the water-soluble polymer is preferably polyvinyl alcohol or gelatin, and most preferably gelatin.
The addition amount of the water-soluble polymer in the receiving layer is preferably 1 to 25% by mass, and more preferably 1 to 10% by mass with respect to the entire receiving layer.

<Crosslinking agent>
It is preferable that a part or all of the water-soluble polymer contained in the receiving layer is crosslinked with a crosslinking agent.
As the crosslinking agent, a plurality of groups capable of reacting with an amino group, a carboxyl group, a hydroxyl group, or the like may be contained in the molecule. The crosslinking agent is appropriately selected according to the type of the water-soluble polymer. It is not limited. Each method described in THJames, “THE THEORY OF THE PHOTOGRAPHIC PROCESS FOURTH EDITION” (Macmillan Publishing Co., Inc., published in 1977), pages 77-87, and US Pat. No. 4,678,739 The crosslinking agents described in column 41, JP-A-59-116655, JP-A-62-245261, JP-A-61-18942 and the like are suitable for use. Inorganic compound crosslinking agents (for example, chromium alum, boric acid and salts thereof) and organic compound crosslinking agents are preferred. Moreover, you may use the crosslinking agent which consists of mixed aqueous solution containing the chelating agent and zirconium compound which are 1-7 of pH of Unexamined-Japanese-Patent No. 2003-231775.

  Specific examples of the crosslinking agent include epoxy compounds (diglycidyl ethyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-diglycidyl cyclohexane, N, N-diglycidyl-4- Glycidyloxyaniline, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, compounds described in JP-A-6-329877 and JP-A-7-309954, or Dick Fine EM-60 (trade name, Dainippon Ink & Chemicals, Inc.) Aldehyde compounds (formaldehyde, glyoxal, glutaraldehyde, etc.); active halogen compounds (2,4-dichloro-4-hydroxy-1,3,5-s-triazine, US Pat. No. 3, 325,287 Active compound (1,3,5-trisacryloyl-hexahydro-s-triazine, bisvinylsulfonylmethyl ether, N, N′-ethylene-bis (vinylsulfonylacetamide) ethane) Compounds described in JP-B-53-41220, JP-A-53-57257, JP-A-59-162546, JP-A-60-80846, etc.); Mucohalic acid compounds (such as mucochloroic acid); N-carbamoylpyridinium salt compounds ((1-morpholinocarbonyl-3-pyridinio) methanesulfonate, etc.); haloamidinium salt compounds (1- (1-chloro-1-pyridinomethylene) pyrrolidinium, 2-naphthalenesulfonate, etc.); N-methylol compounds ( Dimethylol urea, methylol dimethyl hydantoin, etc.) Carbodiimide compounds (polycarbodiimides derived from isophorone diisocyanate described in JP-A-59-187029 and JP-B-5-27450, carbodiimide compounds derived from tetramethylxylylene diisocyanate described in JP-A-7-330849, Other branched carbodiimide compounds described in JP-A-10-30024, and carbodiimide compounds derived from dicyclohexylmethane diisocyanate described in JP-A-2000-7642, or carbodilite V-02, V-02-L2, V-04, V-06 , E-01, E-02 (both trade names, Nisshinbo Co., Ltd.), etc .; Oxazoline compounds (oxazoline compounds described in JP-A No. 2001-215653, or Epocros K-1010E, K-1020E, K- 030E, K-2010E, K-2020E, K-2030E, WS-500, WS-700 (all are trade names, Nippon Shokubai Co., Ltd.), etc .; Isocyanate compounds (JP-A-7-304841 and JP-A-8) JP-A-277315, JP-A-10-45866, JP-A-9-71720, JP-A-9-328654, JP-A-9-104814, JP-A-2000-194045, JP-A-2000-194237. And the dispersible isocyanate compound described in JP-A-2003-64149, or Duranate WB40-100, WB40-80D, WT20-100, WT30-100 (all trade names, Asahi Kasei Corporation), CR-60N (Trade name, Dainippon Ink and Chemicals) etc.); polymer hardener (Japanese Patent Laid-Open No. 62-234) Compounds described like 57 JP); boric acid and salts thereof; borax; aluminum alum, and the like.

  Preferred compounds as the crosslinking agent include epoxy compounds, aldehyde compounds, active halogen compounds, active vinyl compounds, N-carbamoylpyridinium salt compounds, N-methylol compounds (such as dimethylol urea and methylol dimethyl hydantoin), and carbodiimide compounds. Oxazoline compounds, isocyanate compounds, polymer hardeners (compounds described in JP-A-62-234157), boric acid and salts thereof, borax, aluminum alum and the like. More preferably, an epoxy compound, an active halogen compound, an active vinyl compound, an N-carbamoylpyridinium salt compound, an N-methylol compound (such as dimethylol urea and methylol dimethyl hydantoin), and a polymer hardener (Japanese Patent Laid-open No. Sho) Compounds described in JP-A-62-234157), boric acid and the like. These crosslinking agents may be used alone or in combination of two or more.

  The cross-linking agent used in the present invention may be added in a state of being premixed in a water-soluble polymer solution, may be added at the end of the preparation process of the coating solution, or may be added immediately before coating. .

Although the water-soluble polymer in the receiving layer varies depending on the type of the crosslinking agent, it is preferably 0.1 to 20% by mass crosslinked with respect to the water-soluble polymer, and 1 to 10% by mass crosslinked. Is more preferable.
The amount of the crosslinking agent used in the present invention varies depending on the type of the water-soluble binder and the crosslinking agent, but is generally 0.1 to 50 parts by mass with respect to 100 parts by mass of the water-soluble polymer in the constituent layer. It is preferably 0.5 to 20 parts by mass, and more preferably 1 to 10 parts by mass.

<Ultraviolet absorber>
In the present invention, an ultraviolet absorber may be added to the receiving layer in order to improve light resistance. At this time, it is possible to fix the UV absorber to the receiving layer by increasing the molecular weight, and to prevent diffusion to the ink sheet or the heat-sensitive transfer cover film, sublimation / transpiration due to heating, and the like.
As the ultraviolet absorber, compounds having various ultraviolet absorber skeletons widely known in the field of information recording can be used. Specific examples include 2-hydroxybenzotriazole type ultraviolet absorbers, 2-hydroxybenzotriazine type ultraviolet absorbers, and compounds having a 2-hydroxybenzophenone type ultraviolet absorber skeleton. A compound having a benzotriazole type or triazine skeleton is preferable from the viewpoint of ultraviolet absorption ability (absorption coefficient) / stability, and a compound having a benzotriazole type or benzophenone type skeleton is preferable from the viewpoint of increasing the molecular weight or forming a latex. Specifically, an ultraviolet absorber described in JP 2004-361936 A can be used.

