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:
Sep. 30, 1997
Filed:
Jun. 21, 1996
Takaharu Nakano, Kumamoto, JP;
Katsuyoshi Tsuchiya, Kumamoto, JP;
Shunji Yoshimatsu, Kumamoto, JP;
Takeru Fuchigami, Kumamoto, JP;
Chisso Corporation, Osaka-fu, JP;
Abstract
A process is disclosed for producing a diorganopolysiloxane by polymerizing a cyclic siloxane expressed by the following general formula (2) ##STR1## wherein R.sup.3 represents methyl group, ethyl group, or phenyl group, and p is an integer of 3 or 4, by an anion living polymerization using a lithium trialkylsilonolate or an alkyl lithium as a polymerization initiator and then terminating the anion living polymerization with an acid or a chlorosilane derivative, the improvement comprising treating a diorganopolysiloxane which is modified with a silanol at both its terminals and included in the cyclic siloxane as impurities, with an acetylating agent.