JPH0688480B2 - Transfer foil manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a thermal transfer foil used for surface decoration of a plastic molded product, and more particularly, to an uneven pattern composed of a highly sophisticated coating film on the surface of the transferred product. The present invention relates to a method for manufacturing a transfer foil intended to be formed.

(Prior Art) Conventionally, a transfer foil used for surface decoration of plastic products is formed by applying a surface protective layer made of a thermoplastic resin such as acrylic resin on the surface of a transfer foil substrate,
Generally, a pattern layer, a hiding layer, and an adhesive layer are sequentially formed, and therefore the surface hardness and durability of the final product were not sufficient.

Therefore, especially when scratch resistance of the surface is required,
There was no choice but to take the complicated process of applying an ultraviolet-curable transparent paint (so-called hard coat) on the surface of the transfer product.

Several methods have already been proposed for incorporating an ultraviolet-curable coating film into the transfer foil from the beginning.

However, the type of ink that gives sufficient adhesion to the UV-curable coating after curing is limited, so apply the UV-curable coating to the base film of the transfer foil and irradiate it with UV rays to cure it. After that, the transfer foil having practically sufficient adhesion could not be obtained by the method of successively forming the pattern layer, the hiding layer, and the adhesive layer.

(Problems to be Solved by the Invention) The present invention is intended to solve the above-mentioned drawbacks of the prior art, and is excellent in interlayer adhesion only by transferring in the same manner as a normal transfer foil. Another object of the present invention is to provide a method for producing a transfer foil capable of obtaining a transfer product having an uneven pattern having strong scratch resistance and abrasion resistance on the surface.

(Means for Solving Problems) Hereinafter, the method of the present invention will be described in detail with reference to the drawings.

First, as shown in FIG. 2, a heat-sensitive adhesive (2) is applied to the surface of a printing substrate sheet (1) having releasability, and then a hiding layer (3) and a pattern layer (4) are sequentially printed.

Since the base sheet is to be peeled and removed in a later process, it is desirable that the base sheet be as inexpensive as possible.
PET (polyethylene terephthalate) film, polypropylene film, polypropylene film laminated paper, etc. can be used.

As the heat-sensitive adhesive, an appropriate one such as acrylic resin, polyamide resin, ethylene vinyl acetate resin, wax, chlorinated polypropylene resin, vinyl chloride vinyl acetate copolymer resin, etc. is selected according to the material of the final transfer product.

The hiding layer and the pattern layer are selected in consideration of printability and adhesion to the ultraviolet curable resin used in the subsequent step. Acrylic resins, chlorinated rubber resins, vinyl chloride-vinyl acetate copolymer resins, etc. are common.

Next, as shown in FIG. 3, the surface of the printed sheet (5) obtained as described above was coated with the ultraviolet-curable coating material (6) and heated if necessary to remove the solvent component in the coating material. Then, after coating a PET film (7) with a thickness of about 25μ, PET
Ultraviolet rays are irradiated from the film surface to cure the coating material, and then the printing substrate sheet (1) is peeled off and removed to obtain a transfer foil as shown in FIG.

The UV-curable coating used here is preferably a high-hardness type of known acrylic oligomer-based UV-curable coatings.

A transparent raised pattern layer is formed in advance on the surface of the PET film used here in contact with the ultraviolet curable coating material.

The resin that forms the transparent raised pattern layer must be transparent to transmit ultraviolet light, have adhesiveness to the PET film, and have releasability to the ultraviolet curable coating film. Therefore, thermosetting polyester resin, polyamide resin, urethane resin and the like are suitable.

(Example) A heat-sensitive adhesive mainly composed of an acrylic resin is applied to the entire surface of a raw material obtained by laminating polypropylene resin on thin paper, and then a concealing layer is formed with a concealing ink corresponding to the solid color of a wood grain pattern. A wood grain pattern was printed on this.

For the hiding layer and the pattern layer, a vinyl chloride vinyl acetate copolymer resin-based ink was used.

5 g / m of acrylic resin-based UV curable paint (manufactured by Mitsubishi Rayon Co., Ltd.) on the surface of the printed sheet obtained as described above.
² was applied, in advance of a polyamide resin is coated PET film with a thickness of 25μ was formed a pattern layer raised by printing a grid pattern shape, curing the coating material over the by irradiating ultraviolet rays using a high pressure mercury lamp on the I'm sorry.

Next, the polypropylene resin laminated paper was peeled off and removed to obtain a desired transfer foil.

The transfer foil thus obtained was transferred to the surface of a polystyrene resin molded product using a rubber roll heated to 210 ° C, and the PET film was peeled off and removed, and the surface had excellent scratch resistance and good interlayer adhesion. In addition, a wood grain transfer product having a lattice-shaped concave-convex pattern formed on the surface and having an extremely high design effect was obtained.

(Effects of the Invention) Unlike the conventional transfer foil production, the method of the present invention applies an ultraviolet-curable coating material corresponding to a surface protective layer onto a print pattern layer previously formed on a releasable printing substrate sheet. Since it is subsequently irradiated with ultraviolet rays to be cured, the adhesion between the ultraviolet curable coating film and the pattern layer is good.

Further, since the PET film, which will be the base sheet of the transfer foil, is coated on the ultraviolet curable coating material, there is an effect that curing inhibition by oxygen does not occur. Further, since the surface protective layer of the transfer foil uses the ultraviolet curable coating material, it is possible to obtain a transfer product having a high design effect, which is extremely excellent in scratch resistance and abrasion resistance of the uneven pattern on the surface.

[Brief description of drawings]

The drawings are for explaining the present invention. FIG. 1 is a schematic view showing a step of peeling and removing a printed base sheet, FIG. 2 is a sectional view showing a constitution of a printed sheet, and FIG. It is a schematic diagram which shows the state. (1) …… Printing base sheet (2) …… Heat-sensitive adhesive (3) …… Hiding layer (4) …… Picture layer (5) …… Printed sheet (6) …… UV curable paint (7) ) …… PET film (8) …… Asperity pattern (9) …… UV irradiation device

Claims (1)

[Claims] 1. A method of manufacturing a transfer foil comprising the following steps. (1) A step of applying a heat-sensitive adhesive to a printing substrate sheet having releasability, and then printing and forming a hiding layer and a pattern layer. (2) An ultraviolet curable coating material is applied to the surface of the sheet obtained in (1), and then a transparent polyethylene terephthalate film having a transparent raised pattern layer previously formed on the surface thereof is faced downward. The step of coating and irradiating ultraviolet rays on the coating to cure the coating material. (3) A step of peeling and removing the printing substrate sheet having releasability.