Abstract: A polishing composition of abrasive grains, a phosphorus-containing inorganic acid or salt thereof and another inorganic acid or salt thereof contained in an aqueous medium is used for the polishing of magnetic disk substrates or the like.

Abstract: An object of the present invention is to provide a composition for polishing a magnetic disk substrate that is used as a storage device for a computer or the like, and is capable of producing a magnetic disk substrate polished with high precision suitable for use in combination with a magnetic head that floats at a low level. Another object of the present invention is to provide a method of producing the composition for polishing the magnetic disk substrate. A polishing composition includes alkali metal ions, abrasive grains, a carboxylic acid, an oxidizing agent, and an anti-gelling agent contained in an aqueous medium. In a method of the present invention for preparing a polishing composition, a pH value of an aqueous medium, in which abrasive grains, a carboxylic acid, an oxidizing agent, and an anti-gelling agent are contained, is adjusted to a range of about 1 to about 5 by the addition of alkali metal hydroxide to the aqueous medium.

Abstract: The present invention provides an abrasive composition for polishing magnetic recording disk substrates that results in a low surface roughness of the magnetic recording disk, allows the attaining of high-density recording without the occurrence of protrusions or polishing scratches, and enables polishing to be performed at an economical speed. The present invention discloses an abrasive composition for polishing magnetic recording disk substrates comprising water, silicon dioxide, antigelling agent, aluminum nitrate and hydrogen peroxide.

Abstract: An abrasive composition for substrates for magnetic recording disks and a process for producing a substrate for a magnetic recording disk are provided, which enable lowering of surface roughness of a substrate for a magnetic recording disk; form no nodules, polishing scratches, and minute defects such as micropits; and enable polishing at economical speeds. The abrasive composition comprises at least water, titanium oxide fine particles and an abrasion promoter, wherein 90-100% of the titanium oxide is constituted by a single crystal structure.

Abstract: The present invention provides an abrasive composition for polishing magnetic recording disk substrates that results in a low surface roughness of the magnetic recording disk, allows the attaining of high-density recording without the occurrence of protrusions or polishing scratches, and enables polishing to be performed at an economical speed. The present invention discloses an abrasive composition for polishing magnetic recording disk substrates comprising water, silicon dioxide, antigelling agent, aluminum nitrate and hydrogen peroxide.

Abstract: An object of the present invention is to provide a composition for polishing a magnetic disk substrate that is used as a storage device for a computer or the like, and is capable of producing a magnetic disk substrate polished with high precision suitable for use in combination with a magnetic head that floats at a low level. Another object of the present invention is to provide a method of producing the composition for polishing the magnetic disk substrate. A polishing composition includes alkali metal ions, abrasive grains, a carboxylic acid, an oxidizing agent, and an anti-gelling agent contained in an aqueous medium. In a method of the present invention for preparing a polishing composition, a pH value of an aqueous medium, in which abrasive grains, a carboxylic acid, an oxidizing agent, and an anti-gelling agent are contained, is adjusted to a range of about 1 to about 5 by the addition of alkali metal hydroxide to the aqueous medium.

Abstract: A composition for polishing magnetic disk substrates having an Ni—P plating, comprising water, silicon oxide, a metal coordination compound, and an oxidizing agent. The composition may further contain a pH adjusting agent.

Abstract: An abrasive composition for polishing a substrate for a magnetic recording disc is described, which comprises finely divided titanium oxide particles, an abrasion promoter, an optional water-soluble oxidizing agent, and water. This abrasive composition is used for polishing a substrate for a magnetic recording disc by a process wherein the substrate is polished with a pad while the abrasive composition is supplied between the substrate and the pad, and at least one of the pad and the substrate is rotated. The contents of the finely divided titanium oxide particles, the abrasion promoter and the optional water-soluble oxidizing agent are 2-20 wt. %, 1-20 wt. % and up to 10 wt. %, respectively, based on the weight of the abrasive composition as used for polishing the substrate.