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:
Oct. 21, 1986
Filed:
Aug. 27, 1984
Josef K Rigler, Recklinghausen, DE;
Horst Leithauser, Marl, DE;
Chemische Werke Huls Aktiengesellschaft, Marl, DE;
Abstract
A process for controlling bead size in the production of expandable styrene polymers by suspension polymerization is carried out by adding protective colloids to the aqueous phase before polymerization begins, such protective colloids being used which are homogeneously soluble in water over the entire temperature range from 25.degree. to 125.degree. C. and in which the concentration range being employed shall not lower the boundary surface tension water/styrene below 18 N/mm.sup.2. Lastly, the protective colloids are selected according to their molecular weight and the weight ratio of aqueous to organic phase lies in the range of 0.9:1 to 1:1.25, preferably in the range of 1:1. A grain spectrum is maintained predominantly greater than 0.41 to less than 2.5 mm by varying the molecular weights of the protective colloids.