JP2003312151A - Thermal transfer sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal transfer sheet which eliminates necessity of a mold release layer provided on a protective layer region without a problem such as blocking or the like at a winding time, after a back surface is coated on a base material without high base material acquisition cost, and which can raise the gloss of a printed matter with the protective layer. <P>SOLUTION: The thermal transfer sheet comprises: at least one color dye layer; and a thermal transferable protective layer alternately laminated on one surface of the base material. The sheet further comprises: a partial protective layer provided on the one surface of the base material; an easy adhesive layer provided on the overall surface of the protective layer and the base material; and a dye layer provided on a region not disposing the protective layer at a lower position on the easy adhesive layer. It is preferred to provide the adhesive layer on the region providing the protective layer at the lower position on the easy adhesive layer. It is preferred to provide a sensing mark in one or both between the dye layer and the thermal transferable protective layer, and between a plurality of colors of dye layers. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer sheet in which a dye layer of at least one color and a thermal transferable protective layer are provided on one surface of a base material in a surface-sequential manner. The present invention relates to a thermal transfer sheet in which an adhesive layer is applied later.

[0002]

2. Description of the Related Art Conventionally, a thermal transfer method has been used to form a gradation image or a monotone image such as characters and symbols on an image receiving sheet. As the thermal transfer method, a sublimation transfer method and a hot melt transfer method are known. The sublimation transfer method is a method in which a thermal transfer sheet having a dye layer obtained by dissolving or dispersing a sublimable dye used as a coloring material in a binder resin is carried on a base material on an image receiving sheet, and a heating means such as a thermal head or a laser is used to form an image. By applying energy according to information, the dye contained in the sublimable dye layer on the thermal transfer sheet is transferred to the image receiving sheet to form an image.
The sublimation transfer method can control the amount of dye transfer in dot units according to the amount of energy applied to the thermal transfer sheet, which allows the formation of full-color images with gradation and high quality comparable to that of silver halide photographs. Images can be formed. Therefore, the sublimation transfer method has attracted attention and is used as an information recording means in various fields.

Due to the development of various hardware and software related to multimedia, this thermal transfer method is used for computer graphics, still image by satellite communication and C
The market is expanding as a full-color hard copy system for digital images represented by D-ROM and other analog images and analog images such as videos. There are a wide variety of specific uses of the image receiving sheet by the thermal transfer method. Typical examples include printing proofs, image output, and CA.
Design and output of D / CAM etc., various medical analysis equipment such as CT scan and endoscopic camera, output use of measuring equipment and as an alternative to instant photography,
In addition, output of identification cards, ID cards, credit cards, facial photographs of other cards, etc., composite photographs at amusement facilities such as amusement parks, game arcades, museums, aquariums, etc. .

However, an image formed by such a sublimation transfer method is not so good in durability such as light resistance and abrasion resistance as compared with an image of a silver salt photograph. Therefore, as one means for improving the durability of the image formed by the transfer recording method,
There is a method of covering an image with a protective layer using a protective layer transfer sheet having a heat transferable protective layer provided on a substrate.
Then, on the same substrate with the dye layer used for image formation and this protective layer, using a thermal transfer sheet provided separately in a frame-sequential manner, once set in a thermal transfer printer, the thermal transfer image and the image on the image The thermal transfer protection layer can be easily formed.

However, when the above-mentioned protective layer and dye layer are provided on the same base material, when a thermal transfer image is formed on the image receiving sheet by the dye, an abnormal transfer occurs in which the dye layer is transferred to the image receiving sheet. In order to prevent it, the adhesion between the base material and the dye layer is required to be high, and the protective layer is required to have releasability from the base material when thermally transferred onto the image of the printed matter. When the dye layer and the protective layer are provided on the same substrate,
By using an easily-adhesive-treated substrate, or by providing an easily-adhesive layer on the substrate, the adhesiveness with the dye layer is first increased, and a release layer is provided on the substrate side in the region where the protective layer is provided, It has often been done to provide a protective layer on it.

[0006]

The above-mentioned substrate which has been subjected to the easy-adhesion treatment is incorporated into a process such as stretching when the easy-adhesion treatment is carried out, so that the substrate can be extremely thinned. Although it can provide sufficient adhesive strength, its base material is very expensive to obtain, and problems such as blocking tend to occur during winding after coating the back layer on the base material. . Further, when a thermal transfer sheet formed by sequentially coating a release layer and a protective layer on the above-mentioned substrate is used to thermally transfer the protective layer to a printed matter, the protective layer to be transferred is an interface with the release layer. Since the printed matter with the protective layer is peeled off, the surface of the protective layer is poor in smoothness, and it is difficult to obtain a highly glossy printed matter.

Therefore, in order to solve the above problems, the present invention provides a thermal transfer sheet in which a dye layer of at least one color and a thermal transferable protective layer are provided on one surface of a substrate in a surface sequential manner. Material acquisition cost is not high, there is no problem such as blocking at the time of winding after coating the back layer on the base material, the release layer provided in the protective layer area becomes unnecessary, It is an object of the present invention to provide a thermal transfer sheet capable of increasing the gloss of a printed matter.

[0008]

In order to achieve the above object, in the present invention, a thermal transfer sheet having a dye layer of at least one color and a thermal transferable protective layer provided on one surface of a substrate in a surface sequential manner. In the above, a protective layer is partially provided on one surface of the base material, then an easy-adhesion layer is provided on the entire surface of the protective layer and the base material, and then on the easy-adhesion layer and with the protective layer below. It is characterized in that a dye layer is provided in a region which is not located. The easy-adhesion layer preferably contains a homopolymer of N-vinylpyrrolidone or a copolymer of N-vinylpyrrolidone and other components. It is preferable to provide an adhesive layer on the above-mentioned easy-adhesion layer and in a region where the protective layer is provided below. Between the dye layer and the heat transferable protective layer, between the dye layers of a plurality of colors, either or both, it is preferable to provide a detection mark, thereby,
It becomes a register when coating a dye layer and a heat transferable protective layer on a substrate in a frame-sequential manner, and using this heat transfer sheet,
At the time of thermal transfer to the image receiving sheet, the thermal transfer image and the thermal transfer protective layer can be accurately aligned on the image receiving sheet by detecting the detection mark of the transfer area of the thermal transfer sheet with a printer and reading the area accurately.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below with reference to preferred embodiments. FIG. 1 is a schematic cross-sectional view showing one embodiment of the thermal transfer sheet 1 of the present invention, in which a protective layer 4 is partially provided on one surface of a substrate 2, and the protective layer 4 and the protective layer 4 are provided. The easy-adhesion layer 3 is provided on the entire surface of the base material 2 on which the is not provided. And the protective layer 4
The yellow dye layer (Y), the magenta dye layer (M), and the cyan dye layer (C) of the dye layer 5 are frame-sequentially provided between the protective layer 4 and the next protective layer 4 except the formation region of It is provided. The region where the protective layer 4 and the easy-adhesion layer 3 are laminated on the base material 2 is the thermal transferable protective layer 6, and when the region is heated, the thermal transferable protective layer 6 consisting of two layers is transferred to the transfer target. Transcribed. The dye layer 5 of three colors and the unit 9 of the thermal transferable protective layer 6 are repeatedly formed in the length direction of the thermal transfer sheet 1.

