JP7028007B2 - Intermediate transfer medium - Google Patents

Description

The present invention relates to an intermediate transfer medium.

Conventionally, various thermal transfer recording methods have been known, but in recent years, a thermal transfer sheet having a dye layer containing a sublimation dye and a transfer subject are superposed, and then a thermal transfer sheet is provided by a thermal head provided in a thermal transfer printer. A sublimation-type thermal transfer method is widely used in which the sublimable dye in the dye layer is transferred onto the transferred object to form an image by heating.

Image formation by the sublimation type thermal transfer method may be difficult depending on the surface shape of the transferred object, and in such a case, image formation using an intermediate transfer medium provided with a transfer layer is performed. ..
To form an image using an intermediate transfer medium, the thermal transfer sheet is heated and the sublimation dye in the dye layer included in the thermal transfer sheet is transferred to the receiving layer constituting the transfer layer included in the intermediate transfer medium to form an image. After that, the intermediate transfer medium is heated to transfer the transfer layer onto the transfer object. Further, such an intermediate transfer medium further includes a protective layer as a layer constituting the transfer layer for the purpose of improving the durability of the formed image.

Such an intermediate transfer medium is required to have high transferability in which an untransferred portion is not generated at the time of transfer of the transfer layer. For example, by reducing the molecular weight of the resin material contained in the protective layer. It is possible to improve the transferability.

However, due to the low molecular weight of the resin material contained in the protective layer, the sublimable dye may not stay in the transfer layer but reach the non-transfer layer such as the substrate when the image is formed on the receiving layer. there were. Therefore, there is a possibility that the content of the formed image can be grasped from the intermediate transfer medium after the transfer, which causes a problem from the viewpoint of preventing information leakage.

The present invention has been made in view of the above problems, and the problem to be solved is intermediate transfer having high information leakage prevention property even when the resin material contained in the protective layer has a low molecular weight. To provide a medium.

The intermediate transfer medium of the present invention in the first aspect includes a non-transfer layer including a base material and a release layer, and a transfer layer including a protective layer and a receiving layer, and the release layer is a coloring material and a urethane resin. The OD value of the non-transfer layer is 0.2 or more.

In the above aspect, the content of the coloring material in the release layer is preferably 5% by mass or more and 70% by mass or less.

In the above aspect, the content of the urethane resin in the release layer is preferably 5% by mass or more and less than 75% by mass.

In the above embodiment, the thickness of the release layer is preferably 0.15 μm or more and 20 μm or less.

In the above embodiment, the non-transfer layer preferably includes a primer layer between the base material and the release layer.

In the above embodiment, the primer layer preferably contains a urethane resin.

In the above embodiment, the protective layer preferably contains a resin material having a number average molecular weight of 1500 or more and 18000 or less.

The intermediate transfer medium of the present invention in the second aspect includes a non-transfer layer including a base material, a primer layer and a release layer, and a transfer layer including a protective layer and a receiving layer, and the primer layer comprises a coloring material. The release layer contains a urethane resin, and the OD value of the non-transfer layer is 0.2 or more.

In the above embodiment, the content of the coloring material in the primer layer is preferably 10% by mass or more and 70% by mass or less.

In the above embodiment, the thickness of the primer layer is preferably 0.05 μm or more and 20 μm or less.

In the above aspect, the content of the urethane resin in the release layer is preferably 5% by mass or more and 75% by mass or less.

In the above embodiment, the primer layer preferably contains a urethane resin.

In the above embodiment, the protective layer preferably contains a resin material having a number average molecular weight of 1500 or more and 18000 or less.

According to the present invention, it is possible to provide an intermediate transfer medium having a high information leakage prevention property even when the resin material contained in the protective layer has a low molecular weight.

It is a schematic cross-sectional view which shows the intermediate transfer medium of this invention in 1st Embodiment. It is a schematic cross-sectional view which shows the intermediate transfer medium of this invention in 1st Embodiment. It is a schematic cross-sectional view which shows the intermediate transfer medium of this invention in 1st Embodiment. FIG. 3 is a schematic cross-sectional view showing the intermediate transfer medium of the present invention in the second aspect. FIG. 3 is a schematic cross-sectional view showing the intermediate transfer medium of the present invention in the second aspect.

(Intermediate transfer medium of the first aspect)
In the first aspect, as shown in FIG. 1, the intermediate transfer medium 10 of the present invention comprises a non-transfer layer 13 including a release layer 12 including a base material 11 and a coloring material, a protective layer 14 and a receiving layer 15. The transfer layer 16 is provided.
Further, in one embodiment, the transfer layer 16 included in the intermediate transfer medium 10 of the present invention further includes a release layer 17 as shown in FIG.
Further, in one embodiment, as shown in FIG. 3, the non-transfer layer 13 included in the intermediate transfer medium 10 of the present invention includes a primer layer 18 between the base material 11 and the release layer 12.
Hereinafter, each layer included in the thermal transfer image receiving sheet of the present invention will be described.

(Non-transfer layer)
In the first aspect, the non-transfer layer comprises at least a substrate and a release layer. Further, in one embodiment, the non-transfer layer includes a primer layer between the base material and the release layer.

The optical density (OD value) of the non-transfer layer is 0.2 or more, more preferably 0.5 or more, and further preferably 1 or more. This makes it possible to improve the information leakage prevention property of the intermediate transfer medium.
In the present invention, the OD value of the non-transfer layer refers to the OD value of the non-transfer layer after the transfer layer is transferred from the intermediate transfer medium of the present invention onto the transfer target, and is a Macbeth transmission densitometer (Macbeth). It is measured using TR-924) manufactured by the company.

