Patent ID: 7841211
Filing Date: 2010-11-30
Classification: C03B,C03C

Abstract:
1. A production process of a highly heat-resistant synthetic quartz glass having an absorption coefficient at 245 nm of 0.05 cm −1 or more, comprising the steps in the sequence set forth: preparing a silica porous body, conducting a reduction treatment to the silica porous body in an atmosphere containing a reducing gas at a reaction temperature of 100° C. or higher and 1,300° C. or lower for 30 minutes or more, conducting a baking treatment to the silica porous body at a reaction temperature of 1,300° C. or higher and 1,900° C. or lower, thereby forming a dense glass body having an absorption coefficient at 245 nm of 0.05 cm wherein said reducing gas is a volatile silicon compound containing nitrogen and/or carbon, and said volatile silicon compound is at least one kind of compound selected from the group consisting of an organosiloxane, an alkoxysilane, an aroxysilane, an organosilane, and an organopolysilane and wherein the dense glass body has a natural logarithmic value of viscosity at 1280° C. in an approximate range of 11.7 and 12.4.