  The ultraviolet absorber preferably has absorption in the ultraviolet region and does not have an absorption edge in the visible region. Specifically, when a thermal transfer image-receiving sheet is formed by adding to the receiving layer, the reflection density at 370 nm is preferably Abs 0.5 or more, and the reflection density at 380 nm is more preferably Abs 0.5 or more. . The reflection density at 400 nm is preferably Abs 0.1 or less. A high reflection density in the range exceeding 400 nm is not preferable because the image is yellowed.

  In the present invention, the ultraviolet absorber has a high molecular weight, preferably a mass average molecular weight of 10,000 or more, and more preferably a mass average molecular weight of 100,000 or more. As a means for increasing the molecular weight, it is preferable to graft an ultraviolet absorber onto the polymer. The polymer that becomes the main chain preferably has a polymer skeleton that is inferior in dyeability to the dye used in combination. Moreover, it is preferable to have sufficient film strength when the film is formed. The graft ratio of the ultraviolet absorber to the polymer main chain is preferably 5 to 20% by mass, and more preferably 8 to 15% by mass.

Moreover, it is more preferable that the polymer grafted with the ultraviolet absorber is made into a latex. The receptor layer can be formed by forming an aqueous dispersion type coating solution into a latex to form a latex, and the manufacturing cost can be reduced. For example, the method described in Japanese Patent No. 3450339 can be used as a method for forming a latex. Examples of the ultraviolet absorber made into latex include, for example, ULS-700, ULS-1700, ULS-1383MA, ULS-1635MH, XL-7016, ULS-933LP, ULS-935LH, Shin-Nakamura Chemical Co., Ltd. Commercially available ultraviolet absorbers such as New Coat UVA-1025W, New Coat UVA-204W, and New Coat UVA-4512M (both are trade names) can also be used.
When the polymer to which the ultraviolet absorber is grafted is made into a latex, it is possible to form a receiving layer in which the ultraviolet absorber is uniformly dispersed by mixing with the latex of the above-mentioned dyeable receiving polymer and applying it.

  The addition amount of the polymer grafted with the ultraviolet absorber or the latex thereof is preferably 5 to 50 parts by mass, more preferably 10 to 30 parts by mass with respect to the dyeable accepting polymer latex forming the receptor layer.

<Emulsified dispersion>
In the present invention, it is preferable to contain an emulsified dispersion (emulsion) in the receiving layer. This is particularly preferable when a polymer latex is used.
Here, “emulsification” is in accordance with a commonly used definition. For example, according to the Dictionary of Chemistry (Kyoritsu Shuppan Co., Ltd.), “emulsification” is defined as “a phenomenon in which another liquid that does not dissolve in one liquid is dispersed as fine particles to produce an emulsion”. The “emulsified dispersion” means “liquid droplets dispersed in another liquid that does not dissolve them”. In the present invention, a preferable “emulsified dispersion” is an “oil droplet dispersion dispersed in water”. The content of an emulsified dispersion in the image-receiving sheet of the present invention is preferably contained 0.03g / m ² ~25.0g / m ² in the image-receiving ^{sheet, 1.0g / m 2 ~20.0g / m} 2 It is preferably included.

In the present invention, it is preferable that a high boiling point solvent is contained in the oil-soluble component of the emulsified dispersion. Preferred high boiling point solvents include phthalates (dibutyl phthalate, dioctyl phthalate, di-2-ethylhexyl phthalate, etc.), phosphoric acid or phosphonic esters (triphenyl phosphate, tricresyl phosphate, triphosphate phosphate). 2-ethylhexyl, etc.), fatty acid esters (di-2-ethylhexyl succinate, tributyl citrate, etc.), benzoates (2-ethylhexyl benzoate, dodecyl benzoate, etc.), amides (N, N-diethyl, etc.) Dodecanamide, N, N-dimethyloleamide, etc.), alcohol or phenols (isostearyl alcohol, 2,4-di-tert-amylphenol, etc.), anilines (N, N-dibutyl-2-butoxy-5-) tert-octylaniline), chlorinated paraffins, hydrocarbons ( Decylbenzene, diisopropylnaphthalene, etc.), carboxylic acids (2- (2,4-di-tert-amylphenoxy) butyric acid, etc. More preferably, the high boiling point solvent is phosphoric acid or phosphonic acid esters (phosphoric acid triphosphate). Phenyl, tricresyl phosphate, tri-2-ethylhexyl phosphate, etc. In addition, as an auxiliary solvent, an organic solvent having a boiling point of 30 ° C. or higher and 160 ° C. or lower (ethyl acetate, butyl acetate, methyl ethyl ketone, cyclohexanone, methyl cellosolve acetate, dimethyl) The high boiling point solvent is preferably contained in the emulsion dispersion in an amount of 3.0 to 25% by mass, more preferably 5.0 to 20% by mass.
Further, the emulsified dispersion preferably contains an image fastening agent and an ultraviolet absorber. These compounds are represented by the general formulas (B), (Ph), (E-1) to (E-3), (TS-I) to (TS-VII), ( A compound represented by any of (TS-VIIIA) and (UA) to (UE) is preferable. Further, it may contain a water-insoluble and organic solvent-soluble homopolymer or copolymer (preferably the compounds described in paragraph Nos. 0208 to 0234 of JP-A No. 2004-361936).

<Release agent>
In addition, a release agent may be added to the receiving layer in order to prevent thermal fusion with the ink sheet during image formation. As the release agent, silicone oil and phosphoric ester plasticizer fluorine compound can be used, and silicone oil is particularly preferably used. As the silicone oil, modified silicone oils such as epoxy modification, alkyl modification, amino modification, carboxyl modification, alcohol modification, fluorine modification, alkylaralkyl polyether modification, epoxy / polyether modification, and polyether modification are preferably used. A reaction product of vinyl-modified silicone oil and hydrogen-modified silicone oil is preferable. The addition amount of the release agent is preferably 0.2 to 30 parts by mass with respect to the receiving polymer.

