Abstract: A method of texturing a surface of a magnetic hard disk substrate includes the steps of rotating the magnetic hard disk substrate, supplying polishing slurry on the surface of the substrate, and pressing a polishing tape on the substrate surface and running the polishing tape. The polishing slurry includes abrading particles of monocrystalline diamond that are cluster particles with corners having diameters in the range of 1-10 nm, dispersed in a dispersant such as water and a water-based aqueous solution. The cluster particles are tasseled assemblies of crystalline particles with no directionality.

Abstract: A disk processing device holds and rotates a disk with a spindle. Processing tapes are supplied out and wound up by a tape reel unit so as to sandwich and be pressed on both surfaces of the disk through contact rollers. As a crankshaft is rotated, a sliding plate rotates around it and a slidable shaft rotates around a fulcrum part while sliding along the sliding plate such that the contact roller undergoes a reciprocating motion in a radial direction of the disk together with a slider rotatably attached to the slidable shaft.

Abstract: A disk processing device holds and rotates a disk with a spindle. Processing tapes are supplied out and wound up by a tape reel unit so as to sandwich and be pressed on both surfaces of the disk through contact rollers. As a crankshaft is rotated, a sliding plate rotates around it and a slidable shaft rotates around a fulcrum part while sliding along the sliding plate such that the contact roller undergoes a reciprocating motion in a radial direction of the disk together with a slider rotatably attached to the slidable shaft.

Abstract: A method of texturing a surface of a magnetic hard disk substrate includes the steps of rotating the magnetic hard disk substrate, supplying polishing slurry on the surface of the substrate, and pressing a polishing tape on the substrate surface and running the polishing tape. The polishing slurry includes abrading particles of monocrystalline diamond that are cluster particles with corners having diameters in the range of 1-10 nm, dispersed in a dispersant such as water and a water-based aqueous solution. The cluster particles are tasseled assemblies of crystalline particles with no directionality.

Abstract: A polishing cloth to be produced has a surface layer stacked over a base material. The surface layer is made of a foamed layer and a non-foamed layer, the foamed layer including air bubble cells and the non-foamed layer having an externally exposed surface where linear cuts are formed. These linear cuts reach the air bubble cells such that the air bubble cells communicate with the exterior through the linear cuts. These linear cuts are controlled to be 10 ?m or less in length. Such a polishing cloth is produced by applying a foamable coating material such as a foamable resin over a surface of the base material, foaming the foamable coating material to form the surface layer, and forming the linear cuts through the non-foamed layer.

Abstract: Polishing slurry for texturing the surface of a magnetic hard disk substrate has abrading particles with diameters in the range of 1-10 nm dispersed in a dispersant such as water and a water-based aqueous solution. The abrading particles may be monocrystalline diamond particles, polycrystalline diamond particles or cluster particles with monoerystalline and polycrystalline diamond particles.

Abstract: Texturing marks are formed on the surface of a substrate of a magnetic hard disk first by forming approximately concentric circular preliminary marks in a first step and then forming in a second step approximately concentric circular texturing marks on the surface of the substrate based on the preliminary marks formed in the first step. The surface after the texturing marks are formed in the second step has average surface roughness in the range of 1 ? or more and 6 ? or less and a ratio of maximum surface roughness to the average surface roughness in the range of less than 10. A foamed tape and a lubricant not containing any abrading particles are used in the second step.

Abstract: A cleaning sheet has a foamed layer on the surface of a plastic base sheet with the thickness in the range of 25 ?m or more and 125 ?m or less. The foamed layer has average diameter of air bubbles in the range of 1 ?m or more and 50 ?m or less and preferably 30 ?m or less, compressibility in the range of 3% or more and 7% or less, compression recovery ratio in the range of 40% or more and 60% or less, and the Shore D hardness in the range of 20 degrees or more and 30 degrees or less.

Abstract: A polishing cloth to be produced has a surface layer stacked over a base material. The surface layer is made of a foamed layer and a non-foamed layer, the foamed layer including air bubble cells and the non-foamed layer having an externally exposed surface where linear cuts are formed. These linear cuts reach the air bubble cells such that the air bubble cells communicate with the exterior through the linear cuts. These linear cuts are controlled to be 10 ?m or less in length. Such a polishing cloth is produced by applying a foamable coating material such as a foamable resin over a surface of the base material, foaming the foamable coating material to form the surface layer, and forming the linear cuts through the non-foamed layer.

Abstract: A polishing cloth has a surface layer stacked over a base material. The surface layer is made of a foamed layer and a non-foamed layer, the foamed layer including air bubble cells and the non-foamed layer having an externally exposed surface where linear cuts are formed. These linear cuts reach the air bubble cells such that the air bubble cells communicate with the exterior through the linear cuts. These linear cuts are controlled to be 10 ?m or less in length.

Abstract: Texturing line marks are formed clearly and uniformly over a surface of a glass substrate for a magnetic hard disk such that there will be no abnormal protrusions exceeding 100 ? and the line density will be 30 lines/?m or more by rotating the glass substrate, supplying slurry on the surface of the glass substrate and pressing a processing tape on the surface of the glass substrate and running the processing tape. The slurry includes abrading particles of an artificial diamond material produced by a shock method and dispersed in a dispersing medium. The abrading particles include primary particles that are artificial diamond particles with average diameter 1 nm-20 nm and cluster particles with secondary particles that are artificial diamond particles with average diameter 0.05 ?m-0.20 ?m. The dispersing medium of the slurry includes water and an additive that contains higher aliphatic amide and two or more selected from the group consisting of glycol compounds, organic phosphates and surfactants.

