JPH04113891A - Manufacture of image receiving sheet for thermal transfer - Google Patents

Abstract

PURPOSE:To provide a highly smooth precoat layer stably by using a radical polymerizable compound with post-curing Tg of higher than a specified temperature as a precoat layer, then allowing the precoat layer to come in contact with an area between a support and a highly smooth surface while the layer remains plastic and peeling the layer off the highly smooth surface after being cured using emitted ultraviolet beam or electron beam. CONSTITUTION:A radical polymerizable compound with post-curing Tg of higher than 70 deg.C is used as a precoat layer, then the precoat layer is allowed to come in contact with an area between a support and a highly smooth surface while the layer remains plastic and is cured using an emitted ultraviolet beam or electron beam. Next, a highly smooth precoat layer is formed on the support by peeling the precoat layer off the highly smooth surface. The recommended thermally plastic resin is especially polyester resin from a viewpoint of coat applicability of sublimable dye. The recommended ultraviolet or electron beam- polymerizable resin is such as a compound having a reaction group such as an acryloyl group, a methacryloyl group or an epoxy group at a molecular terminal or a molecular side chain. A monomer or an oligomer having a vinyl-type unsaturated bond, unsaturated polyester and an epoxy compound can be used independently or with any other solvent. The recommended content of a radical polymerizable compound is 2 to 10g/m<2>, although variable depending on the type of a base.

Description

DETAILED DESCRIPTION OF THE INVENTION [A] Industrial Field of Application The present invention involves coating an image-receiving layer on a pre-coat layer mainly composed of a highly smooth radically polymerizable composition provided on a support. This paper relates to a dye-sublimation type heat-sensitive transfer image receiving paper that has high image density and excellent anti-blocking properties, as well as high image quality without image unevenness or image blurring, and in particular relates to a manufacturing method for stably forming highly smooth pre- and coating layers. It is something.

CB) 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 head to print a sheet coated with sublimation ink (ink donor sheet). The heated and sublimated ink is fixed on an image-receiving paper 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 In recent years, printers using a sublimation type thermal transfer system are required to increase printing speed and improve transferred image quality.

When a porous support such as plain paper base paper is used as a support for image receiving paper for thermal transfer, the smoothness is low and the image quality is poor. There is no choice but to use paper, synthetic resin films such as polyethylene, polypropylene, polyethylene terephthalate, polyamide, etc., or laminated paper or synthetic paper in which these synthetic resins are laminated on one or both sides of paper, and these are heat-resistant. This, combined with its high smoothness, causes shrinkage of the support surface due to heat and blocking with the ink donor sheet, leading to a decrease in image quality. Furthermore, since increasing the printing speed inevitably leads to an increase in the thermal printing temperature, there is a tendency to further worsen the above-mentioned situation. One way to solve these problems is to use a mixture of a thermoplastic resin and a radically polymerizable oligomer in the image-receiving layer, and then cure the mixture to improve the heat resistance.
JP-A No. 63-74693, etc.) and a method of providing an ultraviolet curing resin layer on the image-receiving layer (JP-A No. 2-151484, etc.) have also been proposed; If the method is advanced, there is a drawback that the recording density becomes insufficient.

On the other hand, there is a method in which a radically polymerizable oligomer having a Tg of the cured product or less than 65°C is applied to the base material and crosslinked by radiation (JP-A-6
2-173295), but if this method is used to obtain high-density recordings, the recorded images tend to smear and have poor storage stability. In addition, in order to obtain a transferred image with high image quality without image unevenness, it is preferable that the surface smoothness of the image receiving layer is high, and the surface smoothness is required for at least 2000 seconds or more, preferably 5000 seconds or more. For this purpose, it is desirable that the precoat layer is also highly smooth, and smoothness of 5000 seconds or more is required. A radically polymerizable composition is applied as a precoat layer onto a substrate, and after contacting the highly smooth surface with the support while the precoat layer has plasticity, the highly smooth surface is cured by ultraviolet irradiation or electron beam irradiation. A highly smooth precoat layer can be provided on the support by peeling from the surface. In particular, when the highly smooth surface is a metal mirror surface such as a metal roll or a plastic film, the highly smooth surface can be provided on the support. but,
In the case of a relatively soft film with a Tg of less than 70°C after curing of the radical polymerization composition, a portion of the precoat layer may be transferred to the metal surface or plastic film, making it difficult to create a uniform surface on the support, resulting in color fading and discoloration. This results in image unevenness such as unevenness, which causes deterioration in image quality. Further, although such a relatively soft film can obtain a high transferred image density, it has the disadvantage that it is prone to image blurring and lacks storage stability. Therefore, an object of the present invention is to obtain an image-receiving paper for thermal transfer that has high transferred image density and good anti-blocking properties, and is free from image bleeding and image unevenness.

