JPH0367752B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a decorative sheet having recesses that match a printed pattern.

[Conventional technology]

Agents such as sulfides, carbonates, and dietrosopentamethylenetetramine (DPT) that react with the acidic catalyst in the overcoating paint to generate decomposed gas are mixed into the ink, and the ink is used to coat the substrate. After printing a pattern on the surface, paint is applied to the upper part, and the decomposed gas generated during this process is captured in the paint film.Then, the paint film layer on this foamed area is ground to create recesses that are perfectly aligned with the printed surface. A method for manufacturing a decorative board having such a structure is disclosed in Japanese Patent Publication No. 51-30099, Japanese Patent Publication No. 51-49246, etc.

[Problem that the invention seeks to solve]

By the way, in the decorative board manufactured by the above method, in the method of first creating a decorative sheet using a sheet-like material such as thin paper or synthetic resin film as a base material, and then pasting this onto a substrate such as plywood, the decorative sheet is The sheets tend to curl, have poor flexibility, and easily crack or tear, making it difficult to attach them to substrates in many cases.

The reason for this is that amino resin (melamine or urea resin) is applied to a thin sheet material weighing approximately 20 to 30 g/ ^m2 using amino alkyd resin paint, which is commonly used to improve the grindability of foamed coatings. This is because it is necessary to apply the paint with a high blending ratio to a thickness sufficient to capture the decomposed gas, and the resulting decorative sheet will be more brittle and breakable than a normal decorative sheet with a smooth surface. I didn't get it.

[Means for solving problems]

The reason why a paint made by mixing an alkyd resin and an acidic catalyst with an amino alkyd resin is used is that if the aluminum component in the amino alkyd resin is increased, the abrasiveness and hardness of the paint film will decrease. However, it has been found that when aluminum resin is added alone to aminoalkyd resin, although the flexibility of the coating film increases, the grindability hardly decreases.

Although the reason for this is not clear, it is probably because the added alkyd resin makes the foamed coating film brittle.

This invention was completed based on this knowledge, and after printing a pattern on the surface of a sheet using ink mixed with a chemical that reacts with the acidic catalyst of the acidic curing resin to generate decomposed gas. , apply a resin paint made by adding and mixing alkyd resin and acidic catalyst to amino alkyd resin, dry and harden at high temperature,
The decomposition gas generated during the drying and curing process raises the paint on the top of the printed pattern to form a convex part, and then the convex part on the top of the pattern is ground to expose the ink surface, and then the entire surface is coated with aminoalkyd. This is a method for producing a decorative sheet having concave portions that match the printed pattern, which is free from the above-mentioned problems and is smooth and does not crack even under slight impact, by overcoating with a resin paint and drying it.

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 30 g/m ² is preferably used. The reason for this is that it is not only inexpensive, but also has a smooth surface and excellent printability.

Next, two or three layers of ink are printed on the top surface of the sheet using a normal gravure printing device to form a pattern. DPT, which is a chemical that reacts with acidic curing catalysts to generate decomposed gases such as nitrogen gas and carbon dioxide, and sulfides such as calcium sulfide and iron sulfide, are added to the ink only in the areas where you want to express depressions.
Carbonates such as calcium carbonate, barium carbonate, and alkali bicarbonate are added.

i.e. DPT, calcium sulfide, iron sulfide,
Calcium carbonate, barium carbonate, alkali bicarbonate, etc., react with acidic substances or substances that generate acids, such as inorganic acids, organic acids, butyl phosphate, ammonium chloride, etc., which are acidic catalysts such as amino alkyd resins and acid-curing phenolic resins. , nitrogen gas, sulfide gas,
Carbon dioxide gas or the like is generated, and the generated gas is used to raise the paint film applied to the top surface of the ink.

The amount of the above-mentioned agent added to the ink is desirably in the range of 30 to 50 parts by weight per 100 parts by weight of the ink in order to sufficiently raise the coating film by the decomposition gas generated from the ink.

Next, a resin paint prepared by adding and mixing an alkyd resin and an acidic catalyst to an amino alkyd resin paint is applied to the entire surface of the above printed pattern. The amino alkyd resin paint used in this invention is a paint in which the mixing ratio of amino resin and alkyd resin is in the range of 1:4 to 3:2 and the resin solid content is 70% or more. Paints with a relatively high resin solid content of 70% or more are used for decorative paper with a smooth surface.
The amount of paint applied is about 5 to 8 g/ ^m2 , but in this invention, the gas is captured in the coating film, so the amount of paint applied is much larger than the conventional one, 10 to 20 g/ ^m2.
Therefore, the purpose is to simplify the coating process as much as possible, and to reduce the chance of penetration to the back side of the paper.

