Alkadiene/vinylaromatic copolymers containing side groups, and their use
CA 2063674 A1 · Owner: Bronstert, Klaus · Inventors: Bender, Dietmar; Bronstert, Klaus; Mach, Helmut
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
O.Z. 0050/42318, Abstract of the Disclosure: The novel alkadiene/vinylaromatic copolymers which contain side groups and have a random, block-like or star-like structure and whose polymerized alkadiene comonomer units are partially or completely selectively hydrogenated, and which contain one or more side groups having one or more radicals capable of (4+2) cycloaddition (Diels-Alder reaction) with dienophiles are suitable as such as viscosity index (VI) improvers or can be used for the preparation of dispersant VI improvers. For this purpose they are, reacted with one or more dienophiles which are capable of a Diels-Alder (4+2) cycloaddition reaction and preferably contain strongly polar …
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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 March 20, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 20, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 20, 2014.
- 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.