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. 18, 2000
Filed:
Jul. 31, 1997
JSP Corporation, , JP;
Abstract
A foamed, non-crosslinked resin particle having a bulk density of not greater than 0.045 g/cm.sup.3 and an average cell diameter of at least 200 .mu.m. The non-crosslinked resin includes a polypropylene resin to which a vinyl comonomer is graft-polymerized in such an amount that the weight ratio of the polypropylene resin to the grafted polymer of the vinyl comonomer is in the range of 97:3 to 65:35. The foamed resin particles are produced by grafting a vinyl comonomer to polypropylene resin particles at a temperature of less than 90.degree. C. in the presence of a specific radical polymerization initiator to obtain modified polypropylene resin particles and, then, expanding the modified polypropylene resin particles. The initiator used requires a temperature of not higher than 70.degree. C. for obtaining a half life of 10 hours.