PURPOSE: To produce a glass tube having homogeneity and high purity at a low energy cost by gelling a liquid material contg. a hydrolyzable silicon compd. while rotating the same in a cylindrical vessel then drying the same and vitrifying the material by sintering the same.
CONSTITUTION: Mixed solns. 2 prepd. by contg. a silicon compd. which forms silica by hydrolysis such as silicon alkoxide, and further adding methanol, ammoniac water, etc., thereto are put into a vessel 1 having a cylindrical inside surface such as glass tube, and both ends are sealed with aluminum foil or the like, then the vessel is rotated in the direction of an arrow 3. Then the mixed solns. stick uniformly on the inside wall of the vessel 1' and gel, thus forming a tubular wet gel 4. Pinholes are opened in the aluminum foil and the tube is heated gradually to dry the wet gel, whereby a dried gel 5 of a cylindrical shape is obtained. The dried gell 5 is removed and is vitrified by sintering at temp. lower than the melting temp. in an electric furnace, whereby the uniform quartz glass tube of high purity is obtained irrespectively of wall thicknesses.
MATSUYAMA IWAO
SATOU MAKOTO
SUGANUMA YASUO
HITACHI CABLE