JP2003145937A - Material for laser melting thermal transfer recording and method for forming image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a proof which improves the light-resistance of a printed matter outputted by DDCP (direct digital color proof) and of which the color changes very little even in a long-time storage. SOLUTION: An ink layer of an ink sheet used by a laser melting thermal transfer system contains at least one of an ultraviolet absorber, an antioxidant and a light stabilizer. An image receiving layer of an intermediate transfer medium used by the laser melting thermal transfer system wherein an image is re-transfer onto a final image carrier after recorded by a laser contains at least one of the ultraviolet absorber, the antioxidant and the light stabilizer. The present method for forming the image by the laser melting thermal transfer system uses either the ink sheet or the intermediate transfer medium, or a combination of both of them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser melting thermal transfer recording material (ink sheet and intermediate transfer medium) used in a heat mode laser recording method for obtaining a high-definition image by using a laser beam, and more particularly to DDCP (direct transfer). A laser melting thermal transfer recording material useful for making a digital color proof).

[0002]

2. Description of the Related Art In the field of graphic arts,
With the introduction of CTP (Computer to Plate), by directly inputting digital data, as a digital color proof that can obtain an output equivalent to printed matter, a high-definition image is output by laser light D
DCP has been proposed. Among them, the laser thermal transfer recording method using the same pigment as that used for printing has attracted attention as a high-definition proof because it can obtain color tones equivalent to those printed on actual printing paper, can be calibrated, and can reproduce halftone dots. Is coming.

Conventionally, since the proof output by the DDCP does not require long-term storability, the influence of light and heat upon fading on the image when stored is considerably smaller than that of the sublimation method or the ink jet method. It has been ignored in laser thermal transfer systems. However, in recent years, DDCP
The color proof of the proof output in the same way as the standard printed matter,
In order to use as a standard image used in color management (CMS) or the like, an output product having less color variation during storage and better light resistance has been demanded.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of such a situation, and an object of the present invention is to improve the light fastness of a printed matter output by a DDCP, and to keep color even when stored for a long time. It is to provide a proof with extremely small fluctuation.

[0005]

The above objects of the present invention can be achieved by the following constitutions.

1) The ink layer of the ink sheet used in the laser melting thermal transfer system is composed of an ultraviolet absorber, an antioxidant,
An ink sheet containing at least one light stabilizer.

2) The ink sheet according to 1), wherein the ink sheet has at least a photothermal conversion layer and an ink layer containing a pigment.

3) The image receiving layer of the intermediate transfer medium used in the laser fusion thermal transfer system in which an image is recorded with a laser and then retransferred to the final image bearing member, at least one of an ultraviolet absorber, an antioxidant and a light stabilizer is used. An intermediate transfer medium containing one.

4) An image forming method by a laser melting thermal transfer system using one of the ink sheet described in 1) and the intermediate transfer medium described in 3).

5) An image forming method by a laser fusion thermal transfer system using the ink sheet described in 1) and the intermediate transfer medium described in 3) in combination.

The present invention will be described in more detail below. A feature of the present invention is that an ultraviolet absorber, a light stabilizer, and an antioxidant are provided in an ink layer of an ink sheet and / or an image receiving layer of an intermediate transfer medium in order to prevent discoloration of an image and yellowing of a binder resin. Of at least one of

As the ultraviolet absorber, benzoic acid ester and its derivative, cinnamic acid ester and its derivative, salicylic acid derivative, benzaldehyde derivative, chroman and carbostyryl compound, acrylonitrile compound,
Substituted acrylonitrile compound, benzalazine compound, benzimidazole compound, benzotriazole compound, 4-thiazolidone compound, benzophenone compound, benzoate compound, cyanoacrylate compound, salicylate compound, UV absorbing polymer, metal oxide Etc.

Examples of the metal oxide used as the ultraviolet absorber include silica, cerium oxide, iron oxide, aluminum oxide, zinc oxide, barium sulfate, magnesium oxide, titanium oxide, zircon oxide, calcium carbonate and the like. When the metal oxide is added to the ink layer, it is preferable that the hue of the ink does not change significantly, and when it is added to the image receiving layer, the image receiving layer becomes transparent and is preferably transparent.
Since the transparency of the metal oxide can be obtained by controlling the wavelength to be half the wavelength of light or less, the particle diameter of the metal oxide is 20.
It is preferably 0 nm or less, more preferably 100 nm or less.

As the light stabilizer, hindered amine compounds, nickel chelate compounds (quencher),
Other various chelating agents and the like can be mentioned.

As the antioxidant, a chroman compound,
Claman-based compounds, hydroquinone derivatives, phenol-based compounds, monophenol-based compounds, bisphenol-based compounds, hindered phenol-based compounds, spirobiindane-based compounds, thioether-based compounds, amine compounds and other primary antioxidants (radical scavengers), Alternatively, a sulfur-based or phosphorus-based secondary antioxidant (hydroperoxide stabilizer) may be used.

One or more of these ultraviolet absorbers, antioxidants and light stabilizers may be used in combination.
In order to prevent color change of the color material of the ink layer, in particular, an antioxidant and a light stabilizer are added to the ink layer, and an ultraviolet absorber is added to the image receiving layer because the image receiving layer becomes an image protective layer after secondary transfer. Is particularly preferable.

The amount of addition to the ink layer of the ink sheet and the image receiving layer of the intermediate transfer medium is 0.1 to 0.1% of the antioxidant and the light stabilizer with respect to the binder resin of the ink layer and the image receiving layer.
It is preferable to add 30% by mass, more preferably 0.5 to 20% by mass, and 10 to 90% by mass, especially about 10 to 70% by mass of the ultraviolet absorber. Further, these ultraviolet absorbers, antioxidants and light stabilizers may be sprayed onto the surface of the ink layer, the surface of the image receiving layer and the surface of the image receiving layer after secondary transfer by a known method.

A final image bearing member obtained by retransferring an image formed by a laser melting thermal transfer system using the ink sheet or the intermediate transfer medium to which the above-mentioned ultraviolet absorber, antioxidant and light stabilizer are added, alone or in combination ( The color variation during storage of paper, polyethylene terephthalate, etc. is preferably less than 1 in ΔE, more preferably less than 0.5.

Hereinafter, the ink sheet, the intermediate transfer medium and the image forming method will be sequentially described. The ink sheet used in the present invention is a film having a light-heat conversion function and an ink (pigment) transfer function, and has a light-heat conversion layer having at least a light-heat conversion function and an ink layer on one surface of a support. It is also possible to impart both functions to the same layer. If necessary, a cushion layer, an easy-adhesion layer, a release layer, or the like may be provided between these layers and the support, and a back coat layer may be provided on the surface opposite to these layers.

As the binder used in the back coat layer, gelatin, polyvinyl alcohol, methyl cellulose, nitrocellulose, acetyl cellulose, aromatic polyamide resin, silicone resin, epoxy resin, alkyd resin, phenol resin, melamine resin, fluororesin, polyimide. Resin, urethane resin, acrylic resin, urethane modified silicone resin, polyethylene resin, polypropylene resin, polyester resin, Teflon (R) resin, polyvinyl butyral resin, vinyl chloride resin, polyvinyl acetate, polycarbonate, organic boron compound, aromatic ester General-purpose polymers such as polyurethane, fluorinated polyurethane and polyether sulfone can be used.

Crosslinking using a crosslinkable water-soluble binder as the binder of the backcoat layer is effective in preventing the matting material from falling off and improving the scratch resistance of the backcoat. It is also effective in blocking during storage.
As the cross-linking means, any one of heat, actinic rays and pressure or a combination thereof can be adopted without any particular limitation, depending on the characteristics of the cross-linking agent used. In some cases, an optional adhesive layer may be provided on the side of the support on which the backcoat layer is provided in order to impart adhesiveness to the support.

It is preferable that the back coat layer contains a mat material. As the matting material preferably added to the back coat layer, organic or inorganic fine particles can be used. As the organic matting material, fine particles of polymethylmethacrylate (PMMA), polystyrene (PS), polyethylene (PE), polypropylene (PP), other radical polymerization type polymer, fine particles of condensation polymer such as polyester and polycarbonate (PC), etc. Is mentioned. The back coat layer is preferably provided with a coating amount of about 0.5 to 5 g / m ² . If it is less than 0.5 g / m ² , the coating property is unstable and problems such as powder drop of the mat material are likely to occur. Further, when it is applied over 5 g / m ² , the suitable particle diameter of the matting material becomes very large, and the ink layer surface is embossed by the back coat during storage. Especially, the thermal transfer for transferring a thin ink layer. In this case, the recorded image is likely to be missing or uneven.

The number average particle size of the mat material is preferably 1 to 20 μm larger than the film thickness of only the binder of the back coat layer. Among the mat materials, particles having a particle size of 2 μm or more are required to be 1 mg / m ² or more, preferably 2 to 6
It is 00 mg / m ² . This improves especially foreign matter failures. Further, by using a narrow particle size distribution such that a value σ / rn (= coefficient of variation of particle size distribution) obtained by dividing the standard deviation of the particle size distribution by the number average particle size is 0.3 or less, Defects caused by particles having an abnormally large particle size can be improved, and desired performance can be obtained with a smaller addition amount. More preferably, this coefficient of variation is 0.15 or less.

