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:
Feb. 11, 1997
Filed:
Mar. 04, 1992
Binnur Z Gunesin, New York, NY (US);
Patricia J Nelson, Franklin Township, NY (US);
BASF Corporation, Mt. Olive, NJ (US);
Abstract
An anionic dispersion polymerization process is described for preparing linear block copolymers containing an odd number of blocks including blocks of polymerized styrenic compound, e.g., styrene, (A blocks) which are the end or terminal blocks of the polymer and which alternate along the polymer chain with elastomeric blocks of polymerized conjugated diene units (B blocks). The process includes initially contacting the total amount of styrenic compound to be utilized in forming the block copolymer under polymerization conditions with an anionic initiator and dispersant in an inert dispersion medium in which the polymer is insoluble and carrying out the process in stages wherein less than the total amount of styrenic compound is allowed to polymerize, alternating with stages wherein amounts of diene are added and allowed to polymerize completely. The addition of diene interrupts the polymerization of styrenic compound due to the greater tendency of diene to polymerize.