Process for the preparation of polyamide prepolymers
CA 2022032 A1 · Owner: Bp Chemicals Limited · Inventors: Studholme, Matthew B.; Taylor, Stephen A.; Orpin, Murray R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to a process for producing polyamide prepolymers having a number average molecular weight of 3000 to 5000 by condensation of solid nylon salts formed from dicarboxylic acids and diamines in stoichiometric amounts characterised in that the condensation is carried out in the presence of a catalyst under the influence of heat and vacuum in an extruder. These prepolymers can be used as feedstock for producing high molecular weight polyamides which in turn can be fabricated into articles such as films, pipes etc.
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 July 26, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 26, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 26, 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.