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:
Jul. 25, 2000
Filed:
Apr. 09, 1997
Mehmet Demirors, Terneuzen, NL;
Jozef Julius Sleeckx, Sint-Martens-Latem, BE;
Peter Hendrikus Vollenberg, Gent, BE;
Chau V Vo, Souffelweyersheim, FR;
Gary C Welsh, Midland, MI (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
Monovinyl aromatic polymer compositions with high melt strength, good flow and good heat properties which are suitable for fast injection molding, blow molding and thermoforming applications, comprising non-linear monovinyl aromatic polymers and copolymers having comb-type structures with 3 branches, star type structures with 4 to 6 branches, and/or dendritic structures in which the branches themselves have attached branched units. These compositions possess inherent melt strength and can be blow molded or thermoformed without sagging or molded into articles in shorter cycle times using less material than linear monovinyl aromatic polymers and copolymers with the same flow and heat distortion temperatures. Also disclosed is a process for making high molecular weight branched monovinyl aromatic polymers, for example, Mw between 75,000 and 500,000, at high rates, comprising polymerizing pure styrene monomer or styrene monomer and polymerizable comonomer via a continuous free radial polymerization process using a peroxide initiator, for example, n-butyl tert-butyl peroxy fumarate, selected from a new class of vinyl peroxide initiators that contain both a copolymerizable double bond and an organic peroxide moiety.