JPH0431085A - Image receiving paper for thermal transfer and its manufacturing method - Google Patents

Abstract

PURPOSE:To obtain the high density and quality of a transferred image and at the same time, an image-receiving sheet for thermal transfer without blocking by providing a thermally plastic intermediate layer and a cured redical- polymerizable compound layer at least on one side of a base. CONSTITUTION:A thermally plastic resin is applied to a base, then is dried and a radical-polymerizable compound is applied. Next, the applied compound is cured by irradiation with an ultraviolet or an electron beam to obtain a sublimable image-receiving sheet for thermal transfer. The thermally plastic resin used is such as, for example, an ester-compound resin, a urethane- compound resin, an amide-compound resin or a urea compound resin. The radical-polymerizable compound is composed mainly of an ultraviolet beam- polymerized resin or an electron beam polymerized resin, and if necessary, can be used with the addition of a reaction initiator. The recommended resins for use are compounds having a reaction group such as an acryloyl group, a methacryloyl group, a methacryloyl group or an epoxy group at the end or at the molecular side chain.

Description

Detailed Description of the Invention [A] Industrial Application Field The present invention is a dye-sublimation method that uses a sheet-like substrate such as paper, laminated paper, synthetic paper, or plastic film to provide excellent blocking properties and high transfer image density. This invention relates to image receiving paper for thermal transfer.

[B] Prior Art In recent years, sublimation type thermal transfer printers have been used as a means of color hard copying, particularly for reproducing multicolor gradation images. The principle of a sublimation type thermal transfer printer is to convert an image into an electrical signal, and then convert this electrical signal into a thermal signal using a thermal RAD to create a sheet coated with sublimation ink (ink donor sheet). ) is heated, the sublimated ink is fixed in an image-receiving layer that is in close contact with an ink donor sheet, and the image is reproduced. The surface of such image-receiving paper is generally provided with an image-receiving layer made of a polymer such as saturated copolymer polyester or polyacetate for fixing ink.

[C] Problems to be Solved by the Invention Although there is a demand for faster printing speed in dye-sublimation thermal transfer printers, this inevitably leads to an increase in thermal printing temperature. However, when performing high-temperature heat treatment on a thermal transfer image-receiving paper that uses paper or a plastic sheet as a base, it goes without saying that the base needs to be heat resistant, and the ink image-receiving layer made of a polymer provided on the image-receiving paper also needs to be heat-resistant. There was a problem in that the ink donor sheet melted, causing blocking between the ink donor sheet and the image receiving paper, and as a result, only hard copies with poor image reproducibility were obtained. It is true that a high transferred image density can be obtained by using thermoplastic resins, especially polyester resins that are said to have good dyeability with sublimation dyes, but this advantage is offset by blocking. Furthermore, if the smoothness of the surface of thermal transfer receiving paper is improved in order to improve the clarity of the image, blocking is even more likely to occur. A sublimation type heat-sensitive transfer image-receiving paper coated with an oligomer and cross-linked by radiation is known (Japanese Patent Laid-Open No. 173295/1983). but,
The following problems arise when such a sublimation type thermal transfer image-receiving paper is actually used. In other words, the sheet used for the substrate is a porous material, that is, plain paper, because it facilitates the diffusion of sublimation ink during printing, and also because it has appropriate cushioning properties and promotes adhesion with the ink donor sheet. It is said that base paper, glassine paper, coated paper, synthetic paper, or non-woven fabric is preferable, but when a radically polymerizable oligomer is applied to these porous materials, it instantly oozes out, making it difficult to obtain a smooth surface. . If a radically polymerizable oligomer is applied in an amount sufficient to compensate for this seepage, the curl after curing will be significant and new curl correction means will be required. Naturally, when a solvent is applied to improve the applicability of the radically polymerizable oligomer, the degree of seepage becomes more severe. It is obvious that image reproducibility and image sharpness deteriorate when the smoothness of the image receiving paper decreases in a sublimation type thermal transfer printer system.

More importantly, such resin seepage inevitably causes a decrease in opacity and whiteness of the porous material.

This deteriorates the characteristics of the printed image, especially in white areas. This poses a fatal problem when considering dye sublimation thermal transfer printing as a means of color hard copying.

