176results about "Base layers for recording layers" patented technology

A main object of the present technology is to improve the reliability of a magnetic recording tape by controlling the distribution of the binder in the underlayer.The present technology provides a magnetic recording medium including a magnetic layer, an underlayer, and a base layer in this order, the underlayer containing a chlorine-containing binder, the underlayer including a part having a thickness of 130 nm or less, the part having a chlorine count equal to or more than a threshold described below:[T⁢hreshold]=[⁠an⁢ average⁢ chlorine⁢ count⁢ in⁢ the⁢ underlayer]+6×[a⁢ standard⁢ deviation⁢ determined⁢ in⁢ calculation⁢ of⁢ the⁢ average⁢ chlorine⁢ count].Furthermore, the present technology also provides a magnetic recording medium including a magnetic layer, an underlayer, and a base layer in this order, the underlayer containing a chlorine-containing binder, the underlayer including a part having a thickness of 12% or less of a thickness of the underlayer, the part having a chlorine count equal to or more than the above-described threshold.

A glass is an amorphous oxide glass. An SiO2 content ranges from 56 mol % to 80 mol %, an Li2O content is 2.00 mol % or less, a B2O3 content ranges from 0 mol % to 4 mol %, a total content of MgO and CaO (MgO+CaO) ranges from 9 mol % to 40 mol %, and the oxide glass has a specific gravity of 2.75 g / cm3 or less, and a glass transition temperature of 650° C. or higher.

An information recording medium disc according to an embodiment is a disc having a plate thickness of 0.51 mm or less, and is provided with a substrate and a cover layer. The substrate has one main surface and another main surface, and also has a side wall surface connecting the two main surfaces. A cover layer covers both main surfaces and side wall surfaces of the substrate. The disk has a specific elastic modulus E / d [106 m2 / s2] of 40 or more as calculated from a Young's modulus E [GPa] and a density d [g / cm3]. When 30 [G] impact of 2 [m seconds is applied to the disk in the normal direction of the main surface of the disk substrate in a state in which the inner peripheral end of the disk is fixed, the maximum amplitude caused by vibration in the thickness direction of the outer peripheral end of the disk substrate is 0.25 mm or less.

Disks for use in hard disk drives (HDD) or other magnetic recording apparatus. The disks are configured based on a finding that internal stress within a disk can make the disk more resistant to shock forces. In one example, a disk is provided that has a substrate with a thickness of no more than 0.5 millimeters and an internal stress no less than 300 megapascals. The relatively high internal stress within the substrate of the disk serves to reduce the magnitude of deflections caused by mechanical shocks to an HDD in which the disk is installed, as compared to other disks of equal thickness but with relatively less internal stress. Multi-platter stacks of the disks are described. Methods are also described for fabricating such disks and for rejecting disks that do not meet certain internal stress-based criteria. Substrates are also described.

An alkali-free glass sheet according to the present invention contains, as a glass composition, in mol %, from 60% to 80% of SiO2, from 12% to 15% of Al2O3, from 1.2% to 4% of B2O3, from 0% to 0.5% of Li2O+Na2O+K2O, from 2% to 8% of MgO, from 2% to 11% of CaO, from 0% to 5% of SrO, from 0% to 5% of BaO, and from 10% to 16% of MgO+CaO+SrO+BaO, in which a mol % ratio B2O3 / Al2O3 is from 0.1 to 0.3, a mol % ratio (B2O3+BaO) / SiO2 is from 0.01 to 0.1, and MgO+CaO+SrO+BaO—Al2O3 is from −2% to +2%.

To provide an aluminum alloy sheet for a magnetic disk, an aluminum alloy sheet blank for the magnetic disk, and an aluminum alloy sheet substrate for the magnetic disk, having satisfactory rigidity and capable of suppressing thermal deformation during magnetic film sputtering.SOLUTION: An aluminum alloy sheet for a magnetic disk, comprising: 0.1 to 7.0 mass% of Mg; 0.005 to 1.0 mass% of Cr; 3 to 100 mass ppm of Be; 0.20 mass% or less of Si; 0.05 to 5.9 mass% of at least one or more of Fe, Mn, and Ni in total; and a balance of Al and impurities.SELECTED DRAWING: None

The present invention relates to an aluminum alloy disc blank for a magnetic disc, characterized by being formed of an aluminum alloy containing Fe: 0.005 to 1.800 mass%, the balance consisting of Al and unavoidable impurities, and a flatness change of the aluminum alloy disc blank for a magnetic disc being 2.0 μm or less when the aluminum alloy disc blank for a magnetic disc is kept in the atmosphere at 50°C or lower for 336 hours.