The alkyd resin added to the above paint has a molecular weight of 4000 to 5000, an acid value of 3 or less, and an OH
It is preferable to use one having a value of 120 to 150 and a solid content of about 80%. As an acidic catalyst,
It is a substance that generates inorganic acids such as hydrochloric acid and sulfuric acid, organic acids such as phosphoric acid and para-toluenesulfonic acid, and even acids such as ammonium chloride.

The amount of alkyd resin added is 5 to 50 parts by weight per 100 parts by weight of the above amino alkyd resin paint.
The amount of acidic catalyst in a 50% solution is about 20 to 30 parts by weight.

It should be noted that if the alkyd resin is added in an amount exceeding the above range, the grindability and hardness of the coating film will decrease, which is not preferable. If the acidic catalyst is added in a large amount, it will remain in the coating film and accelerate the deterioration of the coating film, so it is preferable to keep the amount added as small as possible.

The applied paint is then heated at a temperature that rapidly accelerates the decomposition reaction of the chemicals in the ink and the curing of the aminoalkyd resin (usually at a high temperature of 120°C or higher).
The paint is dried and cured using decomposition gas, and the paint on the top of the printed pattern is raised to form convex portions.

Grinding of the convex parts where the paint film has foamed and raised can be done by lightly polishing the surface of the sheet using a high-speed rotating buff roll with abrasive grains of about 150 grit on the polishing roll. is easily removed to form a recess.

Finally, the entire surface of the sheet is coated with a commonly used amino alkyd resin paint. The paint has a blending ratio of amino resin and alkyd resin of 1:1.
The resin solid content is about 45-50%, and the application amount is 3.
~5g/ ^m2 .

〔Example〕

Example 1 A wood grain pattern was printed on thin paper weighing 23 g/m ² using a gravure printing machine. As the printing ink, a commonly used ink for Clavia was used, but printing ink of the following formulation was used only for the thin tube portion with the wood grain pattern.

Cellulose resin: 50 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 140 for 20 seconds to foam and harden the paint. The amount of paint applied is 15g/
^m2 .

Melamine alkyd resin 100 parts Alkyd resin 15 parts Acidic catalyst (50% solution) 10 parts Solvent Appropriate amount Then, use a No. 150 buff to grind the foamed convex portions of the coating film to form a decorative sheet with concave portions that match the conduit thin film. Obtained. Then, the top surface of the decorative sheet was overcoated with 5 g/m ² of ordinary amino alkyd resin paint to create a flexible decorative sheet.

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

Alkyd resin 40 parts Pigment 30 parts Solvent 50 parts Sodium bicarbonate 40 parts Next, a transparent paint having the following composition was applied to the entire surface of the printing paper and dried at 130°C for 30 seconds to foam and harden the paint. The amount of paint applied is 13
g/ ^m2 .

Melamine alkyd resin 100 parts Alkyd resin 13 parts Acidic catalyst (50% solution) 20 parts Solvent Appropriate amount Then, use a cloth buff to grind the foamed convex portions of the coating film to form a decorative sheet with concave portions that match the pattern of a dark cloth grain. Manufactured. The top surface of the decorative sheet was then overcoated with a commonly used amino alkyd resin paint to obtain the desired decorative sheet. Note that the decorative sheet had flexibility, and almost no curls were observed.

〔Effect of the invention〕

In the method for producing a decorative material of the present invention, a paint mixture of an alkyd resin and an acidic catalyst is added to an amino alkyd resin, and although the flexibility of the paint film increases, the grindability hardly decreases. Therefore, when adhering decorative sheets,
The sheet does not curl or tear easily, can be attached to a substrate relatively easily, and has good shelf life.

Claims (1)

[Claims] 1. After printing a pattern on the surface of a sheet using an ink mixed with an agent that reacts with the acidic catalyst of the acidic curing resin to generate decomposed gas, the alkyd resin and the acidic catalyst were added to and mixed with the aminoalkyd resin. A resin paint is applied, dried and cured at high temperature, and the decomposition gas generated during the drying and curing process raises the paint on the top of the printed pattern to form a convex part, and then the convex part on the top of the pattern is ground. A method for producing a decorative material having concave portions that match a printed pattern, which comprises: exposing the ink surface, then overcoating the entire surface with an amino alkyd resin paint and drying it.