| 摘要 |
PURPOSE:To prevent occurrence of luster unevenness on the surface by heating and hardening a hardening mixture composed of an aqueous solution of an alkali metal silicate and a hardening agent to give a hardened inorganic body, treating the hardened inorganic body with an aqueous solution of an alkaline earth metal neutral salt. CONSTITUTION:100 pts.wt. of 10-80wt.% aqueous solution of an alkali metal silicate of the formula SiO2.nM2O (M is alkali metal; n is 0.5-4) is mixed with 20-250 pts.wt. of a hardening agent such as SiO2-Si2O3-based amorphous powder, <=1,500 pts.wt. of an inorganic filler of such as silica sand, <=30 pts.wt. of reinforcing fibers having 1-25mm fiber length such as PP and <=150 pts.wt. of light aggregate such as perlite, molded, maintained at 50-300 deg.C for 5 minutes to 12 hours to form a hardened inorganic body. Then, the hardened inorganic body is immersed in an aqueous solution of an alkaline earth metal such as CaCl2 having pH5-7 and 0.05 concentration to saturated concentration for 5 minutes to 48 hours to give a hardened inorganic body free from occurrence of luster unevenness and tack on the surface. |