FIG. 2 is a schematic cross-sectional view showing another embodiment of the thermal transfer sheet 1 of the present invention. A protective layer 4 is partially provided on one surface of a base material 2, and the protective layer 4 is provided on the protective layer 4. Protective layer 4
The easy-adhesion layer 3 is provided on the entire surface of the base material 2 on which the is not provided. Then, the adhesive layer 7 is provided on the easy-adhesion layer 3 in the region where the protective layer 4 is located below, and in this case, the protective layer 4, the easy-adhesion layer 3, and the adhesive layer 7 are provided. The three layers are transferred to the transfer target as the thermal transferable protective layer 6. Further, the heat resistant slipping layer 10 is provided on the surface of the base material 2 opposite to the surface on which the protective layer 4 is provided, so that fusion with the thermal head can be prevented and running performance can be improved. Further, since the adhesive layer 7 is provided on the outermost surface layer of the thermal transferable protective layer 6, the transferability and the adhesiveness to the transfer target are improved. The yellow dye layer (Y) and the magenta dye layer (M) of the dye layer 5 are provided between the heat transferable protection layer 6 and the next heat transferable protection layer 6 except the area where the heat transferable protection layer 6 is formed. A cyan dye layer (C) is provided in a frame-sequential manner, and the dye layer 5 of three colors and the unit 9 of the heat transferable protective layer 6 are repeatedly formed in the length direction of the heat transfer sheet 1.

FIG. 3 is a schematic sectional view showing another embodiment of the thermal transfer sheet 1 of the present invention. In addition to the form shown in FIG. 2, a yellow dye layer (Y) and a magenta dye layer (M) are added. Between the magenta dye layer (M) and the cyan dye layer (C), between the cyan dye layer (C) and the heat transferable protective layer 6, and between the heat transferable protection layer 6 and the yellow dye layer (Y). Is provided with a detection mark 8.

Each element constituting the thermal transfer sheet of the present invention will be described below. (Substrate) The substrate 2 used in the thermal transfer sheet of the present invention may be any substrate as long as it has conventionally known heat resistance and strength to some extent, and for example, 0.5 to 50.
A paper having a thickness of about μm, preferably about 2 to 10 μm, and various processed papers can be used, and polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride, polystyrene, nylon, polyimide, polyvinylidene chloride. , Polyvinyl alcohol, polyphenylene sulfide, aramid,
A film such as a fluororesin can also be used and these may be compounded. A polyester film is preferable, and a polyethylene terephthalate film is particularly preferable. In order to improve the adhesiveness with the layer provided on the substrate, as the adhesion treatment, corona discharge treatment, plasma treatment, low temperature plasma treatment, flame treatment, ozone treatment, ultraviolet treatment, radiation treatment, rough surface treatment Chemical treatment, chemical treatment, etc. can be applied.

(Easy Adhesive Layer) As a resin constituting the easy adhesive layer 3 formed of the thermal transfer sheet of the present invention, preferred ones are:
Examples thereof include polyester resins, acrylic resins, urethane resins, alkyd resins, homopolymers of N-vinylpyrrolidone, and copolymers of N-vinylpyrrolidone and other components. Further, in order to improve the adhesiveness to the substrate or the dye layer, the protective layer, or the environmental preservation property,
The easily adhesive layer has a melamine compound, an isocyanate compound, an epoxy compound, a compound containing an oxazoline group,
It is preferable to add a chelate compound or the like.

The above N-vinylpyrrolidone includes N
-Vinyl-2-pyrrolidone, N-vinyl-3-pyrrolidone, N-vinyl-4-pyrrolidone, etc., and a homopolymer of this vinylpyrrolidone (a homopolymer of the same monomer species) or a copolymer of these different monomers. Polymers may be mentioned. Such polyvinylpyrrolidone resin has a Fickencher official K value of K-60 to
K-120 grade can be used, and in number average molecular weight,
It is about 30,000 to 280,000. By using this polyvinylpyrrolidone resin for the easy-adhesion layer, the thermal transfer protection layer has improved plasticizer resistance, scratch resistance, and the like, and the transfer sensitivity is enhanced, and uneven transfer and defective foil cutting of the protective layer transfer are prevented. It When the polyvinylpyrrolidone resin having a K value of less than 60 (K-15, K-30) is used, the effect of improving the transfer sensitivity in printing cannot be exhibited.

Further, a copolymer of the above-mentioned N-vinylpyrrolidone and another copolymerizable monomer can also be used. Examples of the copolymerizable monomer other than N-vinylpyrrolidone include vinyl such as styrene, vinyl acetate, acrylic acid ester, acrylonitrile, maleic anhydride, vinyl chloride (fluoride), vinylidene chloride (fluoride, cyanide) and the like. Examples include monomers. The vinyl monomer and N-
Copolymers obtained by radical copolymerization with vinylpyrrolidone can be used. Further, a block copolymer or a graft copolymer of polyvinylpyrrolidone with a polyester resin, a polycarbonate resin, a polyurethane resin, an epoxy resin, an acetal resin, a butyral resin, a formal resin, a phenoxy resin, a cellulose resin or the like can also be used.

Further, in the easily adhesive layer, a resin may be mixed in addition to the polyvinylpyrrolidone resin to improve the adhesiveness. As the resin, styrene, vinyl acetate, acrylic ester, acrylonitrile, maleic anhydride, vinyl chloride (fluorinated), chloride (fluorinated, cyanated)
Examples thereof include polymers (copolymers) obtained from vinyl monomers such as vinylidene, polyester resins, polycarbonate resins, polyurethane resins, epoxy resins, acetal resins, butyral resins, formal resins, phenoxy resins, cellulose resins and polyvinyl alcohol resins. Such a resin component is preferably added and used in a proportion of 1 to 30% by weight based on the solid content of the entire easy-adhesion layer. If the addition amount of this resin component is small, sufficient adhesiveness cannot be exhibited, and if the addition amount of this resin component is too large, the effect of improving the transfer sensitivity of polyvinylpyrrolidone cannot be exhibited sufficiently.

