Preparation of flexible, soft polyurethane foams having viscoelastic, structure-borne soundproofing properties, and polyoxyalkylene-polyol mixtures which can be used for this purpose
CA 2031910 C · Owner: Hinz, Werner · Inventors: Hinz, Werner; Decker, Walter; Haase, Volker
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates, to a process for the preparation of flexible soft, polyurethane foams having viscoelastic structure-borne, sound-proofing properties in a temperature range of from -20°C to +80°C by reacting, a) a polyoxyalkylene-polyol mixture containing ai) block polyoxypropylene-polyoxyethylene-polyol mixture having a hydroxyl number of from 14 to 65 and containing from 2 to 9 % by weight of terminal ethylene oxide units, based on the weight of the polyoxypropylene units, prepared by anionic polymerization, at elevated temperatures, of 1,2-propyleneoxide onto an initiator molecule mixture having a mean functionality of from 2.3 to 2.8, comprising water and ylycerol and/or …
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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 December 10, 1990 and granted June 2, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 10, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 10, 2012.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.