摘要:
A method for producing a magnetic disk having a surface roughness in the entire portion of its main surface in which the peak height of the surface roughness in a data zone of the magnetic disk is lower than the peak height of the surface roughness in a CSS zone of the magnetic disk, wherein forming a magnetic disk substrate having the main surface in which a surface roughness having a substantially uniform peak height is formed in the substantially entire portion of the main surface; conducting varnishing only to the data zone in the main surface of the substrate having the surface roughness to lower the peak height of the surface roughness of the data zone; and forming a ferromagnetic layer, a protective layer and a lubricant layer sequentially on a region of the main surface of the substrate, which includes the data zone and the CSS zone.
摘要:
The present invention relates to a glass substrate for a magnetic recording medium, which is a disk-shaped glass substrate for a magnetic recording medium having a circular hole at the center thereof, in which the glass substrate for a magnetic recording medium has an inner peripheral side surface, an outer peripheral side surface and both main surfaces, and the both main surfaces have parallelism of 3.2 μm or less in at least a recording and reproducing region thereof.
摘要:
The present invention relates to a method for manufacturing a glass substrate for information recording medium, the method including: a lapping step of lapping a circular glass plate made of an alkali aluminosilicate glass; and a subsequent cerium oxide polishing step of polishing the circular glass plate with a slurry containing a cerium oxide abrasive, in which a difference (SiO2−Al2O3) obtained by subtracting an Al2O3 content from an SiO2 content in the alkali aluminosilicate glass is 62% by mole or less; and in which the method further includes: subsequently to the cerium oxide polishing step, a cleaning step of cleaning the circular glass plate with a cleaning liquid having a sulfuric acid concentration of 20% by mass or more and 80% by mass or less and a hydrogen peroxide concentration of 1% by mass or more and 10% by mass or less at a liquid temperature of 50° C. or higher and 100° C. or lower, and after the cleaning step, a finish polishing step of polishing a main surface of the circular glass plate with a slurry containing a colloidal silica abrasive.
摘要翻译:本发明涉及一种用于信息记录介质的玻璃基板的制造方法,该方法包括:研磨由铝硅酸铝玻璃制成的圆形玻璃板的研磨步骤; 以及后续的氧化铈抛光步骤,用含有氧化铈磨料的浆料研磨圆形玻璃板,其中通过从碱性铝硅酸盐玻璃中的SiO 2含量减去Al 2 O 3含量而得到的差异(SiO 2 -Al 2 O 3)为62% 摩尔或更少; 该方法还包括:随后的氧化铈抛光步骤,用硫酸浓度为20质量%以上且80质量%以下的清洗液清洗圆形玻璃板的清洗工序, 过氧化氢浓度在50℃以上且100℃以下的液温下为1质量%以上且10质量%以下,在清洗工序后,对主体进行研磨的精抛光工序 具有含有胶体二氧化硅研磨剂的浆料的圆形玻璃板的表面。
摘要:
The present invention relates to a method for manufacturing a disk-shaped glass substrate for a magnetic recording medium, having a circular hole at the center thereof, the method including: a shape-forming step of performing shape forming to a glass substrate having a sheet shape; a polishing step of polishing a main surface of the glass substrate; and a cleaning step of cleaning the glass substrate, in which the polishing step includes a finish polishing step of simultaneously polishing both main surfaces of the glass substrate using a polishing slurry containing abrasives having an average particle diameter of 100 nm or less; and the glass substrate polished in the finish polishing step has a thickness deviation among glass substrates polished in the same lot of 1.5 μm or less.
摘要:
The present invention relates to a method for manufacturing a glass substrate for information recording medium, the method including: a lapping step of lapping a circular glass plate made of an alkali aluminosilicate glass; and a subsequent cerium oxide polishing step of polishing the circular glass plate with a slurry containing a cerium oxide abrasive, in which a difference (SiO2−Al2O3) obtained by subtracting an Al2O3 content from an SiO2 content in the alkali aluminosilicate glass is 62% by mole or less; and in which the method further includes: subsequently to the cerium oxide polishing step, a cleaning step of cleaning the circular glass plate with a cleaning liquid having a sulfuric acid concentration of 20% by mass or more and 80% by mass or less and a hydrogen peroxide concentration of 1% by mass or more and 10% by mass or less at a liquid temperature of 50° C. or higher and 100° C. or lower, and after the cleaning step, a finish polishing step of polishing a main surface of the circular glass plate with a slurry containing a colloidal silica abrasive.
摘要翻译:本发明涉及一种用于信息记录介质的玻璃基板的制造方法,该方法包括:研磨由铝硅酸铝玻璃制成的圆形玻璃板的研磨步骤; 以及后续的氧化铈抛光步骤,用含有氧化铈磨料的浆料研磨圆形玻璃板,其中通过从碱性铝硅酸盐玻璃中的SiO 2含量减去Al 2 O 3含量而得到的差异(SiO 2 -Al 2 O 3)为62% 摩尔或更少; 该方法还包括:随后的氧化铈抛光步骤,用硫酸浓度为20质量%以上且80质量%以下的清洗液清洗圆形玻璃板的清洗工序, 过氧化氢浓度在50℃以上且100℃以下的液温下为1质量%以上且10质量%以下,在清洗工序后,对主体进行研磨的精抛光工序 具有含有胶体二氧化硅研磨剂的浆料的圆形玻璃板的表面。