The coating amount of the receiving layer is preferably 0.5 to 10 g / m ² (in terms of solid content, hereinafter the coating amount in the present invention is a numerical value in terms of solid content unless otherwise specified). The thickness of the receiving layer is preferably 1 to 20 μm.

(Insulation layer)
The heat insulating layer serves to protect the support from heat during heat transfer using a thermal head. Moreover, since it has high cushioning properties, a thermal transfer image-receiving sheet with high printing sensitivity can be obtained even when paper is used as the substrate. The heat insulating layer may be one layer or two or more layers. The heat insulating layer is provided on the support side from the receptor layer.

In the image receiving sheet of the present invention, the heat insulating layer preferably contains a hollow polymer.
The hollow polymer in the present invention is a polymer particle having independent pores inside the particle. For example, 1) Water is contained inside a partition formed by polystyrene, acrylic resin, styrene-acrylic resin, etc., and after coating and drying Non-foamed hollow particles in which the water inside the particles evaporates outside the particles and the inside of the particles becomes hollow. 2) Low boiling point liquids such as butane and pentane, polyvinylidene chloride, polyacrylonitrile, polyacrylic acid, polyacrylic Foamed microballoons that are covered with a resin comprising any of acid esters or a mixture or polymer thereof, and whose interior is hollowed by the expansion of low-boiling liquid inside the particles by heating after coating, 3) above (2) can be heated and foamed in advance to form a hollow polymer.

  These hollow polymers preferably have a hollow ratio of about 20 to 70%, and can be used by mixing two or more kinds as necessary. Specific examples of 1) include Low and Haas Ropaque 1055, Dainippon Ink Boncoat PP-1000, JSR SX866 (B), Nippon Zeon Nipol MH5055 (all trade names), and the like. . Specific examples of 2) include F-30 and F-50 (both trade names) manufactured by Matsumoto Yushi Seiyaku Co., Ltd. Specific examples of 3) include F-30E manufactured by Matsumoto Yushi Seiyaku Co., Ltd., EXPANSEL 461DE, 551DE, and 551DE20 (all trade names) manufactured by Nippon Ferrite Co., Ltd. The hollow polymer used for the heat insulating layer may be made into a latex.

  The heat insulating layer containing the hollow polymer preferably contains a water-dispersed resin or a water-soluble resin as a binder resin as a binder resin. Examples of the binder resin used in the present invention include acrylic resins, styrene-acrylic copolymers, polystyrene resins, polyvinyl alcohol resins, vinyl acetate resins, ethylene-vinyl acetate copolymers, vinyl chloride vinyl acetate copolymers, and styrene. Known resins such as butadiene copolymers, polyvinylidene chloride resins, cellulose derivatives, casein, starch, and gelatin can be used. These resins can be used alone or in combination.

The solid content of the hollow polymer in the heat insulating layer is preferably between 5 and 2000 parts by mass when the solids content of the binder resin is 100 parts by mass. Moreover, 1-70 mass% is preferable, and, as for the mass ratio which occupies with respect to the coating liquid of the solid content of a hollow polymer, 10-40 mass% is more preferable. If the hollow polymer ratio is too small, sufficient heat insulation may not be obtained. May cause problems.
The particle size of the hollow polymer is preferably from 0.1 to 20 μm, more preferably from 0.1 to 2 μm, particularly preferably from 0.1 to 1 μm. Further, the glass transition temperature (Tg) of the hollow polymer is preferably 70 ° C. or higher, and more preferably 100 ° C. or higher.

In the heat-receiving layer, the image-receiving sheet of the present invention does not contain an aqueous dispersion of a resin that is not resistant to organic solvents, in addition to the hollow polymer. It is not preferable to include a resin (dye dyeing resin) that is not resistant to an organic solvent in the heat insulating layer because blurring of an image after image transfer increases. This is because the dye-stainable resin and the hollow polymer exist in the heat insulating layer, so that the dye dyed on the receiving layer after the transfer moves over time through the adjacent heat-insulating layer. it is conceivable that.
Here, “not resistant to organic solvent” means that the solubility in an organic solvent (methyl ethyl ketone, ethyl acetate, benzene, toluene, xylene, etc.) is 1% by mass or less, preferably 0.5% by mass or less. Say. For example, the polymer latex is included in “resin not resistant to organic solvent”.

Moreover, it is preferable that a heat insulation layer contains the said water-soluble polymer. The compounds that can be preferably used are the same as described above.
The amount of the water-soluble polymer added to the heat insulating layer is preferably 1 to 75% by mass and more preferably 1 to 50% by mass with respect to the entire heat insulating layer.

The heat insulating layer preferably contains gelatin. The amount of the heat insulating layer in the gelatin coating solution is preferably 0.5 to 14% by mass, particularly preferably 1 to 6% by mass. The coating amount of the hollow polymer in the heat insulation layer is preferably ^{1~100g / m 2, 5~20g / m} 2 is more preferable.

Moreover, it is preferable that the water-soluble polymer contained in the heat insulation layer is crosslinked by a crosslinking agent. The preferred range of the crosslinking agent that can be preferably used and the amount of use thereof is the same as described above.
Although the water-soluble polymer in the heat insulating layer varies depending on the type of the crosslinking agent, it is preferably 0.1 to 20% by mass crosslinked with respect to the water-soluble polymer, and 1 to 10% by mass crosslinked. Is more preferable.

  The thickness of the heat insulating layer containing the hollow polymer is preferably 5 to 50 μm, and more preferably 5 to 40 μm.

(Underlayer)
An undercoat layer may be formed between the receiving layer and the heat insulating layer. For example, a white background adjusting layer, a charge adjusting layer, an adhesive layer, and a primer layer are formed. About these layers, it can be set as the structure similar to what was described, for example in patent 3585599, patent 2925244, etc.

(Support)
In the present invention, it is preferable to use a water-resistant support as the support. By using a water-resistant support, it is possible to prevent moisture from being absorbed into the support, and to prevent a change in performance of the receiving layer over time. As the water-resistant support, for example, coated paper or laminated paper can be used.

<Coated paper>
The coated paper is a paper obtained by coating various sheets of resin, rubber latex or polymer material on one or both sides of a sheet such as a base paper, and the coating amount varies depending on the application. Examples of such coated paper include art paper, cast coated paper, Yankee paper, and the like.