An organic ultraviolet absorber or an inorganic ultraviolet absorber may be added to the easy-adhesion layer to improve the light resistance of the protective layer. Organic UV absorbers include salicylate, benzophenone, benzotriazole,
Non-reactive UV absorbers such as triazine-based, substituted acrylonitrile-based, nickel chelate-based, hindered amine-based and these non-reactive UV absorbers, for example, addition polymerization of vinyl group, acryloyl group, methacryloyl group, etc. Double bond, or alcoholic hydroxyl group, amino group,
What introduced the carboxyl group, the epoxy group, the isocyanate group, etc., and copolymerized or grafted to the thermoplastic resin, such as an acrylic resin, can be used. Among these UV absorbers, benzophenone-based, benzotriazole-based, and triazine-based UV absorbers have high UV-absorbing properties, and are particularly preferable.

These UV absorbers may be used in combination with UV absorbers of different systems so as to cover an effective UV absorption wavelength range, or non-reactive UV absorbers may be used, depending on the characteristics of the dye used for image formation. It is preferable to use a mixture of a plurality of absorbers having different structures so that the ultraviolet absorber does not precipitate. As the inorganic UV absorber, a titanium oxide-based, zinc oxide-based, cerium oxide-based, or other filler having a UV-absorbing ability can be used. In addition to the above-mentioned inorganic filler as an ultraviolet absorber, silica,
Fillers of alumina, other metal oxides, and metal sulfides can also be used to improve the adhesiveness and the like.
The particle size of these fillers is preferably fine particles having an average particle size of 0.1 μm or less in order to maintain the transparency of the protective layer.

In order to form an easy-adhesion layer, the above materials are prepared by dissolving or dispersing in a solvent selected from acetone, methyl ethyl ketone, toluene, xylene, alcohol, etc., or water, etc., which is selected according to coating suitability. It can be formed by preparing the following coating liquid, applying it to the surface of the substrate using a conventional coating means such as a gravure coater, a die coater, a roll coater, and a wire, and then drying and solidifying. The dry coating amount is 0.01 to 5 g / m ² , preferably 0.0.
It is 5 to 1 g / m ² .

(Protective Layer) As the constituents of the thermal transferable protective layer 6 in the thermal transfer sheet of the present invention, the above-mentioned easy-adhesion layer, protective layer 4, and further adhesive layer can be mentioned. This protective layer mainly serves to impart durability such as light resistance and abrasion resistance. As the resin constituting the protective layer, various resins conventionally known as protective layer forming resins can be used. As the protective layer forming resin, for example, polyester resin, polystyrene resin, acrylic resin, polyurethane resin, acrylic urethane resin, polyvinylpyrrolidone resin similar to those described in the easy-adhesion layer, a resin obtained by modifying each of these resins with silicone. Examples thereof include a mixture of each of these resins, an ionizing radiation curable resin, an ultraviolet blocking resin, and the like.

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

The protective layer containing the UV-blocking resin is mainly intended to impart light resistance to the printed matter. As the ultraviolet blocking resin, for example, a resin obtained by reacting and binding a reactive ultraviolet absorber with a thermoplastic resin or the above ionizing radiation curable resin can be used. More specifically, addition-polymerizable double-layers are added to conventionally known non-reactive organic UV absorbers such as salicylates, benzophenones, benzotriazoles, substituted acrylonitriles, nickel chelates, and hindered amines. A bond (eg, vinyl group, acryloyl group, methacryloyl group, etc.),
The thing introduce | transducing reactive groups, such as an alcoholic hydroxyl group, an amino group, a carboxyl group, an epoxy group, and an isocyanate group, can be illustrated.

In order to provide the protective layer on the substrate, a coating solution containing necessary components is prepared and the coating solution is applied by a conventional coating means such as a gravure coater, a die coater, a roll coater and a wire. , Coating on a substrate and drying. This protective layer is usually formed with a dry coating amount of about 0.5 to 10 g / m ² , though it depends on the kind of the protective layer forming resin.

(Adhesive Layer) As the uppermost layer of the thermal transferable protective layer in the thermal transfer sheet of the present invention, the adhesive layer 7 is provided on the easily adhesive layer and in the region where the protective layer is located below.
Can be provided. This adhesive layer can improve the transferability and the adhesiveness of the thermal transferable protective layer to the transferred body. As the adhesive layer, any of conventionally known pressure-sensitive adhesives and heat-sensitive adhesives can be used, but the glass transition temperature is 50 ° C to 50 ° C.
It is more preferably formed from a thermoplastic resin at 80 ° C., for example, polyester resin, polycarbonate resin, butyral resin, acrylic resin, ultraviolet blocking resin, epoxy resin, vinyl chloride-vinyl acetate copolymer resin, polyamide resin, chloride resin. It is preferable to select a resin having an appropriate glass transition temperature from resins having good adhesiveness at the time of heat such as vinyl resin. Further, the adhesive layer may contain the same polyvinylpyrrolidone resin as that described for the easy-adhesion layer to improve the transfer sensitivity of the protective layer.

As the ultraviolet blocking resin, a resin obtained by reacting and bonding a reactive ultraviolet absorber with a thermoplastic resin or an ionizing radiation curable resin can be used as in the case of the protective layer. . In addition, the adhesive layer may contain an inorganic filler such as fine particle silica, alumina, calcium carbonate, talc, and clay, and an organic filler such as an acrylic resin, a polyester resin, a melamine resin, an epoxy resin, and a polyethylene resin. The content is preferably about 0.1% to 30% in terms of the resin solid content ratio of the adhesive layer. The filler preferably has an average particle size of about 1 to 10 μm. When the average particle size is less than 1 μm, the thermal transfer sheet and the image receiving sheet are less likely to slip, and meandering and wrinkling are likely to occur during transfer of the protective layer. . The average particle size is 1
If it exceeds 0 μm, the transparency of the heat transferable protective layer decreases,
It is not preferable because it makes the underlying thermal transfer image unclear. Further, the same organic UV absorber and inorganic UV absorber as those described for the easy-adhesion layer can be added to the adhesive layer to improve the light resistance of the protective layer. The resin constituting the adhesive layer as described above and, if necessary, a coating liquid containing an additive are applied and dried, so that the coating amount (drying amount) is preferably about 0.5 to 10 g / m ^2. Forming an adhesive layer.

