Urethane polymers for printing plate compositions
CA 2040097 A1 · Owner: Yokoyama, Wako · Inventors: Yokoyama, Wako
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A urethane polymer having free carboxyl groups on the backbone of the polymer and terminal methacrylate groups is prepared by (1) reacting a mixture of at least two aliphatic diols and an aliphatic dihydroxy mono- or dicarboxylic acid with an excess of an aliphatic, cycloaliphatic or aromatic diisocyanate in the presence of a catalyst to produce an isocyanate-terminated urethane polymer and (2) reacting the terminal isocyanate groups of the product of step (1) with an aliphatic monohydroxy methacrylate. The polymer can be used in photopolymerizable compositions for making tack-free flexographic printing plates.
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 April 9, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 9, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 9, 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.