JPH09202058A - Thermal transfer sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an excellent peeling property to be stably shown by providing at least, a single color on one of the faces of a base material sheet and adding at least, a sublimable dye, a silicone graft polymer and a polysiloxane compound to the dye layer. SOLUTION: A thermal ink transfer sheet consists of a dye layer 3 and a medium to which an ink is transferred stacked on one of the faces of a base material sheet 2, from the side of which a sublimable dye is thermally transferred to the medium. In this case, the dye layer 3 contains at least, the sublimable dye, a silicone graft polymer and a polysiloxane compound. In addition, the dye layer 3 contains the same polymer as constituting the silicone graft polymer. Further, the degree of polymerization of a siloxane chain of the polysiloxane compound is set to the range of 3-48, and the polysiloxane compound has the functional group of either NH2 or NHR (R is an alkyl group) on, at least, one of the terminals of or halfway through the chain.

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, and more particularly, to a transfer sheet which is provided with a dye layer on a base sheet and which is heated from the side of the base sheet in a state where the dye layer and the transfer sheet are superposed. The present invention relates to a thermal transfer sheet that transfers a sublimable dye onto a sheet.

[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 object to be transferred. As the thermal transfer method, a thermal sublimation transfer method and a thermal melt transfer method are widely used.

Among them, in the thermal sublimation transfer system, a thermal transfer sheet in which a dye layer in which a sublimable dye used as a coloring material is melted or dispersed in a binder is carried on a base material sheet is superposed on an object to be transferred, and a thermal head is used. A dye contained in the sublimable dye layer on the thermal transfer sheet is transferred to a transfer target by applying energy corresponding to image information to a heating device such as the above to form an image. This thermal sublimation transfer method is excellent in the formation of a gradation image because the transfer amount of the dye can be controlled in dot units by the amount of energy applied to the thermal transfer sheet.

One of the important characteristics required for the thermal transfer sheet of the thermal sublimation transfer system is the releasability from the transferred material. That is, as described above, the thermal transfer sheet and the transfer target are superposed and heated. Therefore, it is important for the transfer to be performed smoothly that the releasability between the two is good after the transfer. Further, since the thermal transfer sheet and the transfer target are usually conveyed in a state of being overlapped with each other before and after transfer, it is important that the thermal transfer sheet has releasability in order to prevent blocking of both. Therefore, a thermal transfer sheet in which a release agent such as silicone is added to the dye layer is used.

[0005]

However, in such a thermal transfer sheet, the compatibility between the release agent and the binder is not good, and the release agent component may separate and come out on the surface of the dye layer, which is stable. It does not have the releasability described above.

In order to solve this drawback, a thermal transfer sheet has been developed which uses, as a binder, a releasable graft polymer obtained by graft-copolymerizing a releasable compound with the polymer (JP-A-2-141289, etc.). ).

However, as the range of use of the thermal transfer sheet of the thermal sublimation transfer system is expanded, the kinds of the transferred material are also increased, especially when an image or the like is directly formed on the transferred material having no dye receiving layer, Depending on the material of the material to be transferred, even if the above-mentioned thermal transfer sheet is used, the phenomenon of sticking to the material to be transferred occurs, which hinders smooth thermal transfer.

The present invention has been made in view of the above circumstances, and is not affected by the material of the transferred material,
It is an object of the present invention to provide a thermal transfer sheet capable of stably exhibiting excellent releasability.

[0009]

In order to achieve such an object, the thermal transfer sheet of the present invention is provided with a dye layer of at least one color on one surface of a substrate sheet, and the dye layer is at least sublimable. It was configured to contain a dye, a silicon graft polymer and a polysiloxane compound.

Further, the dye layer is configured to further contain the same polymer as that constituting the silicon graft polymer.

The polysiloxane compound has a siloxane chain polymerization degree in the range of 3 to 48.

Further, the polysiloxane compound has at least one of the ends or in the middle thereof -NH ₂ , -NHR.
(R is an alkyl group), an epoxy group, a hydroxyl group, an alkyl group, and a phenyl group.

Further, the dye layer is configured to contain the polysiloxane compound in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the polysiloxane chain component constituting the silicon graft polymer.

Further, the dye layer has a two-layer structure.

Further, at least one of a heat-fusible ink layer and a transferable protective laminate is provided in the dye layer on the side of the dye layer forming surface of the substrate sheet in the plane order.

In such a thermal transfer sheet of the present invention, the dye layer contains a sublimable dye together with a silicon graft polymer and a polysiloxane compound, and the polysiloxane compound has a high compatibility with the silicon graft polymer and has a releasing action. Since it is excellent, it cooperates with the silicon graft polymer to further enhance the releasability of the dye layer.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The thermal transfer sheet of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the thermal transfer sheet of the present invention.
It is a schematic sectional drawing which shows. In FIG. 1, the thermal transfer sheet
1 has a dye layer 3 on one surface of a base sheet 2, and
A back layer 4 is provided on the other surface of the board 2. Book below
The structure of the thermal transfer sheet 1 of the invention will be described.Base sheet Conventionally, as the base material sheet 2 constituting the thermal transfer sheet 1,
It is possible to use the base material sheet used for the thermal transfer sheet of
it can. Specific examples of preferable substrate sheets include glassine paper,
Condenser paper, thin paper such as paraffin paper, polyethylene
Terephthalate, polyethylene naphthalate, polybu
Tylene terephthalate, polyphenylene sulfide,
Heat resistance of polyetherketone, polyethersulfone, etc.
High Polyester, Polypropylene, Polycarbonate
G, cellulose acetate, polyethylene derivatives, polychlorination
Vinyl, polyvinylidene chloride, polystyrene, polyamid
, Polyimide, polymethylpentene, ionomer, etc.
Stretched or unstretched film of plastic,
The thing which laminated | stacked these materials is mentioned. This base sheet
The thickness of 2 is a material so that the strength and heat resistance are appropriate.
Although it can be appropriately selected depending on the charge, it is usually 1 to 1
Those having a diameter of about 00 μm are preferably used. Dye layer The dye layer 3 constituting the thermal transfer sheet 1 is at least sublimated.
Dye, silicone graft polymer and polysiloxane
It is characterized by containing a compound.