(Base material)
The base material has heat resistance that can withstand the thermal energy applied during thermal transfer (for example, heat from a thermal head), and has mechanical strength that can support a receiving layer or the like provided on the base material.
Examples of the base material include paper base materials such as high-quality paper, art paper, coated paper, resin-coated paper, cast-coated paper, paperboard, synthetic paper and impregnated paper, polyethylene terephthalate (PET), polyvinyl terephthalate (PBT), and polyethylene. Naphthalate (PEN), 1,4-polycyclohexylene methylene terephthalate, ester resin such as terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer, amide resin such as nylon 6 and nylon 6,6, polyethylene (PE) , Polyethylene (PP) and polyolefins such as polymethylpentene, polyvinyl chloride, polyvinyl alcohol (PVA), polyvinyl acetate, vinyl chloride-vinyl acetate copolymer and vinyl resins such as polyvinylpyrrolidone (PVP), polyvinylacetacetal and Vinyl acetal resin such as polyvinyl butyral, (meth) acrylic resin such as polyacrylate, polymethacrylate and polymethylmethacrylate, imide resin such as polyimide and polyetherimide, cellophane, cellulose acetate, nitrocellulose, cellulose acetate propionate. A film composed of a cellulose resin such as (CAP) and cellulose acetate butyrate (CAB), polystyrene (PS), a carbonate resin, an ionomer resin and the like (hereinafter, simply referred to as "resin film") can be used. The resin film may be a stretched film or an unstretched film, but from the viewpoint of strength, it is preferable to use a stretched film stretched in the uniaxial direction or the biaxial direction.
In the present invention, "(meth) acrylic" includes both "acrylic" and "methacrylic".
Further, in the present invention, "(meth) acrylate" includes both "acrylate" and "methacrylate".

Further, the above-mentioned laminated body made of a paper base material alone, a laminated body made of a resin film alone, or a laminated body made of a paper base material and a resin film can be used as a base material.
These laminates can be produced by using a dry lamination method, a wet lamination method, an extraction method, or the like.

The thickness of the base material is not particularly limited, and may be, for example, 1 μm or more and 300 μm or less.

(Release layer)
In the first aspect, the release layer contains a colorant and a urethane resin. By containing the colorant and the urethane resin in the release layer, the information leakage prevention property of the intermediate transfer medium can be improved, and the adhesion to the base material can be improved.

The coloring material contained in the release layer may be a pigment or a dye. The color of the coloring material is not particularly limited, but is preferably one having the same hue as the image formed on the receiving layer. This makes it possible to improve the information leakage prevention property of the intermediate transfer medium.

Examples of the coloring material include carbon black, graphite, titanium white, zinc flower, cobalt blue titanium yellow, isoindolinone yellow, Hansa yellow A, quinacridon red, permanent red 4R, phthalocyanine blue, induthren blue RS, and aniline black. Examples thereof include metal pigments made of metal powders such as aluminum and brass. Among these, carbon black is preferable from the viewpoint of preventing information leakage. The release layer may contain two or more of the above coloring materials.

In one embodiment, the content of the coloring material in the release layer is preferably 5% by mass or more and 70% by mass or less, more preferably 10% by mass or more and 69% by mass or less, and 15% by mass or more and 68% by mass. It is more preferably 5% by mass or less, and particularly preferably 25% by mass or more and 65% by mass or less. This makes it possible to improve the information leakage prevention property of the intermediate transfer medium. In addition, it is possible to prevent color transfer to the protective layer and the peeling layer provided in the transfer layer.

The urethane resin contained in the release layer may be a two-component curable urethane resin or a one-component curable urethane resin.
The two-component curable urethane resin is a reaction product of a polyol and an isocyanate compound.
Examples of the polyol have two or more hydroxyl groups in the molecule, and examples thereof include polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol, polyether polyol, polycarbonate polyol, and polyurethane polyol.
Further, as the isocyanate compound, a polyvalent isocyanate having two or more isocyanate groups in the molecule is used, for example, 2,4-toluene diisocyanate, xylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,6--. Examples thereof include hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate and hydrogenated diphenylmethane diisocyanate. The release layer can contain two or more types of the urethane resin.

In the first aspect, the content of the urethane resin in the release layer is preferably 5% by mass, 75% by mass or less, more preferably 10% by mass or more and 65% by mass or less, and 15% by mass or more. , 50% by mass or less, more preferably. As a result, it is possible to prevent color transfer to the protective layer and the peeling layer provided in the transfer layer while maintaining the adhesion of the release layer to the base material.

In one embodiment, the release layer can contain a resin material other than the urethane resin, for example, a (meth) acrylic resin, an ester resin, a cellulose resin, a styrene resin such as polystyrene and acrylonitrile styrene, an amide resin, a polyvinyl acet. Includes vinyl acetal resins such as acetal and polyvinyl butyral, and resin materials such as carbonate resins. Among these, it is preferable to contain a vinyl acetal resin because the adhesion between layers can be adjusted. The release layer can contain two or more of the above resin materials.

The release layer includes a plastic material, a filler, an ultraviolet stabilizing material, a surfactant, a fluorescent whitening material, a matte material, a deodorant material, a flame-retardant material, and a weatherproof material, as long as the characteristics of the present invention are not impaired. Additives such as antistatic materials, thread friction reducing materials, slip materials, antioxidant materials, ion exchange materials, dispersants and ultraviolet absorbers can be included.

