JPH04164879A - How to color cement products - Google Patents

Abstract

PURPOSE:To obtain a colored cement product, capable of stacking thereof just after coating and excellent in also water resistance and durability after hardening by feeding a powdery material containing a powder coating, composed of a thermoplastic resin and added to cement onto the surface of a cement product and curing the resultant product under specific conditions. CONSTITUTION:A powdery material containing 3-100 pts. powder coating, composed of a thermoplastic resin and added to 100 pts. cement is fed onto the surface of a cement product and water required to carry out hydrating reaction of cement is added. The resultant coated product is then cured in an autoclave under temperature conditions above the melting point of the powder coating to color the cement product. The reason why the powder coating is added in an amount of 3-100 pts. is as follows. If the amount thereof is smaller than 3 pts., required water resistance cannot be imparted to films and sufficient coloring cannot be performed. If the amount is larger than 100 pts., the amount of the blended cement is reduced in inverse proportion thereto and the film strength is deteriorated.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a method for coloring cement products.

[Conventional technology]

BACKGROUND ART Conventionally, building materials such as blocks, wall plates, roofing materials, etc. are made of cement products such as fiber-reinforced cement.

By the way, the above-mentioned cement products are water-absorbent as they are, and the surface of the base material is an achromatic color ranging from grayish-white to grayish-black and lacks design properties. Therefore, in order to provide water-absorption resistance and aesthetic appeal, the surface is made to have water resistance. It is common to paint them in various colors using paints.

This coating method involves supplying a liquid or powder coating material, which is a mixture of cement and color pigments, to the surface of the cement product, and in the case of powder raw materials, after supplying the moisture necessary for the hydration reaction, the coating material is cured in an autoclave. A method of curing is known, or a method of adding a coloring pigment to cement and adding an emulsion resin to form a liquid coating is supplied to the surface of a cement product, and the method of curing by natural curing is known.

C. Problems with conventional technology] However, the former coating method hardens the coating layer through the hydration reaction of cement, so it has problems with water resistance or durability, and in this respect, the latter coating method can be said to be superior. .

However, since the latter emulsion resin is used as a liquid raw material, it is not possible to stack the products until the coating film is cured after painting, which makes handling difficult.

[Problem to be solved by the invention]

This invention was made in view of the above-mentioned problems, with the purpose of providing a method for coloring cement products that allows products to be stacked after being coated and that also has excellent strength such as water resistance and durability after hardening. It is something.

[Technology that led to solving the problem]

That is, in the method for coloring cement products of the present invention, 3 to 1 part of powder coating made of thermoplastic resin is added to 100 parts of cement.
00 parts of the powder material is supplied to the surface of the cement product, water necessary for the hydration reaction of the cement is added, and the material is autoclaved at a temperature higher than the melting point of the powder coating made of the thermoplastic resin [4]. It is characterized by:

[Effect]

The cement product to which this invention is applied may be any product molded with cement as a main component, such as roofing materials, wall panels, professional boards, etc.

In this invention, as a material for coloring the cement product, a material prepared by adding 3 to 100 parts of a powder coating made of a thermoplastic resin to 100 parts of cement is used.

The reason for adding 3 to 100 parts of powder coating made of thermoplastic resin to 200 parts of cement cement is that if it is less than 3 parts, it will not be possible to impart the necessary water resistance to the coating film and sufficient coloring will not be achieved. This is because if the amount exceeds 100 parts, the cement content decreases in inverse proportion to this, resulting in a decrease in coating film strength.

The above powder material can be made into a liquid state by adding water, or it can be supplied in a layered form to the product surface as a powder without adding water, and if it is in powder form, it can be made into a thermoplastic material after replenishing the water necessary for the hydration reaction. It is cured in an autoclave at a temperature above the melting point of the resin powder coating.

At this time, the cement component undergoes a hydration reaction during autoclaving and hardens, and at the same time, the powder coating is also melted by the heat, and they are mixed together to form a single coating film.

Therefore, the cured coating film develops strength due to the cement hydration reaction, and at the same time, sufficient water resistance is imparted by the thermoplastic resin cured by cooling.

Note that reinforcing fibers such as pulp and asbestos can also be added to the cement.

〔Example〕

Next, this invention will be explained in detail.

Powder material having the composition shown in Table 1 was mixed uniformly using a high-shear mixer, and the obtained powder material was spread on the surface of the cement board using a spreader at a rate of 500 g/n, followed by water. Pressure was applied using a press.

Table 1 In Table 1, the comparative example uses an iron oxide red pigment as a coloring raw material.

The colored painted board obtained above was naturally cured for 2 hours, and then
Autoclave curing was carried out under the conditions of kg/cd x 180°C for XIO hours.

The results of the coating film test after the coating film was cured were as shown in Table 2.

In Table 2, *1 acid resistance test is a test in which the product is immersed in a 1% hydrochloric acid solution for 24 hours to check for surface abnormalities, and *2 weather resistance test is a test conducted for 2000 hours using a sunshine weather meter.

As is clear from Table 2, the product according to the present invention achieved good results in all test items.

A *3 defect in the Comparative Example indicates that efflorescence occurred significantly during autoclave curing, and re-coating was required to achieve a beautiful surface.

〔effect〕

As explained above, according to the present invention, the paint film is made of thermoplastic resin powder that is once melted with hardened cement and hardened while blending with the cement matrix and the clay. This makes it possible to create a coating film that is excellent in both strength and water resistance.

Claims (1)

[Claims] (1) A powder material made by adding 3 to 100 parts of a powder coating made of thermoplastic resin to 100 parts of cement is supplied to the surface of the cement product, water necessary for the hydration reaction of the cement is added, and A method for coloring a cement product, which comprises curing in an autoclave at a temperature higher than the melting point of the powder coating made of the thermoplastic resin.