Method of manufacturing monodisperse poly(meth) acrylate particles
CA 2129481 C · Owner: Wopker, Wilhelm · Inventors: Wopker, Wilhelm; Parusel, Markus; Siol, Werner
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a method of manufacturing monodisperse poly(meth)acrylates by the method of precipitation polymerization, comprising polymerizing i) a monomer mixture comprising at least 60 wt.% of monomer of formula I, (see fig.I), where R represents hydrogen or methyl; and R1 represents a C1-8 alkyl group, a C6-24 aryl group a, C1-8 alkyl substituted aryl group or an aralkyl group; ii) 0.1-10 wt.% based on the weight of the monomer mixture of a block copolymer having polystyrene components; and, iii) 0.02-2 wt.% based on the weight of the monomer mixture of a percarbonic acid ester;, in a halogen free solvent comprising 70 to 100 wt.% of cyclohexane.
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 August 4, 1994 and granted August 18, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 4, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 4, 2016.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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.