(Dye layer) The dye layer 5 provided in the thermal transfer sheet of the present invention is a layer in which a dye is carried by an arbitrary binder. The dye to be used is a dye that melts, diffuses, or sublimes by heat, and the dyes used in conventionally known thermal transfer sheets can be effectively used in the present invention. Properties and solubility in binder are selected. Preferred dyes include, for example, diarylmethane-based, triarylmethane-based, thiazole-based, methine-based such as merocyanine, indoaniline, acetophenone azomethine, pyrazoloazomethine,
Azomethine type represented by imidazole azomethine, imidazoazomethine, pyridone azomethine, xanthene type,
Oxazine type, dicyanostyrene, cyanomethylene type represented by tricyanostyrene, thiazine type, azine type, acridine type, benzeneazo type, pyridone azo, thiophenazo, isothiazole azo, pyrrole azo, pyral azo, imidazole azo, thiadiazole azo,
Azo series such as triazole azo and diazo, spiropyran series, indolino spiropyran series, fluoran series, rhodamine lactam series, naphthoquinone series, anthraquinone series,
Examples include quinophthalone type.

Specifically, for example, the following dyes are used. C.I. (Color Index) Disperse Yellow 51, 3, 54, 79, 60, 23, 7, 141 C.I. Disperse Blue 24, 56, 14, 301,
334, 165, 19, 72, 87, 287, 154
26,354 CI Disperse Red 135,146,59,1,
73,60,167 CI Disperse Orange 149 CI Disperse Violet 4,13,26,3
6,56,31 CI Disperse Yellow 56,14,16,29,
201 CI Solvent Blue 70,35,63,36,5
0, 49, 111, 105, 97, 11 CI Solvent Red 135, 81, 18, 25, 1
9,23,24,143,146,182 CI Solvent Violet 13 CI Solvent Black 3 CI Solvent Green 3

For example, as the cyan dye, Kayaset Blue 714 (Nippon Kayaku, Solvent Blue 63),
Foron Brilliant Blue-SR (Sand, Disperse Blue 354), Waxolin AP-FW (IC
I, Solvent Blue 36), as a magenta dye,
MS-REDG (Mitsui Toatsu, Disperse Red 6
0), Macrolex Violet R (manufactured by Bayer, Disperse Violet 26), as a yellow dye, Foron Brilliant Yellow S-6GL (manufactured by Sand, Disperse Yellow 231), Macrolex Yellow 6G (manufactured by Bayer, Disperse Yellow 201), etc. The dyes of can be used.

As the resin binder for supporting the dye as described above, known ones can be used, and examples thereof include cellulosic resins such as ethyl cellulose, ethyl hydroxycellulose, hydroxypropyl cellulose, methyl cellulose and cellulose acetate, polyvinyl alcohol, Examples include vinyl resins such as polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, and polyvinylpyrrolidone, acrylic resins such as poly (meth) acrylate and poly (meth) acrylamide, polyurethane resins, polyamide resins, polyester resins, etc. Alternatively, they can be optionally used by mixing. Among these, polyvinyl butyral and polyvinyl acetal are preferable from the viewpoints of dye migration and storability as a thermal transfer sheet.

In the present invention, the following releasable graft copolymer can be used as a releasing agent or a resin binder instead of the above binder resin. These releasable graft copolymers are obtained by graft-polymerizing at least one releasable segment selected from polysiloxane segment, fluorohydrocarbon segment, fluorocarbon segment or long-chain alkyl segment on the polymer main chain. is there.

Of these, particularly preferred is a graft copolymer obtained by grafting a polysiloxane segment on the main chain made of polyvinyl acetal resin. To produce the above graft copolymer, for example,
It is obtained by reacting a polysiloxane having a functional group with a diisocyanate to produce a grafting silicone chain, and grafting the grafting silicone chain onto polyvinyl acetal. Specifically, for example, in a solvent in which hexamethylene diisocyanate and dimethylpolysiloxane having a hydroxyl group at one end are mixed with methyl ethyl ketone and methyl isobutyl ketone in a ratio of 1: 1, a tin-based catalyst (for example, dibutyltin) is added in an amount of 0.01 ~ 1
A grafting silicone chain is produced at a reaction temperature of about 00 ° C. Next, the silicone graft polyvinyl acetal resin can be produced by reacting the grafting silicone chain and the polyvinyl acetal resin in a solvent in which methyl ethyl ketone and methyl isobutyl ketone are mixed at a ratio of 1: 1.

When such a graft copolymer is added to the dye layer to be used as a mold releasing agent, the content of the mold releasing segment in the mold releasing agent is such that the amount of the mold releasing segment in the graft copolymer is 10. A proportion of ˜80% by weight is preferable, and if the amount of the releasable segment is too small, the releasability becomes insufficient, while if it is too large, the compatibility with the resin binder decreases and problems such as dye migration may occur. It is not preferable because it occurs. When the above releasing agent is added to the dye layer, it can be used alone or as a mixture,
The addition amount is 1 to 100 parts by weight of the resin binder.
40 parts by weight is preferred. If the addition amount is too small, the releasing effect is insufficient, and if the addition amount is too large, the migration of the dye in the dye layer and the film strength are lowered, and the discoloration of the dye in the dye layer and the storability of the thermal transfer sheet are problematic. It is not preferable because it occurs. On the other hand, when the above graft copolymer is used as the resin binder of the dye layer, the content of the releasing segment in the resin binder is such that the amount of the releasing segment in the resin binder is 0.5 to 40% by weight. It is preferable that the ratio is too small, and if the amount of the releasable segment is too small, the releasability of the dye layer becomes insufficient. Conversely, if it is too large, the migration of the dye in the dye layer and the film strength as a resin decrease. In addition, discoloration of the dye in the dye layer and storability of the heat transfer sheet may occur, which is not preferable.

The dye layer is preferably prepared by adding various additives to the dye and resin binder as described above, if necessary, and dissolving them in an appropriate organic solvent or gravure-printing a dispersion prepared by dispersing in an organic solvent or water. Method, a screen printing method, a reverse roll coating method using a gravure plate, and the like can be applied onto the substrate and dried to form a dye layer. In this case, the dye layer may be provided by one application, but may be provided by two applications.
By forming in this way, the dye concentration per unit area can be increased. Further, the outermost layer of the dye layer is a layer containing a release resin as described above,
Even when printing is performed on an image receptor such as a plastic card having a poor releasability component at the time of printing, thermal fusion can be prevented. Dye layer formed as above is 0.2-5.0g
/ M ² , preferably a coating amount (dry) of about 0.3 to 2.0 g / m ² . Monochromatic printing may be used for this printing, but multicolor printing of three colors of yellow, magenta, and cyan, and four colors of black added is preferable so that a full-color image can be formed.