In order to prevent foreign matter from adhering to the back coat layer due to frictional charging with the transport roll when the sheet is supplied,
It is preferable to add an antistatic agent. As the antistatic agent, a cationic surfactant, an anionic surfactant,
In addition to nonionic surfactants, polymeric antistatic agents, conductive fine particles, "11290 chemical products" (supra) 875-8
The compounds described on page 76 are widely used.

The support of the ink sheet may be any one as long as it has rigidity, good dimensional stability, excellent smoothness, transmits laser light used for recording, and can withstand heat during image formation. Specifically, various papers such as paper, coated paper, synthetic paper (polypropylene, polystyrene, or a composite material obtained by laminating them with paper), vinyl chloride resin sheet, ABS resin sheet, polyethylene terephthalate (PET) Film, polybutylene terephthalate film, polyethylene naphthalate (PEN) film,
Polyacrylate film, polycarbonate (PC)
Film, polyetherketone film, polysulfone film, polyethersulfone film, polyetherimide film, polyimide film, polyethylene (PE) film, polypropylene (PP) film,
Made of polystyrene (PS) film, syndiotactic polystyrene, stretched nylon (Ny) film, polyacetate film, polymethylmethacrylate film, etc. single layer or various plastic films or sheets in which two or more layers are laminated, or various metals Film or sheet, a film or sheet formed of various ceramics, a metal plate of aluminum, stainless steel, chromium, nickel or the like, a resin-coated paper laminated or vapor-deposited with a metal thin film, and the like. .

These supports may be subjected to various processing such as dimensional stabilization and antistatic. Examples of antistatic agents include cationic surfactants, anionic surfactants, nonionic surfactants, polymeric antistatic agents, conductive fine particles, and “11290 chemical products”, Chemical Industry Daily, 87
The compounds described on pages 5 to 876 are widely used.

Further, the support may be subjected to a conventionally known surface modification treatment. Examples of these surface modification treatments include flame radiation treatment, sulfuric acid treatment, corona discharge treatment, plasma treatment, glow discharge treatment and the like.

Further, an adhesive layer may be provided on the support so that each of the layers described below can be well coated on the support. As the adhesive layer, conventionally known materials can be used without particular limitation. Examples of the method for providing the adhesive layer include water-based resin coating, solvent-based resin coating, water-based latex coating, hot melt coating and the like. Generally, it is advantageous to provide an adhesive layer at the time of producing the support from the viewpoint of cost and stability, and from this point, for example, acrylic resin, polystyrene resin, polyester resin, urethane resin, polyethylene / vinyl acetate resin, A method of applying a latex such as a styrene resin is preferable, but not limited to this. Base films with such an adhesive layer are sold by various companies, and these can be preferably used.

If an image is formed by irradiating a laser beam from the ink sheet side, it is desirable that the support of the ink sheet is transparent.

The thickness of the support of the ink sheet is preferably thinner than that of the intermediate transfer medium, and is preferably about 30 to 150 μm, and more preferably 50 to 100 μm from the viewpoint of easy superposition.

A cushion layer or a support having a cushioning property may be used between the support and the photothermal conversion layer for the purpose of enhancing the adhesion between the ink sheet and the intermediate transfer medium during exposure.

Although the preferable characteristics of the cushion layer cannot necessarily be defined only by the type of material, the preferable characteristics of the material itself include polyolefin resin,
Ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polybutadiene resin, styrene-butadiene copolymer (SBR), styrene-ethylene-butene-styrene copolymer (SEBS), acrylonitrile-butadiene copolymer ( NBR), polyisoprene resin (IR), styrene-isoprene copolymer (SI
S), acrylic acid ester copolymer, polyester resin, vinyl chloride vinyl chloride resin, polyurethane resin, acrylic resin,
Butyl rubber, polynorbornene and the like can be mentioned. Among these, those having a relatively low molecular weight are likely to satisfy the requirements of the present invention, but they are not necessarily limited in relation to the material.

The cushion layer can be provided by solvent coating, but it can also be coated and formed in the state of an aqueous dispersion such as latex or emulsion. In addition to this, a water-soluble resin can also be used. These resins can be used alone or as a mixture, if necessary.

In addition, materials other than those mentioned above can be added with various additives to impart preferable characteristics to the cushion layer. Examples of such additives include low melting point substances such as wax and plasticizers. Specific examples thereof include phthalic acid ester, adipic acid ester, glycol ester, fatty acid ester, phosphoric acid ester and chlorinated paraffin. Further, for example, various additives described in "Practical Handbook of Additives for Plastics and Rubbers", Kagaku Kogyo Co., Ltd. (published in 1970) and the like can be added. The amount of these additives to be added may be selected in such an amount that the preferable physical properties can be expressed in combination with the cushion layer material serving as a base, and is not particularly limited. 10% by mass or less, more preferably 5% by mass or less.

As a method for forming the cushion layer, a material obtained by dissolving the above materials in a solvent or dispersing them in a latex form is applied by a blade coater, a roll coater, a bar coater, a curtain coater, a gravure coater, or the like, and extrusion lamination by hot melt. Laws can be applied.
Further, as the special cushion layer, it is also possible to use a resin layer having a void structure obtained by foaming a thermosoftening or thermoplastic resin.

The thickness of the cushion layer is preferably 0.5 to 10 μm, more preferably 1 to 7 μm.

As the light-heat conversion substance, there is known Japanese Patent Laid-Open No. 2000-3.
55176, the compound described in the "0053" photothermal conversion layer, more specifically, JP-A-63-139191;
64-33547, JP-A-1-160683, 2-2074, 3-26593, 3-3099.
No. 1, No. 3-36094, No. 3-36095, No. 3
-42281, 3-97589, 3-1034
No. 76 and the like.

Inorganic materials such as metal materials can also be used as the photothermal conversion substance. The metallic material is used in the form of particles (for example, blackened silver). The optical density of the photothermal conversion substance at the laser absorption wavelength is preferably 0.1 to 2.0,
0.3 to 1.2 is more preferable. The optical density is 0.1
If it is less than 1.0, the sensitivity of the thermal transfer material may be lowered, and if it exceeds 2.0, it may be disadvantageous in cost.

As the binder polymer for the photothermal conversion layer, a resin having a high glass transition point (Tg) and a high thermal conductivity,
For example, polymethylmethacrylate, polycarbonate, polystyrene, ethylcellulose, nitrocellulose, polyvinyl alcohol, gelatin, polyvinylpyrrolidone, polyparabanic acid, polyvinyl chloride, polyamide, polyimide, polyetherimide, polysulfone, polyethersulfone, aramid, etc. A heat resistant resin can be used. Above all, when a plurality of high-power lasers such as multimode lasers are arranged and recorded, a polymer having excellent heat resistance is preferable and Tg is 150.
~ 400 ° C and 5% mass reduction temperature Td (TGA method,
A polymer having a temperature increase rate of 10 ° C./min in air) of 250 ° C. or higher is more preferable, and Tg is 220 to 400 ° C.
Most preferably, the polymer has a Td of 400 ° C. or higher.

The light-to-heat conversion layer is provided by preparing a coating solution (light-to-heat conversion layer coating solution) in which a light-to-heat conversion substance and a binder polymer of the light-to-heat conversion layer are prepared, and coating and drying this on a support. it can. Examples of the organic solvent for dissolving the binder polymer in the photothermal conversion layer include 1,4-
Examples include dioxane, 1,3-dioxolane, dimethyl acetate, N-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethylformamide, γ-butyrolactone and the like.

The coating method for coating the photothermal conversion layer coating liquid can be appropriately selected from known coating methods. Drying is usually performed at a temperature of 300 ° C. or lower.
Preferably, the drying temperature is 200 ° C. or lower, and when polyethylene terephthalate is used as the support,
More preferably, it is in the range of 80 to 150 ° C.

In the photothermal conversion layer formed as described above, the solid content mass ratio of the photothermal conversion substance and the binder polymer of the photothermal conversion layer (photothermal conversion substance: binder) is 1:20 to.
2: 1 is preferable and 1:10 to 2: 1 is more preferable.
When the amount of the binder is too small, the cohesive force of the photothermal conversion layer is reduced, and when the formed image is transferred to the thermal transfer image receiving material, the photothermal conversion layer is easily transferred together, which may cause color mixing of the image. , If the amount of binder is too large, the layer thickness of the photothermal conversion layer increases in order to achieve a certain light absorption rate,
The sensitivity may be reduced.

The photothermal conversion layer has a layer thickness of 0.03 to
0.8 μm is preferable, and 0.05 to 0.3 μm is more preferable. Further, the light-heat conversion layer has a range of 0.1 to 1.3 (preferably 0.2 to 1.
It is preferable to have the maximum of the absorbance (optical density = OD) of 1).

The heat resistance (heat distortion temperature, thermal decomposition temperature, etc.) of the photothermal conversion layer binder polymer is preferably higher than the heat resistance of the material used for the layer provided on the photothermal conversion layer.

A water-soluble polymer can also be used as the binder in the photothermal conversion layer. The water-soluble polymer is preferable because it has good releasability from the ink layer, good heat resistance upon laser irradiation, and little so-called scattering even with excessive heating. When a water-soluble polymer is used, it is desirable that the photothermal conversion substance be modified to be water-soluble (by introduction of a sulfo group) or dispersed in water. Further, by incorporating various releasing agents into the photothermal conversion layer, the peelability between the photothermal conversion layer and the ink layer can be improved and the sensitivity can be improved. As the release agent, silicone-based release agents (polyoxyalkylene-modified silicone oil, alcohol-modified silicone oil, etc.), fluorine-based surfactants (perfluorophosphate ester-based surfactants, etc.), and various other surface-active agents Agents etc. are effective.