As the sublimable dye to be used, the sublimable dye used in the heat transfer sheet of the conventionally known heat-sensitive sublimation transfer system can be used and is not particularly limited. Specifically, for example, as the yellow dye, Holon Brilliant Yellow S-6GL, PTY-52, Macrolex Yellow S-6G and the like can be mentioned, and as the red dye, MS Red, Macrolex Red Violet R, Celes Red 7B, Sax. Marron Red HBSL, SK Rubin SEGL
Further, as the blue dye, Kayaset Blue 714, Waxolin Blue AP-FW, Holon Brilliant Blue SR, MS Blue 100, Daito Blue No. 1 and the like can be mentioned.

The silicon graft polymer constituting the dye layer 3 is a polymer main chain to which a polysiloxane chain is graft-bonded, and a conventionally known silicon graft polymer can be used.

The silicon graft polymer can be synthesized by various methods. For example, after forming a polymer main chain, a functional group existing in the polymer main chain is added to the functional group.
Examples thereof include a method of reacting a polysiloxane compound having a functional group that reacts with this.

Examples of the polymer forming the silicon graft polymer include polyvinyl acetal resin, acrylic resin, vinyl resin, polyester resin, polyurethane resin, polyamide resin, and cellulose resin whose main chain is a polymer. Among them, a polymer whose main chain is a polyvinyl acetal resin is particularly preferable from the viewpoint of affinity with the sublimable dye. The term "polyvinyl acetal" in this case should be interpreted in a broad sense, and in the present invention, the case where the acetal part of the polyvinyl acetal is formaldehyde is called polyvinyl formal, and the case where the acetal part is acetaldehyde is called polyvinyl acetal, Furthermore, the case where the acetal part is butyraldehyde is called polyvinyl butyral. Therefore, when simply referred to as polyvinyl acetal, it is meant to include all of these acetals. It is preferable that the above-mentioned polymers have a degree of polymerization of 500 to 5000, preferably 1000 to 3000.

The polysiloxane compound grafted to the polymer main chain is represented by the following general formula (I).

[0024]

Embedded image In the above formula (I), R ¹ and R ² are an alkyl group such as a methyl group or an aromatic group such as a phenyl group, and are —OH or —NH.
_It may contain functional groups such as ₂ , -NH-, a carboxyl group, and an epoxy group. R ¹ and R ² may be the same or different, and the polysiloxane chain polymerization degree m is preferably an integer in the range of 3 to 48. In addition, the above formula (I)
The polysiloxane compound represented by has a functional group at least at one end or in the middle. When the functional group of such a polysiloxane compound is X and the functional group of the above polymer is Y, the following Table 1 is obtained.
The silicon graft polymer can be synthesized by the combination of the functional groups X and Y shown in (3). However, the relationship between the functional groups X and Y may be reversed, and a combination of two or more kinds is also possible. This functional group is merely an example, and the present invention is not limited to this.

[0025]

[Table 1] The silicone graft polymer used in the present invention has a degree of polymerization of 500 to 5000, preferably 1000 to 3000, and the proportion of polysiloxane chains in the silicone graft polymer is 0.1 to 40% by weight, preferably It is in the range of 1 to 10% by weight.

The polysiloxane compound contained in the dye layer 3 together with the above-mentioned sublimable dye and silicon graft polymer is represented by the following general formula (II).

[0027]

Embedded image In the above formula (II), R ³ and R ⁴ are an alkyl group such as a methyl group or an aromatic group such as a phenyl group, and are —OH or —NH.
_It may contain functional groups such as ₂ , -NH-, a carboxyl group, and an epoxy group. R ³ and R ⁴ may be the same or different, and the polysiloxane chain polymerization degree n is preferably an integer in the range of 3 to 48. Also, the above formula (II)
The polysiloxane compound represented by has a functional group at least at one end or in the middle. Examples of this terminal functional group include the functional group X as shown in Table 1 above.

The polysiloxane compound represented by the above formula (II) is contained in the dye layer 3 together with the silicon graft polymer, and this content is 100 parts by weight of the polysiloxane chain component constituting the silicon graft polymer. On the other hand, the proportion is preferably 0.1 to 50 parts by weight, preferably 1 to 20 parts by weight. When the content of the polysiloxane compound is less than 0.1 parts by weight, the thermal transfer sheet of the present invention has insufficient releasability and may cause thermal fusion during thermal transfer depending on the material of the transferred material. There is. Further, when the content of the polysiloxane compound exceeds 50 parts by weight, the polysiloxane compound may separate and float on the surface of the dye layer, which makes it difficult for the thermal transfer sheet to exhibit stable releasability.

In the thermal transfer sheet 1 of the present invention, in addition to the sublimable dye, the silicon graft polymer and the polysiloxane compound as described above, the dye layer 3 contains a polymer which is the same as the polymer constituting the above silicon graft polymer. It may be contained as a component. By thus containing the polymer in addition to the silicon graft polymer as the binder in the dye layer 3, the affinity between the sublimable dye and the binder is further improved. The content of the polymer in the binder is 100 g of the silicon graft polymer.
50 to 2000 parts by weight, preferably 10 parts by weight
The range is from 0 to 1500 parts by weight.

