PURPOSE: To easily obtain very finely grained SiO2 having a desired value of BET specific surface area within a specified range without corroding an apparatus by controlling the partial pressure of introduced water to a specified range and hydrolyzing SiCl4 in an atmosphere where a combustible gas is burned perfectly.
CONSTITUTION: When SiCl4 is hydrolyzed in an atmosphere where a combustible gas is burned perfectly, the partial pressure of water introduced into the hydrolysis reaction system is controlled to 0.02W0.5atm. By utilizing the correlation between the partial pressure of water and the BET specific surface area of a very finely grained product, very finely grained anhydrous silica having ≥50, preferably 380W50m2/g BET specific surface area is manufactured. Thus, very finely grained SiO2 having the desired BET specific surface area is easily obtd. by using easily available SiCl4 producing no highly corrosive HF as starting material.
TERAI KENJI
NIWA TAKASUMI
ODA TETSUYA
| JPS55104912A | 1980-08-11 |