On the light-heat conversion layer of the ink sheet, gas is generated by the action of heat generated in the light-heat conversion layer, or adhering water or the like is released, whereby bonding between the light-heat conversion layer and the image forming layer is achieved. A heat-sensitive release layer containing a heat-sensitive material that weakens the strength can be provided. Examples of the heat-sensitive material include a compound (polymer or low-molecular compound) which itself decomposes or deteriorates to generate gas, or a compound (polymer or low-molecular compound) which absorbs or adsorbs a considerable amount of easily vaporizable gas such as water. Molecular compound) and the like can be used. You may use these together.

Examples of the polymer which decomposes or deteriorates by heat to generate a gas include self-oxidizing polymers such as nitrocellulose, chlorinated polyolefin, chlorinated rubber, polychlorinated rubber, polyvinyl chloride and polyvinylidene chloride. Such halogen-containing polymers, acrylic polymers such as poly-i-butylmethacrylate in which volatile compounds such as water are adsorbed, cellulose esters such as ethyl cellulose in which volatile compounds such as water are adsorbed, volatilization of water, etc. Examples thereof include natural polymer compounds such as gelatin to which a hydrophilic compound is adsorbed. Examples of the low molecular weight compound that decomposes or deteriorates by heat to generate a gas include a compound such as a diazo compound or an azide compound that generates a gas by exothermic decomposition. In addition, it is preferable that the above-mentioned decomposition or deterioration of the heat-sensitive material occurs at 280 ° C. or less, and particularly 23
It preferably occurs at 0 ° C. or lower.

When a low molecular weight compound is used as the heat sensitive material, it is desirable to combine it with a binder. As the binder, it is possible to use the above-mentioned polymer which itself decomposes or deteriorates by heat to generate a gas, and a general polymer binder which does not have such a property.

When a heat-sensitive low molecular weight compound and a binder are used in combination, the mass ratio of the former to the latter is 0.0.
It is preferably 2: 1 to 3: 1 and more preferably 0.05: 1 to 2: 1. It is preferable that the heat-sensitive peeling layer and the photothermal conversion layer are coated over almost the entire surface, and the layer thickness is generally 0.03 to 1 μm, and among them, 0.05 to
0.5 μm is preferable.

The ink layer is mainly composed of a colorant and a thermoplastic binder. In laser melt thermal transfer, the ink layer is a layer that can be transferred together with the layer containing the colorant and the binder by melting or softening when heated, and it is not necessary to transfer in a completely melted state.

In order to reduce the color variation after storage after the secondary transfer to paper and to improve the light resistance and heat resistance, a pigment having high light resistance and heat resistance that can be used for the ink layer is used. More preferably. As a pigment with good light resistance, inorganic pigments such as titanium oxide, zinc white, carbon black, graphite, iron black, red iron oxide, red lead, molybdate orange,
Examples thereof include yellow lead, yellow iron oxide, titanium yellow, chrome green, chromium oxide, ultramarine blue, manganese purple, aluminum powder, bronze powder and mica.

Further, as a red pigment of organic pigment, permanent red FGR (CI Pigment Re
d 112), permanent carmine FB (C.I.P.
igment Red 5), Permanent Red FR
(C.I. Pigment Red 21), Permanent Red FRL (C.I. Pigment Red
2), Brilliant Carmine (C.I. Pigment)
Red 114), permanent carmine FB (C.
I. Pigment Red 5), Permanent Carmine FBB (CI Pigment Red 14)
6), Nova Palm Red F3RK, F5RK (C.I.
Pigment Red 170), Nova Palm Red HFG (CI Pigment Orange 3)
8), Nova Palm Red HF4B (C.I. Pigme
nt Red 187), toluidine red, naphthol carmine, permanent carmine, naphthol red,
Condensed azo red 214, condensed azo scarlet 242,
Examples thereof include quinacridone magenta, quinacridone maroon, quinacridin scarlet, pyranthrone red, dibrom zanzanthuron red, thioindigo bordeaux, perylene red 190, perylene scarlet and perylene red 224.

Organic pigments such as orange and yellow pigments include Novapalm Orange HL, Benzimidazolone Orange,
Quinacridone Gold, Perinone Orange, Fast Yellow G (CI Pigment Yellow)
1), Fast Yellow 10G (C.I. Pigmen
t Yellow 3), Disazo Yellow 11R, Condensed Azo Yellow 3G, Fast Yellow FGL (C.T.
I. Pigment Yellow 97), Fast Yellow ER, A-3 Yellow (C.I. Pigmen
t Yellow 167), Poster Palm Yellow H
3G (CI Pigment Yellow 15
4), copper azomethine yellow 117, copper azomethine yellow 129, benzimidazolone yellow H4G, benzimidazolone yellow H3G, benzimidazolone yellow HLR, isoindolinone yellow 2GLT, isoindolinone yellow 3RLT, isoindolinone yellow 139, Examples include anthrapyrimidine yellow, flavantron yellow, quinophthalone yellow, and the like.

Further, as the organic type green pigment, nickel azo yellow, phthalocyanine green, salt brominated copper phthalocyanine green, etc., as blue color, phthalocyanine blue, metal-free phthalocyanine blue, indanthrone blue, etc., and as purple pigment, , Quinacridone red, dioxazine violet and the like.

When used as a color proof as in the present invention, yellow is a compound containing an isoindoline ring, PY-180, C.I. I. 21095 or C.I. I. 21
090; magenta is C.I. I. 15850: 1, C.I. I.
Pigment Red 57: 1, M-122; cyan is C.I. I. The 74160 pigment is particularly preferred.

The content of these pigments is preferably in the range of 5 to 70% by mass, and more preferably 10 to 60% by mass, based on the total solid content of the ink layer coating liquid.

As the binder contained in the ink layer,
Those having a softening point of 40 to 150 ° C., for example, butyral resin, polyamide resin, polyethyleneimine resin,
Sulfonamide resin, polyester polyol resin, petroleum resin, styrene, vinyltoluene, α-methylstyrene, 2-methylstyrene, chlorostyrene, vinylbenzoic acid, sodium vinylbenzenesulfonate, styrene such as aminostyrene, and derivatives and substituted products thereof. Homopolymers and copolymers, methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, and hydroxyethyl methacrylate, and acrylic acid esters such as methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, α-ethylhexyl acrylate, and Dienes such as acrylic acid, butadiene, isoprene, acrylonitrile, vinyl ethers, maleic acid and maleic acid esters, maleic anhydride, cinnamic acid, salts Examples thereof include vinyl monomers such as vinyl chloride and vinyl acetate, and copolymers with other monomers such as vinyl monomers. These resins may be used as a mixture of two or more kinds.

In addition to the above-mentioned thermoplastic binders, elastomers such as natural rubber, styrene-butadiene rubber, isoprene rubber, chloroprene rubber and diene copolymers,
It is also possible to add a rosin derivative such as rosin maleic acid resin, rosin phenol resin and hydrogenated rosin, and a polymer compound such as phenol resin, terpene resin, cyclopentadiene resin and aromatic hydrocarbon resin.

The content of the thermoplastic binder is preferably 70 to 30% by mass, more preferably 60 to 40% by mass, based on the total solid content of the ink layer.

When a multicolor image is produced by repeatedly superposing a large number of image layers (ink layers on which images are formed) on the same thermal transfer image receiving material, the ink layers are formed in order to enhance the adhesion between the images. It is also preferred to include a plasticizer. Examples of the plasticizer include phthalates such as dibutyl phthalate, dioctyl phthalate, di (2-ethylhexyl) phthalate, dinonyl phthalate, dilauryl phthalate, butyl lauryl phthalate, and butyl benzyl phthalate;
Aliphatic dibasic acid esters such as di (2-ethylhexyl) adipate and di (2-ethylhexyl) sebacate;
Phosphoric acid triesters such as tricresyl phosphate and tri (2-ethylhexyl) phosphate; polyol polyesters such as polyethylene glycol ester; and epoxy compounds such as epoxy fatty acid ester.

In addition to the above-mentioned general plasticizers, polyethylene glycol dimethacrylate, 1,2,4-butanetriol trimethacrylate, trimethylolethane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, diester. Acrylic acid esters such as pentaerythritol-polyacrylate can also be preferably used in combination depending on the kind of binder used. In addition, you may use a plasticizer in combination of 2 or more type.

The addition amount of the above-mentioned plasticizer is generally such that the content ratio (mass ratio) of the total amount of the pigment and the polymer binder to the plasticizer in the image forming layer is 100: 0.5 to.
1: 1 is preferable and 100: 2-3: 1 is more preferable.

Further, in addition to the above components, a surfactant, a viscosity improver and the like can be added to the ink layer, if necessary. The layer thickness (dry layer thickness) of the ink layer is 0.2 to 1.5 μm
Is preferable, and 0.3-1.0 μm is more preferable.

Next, the intermediate transfer medium will be described. The intermediate transfer medium has a structure in which a cushion layer and an image receiving layer are sequentially laminated on one surface of a support, and has a back coat layer on the other surface as necessary. A peeling layer (intermediate layer) may be provided between the image receiving layer and the cushion layer.

