Block copolymer, method of making the same, diamine precursors of the same, method of making such diamines and end products comprising the block copolymer
CA 2007162 C · Owner: Leir, Charles M. · Inventors: Leir, Charles M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Block copolymers having a repeating unit comprised of polysiloxane and urea segments are prepared by copolymerizing certain diaminopolysiloxanes with diisocyanates. The invention also provides novel diaminopolysiloxanes useful as precursors in the preparation of the block copolymers and a method of making such diaminopolysiloxanes. Pressure sensitive adhesive compositions comprising the block copolymer are also provided as are sheet materials coated with the same.
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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 January 4, 1990 and granted March 14, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 4, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 4, 2012.
- 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.