JPH0410072Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a transfer sheet, and particularly to a transfer sheet that exhibits its effect on a transfer sheet printed with a line image of 100 μm or less using ink containing a sublimable dye.

<Prior art> Dyes that sublimate, vaporize, or transfer by heat melting are known as sublimation dyes, and a transfer sheet made by printing an ink containing this dye on a suitable base sheet can be printed on cloth or plastic. The method of thermally transferring the material by adhering it to the molded product is known as the sublimation transfer method. This transfer method is useful, for example, for printing characters and symbols on the keys of a keyboard.The transferred dye penetrates into the inside of the plastic key, so even if the button is pressed many times, the pattern will not wear out.
It has the advantage of not falling off.

By the way, the image transferred to this key is
Usually, it is a line image of characters, symbols, etc., but the ink containing the above-mentioned sublimable dye is printed on the base sheet by gravure, offset, or silk screen, and non-image areas due to ink splatter during printing The drawback is that the stains are reproduced directly on the transferred material. And this dirt is surprisingly common.

A possible method for preventing this is, for example, to print an ink containing a sublimable dye on the entire surface of the base sheet, leaving only the image area, and printing with a resisting ink that prevents the penetration of the dye. However, resist printing ink does not exhibit a good resist printing effect unless it is printed to a film thickness of about 2 μm after drying. The line image will be interrupted, or even if it is not interrupted, the lines will become thin.

<Problems to be solved by the invention> The present invention was developed in view of the above-mentioned circumstances, and it has the following problems: stains in non-image areas are not reproduced on the transferred object, and line images are interrupted or become thin. The purpose is to provide a transfer sheet that will never be damaged.

<Means for solving the problem> In order to solve this problem, the present invention prints an image on a base sheet using ink containing a sublimable dye, and creates a 500 μm or less distance around the image. To provide a transfer sheet printed with resisting ink that prevents the transmission of a sublimable dye with or without providing it.

<Function> In the transfer sheet of the present invention, since the non-image area is covered with resisting ink, the sublimation dye stains attached thereto are not transferred to the transfer object and are not reproduced.

Ideally, there should be no gap between the image created by the ink containing sublimable dye and the resist ink, but it is necessary to precisely control the misregistration of these two inks and the flow of the resist ink. Since it is difficult to do so, there may be a slight gap between the two. This is what is meant by 500 μm or less, and even if there is a distance of this extent, stains caused by this will hardly occur.

Also, when printing, resist ink may stain image areas due to splashes, etc., but since line images generally have a smaller area than non-image areas, the rate at which this resist ink stains image areas is low. In addition to being small, as mentioned above, the resistance ink does not exhibit its ability to resist unless the thickness is 2 μm or more, whereas stains caused by splashes, etc. do not reach 1 μm, so stains from this resist ink can damage the image. There are no white spots in the area. In addition, sublimable dyes are transferred while being diffused, so even if there is a small amount of resist ink, like a pinhole, in an image made with ink containing sublimable dyes, this will be removed by the diffusion of the surrounding dye. Since the pinhole disappears from the transfer object, stains caused by resisting ink are not reproduced on the transfer object from this point of view as well.

<Example> The present invention will be described below with reference to the drawings. The drawings show an embodiment of the present invention, and FIG. 1 is an explanatory sectional view of the transfer sheet.

In FIG. 1, 1 is a base sheet, 2 is an ink containing a sublimable dye (hereinafter referred to as "sublimable ink"), 3 is a resist dyeing ink, and 21 and 31 are shown for convenience of explanation. 21 is a sublimation ink stain, and 31 is a resist ink stain.

Any material such as paper, metal foil, plastic film, etc. can be used as the base sheet 1. For example, if the object to be transferred is a keyboard key, the surface of the object to be transferred is a curved surface, so it must have enough elasticity to adhere to the curved surface. What you have is good. Generally, a plastic film such as a polyester film or a film whose surface is resist-dyed with polyvinyl alcohol or the like is used.

The sublimable ink 2 contains a binder and other additives in addition to the sublimable dye, and further contains a solvent during printing. All of these are well known; for example, sublimable dyes include disperse dyes and oil-soluble dyes, and binders include cellulose binders. The solvent may be water, a hydrophilic organic solvent such as alcohol, or a hydrophobic organic solvent. A specific example is an ink consisting of a sublimable disperse dye, a binder made of an acrylic acid ester copolymer, and a solvent made of a mixture of water and alcohol.

The resist ink 3 is also well known, and in addition to physical resists such as acrylic ester copolymers and activated carbon, chemical resists such as stannous chloride are known. These resist dyes may be dissolved or dispersed in a solvent to form an ink. Note that it is advisable to mix colored pigments into the ink so that the printed areas can be visually observed.

The sublimation ink 2 can be printed by gravure, offset, or silk screen printing methods, but since resist ink needs to be printed to a thickness of 2 μm or more, it is preferable to print by silk screen or gravure.

21 is a stain caused by the sublimation ink, but this is naturally blocked by the resist dyeing ink 3 and is not transferred. Also, 31 is a stain caused by resist dyeing ink,
As explained in the Effects section, this does not interfere with transcription.

<Effects> With the transfer sheet of the present invention, stains in non-image areas caused by ink containing sublimable dyes will not be reproduced on the transferred object, and line images will not be interrupted or thin. This has the effect of reducing the defective rate.

Note that this invention is not limited to line image transfer sheets;
It is clear that the same effect can be obtained even with a transfer sheet for a surface image.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is an explanatory cross-sectional view of a transfer sheet. 1... Base sheet, 2... Sublimation ink, 3
... Resistance ink, 21 ... Stain by sublimation ink, 31 ... Stain by resistance ink.

Claims (1)

[Scope of utility model registration request] A base sheet, a line image created by ink containing sublimable dye provided on it, and the area around the line image.
A transfer sheet consisting of a printed layer of resist dye ink that prevents the transmission of sublimable dyes and is formed with a gap of 500 μm or less.