GYPSUM HARDENED BODY, GYPSUM PLATE, PRODUCTION METHOD OF GYPSUM HARDENED BODY, PRODUCTION METHOD OF GYPSUM BOARD

摘要

PROBLEM TO BE SOLVED: To provide a gypsum hardened body having small specific gravity and including an inorganic material-made strength improver not affecting fire retardancy.SOLUTION: The production method of a gypsum hardened body having a specific gravity of 0.3 to 0.8 is provided which comprises: a gypsum slurry production step of producing a gypsum slurry by kneading plaster, calcium hydrogen phosphate dihydrate, water and foam; a molding step of molding the gypsum slurry; and a hardening step of hardening a molded body obtained in the molding step. The gypsum slurry contains the calcium hydrogen phosphate dihydrate at a percentage of 0.01 to 5 pts.mass based on 100 pts.mass of the plaster and further contains organic carboxylic acid and/or organic carboxylate.