Polyglutarimides with improved properties in poly(vinyl chloride)
CA 2058573 A1 · Owner: Cohen, Leslie A. · Inventors: Freed, William T.; Fromuth, Harry C.; Cinoman, Douglas S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Polyglutarimides, such as those prepared by reaction in the melt of poly(alkyl methacrylates) with ammonia or primary amines exhibit, in, blends with poly(vinyl chloride) improved thermal stability properties, such as lower color, as well as lowered content of non-aqueous volatiles such as, trimethylamine, when the molten polyglutarimide is carefully devolatilized to lower the volatile amine content below 50 ppm.
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 30, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 30, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 30, 2013.
- 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.