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. 13, 1998
Filed:
Apr. 02, 1996
Stephen D Williams, Newark, DE (US);
Hee Ju Yoo, Wilmington, DE (US);
Miriam R Drickman, Boulder, CO (US);
Montell North America Inc., Wilmington, DE (US);
Abstract
A propylene homopolymer having a stick-point of 30 cm or less during melt spinning, an oligomer content of less than 1500 ppm without postpolymerization treatment to remove oligomers, and a melt flow rate greater than 300 dg/min is prepared by radiation visbreaking in a multistage fluidized bed reactor. The polymer is subjected to irradiation in the substantial absence of oxygen, followed by a multistage treatment in the presence of a controlled amount of oxygen. The radiation visbreaking process can also be applied to other propylene polymer materials. The propylene polymer materials produced by this radiation visbreaking process can be used, for example, for extrusion coating, film production, and injection molding.