(Heat Melt Ink Layer) The heat transfer sheet of the present invention.
On one side of the base material, a dye layer of at least one color and a heat
A transferable protective layer is provided in a frame-sequential manner.
Dye layer, heat-fusible ink layer, on the side where the material layer is provided,
It is also possible to provide the heat transferable protective layer in the order of frame order.
It Specifically, the product of substrate / easy adhesion layer / heat-meltable ink layer
It becomes a layered form. Form this hot-melt ink layer
For the heat-meltable ink layer, if necessary, on the easy-adhesion layer.
A release layer, etc. can be formed, and then appropriate coloring is applied.
Heat-meltable resin containing agent, vehicle and other additives
Hot melt coat, hot lacquer coat,
Lavia coat, gravure reverse coat, roll coat
It is applied by a known method such as. Coating of hot-melt ink layer
The amount of work is usually 0.2 to 10 g / m ²(At the time of dryness)
It

As the colorant for the heat-fusible ink layer, it is preferable to use a black colorant, which is convenient mainly for recording clear characters and symbols in high density. As the vehicle, for example, a wax, a mixture of a wax and a drying oil, a resin, a mineral oil, cellulose, a rubber derivative, or the like is used. As the wax, microcrystalline wax, carnauba wax, paraffin wax,
Examples thereof include Fischer-Tropsch wax, low molecular weight polyethylene, wood wax, beeswax, spermaceti wax, ivowa wax, wool wax, shellac wax, candelilla wax, petrolatum, partially modified wax, fatty acid ester, fatty acid amide and the like.

(Heat-Resistant Sliding Layer) On the surface (back side) of the above-mentioned substrate on which the dye layer is not provided, the thermal transfer sheet of the present invention is used in addition to preventing fusion of the thermal head and improving running property. In order to prevent the back surface from adhering to the dye layer and the surface of the heat transferable protective layer when wound in a roll, the heat resistant slipping layer 10 provided with heat resistant slipping property and releasing property on the back surface side of the base material. It is desirable to provide it. As the resin forming the heat resistant slipping layer, polyester resin, polyacrylic ester resin, polyvinyl acetate resin, styrene acrylate resin, polyurethane resin, polyolefin resin, polystyrene resin, polyvinyl chloride resin , Polyether resin, polyamide resin, polyimide resin, polyamideimide resin, polycarbonate resin, polyethylene resin, polypropylene resin, polyacrylate resin, polyacrylamide resin, polyvinyl chloride resin, polyvinyl butyral resin, polyvinyl acetoacetal Resin or the like can be used. Further, various crosslinking agents may be used for the purpose of improving the heat resistance, coating property, adhesion and the like of these resins, and polyisocyanate is generally used. In addition, wax, higher fatty acid amides, esters, release agents such as surfactants, organic powders such as fluororesins, silica
Inorganic particles such as clay, talc, mica and calcium carbonate can be contained.

(Detection Mark) The thermal transfer sheet of the present invention can be provided with a detection mark 8 as shown in FIGS. 2 and 3 to indicate the start position of thermal transfer image formation. The shape and color of the detection mark are not limited as long as they can be detected by a detector (sensor). In terms of shape,
As shown in Fig. 2, a single-line stripe can be used, or as shown in Fig. 3, single-line and double-line stripes can be mixed and used, and the thermal transfer sheet does not extend over the entire width of the thermal transfer sheet. Is mentioned. However, since the detection mark indicates the start position of the thermal transfer image formation, the detection mark is formed for each length corresponding to one section, that is, the dye layer and the thermal transferable protective layer provided in the frame order. It is possible to form the detection marks at all the head positions of the above, or to form the detection marks only in the first section of the frame sequential unit or only in a certain layer.

The color of the detection mark may be any color as long as it can be detected by the detector. For example, in the case of a light transmission type detector, silver or black, which has a high concealing property, can be used. Further, in the case of a light reflection type detector, a color tone of highly reflective metallic luster and the like can be mentioned. The detection mark is formed by a known printing method such as gravure printing or offset printing, hot stamping with a transfer foil of vapor deposition film, or sticking a colored film with an adhesive or a vapor deposition film on the back surface. However, it is not particularly limited.

[0039]

EXAMPLES Next, the present invention will be described more specifically with reference to examples. In the text, “part” or “%” is based on weight unless otherwise specified. Example 1 An untreated polyethylene terephthalate (PET) film (Dia foil K880 manufactured by Mitsubishi Kagaku Polyester Film Co., Ltd.) having a thickness of 6 μm was dried with 0.2 g of a primer layer composition liquid for a heat resistant slipping layer having the following composition. / m ² of coating and drying so that the coating amount, the heat-resistant lubricating layer composition solution a below the surface of the primer layer dried at 1.0 g /
After coating and drying so as to be m ² , heat treatment was carried out at 60 ° C. for 5 days to form a heat resistant slipping layer.

[0040] <Primer layer composition liquid for heat resistant slipping layer>   Polyester resin 10.0 parts (Nichigo Polyester LP-035; manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)   Methyl ethyl ketone 90.0 parts

[0041] <Composition liquid A for heat resistant slipping layer>   Polyvinyl butyral resin 13.6 parts (S-REC BX-1, Sekisui Chemical Co., Ltd.)   Polyisocyanate curing agent 0.6 part (Takenate D218; Takeda Pharmaceutical Co., Ltd.)   Phosphate ester (Prysurf A208S; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.8 part   Methyl ethyl ketone 42.5 parts   Toluene 42.5 parts

Next, on the surface opposite to the heat-resistant slipping layer, the following composition liquid A for protective layer was applied in an arrangement as shown in FIG. 4 so as to be 1.0 g / m ² when dried. Then, a protective layer is formed by drying, and the composition liquid A for an easy-adhesion layer is dried to 0.2 g / m ² on the entire surface of the protective layer and the substrate on which the protective layer is not provided. And then dried to form an easy-adhesion layer. After that, in the arrangement as shown in FIG. 4, the dye layer composition liquid A described below was applied onto the easy-adhesion layer so as to be 0.8 g / m ² when dried, and dried. A dye layer is provided, and an adhesive layer composition liquid having the following composition is dried at 1.5 g / m ² in an area where the dye layer is provided and the protective layer is provided below the easily adhesive layer. Was coated and dried to form an adhesive layer, and the thermal transfer sheet of Example 1 was obtained.