  As the resin applied to the surface of the base paper or the like, it is appropriate to use a thermoplastic resin. Examples of such a thermoplastic resin include the following thermoplastic resins (a) to (h).

(A) Polyolefin resins such as polyethylene resins and polypropylene resins, copolymer resins of olefins such as ethylene and propylene and other vinyl monomers, acrylic resins, and the like.
(B) A thermoplastic resin having an ester bond. For example, a dicarboxylic acid component (these dicarboxylic acid components may be substituted with a sulfonic acid group, a carboxyl group, etc.) and an alcohol component (these alcohol components may be substituted with a hydroxyl group, etc.) Polyester resin obtained by condensation of poly (methyl methacrylate), polybutyl methacrylate, polymethyl acrylate, polybutyl acrylate, etc. or polymethacrylate resin, polycarbonate resin, polyvinyl acetate resin, styrene acrylate resin, styrene -Methacrylic acid ester copolymer resin, vinyl toluene acrylate resin, etc. are mentioned.
Specific examples include those described in JP-A Nos. 59-101395, 63-7971, 63-7972, 63-7773, and 60-294862. it can.
Commercially available products include Byron 290, Byron 200, Byron 280, Byron 300, Byron 103, Byron GK-140, Byron GK-130 manufactured by Toyobo Co., Ltd., Tufton NE-382, Tufton manufactured by Kao Corporation U-5, ATR-2009, ATR-2010; Elitel UE3500, UE3210, XA-8153, KZA-7049, KZA-1449 manufactured by Unitika Ltd. Polyester TP-220, R manufactured by Nippon Synthetic Chemical Co., Ltd. -188; various types of thermoplastic resins of the Hiros series manufactured by Seiko Chemical Industry Co., Ltd. (all trade names).

(C) Polyurethane resin etc. are mentioned.
(D) Polyamide resin, urea resin, etc. are mentioned.
(E) Polysulfone resin and the like.
(F) Polyvinyl chloride resin, polyvinylidene chloride resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl propionate copolymer resin, and the like.
(G) Cellulose resins such as polyol resins, ethyl cellulose resins, and cellulose acetate resins, such as polyvinyl butyral.
(H) Polycaprolactone resin, styrene-maleic anhydride resin, polyacrylonitrile resin, polyether resin, epoxy resin, phenol resin and the like.
In addition, the said thermoplastic resin may be used individually by 1 type, and may use 2 or more types together.

  Further, the thermoplastic resin may contain pigments or dyes such as brighteners, conductive agents, fillers, titanium oxide, ultramarine blue, and carbon black as required.

<Laminated paper>
The laminated paper is a paper obtained by laminating various resins, rubber or polymer sheets or films on a sheet such as a base paper. Examples of the laminate material include polyolefin, polyvinyl chloride, polyethylene terephthalate, polystyrene, polymethacrylate, polycarbonate, polyimide, triacetyl cellulose, and the like. These resins may be used alone or in combination of two or more.

  In general, the polyolefin is often formed using low density polyethylene, but in order to improve the heat resistance of the support, polypropylene, a blend of polypropylene and polyethylene, high density polyethylene, high density polyethylene and low density polyethylene, It is preferable to use a blend of In particular, it is most preferable to use a blend of high-density polyethylene and low-density polyethylene from the viewpoint of cost, suitability for lamination, and the like.

The blend of the high density polyethylene and the low density polyethylene is used, for example, in a blend ratio (mass ratio) of 1/9 to 9/1. The blend ratio is preferably 2/8 to 8/2, and more preferably 3/7 to 7/3. When forming a thermoplastic resin layer on both surfaces of the support, the back surface of the support is preferably formed using, for example, high-density polyethylene or a blend of high-density polyethylene and low-density polyethylene. The molecular weight of the polyethylene is not particularly limited, but the melt index is 1.0 to 40 g / 10 min for both high-density polyethylene and low-density polyethylene, and has an extrudability. preferable.
In addition, you may perform the process which gives white reflectivity to these sheets or films. Examples of such a treatment method include a method of blending a pigment such as titanium oxide in these sheets or films.

  The thickness of the support is preferably 25 μm to 300 μm, more preferably 50 μm to 260 μm, and further preferably 75 μm to 220 μm. Various stiffnesses can be used according to the purpose, and the support for a photographic image receiving sheet for electrophotography is close to a support for color silver halide photography. Those are preferred.

(Curl adjustment layer)
If the support is exposed as it is, the heat-sensitive transfer image-receiving sheet may be curled due to the humidity and temperature in the environment. Therefore, it is preferable to form a curl adjusting layer on the back side of the support. The curl adjusting layer not only prevents the image receiving sheet from curling but also serves as a waterproof. For the curl adjusting layer, polyethylene laminate, polypropylene laminate, or the like is used. Specifically, it can be formed in the same manner as described in, for example, JP-A-61-110135 and JP-A-6-202295.

(Writing layer / Charge adjustment layer)
An inorganic oxide colloid, an ionic polymer, or the like can be used for the writing layer and the charge adjusting layer. As the antistatic agent, for example, a cationic antistatic agent such as a quaternary ammonium salt or a polyamine derivative, an anionic antistatic agent such as an alkyl phosphate, or a nonionic antistatic agent such as a fatty acid ester can be used. . Specifically, it can be formed in the same manner as that described in, for example, Japanese Patent No. 3585585.

The method for producing the thermal transfer image receiving sheet of the present invention will be described below.
The heat-sensitive transfer image-receiving sheet of the present invention can be produced by applying each layer by a general method such as roll coating, bar coating, gravure coating, and gravure reverse coating, and drying them.
The heat-sensitive transfer image-receiving sheet of the present invention can also be formed by simultaneously applying a receiving layer and a heat insulating layer on a support.
When producing a multi-layer image receiving sheet comprising a plurality of layers having different functions (such as a bubble layer, a heat insulating layer, an intermediate layer, and a receiving layer) on a support, JP-A Nos. 2004-106283 and 2004-181888 are disclosed. In addition, it is known that each layer is sequentially coated as disclosed in each publication such as JP-A 2004-345267, or the layers are previously applied on a support and bonded together. On the other hand, it is known in the photographic industry that productivity is greatly improved, for example, by applying a plurality of layers simultaneously. For example, JP-A Nos. 2,761,791, 2,681,234, 3,508,947, 4,457,256, 3,993,019, Kaisho 63-54975, JP-A-61-278848, 55-86557, 52-31727, 55-142565, 50-43140, 63-80872, 54-54020 JP-A-5-104061, JP-A-5-127305, JP-B-49-7050, or specification, Edgar B. Gutoff et al., "Coating and Drying Defects: Troubleshooting Operating Problems", John Wiley & Sons, 1995. , 101-103, etc., so-called slide coating (slide coating method) and curtain coating (curtain coating method) are known.
In the present invention, the simultaneous multi-layer coating is used for manufacturing a multi-layer image-receiving sheet, whereby productivity can be greatly improved and image defects can be greatly reduced.