Means for Solving the CD3 Problems 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.

That is, in a thermal transfer image-receiving paper in which a pre-coat layer containing a radically polymerizable composition as a main component and an image-receiving layer containing a thermoplastic resin as a main component are laminated on a support, the pre-coat layer is coated with a resin after curing. A radically polymerizable composition having a Tg of 70°C or higher is used, and after contacting the highly smooth surface with the support while the precoat layer has plasticity, the high smoothness is cured by ultraviolet irradiation or electron beam irradiation. This is a method for producing an image-receiving paper for thermal transfer, characterized in that a highly smooth precoat layer is provided on a support by peeling from a smooth surface.

This is a method for producing an image-receiving paper for thermal transfer, characterized in that the highly smooth surface is a metal mirror surface such as a metal roll or a plastic film.

This is a method for producing an image-receiving paper for thermal transfer, characterized in that the radically polymerizable composition is made of a compound having an acryloyl group, a methacryloyl group, or an epoxy group.

This is a method for producing an image-receiving paper for thermal transfer, characterized in that the thermoplastic resin is a linear saturated polyester resin.

The present invention will be explained in detail below.

That is, in the present invention, while the precoat layer coated on the support has plasticity, the support is brought into contact with a highly smooth surface such as a metal roll or a plastic film, and then cured by ultraviolet ray irradiation or electron beam irradiation. After a highly smooth precoat layer is provided on the support by peeling from the surface, a thermoplastic resin layer is applied onto the layer to obtain an image receiving paper for sublimation type thermal 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 measuring the improvement of 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.
The present invention is characterized in that it is irradiated with ultraviolet rays or electron beams after forming the image-receiving layer, and an ionizing radiation-curable silicon compound is conveniently 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: Aronix M-5300, Aronix M-
5400, Aronix M-5500, Aronix M
-5600, Aronix M-5700, Aronix M-6100, Aronix M-6200, Aronix M-6300, Aronix M-6500, Aronix M-7100, Aronix M-8030, Aronix M-8060, Aronix M-8100 (and above) , Toagosei Chemical Industry Co., Ltd. product name), Viscodoor 00
, Visco) 3700 (all trade names of Osaka Organic Chemical Industry Co., Ltd.), Kayarad 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 (trade name of Shin-Nakamura Chemical Co., Ltd.), Viscotro 00, Viscoat 540 (trade name of Osaka Organic Chemical Industry Co., Ltd.), 7 Otomer 3016, Photomer 3082 (trade name of San Nopco Co., Ltd.) Product Name) (C) Urethane acrylate, urethane methacrylate, e.g. Aloex M-1100, Aloex M-
1200, Aloex M-1210, Aloex M
-1250, Aloex M-1260, Aloex M-1300, Aloex M-1310 (trade names of Toagosei Kagaku Kogyo Co., Ltd.), Viscoat 812, Viscoat 823, Viscoat 823 (all trade names of Osaka Organic Chemical Industry Co., Ltd.) 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, N,N-dimethylaminoethyl methacrylate, N,N-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 Chemical Industry Co., Ltd., such as Aroex M-
101, Aloex M-102, Aloex M-1
11, Aloex M-113, Aloex M-11
4. Aloex M-117, Aloex M-152
, 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 M215, 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, Aloex M-400, TO-458
, To-747, T0755, THIC, TA2, etc.

(f) Epoxy compounds such as glycidyl methacrylate, 1,3 bis(N,
Examples include N-jepoxypropylaminomethyl)cyclohexane and I,3bis(N,li-jepoxypropylaminomethyl)benzene. The product names of Mitsubishi Gas Chemical Co., Ltd. are GE-510 and TETRAD-X.
, TETRAD-C, etc.

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,
Selected from the viewpoints of stability and compatibility with radical irradiation equipment. The amount of photoinitiator used is usually 1 to 1 to 1 to 100% of the radically polymerizable resin or radically polymerizable silicone resin.
It is in the range of 5%. Further, a storage stabilizer such as hydroquinone may be used in combination with the photoinitiator.

