Abstract: An object of the present invention is to provide a plating method on a glass base plate. The method allows forming a plating film on a base plate composed of a glass material with excellent adhesivity and homogeneity by means of an electroless plating method even to a thickness of 1 ?m or more. Before forming a plating film by a step of electroless plating S6, a surface treatment process is conducted on a surface of the base plate composed of a glass material. The surface treatment process comprises at least a step of glass activation treatment S2 to increase quantity of silanol groups on the surface of the base plate at least by a factor of two using an aqueous solution of diluted acid, a step of silane coupling agent treatment S3, a step of palladium catalyst treatment S4, and a step of palladium bonding treatment S5.

Abstract: A disk substrate for a perpendicular magnetic recording medium is, disclosed. The substrate exhibits sufficient productivity, serves the function of a soft magnetic backing layer of the perpendicular magnetic recording medium, and scarcely generates noise. A perpendicular magnetic recording medium using such a substrate also is disclosed. The disk substrate comprises at least a soft magnetic underlayer formed on a nonmagnetic base plate by means of an electroless plating method. The thermal expansion coefficient of the soft magnetic underlayer is larger than a thermal expansion coefficient of the nonmagnetic disk-shaped base plate. A saturation magnetostriction constant ?s satisfies a relation ?s??1×10?5.

Abstract: A method of plating on a glass substrate allowing an electroless plating film with good adhesiveness to be formed by chemically bonding a silane coupling agent in a state of simple adhesion or hydrogen bond to the surface of the glass substrate through dehydration condensation reaction, and a method of manufacturing a magnetic recording medium using the plating method. In the plating method, electroless plating is performed on a glass substrate after sequentially conducting at least the adhesion layer formation that forms an adhesion layer using a silane coupling agent solution, catalyst layer formation, a catalyst activation, and a drying that chemically bonds the silane coupling agent in the adhesion layer to the surface of the glass substrate.

Abstract: A method of manufacture of a glass substrate for a magnetic recording medium, which has both high substrate strength and low alkaline elution, includes an etching process of etching the inner-edge face of a donut-shaped glass substrate having an aluminosilicate composition, formed by removing the center portion of a die-molded disc-shaped glass substrate, and an alkali sealing process of performing alkali sealing treatment by proton substitution of alkali ions in the surface layer of the etched donut-shaped glass substrate. The process is used to manufacture a magnetic recording medium incorporating a glass substrate having a total alkaline elution amount of less than 3.1 ?g/disk, wherein the magnetic recording medium has a transverse rupture strength greater than 132 N.

Abstract: A thermoplastic allyloxymethylstyrene-based resin comprising structural units of the following formulas (I) and (II): as repeating units, wherein R represents a hydrogen atom or a hydrocarbon group, and m and n each denote an integer of 0 or 1 or higher, provided that m and n are not 0 at the same time.

Abstract: A plating method on a glass base plate is disclosed. The method allows an electroless plating film to be formed on a base plate composed of a glass material with excellent adhesivity through a process that removes alkaline and alkaline earth metals on the surface of the base plate. Also disclosed is a method of manufacturing a magnetic recording medium employing the method of plating on a glass base plate. Before forming a plating film in a step of electroless plating, a series of surface treatments are conducted on the surface of the base plate composed of a glass material. The series of surface treatments comprises at least an ultraviolet light irradiation, an etching treatment, an adhesion layer formation treatment, a catalyst layer formation treatment, and a catalyst activation treatment.

Abstract: A method of plating on a glass base plate is disclosed. The method allows a plating film to be formed on a base plate composed of a glass material with excellent adhesivity and homogeneity by means of an electroless plating method, even to a thickness of 1 ?m or more. Before forming the plating film by electroless plating, a series of surface treatments are conducted on the surface of the base plate composed of a glass material. The surface treatments comprises at least a glass activation treatment, a silane coupling agent treatment, a palladium catalyst treatment, a palladium bonding treatment, ab electroless plating to form a preliminary plating film having a thickness in the range of 0.02 ?m to 0.5 ?m, and an annealing at a temperature in the range of 200° C. to 350° C.

Abstract: A method of plating on a glass substrate allowing an electroless plating film with good adhesiveness to be formed by chemically bonding a silane coupling agent in a state of simple adhesion or hydrogen bond to the surface of the glass substrate through dehydration condensation reaction, and a method of manufacturing a magnetic recording medium using the plating method. In the plating method, electroless plating is performed on a glass substrate after sequentially conducting at least the adhesion layer formation that forms an adhesion layer using a silane coupling agent solution, catalyst layer formation, a catalyst activation, and a drying that chemically bonds the silane coupling agent in the adhesion layer to the surface of the glass substrate.

Abstract: An object of the present invention is to provide a plating method on a glass base plate. The method allows forming a plating film on a base plate composed of a glass material with excellent adhesivity and homogeneity by means of an electroless plating method even to a thickness of 1 ?m or more. Before forming a plating film by a step of electroless plating S6, a surface treatment process is conducted on a surface of the base plate composed of a glass material. The surface treatment process comprises at least a step of glass activation treatment S2 to increase quantity of silanol groups on the surface of the base plate at least by a factor of two using an aqueous solution of diluted acid, a step of silane coupling agent treatment S3, a step of palladium catalyst treatment S4, and a step of palladium bonding treatment S5.

