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. 26, 1993
Filed:
May. 08, 1991
Applicant:
Inventors:
William J Trepka, Bartlesville, OK (US);
George A Moczygemba, Bartlesville, OK (US);
Ralph C Farrar, Jr, Bartlesville, OK (US);
Assignee:
Phillips Petroleum Company, Bartlesville, OK (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C08F / ;
U.S. Cl.
CPC ...
525314 ; 525250 ; 525271 ;
Abstract
A method for preparing tapered block copolymers in a polymerization process by sequentially charging: (1) an initiator and monovinylaromatic monomers in the presence of a randomizer; (2) an initiator and a mixture of monovinylaromatic and conjugated diene monomers; (3) an initiator and a mixture of monovinylaromatic and conjugated diene monomers; and (4) a coupling agent to produce a polymodal tapered block copolymer. The copolymers are particularly useful for packaging applications which require good environmental stress crack resistance.