JPS6021877A - 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, surfactants are used as foaming aids when manufacturing gypsum boards, but types of hemihydrate gypsum, such as α-type hemihydrate gypsum, β-type hemihydrate gypsum, and other brands The surfactant must be selected individually depending on the 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 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 carbonate gypsum foam 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. 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.

"Fatty acid salts": (excluding alkali metal fatty acid salts) barium laurate, zinc laurate, lead laurate, magnesium laurate, calcium laurate, zinc palmitate, cobalt palmitate, lead palmitate,
Magnesium palmitate Manganese palmitate, Zinc oleate, Cobalt oleate, Lead oleate, Magnesium oleate, Manganese oleate, Tin stearate, Zinc stearate, Cobalt stearate, Lead stearate, Zirconium stearate, Aluminum stearate, Lower fatty acid salts and higher fatty acid salts such as calcium stearate, cadmium stearate, barium stearate, magnesium stearate, and manganese stearate.

"Carbonate or bicarbonate carbonate": 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, etc.
Carbonates of bicarbonates such as carbonate, tetraammonium dihydrogen tricarbonate, ammonium hydrogen carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate, potassium magnesium hydrogen carbonate, lithium hydrogen carbonate.

"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 hydrosilicic acid aqueous solution, hydrofluoric acid aqueous solution, 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 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 1.2% 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 (e.g. calcium metasilicate and dicalcium silicate, etc.), barium silicate salts, lead silicate salts,
Magnesium silicate salt, manganese silicate salt, magnesium calcium metasilicate salt, etc.

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

As the base paper for gypsum board used in the method of the present invention, base paper for gypsum board, asbestos paper (with pulp content of 20% or less), glass fiber cloth, other craft paper, paper mixed with glass fiber, Japanese paper, Western paper, etc. may be used. Can be done.

The thickness of carbonate gypsum foam board is of course around 1.6 mm, but also 3 mm, 6 mm, 9 mm, 12 mm, 15 mm, 20 mm, 60 mm, 100 mm and 1 mm.
It can be manufactured by molding a board of 20 mm or the like.

In that case, if necessary, it is also possible to pour foamed gypsum slurry between two or more sheets of paper, for example between three sheets of paper, and mold it into a board shape. For example, polyester fiber cloth) 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 Calcium stearate 0.015 Average particle size
0.15 micron calcium carbonate 0.4 〃 10% calcium silicofluoride aqueous solution 3.6 〃 5% polyvinyl alcohol aqueous solution 20 〃 Ammonium sulfate 1.2 〃 Water 50 〃 The above compounded additives were placed in a mixer. Stir or mix homogeneously within 10 seconds to create a highly fluid foamed gypsum slurry containing countless microscopic carbon dioxide gas bubbles, then pour this into a mold made of two sheets of gypsum board base paper for approximately 6 seconds. After curing in 5 minutes and drying at a temperature of 150℃, 1
A molded product of carbonate gypsum foam board with a thickness of 2 mm and a bulk specific gravity of 0.84 was manufactured.

Example 2 Blend β-type gypsum hemihydrate 100 parts by weight Barium laurate 0.02 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 1.3 〃 Glass fiber 0.4 〃 Water 50 〃 Perform the same operation as in Example 1, and prepare two glasses. Pour into the fiber cloth mold and cure in 7 minutes at 150℃.
A carbonate gypsum foam board with a thickness of 3 mm and a bulk specific gravity of 0.83 was produced after drying at a temperature of .

Example 3 Blend β-type gypsum hemihydrate 100 parts by weight Calcium stearate 0.02 Average particle size 0
．． 15 micron calcium carbonate 1.0 〃 10% sodium silicofluoride aqueous 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 〃 Water 42 Parts by weight Perform the same operation as in Example 1, pour into two sheets of kraft paper mold, harden for 8 minutes, and heat to 150°C. After drying at a temperature of , a carbonate gypsum foam board with a thickness of 3 mm and a bulk specific gravity of 0.66 was produced. 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 can be used in combination. As described above, according to the present invention,
Since it is possible to produce carbonate gypsum foam board containing fine air bubbles with good adhesion between gypsum board base paper or paper and gypsum at low cost, it has a wide range of industrial utility values.

Patent applicant: Kenichi Abe

Claims (1)

[Claims] 1. The main raw material is α-type or β-type gypsum hemihydrate, which contains fatty acid salts (excluding fatty acid salts of alkali metals), carbonates of carbonates or bicarbonates, acidic fluoride compounds, polyvinyl alcohol, and hardening accelerators. Add the same amount of water as the agent and gypsum hemihydrate, stir or mix homogeneously in a mixer to create a highly fluid gypsum foam slurry containing countless carbon dioxide microbubbles, and mix this with gypsum board base paper or A method for producing carbonated gypsum foam board, which is characterized by pouring it between sheets of paper, forming it into a board shape, and then hardening and drying it.