Multi-stage irradiation process for production of acrylic based compositions and compositions made thereby
CA 2105077 C · Owner: Minnesota Mining And Manufacturing Company · Inventors: Ziegler, Louis A.; Edberg, Mark S.; Mehner, Robert C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed is a novel, multi-stage irradiation process for the production of acrylic-based compositions such as adhesives or pressure-sensitive adhesive tapes. The first irradiation step or stage employs electromagnetic radiation at a relatively low average intensity (i.e. 0.1 to 20 mW/cm2) to effect a relatively low extent of monomer conversion, and the subsequent step employs electromagnetic radiation at a relatively higher average intensity (i.e. greater than 20 mW/cm2) to complete the photopolymerization. Also disclosed are acrylic-based psa tape materials made by the novel process.
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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 February 28, 1992 and granted July 29, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 28, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 28, 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.