[0043] <Composition liquid A for protective layer>   Acrylic resin (Dianal BR-83, Mitsubishi Rayon Co., Ltd.) 50 parts   25 parts of methyl ethyl ketone   25 parts of toluene

[0044] <Composition liquid A for easy adhesion layer>   Polyester resin (Byron 240; manufactured by Toyobo Co., Ltd.) 4.4 parts   Methyl ethyl ketone 45 parts   45 parts of toluene

[0045] <Dye layer composition liquid A>   CI Solvent Blue 22 5.5 Department   Polyvinyl acetal resin 3.0 parts (S-REC KS-5; Sekisui Chemical Co., Ltd.)   Methyl ethyl ketone 22.5 parts   Toluene 68.2 parts

[0046] <Composition liquid for adhesive layer>   Polyester resin (Byron 700; manufactured by Toyobo Co., Ltd.) 69.6 parts   17.4 parts of acrylic copolymer reactively bonded with a reactive ultraviolet absorber (UVA635L, manufactured by BASF Japan Ltd.)   25 parts of silica (Sylysia 310, manufactured by Fuji Silysia Ltd.)

Example 2 An example was carried out in the same manner as in Example 1 except that the composition liquid B for the easy-adhesion layer used in Example 1 was replaced with the composition liquid B for the easy-adhesion layer described below. A thermal transfer sheet No. 2 was prepared. <Composition liquid B for easy adhesion layer> Polyurethane resin 6 parts (Superflex 460S; manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) Water 47 parts Isopropyl alcohol 47 parts

Example 3 An example was prepared in the same manner as in Example 1 except that the composition liquid C for the easy-adhesion layer described below was used in place of the composition liquid A for the easy-adhesion layer. A thermal transfer sheet of No. 3 was produced. <Composition liquid C for easy adhesion layer> Polyurethane resin 15 parts (Nipporan 5120; manufactured by Nippon Polyurethane Industry Co., Ltd.) Coronate HX 1.2 parts Methyl ethyl ketone 41.9 parts Toluene 41.9 parts

Example 4 The procedure of Example 1 was repeated, except that the composition liquid A for easy-adhesion layer used in Example 1 was applied so that the dry coating amount was 0.1 g / m ² . A thermal transfer sheet of Example 4 was produced.

Example 5 The procedure of Example 1 was repeated, except that the composition liquid A for the easy-adhesion layer used in Example 1 was applied so that the dry coating amount was 0.4 g / m ² . A thermal transfer sheet of Example 5 was produced.

(Example 6) In the same manner as in Example 1 except that the following composition liquid B for heat resistant slipping layer was used in place of the composition liquid A for heat resistant slipping layer used in Example 1, A thermal transfer sheet of Example 6 was produced. <Heat resistant slipping layer composition liquid B> Polyamideimide resin 4.4 parts (HR-15ET; manufactured by Toyobo Co., Ltd.) Polyamideimide silicone resin 4.4 parts (HR-14ET; manufactured by Toyobo Co., Ltd.) Zinc Stearyl phosphate (LBT1830, manufactured by Sakai Chemical Industry Co., Ltd.) 0.9 part Polyester resin (Vylon 220; manufactured by Toyobo Co., Ltd.) 0.3 part Toluene 45 parts Ethanol 45 parts

Example 7 In the same manner as in Example 2 except that the composition liquid B for heat resistant slipping layer was used instead of the composition liquid A for heat resistant slipping layer used in Example 2. A thermal transfer sheet of Example 7 was produced.

(Example 8) In the same manner as in Example 3 except that the composition liquid B for heat resistant slipping layer described above was used in place of the composition liquid A for heat resistant slipping layer used in Example 3, A thermal transfer sheet of Example 8 was produced.

Example 9 The procedure of Example 9 was repeated except that the following dye layer composition liquid B was used in place of the dye layer composition liquid A used in Example 1. A thermal transfer sheet was produced. <Dye Layer Composition Liquid B> Kayaset Blue 714 5.5 parts Polyvinyl acetal resin 3.0 parts (ESREC KS-5; manufactured by Sekisui Chemical Co., Ltd.) Methyl ethyl ketone 45.5 parts Toluene 45.5 parts

Example 10 The procedure of Example 10 was repeated except that the dye layer composition liquid A used in Example 2 was replaced with the dye layer composition liquid B described above. A thermal transfer sheet was produced.

Example 11 The procedure of Example 11 was repeated except that the dye layer composition liquid A used in Example 3 was replaced with the dye layer composition liquid B described above. A thermal transfer sheet was produced.

Example 12 The procedure of Example 12 was repeated in the same manner as in Example 1 except that the following dye layer composition liquid C was used in place of the dye layer composition liquid A used in Example 1. A thermal transfer sheet was produced. <Dye layer composition liquid C> CI Solvent Blue 22 5.5 parts Phenoxy resin 3.0 parts Methyl ethyl ketone 45.5 parts Toluene 45.5 parts

(Example 13) The thickness used in Example 1 was 6μ.
In the same manner as in Example 1 except that an untreated PET film (diamond foil K880 manufactured by Mitsubishi Kagaku Polyester Film Co., Ltd.) having a thickness of 4.5 μm was used instead of the untreated PET film of Example Thirteen thermal transfer sheets were produced.

(Example 14) The thickness used in Example 1 was 6μ.
Example 6 was repeated in the same manner as in Example 1 except that an untreated polyethylene naphthalate (PEN) film having a thickness of 6 μm (manufactured by Teijin Ltd., Teonex) was used instead of the untreated PET film of m. A thermal transfer sheet was produced.

(Example 15) The thickness used in Example 1 was 6μ.
The thermal transfer of Example 15 was performed in the same manner as in Example 1 except that an untreated polyphenylene sulfide (PPS) film having a thickness of 6 μm (Toray Industries, Inc., Torelina) was used in place of the m untreated PET film. A sheet was prepared.

Example 16 An example was prepared in the same manner as in Example 1 except that the following easy-adhesion layer composition liquid D was used in place of the easy-adhesion layer composition liquid A used in Example 1. Sixteen thermal transfer sheets were prepared. <Composition liquid D for easy adhesion layer> Polyvinylpyrrolidone resin (K-90, manufactured by ISP Co., Ltd.) 10 parts Methyl ethyl ketone 45 parts Isopropyl alcohol 45 parts

Example 17 An example was prepared in the same manner as in Example 1 except that the composition liquid E for the easy-adhesion layer used in Example 1 was replaced with the composition liquid E for the easy-adhesion layer described below. 17 thermal transfer sheets were produced. <Composition Liquid E for Easy Adhesion Layer> Polyvinylpyrrolidone resin (K-90, manufactured by ISP Co., Ltd.) 10 parts Silica sol 10 parts (30% isopropyl alcohol dispersion (manufactured by Nissan Chemical Industries, Ltd.) Methyl ethyl ketone 45 parts Isopropyl alcohol 45 parts

