| 摘要 |
PURPOSE:To provide fibrous calcium potassium silicate exhibiting ion eaxchangeability due to K2O contained in the molecule by subjecting potassium silicate and a water sol. Ca cpd. to hydrothermal reaction under press. CONSTITUTION:An aq. soln. of potassium silicate (A) pref. having the molar ratio of SiO2/K2O 2.5-3.7 is mixed with an aq. soln. of a water sol. Ca cpd. (B) such as Ca(OH)2 or CaCl2. The concn. of the component (A) is pref. 0.3-2.0 mols/l, the concn. of the component (B) 0.1-0.4 mol/l, and the component (A) is used in excess to the component (B). The mixed aq. soln. is then subjected to hydrothermal reaction at 150-250 deg.C under usual vapor press. to produce fibrous calcium potassium silicate. By contacting the fibrous silicate to an aq. soln. of NaCl or the like K2O can be ion exchanged for Na2O. |
