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:
Sep. 08, 2009
Filed:
May. 20, 2004
Douglas W. Luther, Walker, LA (US);
Douglas W. Luther, Walker, LA (US);
Albemarle Corporation, Richmond, VA (US);
Abstract
Despite the frangibility of additive-free granules of brominated anionic styrenic polymer, it has been found possible by use of special mechanical processing to provide pellets of unadulterated brominated anionic styrenic polymer having a bromine content of at least about 50 wt % and in which at least about 70 wt % (preferably at least about 75 wt %) of the pellets are retained on a standard US No. 40 sieve and no more than about 30 wt % (preferably no more than about 25 wt %) are retained on a standard US No. 5 sieve. In preferred embodiments such pelletized anionic styrenic polymer is brominated anionic polystyrene having a bromine content of at least about 67 wt %, e.g., in the range of about 67 to about 71 wt %. Also preferred are pelletized brominated anionic styrenic polymers in which the melt flow index (ASTM D 1238-99) at 220° C., 2.16 kg is at least 4 g/10 min and preferably is at least 5 g/10 min. Another embodiment of this invention is a method of preparing pelletized unadulterated brominated anionic styrenic polymer which method comprises: A) forming strands of molten unadulterated brominated anionic styrenic polymer; B) submitting said strands to cooling and downwardly directed forced air flow on a porous conveyor belt whereby said strands are broken into pellets; and C) causing said pellets to drop into a classifier that removes fines from the pellets.