A back coat layer is provided on the back surface of the support (the surface opposite to the surface provided with the image receiving layer) in order to impart functions such as running stability, heat resistance and antistatic property. preferable. The back coat layer has a binder resin dissolved in a solvent, or a binder resin and a particle size of 2 to 30 μm.
It can be formed by coating the back surface of the support with a coating solution for the back coat layer, which is obtained by dissolving or dispersing the matting material in the above.

As the binder used in the back coat layer, gelatin, polyvinyl alcohol, methyl cellulose, nitrocellulose, acetyl cellulose, aromatic polyamide resin, silicone resin, epoxy resin, alkyd resin, phenol resin, melamine resin, fluorine resin, polyimide. Resin, urethane resin, acrylic resin, urethane modified silicone resin, polyethylene resin, polypropylene resin, polyester resin, Teflon (R) resin, polyvinyl butyral resin, vinyl chloride resin, polyvinyl acetate, polycarbonate, organic boron compound, aromatic ester General-purpose polymers such as fluorinated polyurethane and polyether sulfone can be used.

The use of a crosslinkable water-soluble binder as a binder is effective in preventing the matting material from falling off and improving the scratch resistance of the back coat. It is also effective in blocking during storage. This crosslinking means
Depending on the characteristics of the crosslinking agent used, any one of heat, actinic rays and pressure or a combination thereof can be adopted without particular limitation. In some cases, an optional adhesive layer may be provided on the side of the support on which the backcoat layer is provided in order to impart adhesiveness to the support. Further, it is preferable that the back coat layer contains a mat material. As the matting material preferably added to the back coat layer, organic or inorganic fine particles can be used. Examples of the organic matting material include fine particles of polymethylmethacrylate (PMMA), polystyrene, polyethylene, polypropylene and other radical polymerization type polymers, fine particles of condensation polymers such as polyester and polycarbonate, fine particles of fluorine resin and silicon resin. . Crosslinked organic fine particles are more preferable in order to increase the strength and solvent resistance of the particles.

The back coat layer is preferably provided in an amount of about 0.5 to 5 g / m ² . If it is less than 0.5 g / m ² , the coating property is unstable and problems such as powder drop of the mat material are likely to occur. Further, when it is applied over 5 g / m ² , the suitable particle diameter of the matting material becomes very large, and the back coat causes embossing of the ink layer surface. Especially, in thermal transfer for transferring a thin ink layer. A printed image is likely to be missing or uneven.

The number average particle diameter of the mat material is preferably 1 to 20 μm larger than the film thickness of only the binder of the back coat layer. Among the mat materials, particles having a particle size of 2 μm or more are required to be 5 mg / m ² or more, preferably 6 to
It is 600 mg / m ² . This improves especially foreign matter failures. Also, by using a narrow particle size distribution such that the value σ / rn (= coefficient of variation of particle size distribution) obtained by dividing the standard deviation of the particle size distribution by the number average particle size is 0.3 or less, Defects caused by particles having a very large particle size can be improved, and desired performance can be obtained with a smaller addition amount. More preferably, this coefficient of variation is 0.15 or less.
Further, a surfactant or the like may be added.

An antistatic agent is used in the back coat layer in order to prevent triboelectrification. Examples of the antistatic agent include cationic surfactants, anionic surfactants, nonionic surfactants, polymeric antistatic agents, conductive fine particles, and “11290 chemical products”, Chemical Industry Daily, 87
The compounds described on pages 5 to 876 are widely used.

Among the above-mentioned substances, metal oxides such as carbon black, graphite, tin oxide, zinc oxide and titanium oxide, and conductive fine particles such as organic semiconductors are preferably used as the antistatic agent which can be used in the back coat layer. To be In particular, the use of conductive fine particles is preferable because the antistatic agent is not dissociated from the backcoat layer and a stable antistatic effect is obtained regardless of the environment such as temperature.

The above antistatic agent is preferably added to the back coat layer in order to prevent foreign matter from adhering to the back coat layer due to frictional charging with the transport roll. The amount of antistatic agent added is
The surface resistivity of the layer or support of the intermediate transfer medium at 80% HD (relative humidity) or less is 10 ⁸ to 10 ¹² Ω /
It is preferable to mix so as to have m ² .

As the support of the intermediate transfer medium, any support may be used as long as it has good dimensional stability and can withstand heat during image formation. The films or sheets described in the rows can be used.

The support preferably has rigidity and flexibility suitable for transportation. The preferred film thickness for the support is 25
To 200 μm, more preferably 50 to 125 μm
Is.

The intermediate transfer medium of the present invention is preferably provided with a cushion layer in order to improve the reduced pressure adhesion to the ink sheet. The cushion layer is a layer having cushioning properties. The elastic modulus and the penetration can be used as a guideline for the cushioning property. For example,
A layer having a modulus of elasticity at 25 ° C. of about 1 to 250 kg / mm ² or a penetration of about 15 to 500 defined by JIS K2530-1976 is suitable for forming a color proof image for color proofing. However, the required degree varies depending on the intended use of the image.

The cushion layer is preferably composed of a material having a thermoplastic material such as ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polybutadiene resin, styrene-butadiene copolymer (SBR). , Styrene-ethylene-butene-styrene copolymer (SEBS), acrylonitrile-butadiene copolymer (NBR), polyisoprene resin (IR),
Examples thereof include styrene-isoprene copolymer (SIS), acrylic ester copolymer, polyester resin, polyurethane resin, acrylic resin, butyl rubber, polynorbornene and the like.

Among these, those having a relatively low molecular weight are likely to satisfy the requirements of the present invention, but they are not necessarily limited in relation to the material.

In addition, materials other than the above may be added with various additives to impart preferable characteristics to the cushion layer. Examples of such additives include low melting point substances such as wax and plasticizers. Specific examples thereof include phthalic acid ester, adipic acid ester, glycol ester, fatty acid ester, phosphoric acid ester, and chlorinated paraffin. Further, various additives described in, for example, "Practical Handbook of Additives for Plastics and Rubbers", Kagaku Kogyo Co., Ltd. (issued in 1945) and the like can be added.

The amount of these additives to be added may be selected so that the desired physical properties can be exhibited in combination with the base cushion layer material, and is not particularly limited, but generally, the cushion layer material is used. 10% by mass or less of the amount,
Further, it is preferably 5% by mass or less.

As the method for forming the cushion layer, a material obtained by dissolving the above materials in a solvent or dispersing them in a latex form is applied by a blade coater, a roll coater, a bar coater, a curtain coater, a gravure coater or the like, and extrusion lamination by hot melt. Laws can be applied.

The thickness of the cushion layer is preferably 15 μm or more, more preferably 20 μm or more. Further, in the case of retransferring to another transfer target (paper such as coated paper and high-quality paper), a film thickness of 30 μm or more is preferable. If the thickness of the cushion layer is less than 15 μm, voids or chips may occur during retransfer to the final transfer target.

The image-receiving layer comprises a binder, a matting material and various additives which are added as required. Specific examples of the binder include a polyvinyl acetate emulsion-based adhesive,
Adhesives such as chloroprene type adhesives, epoxy resin type adhesives, natural rubber, chloroprene rubber type, butyl rubber type, polyacrylic acid ester type, nitrile rubber type, polysulfide type, silicone rubber type, petroleum type resin, etc.
Recycled rubber, vinyl chloride resin, SBR, polybutadiene resin, polyisoprene, polyvinyl butyral resin, polyvinyl ether, ionomer resin, SIS, SEB
S, acrylic resin, ethylene-vinyl chloride copolymer, ethylene-acrylic copolymer, ethylene-vinyl acetate resin (EVA), vinyl chloride graft EVA resin, EVA graft vinyl chloride resin, vinyl chloride resin, various modified olefins, polyvinyl butyral Etc. The binder film thickness of the image receiving layer is preferably 0.8 to 2.5 μm.

Specific examples of the binder for the intermediate layer include polyester, polyvinyl acetal, polyvinyl formal, polyparabanic acid, polymethyl methacrylate, polycarbonate, ethyl cellulose, nitrocellulose,
Styrenes such as methyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, polyvinyl alcohol, polyvinyl chloride, polystyrene, and acrylonitrile styrene, and those obtained by crosslinking these resins, polyamides, polyimides, polyetherimides, polysulfones, polyethersulfones, Tg of aramids, etc. Is 65 ° C
The above-mentioned thermosetting resins and cured products of these resins can be mentioned. As the curing agent, general curing agents such as isocyanate and melamine can be used.

When a binder for the intermediate layer is selected in accordance with the above physical properties, polycarbonate, acetal and ethyl cellulose are preferable from the viewpoint of storability, and when an acrylic resin is used for the image receiving layer, the image after laser thermal transfer is retransferred. The peelability is good, which is particularly preferable.

Separately, a layer having extremely low adhesion to the image receiving layer upon cooling can be used as the intermediate layer.
Specifically, a layer containing a heat-melting compound such as waxes and binders or a thermoplastic resin as a main component can be used.

As the heat-fusible compound, there is disclosed in JP-A-63-1.
There are substances described in No. 93886. In particular, microcrystalline wax, paraffin wax, carnauba wax and the like are preferably used. As the thermoplastic resin, ethylene-based copolymers such as ethylene-vinyl acetate-based resin and cellulose-based resin are preferably used. In addition to these, the materials mentioned for the cushion layer can also be used.

If desired, higher fatty acids, higher alcohols, higher fatty acid esters, amides, higher amines and the like can be added as additives to such an intermediate layer.

