Patents Assigned to Polymer Systems AS
  • Patent number: 6559217
    Abstract: The invention provides a process for the preparation of polymer particles having a mode particle size of at least 50 &mgr;m which process comprises (a) obtaining a first particulate polymer seed material having a mode particle diameter of no more than 50 &mgr;m; (b) using said first seed material, performing a suspension polymerization involving the steps: (i) forming an aqueous dispersion comprising a polymer seed material, an organic compound (e.g. a polymerization initiator) which has a molecular weight of less than 5000 Daltons and a water solubility of less than 10−2 g/L at 25° C., a stabilizer and optionally an organic solvent (e.g. acetone or a portion of the monomer mentioned below); (ii) allowing said organic compound to diffuse into the seed material to produce an activated seed material; and (iii) contacting said activated seed material with a monomer (e.g.
    Type: Grant
    Filed: October 9, 2001
    Date of Patent: May 6, 2003
    Assignee: Polymer Systems AS
    Inventors: Rolf Nordal, Svein Tøgersen, Preben Cato Mørk
  • Patent number: 6239224
    Abstract: The invention provides a process for the preparation of a particulate polymer having a mode particle size of at least 200 &mgr;m, the improvement comprising the use of substantially monodisperse polymeric particles as polymerization seeds in a suspension polymerization preparation of said particulate polymer.
    Type: Grant
    Filed: May 5, 1998
    Date of Patent: May 29, 2001
    Assignee: Polymer Systems AS
    Inventors: Preben Cato Mørk, Svein Tøgersen