JPH0948681A - Hardened material of gypsum and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hardened material of gypsum by specifically coating the surface of a hardened material of gypsum, hardly being damaged during handling, excellent in application, preventing change in color by molds, etc. SOLUTION: The surface of a hardened material of gypsum is abraded and the abraded powder on the surface is removed. Then the surface of the hardened material of gypsum is coated with an acrylic emulsion, a vinyl acetate emulsion or a polyvinyl alcohol coating material to give the objective hardened material of gypsum. The hardened material of gypsum is a hardened material of gypsum obtained by coating the surface of a hardened material of gypsum with the acrylic emulsion, the vinyl acetate emulsion or the polyvinyl alcohol coating material. The acrylic emulsion, the vinyl acetate emulsion or the polyvinyl alcohol coating material as an undercoating material is applied preferably in the ratio of 150-200g based on the unit area (1m<2> ) of the surface of the hardened material of gypsum. A coating material is preferably applied generally in the ratio of 100-150g based on the unit area (1m<2> ) of the surface of the hardened material of gypsum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gypsum hardened product and a method for producing the same, and in particular, because of its high surface hardness, it is less likely to be scratched during handling, and has excellent workability on site.
The present invention relates to a gypsum hardened body capable of preventing the generation of mold and a method for producing the same.

[0002]

2. Description of the Related Art Gypsum hardened products, especially as shown in FIG.
A light-weight gypsum hardened product in which a lightweight intermediate layer 2 containing air bubbles is interposed between a pair of dense outer layers 1 and 3 is excellent in heat insulation, sound insulation, and fire resistance, and is lightweight and easy to handle and work. Since it is excellent, it is widely used as various building materials.

As shown in FIG. 2, the light-weight gypsum hardened body of this three-layer structure supplies a gypsum kneaded material for forming an outer layer onto the belt conveyor 4 to form a first layer 11, and the first layer 11 is formed. A gypsum kneaded material containing bubbles is supplied to form a second layer 12, and a gypsum kneaded material for forming an outer layer is further supplied to form a third layer 13 to cure the gypsum during transportation. Then, it is cut into a predetermined size and dried by a drier.

The gypsum kneaded product for forming the outer layer is a dense gypsum hardened product obtained by kneading calcined gypsum, glass fiber and water with a mixer 5.

Further, the gypsum kneaded product for forming the intermediate layer is a product in which bubbles are supplied to the kneaded product to contain air bubbles.
The foam is a light-weight gypsum hardened product obtained by stirring a mixed liquid of polyvinyl alcohol (PVA), water and a surfactant together with air in the foaming machine 6 to foam.

Reference numeral 5a in FIG. 2 shows a chute for supplying the gypsum kneaded material. Reference numerals 7, 8 and 9 denote plates (forming spatula) for pressing the kneaded material to adjust it to a predetermined thickness.

The hardened gypsum hardened product after hardening is finely adjusted to have a predetermined size as needed, and therefore at least one of the outer layers (hereinafter referred to as the surface) is polished by a polishing machine.
After polishing, it will be shipped as a product.

In the construction of this light-weight gypsum hardened product, after undercoating the light-weight gypsum hardened product on the site,
Although the main coating is applied or a decorative paper is attached, the surface of the hardened gypsum has abrasive powder of gypsum generated during surface polishing. Therefore, prior to undercoating, after removing the polishing powder, the undercoating is performed.

[0009]

In the conventional gypsum hardened product, it is necessary to remove the polishing powder on the surface and to perform the undercoating for the construction on site, which requires a lot of man-hours and is troublesome for the construction. In particular, the removal work of the polishing powder is troublesome and the dust treatment at the time of removal becomes a problem, and since it is necessary to wait for the drying time after performing the undercoat coating, this causes a longer construction period. Was becoming.

In addition, since the surface of the cured gypsum is soft as it is and easily scratched, the surface may be scratched during transportation or handling during construction, resulting in inferior product value. However, there was also a problem that it required careful handling. In addition, when used as an interior material on the exterior wall of a building, a phenomenon that occurs mainly in the winter when the temperature difference between the inside and outside is large is the phenomenon of dew condensation on the wall surface, which causes mold and the like. Or, during the hot and humid seasons such as the rainy season, mold develops especially in places where ventilation is poor, and the wall surface is discolored.

The present invention solves the above-mentioned conventional problems and has high surface hardness so that it is not easily scratched during handling, is excellent in workability on site, and discolors due to mold on the surface of the cured product. An object of the present invention is to provide a gypsum hardened body that prevents the occurrence of the above and a method for producing the same.

[0012]

The gypsum hardened product according to claim 1 is characterized in that the surface of the gypsum hardened product is coated with an acrylic emulsion, a vinyl acetate emulsion or a polyvinyl alcohol paint.

