| 摘要 |
PROBLEM TO BE SOLVED: To obtain a gypsum hardened body excellent in water repellency, antifouling property, dimensional stability and mechanical strength in a wet state by incorporating gypsum, a polyvinyl alcohol resin and a fluorine compound. SOLUTION: Gypsum such as hemihydrate gypsum or anhydrous gypsum, a polyvinyl alcohol resin preferably having >=70 mol%, in particular 80-99.5 mol% saponification degree and an average polymerization degree of 200-3,000, a fluorine compound, preferably a water-soluble fluorine compound and water are kneaded and the resulting slurry is hardened, or the gypsum, the polyvinyl alcohol resin and water are kneaded, the resulting slurry is hardened and the fluorine compound is applied to or impregnated into the surface of the hardened body to obtain the objective gypsum hardened body preferably containing 100 pts.wt. gypsum, 1-30 pts.wt. polyvinyl alcohol resin and 1-5 pts.wt. fluorine compound based on 100 pts.wt. polyvinyl alcohol resin. |
