JPS60155585A - Manufacture of construction board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method of manufacturing a molded and cured architectural board containing cement as a main component.

(Background technology) Conventionally, in manufacturing this type of architectural board, a slurry in which cement and fiber parts are dispersed in water is made into a paper sheet to create a paper sheet, and then the paper sheet is pressed with a mold. The raw board is manufactured by curing it, but if left as is, it has the disadvantages of poor water permeability, easy formation of effluents on the surface, and poor adhesion with top coat paint. Therefore, a synthetic resin liquid is applied to the surface of the molded raw board to treat the surface. However, when the synthetic resin liquid is applied to the surface of the raw board after press forming, it is difficult to apply the synthetic resin liquid evenly due to the uneven pattern formed by the mold on the surface of the raw board, and the liquid does not flow into the raw board. The disadvantages were that the adhesion between the green board and the synthetic resin was poor without impregnation, and the adhesion with the painted film was insufficient.0 (Object of the Invention) The present invention was made in view of the above points. For architectural use, it has good water permeability, is difficult to generate ef-resence, and can evenly apply synthetic resin liquid to the surface, and can improve adhesion to the paint film. The object of the present invention is to provide a method for manufacturing a board.

(Disclosure of the Invention) That is, the method for manufacturing a construction board of the present invention comprises a slurry (
A synthetic resin liquid (3) is applied to the surface of the paper sheet (2) formed by paper-making 1), and white water is sucked from the back side of the paper sheet (2), and then this paper sheet (2) is molded. When pressing and curing the obtained raw board (4) to produce a board for construction, the melt flow temperature of the synthetic resin is set higher than the molding temperature of the mold and lower than the curing temperature. This is characterized by applying synthetic #ll liquid 3) and impregnating it into the paper sheet (2) before pressing the raw board (4), so that the uneven pattern on the surface due to molding can be improved. The synthetic resin liquid (3) can be applied uniformly regardless of the melt flow temperature (M
By setting FT> at the above-mentioned temperature, the resin film is melted and hardened during curing to form a resin film, thereby achieving the above object.

The present invention will be explained in detail below. As shown in Figures 1 and 2, a slurry (ll) in which cement, fiber materials, crushed hardened materials, etc. are dispersed in water is transferred from a drum (6) to an endless belt (5) made of felt, wire mesh, etc. supply to the top surface of
While being fed by an endless belt (5), white water is placed on the back side of the endless belt (6) and white water is sucked by the comb section (7) to create a paper sheet (2). At that time, a synthetic resin liquid (3) such as acrylic emulsion or acrylic styrene emulsion is applied to the upper surface of the paper-made sheet (2), and the synthetic resin liquid (3) is applied to the paper-made sheet (3) by suction from each of the nine cushion boxes (8). 2) is impregnated into the inside. Then,
The paper sheet 2) is pressed with a mold to form an embossed pattern on the surface, and a patterned raw board (4) is formed in this way.
As shown in Fig. 3, a plurality of boards are laminated and cured at a set temperature to obtain a construction board. Here, the melt flow temperature (M
FT) is set higher than the molding temperature of the mold and lower than the curing temperature, so that the synthetic resin does not melt and adhere to the mold during pressing with the mold, while the raw board (4) During curing, the synthetic resin melts and a hardened synthetic resin film is formed on the surface.

Therefore, the synthetic resin liquid (3) is deposited on the surface of the paper-made sheet (2).
By applying this and sucking white water from the back side of the paper sheet (2), the synthetic resin liquid (3) is impregnated into the inside of the paper sheet (2), and then the synthetic resin is melted and hardened by the curing temperature. By doing so, a hardened synthetic resin film is formed on the surface of the building board, and this film is firmly bonded to the internal layer of the building board, improving the surface strength of the building board. At the same time, it is possible to improve the adhesion with the coating film that is subsequently applied to the surface. Furthermore, a hardened synthetic resin film is formed over the entire surface, which improves the water permeability of the surface and prevents the occurrence of efflorescence. Furthermore, as mentioned above, since the synthetic resin melts on the surface of the green board (4) during curing, it is also possible to prevent moisture from escaping during curing. Furthermore, even if the base material is alkaline, there will be no problem as long as an alkaline synthetic resin liquid is selected.