Therefore, an object of the present invention is to use a thermoplastic resin that has excellent dyeability with respect to sublimation dyes, and at the same time provide a highly smooth radical polymer composition layer between the thermoplastic resin and the ink donor sheet, thereby achieving a high transfer rate. To obtain an image receiving paper for thermal transfer which has high image density and high image quality and is free from blocking at the same time.

Means for Solving the CD1 Problem The inventor of the present invention has conducted extensive research into means for solving the above-mentioned problems, and as a result has found the following method. Namely, (1) an image-receiving paper for thermal transfer characterized by having a thermoplastic intermediate layer and a hardened radically polymerizable composition layer on at least one side of a paper or film substrate;

(2) An image-receiving paper for thermal transfer, wherein the radically polymerizable composition comprises a compound having an acryloyl group, a methacryloyl group, or an epoxy group.

(3) After providing a thermoplastic intermediate layer on at least one side of the paper or film substrate and further providing a radically polymerizable composition layer thereon, the radically polymerizable composition layer is cured by ultraviolet irradiation or electron beam irradiation. A method for producing an image receiving paper for thermal transfer characterized by its stiffness.

(4) After providing a thermoplastic resin layer on at least one side of the paper or film substrate and further providing a radically polymerizable composition layer thereon, a substance having a smooth surface is brought into close contact with the radically polymerizable composition layer side, Curing the radically polymerizable composition layer by ultraviolet irradiation or electron beam irradiation from the opposite side of the substrate,
A method for producing an image-receiving paper for thermal transfer, which is characterized in that the paper is then peeled from a material having a smooth surface.

The present invention will be explained in detail below. That is, in the present invention, a thermoplastic resin is applied onto a substrate, dried, and then a radically polymerizable composition is applied and cured by ultraviolet irradiation or electron beam irradiation to obtain an image-receiving paper for sublimation type heat-sensitive transfer.

Examples of thermoplastic resins include those having ester bonds such as polyester resins, polyacrylic ester resins, polycarbonate resins, polyvinyl acetate resins, and styrene acrylate resins, and those having urethane bonds such as polyurethane resins and amide bonds. Polyamide resin (nylon) can be used as a material having a urea bond, urea resin can be used as a material having a urea bond, or a copolymer containing one or more of the constituent units of the above resins as a main component, such as vinyl chloride-acetic acid. It can also be used as a vinyl copolymer, styrene-butadiene copolymer, etc. Furthermore, the above resins can be used alone or in a mixture of two or more.

Any of the above thermoplastic resins can be suitably used for the purpose of the present invention, but polyester resins are particularly preferred for the purpose of increasing the dyeability of sublimation dyes and improving transfer density.

Further, the above resin can be dissolved in an organic solvent and applied onto the substrate, or can be emulsified in an aqueous solution and applied as an emulsion onto the substrate.

Furthermore, if necessary, additives such as dyes, pigments, wetting agents, antifoaming agents, dispersants, antistatic agents, mold release agents, and optical brighteners can also be contained.

In particular, regarding pigments, the purpose of improving blocking can be achieved by incorporating inorganic particles such as silica, calcium carbonate, kaolin clay, barium sulfate, titanium oxide, etc. into the thermoplastic resin layer or radically polymerizable composition layer. I can do it.

In addition, mold release agents can be used for the same purpose, but specifically, solid waxes such as polyethylene wax, amide wax, and Teflon powder, fluorine-based and phosphate-based surfactants, silicon compounds, etc. However, a curable silicone compound is preferably used because it is unlikely to cause bleeding of the transferred dye or a decrease in transfer or image density.

Examples of curing silicon compounds include reaction curing types, ionizing radiation curing types, catalyst curing types, etc., but the present invention is characterized in that it is irradiated with ultraviolet rays or electron beams after forming an image-receiving layer. , ionizing radiation-curable silicon compounds are advantageously used.

In addition, radically polymerizable compositions are mainly composed of ultraviolet polymerizable or electron beam polymerizable resins shown below, and these resins can be used without solvent or diluted with a solvent, if necessary. A reaction initiator is mixed and used.

The ultraviolet or electron beam polymerizable resin used in the present invention is a compound having a reactive group such as an acryloyl group, a methacryloyl group, or an epoxy group at the end of the molecule or in a side chain of the molecule, such as an unsaturated polyester or a modified unsaturated polyester. , acrylic polymer, acrylic monomer,
Methacrylic polymers, methacrylic onomers, monomers having vinyl unsaturated bonds, or oligomeric epoxy compounds can be used alone or in combination with other solvents. Typical examples are shown below.

