JPS6021879A - Manufacture of carbonate gypsum foamed body 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] Conventionally, when manufacturing gypsum board, a surfactant is used as a foaming aid, but other types of gypsum such as α-type hemihydrate gypsum, β-type hemihydrate gypsum, etc. The surfactant must be selected individually depending on the However, when mixing a synthetic resin emulsion aqueous solution with additives such as gypsum hemihydrate and a hardening accelerator using only a surfactant, the fine air bubbles in the expanded slurry may become coarser or become spiky. It is normal for this to occur, resulting in a non-uniform bubble density. Therefore, in order to alleviate this phenomenon, it is necessary to increase the expansion coefficient and reduce the specific gravity of the slurry, but this poses a manufacturing problem in that the compressive strength of the gypsum decreases. The present inventor has conducted research in view of this point and has attempted to eliminate the drawbacks of conventional manufacturing methods. More specifically, the bulk specific gravity of the foamed gypsum board produced by the method of the present invention is within the range of 1.3 or less, and the various additives used and blended are as follows. These can be added selectively.

Various additives according to the method of the present invention, ``half gypsum'': α-type or β-type hemihydrate gypsum powder whose chemical formula is CaSO4.1/2H2O, and the particle size is preferably 100 mesh or less.

"Surfactant": Any surfactant such as linear alkyl sulfate, sodium lauryl sulfate, sodium alkylaryl sulfonate, sodium dodecylbenzenesulfonate, sodium lignin sulfonate, alkali metal salts of fatty acids, etc. good.

"Carbonates of carbonates or bicarbonates": zinc carbonate, ammonium carbonate, cadmium carbonate, potassium carbonate, potassium sodium carbonate, calcium carbonate, chromium carbonate, cobalt carbonate, cobalt hydroxide carbonate, copper hydroxide carbonate, lead hydroxide carbonate , nickel hydroxide carbonate, magnesium hydroxide carbonate, iron carbonate, copper carbonate, sodium carbonate, sodium potassium carbonate, lead carbonate, nickel carbonate, barium carbonate, magnesium carbonate, magnesium carbonate calcium carbonate, manganese carbonate, and other carbonates; Tetraammonium hydrogen, ammonium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate,
Carbonates of bicarbonates such as potassium magnesium bicarbonate and lithium bicarbonate.

"Acidic fluoride compounds": silicofluoride salts such as sodium silicofluoride, calcium silicofluoride, potassium silicofluoride, zinc silicofluoride, lead silicofluoride, ammonium silicofluoride, and barium silicofluoride salts, Acidic fluoride compounds or acidic fluorides, such as hydrosilicic acid aqueous solution, hydrofluoric acid aqueous solution, acidic sodium fluoride, and acidic potassium fluoride.

"Synthetic resin emulsion aqueous solution": polyvinyl acetate emulsion aqueous solution, acrylic acid ester copolymer emulsion aqueous solution, polystyrene emulsion aqueous solution, styrene-butadiene copolymer emulsion aqueous solution, polyvinyl alcohol vinyl chloride copolymer emulsion aqueous solution, other synthesis Any aqueous emulsion solution of resin may be used.

"Polyvinyl alcohol": An aqueous polyvinyl alcohol solution prepared to a concentration of 5 to 10% by weight is used, but powdered polyvinyl alcohol can also be used.

"Hardening accelerator": Sulfates such as ammonium sulfate, potassium alum sulfate, magnesium sulfate, silicic substances, and animal colloid substances.

"Waterproofing agent": Paraffin emulsion aqueous solution or asphalt emulsion aqueous solution, etc. Waterproofing can be achieved by adding 2% by weight or less in terms of solid content (dry weight).

"Fiber materials": glass fibers, silica fibers, carbon fibers,
Any fiber material may be used, such as pulp fiber, polyester fiber, propylene fiber, and metal fiber.

"Silicate": Calcium silicate salts (for example, calcium metasilicate and dicalcium silicate, etc.), barium silicate salts, lead silicate salts, magnesium silicate salts, manganese silicate salts, magnesium calcium metasilicate salts, etc.

"Chloride": Calcium chloride, barium chloride, magnesium chloride salt, lead chloride salt, ammonium chloride salt, etc.