The dye layer 3 may contain wax in addition to the sublimable dye, silicon graft polymer and polysiloxane compound as described above. As the wax used, for example, microcrystalline wax, carnauba wax, paraffin wax, Fischer-Tropsch wax, various low molecular weight polyethylene, wood wax, beeswax, whale wax, ivowa wax,
Wool wax, shellac wax, candelilla wax,
Petrolactam, partially modified wax, fatty acid ester,
Waxes such as fatty acid amides, silicone wax,
Examples thereof include silicone resin, fluororesin, acrylic resin, cellulose resin, vinyl chloride-vinyl acetate copolymer, and nitrified cotton. Such a wax can be contained in the dye layer in an amount of 0.1 to 10% by weight, preferably 1 to 3% by weight.

Further, the dye layer 3 comprises the above-mentioned sublimable dye,
In addition to the silicon graft polymer, the polysiloxane compound, and the wax and polymer added as necessary, various known additives can be contained. For example, by adding organic fine powder or inorganic fine powder to the dye layer 3 in the range of 0.1 to 10% by weight, the dye layer 3
It is possible to improve the suitability for forming a coating film when forming a film, and also to improve the releasability during thermal transfer.

As such an organic fine powder, for example,
Polyolefin resin such as polyethylene and polypropylene, polyamide resin such as fluororesin and nylon resin, urethane resin, styrene / acrylic crosslinked resin, phenol resin, urea resin, melamine resin, polyimide resin,
Fine powder such as benzoguanamine resin is preferably used,
Polyethylene fine powder is particularly preferable.

As the inorganic fine powder, fine powders of calcium carbonate, silica, clay, talc, titanium oxide, magnesium hydroxide, zinc oxide and the like are preferably used.

The dye layer 3 is formed, for example, by gravure coating an ink prepared by dissolving or dispersing the above-mentioned sublimable dye, silicon graft polymer, polysiloxane compound and other additives in a suitable solvent. It can be performed by coating and drying by a known means.
The thickness of the dye layer 3 is about 0.2 to 5 μm, preferably 0.
The dye layer 3 may have a sublimable dye content of 5 to 90% by weight, preferably 10 to 70%.
% By weight.

The dye layer 3 of the above-mentioned thermal transfer sheet 1 is formed on the base material sheet 2 in a single layer structure, but in the thermal transfer sheet of the present invention, the dye layer may have a two-layer structure. . In this case, each layer constituting the dye layer can be a layer containing at least a sublimable dye, a silicon graft polymer and a polysiloxane compound. Alternatively, among the layers constituting the dye layer, only the layer located at the outermost surface contains at least the sublimable dye, the silicon graft polymer and the polysiloxane compound, and the other layers do not contain, for example, the silicon graft polymer. It can also be a layer. The total thickness of the dye layer having such a two-layer structure is about 0.2 to 5 μm, preferably 0.4 to 2 μm.
The thickness of one layer constituting the dye layer is preferably in the range of 0.4 to 2 μm. The sublimable dye contained in the entire dye layer is 5 to 90% by weight, preferably 1
It is about 0 to 70% by weight. The back surface layer 4 provided on the back surface of the back surface base material sheet 2 is provided for the purpose of preventing thermal fusion between the heating device such as a thermal head and the base material sheet 2 and allowing smooth running. Examples of the resin used for the back surface layer 4 include cellulosic resins such as ethyl cellulose, hydroxycellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, and nitrocellulose, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal. , Vinyl-based resins such as polyvinylpyrrolidone, polymethyl methacrylate, polyethyl acrylate, polyacrylamide, acrylic resins such as acrylonitrile-styrene copolymer, polyamide resins, polyvinyltoluene resins, coumarone-indene resins,
A single or a mixture of natural or synthetic resins such as polyester resins, polyurethane resins, silicone-modified or fluorine-modified urethane, etc. may be used. In order to further improve the heat resistance of the back surface layer 4, it is possible to use a resin having a hydroxyl functional group among the above-mentioned resins and use a polyisocyanate or the like as a crosslinking agent to form a crosslinked resin layer. preferable.

Further, in order to provide slidability with the thermal head, a solid or liquid release agent or lubricant may be added to the back surface layer 4 so as to have heat resistant slipping property. Examples of the release agent or lubricant include various waxes such as polyethylene wax and paraffin wax, higher aliphatic alcohols, organopolysiloxanes, anionic surfactants,
Use of cationic surfactants, amphoteric surfactants, nonionic surfactants, fluorine surfactants, organic carboxylic acids and derivatives thereof, fluorine resins, silicone resins, fine particles of inorganic compounds such as talc and silica, etc. be able to. The amount of the lubricant contained in the back surface layer 4 is 5 to 50% by weight, preferably about 10 to 30% by weight.

The thickness of the back layer 4 is 0.1-10.
It can be about μm, preferably about 0.5 to 5 μm.

FIG. 2 is a plan view showing another embodiment of the thermal transfer sheet of the present invention. In FIG. 2, the thermal transfer sheet 11
On the substrate sheet (not shown), yellow, magenta,
Each dye layer 13 containing a sublimable dye of each hue of cyan
The dye layer 13, which is composed of Y, 13M, and 13C, the heat-fusible ink layer 14, and the transferable protective laminate 15 are formed in a frame order.

As the base material sheet constituting the thermal transfer sheet 11, the same base material sheet 2 as the heat transfer sheet 1 can be used. The dye layer 13 can be formed in the same manner as the dye layer 3 of the thermal transfer sheet 1 described above, and the dye layers 13Y, 13M and 13C of the three colors of the dye layer 13 are formed.
At least one of them can be a two-layer structure as described above. The heat-melting ink layer 14 of the heat-melting ink layer heat transfer sheet 11 may be a conventionally known heat-melting ink layer and is not particularly limited. As an example of the heat-fusible ink layer 14, there can be mentioned one in which a peeling OP layer and a heat-fusible colored ink layer are laminated in this order from the base material sheet side.

