Triblock copolymers incorporating a styrene/isoolefin copolymer midblock
CA 2355317 A1 · Owner: Exxonmobil Chemical Patents Inc. · Inventors: Wang, Hsien-Chang; Shaffer, Timothy D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Novel triblock copolymers are provided. The triblock copolymers have a midblock which is a copolymer of an isoolefin monomer and a vinyl aromatic monomer. Preferably, the midblock is a copolymer of isobutylene and alkylstyrene. The end blocks of the triblock copolymer are either a homopolymer of a vinyl aromatic monomer or a copolymer of two or more monomers selected from the group consisting of vinyl aromatics styrene, methylstyrene, butylstyrene, halostyrene p-allylstyrene and p-3-butenylstyrene. In addition a process is provided for preparing a triblock copolymer. The process involves: a) initiating a "living" polymerization of an isoolefin monomer (monomer A) and a first vinyl …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed December 1, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 1, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 1, 2021.
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.