Abstract: A magnetic hard disk substrate is produced by rotating an aluminum substrate or a glass substrate, supplying polishing slurry on its surface, pressing a polishing tape on the surface and running it in a direction opposite to the direction of rotation of the substrate. Texturing marks are formed with a line density greater than 70 lines/?m in the radial direction on the surface. The polishing slurry has abrading particles dispersed in a dispersant. The abrading particles may be monocrystalline diamond particles, polycrystalline diamond particles or cluster particles with such monocrystalline and polycrystalline diamond particles with diameters in the range of 1-50 nm. Agglomerated particles of such cluster particles that are agglomerated in the dispersant may also be included as the abrading particles.

Abstract: A magnetic hard disk substrate is produced by rotating an aluminum substrate or a glass substrate, supplying polishing slurry on its surface, pressing a polishing tape on the surface and running it in a direction opposite to the direction of rotation of the substrate. Texturing marks are formed with a line density greater than 70 lines/?m in the radial direction on the surface. The polishing slurry has abrading particles dispersed in a dispersant. The abrading particles may be monocrystalline diamond particles, polycrystalline diamond particles or cluster particles with such monocrystalline and polycrystalline diamond particles with diameters in the range of 1-50 nm. Agglomerated particles of such cluster particles that are agglomerated in the dispersant may also be included as the abrading particles.

Abstract: A foamed polishing sheet for use in a free particle polishing method using abrading particles with average particle diameter less than 0.1 ?m is produced by applying a foaming paint of a foaming resin on a surface of a form-providing film such as a plastic film, foaming the foaming paint by a wet foaming method to form a foamed sheet on the surface of the form-providing film, and peeling off the foamed sheet from the form-providing film so as to form a polishing surface on the foamed sheet having the same shape as the surface of the form-providing film.

Abstract: A magnetic hard disk substrate is produced by rotating an aluminum substrate or a glass substrate, supplying polishing slurry on its surface, pressing a polishing tape on the surface and running it in a direction opposite to the direction of rotation of the substrate. Texturing marks are formed with a line density greater than 70 lines/&mgr;m in the radial direction on the surface. The polishing slurry has abrading particles dispersed in a dispersant. The abrading particles may be monocrystalline diamond particles, polycrystalline diamond particles or cluster particles with such monocrystalline and polycrystalline diamond particles with diameters in the range of 1-50 nm. Agglomerated particles of such cluster particles that are agglomerated in the dispersant may also be included as the abrading particles.

Abstract: A polishing cloth has a surface layer stacked over a base material. The surface layer is made of a foamed layer and a non-foamed layer, the foamed layer including air bubble cells and the non-foamed layer having an externally exposed surface where linear cuts are formed. These linear cuts reach the air bubble cells such that the air bubble cells communicate with the exterior through the linear cuts. These linear cuts are controlled to be 10 &mgr;m or less in length. Such a polishing cloth is produced by applying a foamable coating material such as a foamable resin over a surface of the base material, foaming the foamable coating material to form the surface layer, and forming the linear cuts through the non-foamed layer.

Abstract: Polishing slurry for texturing the surface of a magnetic hard disk substrate has abrading particles with diameters in the range of 1-10 nm dispersed in a dispersant such as water and a water-based aqueous solution. The abrading particles may be monocrystalline diamond particles, polycrystalline diamond particles or cluster particles with monocrystalline and polycrystalline diamond particles. A method of texturing a surface of a magnetic hard disk substrate includes the steps of rotating the magnetic hard disk substrate, supplying polishing slurry of this invention on the surface of the substrate, and pressing a polishing tape on the substrate surface and running the polishing tape.

Abstract: A polishing tape makes use of a foamed material such as polyurethane foam attached to a plastic backing material. The foamed material is elastic and some of its gas holes formed inside but near one of its surfaces are exposed externally. Because of its elastic nature, it can be deformed even if there are abnormally large abrading particles contained in a liquid slurry and such abrading particles do not become embedded in the target surface being textured. These externally exposed gas holes can also serve to absorb the debris generated by the texturing and to protect the target surface from being scratched thereby. Such a tape is used for a texturing process while dropping a liquid slurry containing abrading particles and rotating the disk substrate and pressing the tape against the target surface.

Abstract: An adhesive tape of the double-side type for attaching a polishing pad to a polisher and for backing a polishing pad and a polishing tape has a base sheet with both its front and back surfaces coated with an adhesive agent and a peeling sheet of a resin material is adhesively attached onto at least one of the surfaces of the base sheet. The peeling sheet may be made of polyethylene terephthalate or polypropylene and is treated such that it can be peeled easily.

Abstract: Slurries to be supplied to the surface of a rotating glass substrate for texturing the surface to create streaks contain aggregates having diameters not larger than 0.51 &mgr;m of polycrystalline diamond particles that are dispersed in water or a water-based aqueous solution that is free of any substance having an etching effect on a glass material. A glass substrate is textured by supplying such a slurry material on its surface as the substrate is rotated and a polishing tape is pressed and run against the substrate surface.