Modified acrylic urethane prepolymer concentrate and polyester resins containing same
CA 2251556 C · Owner: Hehr International Inc. · Inventors: Smith, Stuart B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A modified acrylic urethane prepolymer composition and an unsaturated polyester resin composition to which the prepolymer has been added. The prepolymer composition includes an acrylic urethane prepolymer prepared by the reaction of diisocyanate, like MDI, with a hydroxyl-containing acrylate monomer, such as a pentaerythritol triacrylate which prepolymer composition , may contain a styrene monomer and an inhibitor such as benzoquinone, to , retard the reaction of the prepolymer and styrene monomer prior to the addition of the prepolymer composition into the polyester resin composition. The employment of the modified urethane prepolymer composition provides for the reduction in the …
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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 April 10, 1997 and granted July 8, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 10, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 10, 2019.
- 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
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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.