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. 13, 1982
Filed:
May. 19, 1980
Akitoshi Sugio, Ohmiya, JP;
Akira Amemiya, Tokyo, JP;
Tadashi Kunii, Yokkaichi, JP;
Tomotaka Furusawa, Matsudo, JP;
Mutsuhiko Takeda, Matsudo, JP;
Katsumasa Tanaka, Yokkaichi, JP;
Toshikazu Umemura, Tokyo, JP;
Mitsubishi Gas Chemical Co., Inc., Tokyo, JP;
Abstract
In a process for producing an oxymethylene homopolymer or copolymer having improved stability which comprises polymerizing trioxane or a mixture of trioxane and a cyclic ether and/or a cyclic acetal in bulk in the presence of a catalyst which is at least one compound selected from the group consisting of boron trifluoride, boron trifluoride hydrate and coordination compounds of boron trifluoride with organic compounds containing an oxygen or sulfur atom, the improvement which comprises performing the bulk polymerization without destroying the bulk polymerization system, or which comprises adding a tertiary phosphine compound to the polymerization system to deactivate the catalyst, before the polymerization system formed by the bulk polymerization is destroyed.