The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 23, 2016
Filed:
Mar. 01, 2011
Shuji Tanaka, Niigata, JP;
Masaki Tabata, Niigata, JP;
Shuji Tanaka, Niigata, JP;
Masaki Tabata, Niigata, JP;
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Abstract
A mixture containing methyldichlorosilane, tetrachlorosilane, and trichlorosilane is distilled to fractionate a fraction with a higher content of methyldichlorosilane than the mixture before distillation. Subsequently, the fraction thus fractionated is heated to disproportionate chlorine between methyldichlorosilane and tetrachlorosilane to disproportionate methyldichlorosilane into methyltrichlorosilane. Subsequently, the fraction after disproportionation containing methyltrichlorosilane is purified by distillation to separate high-purity trichlorosilane. Having a close boiling point to that of trichlorosilane (32° C.), which is a target product to be purified by distillation, removal of methyldichlorosilane (boiling point of 41° C.) has been difficult. The present invention removes methyldichlorosilane more easily by converting it into methyltrichlorosilane (boiling point of 66° C.) through disproportionation of chlorine between methyldichlorosilane and tetrachlorosilane.