JPS629990A - Thermal transfer recording method - Google Patents

Abstract

PURPOSE:To make it possible to form a sharp recording image having no blur, as a gas dye permeable thin film to which an original image due to a heat- sublimable or heat-evaporative dye is provided, by using one having large number of fine pores piercing therethrough in the direction at a right angle to the surface thereof. CONSTITUTION:A original image 3 due to to a heat-sublimable or heat- evaporative dye is formed to one surface of a gas and dye permeable thin film 6 having a large number of fine pores 2 piercing therethrough in the direction at a right angle to the surface thereof and a gas and dye transmission preventing layer 4 is provided thereon to form a transfer sheet. A receiving sheet 5 is superposed to the surface having no original image of the transfer sheet to perform thermal transfer and a positive transfer image is formed on the receiving sheet 5. The sublimed or evaporated dye at the time of thermal recording transmits through the film in the direction at a right angle to the surface thereof to be received by the receiving sheet 5 without diffusing to the surface direction by independent piercing pores 2. By this method, a sharp transfer image free from the diffusion of the evaporated dye and, therefore, having no blur can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a thermal transfer recording method for obtaining a normal transferred image using a heat-sublimable or heat-vaporizable dye.

[Prior art]

Conventionally, a transfer sheet is created by forming an original image on one side of a thin film that is permeable to gaseous dye using a heat-sublimable or heat-vaporizable dye, and then providing a thin film to prevent gaseous dye permeation on top of the dye image. A receiving sheet such as paper or plastic film is placed on the side of the transfer sheet that does not have the original image, and thermal transfer is performed.The dye is vaporized and passes through the thin film of the transfer sheet, and then transferred onto the receiving sheet. A thermal transfer recording method for forming a normal transferred image is known.

According to the thermal transfer recording method as described above, although a normal image can be formed on a receiving sheet with a simple operation, there is a problem in that the image blurs and it is difficult to obtain a clear recorded image.

〔the purpose〕

The present invention aims to overcome the aforementioned drawbacks found in the prior art.

The inventors of the present invention have conducted extensive research to solve the above-mentioned problems, and have discovered that the blurring of images is caused by the pore structure of the thin film that is permeable to gaseous dyes.

In other words, thin paper and cloth have been proposed as conventional thin films, but the pores in such thin films are not independent but communicate with each other in a matrix shape, and therefore, gaseous dyes are absorbed by the thin film. It was found that as a result of diffusion in the surface direction of the receiving sheet, bleeding occurred in the transferred image on the receiving sheet.

〔composition〕

According to the present invention, an original image of a heat-sublimable or heat-vaporizable dye is formed on one side of a gas dye-permeable thin film having a large number of pores penetrating perpendicularly to the surface, and then A layer provided with a gas dye permeation prevention layer is used as a transfer sheet, and a receiving sheet is placed on the side of the transfer sheet that does not have the original image, and thermal transfer is performed to form a normal transferred image on the receiving sheet. Provided is a thermal transfer recording method characterized by:

In the present invention, a film having a large number of pores penetrating perpendicularly to the surface is used as a gas dye-permeable film for providing an original image using a heat-sublimable or heat-vaporizable dye. The attached drawing is a schematic cross-sectional view of such a thin film, and in the figure, 1 is a membrane material constituting the thin film 6, 2 is a pore penetrating perpendicularly to the surface of the membrane, and 3 is a thermal sublimation or hot air 4 is a blocking layer for preventing the transmission of gaseous dyes, and 5 is a receiving sheet. Since the pore structure of the thin film is as shown in the figure, the dye that sublimes or vaporizes during thermal recording does not diffuse in the plane direction due to each independent through hole 2, but passes through the membrane in a direction perpendicular to the plane and faces the opposite side. is received on a receiving sheet.

Such a thin film is preferably one that is heat resistant and does not allow the vaporized dye to pass through itself (that is, does not allow the vaporized dye to pass through except through the through holes), such as tetrafluoroethylene resin, gelatin, polyimide resin, etc. , cellulose resin, etc. are preferably used. The diameter of each through hole 2 is preferably in the range of 0.1 to 10 μm, and the thickness of the membrane is preferably in the range of 20 to 200 μm. Filters commonly used for filtration, for example, commercially available filters with slag properties can be used.

As the heat-sublimable or heat-vaporizable dye, various conventionally known dyes can be used, and for example, dispersed monoazo dyes, dispersed anthraquinone dyes, etc. are preferably used.

