| 摘要 |
PROBLEM TO BE SOLVED: To provide a stable transparent aqueous solution of sodium silicate having an SiO<SB>2</SB>/Na<SB>2</SB>O (molar ratio) in the range of 5 to 8 and to provide a method for producing the same. SOLUTION: An overlay-fitted stainless beaker is charged with 100 g of white carbon, 42 g of 48% NaOH, and 200 g of water, and the contents are heated in steam of 80°C for 2 hr and then cooled to room temperature. This results in the formation of transparent water-glass-like composition. An analysis of the resulting composition shows that the weight ratio of SiO<SB>2</SB>to the entire composition is 30.1%, and the weight ratio of Na<SB>2</SB>O to the entire composition is 6.0%. The SiO<SB>2</SB>/Na<SB>2</SB>O (molar ratio) is 5.17. The composition is stable because the precipitation of silica is not observed when the composition is stored in a thermostatic chamber at 25°C for half a year. COPYRIGHT: (C)2006,JPO&NCIPI |
