JPH0784106B2 - Sublimation type thermal transfer recording image receiving sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention is a sublimation type in which recording is performed by sublimation transfer of a coloring material from a thin support to a recording medium facing the thin support by heating with a thermal head or the like. A sublimation type thermal transfer recording image receiving sheet suitable for use in a thermal transfer recording system is provided with solvent resistance, weather resistance, abrasion resistance and heat resistance, and is improved in discoloration property, resublimation property, etc. to improve the record holding property. And a sublimation type thermal transfer recording image receiving sheet.

(B) Conventional Technology Conventionally, this type of recording method is disclosed in, for example, Japanese Patent Laid-Open No. 57-169370,
Known as Japanese Patent Laid-Open No. 58-197089, it is a recording method characterized by small size, low cost, and easy maintenance and inspection operation as a means for making a hard copy of a TV image or an image on a computer terminal. It is called the sublimation type thermal recording method and is receiving attention.

In this method, a color material sheet in which a sublimable color material is applied to a thin sheet support such as paper is opposed to a thermal transfer recording image receiving sheet, and the image is recorded on the recording image receiving sheet by heat transfer and dyeing with a thermal head or the like. It is a thing.

Since the colors of the color materials are yellow, magenta, cyan and, if necessary, black, and heat transfer is performed sequentially, a full-color high-gradation hard copy can be obtained.
As a conventional technique, for example, as shown in JP-A-57-107885, it is known to provide a coating layer containing saturated polyester as a recording image-receiving sheet,
As shown in JP-A-60-101090, it is common practice to use synthetic paper as a support in order to exert the characteristics of high gradation. Further, for general consumers who prefer a paper-like recording image-receiving sheet, a layer made of a sulfonated phthalic acid isomer-containing polyester resin may be provided on the paper surface as shown in JP-A-61-3796. As shown in Japanese Patent Application No. 60-178363, a sublimation type thermal transfer image receiving paper containing a saturated polyester and higher fatty acid amides on the surface of the paper has been developed.

(C) Problems to be Solved by the Invention An image-receiving sheet printed in a sublimation type thermal transfer recording system has a function of preventing fading of a transferred image, improving light resistance, weather resistance, and divergence due to resublimation of a sublimable coloring material. The cover film is subjected to thermocompression bonding in order to obtain effects such as prevention, gloss, solvent resistance, abrasion resistance, and improvement of color development by re-diffusion of sublimable coloring material. Usually, the thermocompression bonding of the cover film is performed by heating and pressurizing with a laminator provided separately from the thermal transfer printer.

However, in mounting such a cover film, since a thick film that is convenient for handling is used, the problem of curling after thermocompression bonding becomes a problem, so that the cover film is prevented from contaminating the heating / pressurizing roll when melted. It is difficult to position because it is made small,
As shown in Japanese Utility Model Publication No. 60-69672, even if a resin layer capable of being melt-transferred in a certain size is previously provided on the heat-resistant base material, the heat-resistant base material does not peel from the heat-resistant base material after melt transfer. There was a problem such as the necessity or treatment of the used heat resistant substrate.

In the sublimation type thermal transfer recording system of the present invention, the treatments for preventing discoloration and re-sublimation are performed, and the coloring property, gloss, weather resistance,
It is intended to provide a sublimation type thermal transfer recording image-receiving sheet which has good light resistance, solvent resistance, heat resistance and abrasion resistance and is easy to handle.

(D) Means for Solving the Problem That is, according to the present invention, in an image receiving sheet used for sublimation type thermal transfer recording, the image receiving sheet is provided on a support (1) as shown in FIG. 1 and on the support. A fixing layer (2) made of a resin that easily fixes the heat sublimable coloring material, and a gaseous heat sublimable coloring material provided on the fixing layer easily permeate and heat / pressurize. The problem is solved by using a transparent layer (3) made of a resin capable of forming a film. Transmission layer (3) in the present invention
The role of is shown in FIG. 2 by transmitting all or part of the gaseous sublimable coloring material to the fixing layer (2) at the time of thermal transfer recording, and performing heating or pressure treatment after thermal transfer recording. As shown in the drawing, the coating layer (4) protects the inner fixing layer (2) and the recorded image (5) from external factors such as solvent and light, and the heat sublimable color that constitutes the recorded image (5). It prevents discoloration due to resublimation of the material.

The support (1) of the image-receiving sheet used in the present invention is required to have good surface smoothness and appropriate cushioning properties in view of the adhesion to the thermal head, and plain paper, surface-coated paper, synthetic paper, It is possible to use a synthetic resin film, a film in which this is filled with a white pigment, or a film which is whitened by fine foaming.

