JPH0215367B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD This invention relates to a method for manufacturing decorative inorganic boards used as building materials and the like. BACKGROUND ART Inorganic substrates made from hydraulic inorganic binders such as cement and calcium silicate are usually made by making a slurry made of a mixture of hydraulic inorganic binders using a wet paper making machine, and then forming an original paper product on felt. The felt is manufactured by sucking and dewatering the lower part of the felt using a suitable suction device, then winding it around a making roll to adjust the thickness, and curing and curing the obtained plate-shaped paper product. However, the inorganic substrates manufactured in this way are only white or gray depending on the material, and it has been impossible to obtain various hues required for the place where they are used. In addition, the inorganic substrate is efflorescence.
However, the appearance of the product deteriorates due to the occurrence of dirt and contamination during use. In order to solve these problems, conventional methods include applying emulsion paint to a plate-shaped excipient and then curing and curing it, and applying various coating compositions to a dry inorganic substrate. However, the above-mentioned method has drawbacks such as insufficient adhesion of the coating film and excessive coating costs, and requires improvement. Therefore, a method has been proposed in which the water content of the original paper product is adjusted to a low level before it is rolled up on a making roll, and an emulsion paint is applied to it, and then the water is further dehydrated using a suction machine and the paper is then wound on a making roll. (Japanese Patent Application Laid-Open No. 58-26090). However, according to this method, after applying the water-based paint 1, as shown in FIG. Since there are many voids 6 in the raw paper article 2' which has a low water content, the water-based paint 1 on the surface cannot be sufficiently absorbed. Therefore, the water content of the layer consisting of the water-based paint 1 is high, and the paint does not penetrate into the interior of the original paper article 2', which has a low water content.
As a result, when removing the coated surface wrapped around the making roll, problems such as part of the coated film remaining attached to the making roll or adhesion such as peeling, cracking, and peeling of the coated surface remained. . Problems to be Solved by the Invention In view of the above-mentioned current situation, the present invention provides that when a part of the coating film of a paper product is rolled up with a making roll,
To stably obtain a decorative inorganic board that does not remain attached or stick to a making roll, has no peeling, peeling, or cracking of the coated surface, and has a good appearance. Means for Solving the Problems Therefore, the present inventors have devised a method for stably manufacturing decorative inorganic boards of excellent quality by improving the problems encountered when manufacturing the conventional decorative inorganic boards described above. As a result of continuing research for development, we adjusted the moisture content of the original paper product to a certain range higher than conventional values, applied a water-based paint to it, and then dehydrated it by suction using a suction machine. Next, this is wound around a making roll to adjust the thickness of the paper product, and when the wrapped paper product is removed, a part of the coating film applied to the surface layer of the paper product may remain attached or stick to the making roll. We have discovered that this is not the case, and have arrived at the present invention. That is, in order to solve the above-mentioned problems, the present invention involves making a slurry containing a hydraulic inorganic binder as a main component using a wet papermaking machine, and applying a water-based paint, preferably an emulsion, to the surface of the resulting raw papermaking body. In a method for manufacturing a decorative inorganic board, in which a paint is applied, then suction dehydrated, the thickness of the paper product is adjusted by winding it around a making roll, and the resulting plate-like paper product is cured and cured, the water content of the original paper product is 75~150
The present invention provides a method for producing a decorative inorganic board, which is characterized in that it is coated with a water-based paint. This invention will be explained in detail below. (Hydraulic inorganic binder) Examples of the hydraulic inorganic binder used in the present invention include cement, calcium silicate, blast furnace slag, calcium aluminate monosulfate hydrate, and a mixture of gypsum. It can be used as a species or as a mixture of two or more kinds. This hydraulic inorganic binder is mixed with asbestos, cellulose, and fibers of synthetic resins such as polyamide and acrylic resins as reinforcing materials to form a slurry, and this is made into a slurry using a wet paper making machine to produce a raw paper product. (Water-based paint) In this invention, the water-based paint includes emulsion paints, water-soluble resin paints, etc., and emulsion paints are particularly preferred. Emulsion paint is a conventional general paint, for example, a paint for interior and exterior use of buildings as specified in JIS-K-5663, and its constituent raw materials are resins such as acrylic and vinyl acetate. depending on,
It is a paint consisting of a suitable blend of cellulose-based protective colloid, coloring pigment, extender pigment, surfactant, and other additives. In the present invention, the original papermaking body refers to the papermaking process from the time when the slurry is made into paper using a wire cylinder in a wet papermaking machine and transferred onto felt until it is forcibly suctioned and dehydrated using a suction box or the like. Point to the body. In the present invention, it is important to adjust the moisture content of the original papermaking body in the above-mentioned section to 75 to 150%. In the present invention, the moisture content of the original papermaking body is a value calculated using the following formula. Moisture content = W ₁ W ₂ / W ₂ × 100 (%) W ₁ : Weight of paper product before drying W ₂ : Weight of paper product after drying (application of emulsion paint) Water content of original paper product made in this way rate 75
Adjust the water content to ~150%, preferably 80 to 120%, and apply the emulsion paint because if the water content of the paper product is less than 75%, the porosity will increase, and if it exceeds 150%, the water content will be high. Furthermore, since the paper cannot be sufficiently dewatered by suction after coating, the strength of the formed paper product is not sufficient, which is undesirable because it causes problems such as difficulty in peeling off from the making roll. There is no particular limit to the amount of water-based paint applied to the original paper structure in the present invention, but it is generally 50 to 200 g/m ²
A range of is appropriate. In the present invention, in order to apply water-based paint to the original paper product,
It is economical to apply the coating to the portion of the making roll that is to be wound up as the first layer, and is advantageous in terms of interlayer adhesion. Applying the continuous paper product only to the portion corresponding to the first layer of the making roll is achieved by employing a known automatic ON/OFF device. (Formation of decorative inorganic board) The raw paper article coated with the water-based paint according to the present invention is then dehydrated and dehydrated in exactly the same manner as the conventional method.
It is made into a product after the board thickness adjustment, curing and hardening process. That is, according to the present invention, the moisture content is 75~
The original paper product coated with water-based paint in a 150% state is dehydrated by suction from under the felt using a suction according to a conventional method, and then wound around a making roll to adjust the thickness of the paper product. The material is wrapped around a making roll until it reaches a certain thickness, then removed to form a plate-like paper product. If necessary, it is pressed to shape it, corrugated, and embossed, and then cured. A decorative inorganic board is produced by curing and, if necessary, drying. Function In the manufacturing method of the present invention, as shown in FIG. 1, water is removed by suction from the lower part of the felt 3 on the back side of the original papermaking body 2, which has a high moisture content, by a suction device 4 after application of the water-based paint 1. Sometimes, the voids 6 in the original papermaking body 2 with a high moisture content are smaller than those in the papermaking body with a low moisture content shown in FIG. At the same time, the paint layer made of the water-based paint 1 is also sucked in the direction shown by the arrow 8. The degree of this attraction is
Since the water-based paint 1 is stronger than those with a low water content, it is presumed that the water-based paint 1 penetrates into the interior of the original papermaking body 2, which has a high water content, and the water content of the paint layer decreases, forming a film. EXAMPLES The present invention will be described in more detail below with reference to examples of the present invention together with comparative examples, but it goes without saying that the present invention is not limited to these examples. Example 1 A slurry having the following composition was prepared.

