Expired Canadian patentCanada
Use of block copolymers having linked siloxane blocks in the production of polyurethane foams
CA 2229295 C · Owner: Weier, Andreas · Inventors: Weier, Andreas; Langenhagen, Rolf-Dieter; Burkhart, Georg
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to the use of block copolymers having linked siloxane blocks of the general average formula (see fig. I), as additive in the production of polyurethane foams.
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 February 10, 1998 and granted June 4, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 10, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 10, 2020.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledFebruary 10, 1998
GrantedJune 4, 2002
Term endedFebruary 10, 2018
Patent numberCA 2229295 C
Classification (IPC)C08J9/04 +2 more
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.