In one embodiment, the release layer is printed with an arbitrary pattern. This makes it possible to further improve the information leakage prevention property of the intermediate transfer medium. The pattern is not particularly limited, and is composed of a plurality of lines, a plurality of patterns arranged at regular intervals or random intervals, and arbitrary characters arranged at regular intervals or random intervals. And so on.

The thickness of the release layer is preferably 0.15 μm or more and 20 μm or less, more preferably 0.5 μm or more and 15 μm or less, and particularly preferably 0.8 μm or more and 10 μm or less. This can improve the information leakage prevention property of the intermediate transfer medium.

The release layer is prepared by dispersing or dissolving the above-mentioned material in water or an appropriate solvent to obtain a coating liquid, which is used as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method and the like. It can be formed by applying it on a substrate by a known means such as a rod coating method to form a coating film, and drying the coating film.

(Primer layer)
In one embodiment, the primer layer is a urethane resin, a (meth) acrylic resin, an ester resin, a cellulose resin, a styrene resin such as polystyrene and acrylonitrile styrene, an amide resin, a vinyl acetal resin such as polyvinyl acetatetal and polyvinyl butyral, and a carbonate resin. Including resin materials such as. Among these, urethane resin is preferably contained because the adhesion between the base material and the release layer can be further improved. The primer layer can contain two or more of the above resin materials.

In the first aspect, the content of the resin material in the primer layer is not particularly limited, but can be, for example, 50% by mass or more and 99% by mass or less.

The primer layer may contain the above-mentioned additive as long as the characteristics of the present invention are not impaired.

In one embodiment, the primer layer is printed with an arbitrary pattern. This makes it possible to further improve the information leakage prevention property of the intermediate transfer medium. Specific examples of the pattern are as described above.

The thickness of the primer layer is not particularly limited, but can be, for example, 0.5 μm or more and 10 μm or less.

In the primer layer, the above material is dispersed or dissolved in water or an appropriate solvent to obtain a coating liquid, which is used as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method and a rod. It can be formed by applying it on a substrate by a known means such as a coating method to form a coating film, and drying the coating film.

(Transfer layer)
In the first aspect, the transfer layer comprises at least a protective layer and a receiving layer. Further, in one embodiment, the transfer layer further includes a release layer under the protective layer.

(Protective layer)
In one embodiment, the protective layer contains resin materials such as (meth) acrylic resin, ester resin, cellulose resin, styrene resin, amide resin, vinyl acetal resin, carbonate resin, thermosetting resin and active photocurable resin. Among these, ester resin is preferable from the viewpoint of durability of the printed matter. The protective layer may contain two or more of the above resin materials.

The number average molecular weight (Mn) of the resin material is preferably 1500 or more and 18,000 or less, and more preferably 1500 or more and 15,000 or less. By setting the Mn of the resin material within the above numerical range, the transferability of the transfer layer can be improved. A resin material having Mn of about 20,000 or 30,000 can also be used.
In the present invention, Mn is a value obtained in terms of polystyrene by gel permeation chromatography (GPC) in accordance with JIS K 7252-1 (2008).

The protective layer may contain the above-mentioned additives as long as the characteristics of the present invention are not impaired.

The thickness of the protective layer is preferably 0.1 μm or more and 50 μm or less, more preferably 0.5 μm or more and 20 μm or less, and particularly preferably 1 μm or more and 10 μm or less. By setting the thickness of the protective layer within the above numerical range, the durability of the protective layer can be improved and the transferability of the transfer layer can be improved.

The protective layer is obtained by dispersing or dissolving the above-mentioned material in water or an appropriate solvent to obtain a coating liquid, which is used as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method and a rod. It can be formed by applying it on a release layer or a release layer by a known means such as a coating method to form a coating film, and drying the coating film.

(Receptive layer)
The receiving layer is a layer that receives the sublimation dye transferred from the dye layer included in the thermal transfer sheet and maintains the formed image.

The receiving layer contains a resin material, for example, polyolefins such as PE and PP, polyvinyl chloride, polyvinyl alcohol (PVA), polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral and PVP, ethylene-vinyl acetate. Vinyl resin such as copolymer, (meth) acrylic resin, cellophane, cellulose acetate, nitrocellulose, cellulose resin such as CAP and CAB, PET, PBT, PEN, 1,4-polycyclohexylene methylene terephthalate, polyethylene terephthalate- Examples thereof include ester resins such as isophthalate copolymers and terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymers, amide resins such as nylon 6 and nylons 6 and 6, carbonate resins, styrene resins, and urethane resins. The receiving layer can contain two or more of the above resin materials.

In one embodiment, the receiving layer comprises a silicone oil. Since the receiving layer contains silicone oil, the releasability between the thermal transfer sheet and the receiving layer at the time of image formation can be improved.

Examples of the silicone oil include straight silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, amino-modified silicone oil, epoxy-modified silicone oil, carboxy-modified silicone oil, methacryl-modified silicone oil, mercapto-modified silicone oil, and carbinol-modified. Examples thereof include modified silicone oils such as silicone oil, fluorine-modified silicone oil, methylstyryl-modified silicone oil, and polyether-modified silicone oil.
Among the above, modified silicone oil is preferable because it can further improve the releasability of the receiving layer. Modified silicone oils include single-ended, double-ended, side-chain single-ended and side-chain double-ended modified silicone oils. The receiving layer may contain two or more of the above silicone oils.

The content of the silicone oil in the receiving layer is preferably 0.1% by mass or more and 10% by mass or less, and more preferably 1% by mass or more and 5% by mass or less. By setting the content of the silicone oil in the receiving layer within the above numerical range, the releasability between the thermal transfer sheet and the receiving layer at the time of image formation can be further improved.