To form images such as letters and patterns on the transfer sheet support thin film, a coating solution obtained by dispersing the dye in a dispersion medium is applied onto the thin film, and the coating solution is applied at a temperature below the sublimation or vaporization temperature of the dye. dry. In this case, this coating liquid may contain
Adhesive substances such as starch, gum arabic, methylcellulose, carboxymethylsemerose, polyvinyl alcohol, monohelium arginate can be added as binders. The proportion of this binder used is preferably in the range of 0.05 to 1.0 parts by weight per 1 part by weight of the dye.

In addition, the coating liquid may further contain a conventional dispersant (surfactant) such as that used in dyes for synthetic fibers, if necessary.
can be added in a proportion of 0.3 to 2.0 parts by weight per 1 part by weight of the dye. Furthermore, fillers (for example, silica, calcium carbonate, alumina, clay, etc.) may be added in an amount of 0.5 to 1.0 parts by weight per part by weight of the dye. The amount of the image attached to the thin film for the support is 0.5 to 15 g/rr in terms of the amount of dye attached. (based on dye adhesion area).

The receiving sheet to which the dye that passes through the support thin film of the transfer sheet is attached may be any material having a solid surface, such as cloth, paper, plastic film, etc.

For the dye permeation prevention layer to be attached to or in close contact with Coe 1 on the heat sublimable coloring dye-containing layer, any resin that is not breathable, does not allow sublimation color dyes to pass through, is highly heat resistant, and does not adsorb sublimation dyes may be used. For example, polyvinyl alcohol, polyimide, epoxy, silicone, fluororesin, gelatin, etc. are suitable.

Next, the present invention will be explained with reference to the drawings. An original image 3 of letters, patterns, etc. is applied to one side (the side irradiated with light) of a gas dye-permeable thin film 6 for a support using a heat sublimable or heat vaporizable dye.
Write or print. Next, a dye permeation preventing layer 4 is provided, while a receiving sheet 5 is placed on the other side of the thin film 6 and heated. As a result, the dye of the original image 3 is heated to cause sublimation or vaporization, and the vaporized dye adheres to the receiving sheet 5 through the through holes 2 of the thin film 6, forming a normal transferred image. If only the receiving sheet 5 is replaced one after another and similar thermal transfer is performed, a large number of copies can be obtained. As a heat source used to provide the heat necessary for heating the dye, a white lamp containing infrared rays, an infrared lamp, a xenon lamp, a single-mouth flash lamp, a xenon flash lamp, etc. are used. In this way, heating is performed using P1 in addition to light irradiation.
- You may use a roller or a plate.

〔effect〕

According to the present invention, by using a thin film on the transfer sheet 1 having buttonholes penetrating in a direction perpendicular to the surface, there is no diffusion of vaporized dye, and therefore a clear transferred image without bleeding can be obtained. be able to.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Sublimation dye [:Kayasel; Red 026 (manufactured by Nippon Kayakurei)] 110 parts by weight Silica 10
〃Methyl cellulose 5% aqueous solution 20 n water 60
The composition consisting of 50% was dispersed in a ball mill for 2 hours.

This dye dispersion was applied to a vaporized dye permeable thin film made of polytetrafluoroethylene (PTFIE type membrane filter manufactured by Toyo Roshi 011) at a dry weight of 13 g/♂.
The letters were formed so that

Next, an aqueous methylcellulose solution was applied onto the letters so that the dry adhesion amount was 20 g/m.

When the surface opposite to the image forming side of the transfer sheet 1 obtained in this manner was placed on top of the receiving sheet (50 g/rrf high-quality paper) and irradiated with a 500mm infrared lamp for 10 seconds, the surface of the receiving sheet was It was possible to obtain a clear normal image without blur with an image density of 0.88.

Comparative Example 1 A normal transferred image was obtained on a receiving sheet in the same manner as in Example 1 except that 25 g/rrr type paper was used as the vaporized dye permeable thin film. The image density was 0.74, and some bleeding was observed.

Comparative Example 2 A normal transferred image was obtained on receiving sheet 1-1 in the same manner as in Example 1 except that cotton cloth was used as the vaporized dye permeable thin film. Although the image density was 1.01, there was significant bleeding.

[Brief explanation of the drawing]

The drawings are explanatory diagrams for implementing the method of the present invention. ]...Membrane material, 2...Through hole, 3...Original image, 4
... Dye permeation prevention layer, ... Receptive sheet. 6... Gaseous dye permeable thin film.

Claims (1)

[Claims] (1) An original image of a heat-sublimable or heat-vaporizable dye is formed on one side of a gas-dye-permeable thin film having a large number of pores penetrating perpendicularly to the surface, and a gas-dye is applied on the original image. A transfer sheet provided with a transmission prevention layer is used as a transfer sheet, and a receiving sheet is placed on the side of the transfer sheet that does not have the original image and thermal transfer is performed to form a normal transferred image on the receiving sheet. A thermal transfer recording method.