The present invention will be specifically explained below based on Examples (Examples 1 to 5 and Comparative Example 1.2) 100 parts by weight of Portland cement (hereinafter simply referred to as parts), 7 parts of Pal'j, 1 part of alkali-resistant glass fiber A slurry with a slurry concentration of 7 to 8% was prepared by dispersing 1 part of vinylon fiber, 1 part of a crushed hardened product in water, and this slurry was made into a paper sheet using a Fourdrinier paper machine. Each synthetic resin emulsion shown in Table 1 below was applied onto the paper sheet by spraying in the form of a sheet, and the water was dehydrated in a suction box with a suction pressure of 10 to 20 cmHf to impregnate the paper sheet with the synthetic resin emulsion.Next, the paper sheet was impregnated with the synthetic resin emulsion. The sheet is molded at a mold temperature of 35 to 40°C and a press surface pressure of 1
A pattern is applied by pressing with a 0-20kg 1tri mold, and then 100 sheets of the obtained green board (thickness 12mm) are loaded and steam-cured for one week at a temperature of 50-60'C. A construction board having a specific gravity of 1.20 and a moisture content of 10% after drying was obtained.

<Conventional Example 1> A construction board was obtained in the same manner as in the example except that the synthetic resin emulsion was not applied to the paper sheet.

<Conventional Example 2> A building board was obtained in the same manner as in the example except that the synthetic resin emulsion was press-molded using a mold and then applied onto the green board.

Next, we will examine the results of measuring the depth of the synthetic resin emulsion during the production of the above architectural boards, the adhesion of the synthetic resin to the mold, and the planar adhesive strength and coating adhesion of the architectural boards. show. In addition, -second adhesion indicates the peel strength before curing,
The hot water test shows the peel strength after immersion in hot water.

From the results shown in Table 1 above, it was confirmed that the strength and film adhesion of the example in which the synthetic resin emulsion was applied and impregnated onto the paper sheet before pressing was improved, especially when compared with the example. In comparison with the example, MFT of synthetic resin was determined at mold temperature (35~
40-5 from curing temperature (50-60℃)
It was confirmed that by setting the temperature to 0°C, it was possible to prevent the synthetic resin from adhering to the mold during mold pressing, and that the adhesion of the coating film in the hot water test was improved.

(Effects of the Invention) As described above, in the present invention, the synthetic resin liquid is applied to the surface of the paper sheet so that water is absorbed from the back side of the paper sheet, so the synthetic resin liquid can be well impregnated into the paper sheet. Then, by melting and curing this synthetic resin, a hardened synthetic resin film with good adhesion to the base material can be formed on the surface, improving the water permeability of the surface and preventing water from entering during curing. In addition to being able to prevent the escape of efflorescence and the occurrence of efflorescence, it is also possible to improve the surface strength of architectural boards and the adhesion with the coating film. Furthermore, since the synthetic resin liquid is applied and then pressed using a mold, the synthetic resin liquid can be uniformly applied to the surface regardless of the uneven pattern formed by the mold.

Furthermore, since the melting temperature of the synthetic resin is set higher than the molding temperature of the mold, there is no problem of the synthetic resin adhering to the mold during pressing.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of an embodiment of the present invention, FIG. 2 is a schematic explanatory diagram of the main parts of the same, and FIG. 3 is a perspective view of the same. +11 is slurry, (2) is paper-made sheet, (3) is synthetic resin liquid, +4) r/'i green board. Agent Patent Attorney Ishi 1) Choshichi

Claims (1)

[Claims] [1] Apply a synthetic resin liquid to the surface of the paper sheet formed by paper-making the slurry, apply the cloth, and suck white water from the back side of the paper sheet, then press this paper sheet with a mold, and press the resulting raw material. A method for producing a construction board, which comprises setting the melt flow temperature of a synthetic resin higher than the molding temperature of a mold and lower than the curing temperature when the board is cured to produce a construction board.