Fixing layer (2) provided on the support (1) of the image receiving sheet
Is a layer that substantially fixes the heat sublimable coloring material, polyethylene terephthalate, polypropylene terephthalate, poly 1,4-cyclohexane dimethylene ethylene terephthalate, polyacrylate, polymethacrylate sulfonated phthalic acid and ethylene glycol Polyesters such as polyesters are typical, but polymers copolymerized randomly for the purpose of improving crystallinity, melting point and solubility, polymers containing higher fatty acid amides for the purpose of improving adhesiveness and color development. Alternatively, a polymer having a carboxylic acid residue left can be used.

As the fine-grained thermoplastic organic polymer used in the permeable layer (3), polyethylene having a low fixing property of the heat sublimable coloring material,
Polyolefins such as polypropylene are preferred. The finely divided thermoplastic organic polymer used in the present invention is preferably a so-called slurry-like plastic pigment, which is produced by emulsion polymerization of one or more vinyl monomers, and its dried and solid plastics. Can be obtained as a fine powder pulverized by various means, a powder formed into fine particles, or the like. The size of these thermoplastic organic polymer fine particles is usually 0.01 μm to 50 μm in diameter, preferably 0.05 μm to 30 μm, to form the voids necessary for permeation of the vaporized sublimable coloring material. be able to.

As the adhesive used for fixing the thermoplastic organic polymer fine particles, for example, polyvinyl alcohol and its derivatives are synthetic resin adhesives such as styrene-butadiene copolymer, and the fixing layer (2). It can be selected in consideration of good adhesiveness with and good permeability of the gas state sublimable coloring material.

If necessary, a thickener, a flow modifier, a foaming agent, a foam suppressor,
It does not matter at all to use an ultraviolet-ray inhibitor, an antioxidant, a light stabilizer, or a plasticizer together with the thermoplastic organic polymer fine particles or to use them in a mixed state.

The sublimation type thermal transfer image-receiving sheet of the present invention can be obtained by sequentially coating and drying the fixing layer (2) and the transmission layer (3) on the support (1). The coating machine is generally a pigment coated paper. Any blade coater, air knife coater, roll coater, blush coater, curtain coater, chanbrex coater, bar coater, gravure coater, etc. that are used in manufacturing can be applied.

Drying after coating is carried out by an ordinary drying method such as a gas heater, an electric heater, a steam heating heater, or various methods such as hot air heating to form a coating layer. At that time, the temperature applied to the coating layer needs to be lower than the melting point of the thermoplastic organic polymer particles used. When the coating layer is dried to reach a temperature higher than the melting point of the thermoplastic organic polymer, the thermoplastic organic polymer fine particles are fused and formed into a film, which is an important function of the permeable layer (3). This impedes the permeation of the heat-sublimable colorant and reduces the color developability and fixability.

The role of the permeable layer (3) is to pass through the flying gas-state sublimable coloring material and immediately transfer a part or all of it to the fixing layer (2) having a high fixing ability. To form a film and protect the recorded image from solvent, light and air.

Of course, if the permeable layer (3) is too thick, the gaseous thermally sublimable coloring material cannot pass through the permeable layer (3), so the permeable layer (3) is preferably as thin as possible within the range capable of forming a film.

The present invention requires a step of converting the thermoplastic organic polymer of the transparent layer (3) of the image-receiving sheet having a thermal transfer recording image into a transparent coating layer (4) by heating and melting.
As a method of forming the permeable layer (3) into a film, in addition to a method of simply applying heat to form a melt film, a method of transferring the shape of the roll surface to a film surface by passing it through a cooling roll immediately after heating, or peeling A method of transferring the surface shape of the heat-resistant film to the surface of the coating by heat-treating the heat-resistant film is also possible. The heating method is not particularly limited. Such a film-forming treatment of the permeable layer (3) may be carried out immediately after the thermal transfer recording by the heating portion provided in the thermal transfer printer, or after recording the whole screen, a heating and pressurizing device different from the printer is used. You may make it into a film.

It is advantageous for forming a film that a substance that lowers the melting point of the thermoplastic organic polymer when heat is applied, particularly a plasticizer, is applied in advance and then heated.

Further, the elastic modulus of the thermoplastic polymer, a substance that lowers the glass transition point or a substance that decreases the melt viscosity is added in advance, or it is applied from the outside and then heat treated,
It is desirable for facilitating film formation. Such substances mainly include organic acid esters, phosphoric acid esters, sulfonic acid esters and amides, aliphatic esters, polyesters, epoxy plasticizers, chlorine-containing plasticizers and the like. Phthalates are particularly effective.