The receiving layer may contain the above-mentioned additive as long as the characteristics of the present invention are not impaired.

The thickness of the receiving layer is preferably 0.5 μm or more and 20 μm or less, and more preferably 1 μm or more and 10 μm or less. By setting the thickness of the receiving layer within the above numerical range, the dye acceptability of the receiving layer can be improved.

The receiving layer disperses or dissolves the above-mentioned material in water or an appropriate solvent to prepare a coating liquid, which is used as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method and a rod. It can be formed by applying it on a protective layer by a known means such as a coating method to form a coating film, and drying the coating film.

(Release layer)
In one embodiment, the transfer layer included in the intermediate transfer medium of the present invention includes a release layer under the protective layer. Thereby, the transferability of the transfer layer can be improved.

In one embodiment, the release layer contains a resin material, and examples thereof include (meth) acrylic resin, cellulose resin, vinyl resin, urethane resin, silicone resin, and fluororesin.

In one embodiment, the release layer comprises wax, for example, natural waxes such as beeswax, whale wax, wood wax, rice bran wax, carnauba wax, candelilla wax and montan wax, paraffin wax, microcrystallin wax, oxide wax, ozokelite. , Selecin, synthetic waxes such as ester wax and polyethylene wax, higher saturated fatty acids such as margaric acid, lauric acid, myristic acid, palmitic acid, stearic acid, floic acid and behenic acid, and higher saturated monovalent alcohols such as stearyl alcohol and behenyl alcohol. , Higher esters such as sorbitan fatty acid esters, higher fatty acid amides such as stearate amides and oleic acid amides, and the like.
The release layer may be a silicone resin, a silicone-modified resin, a fluororesin, a fluorine-modified resin, a vinyl resin such as polyvinyl alcohol, a (meth) acrylic resin, a heat-crosslinkable epoxy-amino resin, a heat-crosslinkable alkyd-amino resin, or the like. Can include. The release layer may contain two or more of the above-mentioned materials.

The release layer may contain the above-mentioned additive as long as the characteristics of the present invention are not impaired.

The thickness of the release layer is preferably 0.1 μm or more and 5.0 μm or less, and more preferably 0.2 μm or more and 2.0 μm or less. By setting the thickness of the release layer within the above numerical range, the transferability of the transfer layer can be improved.

The peeling layer is formed by dispersing or dissolving the above-mentioned material in water or an appropriate solvent, and known as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method, a rod coating method and the like. By means, it can be formed by applying it on the release layer to form a coating film and drying it.

(Intermediate transfer medium of the second aspect)
In the second aspect, as shown in FIG. 4, the intermediate transfer medium 20 of the present invention includes a base material 21, a non-transfer layer 24 including a primer layer 22 containing a coloring material, and a release layer 23, a protective layer 25, and a protective layer 25. A transfer layer 27 including a receiving layer 26 is provided.
In the intermediate transfer medium according to the second aspect, since the layer containing the coloring material and the transfer layer are not adjacent to each other, a good printed matter can be produced without causing color transfer to the transfer layer.

Further, in one embodiment, the transfer layer 27 included in the intermediate transfer medium 20 of the present invention further includes a release layer 28 as shown in FIG.
Hereinafter, each layer included in the thermal transfer image receiving sheet of the present invention will be described.

(Non-transfer layer)
In the second aspect, the non-transfer layer comprises a substrate, a primer layer and a release layer.

The OD value of the non-transfer layer is 0.2 or more, more preferably 0.5 or more, and further preferably 1 or more. This makes it possible to improve the information leakage prevention property of the intermediate transfer medium.

(Base material)
Since the materials and thicknesses constituting the base material are the same as those in the first aspect, the description thereof will be omitted here.

(Primer layer)
In the second aspect, the primer layer contains a colorant. The coloring material contained in the primer layer may be a pigment or a dye. The color of the coloring material is not particularly limited, but is preferably one having the same hue as the image formed on the receiving layer. This makes it possible to improve the information leakage prevention property of the intermediate transfer medium.

Examples of the coloring material include carbon black, graphite, titanium white, zinc flower, cobalt blue titanium yellow, isoindolinone yellow, Hansa yellow A, quinacridon red, permanent red 4R, phthalocyanine blue, induthren blue RS, and aniline black. Examples thereof include metal pigments made of metal powders such as aluminum and brass. The primer layer may contain two or more of the above coloring materials.

The content of the coloring material in the primer layer is preferably 10% by mass or more and 70% by mass or less, more preferably 15% by mass or more and 68% by mass or less, and 25% by mass or more and 65% by mass or less. Is more preferable. This makes it possible to improve the information leakage prevention property of the intermediate transfer medium.

In one embodiment, the primer layer is a urethane resin, a (meth) acrylic resin, an ester resin, a cellulose resin, a styrene resin such as polystyrene and acrylonitrile styrene, an amide resin, a vinyl acetal resin such as polyvinyl acetatetal and polyvinyl butyral, and a carbonate resin. Including resin materials such as. Among these, urethane resin is preferably contained because the adhesion between the base material and the release layer can be further improved. The primer layer can contain two or more of the above resin materials.

In the second aspect, the content of the resin material in the primer layer is preferably 5% by mass or more and 90% by mass or less, more preferably 10% by mass or more and 80% by mass or less, and 15% by mass or more and 75% by mass or less. It is more preferably mass% or less. This makes it possible to improve the adhesion between the base material and the release layer and the information leakage prevention property of the intermediate transfer medium.

The primer layer may contain the above-mentioned additive as long as the characteristics of the present invention are not impaired.

