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:
Jun. 22, 1993
Filed:
Nov. 01, 1991
Katsuo Imatani, Ube, JP;
Yuji Matsui, Ube, JP;
Ube Industries, Ltd., Yamaguchi, JP;
Abstract
An abrasive sheet having a high flexibility, mechanical strength and heat resistance, comprises (A) a matrix comprising an aromatic polyimide resin and (B) abrasive grains having an average size of 65-150 .mu.m and evenly dispersed in an amount of 2 to 50% by weight in the matrix, and is produced by forming a thin liquid layer from a dispersion comprising an aromatic polyamic acid solution with a rotation viscosity of 3000 to 6000 poises at 30.degree. C. and the above-mentioned abrasion grains dispersed in the solution, and dry-solidifying the liquid layer of the dispersion while imidizing the aromatic polyamic acid to a corresponding aromatic polyimide, the abrasive sheet having a thickness of 1.1 to 3.0 times the average size of the abrasive grains.