摘要:
A method for producing a high purity synthetic quartz powder, characterized by using a tetramethoxysilane having a trimethoxymethylsilane content of at most 0.3 wt %, and converting it to a synthetic quartz by a sol-gel method.
摘要:
A synthetic quartz powder obtained by calcining a powder of silica gel, characterized in that white devitrification spots having sizes of larger than 20 &mgr;m in diameter formed in an ingot obtained by vacuum melting the synthetic quartz powder at a temperature of from 1780 to 1800° C. to form an ingot, followed by maintaining the ingot at a temperature of 1630° C. for 5 hours, are at most 10 spots/50 g.
摘要:
A polyalkoxysiloxane of the following rational formula: SiOa(OR)b(OH)c wherein R is a C1-4 alkyl group, a=0.86 to 1.30, b=2.18 to 1.30, and c≦0.10.