Polymer blends for heat seamable roof sheeting and method for covering roofs
CA 2093397 C · Owner: Davis, James A. · Inventors: Davis, James A.; Valaitis, Joseph K.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A self-adhering heat seamable sheet material for roofing prepared from an uncured polymeric composition of matter which comprises 100 parts by weight of apolymer blend comprising from about 10 to 95 parts by weight of an polymer selected from the group consisting of semi-crystalline polymers having more than about 2 percent be weight crystallinity and polyolefins having up to about 2 percent by weight crystallinity, which polyolefins are prepared from monomers having at least 2 carbon atoms, and mixtures thereof; and from about 5 to 90 parts by weight of a crystallinity enhancing polymer and mixtures thereof; from about 20 to 300 parts by weight of a filler selected from the group …
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 April 5, 1993 and granted April 27, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 5, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 5, 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.