(Example 18) An example was prepared in the same manner as in Example 1 except that the composition liquid F for the easy-adhesion layer used in Example 1 was replaced with the composition liquid F for the easy-adhesion layer described below. Eighteen thermal transfer sheets were prepared. <Composition liquid F for easy-adhesion layer> Polyvinylpyrrolidone resin (K-90, manufactured by ISP Co., Ltd.) 10 parts Silica sol 10 parts (30% isopropyl alcohol dispersion (manufactured by Nissan Chemical Industries, Ltd.) Benzotriazole-based UV absorber 1 Part (TINUVIN900, manufactured by Ciba Geigy) Methyl ethyl ketone 45 parts Isopropyl alcohol 45 parts

Example 19 An example was prepared in the same manner as in Example 1 except that the composition liquid A for the easy-adhesion layer used in Example 1 was replaced with the composition liquid G for the easy-adhesion layer described below. Nineteen thermal transfer sheets were produced. <Composition liquid G for easy adhesion layer> Vinylpyrrolidone-vinyl acetate copolymer 10 parts Methyl ethyl ketone 45 parts Isopropyl alcohol 45 parts

Example 20 An example was prepared in the same manner as in Example 1 except that the composition liquid A for the easy-adhesion layer used in Example 1 was replaced with the composition liquid H for the easy-adhesion layer described below. Twenty thermal transfer sheets were prepared. <Composition liquid H for easy adhesion layer> Polyvinylpyrrolidone resin (K-90, manufactured by ISP Co., Ltd.) 10 parts Polyester resin (Vylon 220, manufactured by Toyobo Co., Ltd.) 1 part Methyl ethyl ketone 45 parts Isopropyl alcohol 45 parts

Comparative Example 1 A thermal transfer sheet of Comparative Example 1 was obtained in the same manner as in Example 1 except that the composition liquid A for the easy-adhesion layer was not applied to an untreated polyethylene terephthalate (PET) film having a thickness of 6 μm. .

Comparative Example 2 Polyethylene terephthalate (PET) film having a thickness of 6 μm and subjected to easy adhesion treatment (manufactured by Mitsubishi Kagaku Polyester Film Co., Ltd., Diamond foil K2)
03E) was used, and a thermal transfer sheet of Comparative Example 2 was obtained in the same manner as in Example 1 except that the composition liquid A for the easily adhesive layer was not applied.

Comparative Example 3 Example 1 was repeated except that a corona-treated polyethylene terephthalate (PET) film having a thickness of 6 μm was used and the composition liquid A for the easy-adhesion layer was not applied.
A thermal transfer sheet of Comparative Example 3 was obtained in the same manner as in.

Comparative Example 4 Example 1 was repeated except that a plasma-treated polyethylene terephthalate (PET) film having a thickness of 6 μm was used and the composition liquid A for the easy-adhesion layer was not applied.
A thermal transfer sheet of Comparative Example 4 was obtained in the same manner as in.

(Comparative Example 5) Composition liquid A for easy-adhesion layer was formed on the entire surface of the base material opposite to the heat-resistant slip layer of the untreated polyethylene terephthalate (PET) film having a thickness of 6 μm.
Is coated and dried so that the dry weight is 0.2 g / m ² , and
An easy-adhesion layer is formed, and the protective layer composition liquid A is applied and dried on the easy-adhesion layer so that the composition liquid A for the protective layer is 1.0 g / m ² when dried. Further, in the arrangement as shown in FIG. 4, the dye layer composition liquid A is applied on the easy-adhesion layer so as to be 0.8 g / m ² when dried, and dried. A dye layer was provided to obtain a thermal transfer sheet of Comparative Example 5.

(Comparative Example 6) A polyethylene terephthalate (PET) film having a thickness of 6 μm and treated for easy adhesion (manufactured by Mitsubishi Kagaku Polyester Film Co., Ltd., Diamond foil K2)
03E), the primer layer composition liquid for a heat resistant slipping layer used in Example 1 was applied and dried to give a coating amount of 0.2 g / m ² when dried, and Example 1 was applied to the surface of the primer layer. 1.0 g of the composition liquid A for heat-resistant slipping layer used in
After coating and drying so as to be m ² , heat treatment was carried out at 60 ° C. for 5 days to form a heat resistant slipping layer. Next, using the composition liquid A for dye layer in the arrangement as shown in FIG. 5 on the opposite surface (the surface for easy adhesion treatment) on which the heat resistant slipping layer is provided,
To a dry time of 0.8 g / m ^2, coated and dried to provide a dye layer, and as using a release layer composition solution having the following, a dry time of 0.8 g / m ^2, A release layer is provided by coating and drying, and the composition liquid A for a protective layer is further applied and dried on the release layer so as to be 1.0 g / m ² when dried to form a protective layer. Further, the adhesive layer composition liquid used in Example 1 was applied and dried on the protective layer so as to have a dry amount of 1.5 g / m ² to form an adhesive layer, and the thermal transfer sheet of Comparative Example 6 was formed. Got

[0072] <Release layer composition liquid>   Silicone modified acrylic resin 45.7 parts (Celltop 226, manufactured by Daicel Chemical Industries, Ltd.)   Aluminum catalyst 8.5 parts (Celltop CAT-A, manufactured by Daicel Chemical Industries, Ltd.)   Methyl ethyl ketone 22.9 parts   Toluene 22.9 parts

Printing was performed under the following conditions. Printing machine: Digital color printer P-200, manufactured by Olympus Corp. Printing paper; Standard color printing paper thermal transfer sheet for digital color printer P-200; Thermal transfer sheet printing produced in Examples 1-20 and Comparative Examples 1-6 Pattern: gradation pattern Furthermore, the protective layer was transferred using the thermal transfer sheet of each example so as to cover the printed portion of the printed product, using the same printer as that for forming the image. At that time, the dye transferability (whether there is abnormal transfer, whether there is uneven transfer, etc.) on the printed matter,
The transferability of the protective layer (presence or absence of abnormal transfer, presence or absence of sticking, etc.) was evaluated. Further, the glossiness of the image portion with the protective layer transferred onto the printed matter was measured. In addition, a primer layer and a heat resistant slipping layer on the back side of the thermal transfer sheet of each example are provided,
On the opposite side, with no protective layer or dye layer provided,
Rolled with a winding length of 240m, 50 ℃, 85%
After storing in an RH environment for 2 days, it was rewound and the occurrence of blocking was examined. Further, the printed matter on which the protective layer was transferred was evaluated for plasticizer resistance and scratch resistance.

(Blocking resistance) The occurrence of blocking was visually observed and evaluated according to the following criteria. ○: Transfer of the layer to the contact surface is not observed, and the film can be smoothly rewound. X: The layer is transferred to the contact surface, or the film cannot be smoothly rewound due to adhesion.

