JPS5921796B2 - dry heat transfer paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dry heat transfer paper used for painting on glass, ceramics, etc.

Glass and ceramics are one of the methods of painting on glass and ceramics.
There is a method of transferring ink to the wall of ceramics, etc., and then firing it.

In this method, an ink consisting of a pigment, a flux (low-melting glass frit), and a dispersion medium is applied to the transfer surface of glass or ceramics by transfer, and then baked to fix the ink.

However, in the painting process of transferring and firing, air bubbles may be trapped between the transferred surface and the transfer object during the transfer, or resin contained in the ink etc. may evaporate during the baking, leaving traces. Pinholes may remain in the painted design, such as remaining until after firing.
This was a major obstacle when attempting to create delicate designs on glass or ceramics.

The present invention is an attempt to solve the above-mentioned problems, and as a result of intensive efforts, we have arrived at the invention of a dry thermal transfer paper as described below.

The feature of the dry heat transfer paper of the present invention is that by eliminating the peeling layer made of resin that melts when heated, which was found in conventional dry heat transfer paper, the amount of unnecessary resin transferred to the transfer surface is reduced. In addition, the adhesive layer for transferring the ink layer contains a resin that prevents the design from flowing during the firing process, a large amount of plasticizer that prevents air from being trapped during the transfer process, and a large amount of plasticizer that prevents the drawing from drawing in during the transfer process. This includes using a resin that becomes sticky when heated to improve its adhesion.

The dry heat transfer paper of the present invention will be explained below.
The figure shows a cross-sectional view of one embodiment of the transfer paper of the present invention. In the figure, the base sheet 1 is subject to expansion and contraction due to drying during printing, changes in temperature and humidity during storage, and heating temperature during transfer. This method uses a material with stable properties that does not cause such problems.

As long as the above properties are satisfied, paper, metal foil, plastic sheet, etc. may be used alone or in a laminate. A film layer 2 of a polyolefin resin is applied to the surface of the base sheet 1 as described above to form a transfer paper base, and on top of the film layer 2 of the transfer paper base, an ink layer 3 to be transferred and the ink layer 3 to be transferred are coated with heat. Adhesive layer 4 that adheres to the transfer surface
The transfer paper of the present invention is provided with: Below, each layer of the transfer paper of the present invention will be explained in detail.
The film layer 2 releases the ink layer 3 during transfer due to the inertness of its surface, and is made of, for example, a polyolefin resin film.

Considering the heat resistance required during thermal transfer, it is better to use a polypropylene film than a polyolefin film. Next, regarding the ink layer 3, the ink used here consists of a pigment (metal oxide or other heat-resistant inorganic pigment), a flux (a frit of low melting glass), and a dispersion medium.

Various types of pigments and fluxes currently available on the market can be used. As the dispersion medium resin, nitrocellulose, ethylcellulose, vinyl resin, acrylic resin, petitral resin rosin, maleic acid resin, etc. can be used, but they are important in terms of printability and the final finish after firing, especially in preventing the formation of pinholes. Acrylic resin is particularly suitable as a dispersion medium resin with a low residual ash content. Each of the above-mentioned resins is used alone and made into a varnish with a solvent to be used as a dispersion medium. Examples of typical ink compositions are shown below.

All are weight ratios. As the acrylic resin, Aron resin manufactured by Toagosei Kagaku, Palide resin manufactured by Rohm and Haas, Dianal resin manufactured by Mitsubishi Plastics, etc. can be used.

The ink layer 3 is formed by applying the ink composition as described above onto a desired pattern by screen printing or the like. next,
Regarding the adhesive layer 4, it is the most important layer because it firmly adheres to the transfer surface of glass or ceramics and transfers the ink layer 3.

Conventionally, this type of dry thermal transfer paper often has an adhesive layer mainly made of thermoplastic resin, but during the transfer process, air is trapped between the glass surface and the adhesive layer.
Air bubbles are generated, and the air bubbles cause pinholes to occur during the firing process. The reason why pinholes are likely to occur in the dry transfer method is largely due to poor adhesion to the glass surface during the transfer process, so care must be taken.

From the above, the adhesive layer 4 consists of a resin that prevents the pattern ink from flowing during the firing process, a large amount of plasticizer that prevents air from being trapped during the transfer process, and a bond that adheres to glass and ceramics using heat. It is mainly made of resin that gives it properties. Nitrocellulose, ethylcellulose, and the like are good resins for preventing the pattern from flowing during firing; these resins hardly soften at the temperature during the transfer process, and therefore do not contribute to adhesion to glass. Phthalate ester plasticizers, phosphate ester plasticizers, and other diphenyl derivatives are suitable as agents to prevent air entrainment during the transfer process, and the amount of these added should be adjusted relative to the above-mentioned ditrocellulose resin and ethyl cellulose resin. Add about 20 to 100% by weight. These plasticizers rise to the surface due to the heat during the transfer process, resulting in very good wettability to the transfer surface, and have the effect of expelling the air inside to the outside to eliminate air bubbles.
Examples of resins that become sticky when heated include tackifier resins such as various rosins and ester gums. The amount added is 20% or less by weight relative to nitrocellulose and ethylcellulose resin.
In order to transfer onto glass or ceramics using the transfer paper of the present invention, the transfer paper is applied to the surface of the object to be transferred which has been heated beforehand, and if necessary, the transfer paper itself is also heated.

That is, the adhesive layer 4 in close contact with the surface to be transferred is activated by heat and becomes sticky, and together with the ink layer 3, is transferred to the object to be transferred and transferred. At that time, the film layer 2 made of polyolefin resin is not activated by heat,
The ink layer 3 and the film layer 2 are easily separated and peeled off.
According to the dry heat transfer paper of the present invention, since bubbles are not generated during transfer and pinholes are removed during firing, beautiful and delicate designs can be applied to glass, ceramics, etc.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view showing an example of the dry thermal transfer paper of the present invention. 1... Base sheet, 2... Film layer, 3... Ink layer, 4... Adhesive layer.

Claims (1)

[Claims] 1. A dry heat transfer paper comprising a release layer, an ink layer, and an adhesive layer on one side of a base sheet, the adhesive layer comprising a resin made of nitrocellulose or ethyl cellulose, a resin made of rosin or ester gum, and a plasticizer. A dry heat transfer paper characterized by: