Patent Number: 6,309,434

Title: Polishing composition and method for producing a memory hard disks

Abstract: A polishing composition for a magnetic disk substrate to be used for a memory hard disk, which comprises: (a) colloidal silica as an abrasive in an amount within a range of from 0.1 to 35 wt % based on the total weight of the composition; (b) iron nitrate as a polishing accelerator in an amount within a range of from 0.04 to 2.2 wt % based on the total weight of the composition; (c) citric acid as a stabilizer in an amount within a range of from 0.4 to 22 wt % based on the total weight of the composition; (d) hydrogen peroxide as a polishing acceleration assistant in an amount within a range of from 0.155 to 9.3 wt % based on the total weight of the composition; and (e) water.

Inventors: Ohashi; Keigo (Aichi, JP)

Assignee: Fujimi Incorporated

International Classification: C09K 3/14 (20060101); C09G 1/00 (20060101); C09G 1/02 (20060101); G11B 5/84 (20060101); C09G 001/02 (); C09G 001/04 (); C09K 003/14 ()

Expiration Date: 10/30/2018