In one embodiment, the primer layer is printed with an arbitrary pattern. This makes it possible to further improve the information leakage prevention property of the intermediate transfer medium. Specific examples of the pattern are as described above.

The thickness of the primer layer is preferably 0.05 μm or more and 20 μm or less, and more preferably 0.8 μm or more and 15 μm or less. This makes it possible to further improve the information leakage prevention property of the intermediate transfer medium.

In the primer layer, the above material is dispersed or dissolved in water or an appropriate solvent to obtain a coating liquid, which is used as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method and a rod. It can be formed by applying it on a substrate by a known means such as a coating method to form a coating film, and drying the coating film.

(Release layer)
In the second aspect, the release layer contains a urethane resin. The urethane resin is as described above. Since the release layer contains a urethane resin, the adhesion to the base material can be improved.

In the second aspect, the content of the urethane resin in the release layer is preferably 5% by mass, 75% by mass or less, and more preferably 10% by mass or more and 70% by mass or less. Thereby, the adhesion of the release layer to the substrate and the transferability of the intermediate transfer medium can be improved.

In one embodiment, the release layer can contain a resin material other than the urethane resin, for example, a (meth) acrylic resin, an ester resin, a cellulose resin, a styrene resin such as polystyrene and acrylonitrile styrene, an amide resin, a polyvinyl acet. Includes vinyl acetal resins such as acetal and polyvinyl butyral and resin materials such as carbonate resins.
Among these, it is preferable to contain a vinyl acetal resin because the adhesion between layers can be adjusted.
The release layer can contain two or more of the above resin materials.

In the second aspect, the release layer may contain a colorant, but the content thereof is preferably less than 10% by mass, more preferably less than 5% by mass, and the release layer is It is particularly preferable that it does not contain a coloring material. This makes it possible to prevent color transfer to the protective layer and the peeling layer provided in the transfer layer.

The release layer can contain the above-mentioned additives as long as the characteristics of the present invention are not impaired.

In one embodiment, the release layer is printed with an arbitrary pattern. This makes it possible to further improve the information leakage prevention property of the intermediate transfer medium. Specific examples of the pattern are as described above.

The thickness of the release layer is preferably 0.05 μm or more and 20 μm or less, and more preferably 1 μm or more and 15 μm or less.

(Transfer layer)
In the second aspect, the transfer layer comprises at least a protective layer and a receiving layer. Further, in one embodiment, the transfer layer further includes a release layer under the protective layer.

(Protective layer)
Since the materials and thicknesses constituting the protective layer are the same as those in the first aspect, the description thereof will be omitted here.

(Receptive layer)
Since the materials and thicknesses constituting the receiving layer are the same as those in the first aspect, the description thereof will be omitted here.

(Release layer)
Since the materials and thicknesses constituting the release layer are the same as those in the first aspect, the description thereof will be omitted here.

In the specification of the present application, the resins and the like constituting each layer are exemplarily described, but these resins may be homopolymers of the monomers constituting each resin, and constitute each resin. It may be a copolymer of a monomer having a main component and one or a plurality of other monomers, or a derivative thereof. For example, the acrylic resin may contain a monomer of acrylic acid or methacrylic acid, or a monomer of acrylic acid ester or methacrylic acid ester as a main component. Further, it may be a modified product of these resins. Further, resins other than those described in the present specification may be used.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1
As a base material, a PET film having a thickness of 12 μm was prepared. A primer layer forming coating solution having the following composition was applied to one surface of the PET film and dried to form a primer layer having a thickness of 1 μm.
<Coating liquid for forming a primer layer>
18 parts by mass of urethane resin (manufactured by DIC Corporation, Hydran (registered trademark) AP-40N)
・ 75 parts by mass of water ・ 25 parts by mass of isopropanol (IPA)

A release layer forming coating solution having the following composition was applied onto the primer layer and dried to form a release layer having a thickness of 1 μm.
<Coating liquid for mold release layer formation>
-Urethane resin 18 parts by mass-Polyurethane acetal acetal 42 parts by mass (Sekisui Chemical Co., Ltd., Eslek (registered trademark) KS-5)
・ Carbon black 40 parts by mass ・ Toluene 150 parts by mass ・ IPA 150 parts by mass

A coating liquid for forming a release layer having the following composition was applied onto the release layer and dried to form a release layer having a thickness of 1 μm.
<Coating liquid for forming a release layer>
(Meta) Acrylic resin 95 parts by mass (manufactured by Mitsubishi Chemical Corporation, Dianal (registered trademark) BR-87)
-Ester resin 5 parts by mass (manufactured by Toyobo Co., Ltd., Byron (registered trademark) 200)
・ Toluene 200 parts by mass ・ Methyl ethyl ketone (MEK) 200 parts by mass

A coating liquid for forming a protective layer having the following composition was applied onto the release layer and dried to form a protective layer having a thickness of 2 μm.
<Coating liquid for forming a protective layer>
20 parts by mass of ester resin (manufactured by Unitika Ltd., Elitel (registered trademark) UE-3320, Mn1800)
・ Toluene 40 parts by mass ・ MEK 40 parts by mass

A coating liquid for forming a receiving layer having the following composition is applied onto the protective layer and dried to form a receiving layer having a thickness of 1.0 μm, which is peeled off from a non-transfer layer provided with a substrate, a primer layer and a release layer. An intermediate transfer medium in which a layer, a protective layer, and a transfer layer having a receiving layer were laminated was obtained.
<Coating liquid for forming a receiving layer>
-95 parts by mass of vinyl chloride-vinyl acetate copolymer (manufactured by Nissin Chemical Industry Co., Ltd., Solveine (registered trademark) CNL)
・ Epoxy-modified silicone oil 5 parts by mass (manufactured by Shin-Etsu Chemical Co., Ltd., KP-1800U)
・ Toluene 200 parts by mass ・ MEK 200 parts by mass

