Foams having increased heat distortion temperature made from blends of alkenyl aromatic polymers and alpha-olefin/vinyl or vinylidene aromatic and/or sterically hindered aliphaticor cycloaliphatic vinyl or vinylidene interpolymers
CA 2353098 A1 · Owner: Cirihal, Stephanie C. · Inventors: Chaudhary, Bharat I.; Barry, Russell P.; Cirihal, Stephanie C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention pertains to improved alkenyl aromatic polymer foams (and processes for their preparation) having increased heat distortion temperature and improved dimensional stability while maintaining good tensile/tear creep , and environmental dimensional change properties. The closed cell low density alkenyl aromatic polymer foams exhibit increased heat distortion temperature when substantially random interpolymers of 21 to 65 mol percent styrene are blended in. When these same alkenyl aromatic polymer foams are made without these interpolymers, the heat distortion temperature is not improved.
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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 November 15, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 15, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 15, 2021.
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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.