Process for the preparation of composite bodies
CA 2135289 A1 · Owner: Grammes, Hartwig · Inventors: Grammes, Hartwig; Wegener, Dirk; Liman, Ulrich
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for making composites by coating the reverse of a plastic film as the top layer with a reaction mixture reacting to form a soft or semi-hard polyurethane foam consisting essentially of a polyisocyanate component, a polyol component at least one, blowing agent, catalysts and possibly other auxiliaries and additives, in which reaction products in alkaline salt form of (i) at least trivalent alcohols in the molecular weight range from 92 to 1,000 and (ii) intramolecular carboxylic acid anhydrides having a statistical mean per molecule of at least 2 alcoholic hydroxyl groups and at least 0.5 alkaline carboxylate groups are used as catalysts, and composites made by this process.
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 May 26, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 26, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 26, 2015.
- 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.