Another constitution of the intermediate layer is a layer having a peeling property by causing cohesive failure of itself by melting or softening during heating. Such an intermediate layer preferably contains a supercooling substance.

Examples of the supercooling substance include poly-ε-caprolactone, polyoxyethylene, benzotriazole, tribenzylamine, vanillin and the like.

Further, the intermediate layer having a different constitution contains a compound which lowers the adhesiveness to the image receiving layer. Examples of such compounds include silicone-based resins such as silicone oil; fluorine-based resins such as Teflon (R) and fluorine-containing acrylic resins; polysiloxane resins; polyvinyl butyral,
Examples thereof include acetal resins such as polyvinyl acetal and polyvinyl formal; solid waxes such as polyethylene wax and amide wax; fluorine-based and phosphoric acid ester-based surfactants.

As the method for forming the intermediate layer, a solution obtained by dissolving the above materials in a solvent or dispersing them in a latex form is applied by a blade coater, a roll coater, a bar coater, a curtain coater, a gravure coater, etc., and an extrusion lamination by hot melt. The method can be applied, and it can be formed by coating on the cushion layer. Alternatively, there is a method in which a material obtained by dissolving the raw material in a solvent or dispersed in the form of a latex on a temporary base is applied by the above-mentioned method and the cushion layer is bonded and then the temporary base is peeled off.

The thickness of the intermediate layer is preferably 0.1 to 3.0 μm. If the film thickness is too thick, the performance of the cushion layer becomes difficult to appear, so it is necessary to adjust it according to the type of intermediate layer.

A conductive material may be added to the intermediate layer. As the conductive material, for example, acrylic resin,
Uses conductive resin in which vinyl group resin, cellulose resin, etc. has introduced or copolymerized quaternary ammonium salt group, phosphoric acid group, ethosulfate group, vinylpyrrolidone group, sulfonic acid group etc. can do.
Those groups having such an antistatic effect, which are introduced into the resin in a pendant form, can be introduced into the resin at a high density, and thus can have a particularly high antistatic effect, which is preferable. Specific examples thereof include Jurimer series manufactured by Nippon Pure Chemical Co., Ltd., Rheorex series manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., and Elecond series manufactured by Soken Kagaku Co., Ltd.

A material having a π-electron conjugated system structure can be used as the conductive material. Specifically, for example, sulfonated polyaniline, chemically doped polyacetylene, polyparaphenylene vinylene, polyparaphenylene sulfide, chemically polymerized and doped polypyrrole, polythiophene, polyaniline, heat-treated phenol resin produced by heat treatment, Examples include heat-treated products of polyamide and heat-treated products of perylene anhydride. Sulfonated polyaniline is particularly useful as the conductive material having the π-electron conjugated system structure. Various sulfonated polyanilines are known, and one example thereof is sulfonated polyaniline represented by the following chemical formula.

[0095]

[Chemical 1]

In the formula, x, y and n have a molecular weight of about 300.
It is a value of about 10,000. The sulfonated polyaniline is soluble in a solvent containing water or alkaline water,
It forms and dissolves an intramolecular salt or an alkali salt. These sulfonated polyanilines can be used, for example, obtained from Nitto Kagaku Co. under the trade name of aqua Pass-01Z and as an aqueous solution or a solution of a mixed solvent of water and an organic solvent. These solutions are yellowish solutions, but at low concentrations they are almost colorless solutions.

Further, conductive fine particles are used as an antistatic agent.
You can also do it. Examples of such conductive particles include
For example, ZnO, TiO₂, SnO₂, Al₂O₃, In₂O₃,
MgO, BaO, CoO, CuO, Cu₂O, CaO,
SrO, BaO₂, PbO, PbO₂, MnO₃, Mo
O₃, SiO₂, ZrO₂, Ag₂O, Y₂O₃, Bi₂O₃,
Ti₂O₃, Sb₂O₃, Sb₂O_Five, K₂Ti₆O₁₃, NaC
aP₂O₁₈, MgB₂O_FiveOxides such as CuS, ZnS, etc.
Sulfides; SiC, TiC, ZrC, VC, NbC, M
Carbides such as oC and WC; Si₃N_Four, TiN, ZrN, V
N, NbN, Cr₂N and other nitrides; TiB₂, ZrB₂,
NbB₂, TaB₂, CrB, MoB, WB, LaB_Fiveetc
Boride; TiSi₂, ZrSi₂, NbSi₂, TaS
i₂, CrSi₂, MoSi₂, WSi₂And other silicides; Ba
CO₃, CaCO₃, SrCO₃, BaSO _Four, CaSO_Fouretc
Metal salt of SiN_Four-SiC, 9Al₂O₃-2B₂O₃etc
The complex may be mentioned, and one of these may be used alone or two or more may be used.
You may use together. Of these, SnO₂, ZnO,
Al₂O₃, TiO₂, In₂O₃, MgO, BaO and M
oO ₃Is preferred, SnO₂, ZnO, In₂O₃And Ti
O₂Is more preferable, and SnO₂Is particularly preferable.

Other conductive fine particles include carbon black, clay compounds such as bentonite, hectorite, and synthetic hectorite (product name: Laponite manufactured by Nippon Silica Co., Ltd.). Clay minerals facilitate the formation of colloidal dispersions.

Further, various metal particles are used for these conductive fine particles.
On may be doped (contained), for example, with respect to ZnO.
Al, In, etc., TiO, Nb, Ta, etc., S
nO ₂Is doped with Sb, Nb, halogen elements, etc.
You may. Above all, SnO₂And synthetic hectite clay ore
Objects (manufactured by Nippon Silica: Laponite, etc.) are electrically conductive over time
Of SnO₂Is
Sb-doped ones and colloidal dispersion sols are especially
preferable.

When a conductive metal oxide is used as an antistatic agent, the particle size is preferably as small as possible in order to make light scattering as small as possible, but the ratio of the refractive index of the particles to the binder is used as a parameter. It should be determined using and can be determined using Mie's theory. Generally, the average particle size is 0.001 to 0.5
The range is 0.001 to 0.2 μm, and the range is preferably 0.001 to 0.2 μm. The average particle size mentioned here is a value that includes not only the primary particle size of the conductive compound but also the particle size of the higher-order structure.

The amount of the conductive fine particles to be added depends on the types of the resin and the conductive compound when used in a mixture with the resin, but is generally in the range of 10 to 65% by volume with respect to the resin.
15-60% is preferable.

The image-receiving layer for receiving an image of the intermediate transfer medium of the present invention contains at least a binder, and a preferred embodiment is to add a matting agent for use. In addition, various additives may be added as needed. A thermoplastic resin is preferably used as the binder.

Specific examples of the binder used in the image-receiving layer include polyvinyl acetate emulsion adhesives, chloroprene adhesives, epoxy resin adhesives and other adhesives, natural rubbers, chloroprene rubbers, butyl rubbers, and polyacrylics. Adhesive materials such as acid ester type, nitrile rubber type, polysulfide type, silicon rubber type, petroleum type resin, recycled rubber, vinyl chloride type resin, SBR, polybutadiene resin,
Polyisoprene, polyvinyl butyral resin, polyvinyl ether, ionomer resin, SIS, SEBS, acrylic resin, ethylene copolymer, ethylene-vinyl chloride copolymer, ethylene-acrylic copolymer, ethylene-vinyl acetate resin (EVA), vinyl chloride Grafted EVA resin, E
Examples thereof include VA graft vinyl chloride resin, vinyl chloride resin, various modified olefins, polyvinyl butyral, acryl, styrene oligomer, styrene butyl methacrylate, methyl methacrylate, styrene acryl, polyester and urethane. The binder film thickness of the image receiving layer is 0.1
˜2.5 μm is preferred.

The image-receiving layer preferably has projections so as to have appropriate pressure-sensitive adhesiveness to a recording medium, and preferably contains a matting agent, for example. The particle size of the matting agent is preferably about 0.5 to 5 μm larger than the thickness of the image receiving layer, and the addition amount is preferably about 0.1 to 10% by mass.

The outline of the image forming method of the present invention will be described.
An image forming laminate in which the intermediate transfer medium is laminated on the surface of the ink layer of the ink sheet is prepared. The intermediate transfer medium has a support and a cushion layer and an image receiving layer thereon, and is laminated on the surface of the ink layer of the ink sheet so that the image receiving layer is in contact with the surface. When the laser beam is image-wise chronologically irradiated from the support side of the laminate, the laser light irradiation region of the photothermal conversion layer in the ink sheet generates heat, and the adhesive force with the ink layer is reduced, and at the same time, plasticization is performed. The adhesion between the forming layer and the image receiving layer is improved. After that, when the intermediate transfer medium and the ink sheet are peeled off, the laser light irradiation area of the ink layer is transferred onto the image receiving layer of the intermediate transfer medium.

The joining of the ink sheet and the intermediate transfer medium is
It may be performed immediately before the laser light irradiation operation. This laser light irradiation operation usually involves depressurizing the intermediate transfer medium side of the image forming laminate onto the surface of the recording drum (a rotary drum having a vacuum forming mechanism inside and a large number of minute openings on the surface). This is carried out by bringing them into close contact by suction and irradiating laser light from the outside, that is, from the ink sheet side in this state. Irradiation with laser light scans so as to reciprocate in the width direction of the drum, and the drum is rotated at a constant angular velocity during the irradiation operation.

