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Expired Canadian patentCanada

Precoagulation process for incorporating organic fibrous fillers in sbr

CA 2028964 C · Owner: E.I. Du Pont De Nemours And Company · Inventors: Kafka, Fred Yerkes

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

Incorporation of fibrous filler into a styrene-butadiene rubber (SBR) by mixing a fibrous filler, SBR latex and a coagulant, feeding the resulting coagulated fiber-filled SBR latex to a dewatering extruder and through a flow restriction that applies back pressure sufficient that water present in the SBR is forced out of a vent upstream from the flow restriction and discharging the fiber-filled SBR from the extruder.

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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 31, 1990 and granted October 24, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 31, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 31, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledOctober 31, 1990
GrantedOctober 24, 2000
Term endedOctober 31, 2010
Patent numberCA 2028964 C
Classification (IPC)B29B7/90 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedOct 31, 1990Patent grantedOct 24, 2000Term endedOct 31, 2010

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.