Substituted polybutadiene polymer and roofing membrane formed therefrom
CA 2072284 C · Owner: Davis, James A. · Inventors: Mcgillvary, Daniel R.; Hergenrother, William L.; Davis, James A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A substituted polybutadiene polymer and a composition containing the polymer which is suitable for use in a flat sheet material such as a roofing membrane is disclosed. The polymer has a superior filler capacity, excellent flame resistivity and acceptable heat aging properties, especially heat aged elongations. The composition, which includes the polymer of the present invention and from about 5 to about 160 parts by weight of a filler material per 100 parts polymer is self-adhering, without the use of an adhesive and is heat seamable to produce seams which are resistant to temperatures as high as 100~C.
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 June 25, 1992 and granted September 15, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 25, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 25, 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.
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.