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:
Dec. 27, 2005
Filed:
Dec. 05, 2001
Shunji Kaneda, Okayama, JP;
Chihiro Okamoto, Osaka, JP;
Shunji Kaneda, Okayama, JP;
Chihiro Okamoto, Osaka, JP;
Kuraray Co., Ltd., Kurashiki, JP;
Abstract
The present invention aims to provide a polyurethane foam, suitably usable as a polishing pad, having a uniform foam structure, which can achieve the improvements in the flatness of the surface of polished materials and in the planarization efficiency, and can extend the polishing pad life longer than that of the conventional polyurethane foams. This aim can be achieved by providing a polyurethane foam having a density of 0.5 to 1.0 g/cm, a cell size of 5 to 200 μm and a hardness [JIS-C hardness] of not less than 90, comprising a thermoplastic polyurethane which is obtained by a reaction of a high polymer polyol, an organic diisocyanate and a chain extender, contains not less than 6% by weight of a nitrogen atom derived from the isocyanate group, and has a storage elastic modulus measured at 50° C. [E'] of not less than 5×10dyn/cm.