An alkali-free glass includes, in mol % in terms of oxides: SiO2: 63-75%; Al2O3: 10-16%; B2O3: 0-5%; MgO: 0.1-15%; CaO: 0.1-12%; SrO: 0-8%; and BaO: 0-6%. [MgO] / [CaO] is 1.5 or smaller. A value of Formula (A) is 82.5 or larger. A value of Formula (B) is 690 or larger and 800 or smaller. A value of Formula (C) is 100 or smaller. A value of Formula (D) is 20 or smaller. The alkali-free glass has a Young's modulus of 83 GPa or larger and a surface devitrification viscosity ηc of 104.2 dPa·s or higher.

A magnetic recording medium includes a nonmagnetic substrate, an underlayer disposed above the nonmagnetic substrate, and a magnetic recording layer disposed above the underlayer. The magnetic recording layer includes a first magnetic layer disposed above the underlayer, and a second magnetic layer disposed above the first magnetic layer. Each of the first magnetic layer and the second magnetic layer has a granular structure including magnetic grains having a L10 structure and a grain boundary portion. The grain boundary portion of the first magnetic layer includes aluminum nitride, and the grain boundary portion of the second magnetic layer includes hexagonal boron nitride. An aluminum nitride content in the first magnetic layer is in a range of 15 vol % to 35 vol %, and a peak in a B1s spectrum of the grain boundary portion of the second magnetic layer observed using X-ray photoelectron spectroscopy is 191.6 eV or less.

Provided is a magnetic recording medium comprising a non-magnetic support and a magnetic layer containing ferromagnetic powder, and further comprising a non-magnetic layer containing non-magnetic powder between the non-magnetic support and the magnetic layer. The average pore diameter of the magnetic layer and the non-magnetic layer is 30.0 nm or less, and the standard deviation of the pore diameter distribution of the magnetic layer and the non-magnetic layer is 30.0 nm or less.

To provide a magnetic recording medium in which perpendicular orientation of a magnetic recording layer is enhanced and further high recording density is made possible, and to provide a magnetic recording and reproducing device provided with the magnetic recording medium.SOLUTION: A magnetic recording medium 1 according to the present invention includes an underlayer 30, a seed layer 40, and a magnetic recording layer 60 in this order on a non-magnetic substrate 10, wherein the seed layer 40 contains two elements phase-separated from each other, one phase of an element α mainly has a columnar crystal of an fcc structure, and the other phase of an element β mainly has an amorphous structure, the underlayer 30 includes a first underlayer 31, a second underlayer 32, and a third underlayer 33 from the side of the non-magnetic substrate 10, the first underlayer 31 mainly contains any of Ru, Cr, and Ni, the second underlayer 32 mainly contains the one element α, and the third underlayer 33 mainly contains any of Ru, Cr, and Mo.SELECTED DRAWING: Figure 1

A magnetic tape according to an embodiment of the present technology is a magnetic tape including a base material and a magnetic layer provided on one of main surfaces of the base material, in which the base material is formed of polyethylene naphthalate (PEN), a total thickness of the magnetic tape is 4.9 μm or more and 5.4 μm or less, and a loop stiffness of the magnetic tape in a width direction thereof is 1.1 mg / μm or more and 1.4 mg / μm or less.

To enable data to be satisfactorily recorded and / or reproduced when the data is recorded and / or reproduced while changing a head tilt angle during running of a magnetic tape after storing the magnetic tape.SOLUTION: A magnetic tape device is provided. An angle θ formed by the axis of the element array of a magnetic head with respect to the width direction of the magnetic tape is changed during running of the magnetic tape in the magnetic tape device. When a maximum value of an absolute value of a difference between a servo band spacing obtained before storage in a predetermined environment and a servo band spacing obtained after storage in the environment for a storage time T is defined as A and T is set to be a plurality of predetermined times, a medium life calculated by a linear function of A and a logarithm loge T of T, that are derived from a value of A and a value of the logarithm loge T of T obtained for each T is 5 years or longer. The medium life is T when A satisfies a prescribed formula.SELECTED DRAWING: None

In one embodiment, a polishing liquid for magnetic disk substrates is provided that can reduce waviness on the surface of a magnetic disk substrate. [Solution] In one aspect, the present disclosure relates to a polishing liquid for magnetic disk substrates, which contains silica particles (component A) and an acid (component B), and in which the ammonia desorption maximum temperature of the silica particles measured by an ammonia temperature-programmed desorption method is 150°C or higher and 250°C or lower.

