JPH0367750B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a decorative sheet that is excellent in water resistance, heat resistance, and flexibility, and has concave portions that match the printed pattern.

[Conventional technology]

A chemical that generates decomposition gas when heated is mixed into the ink, and after printing a pattern on the base material with the ink, a paint containing a hardening agent is applied on top of it and heated. A method for producing a decorative body in which the decomposed gas generated by the decomposition gas is captured in the coating film to form convex portions, and then the coating film tank of the convex portions is ground to form concave portions that are completely in sync with the printed surface is particularly developed. Kosho 54-
It is disclosed in Publication No. 11818.

[Problem that the invention seeks to solve]

In the above-mentioned method of manufacturing a cosmetic body, a condensation polymerization type resin paint such as aminoalkyd, melamine, or benziguanamine has been used as a paint that is applied onto the printed pattern to trap decomposition gas. The reason for this is that with cross-linked or addition polymerized resins such as urethane, polyester, and acrylic, the resin in the foamed parts does not become sufficiently brittle, and gets entangled with the parts to be ground such as bubbles during the grinding process, making it impossible to grind them thoroughly. be.

However, decorative sheets manufactured using condensation polymerization resins tend to curl and tear easily due to their lack of flexibility, and the curing catalyst acid remains in the paint. When adhering to other substrates or the like, there are problems such as heat-pressing, which produces a glossy finish on the decorative surface and also generates a pungent odor of formalin gas.

Therefore, when manufacturing such decorative sheets,
This technical field aims to solve the above problems by using crosslinked or addition polymerized resin paints in place of the conventionally used condensation polymerized resins, and to produce decorative sheets with excellent properties. This was an extremely important issue to be solved.

[Means for solving problems]

This invention involves printing patterns on the surface of a sheet using ink mixed with a chemical that generates decomposition gas when heated, and then adding unsaturated polyester resin and isocyanate to saturated polyester resin on top of the printed pattern. The mixed paint is applied and heated at a temperature at which the chemical rapidly decomposes to decompose the chemical and dry and harden the paint, and the decomposed gas generated in this process raises the paint applied on the printed pattern. The above-mentioned problem was solved by forming a convex portion using the ink and then grinding the convex portion to expose the ink surface.

In this invention, a paint made of a mixture of saturated polyester resin, unsaturated polyester resin, and isocyanate is used, and the reason for drying at high temperatures is to rapidly decompose the chemicals in the ink and generate gas, and at the same time, the unsaturated polyester resin and isocyanate to form a hard and brittle foamed coating while trapping gas in the coating, and also cross-linked with saturated polyester resin using heat to make it strong and flexible. The purpose is to form a coating film.

The sheet-like material used in this invention has a weight of
Paper or synthetic paper with a thickness of about 20 to 80 g/ ^m2 , or
It is a synthetic resin film of about 0.05 to 0.5 mm,
In particular, thin paper having a weight of 23 to 50 g/m ² is suitable because it is not only inexpensive but also has a smooth surface and is suitable for printing.

Next, a pattern is formed on the upper surface of the sheet by printing two to three layers of ink using a conventional gravure printing device or the like. At this time, a chemical that generates an excuse gas with heat is added to the ink only in the areas where it is desired to express concavities in the form of patterns such as wood grain conduits and grooves.

Agents that generate excuse gas with heat include benzenesulfonylhydrazide, toluenesulfonylhydrazide, azobisisobutylnitrile, diazoaminobenzene, acetone-P-toluenesulfonylhydrazide, 2,4-toluenedisulfonylhydrazide, and P-methylurethanebenzene. Sulfonyl hydrazide, N,N'-dimethyl-N,N-
Examples include dinitrosoterephthalamide and dinitrosopentamethylenetetramine (DPT).

In other words, it is known that the above chemicals decompose when heated and generate nitrogen gas, carbon gas, etc., and this decomposed gas is used to reduce the paint film applied to the top surface of the ink. to raise it.

The amount of the agent added to the ink should be within the range of 20 to 50 parts by weight per 100 parts by weight of the ink, which is a necessary and sufficient amount to cause the coating film to rise due to the decomposition gas generated from the ink. and desirable.

Next, a paint mixture of saturated polyester resin, unsaturated polyester resin, and isocyanate is applied to the entire surface of the above printed pattern. At that time, by adding a small amount of mold release agent such as silicone resin to the paint,
It is possible to improve the peeling resistance of the coating film due to cellophane adhesive tape, and to adjust the gloss of the coating film by adding an extender pigment.

The saturated polyester resin used in this action has an average molecular weight of 2000 to 3000, an acid value of 5 to 5.5,
It is a resin liquid with an OH value of 90 and a solid content of about 45%.
The unsaturated polyester resin mixed with the above resin liquid has an average molecular weight of 2000 to 3000 and an acid value of
10~20%, a resin liquid for coatings with a solid content of about 70%.

Normally, in the case of decorative paper with a smooth surface, the amount of paint applied is about 5 to 8 g/m ² , but in the present invention, a paint with a high resin solid content is used. This requires a coating amount of 13 to 20 g/ ^m2 , which is much higher than usual, as the decomposition gas must be captured by the coating film. This is to reduce penetration to the back side of the paper.

