JPH01164478A - Production of inorganic decorative sheet - Google Patents

Abstract

PURPOSE:To prevent cracking by successively forming an underlayer from which a weak alkali component can be leached, a film of inorg. paint contg. a specified metal alkoxide as a binder as an intermediate layer and a film of such inorg. paint as a surface layer on an inorg. base material. CONSTITUTION:A synthetic resin film having many micropores is formed on an inorg. base material as an underlayer from which a weak alkali component can be leached. The underlayer is coated with an inorg. paint contg. a metal alkoxide represented by a formula M(OR)n (where M is Si, Ti, Al, Zr, Sr, Ba, Pb, Sn, La, Na or Fe, R is 1-10C alkyl and n is an integer of 1-4) as a binder and the paint is cured to form a paint film as an intermediate layer. The inter mediate layer is coated with inorg. paint contg. a metal alkoxide represented by said formula as a binder and the paint is cured to form a paint film as a surface layer. Thus, an inorg. decorative sheet is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention Field of the Invention The present invention relates to a method for manufacturing an inorganic decorative board that has excellent resistance to aging and can maintain good aesthetic appearance for a long period of time.

Prior art and its problems Conventionally, as a manufacturing method for inorganic decorative boards, for example, calcium silicate board, slag stone-il temporary, pulp cement Han 1 asbestos slate board, etc. There is a method of applying paint to form an organic coating film.

However, in this method, the paint film was prone to discoloration and cracks due to self-poring due to ultraviolet rays and rainwater, and due to alkaline components leached from the inorganic Jk material.

For this reason, it has been proposed to form an inorganic coating film by applying an inorganic paint with excellent weather resistance to the surface of the inorganic base material. For example, there is a method using an inorganic paint made of water-soluble sodium silicate salt, etc., as described in JP-A-50-54620.

However, in this method, the curing of the inorganic paint is only a reaction hardening of the inorganic paint itself, and in order to cure it, it is necessary to heat it at a high temperature of 200°C or more, so it is not easy to cure the inorganic paint and the undercoat paint. In addition, there were problems in that the inorganic base material was deformed by heat and the inorganic coating film was prone to cracking and peeling.

λ匪Δ倖Collection In view of the above-mentioned problems, the present inventors have discovered an intermediate coating and a surface coating that exhibit good coating film performance in conjunction with the inorganic base material and the undercoat, and have achieved good coating film performance. This led to the completion of a method for manufacturing inorganic decorative laminates.

That is, the gist of the present invention is to form a synthetic resin liquid coating film with a large number of micropores on the surface of an inorganic base material to obtain an undercoat film from which alkaline components of the inorganic base material can be leached out, After applying an inorganic paint containing a metal alkoxide as a binder represented by the general formula: % formula %) to the surface of the undercoat film and curing it to form an intermediate paint film, 1)
A method for producing an inorganic decorative board, characterized in that an inorganic paint containing a metal alkoxide represented by the above general formula as a binder is applied to the surface of the middle layer and cured to form a surface coating film.

Examples of the inorganic base material include calcium silicate pseudomonasbestos cement calcium silicate board 9 asbestos slate slab gypsum board, pulp cement board, and ALC.

Examples of the synthetic resin liquid include Evoquin resin, urethane resin, acrylic resin, and unsaturated polyurethane resin.

Examples of methods for applying the synthetic resin liquid include spraying, roll coater, and reverse coater. It is more preferable to apply one coat than to apply multiple coats.

The undercoat film obtained by curing the synthetic resin liquid was applied to a thickness of 5 mm to form microscopic pinholes and fine racks.
The thickness should be 20 μm or more and less than 20,071 m, preferably 20 μm or more and J28,011 ttt or less, and the surface to be coated should be weakly alkaline with P1 and 11 or less.

The reason why the undercoat film with a thickness of less than 200 μm and :4 is provided is that if there is no undercoat film, the surface to be coated will be strongly alkaline (
P t-1l 4 crop yield), and the metal alkoxide inorganic paint used as an intermediate coating, which will be described later, undergoes hydrolysis but is difficult to undergo a polycondensation reaction, resulting in poor curing.On the other hand,
This is because if the thickness of the undercoat film is 200 μI or more, it completely covers the inorganic base material and prevents the weak alkaline component from seeping out.

In addition, in the above-mentioned application method, the case where pinholes etc. are formed at the time of coating film formation has been explained, but it is not limited to this. Pinholes etc. may be formed in the coating film.

Alternatively, the moisture content of the inorganic group may be set to 1 to 10%, and pinholes or the like may be formed with water vapor generated when the synthetic resin liquid is heated and cured.

An inorganic paint (hereinafter referred to as
(referred to as "metal alkoxide-based inorganic paint"), specifically, 1t is silicon, titanium, aluminum, strontium, barium, lead, tin, lanthanum, zirconium, or iron, and 1t is methane, ether, propyl, or butyl. In the alkyl group such as pendel, n is an integer of 1 to 4.

Note that the metal alkoxide-based inorganic paint is titanium oxide. It is an n-color paint colored by appropriately mixing pigments such as iron oxide, sea, red lead, and chromium oxide.

When a catalyst such as ammonia is added to Moeki metal alcokind inorganic paint, the temperature ranges from room temperature to 180°C, preferably 70°C.
Hydrolysis occurs at 111λ degrees of heating at 150°C to 150°C,
It is cured by the polycondensation reaction shown below.

M(OR)n+n1(yO→M(OH)n+nR(OI
-1) M(OH)n-4Mo n/l + n/lHt
.

Moreover, the metal alkoxide-based inorganic paint is applied to the surface of the undercoat film, which is formed so that the weak alkaline component of the inorganic base material can be leached out.

