Polyetheric copolymers, process for preparing the same, compositions containing the same, their molded products, and their use
CA 2005563 C · Owner: Chino, Shinji · Inventors: Matsuo, Shigeru; Murakami, Shigeru; Yako, Naoto
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a polyetheric copolymer, a polyetheric block copolymer and compositicns of these copolymers containing a benzonitrile recurring unit represented by the general formula (I):, and a benzophenone recurring unit represented by the general formula (II):, which copolymer has a molar ratio of the recurring unit of formula (I) to a sum of the recurring units of formulas (I) and (II) in the range from 0.15:1 to 0.40:1, and a melt viscosity (zero shear viscosity) at 400°C in the range from 500 to 100,000 poise. The polyetheric copolymer according to the invention is crystalline and is a macromolecular compound having excellent heat resistance and mechanical strength.
Read the whole patent
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 14, 1989 and granted December 9, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 14, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 14, 2011.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.