Abstract: To provide a composition capable of minimizing the average surface roughness (Ra) after texturing of the ground layer of an aluminum magnetic disc or the surface of a glass magnetic disc, forming fine texturing streaks, removing “polishing marks” or “polishing scratches” ascribable to the substrate polishing step and which are present on the ground layer or on the surface, and ensuring a high processing rate. A composition for a texturing process, which is used for texturing a ground layer of an aluminum magnetic disc or a surface of a glass magnetic disc, the composition comprising (A) nano-diamond particles having a specific surface area of 150 m2/g or more, (B) a fatty acid having from 10 to 22 carbon atoms or a fatty acid salt, and (C) an organic amine compound.

Abstract: To provide a polishing composition which enables maintenance of excellent properties and high quality of the surface of a hard disk without lowering polishing rate during polishing of the surface, and which can provide a polished surface in which the amount of dub-off is considerably reduced as compared with that of a conventional level, a polishing composition containing water, a polishing material (particularly alumina), a polishing accelerator, and at least one of hydroxypropyl cellulose and hydroxyalkyl alkyl cellulose is provided.

Abstract: To provide a polishing composition which enables maintenance of excellent properties and high quality of the surface of a hard disk without lowering polishing rate during polishing of the surface, and which can provide a polished surface in which the amount of dub-off is considerably reduced as compared with that of a conventional level, a polishing composition containing water, a polishing material (particularly alumina), a polishing accelerator, and at least one of hydroxypropyl cellulose and hydroxyalkyl alkyl cellulose is provided.