Therefore, the weak alkaline component leached from the surface of the undercoat film acts as a catalyst and accelerates the curing reaction of the metal alkoxide-based inorganic paint. As a result, the metal alkoxide-based inorganic paint is uniformly cured, and cracks and peeling are less likely to occur.

Furthermore, after the curing reaction of the intermediate coating film made of the metal alkoxide-based inorganic paint, a very small amount of M-0 [■] and a weak alkaline component Ca (or
]), etc., form an ether bond, so the strength of the coating film is further improved.

The surface layer coating protects the middle layer coating, prevents the alkaline components of the inorganic base material from leaching to the surface of the coating, and prevents the surface of the inorganic decorative board from efflorescence.
It is made of a transparent metal alkoxide-based inorganic paint with the same composition as the metal alkoxide-based inorganic paint that forms the base.

The inorganic paint forming the surface layer coating film may be a colored paint and may be used in appropriate combination with the inorganic paint forming the middle layer coating film. The coating film may be formed from a transparent paint.

On the other hand, the coating method is the same as that for forming the middle layer coating film described above, so the explanation will be omitted.

Example! An asbestos cement calcium silicate plate with a specific gravity of 1.9 and a water content of 3% is coated with an epoxy resin paint of approximately 40% solidity, and then cured by heating at a temperature of 150°C for 6 minutes, resulting in a thickness of approximately 20%.
A Bm undercoat film was formed. This undercoat film had pinholes that were visible and microscopic, and when water was applied, it showed weak alkalinity with Pl (8).

Next, an inorganic paint containing a mixture of a white metal alkoxide-based main liquid and an ammonia-based auxiliary liquid is applied to the surface of the undercoat film, and cured by heating at a temperature of 150°C for 10 minutes to a thickness of about 20 μm. A middle layer coating film was obtained.

A transparent metal alkoxide-based inorganic paint was applied on the middle layer coating and cured by heating at a temperature of 150° C. for 10 minutes to obtain a sample having a surface layer coating with a thickness of approximately 20 μm.

Comparative example! The moisture content of the inorganic base material in Example 1 was set to 0%, and the epoxy resin paint was applied three times to a thickness of approximately 200%.
After forming the μ-th undercoat film, the other operations were the same as in Example 1 to obtain a sample.

Note that no pinholes were visually observed in the undercoat film, and no leaching of alkaline components was observed.

The sample obtained as described above was subjected to a 30-day immersion test in water, or a weather meter (W, O, M) was used.
Various measurements were performed on each sample that was subjected to a weather resistance test by exposure treatment for 1000 hours. The measurement results are shown in Table 1.

Table 1 *The appearance does not represent the results of visual observation of the external surface.

*Bone quality shows the results of a base grain test with a width of 1x11.

*Pencil hardness indicates the test results conducted according to JISDO202.

As is clear from Table 1, when the measurement results of Example 1 and Comparative Example 1 were compared before the test, it was found that both had equivalent performance before the test.

On the other hand, immersion test or weather meter (W, O).

M) Comparing the measurement results for each sample tested, it was found that in Comparative Example 1, the pencil hardness decreased for the sample subjected to the immersion test, and W
It was found that the appearance and adhesion of the samples treated with , O, and M deteriorated.

On the other hand, in the case of Example 1, the immersion test and W, O,
Regarding the samples subjected to the M test, no deterioration in coating performance was observed, and in fact, it was confirmed that the adhesion was improved, and it was confirmed that a decorative board with excellent durability could be obtained.

After the metal alkoxide paint is applied and cured, the alkaline components present in minute amounts in the paint film and Ca(OH) etc. leached from the inorganic base material form ether bonds, resulting in gradual paint loss. This is thought to be due to improved film performance.As is clear from the above explanation, according to the present invention, a large number of micropores are formed in the undercoat film on the surface of the inorganic base material to improve the performance of the inorganic base material. This allows weak alkaline components to be leached out. Therefore, when the metal alkoxide-based inorganic paint applied to the surface of the undercoat film undergoes a curing reaction, the weakly alkaline component acts as a catalyst and accelerates the curing reaction.
In addition to uniformly curing metal alkoxide-based inorganic paints, the paint film is hard to crack or peel because it is reinforced by the bond between the reactive groups remaining after the paint film is formed and the weak alkaline component.

In addition, since the metal alkoxide-based inorganic paint is overcoated on the surface of the middle layer coating, it is possible to prevent the weak alkaline components of the inorganic base material from leaching to the surface of the surface coating. It can be prevented.

This has the effect of preventing discoloration and uneven gloss on the surface of the inorganic decorative board.

Claims (3)

[Claims] (1) Form a synthetic resin coating film with a large number of micropores on the surface of an inorganic base material to obtain an undercoat film from which weak alkaline components of the inorganic base material can be leached, and then apply the coating film to the surface of the undercoat film. , General formula: M(OR)_n [wherein M is silicon, titanium, aluminum, zirconium, strontium, barium, lead, tin, lanthanum, sodium or iron, R is an alkyl group having 1 to 10 carbon atoms, and n is an alkyl group having 1 to 10 carbon atoms. Indicates an integer from 1 to 4. ] After applying and curing an inorganic paint containing a metal alkoxide represented by the above formula as a binder to form an intermediate coating film, an inorganic paint having a metal alkoxide represented by the above general formula as a binder is applied and cured on the surface of the intermediate layer. A method for producing an inorganic decorative board, characterized by forming a surface coating film. (2) The method for manufacturing an inorganic decorative board according to claim 1, wherein the inorganic paint forming the surface coating film is a transparent paint. (3) The method for manufacturing an inorganic decorative board according to claim 1 or 2, wherein the inorganic paint forming the intermediate coating film is a colored paint.