Block copolymers of monovinylarenes and conjugated dienes and preparation thereof
CA 2117708 C · Owner: Moczygemba, George A. · Inventors: Stacy, Nathan E.; Selman, Charles M.; Trepka, William J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for preparing resinous polymodal monovinylarene-conjugated diene block copolymers and polymers produced thereby are provided. The method comprises sequentially contacting under polymerization conditions:, (a) a monovinylarene monomer and initiator; (b) initiator and a monovinylarene monomer; (c) a sequence of at least two charges selected from the group consisting of (i) initiator and a monovinylarene monomer, (ii) a mixture of monovinylarene monomer and conjugated diene monomer, (iii) a conjugated diene monomer, (iv) a monovinylarene monomer; (d) a coupling agent;, wherein the sequence of at least two charges in step (c) can be made in any order. In a preferred embodiment at least …
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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 September 20, 1994 and granted October 22, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 20, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 20, 2016.
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