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:
Jul. 21, 2009
Filed:
Oct. 26, 2006
Hisashi Shimizu, Annaka, JP;
Toshio Shiobara, Annaka, JP;
Tsutomu Kashiwagi, Annaka, JP;
Shin-Estu Chemical Co., Ltd., Tokyo, JP;
Abstract
Provided is a method of producing a high molecular weight organopolysiloxane with a polystyrene equivalent weight average molecular weight of at least 5×10, comprising the steps of producing an organopolysiloxane by subjecting a silane compound having a hydrolyzable group to a first hydrolysis and condensation, and then subjecting that organopolysiloxane to an additional second hydrolysis and condensation. The high molecular weight organopolysiloxane is stable, resistant to gelling, and resistant to cracking even when formed as a thick film. A resin composition comprising the high molecular weight organopolysiloxane and a condensation catalyst is useful for sealing an optical element and for producing an optical semiconductor device.