JPH0253109B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a sharp emboss, and more specifically, a pattern is printed on a base material using liquid-repellent ink, a transparent resin is coated on top of the pattern, and then solidified to form a pattern. In a method for manufacturing a decorative material having a synchronized concave surface, a curable resin that is inhibited by air from curing is used, only the surface layer is left uncured, and then an air-blocking film or the like is covered to completely cure the resin. The present invention relates to a method for forming a sharp emboss.

Conventionally, as a method of so-called synchronized embossing that has unevenness that is synchronized with the pattern, a part of the ink printed on the base material is used to repel the top coat resin, and then the top coat resin is applied in liquid form. A method has been proposed in which the resin is coated in this state and then solidified so that a portion of the top coat resin in the pattern becomes a recess. This method has the advantage that not only can a wide range of top coat resins be applied relatively easily, but also the unevenness itself can be made larger compared to a method that uses the difference in curing shrinkage of the top coat resin. Therefore, the shape of the outer edge of the recess is not sharp, leaving a visually so-called edged feeling, and when applied to a wood grain pattern, etc., it has the disadvantage that it is far from expressing the wood texture. It was hot.

As a way to improve and alleviate this drawback,
Conventionally, there have been methods to remove the gloss of the surface coating resin to reduce the reflection of light at the edges and make it visually less noticeable, and to reduce the fluidity of the coating resin to prevent the resin surface from equilibrating after repelling. Methods such as solidifying the liquid-repellent ink and adjusting the gloss of the liquid-repellent ink to make the edges less noticeable have been used, but none of these methods can be expected to be sufficiently effective.
In the third method, there was a problem of limited gloss, and in the second method, there was a problem of coating suitability, which was difficult to solve.

In order to improve the above-mentioned drawbacks, the present inventors first
After curing, we tried applying heat and pressure using an embossing plate to smooth the surface and crush the bulges in the resin around the edges. Although this method was effective to some extent depending on the hot pressure conditions and the gloss of the surface of the embossing plate, it was found that there is a limit to the embossing after the curable resin has been cured.

Next, the inventors increased the viscosity of the top coat resin.
Attempts were made to smooth the surface and further shrink the edges by bringing the embossing plate into contact with the embossing plate in a state where fluidity was reduced by slightly advancing the curing process. Although this method was effective in some cases in the laboratory, the embossing plate could not be released smoothly until after the resin had hardened, and the method of increasing resin viscosity had the same drawbacks as the conventional method described above. However, with the method of slightly advancing curing, it was difficult to control the degree of curing.

On the other hand, the present inventors used the film method normally used in the production of polyester decorative plywood, that is, applying unsaturated polyester resin in liquid form to the base material surface, then covering the surface with nylon film, vinylon film, etc., and degassing it. At the same time, we attempted to apply a method for removing the film after waiting for the resin to harden for this purpose. That is, this is a method in which a film is brought into close contact with the top coat resin when its fluidity is high, and the film is removed after curing, thereby eliminating edges and creating a smooth surface with the gloss of the film transferred thereto. This method does not substantially require heat pressure for embossing, so there is little deformation due to these factors, but because the resin has high fluidity, the film must be stuck statically and uniformly, and it can be applied over a large area. It was difficult to maintain this over time.

From the above study results, in order to obtain sharp unevenness by synchronized embossing using liquid-repellent ink, the resin layer must be solidified to some extent after the unevenness is formed, and the surface can be easily deformed with an embossing film, etc. As a result of various searches for such conditions, the present inventors discovered that the phenomenon of inhibiting the curing of radically polymerizable resins by oxygen can be used for this purpose, and completed the present invention. Reached.

That is, as described in the claims, the present invention uses a curable resin that is inhibited by surface curing by air (oxygen) as the top coat resin, and performs the initial curing with the surface exposed to air. By stably creating a cured state in which only the resin layer is uncured and easily deformable, and then covering this with an air-blocking film, belt, drum, etc., and curing it further, the surface layer is also included. This is a method for forming a sharp embossed surface that completely cures the top coat resin layer, has very little fringing at the outer edge of the liquid-repellent ink, and has a smooth surface where the surface gloss of the coating has been transferred.

