Method for the production of glass substrates for magnetic recording mediums

Abstract

A method for the production of a glass substrate for magnetic recording mediums comprises disk-processing, grinding, polishing and cleaning steps and the method is characterized in that the grinding step is carried out using a cooling liquid and a both side-grinding device for grinding a glass substrate for magnetic recording mediums, in which thin plate-like nonferrous metal-bonded grinding wheels, resin-bonded grinding wheels or vitrified bonded grinding wheels, containing abrasive grains are adhered to the surfaces of the upper and lower surface tables of the device. The method for the production of a glass substrate for magnetic recording mediums permits the easy and efficient production of a glass substrate for magnetic recording mediums, the method does not require the use of any multistage cleaning stage under the application of ultrasonics and any acid-cleaning stage and it can thus eliminate the possibility of any contamination.

What is claimed is:  
     
         1 . A method for the production of a glass substrate for magnetic recording mediums, which comprises disk-processing, grinding, polishing and cleaning steps, the method being characterized in that the grinding step is carried out using a cooling liquid and a both side-grinding device for grinding a glass substrate for magnetic recording mediums, in which thin plate-like nonferrous metal-bonded grinding wheels, resin-bonded grinding wheels or vitrified bonded grinding wheels, containing abrasive grains are adhered to the surfaces of the upper and lower surface tables of the device.  
     
     
         2 . The method for the production of a glass substrate for magnetic recording mediums as set forth in    claim 1   , wherein the abrasive grains are diamond, cubic boron nitride, boron carbide, silicon carbide, zirconia or alumina grains.  
     
     
         3 . The method for the production of a glass substrate for magnetic recording mediums as set forth in    claim 2   , wherein the abrasive grains are diamond grains.  
     
     
         4 . The method for the production of a glass substrate for magnetic recording mediums as set forth in    claim 1   , wherein solid contents present in the cooling liquid used in the grinding step are removed and then recycled to the device.  
     
     
         5 . The method for the production of a glass substrate for magnetic recording mediums as set forth in    claim 2   , wherein solid contents present in the cooling liquid used in the grinding step are removed and then recycled to the device.  
     
     
         6 . The method for the production of a glass substrate for magnetic recording mediums as set forth in    claim 3   , wherein solid contents present in the cooling liquid used in the grinding step are removed and then recycled to the device.  
     
     
         7 . The method for the production of a glass substrate for magnetic recording mediums as set forth in    claim 4   , wherein the solid contents present in the cooling liquid are removed by filtration through diatomaceous earth as a filtering medium.  
     
     
         8 . The method for the production of a glass substrate for magnetic recording mediums as set forth in    claim 5   , wherein the solid contents present in the cooling liquid are removed by filtration through diatomaceous earth as a filtering medium.  
     
     
         9 . The method for the production of a glass substrate for magnetic recording mediums as set forth in    claim 6   , wherein the solid contents present in the cooling liquid are removed by filtration through diatomaceous earth as a filtering medium.