Foamable pvc resin formulation, process for foaming, and product thereof
CA 1100698 A · Owner: Stauffer Chemical Company · Inventors: Goswami, Jagadish C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure, A foamable polyvinyl chloride (PVC) resin formulation containing (1) a copolymer formed by emulsion polymerizing from about 70% to about 90% vinyl chloride, from about 5% to about 15% vinyl acetate and from about 5% to about 15% of a bis (hydrocarbyl)vinylphosphonate; (2) a polyester or epoxy plasticizer (or mixture thereof) and (3) 4,4'-oxybis (benzene sulfonyl hydrazide) is foamed to form a product having a smooth unblistered surface, good cell quality and medium density. The foaming can take place at a temperature of from about 320°F. (160°C.) to about 400°F. (204°C.) for a period of time of from about 6 to about 20 minutes.
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
- Granted May 5, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 5, 1998.
- 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.