The peeling OP layer constituting such a heat-meltable ink layer 14 is, for example, microcrystalline wax, carnauba wax, paraffin wax, Fischer-Tropsch wax, various low molecular weight polyethylene, wood wax, beeswax, whale wax, Waxes such as Ibotaro, wool wax, shellac wax, candelilla wax, petrolactam, partially modified wax, fatty acid ester, fatty acid amide, silicone wax, silicone resin, fluororesin, acrylic resin, cellulose resin, vinyl chloride-acetic acid It can be formed using a vinyl copolymer, nitrification cotton, or the like.

The peeling OP layer can be formed by applying and drying using a conventionally known means such as hot melt coating, hot lacquer coating, gravure coating, gravure reverse coating and roll coating. The thickness of the release OP layer is preferably about 0.1 to 5 μm. When the peeling OP layer has a matte tone, the peeling OP layer may contain an organic or inorganic fine powder used in the dye layer 3 described above.

The heat-meltable colored ink layer constituting the heat-meltable ink layer 14 is composed of a colorant and a vehicle, and various additives are added as necessary. As the coloring agent, among organic or inorganic pigments or dyes, those having good properties as a recording material, for example, those having a sufficient coloring density and not discoloring by light or heat are preferable. The colorant is preferably carbon black, a red pigment, a blue pigment or a yellow pigment that can transfer and print clear characters or symbols at a high concentration.

As the vehicle, a mixture of resin and wax is used. As the wax, for example, microcrystalline wax, carnauba wax, paraffin wax, Fischer-Tropsch wax,
Various low molecular weight polyethylene, wood wax, beeswax, spermaceti wax, ivota wax, wool wax, shellac wax, candelilla wax, petrolactam, partially modified wax,
Examples thereof include fatty acid ester and fatty acid amide. As the resin, acrylic resin, vinyl chloride-
And vinyl acetate copolymer. It is preferable that the colorant is contained in the range of 20 to 80% by weight with respect to these vehicles.

The formation of such a heat-fusible colored ink layer is carried out by applying and drying using a conventionally known means such as hot melt coating, hot lacquer coating, gravure coating, gravure reverse coating and roll coating. And the thickness is preferably about 0.2 to 10 μm.

A release layer may be provided between the release OP layer and the base sheet in order to improve the release property from the base sheet. This release layer can be formed using a resin such as urethane, polyvinyl alcohol, polyvinylpyrrolidone, or silicone. The transferable protective laminate 15 constituting the transferable protective laminate thermal transfer sheet 11 is
For example, (1) a protective layer and an adhesive layer laminated in this order from the substrate sheet side, (2) a protective layer, a primer layer, an ultraviolet absorbing layer and an adhesive layer laminated in this order,
(3) The protective layer, the ultraviolet absorbing layer and the adhesive layer may be laminated in this order. Each transferable protective laminate will be described below. The transferable protective laminate of (1) The protective layer constituting the transferable protective laminate 15 is mainly composed of a mixture of an acrylic resin, a wax, a vinyl chloride-vinyl acetate copolymer and a polyester resin.

The acrylic resin is excellent in transparency, can form a relatively tough coating, can impart hardness to the protective layer, and can impart durability such as scratch resistance and chemical resistance. Further, it is possible to make the film breakage during thermal transfer favorable.

The wax is contained in order to impart slipperiness to the protective layer, and the wax mentioned in the description of the peeling OP layer can be used. The amount of wax used is preferably in the range of 0.5 to 5 parts by weight per 100 parts by weight of the acrylic resin.

The vinyl chloride-vinyl acetate copolymer used together with the above-mentioned acrylic resin and wax as a component constituting the protective layer imparts flexibility to the protective layer, and the polyester resin is used during thermal transfer. The peelability of the protective layer is adjusted. The amount of vinyl chloride-vinyl acetate copolymer added is 5 to 5 per 100 parts by weight of the acrylic resin.
About 0 parts by weight, and the addition amount of the polyester resin is preferably about 0.1 to 5 parts by weight per 100 parts by weight of the acrylic resin.

Further, by adding additives such as an ultraviolet absorber, an antioxidant and an optical brightening agent to the protective layer,
It is possible to improve gloss, light resistance, weather resistance, whiteness and the like of an image or the like covered with a protective layer after being transferred to a transfer target.

The adhesive layer constituting the transferable protective laminate 15 is for improving the adhesiveness between the protective layer and the transfer-receiving material, and is, for example, acrylic resin, vinyl chloride resin, vinyl chloride- It can be formed by applying and drying a solution of a resin having a good hot-melt adhesive property such as a vinyl acetate copolymer, an acrylic-vinyl chloride-vinyl acetate copolymer, a polyester resin and a polyamide resin. When the transfer target is a card substrate whose surface is made of polyvinyl chloride resin, for example, a vinyl chloride-vinyl acetate copolymer is used as a heat-sensitive adhesive having good adhesion to the polyvinyl chloride resin and good film breakage. Polymers, acrylic-vinyl chloride-vinyl acetate copolymers, acrylic resins, polyamide resins and the like can be used. The thickness of this adhesive layer can be about 0.5 to 10 μm. Also,
By including additives such as an ultraviolet absorber, an antioxidant, and a fluorescent whitening agent in the adhesive layer, it is possible to improve gloss, light resistance, weather resistance, whiteness, etc. of an image covered by the adhesive layer. . The protective layer constituting the transferable protective laminate 15 of (2) is a layer containing an ionizing radiation curable resin as a main component and has a thickness of 1 to 10 μm.
The degree is preferred.