[Table] The slurry with the above composition was made using a paper making machine, and the water content of the original paper product (dimensions: 35 cm wide x 0.5 mm thick, endless) was suctioned and dehydrated from under the felt. It was set at 80%. Note that the water content was calculated using the following formula. Moisture content = W ₁ - _{W 2} / W ₂ W ₁ : Weight of paper product before drying W ₂ : Weight of paper product after drying Apply an acrylic emulsion paint with the following composition on the surface of the raw paper product adjusted to the above moisture content. Papermaking body area 1
A coating weight of 100 g/m ² was applied.

[Table] After applying the above acrylic water-based paint 1 using an airless sprayer, water is removed by suction from below the felt using a suction (suction pressure: 35 cmHg), and a plate-shaped paper product with a thickness of 6 mm is made using a making roll. It was formed and cured for 3 weeks. The appearance, adhesion of the coating film, and releasability from the making roll of the decorative inorganic board produced in this manner were evaluated, and the results are shown in Table 1 below. Example 2 In the method of Example 1, the moisture content of the original papermaking body was
A decorative inorganic board was produced in the same manner as in Example 1, except that emulsion paint 2 was applied to the original paper structure after adjusting to 90%. The results are shown in Table 1. Example 3 In the method of Example 1, the moisture content of the original papermaking body was
A decorative inorganic board was produced in the same manner as in Example 1, except that emulsion paint 3 was applied to the original paper structure after adjusting the emulsion to 110%. The results are shown in Table 1. Comparative Example 1 In the method of Example 1, the moisture content of the original papermaking body was
A decorative inorganic board was produced in the same manner as in Example 1, except that the emulsion paint was applied after adjusting to 60%. Comparative Example 2 Comparative Example 2 was an unpainted curing substrate with the inorganic composition shown in Example 1. The results are shown in Table 1.

[Table] Effects of the Invention According to the present invention, when the papermaking body is removed from the making roll, a part of the coating film of the papermaking body does not remain attached or stick to the making roll, and the coated surface does not turn over or stick to the making roll. A decorative inorganic board with good appearance and no peeling or cracking can be stably obtained. In addition, since the water-based paint penetrates deeper into the papermaking body than those with low water content, the surface layer of the decorative inorganic board and the water-based paint layer are strongly bonded, resulting in excellent adhesion of the paint film, making it waterproof and resistant. A decorative inorganic board with excellent efflorescence properties can be obtained. Further, according to the present invention, it is possible to decorate the surface with paint in any color, and it is possible to prevent contamination during use.

[Brief explanation of drawings]

FIG. 1 is a conceptual cross-sectional view showing the operation of the method for manufacturing a decorative inorganic board according to the present invention, and FIG. 2 is a conceptual cross-sectional view showing the problems of conventional low moisture content paper products. 1...Water-based paint, 2...Original paper product with high water content, 2'...Original paper product with low water content, 3...Felt, 4...Suction device, 5...Water in the original paper product, 6...Void, 7...Movement of water in the original paper structure, 8...Movement of the water-based paint layer.

Claims (1)

[Scope of Claims] 1. A slurry containing a hydraulic inorganic binder as the main component is made using a wet paper making machine, a water-based paint is applied to the surface of the original paper made on felt, then water is removed by suction, and the slurry is wound around a making roll. In the method for producing a decorative inorganic board, the thickness of the original paper is adjusted by adjusting the board thickness, and the resulting plate-shaped paper is cured and hardened.
A method for manufacturing a decorative inorganic board, characterized by coating with a water-based paint at ~150%. 2. The method for producing a decorative inorganic board according to claim 1, wherein the water-based paint is an emulsion paint.