(Dye Transferability) The dye transferability (whether there is abnormal transfer, whether there is transfer unevenness, etc.) on the printed matter is visually observed,
The following criteria evaluated. B: Good, with no defects in dye transferability such as abnormal transfer and transfer unevenness. ×: Abnormal transfer or uneven transfer, and defective.

(Protective Layer Transferability) The transferability of the protective layer, that is, the presence or absence of abnormal transfer of the protective layer, the presence or absence of sticking, etc. were visually observed and evaluated according to the following criteria. ⊚: No abnormal transfer or sticking, 0.0 compared to conventional
Transfer is possible with low energy of 5 mJ / line or more. ○: No abnormal transfer or sticking. Δ: Partially abnormal transfer or sticking is present, or there is no abnormal transfer, but the peeling interface is not smooth. ×: Abnormal transfer or sticking occurs, and transfer is impossible.

(Glossiness) The specular glossiness (GS (45 °)) of the surface of the protective layer was measured by Nippon Denshoku Industries Co., Ltd. in the highest density portion of the prints with the protective layer obtained in each of the above examples. , G
Using lossMeter VG2000, JISZ
It was measured according to -8741-1983. The gloss level was evaluated according to the following criteria. ⊚: Compared with the glossiness of Comparative Example 6, the glossiness exceeds 110%. ◯: Compared with the glossiness of Comparative Example 6, the range is 100 to 110%. X: Less than 100% as compared with the glossiness of Comparative Example 6. -: Measurement is impossible because the protective layer does not transfer normally. Comparative Example 1 in which dye transfer cannot be performed normally,
Regarding Nos. 3 and 4, the glossiness was measured by transferring the protective layer of each Comparative Example to the dye transfer product of Comparative Example 6.

(Plasticizer resistance) A soft vinyl chloride sheet (Altron) was placed on the image forming surface of the printed matter, and the load was 40 g / m ^2.
It is left at 50 ° C. for 48 hours in the applied state. After that,
The printed matter and the vinyl chloride sheet were peeled off, and the degree of transfer of the dye in the printed matter to the vinyl chloride sheet was visually observed and evaluated according to the following criteria. ⊚: There is no migration of dye. ◯: There is almost no migration of dye. Δ: Transfer of dye can be confirmed to some extent. X: The dye is transferred to almost the entire surface.

(Scratch resistance) The printed matter was subjected to a scratch resistance tester (Shimadzu dynamic ultra-fine hardness meter DHU-201S).
An abrasion test was carried out at 200 rotations, the state of the image of the printed matter was visually observed, and evaluated according to the following criteria. A: The image is not affected at all. ◯: The image begins to be affected by wear, but it is hardly noticeable. Δ: Some wear is confirmed. X: Worn considerably.

The above evaluation and measurement results are shown in Tables 1 and 2.

[Table 1]

[0081]

[Table 2]

[0082]

As described above, the present invention provides a thermal transfer sheet in which a dye layer of at least one color and a thermal transferable protective layer are provided on one surface of a substrate in a surface sequential manner. Partially provided with a protective layer, and then provided with an easy-adhesion layer on the entire surface of the protective layer and the substrate, and then on the easy-adhesion layer and in a region where the protective layer is not located below Is provided. Further, it is preferable to provide an adhesive layer on the above-mentioned easy-adhesion layer and in a region where the protective layer is located below. It is preferable to provide a detection mark between the dye layer and the heat transferable protective layer, or between the dye layers of a plurality of colors, or both.

By using such a heat transfer sheet, the easy adhesion layer is post-coated using a plain base material without using a base material which has been subjected to an easy adhesion treatment which is very expensive in manufacturing the heat transfer sheet. Therefore, the cost can be reduced. In addition, base materials for which easy adhesion treatment is difficult,
It is possible to use base materials that do not have an easy-adhesion treatment grade, and various base materials can be used depending on the application.
The range of substrates that can be used is expanded. Furthermore, since the release layer is not required, damage to the substrate due to heat during drying can be mitigated, and the thermal transfer sheet can be thinned.

According to the specifications of the conventional protective layer heat transfer sheet, since the peeling occurs at the interface between the gravure-coated protective layer and the release layer, the smoothness of the interface is poor. However, in the present invention, since the film is directly peeled from the surface of the substrate, the surface smoothness as in the case of the ferro-treatment can be improved, and the glossiness of the printed matter on which the protective layer is transferred can be increased. Further, when the conventional easy-adhesion-treated raw fabric was used, blocking sometimes occurred when wound up after coating the back layer, but in the present invention, the opposite surface is treated when the back layer is coated. Since there is no blocking, it is possible to prevent blocking.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing one embodiment of a thermal transfer sheet of the present invention.

FIG. 2 is a schematic cross-sectional view showing another embodiment of the thermal transfer sheet of the present invention.

FIG. 3 is a schematic cross-sectional view showing another embodiment of the thermal transfer sheet of the present invention.

FIG. 4 is a schematic sectional view showing an example of a thermal transfer sheet of the present invention.

FIG. 5 is a schematic sectional view showing an example of a conventional thermal transfer sheet.

[Explanation of symbols] 1 Thermal transfer sheet 2 base materials 3 Easy adhesion layer 4 protective layer 5 Dye layer 6 Thermal transfer protective layer 7 Adhesive layer 8 detection mark 9 units 10 Heat resistant slipping layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenichi Hirota             1-1-1, Ichigaya-Kagacho, Shinjuku-ku, Tokyo             Dai Nippon Printing Co., Ltd. F term (reference) 2H111 AA01 AA08 AA16 AA27 AA52                       BA09 BA11 BA14 BB14 BB15

Claims (4)

[Claims] 1. A thermal transfer sheet comprising a dye layer of at least one color and a thermal transferable protective layer provided on one surface of a base material in a surface sequential manner, wherein a protective layer is partially provided on one surface of the base material. After that, an easy-adhesion layer is provided on the entire surface of the protective layer and the base material, and then a dye layer is provided on the easy-adhesion layer and in a region where the protective layer is not located below. Thermal transfer sheet. 2. The easy-adhesion layer contains a homopolymer of N-vinylpyrrolidone or a copolymer of N-vinylpyrrolidone and another component.
The thermal transfer sheet described in. 3. The adhesive layer is provided in the region where the protective layer is located below and above the easy-adhesion layer. Thermal transfer sheet. 4. The detection mark is provided between the dye layer and the thermal transferable protective layer, between the dye layers of a plurality of colors, or both of them. The thermal transfer sheet described in one.