The ionizing radiation curable resin constituting the protective layer is a polymer or oligomer having a radical-polymerizable double bond in its structure, which is crosslinked and cured by irradiation with ionizing radiation. Photopolymerization initiator is added thereto and polymerized and cross-linked by an electron beam or an ultraviolet ray. Any conventionally known ionizing radiation curable resin can be used and is not particularly limited.

When ultraviolet irradiation is used, sensitizers such as benzoethers such as benzoin, benzoin and benzoin methyl ether, halogenated acetophenones, diacetyls and the like which generate radicals upon irradiation with ultraviolet rays are radical-polymerizable monomers. Alternatively, about 1 to 20% by weight may be added and used.

In the ionizing radiation curable resin as described above, in order to improve flexibility and adhesiveness, a cellulosic resin such as ethyl cellulose, a polyester resin, a polyurethane resin, a rosin ester resin, a ring or the like may be added, if necessary. A rubber-based resin such as a foamed rubber, an acrylic resin or the like may be mixed.

Further, although these resins have excellent transparency, they tend to form a relatively tough film, so that the film breakage when transferring the protective layer may not be sufficient. Therefore, when forming the protective layer, it is preferable to add a relatively large amount of highly transparent fine particles to the ionizing radiation curable resin. The fine particles have a particle diameter of 0.01 to 50.
Examples thereof include inorganic fine particles of about μm such as silica, alumina, calcium carbonate, talc, and clay, and organic fillers such as acrylic resin, polyester resin, melamine resin, epoxy resin, and polyethylene resin. When using fine particles such as silica and alumina as fine particles, in order to improve the compatibility with the ionizing radiation curable resin, silica,
It is possible to use a material such as alumina whose surface is treated with a silane coupling agent or the like.

Such highly transparent fine particles are preferably contained in an amount of 5 to 50 parts by weight per 100 parts by weight of the above ionizing radiation curable resin.

Further, by adding a wax, a lubricant, an ultraviolet absorber, an antioxidant and / or a fluorescent whitening agent as other additives to the protective layer, the lubricity of a transfer image covered with the protective layer, It is possible to improve gloss, light resistance, weather resistance, whiteness and the like.

As a method for forming the protective layer on the base material sheet, an ink is prepared by adding an appropriate solvent or additive to the ionizing radiation curable resin as necessary to adjust the viscosity and the like. Examples of the method include a method of forming, by coating, drying and curing on the base material sheet using a known means such as gravure coating, gravure reverse coating and roll coating.

Radiation such as ultraviolet rays or electron beams is used to cure the ionizing radiation curable resin. Curing by ionizing radiation may be performed immediately after coating, or after forming the primer layer, the ultraviolet absorbing layer and the adhesive layer. In the latter case, the primer layer can effectively prevent the ionizing radiation-curable resin ink of the protective layer which is in a soft state before curing from being mixed with the ink of the ultraviolet absorbing layer and the solvent attack.

The primer layer constituting the transferable protective laminate 15 has a function of improving the adhesiveness between the above-mentioned protective layer and the ultraviolet absorbing layer, and in the formation of the transferable protective laminate 15, ionizing radiation is prevented. It is also a layer which also serves as a barrier layer for preventing solvent attack and resin mixing between the protective layer in a very soft state before irradiation and the ultraviolet absorbing layer.

Such a primer layer is formed by applying an acrylic resin such as methyl methacrylate or ethyl methacrylate onto the protective layer using a known means such as gravure coating, gravure reverse coating or roll coating, and then drying. The thickness can be about 0.1 to 5 μm.

The ultraviolet absorbing layer constituting the transferable protective laminate 15 is a layer for improving the light resistance of an image or the like transferred to a transfer-receiving member. This ultraviolet absorbing layer is characterized by containing a resin in which a reactive ultraviolet absorbent is reactively bonded. Specifically, non-reactive ultraviolet absorbers such as salicylate-based, benzophenone-based, benzotriazole-based, substituted acrylonitrile-based, nickel chelate-based, hindered amine-based, which are conventionally known organic ultraviolet absorbers, for example, vinyl. It is possible to use those into which an addition-polymerizable double bond such as a group, an acryloyl group or a methacryloyl group, or an alcoholic hydroxyl group, an amino group, a carboxyl group, an epoxy group, an isocyanate group or the like is introduced.

The ultraviolet absorbing layer is formed by gravure coating,
It can be performed using a known means such as gravure reverse coating and roll coating. The thickness of the formed ultraviolet absorbing layer is about 0.5 to 5 μm, preferably about 1 to 2 μm.

The adhesive layer constituting the transferable protective laminate 15 can be formed in the same manner as the adhesive layer constituting the transferable protective laminate 15 described in (1) above, and therefore the description thereof is omitted here. . The transferable protective laminate of (3) The protective layer constituting the transferable protective laminate 15 is mainly composed of a mixture of polymethylmethacrylate (PMMA) and wax.

PMMA is excellent in transparency, can form a relatively tough coating, can impart hardness to the protective layer, and can impart durability such as scratch resistance and chemical resistance. Further, the film breakage at the time of transfer of the transferable protective laminate 15 to the transfer target can be made favorable.

The wax is contained in the protective layer in order to impart slipperiness to the protective layer, and the wax mentioned in the description of the peeling OP layer can be used. The amount of wax used is preferably in the range of 0.5 to 5 parts by weight per 100 parts by weight of PMMA. If the amount of wax used is less than 0.5 parts by weight, the abrasion resistance of the protective layer will be insufficient, and if it exceeds 5 parts by weight, the durability and transparency of the protective layer will be insufficient, which is not preferable.

Further, the protective layer may contain substantially transparent inorganic or organic fine particles in the range of 5 to 20% by weight based on PMMA. By including such fine particles, the film breakage at the time of transfer of the transferable protective laminate 15 can be improved, the scratch resistance of the protective layer can be further improved, and the surface gloss of the protective layer can be improved. It can be suppressed to obtain a matte surface.

