Preparation of flexible polyurethane foams having low compressive strength and block polyoxypropylene polyoxyethylene polyol mixtures which can be used for this purpose
CA 2031909 C · Owner: Lugmayr, Michael · Inventors: Hinz, Werner; Peters, Reinhard; Leppkes, Reinhard
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Flexible polyurethane foams having low compressive strength and relatively good tensile strength are prepared by reacting, a) a block polyoxypropylene-polyoxyethylene-polyol mixture which has a hydroxyl number of from 14 to 65 contains from 2 to 9% by weight, based on the weight of the polyoxypropylene units, of ethylene oxide units bonded in the terminal position and is prepared by anionic polymerization of the alkylene oxides with an initiator mixture having an average functionality of from 2.3 to 2.8 and consisting of water and glycerol and/or trimethylolpropane, or a mixture of these block polyoxypropylene-polyoxyethylene-polyol mixtures with bi- and/or trifunctional …
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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.
- 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.