Furthermore, the isocyanate added to the above coating material mainly undergoes a crosslinking reaction with the unsaturated polyester resin to form a coating film.

The amount of each added is 80 to 110 parts by weight of the unsaturated polyester resin and 50 parts by weight of the isocyanate to 120 to 170 parts by weight of the above saturated polyester resin.
~60 parts by weight.

Then, the applied paint is rapidly heated above the decomposition temperature of the chemical to generate decomposed gas, and at the same time, while promoting the curing reaction of the polyester resin, the decomposed gas raises the paint on the top of the printed pattern and creates convex parts. Form. As a chemical, it promotes not only the reaction between unsaturated polyester resin and isocyanate, but also the crosslinking reaction between polyester resins.
A drug that decomposes violently at a high temperature of 150°C or higher, preferably 200°C or higher is more preferably used.

To grind the convex parts where the paint film has foamed and raised, use a high-speed rotating buff with abrasive grains of about 150 grit attached to the polishing roll to lightly polish the surface of the sheet. It can be easily removed to form a recess.

Incidentally, the decorative sheet of the present invention may be further coated with a commonly used transparent top coat on its upper surface.

〔Example〕

Example 1 A wood grain pattern was printed on thin paper weighing 23 g/m ² using a gravure printing machine. A commonly used gravure leaf ink was used as the printing ink, but a printing ink with the following formulation was used only for the wood grain pattern conduit grooves.

Cellulose type resin 50 parts Pigment 30 parts Solvent 50 parts Toluenesulfonyl hydrazide 40 parts Next, a transparent paint of the following composition was applied to the entire surface of the printing paper and dried at 210°C for 30 seconds to foam and harden the paint film. Ivy. The amount of paint applied is 15
g/ ^m2 .

Saturated polyester resin 150 parts Unsaturated polyester resin 100 parts Isocyanate 50 parts Solvent appropriate amount Thereafter, the foamed convex portions of the coating film were ground with a No. 150 buff to produce a decorative sheet having concave portions that matched the conduit pattern.

The decorative sheet was flexible and adhered integrally to the U-shaped chamfered substrate, but no tearing or cracking was observed in the sheet.

Example 2 A grain pattern was printed on synthetic paper weighing 30 g/m ² using a gravure printing machine. Note that a commonly used gravure ink was used as the printing ink, but a printing ink with the following formulation was used only for the dark-colored fiber portion of the texture pattern.

Alkyd type resin 40 parts Pigment 30 parts Solvent 50 parts DPT 40 parts Next, a transparent paint having the following composition was applied to the entire surface of the printing paper and dried at 200°C for 30 seconds to foam and harden the paint.

Saturated polyester resin 140 parts Unsaturated polyester resin 100 parts Isocyanate 45 parts Solvent appropriate amount Thereafter, the foamed convex portions of the coating film were ground with a No. 150 buff to produce a decorative sheet having concave portions that matched the dark-colored cloth pattern.

In addition, several sheets of melamine resin-impregnated paper (resin impregnation rate 55%) were layered on the back of the decorative sheet and heated at 120℃-10
Kg/cm ^{2 -} No cloudiness or uneven gloss was observed on the surface after hot-pressure bonding for 15 minutes.

〔Effect of the invention〕

In the manufacturing method of this invention, since the paint is a mixture of saturated polyester resin, unsaturated polyester resin, and isocyanate, and is dried at high temperatures, the chemicals in the ink rapidly decompose and generate gas, and at the same time the unsaturated The polyester resin and isocyanate react rapidly, trapping gas in the coating film to form a hard and brittle foamed coating, and also crosslink with the saturated polyester resin due to heat action, resulting in a strong coating in the non-foamed areas. It has flexibility.

On the other hand, the convex parts where the paint film foams and bulges are brittle because the unsaturated polyester resin and isocyanate rapidly react and harden, and the paint film can be easily removed by simply sanding the surface. It is possible to form a recessed portion.

Since the coating film in the production method of the present invention does not contain any acid, the decorative surface does not become uneven or cloudy even when heated and pressurized, and does not generate irritating odors such as formalin. Furthermore, the decorative material obtained by the production method of the present invention can fully exhibit the characteristics of polyester resin, and has the effect of providing a decorative sheet with excellent water resistance and heat resistance. There is.

Claims (1)

[Claims] 1. A printed pattern is applied to the surface of a sheet using an ink mixed with a chemical that generates decomposition gas when heated, and then a paint is applied on the printed pattern, which is a mixture of saturated polyester resin, unsaturated polyester resin, and isocyanate. is applied and heated at a temperature at which the chemical rapidly decomposes to decompose the chemical and dry and harden the paint, and the decomposition gas generated in this process raises the paint applied on the printed pattern and creates convex portions. 1. A method for producing a flexible decorative material having concave portions that match a printed pattern, the method comprising forming a convex portion and then grinding the convex portion to expose an ink surface.