Example 2
An intermediate transfer medium was obtained in the same manner as in Example 1 except that the composition of the coating liquid for forming the release layer was changed as follows.
<Coating liquid for mold release layer formation>
-Urethane resin 18 parts by mass-Polyurethane acetal acetal 72 parts by mass (Sekisui Chemical Co., Ltd., Eslek (registered trademark) KS-5)
・ Carbon black 10 parts by mass ・ Toluene 150 parts by mass ・ IPA 150 parts by mass

Example 3
An intermediate transfer medium was obtained in the same manner as in Example 1 except that the composition of the coating liquid for forming the release layer was changed as follows.
<Coating liquid for mold release layer formation>
・ 18 parts by mass of urethane resin ・ 17 parts by mass of polyvinyl acetal acetal (manufactured by Sekisui Chemical Co., Ltd., Eslek (registered trademark) KS-5)
・ Carbon black 65 parts by mass ・ Toluene 150 parts by mass ・ IPA 150 parts by mass

Example 4
An intermediate transfer medium was obtained in the same manner as in Example 1 except that the composition of the coating liquid for forming the release layer was changed as follows.
<Coating liquid for mold release layer formation>
-Urethane resin 40 parts by mass-Polyurethane acetal acetal 20 parts by mass (Sekisui Chemical Co., Ltd., Eslek (registered trademark) KS-5)
・ Carbon black 40 parts by mass ・ Toluene 150 parts by mass ・ IPA 150 parts by mass

Example 5
An intermediate transfer medium was obtained in the same manner as in Example 1 except that the composition of the coating liquid for forming the release layer was changed as follows.
<Coating liquid for mold release layer formation>
-Urethane resin 63.6 parts by mass-Polyurethane acetal acetal 27.3 parts by mass (Sekisui Chemical Co., Ltd., Eslek (registered trademark) KS-5)
・ Carbon black 9.1 parts by mass ・ Toluene 150 parts by mass ・ IPA 150 parts by mass

Example 6
An intermediate transfer medium was obtained in the same manner as in Example 1 except that the composition of the coating liquid for forming the primer layer was changed as follows.
<Coating liquid for forming a primer layer>
60 parts by mass of ester resin (manufactured by Toyobo Co., Ltd., Byron (registered trademark) 200)
・ Toluene 150 parts by mass ・ IPA 150 parts by mass

Example 7
An intermediate transfer medium was obtained in the same manner as in Example 1 except that the thickness of the release layer was changed to 0.1 μm.

Example 8
An intermediate transfer medium was obtained in the same manner as in Example 1 except that the compositions of the coating liquid for forming the primer layer and the coating liquid for forming the release layer were changed as follows.
<Coating liquid for forming a primer layer>
60 parts by mass of urethane resin (manufactured by DIC Corporation, Hydran (registered trademark) AP-40N)
・ Carbon black 40 parts by mass ・ Water 75 parts by mass ・ IPA 25 parts by mass

<Coating liquid for mold release layer formation>
-Urethane resin 18 parts by mass-Polyurethane acetal acetal 42 parts by mass (Sekisui Chemical Co., Ltd., Eslek (registered trademark) KS-5)
・ Toluene 150 parts by mass ・ IPA 150 parts by mass

Comparative Example 1
As a base material, a PET film having a thickness of 12 μm was prepared. A coating liquid for forming a release layer having the following composition was applied to one surface of the PET film and dried to form a release layer having a thickness of 1 μm.
<Coating liquid for forming a release layer>
(Meta) Acrylic resin 95 parts by mass (manufactured by Mitsubishi Chemical Corporation, Dianal (registered trademark) BR-87)
-Ester resin 5 parts by mass (manufactured by Toyobo Co., Ltd., Byron (registered trademark) 200)
・ Toluene 200 parts by mass ・ MEK 200 parts by mass

A coating liquid for forming a protective layer having the following composition was applied onto the release layer and dried to form a protective layer having a thickness of 2 μm.
<Coating liquid for forming a protective layer>
20 parts by mass of ester resin (manufactured by Unitika Ltd., Elitel (registered trademark) UE-3320)
・ Toluene 40 parts by mass ・ MEK 40 parts by mass

A coating liquid for forming a receiving layer having the following composition is applied and dried on the protective layer to form a receiving layer having a thickness of 1 μm, and a non-transfer layer (base material), a peeling layer, a protective layer, and a receiving layer are provided. An intermediate transfer medium in which a transfer layer was laminated was obtained.
<Coating liquid for forming a receiving layer>
-95 parts by mass of vinyl chloride-vinyl acetate copolymer (manufactured by Nissin Chemical Industry Co., Ltd., Solveine (registered trademark) CNL)
・ Epoxy-modified silicone oil 5 parts by mass (manufactured by Shin-Etsu Chemical Co., Ltd., KP-1800U)
・ Toluene 200 parts by mass ・ MEK 200 parts by mass

Comparative Example 2
An intermediate transfer medium was obtained in the same manner as in Example 1 except that the composition of the coating liquid for forming the release layer was changed as follows.
<Coating liquid for mold release layer formation>
-Urethane resin 18 parts by mass-Polyurethane acetal acetal 42 parts by mass (Sekisui Chemical Co., Ltd., Eslek (registered trademark) KS-5)
・ Carbon black 1 part by mass ・ Toluene 150 parts by mass ・ IPA 150 parts by mass