The top coating resin used in the present invention may be any radically polymerizable resin that is inhibited by air from curing, and unless it is completely air-dryable, unsaturated polyester resins, (meth)acrylic ester oligomers, Curable acrylic resins mainly composed of monomers, modified products thereof, dialphthalate resins, etc. can be used. There are no particular limitations on these curing methods, including thermal curing using a radical polymerization initiator, room temperature curing using a redox catalyst,
Any method such as ultraviolet curing using a photopolymerization initiator or electron beam curing can be used.

The air-blocking material may be one that can be brought into contact with the surface of the uncured resin and can be peeled off after curing, such as plastic films such as polyester film, polypropylene film, nylon film, vinylon film, or sheet-like materials such as release paper. It may be made of glass, metal, etc. in the shape of a belt, drum, etc., but depending on the curing method, for example, in the case of an ultraviolet curable top coat resin, a transparent material is preferable. Furthermore, since these surface shapes are transferred to the surface of the cured resin layer, they may be matte or otherwise processed.

The liquid-repellent ink may be of any known type, and is usually an ink containing silicone oil, a fluorine compound, etc., and may optionally be made matte to emphasize the unevenness.

Examples are given below, but the present invention is not limited to these unless it departs from the spirit thereof.

Example 1 A 0.15mm thick semi-rigid colored PVC sheet was coated with salt-vinyl acetate/
A base material was created by gravure printing a wood grain pattern using an ink containing an acrylic copolymer as a binder. At this time, apply dimethyl silicone only to the conduit handle.
The final printing was done using ink containing 10%. A 20μ thick layer of ultraviolet curable acrylic resin was coated on top of this, and a medium pressure mercury lamp with an output of 80W/cm was used to
of polypropylene after irradiation at a speed of m/min.
A 25μ thick pine film was adhered from above, and the same mercury lamp was passed twice at a speed of 10 m/min, and then the pine film was peeled off.

As a result, an elegant woodgrain sheet having a transparent resin layer on the pine surface with sharply concave conduit portions was obtained.

Example 2 A 60 g/m ² resin-reinforced colored paper was coated with an anti-penetration sealer, and a wood grain pattern was gravure printed on it using a binder ink such as nitrocellulose, and only the conduit pattern was coated with an ink containing 15% dimethyl silicone. Decorative paper was created using this method. This decorative paper was attached to 2.7 mm thick lauan plywood with a vinyl acetate adhesive, and unsaturated polyester resin was applied to the surface using a flow coater to a thickness of 25 μm. After 10 minutes, a vinylon film with a frame was placed on it, left at 40°C for 24 hours, and then the film was peeled off. As a result, a polyester decorative plywood having a surface in which the conduit portion was sharply concave was obtained.

[Brief explanation of the drawing]

The drawings show an example of the method of the present invention, and FIGS. 1 and 2 are cross-sectional views showing the state of the liquid resin coated on the liquid-repellent ink, and FIG. 1 shows the viscosity of the liquid resin. Figure 2 schematically shows the case where is relatively high, and the case where it is low. Figure 3 shows a state in which a resin that is inhibited by air curing has been applied and partially cured by exposing it to air, Figure 4 shows a state in which a film is covered with it, and Figure 5 shows a state in which the film is peeled off after complete curing. FIG. 3 is a cross-sectional view schematically showing each state. 1... Base material, 2... Ordinary printing ink layer or base material, 3... Liquid repellent ink layer, 4... Top coat resin layer (before curing), 4'... Top coat resin layer (uncured portion),
4″...Top resin layer (cured portion), 5...Air-blocking film.

Claims (1)

[Claims] 1. Printing a pattern on a base material using liquid-repellent ink,
In this method, a curable resin that is inhibited by air from curing is used as the top coat resin, and the curable resin is After curing in contact with air to leave only the surface layer in an uncured state, pressurize the uncured resin part with an air-blocking film, belt, drum, etc. to form a curable resin layer. A method for forming a sharp embossment, which is characterized in that the surface of the resin is coated so as to be flat, and the uncured resin portion is cured in that state. 2. The method according to claim 1, wherein an ultraviolet curable resin or an electron beam curable resin is used as the top coat resin.