According to a second aspect of the present invention, in the method for producing a cured gypsum, after polishing the surface of the cured gypsum, the polishing powder on the surface is removed, and then the surface of the cured gypsum is acrylic emulsion, vinyl acetate emulsion or polyvinyl alcohol. It is characterized by applying paint.

According to a third aspect of the present invention, there is provided a method for producing a hardened gypsum kneaded product, a step of supplying the kneaded gypsum kneaded product onto a conveyor, molding the gypsum kneaded product on the conveyor, and drying the hardened gypsum kneaded product. In the method for producing a gypsum hardened product comprising a drying step, after the drying step, a surface treatment step comprising a polishing machine, a polishing powder removing means and a paint sprayer is provided, and after the surface of the dried gypsum hardened material is polished. It is characterized in that the polishing powder on the surface is removed, and then an acrylic emulsion, a vinyl acetate emulsion or a polyvinyl alcohol-based paint is applied to the surface of the cured gypsum by a paint sprayer.

According to a fourth aspect of the present invention, a gypsum hardened product and a method for producing the same are prepared by applying an antifungal agent to these paints when applying an acrylic emulsion, a vinyl acetate emulsion or a polyvinyl alcohol-based paint to the surface of the gypsum hardened product. When the applied gypsum hardened product and the surface of the gypsum hardened product are polished, and the polishing powder on the surface of the gypsum hardened product is removed, when the paint is applied to the surface of the gypsum hardened product, the antifungal agent is mixed into the paint. Is a method for producing a cured gypsum, which is applied, in the production process line of the cured gypsum, a polishing machine for polishing the surface of the cured gypsum during the process, a polishing powder removing means, a surface treatment step consisting of a paint sprayer A method for producing a hardened gypsum body, which comprises providing an antifungal agent in the paint used and applying the antifungal agent-containing paint when the paint is applied by a paint sprayer in the surface treatment step.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a method of one embodiment of the method for producing a hardened plaster of the present invention. In the method of the present embodiment, after a drying step (not shown) in the production line of the cured gypsum, after the polishing machine 21, polishing powder removing means including a rotating brush 22, a spraying machine 23 for the undercoat paint, and the main coating paint are provided. 2 is provided, the surface of the gypsum hardened product dried by a dryer (not shown) is ground by a grinder 21 after being molded into a predetermined thickness according to the method shown in FIG. And while conveying the gypsum hardened body 20 obtained by post-processing to a predetermined thickness by the roller conveyor 25,
First, after removing the abrasive powder on the surface of the cured gypsum 20 with the rotating brush 22, an acrylic emulsion, a vinyl acetate emulsion or a polyvinyl alcohol-based water-based transparent sealer is used as the undercoat paint from the undercoat paint sprayer 23 on the surface of the cured gypsum 20. Then, the main coating composition is sprayed from the sprayer 24 onto the surface of the cured gypsum body 20.

[0017] Thus, by incorporating a step of performing main coating in addition to polishing and undercoating in the surface treatment step in the gypsum cured product production line, the surface-coated gypsum cured product of the present invention can be efficiently produced. be able to. It is also possible to incorporate a sticking device for sticking decorative paper or the like in place of the spraying machine for main coating.

In the present invention, when a small amount of the polishing powder is generated, it may be omitted. When removing the polishing powder, an adhesive roller may be used instead of the illustrated rotating brush. A device or a combination of a brush or a rotating brush and a suction device may be used. Further, a spraying machine for the main coating material is not always necessary, and when the surface of the gypsum cured product is coated or the decorative paper is stuck on site, only the undercoat coating is required. Further, instead of the main coating paint sprayer, a sticking device combining a decorative paper coated with an adhesive and a pressure roller may be used.

In the present invention, the acrylic emulsion, vinyl acetate emulsion or polyvinyl alcohol-based paint as the undercoat is usually preferably applied at a rate of 150 to 200 g per unit area (1 m ² ) of the surface of the cured gypsum. . When the main coating is applied, the main coating is usually a unit area (1 m ² ) of the surface of the cured gypsum.
It is preferable to apply at a rate of 100 to 150 g per unit.

In the present invention, an acrylic emulsion,
As a fungicide mixed in vinyl acetate emulsion or polyvinyl alcohol-based paint, an imidazole compound,
A fungicide such as a fungicide containing a halogenated aromatic compound or urea compound as a main component and soluble in water or dispersed or emulsified in water can be used. It is desirable to use it in the range of 0.03 to 1.0% with respect to the coating material. ,

The hardened gypsum of the present invention is
It is not necessary to carry out the undercoat coating and the removal treatment of the polishing powder prior to this undercoat coating, and the main coating can be directly applied or the decorative paper can be adhered to easily and easily perform the construction in a short time. In particular, as shown in FIG. 1, when the main coating is performed on the production line, the main coating work on site is not necessary, and the construction is further facilitated.