Comparative Example 3
An intermediate transfer medium was obtained in the same manner as in Example 1 except that the composition of the coating liquid for forming the protective layer was changed as follows.
<Coating liquid for forming a protective layer>
20 parts by mass of ester resin (manufactured by Toyobo Co., Ltd., Byron (registered trademark) 290, Mn22000)
・ Toluene 40 parts by mass ・ MEK 40 parts by mass

Comparative Example 4
An intermediate transfer medium was obtained in the same manner as in Example 8 except that the composition of the coating liquid for forming the release layer was changed as follows.
<Coating liquid for mold release layer formation>
60 parts by mass of ester resin (manufactured by Toyobo Co., Ltd., Byron (registered trademark) 200)
・ Toluene 150 parts by mass ・ IPA 150 parts by mass

<< Information leakage prevention evaluation >>
The intermediate transfer media obtained in the above Examples and Comparative Examples, the thermal transfer sheet prepared as described below, and the following thermal transfer printer were prepared.
Next, the thermal transfer sheet was heated by a thermal head provided in the thermal transfer printer to form a solid black image (0/255 image gradation) on the receiving layer provided in the intermediate transfer medium.
After image formation, the transfer layer included in the intermediate transfer medium was transferred onto a polyvinyl chloride card (hereinafter referred to as PVC card) manufactured by Dai Nippon Printing Co., Ltd. by a laminator to obtain a printed matter. The transfer temperature was 175 ° C.
After producing the printed matter, the non-transfer layer of the intermediate transfer medium was visually observed, and its information leakage prevention property was evaluated according to the following evaluation criteria. The evaluation results are summarized in Table 1. In addition, Comparative Example 4 could not be evaluated because the transfer layer could not be transferred.
(Evaluation criteria)
A: The image formed on the receiving layer could not be grasped at all from the non-transfer layer.
B: From the non-transfer layer, a part of the image formed on the receiving layer could be grasped, but it could not be completely grasped.
NG: The image formed on the receiving layer could be grasped from the non-transfer layer.

(Thermal transfer printer)
Thermal head: KEEP-57-12GAN2-STA (manufactured by Kyocera Corporation)
Average resistance of heating element: 3303Ω
Main scanning direction print density: 300 dpi
Sub-scanning direction print density: 300 dpi
Printing voltage: 18V
Line period: 2.0 msec. / Line
Printing start temperature: 35 ° C
Pulse duty ratio: 85%

(Preparation of thermal transfer sheet)
As a base material, a PET film having a thickness of 4.5 μm was prepared. A coating liquid for forming a back layer having the following composition was applied to one surface of the PET film so that the thickness at the time of drying was 0.8 μm, and the film was dried to form a back layer.
<Coating liquid for forming the back layer>
-Polyvinyl butyral 2 parts by mass (Sekisui Chemical Co., Ltd., Eslek (registered trademark) BX-1)
-Isocyanate compound 9.2 parts by mass (manufactured by DIC Corporation, Burnock (registered trademark) D750)
-Phosphoric acid ester surfactant 1.3 parts by mass (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Plysurf (registered trademark) A208)
-Talc 0.3 parts by mass (manufactured by Nippon Talc Industry Co., Ltd., Micro Ace (registered trademark) P-3)
・ Toluene 43.6 parts by mass ・ MEK 43.6 parts by mass

＜マゼンタ染料層形成用塗工液＞
・下記化学式（２）で表されるマゼンタ染料 ７質量部
・ポリビニルアセトアセタール １．８質量部
（積水化学工業（株）製、エスレック（登録商標）ＫＳ－５）
・ポリビニルブチラール ０．９質量部
（積水化学工業（株）製、エスレック（登録商標）ＢＨ－Ｓ）
・セルロース樹脂 ０．３質量部
（日新化成（株）製、エトセルＳＴＤ４５）
・シリコーン ０．１２質量部
（信越化学工業（株）製、Ｘ－２２－３９３９）
・トルエン ４５質量部
・ＭＥＫ ４５質量部

＜シアン染料層形成用塗工液＞
・下記化学式（３）で表されるシアン染料 ７質量部
・ポリビニルアセトアセタール １．８質量部
（積水化学工業（株）製、エスレック（登録商標）ＫＳ－５）
・ポリビニルブチラール ０．９質量部
（積水化学工業（株）製、エスレック（登録商標）ＢＨ－Ｓ）
・セルロース樹脂 ０．３質量部
（日新化成（株）製、エトセルＳＴＤ４５）
・シリコーン ０．０６質量部
（信越化学工業（株）製、Ｘ－２２－３９３９）
・トルエン ４５質量部
・ＭＥＫ ４５質量部

On the other surface of the PET film, a coating liquid for forming a yellow dye layer, a coating liquid for forming a magenta dye layer, and a coating liquid for forming a cyan dye layer having the following compositions have a thickness of 0.6 μm when dried. The surface was sequentially applied and dried to form a dye layer, and a thermal transfer sheet was obtained.
<Coating liquid for forming a yellow dye layer>
・ 7 parts by mass of yellow dye represented by the following chemical formula (1) ・ 1.8 parts by mass of polyvinyl acetal (manufactured by Sekisui Chemical Co., Ltd., Eslek (registered trademark) KS-5)
-Polyvinyl butyral 0.9 parts by mass (Sekisui Chemical Co., Ltd., Eslek (registered trademark) BH-S)
-Cellulose resin 0.3 parts by mass (manufactured by Nissin Kasei Co., Ltd., Etocell STD45)
-Silicone 0.06 parts by mass (manufactured by Shin-Etsu Chemical Co., Ltd., X-22-3939)
・ 45 parts by mass of toluene ・ 45 parts by mass of MEK

