| 摘要 |
PURPOSE:To obtain a water-repellent gypsum wallboard having improved water resistance and water proofing property by preparing this wallboard from a gypsum compsn. containing methylhydrodiene polysiloxane, gypsum and one kind selected from cement, calcium silicate hydrate, magnesium oxide and magnesium hydroxide, and board base paper. CONSTITUTION:The gypsum compsn. is prepared by adding 0.2-5 pts.wt. methylhydrodiene polysiloxane and 0.1-10 pts.wt. of at least one of cement, calcium silicate hydrate, magnesium oxide and magnesium hydroxide to 100 pts.wt gypsum. The methylhydrodiene polysiloxane is used in an emulsion state, and polyvinylalcohol may be used as an emulsifier. In the production of the gypsum wallboard, a slurry is prepared by mixing a specified amt. of the source material such as gypsum, methylhydrodiene polysiloxane, cement calcium silicate hydrate with water and then the slurry is poured into the space between board base sheets by a conventional method. |
