IP Library Granted Patent US 7,700,205
Granted Patent B2
US 7,700,205 · App. 11/660,667 · Granted Apr 20, 2010

Process for manufacturing glass substrate for magnetic recording medium, glass substrate for magnetic recording medium obtained by the process, and magnetic recording medium obtained using the substrate

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Quick Facts
Patent No.
US 7,700,205
App. No.
11/660,667
Granted
Apr 20, 2010
Kind
B2
Abstract

A process for manufacturing a glass substrate for a magnetic recording medium comprising polishing a crystallized glass substrate using abrasive grains, and then washing the substrate using an aqueous organic carboxylic acid solution; a glass substrate for a magnetic recording medium which is manufactured by the process; and a magnetic recording medium obtained using the substrate. A glass substrate for a magnetic recording medium is manufactured, whereby the surface roughness is low and the surface defects are minimal for washing after polishing of a crystallized glass substrate, and wherein the Read-Write performance are not impaired when a recording layer including a magnetic film is formed on the magnetic recording medium substrate for manufacturing a magnetic recording medium.

Claims (3)

1. A process for manufacturing a glass substrate for a magnetic recording medium, comprising polishing a crystallized glass substrate using abrasive grains, and then washing the substrate with an aqueous solution comprising oxalic acid and no strong acid, and wherein washing of the substrate after the polishing with the abrasive grains is not carried out with a strong acid or a strong base.

2. A process for manufacturing a glass substrate for a magnetic recording medium according to claim 1 , wherein the concentration of the aqueous organic carboxylic acid solution is 0.1-10% by mass.

3. A process for manufacturing a glass substrate for a magnetic recording medium according to claim 1 , wherein the washing is carried out at a temperature of 10-80° C.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 15, 2024
From: RESONAC CORPORATION
To: RESONAC HARD DISK CORPORATION
Reel/Frame 069167/0673 →
CHANGE OF ADDRESS Recorded Feb 14, 2024
From: RESONAC CORPORATION
To: RESONAC CORPORATION
Reel/Frame 066599/0037 →
CHANGE OF NAME Recorded Jun 23, 2023
From: SHOWA DENKO K.K.
To: RESONAC CORPORATION
Reel/Frame 064082/0513 →