Abstract: A method for manufacturing a glass plate including a polishing step of polishing a curved surface of the glass plate using a polisher; wherein the polisher is a rotating brush including a rotating core and brush bristles provided on an external surface of the rotating core, an average diameter of the brush bristle being not more than 300 ?m, and wherein in the polishing step, a position of the rotating brush relative to the glass plate is reciprocated along an axial direction of the rotating brush at a reciprocating speed of not less than 1 mm/sec and a reciprocating amplitude of not less than 0.5 mm.

Abstract: A glass member includes a glass plate, on a first surface of which a functional layer is formed. A Martens hardness measured from a side of the functional layer of the glass member is 1100 N/mm2 or more. The functional layer includes silica. A cut level difference R?c obtained from a roughness curve for a surface of the functional layer is 2% or more. The cut level difference R?c is obtained by subtracting a load length ratio for a cut level of 10%, Rmr(10), from the load length ratio for the cut level of 50%, Rmr(50). The load length ratio for the cut level c is obtained by formula Rmr ? ( c ) = 1 L ? ? i = 1 n ? ? M ? ( c ) i × 100 where M(c)i is a cut length of an i-th cut portion. By cutting the roughness curve at the cut level c within a region having a length L, n cut portions are obtained.

Abstract: Spots generated on a glass substrate after a polishing step are reduced. The present invention relates to a method for polishing a glass substrate including injecting a silica abrasive and a high-boiling solvent in a final glass substrate polishing step. The high-boiling solvent is preferably a solvent having a molecular weight of 300 or lower and a boiling point of 150° C. or higher. As Examples of the high-boiling solvent having a molecular weight of 300 or lower and a boiling point of 150° C. or higher includes ethylene glycol, propylene glycol and glycerine.

Abstract: A method for producing a glass substrate for a magnetic disk by polishing a circular glass plate, which comprises a step of polishing the principal plane of the circular glass plate by using a slurry containing a CeO2 crystal powder, the CeO2 crystal powder being obtained in such a manner that a melt containing CeO2 is quenched to obtain an amorphous material, and the amorphous material is subjected to heat treatment to obtain a CeO2 crystals-precipitated amorphous material, which is subjected to acid treatment to separate and extract the CeO2 crystal powder from the CeO2 crystals-precipitated amorphous material.

Abstract: The present invention relates to a method of glass surface fine processing for forming a convex portion on a surface of a glass containing alkali-metal oxides, the method including: a step of coating a surface of a first region adjacent to a surface of a second region which is to be a convex portion, with a protective layer; a step of removing alkali ions from the surface of the second region; a step of removing the protective layer from the surface of the first region; and a step of polishing the surface of the second region from which the alkali ions have been removed and the surface of the first region from which the protective layer has been removed.

Abstract: Spots generated on a glass substrate after a polishing step are reduced. The present invention relates to a method for polishing a glass substrate including injecting a silica abrasive and a high-boiling solvent in a final glass substrate polishing step. The high-boiling solvent is preferably a solvent having a molecular weight of 300 or lower and a boiling point of 150° C. or higher. As Examples of the high-boiling solvent having a molecular weight of 300 or lower and a boiling point of 150° C. or higher includes ethylene glycol, propylene glycol and glycerine.

Abstract: A method for producing a glass substrate for a magnetic disk by polishing a circular glass plate, which comprises a step of polishing the principal plane of the circular glass plate by using a slurry containing a CeO2 crystal powder, the CeO2 crystal powder being obtained in such a manner that a melt containing CeO2 is quenched to obtain an amorphous material, and the amorphous material is subjected to heat treatment to obtain a CeO2 crystals-precipitated amorphous material, which is subjected to acid treatment to separate and extract the CeO2 crystal powder from the CeO2 crystals-precipitated amorphous material.