As the laser light used for light irradiation,
Gas laser light such as argon ion laser light, helium neon laser light, helium cadmium laser light, solid-state laser light such as YAG laser light, semiconductor laser light, dye laser light, and direct laser light such as excimer laser light are used. It Further, light obtained by converting these laser lights into a half wavelength through a second harmonic element can also be used.

In the image forming method using the ink sheet and / or the intermediate transfer medium of the present invention, it is preferable to use a semiconductor laser in consideration of output power and easiness of modulation. Further, in the image forming method using the fusion heat transfer method of the present invention, the laser light may be irradiated under the condition that the beam diameter on the photothermal conversion layer is in the range of 5 to 50 μm (particularly 6 to 30 μm). Preferably, scanning speed is 1m
/ Sec or more (particularly 3 m / sec or more) is preferable.

The above-mentioned image forming method is for manufacturing a black mask,
Alternatively, it can be used to form a single-color image, but can also be advantageously used to form a multi-color image.
As a method for forming a multicolor image, for example, a method including the following steps may be mentioned. For example, an ink sheet having ink layers containing pigments having mutually different hues is prepared, and three types of image forming laminates (three colors, for example, cyan, magenta, and yellow) are independently prepared by combining the ink sheet and the intermediate transfer medium. Or 4 types (4 colors, for example, cyan, magenta, yellow, and black) are manufactured. For each stack,
For example, laser light irradiation according to a digital signal based on an image is performed through a color separation filter, the ink sheet and the intermediate transfer medium are subsequently separated, and a color separated image of each color is independently formed on each intermediate transfer medium. Next, the formed color-separated images are sequentially laminated on an actual support such as an actual printing paper prepared separately, or a support similar thereto, so that a multicolor image can be formed.

[0110]

EXAMPLES The present invention is described below with reference to examples, but the embodiments of the present invention are not limited thereto. still,
Unless otherwise specified, “%” in the examples indicates “mass%”.

<Preparation of Ink Sheet Sample 1> Thickness 38 μm
m of transparent PET (polyethylene terephthalate: T-100 manufactured by Diafoil Hoechst) was used as a temporary support, and the following ink layer coating liquid 1 and photothermal conversion layer coating liquid 1 were sequentially applied and dried. Transmission density (OD) of color material layer and light-heat conversion layer
Was measured with a Macbeth TD-904 transmission densitometer.

Yellow: OD = 0.48 (blue filter), dry coating amount: 0.67 g / m ² .

Magenta: OD = 0.68 (green fi
Luther), dry coverage 0.67 g / m ² Dry coverage of photothermal conversion layer is 0.7g / m²Met.

On the other hand, a PET film (T100 manufactured by Mitsubishi Kagaku Polyester Co., Ltd.) having a thickness of 75 μm was coated with the following coating solution 1 for back coat layer at 1.0 g / m ² with a wire bar.
After coating and drying so that the dry coating amount becomes, the following cushion layer coating liquid 1 is coated and dried by a reverse roll coater on the surface opposite to the back coat layer, and the thickness of the cushion layer after drying is 6 μm. Was formed. Then, it was attached to a temporary support, then the temporary support was peeled off, and the color material layer and the photothermal conversion layer were transferred to the side of the support to prepare an ink sheet sample 1. (Backcoat layer coating liquid 1) Polyvinyl alcohol (Gothenol EG-30: manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 41.6% Fluorine compound (Unidyne TG810: manufactured by Daikin Industries, Ltd., resin content 18%) 2.6% Antistatic agent ( F-Coll 214: Matsumoto Yushi Co., Ltd. 5.3% PMMA resin particles (volume average particle size 5.6 μm) 3.2% water 47.3% PMMA: polymethyl methacrylate (cushion layer coating liquid 1) styrene / ethylene / butene Copolymer (Clayton G1657: Shell Japan Co., Ltd.) 14% Tackifier (Super Ester A100: Arakawa Chemical Co., Ltd.) 6% Methyl ethyl ketone 10% Toluene 70% (Photothermal conversion layer coating liquid 1) Polyvinyl alcohol (RS-110: Kuraray Co., Ltd.) 3.6% carbon black aqueous dispersion (CAB-O-JE) 300: CABOT) 2.1% Boric acid 0.24% Fluorosurfactant (FT-251: Neos) 0.06% Water 75.2% i-Propyl alcohol 18.8% <Ink sheet sample 2 Preparation> A 75 μm thick PET film (T100 manufactured by Mitsubishi Kagaku Polyester Co., Ltd.) was coated with the above coating solution 1 for back coat layer using a wire bar.
After applying and drying so that the dry coating amount is 0 g / m ² ,
On the surface opposite to the back coat layer, the following photothermal conversion layer coating liquid 2 is applied by a wire bar and dried to form a photothermal conversion layer having a thickness after drying of 0.2 μm and a wavelength of 808 nm.
A light-heat conversion layer having a transmittance of 1.0 was formed. Next, the following ink layer coating liquid 2 was applied onto the photothermal conversion layer with a wire bar and dried to prepare an ink sheet sample 2. The transmission density of the color material layer was measured with a Macbeth TD-904 transmission densitometer.

[0115]   Yellow: OD = 0.48 (blue filter), dry coverage 0.68 g / m²   Magenta: OD = 0.69 (green filter), dry coverage 0.57 g / m ² (Photothermal conversion layer coating liquid 2)   Polyvinyl butyral (Denka butyral # 3000-4: Denki Kagaku Kogyo Co., Ltd.)   Made) 2.18%   Cross-linking agent (Sumijour N3300: Sumitomo Chemical Co., Ltd.) 0.22%   Infrared absorbing dye (IR-1) 0.6%   Methyl ethyl ketone 67.9%   Cyclohexanone 29.1%

[0116]

[Chemical 2]

