JPS6021872A - 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 there are various types of hemihydrate gypsum, such as α-type hemihydrate gypsum, β-type hemihydrate gypsum, etc. Surfactants must be selected individually depending on the brand. However, when mixing a polyvinyl alcohol 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 spiky air bubbles may form. It is normal for bubbles to occur and have 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 on the other hand, 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. It can be added selectively.

Various additive substances "gypsum hemihydrate" according to the method of the present invention: α-type or β-type gypsum hemihydrate powder whose chemical formula is CaSO4.1/2H2O. The particle size is preferably 100 mesh or less.

"Surfactant": Any surfactant such as linear alkyl sulfate, sodium lauryl sulfate, sodium alkylaryl sulfonate, soheda 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 carbonate hydroxide, magnesium carbonate hydroxide, iron carbonate, copper carbonate, sodium carbonate, sodium potassium carbonate, lead carbonate, nickel carbonate, barium carbonate, magnesium carbonate magnesium carbonate calcium, manganese carbonate and other carbonates, tricarbonate dihydrogen tetracarbonate Carbonates of bicarbonates such as ammonium, ammonium bicarbonate, potassium bicarbonate, sodium bicarbonate, potassium magnesium bicarbonate, lithium bicarbonate.

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

"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 sulfate alum, 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 fibrous material may be used, such as pulp fiber, polyester fiber, propylene fiber, and metal fiber.

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

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

"Synthetic resin emulsion aqueous solution": polyvinyl acetate emulsion aqueous solution, polystyrene emulsion aqueous solution, polyvinyl alcohol vinyl chloride copolymer emulsion aqueous solution, 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,
Any other fiber or fibrous cloth can be used, such as synthetic fiber cloth such as acetate fiber cloth, cotton/polyester blend cloth, asbestos fiber cloth, leather cloth, synthetic leather cloth, and the like. The thickness of foamed gypsum board is 1.6
Not only those with a thickness of about 3 mm, 6 mm, and 9 mm.
mm, 12 mm, 15 mm, 20 mm, 60 mm, 100
It can be manufactured by molding boards such as mm and 120 mm. In that case, the space between two or more pieces of cloth, for example, 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., as necessary. It is also possible to manufacture the board by pouring foamed gypsum slurry into it and molding it into a board shape, and it is also possible to use gypsum board base paper (for example, glass fiber cloth) or paper instead of the cloth for the inside or center.

Next, the method of the present invention will be explained with reference to examples.

Example 1 Blended β-type gypsum hemihydrate 100 parts by weight linear alkyl sulfate 0.08 Calcium carbonate with an average particle size of 0.15 microns 0.4 10% calcium silicofluoride aqueous solution 3.6 5% Polyvinyl alcohol aqueous solution 20 Ammonium sulfate 1.2 Water 50 The additives made of the above are homogeneously stirred or mixed within 10 seconds in a mixer to form a highly fluid solution containing countless fine carbon dioxide gas bubbles. After creating the foamed gypsum slurry, it was poured into two cotton cloth molds and allowed to harden in 8 minutes. After drying at a temperature of 150°C, it was made into a 3mm thick, bulk specific gravity 0.
．． Seventy-seven foamed gypsum board moldings were manufactured.

Example 2 Formulation β-type gypsum hemihydrate 100 parts by weight Linear alkyl sulfate 0.08 Calcium carbonate with an average particle size of 0.15 microns 0.4 10% calcium silifluoride aqueous solution 3.6 5% Polyvinyl alcohol aqueous solution 20 Ammonium sulfate 1.3 Glass fiber 0.4 Water 50 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 and cured in 8 minutes. Seshime 1
After drying at a temperature of 50℃, the thickness is 1.6 mm and the bulk specific gravity is 0.80.
manufactured foamed gypsum board.

Example 2 shows that fibrous materials such as glass fibers can be used in combination.

Example 3 Formulation β-type gypsum hemihydrate 100 parts by weight Linear alkyl sulfate 0.08 Calcium carbonate with an average particle size of 0.15 microns 1.0 10% aqueous sodium silicofluoride solution 10.3 10% Calcium metasilicate aqueous solution 1.2 〃 Calcium chloride (CaCl2.2H2O) 0.8 〃 5% polyvinyl alcohol aqueous solution 20 〃 15% vinyl acetate emulsion aqueous solution 10 〃 Ammonium sulfate 1.4 Part by weight glass fiber 0.4 〃 Water 42 〃 Perform the same work as in Example 1, pour into a mold made of two polyester fiber cloths, harden in 8 minutes, dry at a temperature of 150°C, and form foamed plaster with a thickness of 60 mm and a bulk specific gravity of 0.64. Manufactured the body board. The foaming reaction is as follows.

Na2SiF6+CaSiO3+CaCO3+CaCl
2+2H2O→3CaF2↓+2H2SiO3↓+2N
aCl+CO2↑Example 3 shows that an aqueous emulsion solution such as an aqueous vinyl acetate emulsion solution or an aqueous emulsion solution of a synthetic resin can be used in combination.

As described in detail above, according to the present invention, it is possible to economically and inexpensively produce a foamed gypsum board containing fine air bubbles that has good adhesion between cloth and plaster, and therefore has industrial utility value. is extensive.

Patent applicant: Kenichi Abe

Claims (1)

[Claims] 1. The main raw material is α-type or β-type gypsum hemihydrate, and the amount of water mixed with it is a surfactant, carbonate or bicarbonate, acidic fluoride compound, polyvinyl alcohol, hardening accelerator, and gypsum hemihydrate. of water 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 then poured between cloth and formed into a board shape before curing. A method for manufacturing foamed gypsum board, which is characterized by drying.