PROCESS FOR PRODUCING GLASS SUBSTRATE FOR MAGNETIC DISKS

• Main Authors: YOSHIDA KARA, USUI HIROSHI, ISHIDA MIZUHO
• Format: Patent
• Language: English
• Published: 24.09.2009
• Subjects: CHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUSENAMELS; CHEMISTRY; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS; GLASS; GRINDING; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; JOINING GLASS TO GLASS OR OTHER MATERIALS; MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; METALLURGY; MINERAL OR SLAG WOOL; PERFORMING OPERATIONS; PHYSICS; POLISHING; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS,MINERALS OR SLAGS; SURFACE TREATMENT OF GLASS; TRANSPORTING

In the production of a glass substrate for magnetic disks, in a step of polishing a main surface of a circular glass plate, roll-off is reduced without reducing the polishing rate. The process comprises a step of polishing a main surface of a circular glass plate by using an acidic polishing fluid containing colloidal silica or fumed silica, and a water-soluble polymer having at least one member selected from a group consisting of a carboxylic acid group, a carboxylate group, a sulfonic acid group and a sulfonate group, bonded to its main chain, or an acidic polishing fluid containing 100 parts by mass of colloidal silica or fumed silica, and from 0.02 to 0.1 part by mass of a surfactant having a sulfonic acid group.