Supports used in the present invention include plain paper base paper, coated papers such as art paper and coated paper, and synthetic resin films such as polyethylene, polypropylene, polyethylene terephthalate, and polyamide, or films coated with these synthetic resins on one side, or Laminated paper laminated on both sides, synthetic paper, etc. are used.

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 20 g/nf, more preferably 2 to 20 g/nf.
It is 10g/ba.

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 M r a d. If it is less than 0.1 Mrad, a sufficient irradiation effect cannot be obtained, and if it is more than 10 Mrad, it deteriorates the paper or film substrate, which is not preferable.

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

Further, when using ultraviolet rays, it is necessary to incorporate a sensitizer into the radical polymerization composition, and the sensitizers listed above 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 in which a highly smooth hardened layer of a radically polymerizable composition is provided as a precoat layer on a support in the production of an image-receiving paper for thermal transfer, and a thermoplastic resin layer is provided thereon. The present invention relates to a method for producing an image-receiving paper for sublimation type thermal transfer, which is paper and has high image density, excellent blocking resistance, and high image quality without image unevenness or image blurring.

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 radical polymerization composition with the following composition was coated on art paper at 8.0 g/n using a gravure offset coater.
After applying the coating so that
, an irradiation dose of 1.5 Mrad), the polyester film was peeled off, and then the polyester resin emulsion (Pyronal MD-13
30=Toyobo) and silica each have a dry solid content of 3,0g
/rd and 0. It was applied at a concentration of 5 g/lrr and dried to obtain an image-receiving paper for thermal transfer.

(Radical polymerizable composition) Acrylic monomer M-21095 parts (Toagosei Chemical Industry Co., Ltd.: Tg 75°C) Thyroid 161
5 parts (Fuji Davison) Example 2 After applying the following composition as a radical polymerization composition onto RC paper using a gravure offset coater at a rate of 4.5 g/i, a polyester film was pasted on the applied surface, After curing by electron beam irradiation (acceleration voltage: 150 KV, irradiation dose 2.Q Mrad), the polyester film was peeled off, and then a polyester resin emulsion (Pyronal MD-1330) was coated with an air knife coater.
: Toyobo) and silica each with a dry solid content of 3.0 g/d.
and 0.5 g/rr, and dried to obtain an image-receiving paper for thermal transfer.

(Radical polymerizable composition) Acrylic monomer M-30990 parts (Toagosei Chemical Industry, Tg >250°C) Thyroid 161
10 parts (Fuji Davison) Example 3 12.5 g of the following composition as a radical polymerization composition was applied onto plain paper base paper using a gravure offset coater.
/rrf, and after contacting the coated surface with a metal roll, electron beam irradiation (acceleration voltage: 2
After curing the precoat layer at 50KV, irradiation dose: 2°5 Mrad), it was peeled off from the metal roll and the precoat layer was placed on plain paper base paper, and then a polyester resin emulsion (Pyronal MD-13
30: Toyobo) and silica each with a dry solid content of 3.0g
/rr! It was coated at a concentration of 0.5 g/lrf and dried to obtain an image-receiving paper for thermal transfer.

(Radical polymerizable composition) Acrylic monomer M-31085 parts (Toagosei Chemical Industry Co., Ltd.: Tg 120°C) Thyroid 161
15 parts (Fuji Davison) Example 4 11.5 g of the following composition as a radical polymerization composition was applied onto plain paper base paper using a gravure offset coater.
/nf, and after contacting the coated surface with a metal roll, electron beam irradiation (acceleration voltage: 25
After curing the precoat layer with 0KV and irradiation dose of 2°5 Mrad), it was peeled off from the metal roll and the precoat layer was provided on the plain paper base paper, and then a polyester resin emulsion (Pyronal MD-133
0 = Toyobo) and silica each with a dry solid content of 3.0 g/
ffl and 0.5 g/rd, and dried to obtain an image receiving paper for thermal transfer.