(a) Polyester acrylate, polyester methacrylate Examples Eva, Aronix M-5300, Aronix M-
5400,70=X M-5500゜Aronix M
-5600. Aronix M-5700, Aronix M-6100. Aronix M-6200, Aronix M-63oo1 Aronix M-6500, Aronix M-71001 Aronix M-8030, Aroex M-8060, Aroex M-8100 (all trade names of Toagosei Kagaku Kogyo Co., Ltd.), Visco- door 00
, Viscoat 3700 (all trade names of Osaka Organic Chemical Industry Co., Ltd.), Kayarat HX-220, Kayarad HX
-620 (all trade names of Nippon Kayaku Co., Ltd.) (b) Epoxy acrylate, epoxy methacrylate, e.g. NK ester, EA-800, NK ester,
EPM-800 (product name of Shin-Nakamura Chemical Co., Ltd.), Viscotro 00, Viscoat 540 (product name of Osaka Organic Chemical Industry Co., Ltd.), Photomer 3016, Photomer 3082 (product name of San Nopco Co., Ltd.) (C) Urethane acrylate, urethane methacrylate, e.g. Aloex M-1100, Aloex M-
1200, Aloex M-1210゜Aloex M
-1250, Aroex M-1260, Aroex M-1300, Aroex M-1310 (all trade names of Toagosei Chemical Co., Ltd.), Viscoat 812, Viscoat 823, Viscoat) 823 (all of the above, Osaka Organic Chemical Industry Co., Ltd.) Kogyo Co., Ltd. product name), NK ester, U-108-A
, NK ester, U-48A (the above are trade names of Shin Nakamura Chemical Co., Ltd.) (d) Monofunctional acrylate, monofunctional methacrylate such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate,
2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, cyclohexyl acrylate,
Cyclohexyl methacrylate, benzyl acrylate, glycidyl methacrylate, N,N-dimethylaminoethyl acrylate, N5N-dimethylaminoethyl methacrylate, N5N-diethylaminoethyl methacrylate, butoxyethyl acrylate, and the like. Ethylene oxide-modified phenoxylated phosphoric acid acrylate, ethylene oxide-modified butoxylated phosphoric acid acrylate, and other product names of Toagosei Kagaku Kogyo Co., Ltd., such as Aroex M
-101, Aloex M-102, Aloex M1
11, Aloex M-11,3, Aloex M-1
14, Aloex M-11-7, Aloex M-1
52, Aloex M-154, and the like.

(e) Polyfunctional acrylate, polyfunctional methacrylate, such as 1,6-hexanediol diacrylate, 1
．． 6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, polyethylene glycol diacrylate,
Polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, pentaerythritol diacrylate, dipentaerythritol hexaacrylate,
Isocyanuric acid diacrylate, pentaerythritol triacrylate, isocyanuric acid triacrylate,
Examples include trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, ethylene oxide-modified pentaerythritol tetraacrylate, propylene oxide-modified pentaerythritol tetraacrylate, propylene oxide-modified dipentaerythritol polyacrylate, and ethylene oxide-modified dipentaerythritol polyacrylate. The product name of Toagosei Chemical Industry Co., Ltd. is Aloex M-21.
0, Aloex M-215, Aloex M-220
, Aloex M-230, Aloex M-233,
Aloex M-240, Aloex M-245, Aloex M-305, Aloex M-309, Aloex M-310, Aloex M-315, Aloex M-320, Aloex M~325, Aloex M-330, Aroex M-400, To-45
8, To-747, T0755, T) IIC, TA2, etc.

(f) Epoxy compounds such as glycidyl methacrylate, 1.3 bis(N,
N-jepoxypropylaminomethyl)cyclohexane, 1.3bis(N,N-jepoxypropylaminomethyl)benzene, and the like. The product names of Mitsubishi Gas Chemical Co., Ltd. are GE-'51.0 and TETRAD-X.
Examples include STETRAD-C.