On the ink sheet sample 1, ink layer coating liquids 1 to 6, 13 to 14, 18 and 20 having the following compositions were prepared.
Nos. 24 and 31 were applied, and 7 to 12, 15 to 17, 19, 25 and 3 of the following compositions were applied on the ink sheet sample 2.
Ink sheets 1 to 32 were prepared by applying 0 and 32, respectively. (Ink layer coating liquid 1) Pigment dispersion (MHI Yellow # 8099M: Mikuni Chemical Co., 12.0% solution) 27.71% Styrene resin (Haimer ST-95: Sanyo Chemical Co., Ltd.) 7.57% Acrylic resin (Dianal BR-102: manufactured by Mitsubishi Rayon Co., Ltd.) 0.6% Styrene-butadiene copolymer (Kreighton D1101: manufactured by Shell Japan Co.) 0.36% Fluorine-based surfactant (MegaFac F-178K: Dainippon Ink and Chemicals) Company, 30% solution) 0.1% methyl ethyl ketone 1.94% cyclohexanone 61.6% light stabilizer (Sanol 770: Sankyo Co.) 0.12% (ink layer coating solution 2) ink layer coating solution 1 Light stabilizer as antioxidant (Sumilyzer GA-80: Sumitomo Chemical Co., Ltd.)
Changed to. (Ink layer coating liquid 3) The content of the antioxidant in the ink layer coating liquid 2 was changed to 0.6%. (Ink Layer Coating Liquid 4) Pigment Dispersion (MHI Yellow # 8099M: 12.0% Solution, Above) 27.71% Styrene Resin (Haimer ST-95: Above) 7.45% Acrylic Resin (Dianal BR -102: above) 0.6% Styrene / butadiene copolymer (Kraton D1101: above) 0.36% Fluorine-based surfactant (MegaFac F-178K: above, 30% solution) 0.1% Methyl ethyl ketone 1.94% Cyclohexanone 61.6% Light stabilizer (Sanol 770: As mentioned above) 0.12% Antioxidant (Sumilyzer GA-80: As above) 0.12% (Ink layer coating liquid 5) Ink layer Light stabilizer for coating liquid 4,
The content of antioxidant was changed to 0.6% respectively. (Ink Layer Coating Liquid 6) Pigment Dispersion (MHI Yellow # 8099M: 12.0% Solution, Above) 27.71% Styrene Resin (Himmer ST-95: Above) 5.29% Acrylic Resin (Dianal BR -102: above) 0.6% Styrene / butadiene copolymer (Kraton D1101: above) 0.36% Fluorine-based surfactant (MegaFac F-178K: above, 30% solution) 0.1% Methyl ethyl ketone 1.94% Cyclohexanone 61.6% UV absorber (Sumisorb 340: Sumitomo Chemical Co., Ltd.) 2.4% (ink layer coating solution 7) Pigment dispersion (MHI Yellow # 8099M: above, 12.0%) Solution) 34.63% Acrylic copolymer resin (Dianal BR-105: Mitsubishi Rayon Co., Ltd.) 7.1% Fluorine-based surfactant (MegaFac F-178K) 30% solution mentioned above) 0.1% methyl ethyl ketone 0.25% cyclohexanone 57.2% wax (Riquemal HT-10: Riken Vitamin Co., Ltd.) 0.6% light stabilizer (Sanol 770: above). 12% (ink layer coating liquid 8) The content of the light stabilizer in the ink layer coating liquid 7 was changed to 0.6%. (Ink Layer Coating Liquid 9) Pigment Dispersion (MHI Yellow # 8099M: 12.0% Solution, Above) 34.63% Acrylic Copolymer Resin (Dianal BR-105: Above) 6.98% Fluorine-based Interface Activator (Megafac F-178K: above, 30% solution) 0.1% Methyl ethyl ketone 0.25% Cyclohexanone 57.2% Wax (Rikemar HT-10: above) 0.6% Light stabilizer (Sanol) 770: above) 0.12% antioxidant (Sumilyzer GA-80: above) 0.12% (ink layer coating liquid 10) The content of the light stabilizer and the antioxidant of the ink layer coating liquid 9 , Respectively changed to 0.6%. (Ink Layer Coating Liquid 11) Pigment Dispersion (MHI Yellow # 8099M: 12.0% Solution, Above) 34.63% Acrylic Copolymer Resin (Dianal BR-105: Above) 4.82% Fluorine-based Interface Activator (Megafac F-178K: above, 30% solution) 0.1% Methyl ethyl ketone 0.25% Cyclohexanone 57.2% Wax (Riquemar HT-10: above) 0.6% UV absorber (Needral U) -100: manufactured by Taki Chemical Co., Ltd.) 2.4% (ink layer coating liquid 12) The ultraviolet absorber of the ink layer coating liquid 11 is 8% in FX-UFZ-CO (manufactured by Nippon Shokubai Co., Ltd.) and 51.6 in cyclohexanone. Changed to%. (Ink Layer Coating Liquid 13) Pigment Dispersion (MHI Yellow # 5317: Mikuni Dye Co., Ltd., 18.6% solution) 22.96% Styrene resin (Haimer ST-95: supra) 6.62% Acrylic resin (diamond Knall BR-102: supra) 0.6% Styrene-butadiene copolymer (Kraton D1101: supra) 0.36% Fluorosurfactant (Megafac F-178K: supra, 30% solution) 1% Methyl ethyl ketone 7.64% Cyclohexanone 61.6% Light stabilizer (Sanol 770: above) 0.12% (Ink layer coating liquid 14) The light stabilizer of ink layer coating liquid 13 is used as an antioxidant Sumilizer GA. Changed to -80 (previous). (Ink layer coating liquid 15) Pigment dispersion (MHI Yellow # 5317: above, 18.6% solution) 22.96% Acrylic copolymer resin (Dianal BR-105: above) 6.98% Fluorine-based interface Activator (Megafac F-178K: above, 30% solution) 0.1% Methyl ethyl ketone 7.64% Cyclohexanone 61.6% Wax (Rikemar HT-10: above) 0.6% Light stabilizer (Sanol) 770: above) 0.12% (ink layer coating liquid 16) The content of the light stabilizer in the ink layer coating liquid 15 was changed to 0.6%. (Ink layer coating liquid 17) The light stabilizer of the ink layer coating liquid 15 was changed to the antioxidant Sumilizer GA-80 (described above). (Ink Layer Coating Liquid 18) Pigment Dispersion (MHI Yellow # 8099M: 12.0% Solution, Above) 27.71% Styrene Resin (Haimer ST-95: Above) 7.69% Acrylic Resin (Dianal BR -102: above) 0.6% Styrene / butadiene copolymer (Kraton D1101: above) 0.36% Fluorine-based surfactant (MegaFac F-178K: above, 30% solution) 0.1% Methyl ethyl ketone 1.94% Cyclohexanone 61.6% (ink layer coating liquid 19) Pigment dispersion (MHI Yellow # 8099M: 12.0% solution described above) 34.63% Acrylic copolymer resin (Dianal BR-105: (Above) 7.21% Fluorine-based surfactant (Megafac F-178K: above, 30% solution) 0.1% Methyl ethyl ketone 0.25% Cyclo Xanone 57.2% Wax (Rikemar HT-10: as described above) 0.6% (ink layer coating liquid 20) Pigment dispersion (MHI Magenta # 8100M: Mikuni pigment company, 19.5% solution) 20.78% Styrene resin (Heimer ST-95: above) 6.84% Acrylic resin (Dianal BR-102: above) 0.6% Styrene-butadiene copolymer (Kraton D1101: above) 0.36% Fluorine-based Surfactant (Megafac F-178K: above, 30% solution) 0.1% Methyl ethyl ketone 9.6% Cyclohexanone 61.6% Light stabilizer (Sanol 770: above) 0.12% (ink layer coating) Liquid 21) The light stabilizer of the ink layer coating liquid 20 was changed to the antioxidant Sumilizer GA-80 (supra). (Ink layer coating liquid 22) The content of the antioxidant in the ink layer coating liquid 21 was changed to 0.6%. (Ink Layer Coating Liquid 23) Pigment Dispersion (MHI Magenta # 8100M: Above, 19.5% Solution) 20.78% Styrene Resin (Haimer ST-95: Above) 6.72% Acrylic Resin (Dianal BR -102: above) 0.6% Styrene / butadiene copolymer (Kraton D1101: above) 0.36% Fluorine-based surfactant (MegaFac F-178K: above, 30% solution) 0.1% Methyl ethyl ketone 9.6% Cyclohexanone 61.6% Light stabilizer (Sanol 770: supra) 0.12% Antioxidant (SUMILIZER GA-80: supra) 0.12% (ink layer coating liquid 24) Pigment dispersion Material (MHI Magenta # 8100M: 19.5% solution as described above) 20.78% Styrene resin (Heimer ST-95: as described above) 4.56% Acrylic resin (die Knall BR-102: supra) 0.6% Styrene-butadiene copolymer (Kraton D1101: supra) 0.36% Fluorosurfactant (Megafac F-178K: supra, 30% solution) 1% Methyl ethyl ketone 4% Cyclohexanone 61.6 UV absorber (FX-UFZ-CO: above) 8% (ink layer coating solution 25) Pigment dispersion (MHI Magenta # 8100M: above, solid content 19.5%) 22.87% Acrylic copolymer resin (Dianal BR-105: above) 6.19% Fluorine-based surfactant (MegaFac F-178K: above, 30% solution) 0.1% Methyl ethyl ketone 7.92% Cyclohexanone 61.6% Wax 1 (Rikemar HT-10: described above) 0.6% Wax 2 (Rikestar EW-90: Riken Vitamin Co.) 0 6% light stabilizer: changed (Sanol 770 supra) to 0.12% (Ink layer coating solution 26) light stabilizers antioxidants of the ink layer coating solution 25 Sumilizer GA-80 (supra). (Ink Layer Coating Liquid 27) Pigment Dispersion (MHI Magenta # 8100M: Above, 19.5% Solution) 22.87% Acrylic Copolymer Resin (Dianal BR-105: Above) 6.07% Fluorine-based Interface Activator (Megafac F-178K: above, 30% solution) 0.1% Methyl ethyl ketone 7.92% Cyclohexanone 61.6% Wax 1 (Rikemar HT-10: above) 0.6% Wax 2 (Likestar EW -90: above) 0.6% light stabilizer (Sanol 770: above) 0.12% antioxidant (Sumilyzer GA-80: above) 0.12% (ink layer coating liquid 28) ink layer The contents of the light stabilizer and the antioxidant of the coating liquid 27 were changed to 0.6% respectively. (Ink layer coating liquid 29) Pigment dispersion (MHI Magenta # 8100M: above, 19.5% solution) 22.87% Acrylic copolymer resin (Dynar BR-105: above) 3.91% Fluorine-based interface Activator (Megafac F-178K: above, 30% solution) 0.1% Methyl ethyl ketone 7.92% Cyclohexanone 61.6% Wax 1 (Rikemar HT-10: above) 0.6% Wax 2 (Likestar EW -90: above) 0.6% UV absorber (Sumisorb 340: above) 2.4% (ink layer coating liquid 30) The UV absorber of ink layer coating liquid 29 is FX-UFZ-CO (previous). 8% and methyl ethyl ketone was changed to 2.32%. (Ink Layer Coating Liquid 31) Pigment Dispersion (MHI Magenta # 8100M: Above, 19.5% Solution) 20.78% Styrene Resin (Haimer ST-95: Above) 6.96% Acrylic Resin (Dianal BR -102: above) 0.6% Styrene / butadiene copolymer (Kraton D1101: above) 0.36% Fluorine-based surfactant (MegaFac F-178K: above, 30% solution) 0.1% Methyl ethyl ketone 9.6% Cyclohexanone 61.6% (Ink layer coating liquid 32) Pigment dispersion (MHI Magenta # 8100M: above, 19.5% solution) 22.87% Acrylic copolymer resin (Dianal BR-105: (Previously mentioned) 6.31% Fluorine-based surfactant (Megafac F-178K: above, 30% solution) 0.1% Methyl ethyl ketone 7.92% Shik Hexanone 61.6% Wax 1 (Rikemar HT-10: supra) 0.6% Wax 2 (Rikestar EW-90: supra) 0.6% <Preparation of intermediate transfer medium> White PET film with a thickness of 100 μm ( UL9: manufactured by Teijin Limited), the following BC layer coating solution was applied and dried with a wire bar to a dry coating amount of 2.5 g / m ² , and the following was applied to the surface opposite to the back coat layer. The cushion layer coating liquid 1 was applied and dried by an applicator so that the film thickness after drying would be 20 μm to form a cushion layer. Then, on the cushion layer,
The following intermediate layer coating liquid 1 was applied to a wire bar at 3.4 g / m 2.
Apply and dry to a dry coating amount of ² , and then apply the following image-receiving layer coating liquids 1 and 14 on the release layer with a wire bar to a dry coating amount of 1.5 g / m ^2.・
The intermediate transfer media 1 and 14 were manufactured by drying. The obtained intermediate transfer medium was wound around a paper tube having an outer diameter of 7.6 cm such that the surface of the image receiving layer was wound outside.

