WATER-RESISTANT HYDRAULIC INORGANIC COMPOSITION, ITS PRODUCTION AND WATER-RESISTANT GYPSUM BOARD

摘要

PROBLEM TO BE SOLVED: To provide a method for obtaining a hydraulic inorganic composition capable of eliminating problems of a conventional hydraulic inorganic composition, excellent in water resistance without impairing properties such as fire retardant properties, etc., which a hydraulic inorganic substance essentially has and to obtain a gypsum board having high water resistance. SOLUTION: This water-resistant hydraulic inorganic composition comprises (A) a partially or completely neutralized substance of a copolymer of a vinyl compound and an unsaturated dicarboxylic acid or its anhydride having 200-500 acid value or its derivative and (B) an organosiloxane having a hydrogen atom bonded to a silicon atom. The method for producing the water-resistant hydraulic inorganic composition comprises blending an emulsified liquid obtained by emulsifying the component A and the component B in the weight ratio of 20:1 to 1:20 in the presence of an alkali compound in water with a hydraulic inorganic composition. The water-resistant gypsum board is obtained by the method.