Fabrics used in the method of the present invention include natural fiber cloths such as cotton fiber cloth, linen fiber cloth and pure wool fiber cloth, chemical fiber cloth such as rayon fiber cloth, carbon fiber cloth, acrylonitrile fiber cloth, polypropylene fiber cloth, polyester fiber cloth. , nylon fiber cloth,
Synthetic fiber cloth such as acetate fiber cloth, blended fiber cloth of cotton and polyester, blended fiber cloth of cotton and nylon, asbestos fiber cloth, leather cloth, synthetic leather cloth, and any other fiber or fibrous cloth can be used. can do.

The thickness of foamed gypsum board is of course around 1.6 mm, but also 3 mm, 6 mm, 9 mm, 12 mm, etc.
It can be manufactured by molding foamed gypsum boards of 15 mm, 20 mm, 60 mm, 100 mm, 120 mm, etc. In that case, if necessary, between two or more pieces of cloth, e.g.
It is manufactured by pouring foamed gypsum slurry between two pieces of cloth, between three pieces of cloth, between four pieces of cloth, between five pieces of cloth, between six pieces of cloth, etc. and molding it into a board shape. It is also possible to use gypsum board paper (e.g.
Glass fiber cloth) or paper can also be used. Next, the method of the present invention will be explained with reference to examples.

Example 1 Blend β-type gypsum hemihydrate 100 parts by weight Linear alkyl sulfate 0.08 Calcium carbonate with average particle size of 0.15 microns 0.4 10% calcium silicofluoride aqueous solution 3.6 15% A vinyl acetate emulsion aqueous solution of 10 parts by weight ammonium sulfate 1.2 〃 Water 60 〃 The blended additives consisting of the above are homogeneously stirred or mixed within 10 seconds in a mixer to form a fluid containing countless fine carbon dioxide gas bubbles. After creating a foamed gypsum slurry with good properties, it was poured into a mold made of two pieces of cotton cloth and cured in 8 minutes. After drying at a temperature of 150°C, a foamed gypsum body with a thickness of 12 mm and a bulk specific gravity of 0.81 was created. Manufactured board moldings.

Example 2 Blend β-type gypsum hemihydrate 100 parts by weight Linear alkyl sulfate 0.08 Average particle size 0.15 microns Calcium carbonate 0.4 10% calcium silicofluoride aqueous solution 3.6 15% 10 parts by weight of vinyl acetate emulsion solution Ammonium sulfate 1.3 parts by weight Glass fiber 0.4 parts by weight Water 60 parts The same procedure as in Example 1 was carried out, and the mixture was poured into a mold made of two pieces of cotton and polyester blend fabric. Harden in 1 minute
After drying at a temperature of 50° C., a foamed gypsum board with a thickness of 9 mm and a specific gravity of 0.82 was produced.

Example 3 Blend β-type gypsum hemihydrate 100 parts by weight Linear alkyl sulfate 0.08 Calcium carbonate with average particle size of 0.15 microns 1.0 10% sodium silifluoride aqueous solution 10.3 10% Calcium metasilicate aqueous solution 1.2 Calcium chloride (CaCl2.2H2O) 0.8 15% vinyl acetate emulsion aqueous solution 10 5% by weight aqueous polyvinyl alcohol solution 20 Ammonium sulfate 1.4 Water 42 Examples Perform the same procedure as in step 1, pour into two polyester fiber cloth molds, harden in 8 minutes, and dry at 150°C to produce a foamed gypsum board with a thickness of 60 mm and a bulk specific gravity of 0.65. did. The foaming reaction is as follows. The foaming reaction is as follows.

Na2SiF6+CaSiO3+CaCO3+CaCl
2+2H2O→3CaF2↓+2H2SiO3↓+2N
aCl+CO2↑Example 3 shows that it can be carried out in combination with a polyvinyl alcohol aqueous solution. As described in detail above, according to the present invention, it is possible to economically and inexpensively manufacture a foamed gypsum board containing fine air bubbles that has good adhesiveness between cloth and plaster, and therefore has industrial value. is extensive.

Patent applicant: Kenichi Abe

Claims (1)

[Claims] 1. The main raw material is α-type or β-type gypsum hemihydrate, which contains a surfactant, carbonate or bicarbonate carbonate, an acidic fluoride compound, an aqueous emulsion solution of synthetic resin, a hardening accelerator, and gypsum hemihydrate. A mixed amount of water is added and stirred or mixed homogeneously in a mixer to create a highly fluid foamed gypsum slurry containing countless microscopic carbon dioxide gas bubbles, which is poured between cloth and formed into a board shape. A method for producing a foamed gypsum board, characterized by post-curing and drying.