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:
Apr. 21, 2009
Filed:
Oct. 23, 2007
Phan Linh Tang, West Chester, PA (US);
Phan Linh Tang, West Chester, PA (US);
DuPont Performance Elastomers LLC, Wilmington, DE (US);
Abstract
A novel semi-batch emulsion polymerization process for the production of fluoroelastomers is disclosed wherein a hydrocarbon anionic surfactant is employed as the dispersing agent. The surfactant has the formula R-L-M wherein R is an alkyl group having between 6 and 17 carbon atoms, L is selected from the group consisting of ArSO, SO, SO, POand COOand M is a univalent cation. Preferred surfactants are sulfonates of the formula CH—(CH)—SOM, CH—(CH)—CH—SOM, or CH—(CH)—CH═CHCH—SOM, where n is an integer from 6 to 17, or mixtures thereof, and M is a cation having a valence of 1. Surfactant is not introduced to the reactor until shortly after the polymerization reaction has begun.