In the present invention, the plurality of layers are composed mainly of a resin. The coating solution for forming each layer is preferably water-dispersed latex. The solid content weight of the latex resin in the coating solution of each layer is preferably in the range of 5 to 80%, particularly preferably in the range of 20 to 60%. The average particle size of the resin contained in the water-dispersed latex is 5 μm or less and particularly preferably 1 μm or less. The water-dispersed latex may contain a known additive such as a surfactant, a dispersant, and a binder resin as necessary.
In the present invention, it is preferable to form a laminate of a plurality of layers on a support by the method described in US Pat. No. 2,761,791 and then solidify immediately. As an example, in the case of a multilayer structure solidified by a resin, it is preferable to quickly raise the temperature after forming a plurality of layers on the support. When a binder that gels at a low temperature such as gelatin is included, it may be preferable to quickly lower the temperature after forming a plurality of layers on the support.
The coating amount of a coating solution per one layer constituting the multilayer in the present invention in the range of 1g / m ² ~500g / m ² is preferred. The number of layers in the multilayer configuration can be arbitrarily selected as 2 or more. The receiving layer is preferably provided as the layer furthest away from the support.

(3) Image formation Image formation is performed by superimposing a thermal transfer cover film and an ink sheet and transferring the ink in the ink sheet to the receiving layer of the thermal transfer cover film by applying thermal energy from the ink sheet side. Done.

  When the heat-sensitive transfer image-receiving sheet of the present invention does not have a dye layer containing a diffusion transfer dye, the image is formed using an ink sheet and then transferred using the heat-sensitive transfer image-receiving sheet of the present invention. In other words, the thermal transfer image-receiving sheet and the ink sheet are superposed and thermal energy is applied from the ink sheet side to thermally transfer the ink to form an image, and then the thermal transfer image-receiving sheet on which the image is transferred is subjected to the sensitivity of the present invention. The heat transfer cover film is overlaid and heat energy is applied from the base film side of the heat transfer cover film, whereby the transparent resin layer of the heated portion is transferred and adhered to the heat transfer image-receiving sheet. Finally, the transparent resin layer other than the heated portion is peeled from the heat-sensitive transfer image-receiving sheet together with the base film.

  On the other hand, when the heat-sensitive transfer cover film of the present invention has a dye layer (for example, a sublimation dye layer or a wax ink layer) containing a diffusion transfer dye and also has a function as an ink sheet, image formation and This is preferable because the transparent resin layer can be transferred at a time. That is, the heat-sensitive transfer cover film of the present invention and the heat-sensitive transfer image-receiving sheet are superposed and heated from the base film side of the heat-sensitive transfer cover film by a thermal head, and the transparent resin layer of the heated portion is heated together with the ink. Then, the transparent resin layer other than the heated portion is peeled from the heat-sensitive transfer image-receiving sheet together with the base film.

  Even when the thermal transfer cover film of any aspect is used, in the image forming method of the invention, the thermal adhesive layer of the thermal transfer cover film and the receiving layer of the thermal transfer image-receiving sheet are overlapped so as to face each other. Then, the thermal transfer cover film is heated by the thermal head from the base film side, the transparent resin layer of the heated portion is transferred and adhered to the thermal transfer image-receiving sheet, and the transparent resin layer other than the heated portion is transferred to the sensitive film together with the base film. It includes a step of peeling from the thermal transfer image receiving sheet.

Any conventionally known applying means can be used as the means for applying thermal energy during thermal transfer. For example, by applying a thermal energy of about 5 to 100 mJ / mm ² by controlling the recording time with a recording device such as a thermal printer (for example, product name, video printer VY-100, manufactured by Hitachi, Ltd.) The purpose of can be fully achieved. Furthermore, it can be performed in the same manner as described in, for example, JP-A-2005-88545. In the present invention, the printing time is preferably less than 15 seconds, and more preferably 5 to 12 seconds, from the viewpoint of shortening the time until the printed matter is provided to the consumer.

In addition, the thermal transfer image-receiving sheet used in the present invention can be used in various applications such as a sheet- or roll-shaped thermal transfer image-receiving sheet, cards, and a transmissive original document sheet that can be thermally transferred and recorded by appropriately selecting a support. It can also be applied to.
The present invention can be used in printers, copiers and the like using a thermal transfer recording system.

  The features of the present invention will be described more specifically with reference to synthesis examples and 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. In Examples, “part” or “%” is based on mass unless otherwise specified.

Production Example 1 (Preparation of thermal transfer cover films D1 to D4)
(Preparation of thermal transfer cover film D1)
A 6.0 μm thick polyester film (Lumirror, trade name, manufactured by Toray Industries, Inc.) with heat-resistant slip treatment applied to the back side with a thermosetting acrylic resin (thickness 1 μm) on the back side is used. A transparent resin layer coating liquid having the following composition was applied and dried so as to have a ratio of 1 g / m ^{2 based on} the solid content, thereby forming a transparent resin layer.
<Transparent resin layer coating solution>
60 parts by mass of acrylic silicone graft resin (XSA-100, trade name, manufactured by Toa Gosei Co., Ltd.)
The following ultraviolet absorber 1 20 parts by mass Methyl ethyl ketone 20 parts by mass Toluene 20 parts by mass

On the surface of the formed transparent resin layer, an adhesive layer coating solution having the following composition was applied and dried so as to have a ratio of 0.7 g / m ^{2 based on} the solid content, thereby forming an adhesive layer.
<Adhesive layer coating solution>
30 parts by mass of vinyl chloride / vinyl acetate copolymer (VYLF, trade name, manufactured by UCC, Tg = 68 ° C., polymerization degree 220)
Microsilica 0.4 parts by mass Methyl ethyl ketone 35 parts by mass Toluene 35 parts by mass

Next, a yellow coating solution, a magenta coating solution, and a cyan coating solution having the following composition are repeatedly applied to the surface of the adhesive layer by a gravure coating method in the order of yellow, magenta, and cyan in a width of 15 cm, respectively ( The coating amount at the time of dry film 1 g / m ² ) and dried to form ink layers of three colors to produce a thermal transfer cover film D1.