Further, by adding additives such as an ultraviolet absorber, an antioxidant and a fluorescent whitening agent to the protective layer,
It is possible to improve gloss, light resistance, weather resistance, whiteness and the like of an image covered with the protective layer after being transferred.

As a method for forming the protective layer on the base material sheet, an ink is prepared by mixing PMMA and wax and adding additives as necessary, and this ink is gravure coated or gravure coated on the base material sheet. Examples of the method include coating and drying using a known means such as reverse coating or roll coating. The protective layer to be formed has a thickness of about 0.5 to 5 μm, preferably about 1 to 3 μm.

The ultraviolet absorbing layer constituting the transferable protective laminate 15 can be formed in the same manner as the ultraviolet absorbing layer constituting the transferable protective laminate 15 described in (2) above. Omit it.

Transferable protective laminate 15 of thermal transfer sheet 11
The adhesive layer constituting the layer has a function of facilitating the transfer of the transferable protective laminate 15 to the transfer target. As the adhesive forming this adhesive layer, use a heat-melting adhesive such as acrylic resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer, polyester resin, polyamide resin, polystyrene-acrylic copolymer, etc. You can The adhesive layer is formed by gravure coating, gravure reverse coating,
It can be performed by a known means such as roll coating, and the thickness of the adhesive layer is preferably about 0.5 to 5 μm. Further, the adhesive layer may contain additives such as an antioxidant and a fluorescent whitening agent.

In the thermal transfer sheet 11 of the present invention, an adhesive layer may be formed on the substrate sheet for the purpose of improving the adhesiveness between the substrate sheet and the transferable protective laminate 15.
The adhesive layer may be one that strengthens the adhesion between the base sheet and the protective layer, and for example, a polyurethane resin, an acrylic polyol resin, a vinyl chloride-vinyl acetate copolymer, etc. may be used alone or in combination. It can be formed by coating and drying. If necessary, a reactive curing agent such as polyisocyanate may be added, and a titanate or silane coupling agent may be used.

Further, the thermal transfer sheet 11 of the present invention described above.
, The dye layer is composed of three colors of yellow (Y), magenta (M), and cyan (C), but the thermal transfer sheet of the present invention is not limited to this, and a dye of any hue depending on the purpose. Layers can be provided.

[0073]

EXAMPLES Next, the present invention will be described in more detail by showing specific examples. (Example 1) A back layer ink having the following composition was applied to one surface of a polyethylene terephthalate film (Lumirror manufactured by Toray Industries, Inc.) having a thickness of 6 μm by a gravure coating method (coating amount 1.0 g / m ² (dry) )) And dried, and then held at 60 ° C. for 5 days for curing treatment to form a back surface layer.

(Composition of Ink for Back Layer) Polyvinyl butyral resin (Sekisui Chemical Co., Ltd. S-REC BX-1) ... 3.6 parts by weight Polyisocyanate (Dainippon Ink and Chemicals Co., Ltd. Vernock D750) ... 8.4 parts by weight-Phosphate ester-based surfactant (Prysurf A208S manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) ... 2.8 parts by weight-Talc (Microace P-3 manufactured by Nippon Talc Co., Ltd.) ... 6 parts by weight Methyl ethyl ketone / toluene (weight ratio 1/1) ... 190 parts by weight Next, on the surface opposite to the surface on which the back layer was formed of this polyethylene terephthalate film, a dye layer having the following composition was prepared by a gravure coating method. yellow each ink a, magenta, applied in order to face serial manner width 15cm cyan (length of the substrate sheet in the flow direction) (coating amount 1 g / m ² (dry ))
Then, it was dried to prepare a thermal transfer sheet of three-color thermal sublimation transfer system.

(Yellow Ink A) Disperse dye Quinophthalone dye represented by the following structural formula (III): 5.5 parts by weight Silicone graft polyvinyl acetal: 4.5 parts by weight: Represented by the following structural formula (IV) Polysiloxane compound: 0.1 parts by weight Toluene: 45 parts by weight Methyl ethyl ketone: 45 parts by weight

[0076]

Embedded image

[0077]

Embedded image (Magenta Ink A) Same as the above yellow ink except that magenta disperse dye (5.5 parts by weight of CI Disperse Red 60) was used as the disperse dye.

(Cyan ink A) The same as the above yellow ink except that a cyan disperse dye (CISolvent Blue 63) was used as the disperse dye. (Example 2) As in Example 1, a back layer was formed on one surface of the polyethylene terephthalate film.

Next, each ink B for the first layer of the dye layer having the following composition was prepared.

(Yellow Ink B) Disperse dye Quinophthalone dye represented by the above structural formula (III): 5.5 parts by weight Polyvinyl acetal: 4.5 parts by weight Toluene: 45 parts by weight Methyl ethyl ketone: 45 parts by weight Part (magenta ink B) Same as the above yellow ink except that magenta disperse dye (5.5 parts by weight of CI Disperse Red 60) was used as the disperse dye.

(Cyan Ink B) Same as the above yellow ink except that a cyan disperse dye (CISolvent Blue 63) was used as the disperse dye.

On the surface of the polyethylene terephthalate film opposite to the surface on which the back layer was formed, each of the inks for the dye layer described above was surface-sequentially arranged in the order of yellow, magenta, and cyan by a gravure coating method to have a width of 15 cm (base (Length in the flow direction of the material sheet) and dried to prepare a three-color thermal sublimation transfer type thermal transfer sheet. The application is
First, the first layer of each dye layer is formed using each of the yellow B, magenta B, and cyan B inks (coating amount 1 g /
m ² (when dried)), and then the second layer of each dye layer is formed using each of the same yellow A, magenta A, and cyan A inks as used in Example 1 (coating amount 1 g / m 2). ² (when dry)). (Example 3) A thermal transfer sheet of the thermal sublimation transfer system was produced in the same manner as in Example 1 except that each ink C for the dye layer having the following composition was used.

