Low-density, water-blown, rigid polyurethane foams having good physical properties and improved initial surface friability
CA 2105408 C · Owner: Lee, Thomas B. · Inventors: Lee, Thomas B.; Krueger, David C.
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 low density water-blown, rigid foams with good, physical properties made with blends of toluenediamine (TDA)/glycerine initiated polyols. The foams made using these blends exhibit no initial surface friability. Further it was found, that specific blends of lower hydroxyl number polyols could be used thereby reducing, isocyanate consumption without affecting the physical properties of the foam. 16
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 September 2, 1993 and granted October 20, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 2, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 2, 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.