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:
Nov. 25, 2003
Filed:
Jun. 26, 2001
Applicant:
Inventor:
Yukio Sato, Kanagawa, JP;
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B29C 4/402 ;
U.S. Cl.
CPC ...
B29C 4/402 ;
Abstract
The present invention provides a wiping material for a vacuum chamber having sufficient sludge wiping properties and water retention attained by easy control over cell diameter and use of a polyurethane foam which has been foamed free from a silicone-based surface active agent and a process for the production thereof. A wiping material made of a polyurethane foam for a vacuum chamber for use in the preparation of a silicon wafer is described, wherein the polyurethane foam is free of silicone and has an open-cell structure comprising cells the diameter of which are controlled to fall within the range of from 500 &mgr;m to 3,000 &mgr;m.