Production of chlorofluorocarbon-free, urethane-containing moldings having a cellular core and a compacted peripheral zone
CA 2074138 C · Owner: Basf Aktiengesellschaft · Inventors: Mueller, Ulrich; Tintelnot, Dieter; Hoelderich, Wolfgang
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for the production, of fluorochlorocarbon-free urethane-containing, soft-, elastic, semirigid or rigid moldings having a cellular core and a compacted peripheral zone and an essentially pore-free, smooth surface involves reacting a) an organic and/or modified organic polyisocyanate with, b) at least one relatively high-molecular-weight compound containing at least two reactive hydrogen atoms, and, if desired, c) a low-molecular-weight chain extender and/or crosslinking agent, in the presence of, d) a blowing agent e) a catalyst, f) at least one amorphous microporous silica gel which, preferably has a mean pore diameter with a frequency of occurrence of more than 40 % in the range …
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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 July 17, 1992 and granted February 11, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 17, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 17, 2014.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.