The sublimable colorant used in the present invention has a sublimation point of 70.
The temperature is preferably in the range of to 400 ° C, more preferably 150 to 250 ° C. For example, Disperse Blue 20
(Product name Duranol Blue 2G), Dispense Yellow 42
(Product name Resulin Yellow GR), Disperse Red 1
(Trade name Geliton Scarlet B), etc., other quinalizarin dyes, dispersible monoazo dyes, dispersible anthraquinone dyes, disperse nitrodiphenylamine dyes, anthracene dyes, etc., and as a support for sublimable coloring materials, From the viewpoint of thermal conductivity of the thermal head, thin sheets with good thermal conductivity are desirable, paper such as condenser paper, glassine paper, synthetic paper, synthetic resin film can be used,
A synthetic resin film is preferable from the viewpoint of image quality uniformity.

In addition, inorganic fine particles such as silica, calcium carbonate, kaolin, clay and colloidal silica may be added from the viewpoint of preventing thermal fusion between the color material sheet and the image receiving sheet.

The color material sheet can be prepared by using an adhesive that does not prevent sublimation and making it a dye sheet by gravure printing or the like.

(E) Action The fixing layer (2) formed on the support (1) thus formed
And a transparent layer (3) made of thermoplastic organic polymer particles are provided on the transparent layer. After thermal transfer recording on a sublimation type thermal transfer recording image-receiving sheet, the transparent layer (3) is heat-treated to form a film. Solvent resistance, light resistance, weather resistance, abrasion resistance and heat resistance are improved by the action of the layer (4), and at the same time, the sublimation dye is prevented from fading and re-sublimation because it blocks the contact between the recorded image (5) and the outside air. Effective in prevention.

Further, the coating layer (5) has a function of filling the irregularities of the fixing layer (2) and therefore prevents irregular reflection and also has a function of providing sharpness and glossiness of the thermal transfer image.

When a transparent polymer film is used as the support (1) according to the present invention, it has a good light-transmitting property because it has a function of becoming transparent after being film-formed by heat treatment after thermal transfer recording. It can be used for optical projection type recording media such as for overheads.

Furthermore, if a support having a surface such as a silk grain and a finely rough surface, which is known in the Photographic Industries Association, is used as the support, a surface corresponding to it can be obtained by the shape transfer action in the solidification process of the transparent layer (3) after heat melting. Further, when the transparent layer (3) is formed into a film, it can be a thermal transfer recording image having a molding surface and a smooth surface corresponding to it, if pressure-bonded to the molding surface or the smooth surface.

(F) Examples Hereinafter, examples of the present invention will be described, but the invention is not limited to these examples. The parts and% shown in the examples mean parts by weight and% by weight.

Example 1 Kayaset Blue 906 (Nippon Kayaku), Kasset Yellow AG (Nippon Kayaku), Kayaset Red B were used as dispersible sublimable coloring materials on a condenser paper having a thickness of 10 microns.
(Nippon Kayaku) 10 g each, Byron # 200 (Toyobo polyester resin) 3 g, Aerosil R-972 (Japan Aerosil hydrophobic silica) 2 g, toluene 63 g, methyl ethyl ketone 17 g are mixed and pulverized in a ball mill for 24 hours, and gravure printing is applied. It was applied so that the amount of work would be ² g / m ² , and dried to obtain each color material sheet.

As a support (1), Peachcoat WP-110 (Nisshinbo,
Using Synthetic paper, Bayronal MD-1200 (Toyobo, polyester resin aqueous dispersion 100g (solid content weight), Snowtex C (Nissan Chemical Co., colloidal silica) 150g (solid content weight) and Hydrin M-7 (Nikkyo) Oil and fat, stearic acid amide emulsion) 100g (solid content weight) are mixed and dispersed, smeared with an air knife coater to a coating amount of 4g / m ² , dried to form a fixing layer (2), and further heated. Prepare a coating liquid consisting of 20 parts (solid weight) of Chemipearl (polyethylene aqueous dispersion, Mitsui Petrochemical) as plastic organic polymer particles, 7 parts of polyvinyl alcohol adhesive (weight of solid content) as adhesive, and 40 parts of water. Then, on the fixing layer (2), the permeation layer (3) is applied so that the solid content is 2 g / m ^2.
Was applied and dried to obtain a thermal transfer recording image-receiving sheet.

Each color material sheet and the coating surface of the thermal transfer image receiving sheet are opposed to each other, and printing is performed from the back surface of the color material sheet with a thin film thermal head manufactured by Matsushita Electric Co., Ltd. As a result of transfer to the image receiving paper, high printing density is achieved. Excellent image quality was obtained.

Then, a thin polyethylene terephthalate film was superposed on the thermal transfer image-receiving sheet on which the thermal transfer recording had been carried out, and the mixture was passed through a heating and pressing device to form a coating of the permeable layer (3), whereby a recording sheet having a glossy surface was obtained.

