Process to produce tack-free rubber particles
CA 2036083 C · Owner: Shell Canada Limited · Inventors: Gorman, John E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process to produce a free flowing fine polymer powder is provided. The process comprises the steps of: providing a polymer cement comprising a polymer either melt or dissolved in a solvent to form a polymer cement; dispersing an antiblocking agent within a stream consisting of steam to form atomization steam; atomizing the polymer cement; contacting the atomized polymer cement with the atomization steam; and recovering polymeric particles. Polymeric particles so prepared have an average particle size of between 100 and 1000 microns. In a preferred embodiment the polymers produced, are rubbery polymers which are free flowing.
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 February 11, 1991 and granted May 28, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 11, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 11, 2013.
- 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.