(Yellow Ink C) Disperse Dye Quinophthalone dye represented by the structural formula (III): 5.5 parts by weight Silicone graft polyvinyl acetal: 4.5 parts by weight: Represented by the structural formula (IV) Polysiloxane compound: 0.00045 parts by weight Toluene: 45 parts by weight Methyl ethyl ketone: 45 parts by weight (Magenta ink C) Magenta disperse dye (5.5 parts by weight of CI Disperse Red 60) is used as a disperse dye. Same as the above yellow ink.

(Cyan ink C) Same as the above yellow ink except that a cyan disperse dye (CISolvent Blue 63) is used as the disperse dye. (Example 4) A thermal transfer sheet of a thermal sublimation transfer system was produced in the same manner as in Example 1 except that each ink D for dye layer having the following composition was used.

(Yellow Ink D) Disperse dye (quinophthalone dye) 5.5 parts by weight Silicone graft polyvinyl acetal 4.5 parts by weight Polysiloxane compound represented by the structural formula (IV) 225 parts by weight Toluene ... 45 parts by weight Methyl ethyl ketone ... 45 parts by weight (Magenta ink D) Same as the above yellow ink except that magenta disperse dye (5.5 parts by weight of CI Disperse Red 60) is used as the disperse dye.

(Cyan ink D) Same as the above yellow ink except that a cyan disperse dye (CISolvent Blue 63) was used as the disperse dye. (Example 5) A thermal transfer sheet of thermal sublimation transfer system was prepared in the same manner as in Example 1 except that each ink E for dye layer having the following composition was used.

(Yellow Ink E) Disperse dye (quinophthalone dye) 5.5 parts by weight Silicone graft polyvinyl acetal 4.5 parts by weight Polysiloxane compound represented by the structural formula (IV) 1 part by weight-Toluene ... 45 parts by weight-Methyl ethyl ketone ... 45 parts by weight (Magenta Ink E) Same as the above yellow ink except that magenta disperse dye (5.5 parts by weight of CI Disperse Red 60) was used as the disperse dye.

(Cyan ink E) Same as the above yellow ink except that a cyan disperse dye (CISolvent Blue 63) is used as the disperse dye. (Example 6) A thermal transfer sheet of the thermal sublimation transfer system was produced in the same manner as in Example 1 except that each ink F for the dye layer having the following composition was used.

(Yellow Ink F) Disperse Dye Quinophthalone dye represented by the structural formula (III): 5.5 parts by weight Silicone graft polyvinyl acetal: 4.5 parts by weight Polysiloxane compound: 0.1 parts by weight Part: Toluene: 45 parts by weight Methyl ethyl ketone: 45 parts by weight (Magenta ink F) Same as the above yellow ink except that a magenta disperse dye (5.5 parts by weight of CI Disperse Red 60) was used as a disperse dye.

(Cyan ink F) Same as the above yellow ink except that a cyan disperse dye (CISolvent Blue 63) was used as the disperse dye. (Comparative Example 1) A thermal transfer sheet of the thermal sublimation transfer system was produced in the same manner as in Example 1 except that each ink G for the dye layer having the following composition was used.

(Yellow Ink G) Disperse dye (quinophthalone dye) 5.5 parts by weight Silicone graft polyvinyl acetal 4.5 parts by weight Polysiloxane compound represented by the structural formula (IV) 0001 parts by weight-Toluene ... 45 parts by weight-Methyl ethyl ketone ... 45 parts by weight (Magenta Ink G) Same as the above yellow ink except that magenta disperse dye (5.5 parts by weight of CI Disperse Red 60) was used as a disperse dye.

(Cyan ink G) Same as the above yellow ink except that a cyan disperse dye (CISolvent Blue 63) was used as the disperse dye. (Comparative Example 2) A thermal transfer sheet of a thermal sublimation transfer system was produced in the same manner as in Example 1 except that each ink H for dye layer having the following composition was used.

(Yellow ink H) Disperse dye (quinophthalone dye) 5.5 parts by weight Silicone graft polyvinyl acetal 2.25 parts by weight Polysiloxane compound represented by the structural formula (IV) 5 parts by weight Toluene ... 45 parts by weight Methyl ethyl ketone ... 45 parts by weight (Magenta Ink H) Same as the above yellow ink except that magenta disperse dye (5.5 parts by weight of CI Disperse Red 60) was used as the disperse dye.

(Cyan ink H) Same as the above yellow ink except that a cyan disperse dye (CISolvent Blue 63) was used as the disperse dye. (Comparative Example 3) A thermal transfer sheet of thermal sublimation transfer system was prepared in the same manner as in Example 1 except that each ink I for the dye layer having the following composition was used.

(Yellow ink I) Disperse dye (quinophthalone dye) 5.5 parts by weight Silicone graft polyvinyl acetal 4.5 parts by weight Toluene 45 parts Methyl ethyl ketone 45 parts by weight Magenta ink I Same as the above yellow ink except that magenta disperse dye (5.5 parts by weight of CI Disperse Red 60) was used as the disperse dye.

(Cyan Ink I) Same as the above yellow ink except that a cyan disperse dye (CISolvent Blue 63) was used as the disperse dye. (Comparative Example 4) A thermal transfer sheet of a thermal sublimation transfer system was produced in the same manner as in Example 1 except that each ink J for dye layer having the following composition was used.