Photoinitiators used in the present invention include acetophenones such as di- and trichloroacetophenone, benzophenone, Michler's ketone, benzyl, benzoin, benzoin alkyl ether, benzyl dimethyl ketal, tetramethylthiuram monosulfide, thioxanthone, azo compounds, etc. Yes, type of polymerization reaction of radically polymerizable resin and radically polymerizable silicone resin,
It is selected from the viewpoints of stability and compatibility with radical irradiation equipment. The amount of photoinitiator used is usually 1 to 5% based on the radically polymerizable resin or radically polymerizable silicone resin.
% range. Further, a storage stabilizer such as hydroquinone may be used in combination with the photoinitiator.

Substrates used in the present invention include glassine paper, high quality paper,
Art paper, coated paper and other paper bases, polyethylene,
Synthetic resin films such as polypropylene, polyethylene terephthalate, polyamide, etc., or laminated paper made by laminating these synthetic resins on one or both sides of paper,
Refers to synthetic paper, non-woven fabric, etc.

Examples of methods for applying the thermoplastic resin or radically polymerizable composition onto the substrate include blade coating, air doctor coating, squeeze coating, air knife coating, reverse roll coating, gravure roll and transfer roll coating, barcode coating, and curtain coating. A method such as coating is used.

The amount of the radically polymerizable composition applied onto the substrate varies depending on the type of substrate, but is 1 to Log/rrf, more preferably 2.
~5g/I.

Ionizing radiation for curing the radically polymerizable composition generally includes ultraviolet rays, α rays, β rays, γ rays, X rays, electron beams, etc., but α rays, β rays, γ rays and X rays are Since there is the issue of danger to the environment, ultraviolet rays and electron beams are effective because they are easy to handle and are widely used industrially.

When using an electron beam, the amount of electron beam irradiated is 0, 1
It is desirable to adjust within a range of about 10 Mrad. 0
．． ], below Mrad, sufficient irradiation effect cannot be obtained, and 1
0 M r a of 6 or more is not preferable because it deteriorates the paper or film substrate.

As the electron beam irradiation method, a scanning method, a curtain beam method, etc. are adopted, and an appropriate acceleration voltage for irradiating the electron beam is about 100 to 300 KV.

Further, when using ultraviolet rays, it is necessary to incorporate a sensitizer into the radical polymerization composition, but the above-mentioned sensitizers can be used as appropriate.

As the light source, for example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, a tungsten lamp, etc. are suitably used.

(E) Function The present invention provides an image-receiving paper for thermal transfer which has a thermoplastic resin intermediate layer and a hardened radically polymerizable composition layer on at least one side of a paper or film substrate in the production of an image-receiving paper for thermal transfer. Since the radically polymerizable composition layer exists between the donor sheet and the thermoplastic resin layer, blocking is prevented and penetration of the radically polymerizable composition is suppressed, resulting in good flatness and high transfer density.

CF) Examples The present invention will be explained in detail below using examples, but the content of the present invention is not limited to the examples.

Example 1 A dry solid content of 3.0 g of polyester resin emulsion (Pyronal MD-1330 Toyobo Co., Ltd.) was applied to one side of base paper (basis weight 110 g/11 ()) using an air knife coater.
/'rrf, and after drying, a radical polymerization composition with the following composition was applied at 5°0 g/rr? The mixture was coated to give an image-receiving paper for heat-sensitive transfer.

(Radical polymerizable composition) Acrylic monomer ~ M-22098 parts (Toagosei Chemical Industry Co., Ltd.) Benzyl dimethyl ketal IRGACURE951. 2 parts (Ciba Geigy) Example 2 Polyester resin emulsion (Pyronal MI)-1330: Toyobo) and silica were coated on one side of base paper (basis weight 110 g/rrf) with an air knife coater to a dry solid content of 3.0 g/IT each. ? After drying, the radical polymerization composition with the following composition was applied at 3.0 g/n using a gravure off-cerat coater.
RF, and irradiated with electron beam (acceleration voltage +17
It was cured at 5KV, irradiation dose IMrad) to obtain an image-receiving paper for thermal transfer.

(Radical polymerizable composition) Acrylic oligomer TC-12O3 (Nippon Kayaku) 50 parts Acrylic monomer M-21050 parts (Toagosei Chemical Industry) Example 3 Synthetic paper (YUBO FPG-11.0: Oji Yuka) Polyester resin emulsion (Pyronal MD-193) on one side
0.Toyobo) and silica each with a dry solid content of 2.5 g.
/rrf and 0.3 g/ffl using an air knife coater, and after drying, a radical polymerization composition with the following formulation was applied using a gravure offset coater to give a coating weight of 2.5 g/m. It was cured by electron beam irradiation (acceleration voltage=150 KV, irradiation dose 1.5 Mrad) to obtain an image-receiving paper for thermal transfer.