The recorded image (5) of this recording sheet shows solvent resistance, light resistance,
The abrasion resistance was excellent, and satisfactory results were obtained in terms of color development and fading.

Example-2 1 g of the solid content of the permeable layer (3) was prepared by the same production method as in Example-1.
/ m ² and 5 g / m ² are provided, and similar thermal transfer recording,
As a result of conducting the coating test, in both cases, Example-
Good results similar to 1 were obtained.

Comparative Example-1 The solid content of the permeable layer (3) was adjusted to 0 by the same production method as in Example-1.
As a result of performing the same thermal transfer recording and film formation test as it was provided at 5 g / m ² , the image on the thermal transfer recording was as clear as or better than that of Example-1, but the film formation was not completely performed and the image was uneven. Therefore, the solvent resistance and the light resistance were not satisfactory.

Comparative Example-2 The solid content of the permeable layer (3) was 8 g by the same production method as in Example-1.
/ m ² and composed manner provided, similar thermal transfer recording, a result of performing the coating trials, was worse than in Example 1 in sharpness of the recorded image (5). The film was completely formed, but curling occurred.

Comparative Example-3 A fixing layer (2) was provided on the same support (1) as in Example-1 by the same method as in Example-1, and dried to obtain a thermal transfer image-receiving sheet. Thermal transfer recording was carried out in the same manner as in Example-1, and the thin polyethylene terephthalate film was superposed and passed through a heating and pressing device. The recorded image (5) on the obtained recording sheet was clear, but had no resistance to organic solvents, and gradually faded due to light irradiation.

(G) Effect of the invention The production conditions and results of the examples and comparative examples are summarized in the table.

As can be seen from the table, the solid content of the permeable layer is 1.0 g / m ²
If a sublimation type thermal transfer recording image receiving sheet up to 5.0 g / m ² is used, a clear recording image (5) can be obtained, and after the transmissive layer (3) is formed into a film, recording is excellent in solvent resistance, fading resistance, etc. A sheet is obtained. When the solid content of the permeable layer is less than the above range, the coating property is not sufficient and thus the solvent resistance and the color fading resistance are poor. When the solid content of the transparent layer is more than the above range, a clear recorded image (5) cannot be obtained during recording, and curling is remarkable even after forming a film. Further, the conventional type sublimation type thermal transfer recording image receiving sheet having no transparent layer (3) can obtain a clear recorded image (5), but is inferior in solvent resistance, discoloration resistance and the like and has a problem in long-term storage.

As described above, the sublimation type thermal transfer recording image-receiving sheet of the present invention is provided with the permeable layer (3) of the thermoplastic organic polymer fine particles so that a clear image can be formed at the time of recording without preventing permeation of the gaseous sublimable colorant. A sublimation type thermal transfer recording image-receiving sheet excellent in recording storability by dramatically improving functions such as solvent resistance and discoloration resistance by forming the permeable layer (3) into a film by heating / pressurizing after recording. Is provided.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing the structure of a sublimation type thermal transfer recording image receiving sheet comprising a support (1), a fixing layer (2) and a transmission layer (3). FIG. 2 is a schematic cross-sectional view showing the structure of a thermal transfer recording image-receiving sheet which has been heated / pressurized after recording. (1) ... Support (2) ... Fixing layer (3) ... Transmission layer (4) ... Coating layer

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yasuhiro Aizawa 1-4-1 Toganecho, Katsushika-ku, Tokyo Inside Central Research Laboratory, Mitsubishi Paper Mills (72) Inventor Kimei Seno 1-4-4 Toganecho, Katsushika-ku, Tokyo No. 1 Yasuko Eto, Examiner, Central Research Laboratory, Mitsubishi Paper Mills Co., Ltd. (56) Reference JP 59-222389 (JP, A) JP 59-214696 (JP, A)

Claims (3)

[Claims] 1. An image-receiving sheet used for sublimation thermal transfer recording, wherein the image-receiving sheet is a) a support, b) a fixing layer made of a resin layer having a good fixing property of a heat-sublimable coloring material, and c) provided on the fixing layer. A sublimation-type thermal transfer recording image-receiving sheet comprising a combination of a transparent layer which is substantially composed of thermoplastic organic polymer fine particles and which allows a thermally sublimable coloring material to pass therethrough and which can be formed into a film by heating / pressurizing. 2. The sublimation type thermal transfer recording image-receiving sheet according to claim 1, wherein the thermoplastic organic polymer forming the transparent layer is a thermoplastic polyolefin. 3. The sublimation type according to claim 1, wherein the coating amount of the thermoplastic organic polymer fine particles forming the permeable layer is 1 g / m ² or more and 5 g / m ² or less in terms of solid content. Thermal transfer recording image receiving sheet.