Heat resistant polymers and blends of hydroquinone poly(iso-terephthalates)containing residues of p-hydroxybenzoic acid
CA 2000474 C · Owner: Bp Amoco Corporation · Inventors: Huspeni, Paul Joseph; Layton, Richard; Matzner, Markus
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention pertains to novel copolyesters consisting essentially of units (I) (II), (III), and (IV). , (I) (II), , (III) (IV) and blends of these polymers and articles made from both. Units (I) (II), (III), and (IV), are present in specified proportions as defined in the "Description of the Invention." The instant copolyesters display orientation in the molten state good fiber ratings and, high strength; they have melting points in the range of from about 340 to about 400°C and are melt-processible. Advantageously, these compositions filled with about 30 weight percent of glass fibers display heat distortion temperatures of over 240°C up to about 280°C and higher when measured under a …
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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 October 11, 1989 and granted November 5, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 11, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 11, 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
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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.