10results about "Disk carriers" patented technology

A substrate for a magnetic disk, characterized by being composed of an aluminum alloy containing one or two or more of Fe: 8.5 mass% or less, Mn: 2.5 mass% or less, Ni: 6.5 mass% or less, and Mg: 4.5 mass% or less, with the remainder composed of Al and unavoidable impurities, a resonance frequency being f (Hz), a density being p (g / cm 3 ), and a plate thickness being t (mm), (f x p / t) being 3800 or more, and a magnetic disk using the substrate for a magnetic disk.

The present invention relates to a sputtering target for a magnetic recording medium containing Co and Pt as metal components and containing at least one oxide. In the present invention, as an essential oxide for improving magnetic separation, tungsten oxide and / or molybdenum oxide is contained, and the content of the essential oxide is 15 vol% or less. As the oxide in the sputtering target, other oxides such as B2O3 can also be contained as optional oxides, and in this case, the total oxide content is preferably 20 vol% or more and 50 vol% or less. In the present invention, by applying the essential oxide, the total oxide content can be appropriately set while ensuring magnetic separation. According to the present invention, a granular thin film composed of a CoPt-based alloy having good magnetic separation can be formed.

To provide an alkali-free glass panel that has excellent productivity and also has sufficiently high strain points and Young's moduli.SOLUTION: An alkali-free glass panel has a glass composition containing, in mol%, SiO2 64-72%, Al2O3 11-15%, B2O3 0-4%, Li2O+Na2O+K2O 0-0.5%, MgO 5-12%, CaO 7-12%, SrO 0-1%, BaO 0-1%, and MgO+CaO+SrO+BaO 15-19% with the mol% ratio B2O3 / Al2O3 of 0.1-0.4 and the mol% ratio MgO / CaO of 0.1-1.5.SELECTED DRAWING: Figure 1

To provide a substrate for magnetic recording media that has high heat resistance and specific modulus, and has low manufacturing costs. [Solution] The magnetic recording medium substrate according to this disclosure has a heat-resistant film on the surface of a steatite sintered body made of one or more alloys selected from the group consisting of SiO2, SiC, Si3N4, and Al2O3.

To provide a substrate for magnetic recording media that has high heat resistance and specific modulus, and has low manufacturing costs. [Solution] The magnetic recording medium substrate according to this disclosure includes a steatite sintered body.

This spindle motor comprises a shaft, a base part, a stator core, a rotor, and a bearing part. The shaft extends along a center axis extending in the vertical direction. The shaft has a screw hole extending axially downward from the upper end thereof. The screw hole has a screw section screwed to a screw. The bearing part comprises an upper annular member, a lower annular member, and a sleeve. The upper annular member and the lower annular member protrude radially outward from an outer peripheral surface of the shaft and are disposed to be spaced apart from each other in the axial direction. The sleeve has an insertion hole into which the shaft is inserted. The sleeve covers the outer peripheral surface of the shaft, axially extends, and is formed in a cylindrical shape. The upper end of the upper annular member is disposed further axially downward than the lower end of the screw section.

To provide a highly reliable method for inspecting magnetic recording media and a method for manufacturing magnetic recording media. [Solution] A method for inspecting a magnetic recording medium 42 having a magnetic layer on a non-magnetic substrate, wherein the inspection apparatus 41 identifies a defect portion having a non-periodic convex shape based on an output signal obtained by scanning the surface of the magnetic recording medium with an inspection head 50 having a thermosensitive resistance element using an inspection head drive mechanism 60. The convex shape has a height of 0.1 nm to 1.5 nm and a width of 1 μm to 15 μm.

The objective is to provide a magnetic recording device that can prevent problems caused by buildup products and improve recording density. [Solution] According to the embodiment, the magnetic recording device comprises a disk-shaped recording medium having a recording surface coated with a lubricant, a magnetic head including a recording element, a light source, and a light-emitting element that irradiates light onto the recording surface of the recording medium, a light source control circuit that controls the drive current value of the light source, a cleaning execution circuit that performs a cleaning operation to remove buildup products adhering to the magnetic head, and a controller including a setting circuit that sets the cleaning interval for performing the cleaning operation.

There is provided a fluorine-containing ether compound represented by the following formula:wherein R3 and R4 are the same or different perfluoropolyether chains; R2 and R5 are each independently a divalent linking group having one or more polar groups; R1 and R6 are each independently an end group containing a tertiary amine, and represented by —X—NR7R8 (X is a divalent hydrocarbon group having 1 to 5 carbon atoms; R7 and R8 are the same or different saturated aliphatic groups; and R7 and R8 may form a ring structure together with a nitrogen atom).