<Coating liquid for forming magenta dye layer>
・ 7 parts by mass of magenta dye represented by the following chemical formula (2) ・ 1.8 parts by mass of polyvinyl acetal (manufactured by Sekisui Chemical Co., Ltd., Eslek (registered trademark) KS-5)
-Polyvinyl butyral 0.9 parts by mass (Sekisui Chemical Co., Ltd., Eslek (registered trademark) BH-S)
-Cellulose resin 0.3 parts by mass (manufactured by Nissin Kasei Co., Ltd., Etocell STD45)
-Silicone 0.12 parts by mass (manufactured by Shin-Etsu Chemical Co., Ltd., X-22-3939)
・ 45 parts by mass of toluene ・ 45 parts by mass of MEK

<Cyan dye layer forming coating liquid>
-Cyan dye represented by the following chemical formula (3) 7 parts by mass-Polyvinyl acetal acetal 1.8 parts by mass (manufactured by Sekisui Chemical Co., Ltd., Eslek (registered trademark) KS-5)
-Polyvinyl butyral 0.9 parts by mass (Sekisui Chemical Co., Ltd., Eslek (registered trademark) BH-S)
-Cellulose resin 0.3 parts by mass (manufactured by Nissin Kasei Co., Ltd., Etocell STD45)
-Silicone 0.06 parts by mass (manufactured by Shin-Etsu Chemical Co., Ltd., X-22-3939)
・ 45 parts by mass of toluene ・ 45 parts by mass of MEK

<< OD value measurement >>
As described above, the OD value of the intermediate transfer medium (non-transfer layer) after transfer of the transfer layer was measured by a Macbeth transmission densitometer (TR-924, manufactured by Macbeth) and summarized in Table 1.

<< Transcription evaluation >>
As described above, the transfer layer transferred onto the PVC card was visually observed, and its transferability was evaluated according to the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
A: The occurrence of tailing of the transfer layer could not be confirmed.
B: Tailing occurred in the transfer layer, but there was no problem in practical use.
NG: The transfer layer did not peel off from the non-transfer layer and could not be transferred.

<< Evaluation of color transfer prevention >>
As described above, the transfer layer transferred onto the PVC card was visually observed, and the color transfer prevention property was evaluated according to the following evaluation criteria. The evaluation results are summarized in Table 1. The intermediate transfer media of Comparative Examples 1 and 3 did not have a release layer and a primer layer, and were not evaluated. Further, Comparative Example 4 could not be evaluated because the transfer layer could not be transferred.
(Evaluation criteria)
A: No color transfer from the colored release layer or primer layer of the non-transfer layer to the transfer layer was observed.
B: Color transfer from the colored release layer or primer layer to the transfer layer was observed in less than 5% of the total area.
C: Color transfer from the colored release layer or primer layer to the transfer layer was observed in the region of 5% or more and 20% or less of the whole.
NG: Color transfer from the colored release layer or primer layer to the transfer layer was observed in the region of 20% or more.

10: Intermediate transfer medium, 11: Substrate, 12: Release layer, 13: Non-transfer layer, 14: Protective layer, 15: Receptive layer, 16: Transfer layer, 17: Exfoliation layer, 18: Primer layer, 20: Intermediate transfer medium, 21: substrate, 22: primer layer, 23: release layer, 24: non-transfer layer, 25: protective layer, 26: receptive layer, 27: transfer layer, 28: release layer

Claims (13)

It comprises a non-transfer layer with a substrate and a release layer, and a transfer layer with a protective layer and a receptive layer.
The release layer contains a coloring material and a urethane resin, and contains
An intermediate transfer medium characterized in that the OD value of the non-transfer layer is 0.2 or more. The intermediate transfer medium according to claim 1, wherein the content of the coloring material in the release layer is 5% by mass or more and 70% by mass or less. The intermediate transfer medium according to claim 1 or 2, wherein the content of the urethane resin in the release layer is 5% by mass or more and 75% by mass or less. The intermediate transfer medium according to any one of claims 1 to 3, wherein the release layer has a thickness of 0.15 μm or more and 20 μm or less. The intermediate transfer medium according to any one of claims 1 to 4, wherein the non-transfer layer comprises a primer layer between the base material and the release layer. The intermediate transfer medium according to claim 5, wherein the primer layer contains a urethane resin. The intermediate transfer medium according to any one of claims 1 to 6, wherein the protective layer contains a resin material having a number average molecular weight of 1500 or more and 18000 or less. It comprises a non-transfer layer with a substrate, a primer layer and a release layer, and a transfer layer with a protective layer and a receptive layer.
The primer layer contains a colorant and contains
The release layer contains urethane resin and contains
An intermediate transfer medium characterized in that the OD value of the non-transfer layer is 0.2 or more. The intermediate transfer medium according to claim 8, wherein the content of the coloring material in the primer layer is 10% by mass or more and 70% by mass or less. The intermediate transfer medium according to claim 8 or 9, wherein the primer layer has a thickness of 0.05 μm or more and 20 μm or less. The intermediate transfer medium according to any one of claims 8 to 10, wherein the content of the urethane resin in the release layer is 5% by mass or more and 75% by mass or less. The intermediate transfer medium according to any one of claims 8 to 11, wherein the primer layer contains a urethane resin. The intermediate transfer medium according to any one of claims 8 to 12, wherein the protective layer contains a resin material having a number average molecular weight of 1500 or more and 18000 or less.

Images