<Yellow coating solution>
5.5 parts by mass of dye (macrolex yellow 6G, trade name, manufactured by Bayer Co., Ltd.)
Polyvinyl butyral resin 4.5 parts by mass (ESREC BX-1, trade name, manufactured by Sekisui Chemical Co., Ltd.)
Methyl ethyl ketone / toluene (mass ratio 1/1) 90 parts by mass <Magenta coating solution>
Magenta dye (Disperse Red 60) 5.5 parts by mass Polyvinyl butyral resin 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 coating solution>
Cyan dye (Solvent Blue 63) 5.5 parts by mass Polyvinyl butyral resin 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)

(Preparation of thermal transfer cover film D2)
It was produced in the same manner as the thermal transfer cover film D1, except that an equimolar amount of the following ultraviolet absorbent 2 was used instead of the ultraviolet absorbent 1 used in the thermal transfer cover film D1.

(Preparation of thermal transfer cover film D3)
It was produced in the same manner as the thermal transfer cover film D1 except that an equimolar amount of the following ultraviolet absorbent 3 was used instead of the ultraviolet absorbent 1 used in the thermal transfer cover film D1.

(Preparation of thermal transfer cover film D4)
A heat-sensitive transfer cover film D1 was prepared in the same manner as the heat-sensitive transfer cover film D1, except that the ultraviolet absorbent 1 was omitted.

Production Example 2 (Production of thermal transfer image-receiving sheets R101 to R103)
(Preparation of thermal transfer image-receiving sheet R101)
Synthetic paper (YUPO FPG200, thickness 200 μm, trade name, manufactured by YUPO Corporation) is used as a support, and the receiving layer coating solution 101 having the following composition is 4.0 g / m ^{2 on} one surface. After being applied and dried naturally, it was allowed to stand at 40 ° C. and a relative humidity of 70% for 10 hours.

<Receptive layer coating solution 101>
50 parts by weight of vinyl chloride polymer latex (Nishin Chemical Industry Co., Ltd. Vinibrand 900)
10 parts by weight of vinyl chloride polymer latex (Nishin Chemical Industry Co., Ltd. BiniBran 276 modified 1)
Gelatin 2.5 parts by weight Microcrystalline wax (EMUSTAR042X manufactured by Nippon Seiki Co., Ltd.) 5 parts by weight Water 8 parts by weight Amount necessary to adjust NaOH pH to 8

(Preparation of thermal transfer image-receiving sheet R102)
It was prepared in the same manner as the thermal transfer image receiving sheet R101 except that the receiving layer coating liquid 101 used in the thermal transfer image receiving sheet R101 was changed to the following receiving layer coating liquid 102.

<Receptive layer coating solution 102>
50 parts by weight of vinyl chloride polymer latex (Nishin Chemical Industry Co., Ltd. Vinibrand 900)
10 parts by weight of vinyl chloride polymer latex (Nishin Chemical Industry Co., Ltd. BiniBran 276 modified 1)
Polyvinyl alcohol 2.5 parts by weight Microcrystalline wax (EMUSTAR042X, manufactured by Nippon Seiki Co., Ltd.) 5 parts by weight Water 8 parts by weight Amount necessary to make NaOH pH 8

(Preparation of thermal transfer image-receiving sheet R103)
It was produced in the same manner as the thermal transfer image receiving sheet R101 except that the receiving layer coating solution 101 used in the thermal transfer image receiving sheet R101 was changed to the following receiving layer coating solution 103.

<Receptive layer coating solution 103>
60 parts by mass of polyester polymer latex (Toyobo Co., Ltd. Bironal MD1200)
Gelatin 2.5 parts by weight Microcrystalline wax (EMUSTAR042X manufactured by Nippon Seiki Co., Ltd.) 5 parts by weight Water 8 parts by weight Amount necessary to adjust NaOH pH to 8

Example 1 (Image formation and evaluation)
The heat-sensitive transfer cover films D1 to D4 produced in Production Example 1 and the heat-sensitive transfer image-receiving sheets R101 to R103 produced in Production Example 2 are in contact with the heat-sensitive adhesive layer of the heat-sensitive transfer cover film and the receiving layer of the heat-sensitive transfer image-receiving sheet. Using a thermal head from the back side of the thermal transfer cover film, printing was performed under the conditions of thermal head output of 0.25 W / dot, pulse width of 0.15 to 15 ms, and dot density of 6 dots / mm. The dye was dyed on the receiving layer of the thermal transfer image-receiving sheet. Next, the recorded thermal transfer image-receiving sheet obtained as described above was irradiated with Xe light (17000 lux) for 14 days, and a light fastness test was performed. The light fastness is evaluated by measuring the status A reflection density after irradiation of the portion showing the status A reflection density 1.0, and the average remaining ratio (percentage) of yellow, magenta, and cyan with respect to the reflection density 1.0 before irradiation. It was done by seeking. Table 1 below shows the residual ratio of the pigment.

From Table 1 above, an image formed by a thermal transfer method using a thermal transfer image-receiving sheet having a receiving layer containing a polymer latex and a water-soluble polymer and a thermal transfer cover film having a transparent resin layer containing an ultraviolet absorber is as follows: It was confirmed that the light fastness was higher than that of an image formed using a heat-sensitive transfer cover film containing no ultraviolet absorber.

Production Example 3 (Production of thermal transfer image-receiving sheets R201 and R202)
(Preparation of emulsified dispersion A)
11.0 g of high boiling point solvent (the following Solv-5), 9 g of the following KF-96 (manufactured by Shin-Etsu Chemical Co., Ltd.), 15.5 g of the following EB-9, and 7.5 g of the following B-47 And 20 ml of ethyl acetate were mixed, and the resulting solution was emulsified and dispersed in 250 g of a 20% by weight gelatin aqueous solution containing 1 g of sodium dodecylbenzenesulfonate with a high-speed stirring emulsifier (dissolver), and water was added to 380 g of emulsification. Product A was prepared.