Similarly, the following intermediate layer coating liquid 2 was applied onto the cushion layer with a wire bar so as to have a dry coating amount of 1.0 g / m ² , and dried on the release layer. The following image-receiving layer coating liquids 2 to 13 were applied and dried with a wire bar to a dry coating amount of 1.5 g / m ² , and intermediate transfer media 2 to 13 were produced. The obtained intermediate transfer medium was wound around a paper tube having an outer diameter of 7.6 cm such that the surface of the image receiving layer was wound outside. (BC layer coating liquid) Polyester resin (Vylon 200: manufactured by Toyobo Co., Ltd.) 9.0% PMMA resin particles (MX-1000: manufactured by Soken Chemical Industry Co., Ltd.) 0.3% 18% MEK dispersion of carbon black (MHI black # 273: Mikuni Dye Co., Ltd.) 3.6% Silicon oil (X-24-8300: Shin-Etsu Chemical Co., Ltd.) 2% Propylene glycol monomethyl ether acetate 40% Toluene 20% Methyl ethyl ketone 27.1% (Cushion layer coating liquid 1) Polyethylene Latex (S3127: Toho Chemical Co., resin content 35%) 100% (Intermediate layer coating solution 1) Ethyl cellulose (Ethocel 10: Dow Chemical Co., Ltd.) 13% Ethyl alcohol 87% (Intermediate layer coating solution 2) Polyethylene latex ( S3127: 35% resin content above) 4.2% ceramace -8 (manufactured by Taki Chemical Co., Ltd.) 33.3% 10% aqueous dispersion of PMMA resin particles (MX220: manufactured by Soken Chemical Co., Ltd.) 7.5% Fluorine-based surfactant (FT-251: supra) 0.5 % Water 35.5% i-Propanol 19% (Image-receiving layer coating solution 1) Acrylic resin latex (Iodosol A5805: manufactured by Nippon NSC, resin content 55%) 25% PMMA resin particle 30% aqueous dispersion (MX-40S) : Soken Chemical Co., Ltd.) 1.8% Fluorine compound (Unidyne TG810: Daikin Industries, Ltd., resin content 18%) 4.2% i-Propyl alcohol 6% Water 60% (Image-receiving layer coating liquid 2) Acrylic resin (Diamond) Knall BR-102: 20% MEK solution of the above) 49.8% Tospearl T-130 (manufactured by Toshiba Silicone Co., Ltd.) 10% MEK dispersion 0.3% Methyl ethyl ketone 50.2 Cyclohexanone 18% (Image-receiving layer coating liquid 3) 20% MEK solution of acrylic resin (Dianal BR-102: supra) 49.8% Tospearl T-130 (previous) 10% MEK dispersion 0.3% Antioxidant (Sumilyzer GA-80: As mentioned above) 0.1% Methyl ethyl ketone 32.2% Cyclohexanone 18% (Image-receiving layer coating liquid 4) 20% MEK solution of acrylic resin (Dynar BR-102: As mentioned above) 39 10% MEK dispersion liquid of 3% Tospearl T-130 (explained above) 0.3% Antioxidant (Sumilyzer GA-80: Explained above) 0.1% UV absorber (Sumisorb 350: Sumitomo Chemical Co., Ltd.) 2 0.0% Methyl ethyl ketone 40.2% Cyclohexanone 18% (Image-receiving layer coating liquid 5) Acrylic resin (Dianal BR-102: 20) MEK solution 39.8% Tospearl T-130 (supra) 10% MEK dispersion 0.3% UV absorber (Sumisorb 340: supra) 2.0% Methyl ethyl ketone 39.8% Cyclohexanone 18% (image receiving layer Coating Liquid 6) The ultraviolet absorber of the coating liquid 5 for the image receiving layer was changed from Sumisorb 340 to Sumisorb 350 (described above). (Image-receiving layer coating liquid 7) 20% MEK solution of acrylic resin (Dianal BR-102: mentioned above) 34.8% 10% MEK dispersion of Tospearl T-130 (mentioned above) 0.3% UV absorber (Sumisorb 340: described above) 3.0% Methyl ethyl ketone 43.8% Cyclohexanone 18% (Image-receiving layer coating liquid 8) The ultraviolet absorber of the image-receiving layer coating liquid 5 was changed from Smithsorb 340 to Nidral U-100 (described above). . (Image-Receiving Layer Coating Liquid 9) The ultraviolet absorber of the image-receiving layer coating liquid 5 was changed from Smithsorb 340 to FX-UFZ-CO (described above). (Image-Receiving Layer Coating Liquid 10) The antioxidant of the image-receiving layer coating liquid 4 was changed to Sanol 770 (described above) which is a light stabilizer, and the ultraviolet absorber was changed to Sumisorb 350 (described above). (Image-receiving layer coating solution 11) 20% MEK solution of acrylic resin (Dianal BR-102: described above) 47.3% Tospearl T-130 (described above) 10% MEK dispersion solution 0.3% Light stabilization Agent (Sanol 770: described above) 0.5% Methyl ethyl ketone 33.8% Cyclohexanone 18% (Image-receiving layer coating solution 12) The antioxidant of the image-receiving layer coating solution 3 is converted to the light stabilizer Sanol 765 (manufactured by Sankyosha). changed. (Image-Receiving Layer Coating Liquid 13) The antioxidant of the image-receiving layer coating liquid 3 was changed to Sanol 2626 (manufactured by Sankyo Co.). (Image-receiving layer coating liquid 14) Acrylic resin latex (Iodosol A5805: resin content 55% above) 13.6% 30% aqueous dispersion of PMMA resin particles (MX-40S: manufactured by Soken Chemical Co., Ltd.) 0.66% Fluorine Compound (Unidyne TG810: as described above, resin content 18%) 3.3% UV absorber (10% aqueous dispersion of Nedral W-10: manufactured by Taki Chemical Co., Ltd.) 20% i-propyl alcohol 9% water 53.4 % <Image formation and evaluation> Exposure machine is Color Dec
The ink sheet and the intermediate transfer medium are brought into close contact with each other under reduced pressure by using IsionII (manufactured by Konica), and after solid printing of each color (Y, M) is recorded with an exposure energy of 220 mJ / cm ² , the ink sheet and the intermediate transfer medium are peeled off. , E on the image of the intermediate transfer medium
Using V-Laser-laminator TP400 (manufactured by Konica), an image was laminated on NK high coat (manufactured by Nippon Kako Kaisha) to form a final image.

With respect to the final image (yellow, magenta), the following light resistance and dark fading resistance were evaluated. The results are shown in Table 1 and Table 2, respectively.

<< Lightfastness (Bright room storage) >> Each of the obtained prints was exposed under a light source of 8000 LUX for 1 week, and the L ^* a ^* b ^* values before and after irradiation were measured by D196 (manufactured by Gretag).
The change in ΔE before and after the light irradiation was calculated and evaluated in four levels.

⊚: ΔE <0.5 ○: 0.5 ≦ ΔE <1.0 Δ: 1.0 ≦ ΔE <2.0 ×: 2.0 ≦ ΔE << Dark fading (durability in the dark) >> When the transferred image obtained in the same manner was stored in a thermostat at 55 ° C. for 1 week, Δ before and after storage
The variation of E was calculated and evaluated in 3 levels.

[0122] ◯: ΔE <0.5 Δ: 0.5 ≦ ΔE <1.0 X: 1.0 ≦ ΔE <2.0

[0123]

[Table 1]

[0124]

[Table 2]

It was confirmed that the combination of both yellow and magenta according to the present invention improves the storability in a bright room and the storability in a dark place.

Samples were similarly prepared for cyan and black, and the storage stability was confirmed. As a result, both the storage stability in the bright room and the storage stability in the dark were improved.

The intermediate transfer medium in which an ultraviolet absorber, an antioxidant and a light stabilizer were added to the image receiving layer of the intermediate transfer medium had good transferability to paper.

[0128]

According to the present invention, it is possible to improve the light resistance of the printed matter output by the DDCP and to extremely reduce the color fluctuation even during long-term storage.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B41M 5/26 HF term (reference) 2C068 AA06 BB19 BC13 BC24 2H111 AA04 AA09 AA12 AA26 AB05 BA03 BA04 BA55 BA76 CA03 CA33 CA37

Claims (5)

[Claims] 1. An ink sheet, wherein the ink layer of the ink sheet used in the laser melting thermal transfer system contains at least one of an ultraviolet absorber, an antioxidant and a light stabilizer. 2. The ink sheet according to claim 1, wherein the ink sheet has at least a photothermal conversion layer and an ink layer containing a pigment. 3. An image receiving layer of an intermediate transfer medium used in a laser melting thermal transfer system in which an image is recorded with a laser and then retransferred to a final image carrier, and at least one of an ultraviolet absorber, an antioxidant and a light stabilizer is used. An intermediate transfer medium containing one of: 4. An image forming method by a laser fusion thermal transfer system, which comprises using one of the ink sheet according to claim 1 and the intermediate transfer medium according to claim 3. 5. An image forming method by a laser fusion thermal transfer method, wherein the ink sheet according to claim 1 and the intermediate transfer medium according to claim 3 are used in combination.