(Radical polymerizable composition) Acrylic oligomer M-21095 parts (Toagosei Kagaku Kogyo) Thyroid 162 5 parts (Fuji Davison) Example 4 Polyester resin emulsion ( Pyronal MD-1330: Toyobo) and silica were applied with an air knife coater so that the dry solid content was 3.0 g/n (and 0.5 g/rrf), and after drying, a radical polymerization composition with the following composition was applied. was coated using a gravure offset coater at a concentration of 3.0 g/d, a polyester film was pasted on the coated surface, and after curing by electron beam irradiation (acceleration voltage 200 KV, irradiation dose 1.5 Mrad), the polyester film was peeled off. An image receiving paper for thermal transfer was obtained.

(Radical polymerizable composition) Acrylic oligomer TC-12O3 (Nippon Kayaku) 50 parts Acrylic monomer M-21,045 parts (Toagosei Kagaku Kogyo) Thyroid 161 5 parts (Fuji Davison) Comparative example 1 Base paper (tsubo ffl i ] , Og/rrf) with an air knife coater on one side of the polyester resin emulsion (
Pyronal MD-1,330 Toyobo) and silica were coated at a dry solid content of 3.0 g/r+ (0.5 g/rd) and dried to obtain an image receiving paper for thermal transfer.

Comparative Example 2 Polyester resin emulsion (Pyrocur MD-19
30 Toyobo) and silica each with a dry solid content of 2.5 g/
rI? The film was coated using an air knife coater to give a coating weight of 0.3 g/rrr, and dried to obtain an image receiving paper for thermal transfer.

Comparative Example 3 A radical polymerization composition with the following composition was applied to one side of base paper (basis weight: 1-0 g/i) using a gravure offset coater to give a concentration of 3.0 g/ld, and then irradiated with an electron beam ( Accelerating voltage: 175 KV, irradiation dose: Mrad) to obtain an image receiving paper for thermal transfer.

(Radical polymerizable composition) Acrylic oligomer ~ TC-12O3 (11 wood chemical) 50 parts Acrylic monomer M-21050 parts (Toagosei Chemical Industry Co., Ltd.) The thus obtained image receiving paper for thermal transfer was coated with a Hitachi color video printer VY-50. Thermal transfer recording was performed using an ink film for a Hitachi color video printer, and the resulting transfer density and blocking (the state of fusion between the image-receiving sheet and the ink film) were evaluated.

Regarding the transfer density, the value of the cyan image density measured using a Macbeth densitometer is shown. Regarding blocking, a state in which no fusion was observed was evaluated as ◯, and a state in which fusion was observed was evaluated as ×, and the results are shown in Table 1.

(Table 1) [G] Effect A receiver paper for thermal transfer having a thermoplastic resin intermediate layer and a hardened radically polymerizable composition layer on at least one side of a paper or film substrate as in the present invention is prepared, and the thermoplastic resin layer is By performing thermal recording in a system in which the ink does not come into direct contact with the ink donor sheet, we were able to obtain a high image density and an image-receiving paper for thermal transfer without blocking.

Claims (4)

[Claims] (1) An image-receiving paper for thermal transfer characterized by having a thermoplastic resin intermediate layer and a hardened radically polymerizable composition layer on at least one side of a paper or film substrate. (2) The image-receiving paper for thermal transfer according to claim 1, wherein the radically polymerizable composition comprises a compound having an acryloyl group, a methacryloyl group, or an epoxy group. (3) After providing a thermoplastic resin intermediate layer on at least one side of the paper or film substrate and further providing a radically polymerizable composition layer thereon, the radically polymerizable composition is cured by ultraviolet irradiation or electron beam irradiation. A method for producing an image-receiving paper for thermal transfer, characterized by the following. (4) After providing a thermoplastic resin intermediate layer on at least one side of the paper or film substrate and further providing a radically polymerizable composition layer thereon, a substance having a smooth surface is adhered to the radically polymerizable composition layer side. A method for producing an image-receiving paper for thermal transfer, comprising curing the radically polymerizable composition layer by irradiating ultraviolet rays or electron beams from the opposite side of the substrate, and then peeling it off from a substance having a smooth surface.