The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 25, 2008
Filed:
Aug. 20, 2007
Karel Cornelis Bleijenberg, Hilversum, NL;
Michel F. J. Berghmans, Calgary, CA;
Hugo A. A. Berghmans, Leuven, BE;
Karel Cornelis Bleijenberg, Hilversum, NL;
Michel F. J. Berghmans, Calgary, CA;
Hugo A. A. Berghmans, Leuven, BE;
NOVA Chemicals Inc., Moon Township, PA (US);
Abstract
Process for preparing polymer, e.g. polystyrene, particles that may not or may contain a water-retaining agent and that require only a one-step process for incorporating the water-retaining agent. The polymer particles may be prepared via an extrusion process, or a bulk polymerization process wherein a water-retaining agent is blended into the polymer melt. Water is incorporated into the particles by soaking them in hot or cold water or treating the particles with steam for a predetermined time depending on the desired water content in the particles. The water-retaining agent may be starch, zeolite, silica dioxide or poly (N-isopropyl acrylamide) ranging from 0.1% to 10.0% by weight. The particles can be expanded via appropriate means to form pre-expanded or expanded particles in a conventional manner.