Abstract: The method of increasing adhesion between a substrate and an electroless plating layer, and treating the substrate for electroless plating, includes removing any excess alkali from the surface of the substrate, etching the surface of the glass substrate, forming an adhesion layer, forming a catalyst layer on the adhesion layer, and forming an electroless plating film on the catalyst layer.

Abstract: A disk substrate for a perpendicular magnetic recording medium is, disclosed. The substrate exhibits sufficient productivity, serves the function of a soft magnetic backing layer of the perpendicular magnetic recording medium, and scarcely generates noise. A perpendicular magnetic recording medium using such a substrate also is disclosed. The disk substrate comprises at least a soft magnetic underlayer formed on a nonmagnetic base plate by means of an electroless plating method. The thermal expansion coefficient of the soft magnetic underlayer is larger than a thermal expansion coefficient of the nonmagnetic disk-shaped base plate. A saturation magnetostriction constant ?s satisfies a relation ?s??1×10?5.

Abstract: An injection molded thermoplastic magnetic recording substrate a medium formed therewith, and a method thereof is composed of a thermoplastic or allyloxymethylstyrene type resin.

Abstract: A glass substrate is pretreated before forming a Ni—P plating layer thereon. The pretreating process includes degreasing and glass activation treatments of the surface of the nonmagnetic substrate, applying a nickel chelate agent or a nickel soap agent on the substrate surface, a metallizing baking treatment of the nickel-containing agent, an activation treatment of the metallized nickel film to form a nickel adhesion layer, a treatment to form a palladium catalyst layer on the nickel adhesion layer, forming the Ni—P plating layer on the palladium catalyst layer by electroless plating in the range of phosphorus concentration of 1 to 13 wt %, and heat treating the Ni—P plating layer.

Abstract: The gas components in thermoplastic norbornene resin pellets are suppressed below certain levels by drying the resin under vacuum or under the ordinary pressure and under vacuum. A substrate for magnetic recording media is manufactured by injection-molding the resin dried by the method according to the invention. The magnetic recording medium, employing the substrate manufactured according to the invention, includes at least a magnetic layer, a protection layer on the magnetic layer and a liquid lubricant layer on the protection layer. The magnetic recording medium is manufactured by forming these layers, one after another, on the substrate according to the invention.

Abstract: An injection molded thermoplastic magnetic recording substrate a medium formed therewith, and a method thereof is composed of a thermoplastic or allyloxymethylstyrene type resin.

Abstract: A thermoplastic allyloxymethylstyrene-based resin comprising structural units of the following formulas (I) and (II): 1

Abstract: A lubricant for a magnetic recording medium that imparts resistance to degradation, improved lubrication quality and better CSS durability to the medium, even when using a low levitating head. The lubricant is a perfluoropolyether compound having a cyclic triphosphazene end group within the molecule. A magnetic recording medium using at least one perfluoropolyether compound having a cyclic triphosphazene end group within the molecule as a lubricant. A method of making a magnetic recording medium which resists degradation when using a low levitation head including the sequential steps of: forming a foundation layer on a non-magnetic base, forming a magnetic layer on the foundation layer, forming a protection layer on the magnetic layer, and forming a lubrication layer on the protection layer. The lubrication layer includes at least one perfluoropolyether lubricant having a cyclic triphosphazene end group within the molecule.

Abstract: To avoid troubles associated with high-density recording and fast transfer rate, such as decomposition of lubricant involved in a low floating height magnetic head and migration of lubricants involved in high speed rotation of a magnetic recording medium, and to provide a magnetic recording medium which achieves stable resistance to environment and stable lubricating characteristics, a magnetic recording medium includes a base body and the layers formed on the base body, including a non-magnetic metal underlayer, a magnetic layer, a protective layer, and a lubricant layer. The lubricant of the lubricant layer includes a perfluoropolyether liquid lubricant having an alcohol end group(s) and a perfluoropolyether liquid lubricant having an amine end group(s) of tertiary amine structure.

Abstract: A perfluoropolyether liquid lubricant is provided which has an amine functional group at at least one of ends of a chain molecule. A magnetic recording medium using the lubricant assures increased bonding force between a carbon protective layer and a lubricant layer.

Abstract: A titanyloxyphthalocyanine crystal to be used as a charge generation material for an electrophotographic photoreceptor, having a maximum diffraction intensity observed at Bragg angle (2 .theta.) of 9.6.degree..+-.0.2.degree. and clear peaks of diffraction intensity observed at 7.22.degree..+-.0.2.degree., 9.60.degree..+-.0.2.degree., 11.60.degree..+-.0.2.degree., 13.40.degree..+-.0.2.degree., 14.88.degree..+-.0.2.degree.,18.34.degree..+-.0.2.degree., 23.62.degree..+-.0.2.degree., 24.14.degree..+-.0.2.degree., and 27.32.degree..+-.0.2.degree., respectively, in an X-ray diffraction spectrum obtained by performing an x-ray diffraction method using CuK.alpha. as a source of radiation. A method for preparing the crystal includes dispersing a predetermined amount of amorphous titanyloxyphthalocyanine in an aqueous solution in which ionic substances are dissolved, under mechanical force at a temperature of under 50.degree. C.