(Preparation of thermal transfer image-receiving sheet R201)
It was produced in the same manner as the thermal transfer image receiving sheet R101 except that the receiving layer coating liquid 101 used in the thermal transfer image receiving sheet R101 was changed to the following receiving layer coating liquid 201.
<Receptive layer coating solution 201>
50 parts by weight of vinyl chloride polymer latex (Nissin Chemical Industry Co., Ltd., Vinyblan 900)
10 parts by weight of vinyl chloride polymer latex (manufactured by Nissin Chemical Industry Co., Ltd., VINYBRAN 276)
Emulsified dispersion A 3.5 parts by mass (Emulsion A contains gelatin which is a water-soluble polymer)
Microcrystalline wax 5 parts by mass (Nippon Seiki Co., Ltd., EMUSTAR042X)
8 parts by weight of water The amount necessary to make NaOH pH 8

(Preparation of thermal transfer image-receiving sheet R202)
It was produced in the same manner as the thermal transfer image receiving sheet R101 except that the receiving layer coating liquid 101 used in the thermal transfer image receiving sheet R101 was changed to the following receiving layer coating liquid 202.

<Receptive layer coating liquid 202>
60 parts by mass of polyester polymer latex (manufactured by Toyobo Co., Ltd., Bironal MD1200)
Emulsified dispersion A 3.5 parts by mass (Emulsion A contains gelatin which is a water-soluble polymer)
Microcrystalline wax 5 parts by mass (Nippon Seiki Co., Ltd., EMUSTAR042X)
8 parts by weight of water The amount necessary to make NaOH pH 8

Example 2 (Image formation and evaluation)
Using the heat-sensitive transfer cover films D1 to D4 produced in Production Example 1 and the heat-sensitive transfer image-receiving sheets R201 and R202 produced in Production Example 3, image formation was performed in the same manner as in Example 1 to evaluate light fastness. went. The results are shown in Table 2 below.

From Table 2 above, an image formed by a thermal transfer method using a thermal transfer image-receiving sheet having a receiving layer containing an emulsified dispersion and a thermal transfer cover film having a transparent resin layer containing an ultraviolet absorber is further light-fast. Was confirmed to be high.

Production Example 4 (Production of thermal transfer image-receiving sheets R301 and R302)
The heat- sensitive transfer image-receiving sheet R201 was prepared in the same manner as the heat- sensitive transfer image-receiving sheet R201, except that a heat-insulating layer was newly applied between the support and the receiving layer using the following heat-insulating layer coating liquid 301.

< Insulation layer coating liquid 301>
150 parts by mass of hollow polymer latex (manufactured by Nippon Zeon Co., Ltd., MH5055)
(Aqueous dispersion of hollow structure polymer with outer diameter of 0.5 μm)
90% by weight of 10% aqueous gelatin solution Amount necessary to make NaOH pH 8

(Preparation of thermal transfer image receiving sheet R302)
The heat- sensitive transfer image-receiving sheet R202 was prepared in the same manner as the heat- sensitive transfer image-receiving sheet R202, except that a heat-insulating layer was newly applied between the support and the receiving layer using the above heat-insulating layer coating liquid 301.

Example 3 (Image formation and evaluation)
Using the thermal transfer cover films D1 to D3 produced in Production Example 1, the thermal transfer sheets R301 and R302 produced in Production Example 4, and R201 produced in Production Example 3, an image was formed in the same manner as in Example 1. Then, the light fastness was evaluated. The results are shown in Table 3, and the average maximum transfer densities (Dmax) of yellow, magenta and cyan are also shown.

From Table 3 above, an image formed by a thermal transfer method using a thermal transfer image-receiving sheet containing a hollow polymer in a heat insulating layer and a thermal transfer cover film containing an ultraviolet absorber in a transparent resin layer has only high light fastness. It was also confirmed that the transfer density was high.

Production Example 5 (Production of thermal transfer image-receiving sheets R401 and R402)
(Preparation of emulsified dispersion B)
13.5 g of a high boiling point solvent (Solv-5 above), 19 g of the above EB-9, 9 g of the above B-47, and 20 ml of ethyl acetate were mixed with 1 g of dodecylbenzenesulfonic acid. Emulsion B of 380 was prepared by emulsifying and dispersing in 250 g of a 20% by weight gelatin aqueous solution containing sodium with a high-speed stirring emulsifier (dissolver) and adding water.

(Preparation of thermal transfer image-receiving sheet R401)
The heat- sensitive transfer image-receiving sheet R201 was prepared in the same manner as the heat- sensitive transfer image-receiving sheet R201, except that a heat-insulating layer was newly applied between the support and the receiving layer using the following heat-insulating layer coating solution 401. .

< Insulation layer coating solution 401>
150 parts by mass of hollow polymer latex (manufactured by Nippon Zeon Co., Ltd., MH5055)
(Aqueous dispersion of hollow structure polymer with outer diameter of 0.5 μm)
50% by weight of 10% aqueous gelatin solution 60 parts by weight of the above emulsion B Amount necessary to make NaOH pH 8

(Preparation of thermal transfer image receiving sheet R402)
The heat- sensitive transfer image-receiving sheet R202 was prepared in the same manner as the heat- sensitive transfer image-receiving sheet R202, except that a heat-insulating layer was newly applied between the support and the receiving layer using the heat-insulating layer coating liquid 401.

Example 4 (Image formation and evaluation)
Using the heat-sensitive transfer cover films D1 to D3 produced in Production Example 1 and the heat-sensitive transfer sheets R401 and R402 produced in Production Example 5, an image was formed in the same manner as in Example 1 to evaluate light fastness. Went. The results are shown in Table 4 below.

From Table 4 above, an image formed by a thermal transfer method using a thermal transfer image-receiving sheet having a heat insulating layer containing a hollow polymer and an emulsion and a thermal transfer cover film containing an ultraviolet absorber in a transparent resin layer is particularly light. It was confirmed that the robustness is high.

Production Example 6 (Production of thermal transfer image-receiving sheets R501 and R502)
(Preparation of support body 501)
50 parts by mass of LBKP (hardwood bleached kraft pulp) made of acacia and 50 parts by mass of LBKP made of aspen were each beaten to 300 ml of Canadian freeness by a disc refiner to prepare a pulp slurry.
In the obtained pulp slurry, 1.3% of cation-modified starch (CAT0304L manufactured by NSC Japan), 0.15% of anionic polyacrylamide (DA4104 manufactured by Seiko PMC), and alkyl ketene dimer (produced by Arakawa Chemical Co., Ltd.) per pulp. Size pine K) 29%, 0.29% epoxidized behenamide, 0.32% polyamide polyamine epichlorohydrin (Arakawa Chemical Co., Ltd .: Arafix 100) was added, followed by 0.12% antifoaming agent. .