Needless to say, the present invention is not limited to the three-layer structure lightweight gypsum cured product shown in FIG. 3 and can be applied to a one-layer or two-layer structure gypsum cured product.

Since the gypsum hardened product of the present invention is an acrylic emulsion, vinyl acetate emulsion, or polyvinyl alcohol-based paint with an undercoat coating of a fungicide mixed therein, an undercoat coating on site and this undercoat are performed. It is not necessary to remove the abrasive powder prior to painting, and the number of construction man-hours can be greatly reduced, and construction can be easily performed in a short construction period. Moreover, the undercoating increases the hardness of the surface of the gypsum hardened body, and scarcely damages the surface of the gypsum hardened body during transportation or construction.

Such a gypsum hardened product of the present invention can be easily and efficiently manufactured by the manufacturing method of the present invention. In particular, in the present invention, since the undercoat coating is performed after removing the polishing powder, the adhesion strength of the undercoat coating film is high, and the action of the fungicide can suppress the generation of mold after the construction.

[0025]

The present invention will be described more specifically with reference to the following examples and comparative examples.

Example 1 Using the apparatus shown in FIG. 1, a hardened plaster of the gypsum with the undercoating and main coating shown in Table 1 was produced.

The obtained gypsum hardened product was not easily scratched during handling, and could be efficiently applied in a short time without the need for painting on site.

[0028]

[Table 1] Example 2 A gypsum hardened body was produced in the same manner as in Example 1 except that the main coating was not performed.

The obtained gypsum hardened product is less likely to be scratched during handling, and on the site, a decorative paper is directly attached,
It was possible to construct efficiently in a short time.

Example 3 To the sealer of the acrylic emulsion paint manufactured by Nippon Paint Co., Ltd. used in Example 1, the amount of the antifungal agent "Biocut" manufactured by Dainippon Ink and Chemicals, Inc. was adjusted to the coating amount shown in Table 2. The mixture was blended, and the generation of mold was observed indoors in a windless state under the same test conditions as shown in Table 2.

[0031]

[Table 2]

The state of mold development is shown in Table 2.
It was confirmed that no mold was generated when the amount of the fungicide applied was 0.05 g / m ² or more. However, considering economic efficiency, even if the coating amount is 1.00 g / m ² or more, the effect does not change, and the manufacturing cost only increases, which is considered to be a bad idea.

As described above, according to the gypsum hardened product and the method for producing the same of the present invention, since the surface hardness is high, scratches are less likely to occur during handling, and no dust is generated on site.
In addition, a gypsum hardened body that is excellent in workability and that can prevent the generation of mold even after use is provided.

[Brief description of drawings]

FIG. 1 is a side view showing an example of a method for producing a hardened plaster of the example.

FIG. 2 is a cross-sectional view showing a method for manufacturing a light-weight gypsum hardened body according to a conventional example.

FIG. 3 is a cross-sectional view of a lightweight gypsum cured product.

[Explanation of symbols]

 1,3 Outer layer 2 Intermediate layer 5 Mixer 6 Foaming machine 11 First layer 12 Second layer 13 Third layer 20 Gypsum hardened body 21 Polishing machine 22 Rotating brush 23 Undercoat paint sprayer 24 Main coating sprayer 25 Roller conveyor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naruyuki Tsuzaki 1-297 Kitabukurocho, Omiya City, Saitama Prefecture Mitsubishi Materials Corporation

Claims (4)

[Claims] 1. A gypsum cured product obtained by applying a coating of acrylic emulsion, vinyl acetate emulsion or polyvinyl alcohol paint on the surface of the gypsum cured product. 2. The surface of the hardened gypsum is polished, the polishing powder on the surface is removed, and then an acrylic emulsion, a vinyl acetate emulsion or a polyvinyl alcohol paint is applied to the surface of the hardened gypsum. Item 2. A method for producing a gypsum hardened body according to Item 1. 3. A method for producing a gypsum hardened product, which comprises a step of feeding and molding the gypsum kneaded material on a conveyor, a hardening step of hardening the gypsum kneaded material on the conveyor, and a drying step of drying the hardened material. After the drying step, a surface treatment step including a polishing machine and a paint sprayer is provided, and after the surface of the cured gypsum body is polished in the surface treatment step, an acrylic emulsion, vinyl acetate emulsion or polyvinyl alcohol is applied to the surface of the cured gypsum surface. The method for producing a gypsum hardened product according to claim 1 or 2, wherein the paint is applied with a paint sprayer. 4. An antifungal agent mixed paint prepared by mixing an antifungal agent with the acrylic emulsion, vinyl acetate emulsion or polyvinyl alcohol paint according to any one of claims 1 to 3 is applied to the surface of the hardened gypsum body. Claim 1
A cured gypsum product according to claim 3 and a method for producing the same.