(Yellow ink J) Disperse dye (quinophthalone dye) 5.5 parts by weight Silicone graft polyvinyl acetal 4.5 parts by weight Polysiloxane compound 0.1 parts by weight Toluene 45 parts by weight Methyl ethyl ketone: 45 parts by weight (magenta ink J) Same as the above yellow ink except that magenta disperse dye (5.5 parts by weight of CI Disperse Red 60) was used as the disperse dye.

(Cyan Ink J) Same as the above yellow ink except that a cyan disperse dye (CISolvent Blue 63) was used as the disperse dye. (Comparative Example 5) A thermal transfer sheet of a thermal sublimation transfer system was produced in the same manner as in Example 1 except that each ink K for the dye layer having the following composition was used.

(Yellow Ink K) Disperse Dye The quinophthalone dye represented by the above structural formula (III): 5.5 parts by weight Silicone graft acetal: 4.5 parts by weight Polysiloxane compound: 0.1 parts by weight -Toluene: 45 parts by weight-Methyl ethyl ketone: 45 parts by weight (magenta ink K) Same as the above yellow ink except that a magenta disperse dye (5.5 parts by weight of CI Disperse Red 60) was used as a disperse dye.

(Cyan ink K) Same as the above yellow ink except that a cyan disperse dye (CISolvent Blue 63) is used as the disperse dye. Evaluation of Thermal Transfer Sheet Each thermal transfer sheet prepared as described above (Examples 1 to 6,
With respect to Comparative Examples 1 to 5) and the following two types of transferred materials, the peeling property was evaluated under the following conditions, and the results are shown in Table 2 below.

(Transfer Material 1) A polyvinyl chloride card having the following material composition was used as the transfer material 1.

Polyvinyl chloride compound (polymerization degree 800, content of additives such as stabilizers: about 10% by weight): 100 parts by weight White pigment (titanium oxide): 10 parts by weight Plasticizer (dioctyl phthalate): 0 0.5 parts by weight (transferred material 2) As a substrate sheet, a synthetic paper having a thickness of 150 μm (Yupo FRG-150 manufactured by Oji Yuka Synthetic Paper Co., Ltd.) was used, and a receiving layer coating solution having the following composition was dried by a bar coater. The material to be transferred 2 was formed by coating the coating solution to a weight of 4 g / m ² and drying it to form a receptor layer.

Vinyl chloride-vinyl acetate copolymer (1000A manufactured by Denki Kagaku Co., Ltd.) 20 parts by weight Toluene / methyl ethyl ketone (weight ratio 1/1) 80 parts by weight (removability evaluation condition) The thermal energy of the thermal transfer sheet is applied to the thermal transfer sheet using the thermal head of the printer, which is connected to the electric signal obtained by color-separating the photograph of the face with the dye layer of the thermal transfer sheet, to form a full-color image. The peelability between the transfer body and the thermal transfer sheet was evaluated.
The thermal transfer sheet having no peeling property is heat-sealed to the transfer target to generate a printer jam.

[0104]

[Table 2] As shown in Table 2, the thermal transfer sheets (Examples 1 to 6) in which the dye layer contains the sublimable dye and the polysiloxane compound together with the silicon graft polymer have good releasability to any transfer target. It was equipped.

On the other hand, the thermal transfer sheet having insufficient polysiloxane compound content (Comparative Example 1) and the thermal transfer sheet containing no polysiloxane compound (Comparative Example 3) were not thermally fused to the material to be transferred 1. Occurred. Further, in the thermal transfer sheet (Comparative Example 2) in which the content of the polysiloxane compound was excessive, the adhesion between the dye layer and the base material sheet was poor, and abnormal transfer occurred.

[0106]

As described above in detail, according to the present invention, at least one dye layer of at least one color is provided on one surface of the substrate sheet by using at least a silicon graft polymer, a polysiloxane compound and a sublimable dye, and thermal transfer is performed. It is a sheet,
Since the polysiloxane compound contained in the dye layer has a high compatibility with the silicon graft polymer and an excellent releasing effect, the polysiloxane compound further enhances the releasability of the dye layer. It is possible to provide a thermal transfer sheet that stably exhibits excellent releasability without being affected by the material.

[Brief description of drawings]

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

FIG. 2 is a plan view showing another embodiment of the thermal transfer sheet of the present invention.

[Explanation of symbols]

 1, 11 ... Thermal transfer sheet 2 ... Substrate sheet 3, 13 (13Y, 13M, 13C) ... Dye layer 4 ... Back layer

Claims (7)

[Claims] 1. A thermal transfer characterized by comprising a dye layer of at least one color on one surface of a substrate sheet, the dye layer containing at least a sublimable dye, a silicon graft polymer and a polysiloxane compound. Sheet. 2. The thermal transfer sheet according to claim 1, wherein the dye layer further contains the same polymer as the polymer forming the silicon graft polymer. 3. The thermal transfer sheet according to claim 1, wherein the siloxane chain polymerization degree of the polysiloxane compound is in the range of 3 to 48. 4. The polysiloxane compound has at least one terminal or a functional group of --NH ₂ , --NHR (R is an alkyl group), an epoxy group, a hydroxyl group, an alkyl group and a phenyl group. The thermal transfer sheet according to any one of claims 1 to 3, characterized in that. 5. The dye layer contains the polysiloxane compound in an amount of 0.1 to 50 parts by weight with respect to 100 parts by weight of the polysiloxane chain component constituting the silicon graft polymer. Claims 1 to 4
The thermal transfer sheet according to any one of 1. 6. The thermal transfer sheet according to claim 1, wherein the dye layer has a two-layer structure. 7. The dye sheet-forming surface side of the substrate sheet is provided with at least one of a heat-fusible ink layer and a transferable protective laminate in the surface order with the dye layer. The thermal transfer sheet according to claim 6.