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder, in which a half-width of a frictional force, which is measured on a surface of the magnetic layer with a lateral force microscope, is 200 mV or less, and standard deviation σ of the half-width of the frictional force in a width direction of the surface of the magnetic layer is 50.0 mV or less.

The present invention provides a magnetic tape having a non-magnetic support and a magnetic layer containing a strong magnetic powder, in a small-angle X-ray scattering spectrum of the non-magnetic support obtained by small-angle X-ray scattering measurement, in a region where q is 0.5 to 1.5 A-1, a ratio of a scattering intensity I at a q value q max at which a maximum of a rate of change of the scattering intensity is present to a scattering intensity I max at which a minimum of the rate of change of the scattering intensity is present is 2.7 or more, q min < 1.5 A-1 min < 0.5 A-1 max < 0.5 A-1 min < 0.5 A-1 min < 0.5 A-1 max and a glass transition temperature Tg of the non-magnetic support is 140°C or more, a magnetic tape cartridge including the magnetic tape, and a magnetic recording and reproducing apparatus.

To provide a method for producing a magnetic recording medium capable of having a magnetic layer with high crystal orientation and few defects, a magnetic recording medium, and a magnetic storage device.SOLUTION: A method of producing a magnetic recording medium 1 includes: a step of forming a magnesium oxide underlayer 20 on a surface of a substrate 10 by a sputtering method with using a target containing magnesium oxide; and a step of forming a magnetic layer 30 on the surface side of the magnesium oxide underlayer 20, in which the target containing the magnesium oxide is heated to more than 600°C when forming the magnesium oxide underlayer 20.SELECTED DRAWING: Figure 1

To provide a magnet tape which may contribute to operational stability improvement of a drive during recording and / or reproduction after prolonged storage.SOLUTION: A magnetic tape comprising a non-magnetic support body and a magnetic layer containing ferromagnetic powder, a magnetic tape cartridge comprising the magnetic tape, and a magnetic tape device are provided. The number of recesses with circle-equivalent diameters of 0.15 to 0.25 μm, inclusive, present on a surface of the magnetic layer is 100 to 2500, inclusive, per 40 μm×40 μm area. A standard deviation σ of the number of recesses in a width direction of the surface of the magnetic layer is 100 or less.SELECTED DRAWING: None

To provide a magnetic tape that is excellent in running stability in recording and / or playing back data at different head inclination angles in a high temperature and high humidity environment.SOLUTION: There is provided a magnetic tape in which an edge weave amount of a tape edge on at least one side of the magnetic tape is 1.5 μm or less, in an environment of a temperature of 32°C and relative humidity of 80%, frictional force F45° on a surface of a magnetic layer with respect to an LTO8 head measured at a head inclination angle of 45° is 4 gf or more and 15 gf or less, and a standard deviation of the frictional force F on the surface of the magnetic layer with respect to the LTO8 head measured at head inclination angles of 0°, 15°, 30°, and 45° is 10 gf or less. Also there are provided a magnetic tape cartridge including the magnetic tape, and a magnetic tape device including the magnetic tape.SELECTED DRAWING: None

The embodiment of the invention relates to a magnetic recording device. According to one embodiment, a magnetic recording apparatus includes: a disk-shaped recording medium; a magnetic head including a recording element, a light source, a light emitting element, and a sensor; and a controller including an inspection circuit that detects a height of a defect based on an output of the sensor, a memory that records the height of the defect, a setting circuit that sets the height of the defect on a track of the recording medium in which the defect is located with respect to a traveling direction of the magnetic head, and a light source control circuit that controls the light source to light the defect. And a light source control circuit that sets an upstream-side recording / reproduction prohibited sector on the upstream side of the defect and sets a downstream-side recording / reproduction prohibited sector on the downstream side of the defect, the downstream-side recording / reproduction prohibited sector having a longer length in the track direction than the upstream-side recording / reproduction prohibited sector, and that controls the output of the light source.