(Radical polymerizable composition) Acrylic monomer M-32585 parts (Toagosei Chemical Industry Co., Ltd.: Tg 187°C) Thyroid 161
15 parts (Fuji Davison) Comparative Example 1 A radical polymerization composition with the following composition was coated on art paper at 8.0 g/n using a gravure offset coater.
(After coating, a polyester film is pasted on the coated surface and irradiated with an electron beam (acceleration voltage: 200KV).
, irradiation dose 2. After curing with QMrad), the polyester film was peeled off, and then the polyester resin emulsion (Pyronal MD-13) was coated with an air knife coater.
30: Toyobo) and silica each with a dry solid content of 3°0g
/ Boto 0.5g/rr! The mixture was coated and dried to obtain an image-receiving paper for thermal transfer.

(Radical polymerizable composition) Acrylic monomer M-560095 parts (Toagosei Chemical Industry Co., Ltd.: Tg 45°C) Thyroid 161
5 parts (Fuji Davison) Comparative Example 2 A radical polymerization composition having the following composition was coated on a plain paper base paper using a gravure offset coater. , 0.
After coating at a concentration of 5 g/rrr, the coated surface was brought into contact with a metal roll, and the precoat layer was cured by electron beam irradiation (acceleration voltage: 250 KV, irradiation dose: 2°5 Mrad) from the plain paper base paper surface. After peeling from the roll and providing a precoat layer on the plain paper base paper, a polyester resin emulsion (Pyronal M
D-1330 Toyobo) and silica in a dry solid content of 3
．． The coating was coated at a concentration of 0 g/i and 0.5 g/H and dried to obtain an image receiving paper for thermal transfer.

(Radical polymerizable composition) Acrylic monomer M-121085 parts (Toagosei Chemical Industry Co., Ltd. Tg 15°C) Thyroid 161
15 parts (Fuji Davison) Comparative Example 3 10.0 g of the following formulation as a radical polymerization composition was applied onto plain paper base paper using a gravure offset coater.
/rtf, and after contacting the coated surface with a metal roll, electron beam irradiation (acceleration voltage: 2
After curing the precoat layer at 50KV, irradiation dose: 2°5 Mrad), it was peeled off from the metal roll and the precoat layer was placed on plain paper base paper, and then a polyester resin emulsion (Pyronal MD-13
30, Toyobo) and silica each with a dry solid content of 3.0 g.
/n(and 0.5 g/rrf) and dried to obtain an image receiving paper for thermal transfer.

(Radical polymerizable composition) Acrylic monomer M-650085 parts (Toagosei Chemical Industry Co., Ltd.: Tg 40°C) Thyroid 161
15 parts (Fuji Davison) The ink donor sheet was stacked facing each other on the obtained thermal transfer image receiving paper, and the ink donor sheet was heated from the donor sheet surface at 150°C for 5 seconds to evaluate.The transferred image density and blocking were good. In terms of image unevenness and image blurring, large differences were observed between the Examples and Comparative Examples.

Regarding image blurring and image unevenness, the state where no image was observed was evaluated as ○, and the state where it was completely observed was evaluated as x, and the results are shown in Table 1.

(Table 1) In a manufacturing method for manufacturing a thermal transfer image-receiving paper, which is characterized in that a thermoplastic resin layer is provided as an image-receiving layer after the formation,
By using a radically polymerizable composition having a Tg of 70° C. or higher after curing in the precoat layer, a receiving paper for thermal transfer that has high image density, excellent blocking resistance, and high image quality without image bleeding or unevenness can be obtained. I was able to do it.

CG] Effect

Claims (4)

[Claims] (1) In a thermal transfer image-receiving paper formed by laminating a pre-coat layer containing a radically polymerizable composition as a main component and an image-receiving layer containing a thermoplastic resin as a main component on a support, the pre-coat layer has a Tg after curing. using a radically polymerizable composition having a temperature of 70° C. or higher, and after contacting the highly smooth surface with the support while the precoat layer has plasticity, the highly smooth surface is cured by ultraviolet irradiation or electron beam irradiation. A method for producing an image-receiving paper for thermal transfer, which comprises providing a highly smooth precoat layer on a support by peeling the paper. (2) The method for producing an image-receiving paper for thermal transfer according to claim 1, wherein the highly smooth surface is a metal mirror surface such as a metal roll or a plastic film. (3) The method for producing an image-receiving paper for thermal transfer according to claim 1 or 2, wherein the radically polymerizable composition comprises a compound having an acryloyl group, a methacryloyl group, or an epoxy group. (4) The method for producing an image-receiving paper for thermal transfer according to claim 1, 2 or 3, wherein the thermoplastic resin is a linear saturated polyester resin.