The pulp slurry prepared as described above was subjected to paper making with a long net paper machine, and the felt surface of the web was pressed against a drum dryer cylinder via a dryer canvas and dried. At this time, drying was performed by setting the tensile force of the dryer canvas to 1.6 kg / cm. Thereafter, 1 g / m ² of polyvinyl alcohol (manufactured by Kuraray Co., Ltd .: KL-118) was applied to both sides of the base paper with a size press and dried, followed by calendar treatment. The base paper was made with a basis weight of 157 g / m ² to obtain a base paper (base paper) having a thickness of 160 μm.

After performing corona discharge treatment on the wire surface (back surface) side of the obtained base paper, MFR (melt flow rate; hereinafter the same) 16.0 g / 10 min, density 0.96 g / cm using a melt extruder. ³ high density polyethylene (hydrotalcite (trade name DHT-4A, manufactured by Kyowa Chemical Industry Co., Ltd.) 250 ppm, secondary antioxidant (tris (2,4-di-tert-butylphenyl) phosphite, product) Name: Irgaphos 168, manufactured by Ciba Specialty Chemicals Co., Ltd., containing 200 ppm) and MFR 4.0 g / 10 min, low density polyethylene having a density of 0.93 g / cm ³ , 75/25 (mass ratio) The resin composition blended at a ratio of 1 to ² was coated to a thickness of 21 g / m ² to form a thermoplastic resin layer comprising a mat surface (hereinafter, this thermoplastic resin layer). The surface is referred to as “rear surface.”) The thermoplastic resin layer on the rear surface side is further subjected to corona discharge treatment, and then, as an antistatic agent, aluminum oxide (“Alumina Zir 100” manufactured by Nissan Chemical Industries, Ltd.) and silicon dioxide (manufactured by Nissan Chemical Industries, Ltd. of "Snowtex O") and a 1: dispersion dispersed in water at 2 weight ratio, dry mass was coated to a 0.2 g / m ^2. followed by a corona treatment on the surface MFR 4.0 g / 10 min with 10 wt% of titanium oxide, coated with a melt extruder so that the low-density polyethylene having a density of 0.93 g / m ² to 27 g / m ² Then, a thermoplastic resin layer having a mirror surface was formed.

(Preparation of thermal transfer image receiving sheets R501 and R502)
Thermal transfer image-receiving sheets R501 and R502 were prepared in the same manner except that the support was changed from synthetic paper to the above-described support 501 in the method for manufacturing the thermal transfer image-receiving sheets R401 and R402 of Production Example 5.

Example 5 (Image formation and evaluation)
The images obtained using the heat-sensitive transfer image-receiving sheets R501 and R502 produced in Production Example 6 were finer in graininess and whiter than the images obtained using R401 and R402.

  According to the image forming method of the present invention, an image having high density, high image quality, and excellent fastness can be formed. In particular, if a heat-sensitive transfer image-receiving sheet in which a receiving layer is formed with an aqueous coating solution containing a water-soluble polymer or the like for the purpose of imparting high-speed coating suitability is used as a transfer target, a water-soluble polymer or the like contained in the receiving layer Since light fastness that is reduced by the influence of the additive can be compensated, it is possible to achieve both high-speed coating suitability and light fastness of the formed image. The image forming method of the present invention is also effectively used for full color image formation. Therefore, the present invention has high industrial applicability.

Claims (12)

A heat-sensitive transfer cover film provided with a transparent resin layer on the base film so as to be peelable, and further provided with a heat-sensitive adhesive layer thereon, and containing the ultraviolet absorber in the transparent resin layer or the heat-sensitive adhesive layer; A thermal transfer image-receiving sheet provided on a support with at least one receptor layer containing a polymer latex of at least two kinds of vinyl chloride acrylic copolymers having different chemical structures of monomers of the acrylic part and a water-soluble polymer, The heat-sensitive adhesive layer of the heat-sensitive transfer cover film and the heat-sensitive transfer image-receiving sheet are laminated so that the heat-sensitive adhesive layer faces each other, and heated from the base film side of the heat-sensitive transfer cover film by a thermal head, The layer is transferred and adhered to the heat-sensitive transfer image-receiving sheet, and the transparent resin layer other than the heated portion is peeled off from the heat-sensitive transfer image-receiving sheet together with the base film. Image forming method characterized by comprising the step of. The image forming method according to claim 1, wherein the heat-sensitive adhesive layer contains a resin having a glass transition temperature of 40 to 75 ° C. The image forming method according to claim 1 or 2 wherein the water soluble polymer of the receiving layer is characterized in that it is a gelatin. The thermal transfer image-receiving sheet contains a non-foamed hollow polymer having a particle size of 0.1 to 2 μm and formed of polystyrene resin, acrylic resin or styrene-acrylic resin between the support and the receiving layer. It has a heat insulation layer, The image forming method of any one of Claims 1-3 characterized by the above-mentioned. The image forming method according to claim 4 , wherein the heat insulating layer contains a water-soluble polymer. The image forming method according to claim 4 or 5, characterized in that it contains gelatin into the heat insulating layer. The transparent resin layer is a polyester resin, polystyrene resin, acrylic resin, polyurethane resins, acrylic urethane resins, and the claims 1-6, characterized by containing a resin selected from silicone-modified resin of each of these resins The image forming method according to any one of the above. The heat-sensitive adhesive layer, an acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, according to claim 1-7, characterized by containing a resin selected from vinyl copolymer resin of vinyl chloride, acetate and polyester resin The image forming method according to any one of the above. The image forming method according to any one of claims 1-8 wherein the heat-sensitive transfer image-receiving sheet, characterized in that it contains further emulsifying dispersion. The receiving layer, the image forming method according to any one of claims 1-8, characterized in that it further comprises an emulsified dispersion. The image forming method according to any one of claims 4 to 10 , wherein the heat insulating layer further contains an emulsified dispersion. During the emulsified dispersion, the image forming method according to any one of claims 9-11, characterized in that it contains an image hardening agent or an ultraviolet absorber.