An alkali-free glass includes, in mol % in terms of oxides: SiO2: 63-75%; Al2O3:10-16%; B2O3: 0-5%; MgO: 0.1-15%; CaO: 0.1-12%; SrO: 0-8%; and BaO: 0-6%. [MgO] / [CaO] is 1.5 or smaller. A value of Formula (A) is 82.5 or larger. A value of Formula (B) is 690 or larger and 800 or smaller. A value of Formula (C) is 100 or smaller. A value of Formula (D) is 20 or smaller. The alkali-free glass has a Young's modulus of 83 GPa or larger and a surface devitrification viscosity ηc of 104.2 dPa·s or higher.

A substrate for a magnetic disk has a disk shape. The substrate has a diameter D of 85 mm or more and 100 mm or less, and a thickness T of 0.3 mm or more and 0.5 mm or less. Regarding a Young's modulus E and the thickness T of the substrate, a value of E·T3 is 3 to 18 (GPa·mm3). A material of the substrate has a Q-value of 1500 or less under conditions of 3000 Hz and room temperature.

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. An arithmetic average curvature Spc of a peak point specified in ISO 25178 on a surface of the magnetic layer is 0.30 (1 / μm) or more and 0.70 (1 / μm) or less, and standard deviation a of the Spc in a width direction of the surface of the magnetic layer is 0.15 (1 / μm) or less.

A magnetic recording medium is described that includes a substrate and an amorphous soft underlayer (SUL). An Ni—Pt seed layer is formed on the SUL where the Pt atoms have substitutionally replaced at least some of the Ni atoms within an Ni lattice structure of the Ni—Pt to form a solid solution of Ni—Pt. In some examples, the Ni—Pt seed layer is formed of Ni40Pt60. An Ru interlayer is formed on the seed layer. In some examples, the Ni—Pt seed layer has a lattice mismatch with the Ru interlayer of 0.4% or less. A magnetic recording layer is formed on the Ru interlayer. Additional layers or films may be provided. The medium may be configured for use with perpendicular magnetic recording (PMR). A data storage device that includes the magnetic recording medium is described. Methods for fabricating the magnetic recording medium are set forth herein as well.

The present invention relates to an aluminum alloy disc blank for a magnetic disc, characterized by being formed of an aluminum alloy containing Mg: 3.40 to 3.90 mass%, the balance consisting of Al and unavoidable impurities, the aluminum alloy disc blank for a magnetic disc having an electrical conductivity of 36.0% IACS or more.

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.

A glass for magnetic recording medium substrate is an amorphous oxide glass. In terms of mol %, SiO2 content ranges from 45 to 68%, Al2O3 from 5 to 20%, total content of SiO2 and Al2O3 60 to 80%, B2O3 from 0 to 5%, MgO from 3 to 28%, CaO from 0 to 18%, total content of BaO and SrO 0 to 2%, total content of alkali earth metal oxides from 12 to 30%, total content of alkali metal oxides from 3.5 to 15%, and at least one kind selected from the group made of Sn oxide and Ce oxide being included, a total content of Sn oxide and Ce oxide ranges from 0.05 to 2.00%, a glass transition temperature ≥625° C., a Young's modulus ≥83 GPa, a specific gravity ≤2.85, and an average linear expansion coefficient at 100 to 300° C.≥48×10−7 / ° C.

To provide a magnetic tape that is excellent in running stability in recording and / or playing back data at different head inclination angles in a high temperature and high humidity environment.SOLUTION: There is provided a magnetic tape in which C-H-derived C density is 45 atom% or more and 65 atom% or less and is calculated from a C-H peak area ratio in a C1s spectrum obtained through X-ray photoelectron spectroscopic analysis performed at a photoelectron take-out angle of 10 degrees on a surface of a magnetic layer, in an environment of a temperature of 32°C and relative humidity of 80%, frictional force F45° on the surface of the magnetic layer with respect to an LTO8 head measured at a head inclination angle of 45° is 4 gf or more and 15 gf or less, and a standard deviation of the frictional force F on the surface of the magnetic layer with respect to the LTO8 head measured at head inclination angles of 0°, 15°, 30°, and 45° is 10 gf or less. Also there are provided a magnetic tape cartridge including the magnetic tape, and a magnetic tape device including the magnetic tape.SELECTED DRAWING: None