Roofing material containing non-leachable fire retardant
CA 2000341 C · Owner: Lo, Chun Y. · Inventors: Lehtinen, Thomas A.; Lo, Chun Y.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A fusible phenolic resin and a dialkyl-N N-bis (hydroxyalkyl), aminoalkyl phosphonate are condensed to form a water-insoluble resin having fire retardant properties. Fire resistant materials are made by causing the condensation to occur in situ when a normally flammable material and the reactants are mixed and the mixture is heated at 250°F to 480°F. Wooden articles such as molded hardboard roofing shingles of this invention do not lose their fire resistance after being soaked with rain repeatedly.
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 October 10, 1989 and granted July 8, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 10, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 10, 2011.
- 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.