Abstract: Provided are: a magnetic recording medium including a non-magnetic support and a magnetic layer containing a ferromagnetic powder, in which the ferromagnetic powder is an ?-iron oxide powder, a vertical switching field distribution SFD of the magnetic recording medium is 0.20 or more and 3.00 or less at a measurement temperature of 25° C., and an inclination of SFD obtained from SFD at a measurement temperature of 10° C., SFD at a measurement temperature of 25° C., and SFD at a measurement temperature of 40° C. is 0.003° C.?1 or more and 0.080° C.?1 or less; a magnetic tape cartridge including the magnetic recording medium which is a magnetic tape; and a magnetic recording and reproducing device including the magnetic recording medium.

Abstract: A tape-shaped magnetic recording medium is provided with a base, an underlayer provided on the base, and a magnetic layer provided on the underlayer including magnetic powder including hexagonal ferrite. The underlayer and the magnetic layer include lubricant. The magnetic layer includes a surface provided with a large number of holes, and arithmetic average roughness Ra of the surface is 2.5 nm or smaller. A BET specific surface area of a whole of the magnetic recording medium in a state in which the lubricant is removed is 3.5 m2/mg or larger. A square ratio in a vertical direction is 65% or larger, an average thickness of the magnetic layer is 90 nm or smaller, and an average thickness of the magnetic recording medium is 5.6 ?m or smaller.

Abstract: The magnetic recording medium is a particulate magnetic recording medium for heat-assisted recording, as well as includes a magnetic layer comprising ferromagnetic powder and binder on a nonmagnetic organic material support and a heat-diffusing layer of higher thermal conductivity than the magnetic layer between the nonmagnetic organic material support and the magnetic layer.

Abstract: A magnetic tape produced by cutting a magnetic sheet with a wide breadth into a tape having a predetermined width using a cutting device, in which the magnetic sheet has a magnetic layer containing magnetic powder and a hinder formed on one surface of a non-magnetic substrate having a thickness of 4 ?m or less, and a center line average height (Ra) along a roughness curve of a cut edge of the magnetic tape is from 0.08 to 0.25 ?m.

Abstract: According to one embodiment, a magnetic recording medium includes a data region and a servo region adjacent to the data region and including a magnetic recording layer, the magnetic recording layer including first and second patterned regions adjacent to each other, the first patterned region including a first nonmagnetic matrix and first magnetic particles dispersed in the first nonmagnetic matrix and having magnetization oriented in a first direction, the second patterned region includes a second nonmagnetic matrix and second magnetic particles dispersed in the second nonmagnetic matrix and having magnetization oriented in a second direction opposite to the first direction, sizes of the first magnetic particles being smaller than sizes of the second magnetic particles.

Abstract: An aspect of the present invention relates to a mixture of a sulfonate group-containing compound denoted by general formula (1) with a protonic acid: wherein, in general formula (1), X denotes a divalent linking group; each of R1 and R2 independently denotes an alkyl group comprising at least one hydroxyl group and equal to or more than three carbon atoms or an aralkyl group comprising at least one hydroxyl group and equal to or more than eight carbon atoms; and M denotes a cation.

Abstract: A magnetic tape produced by cutting a magnetic sheet with a wide breadth into a tape having a predetermined width using a cutting device, in which the magnetic sheet has a magnetic layer containing magnetic powder and a hinder formed on one surface of a non-magnetic substrate having a thickness of 4 ?m or less, and a center line average height (Ra) along a roughness curve of a cut edge of the magnetic tape is from 0.08 to 0.25 ?m.

Abstract: According to one embodiment, a magnetic recording medium includes a data region and a servo region adjacent to the data region and including a magnetic recording layer, the magnetic recording layer including first and second patterned regions adjacent to each other, the first patterned region including a first nonmagnetic matrix and first magnetic particles dispersed in the first nonmagnetic matrix and having magnetization oriented in a first direction, the second patterned region includes a second nonmagnetic matrix and second magnetic particles dispersed in the second nonmagnetic matrix and having magnetization oriented in a second direction opposite to the first direction, sizes of the first magnetic particles being smaller than sizes of the second magnetic particles.

Abstract: A magnetic recording tape includes an elongated substrate and a magnetic side. The magnetic side includes a support layer formed over the substrate and a magnetic recording layer formed over the support layer to define a magnetic recording surface opposite the substrate. The magnetic recording layer includes magnetic particles and a lubricant and supports a net uncompressed density of at least 30 MB/in2. The magnetic side has an extracted BET surface area of greater than 1.0 m2/g.

Abstract: A magnetically-activatable sheet product is provided comprising a pair of laminated outer sheets at least one of which is provided with a pigment/binder primer coat on its inward facing surface, between which is a magnetic layer comprising magnetically-activatable particles in a binder matrix, the outer sheets having sufficient opacity to mask the appearance of the magnetic layer.

Abstract: Subject: A process for producing a magnetic recording medium, having a magnetic recording layer and a protective layer on a substrate which is a non-magnetic support, wherein the medium is able to greatly inhibit migration of a lubricant from the protective layer to the surface of the metal pressing plate having a mirrored finish in a hot pressing step during production of the magnetic recording medium, while maintaining satisfactory scratch resistance, suitable adhesion with the magnetic recording layer and the protective layer, and excellent read and write properties of the magnetic recording medium.

Abstract: A dual-layer magnetic recording tape having a non-magnetic substrate with a front side and a back side, a lower support layer formed over the front side and a magnetic recording layer formed over the lower support layer. The magnetic recording layer includes magnetic metallic pigment particles having an average particle length up to about 35 nm, and a coercivity of at least about 2,000 Oersteds. The magnetic tape has a BB noise less than about ?91 dB at about 93 kfci.

Abstract: The present invention relates to ferromagnetic metal particles having an average major axis diameter (L) of 10 to 100 nm which satisfy a relationship between the average major axis diameter (L) and a particle SFD represented by the following formula: Particle SFD?0.0001 L2?0.0217 L+1.75; a process for producing the ferromagnetic metal particles; and a magnetic recording medium using the ferromagnetic metal particles.

Abstract: A compound represented by the Formula below is provided. (in Formula (1), X denotes a divalent linking group, R1 and R2 independently denote an alkyl group having 3 or more carbons and having at least one hydroxy group or an aralkyl group having 8 or more carbons and having at least one hydroxy group, the alkyl group and aralkyl group may have a substituent, and M denotes a hydrogen atom or a cation). There is also provided a polyurethane resin obtained by polymerization of a polyisocyanate and a polyol that includes the compound. There is also provided a magnetic recording medium that includes a non-magnetic support and, above the support, at least one magnetic layer including a ferromagnetic powder dispersed in a binder that includes the polyurethane resin.

Abstract: A magnetic recording medium has a cut surface along an edge of the magnetic recording medium and includes, in the following order: a nonmagnetic support having a Young's modulus of 8 GPa or more in a width direction; a nonmagnetic layer formed by radiation curing a dispersion of a radiation curing compound and a nonmagnetic powder in a binder; and a magnetic layer containing a ferromagnetic powder dispersed in a binder, and the cut surface has a waviness of from 20% to 50% as defined herein.

Abstract: The present invention provides a magnetic recording medium comprising an undercoating layer comprising a radiation-curable compound that has been cured by irradiation with radiation, a nonmagnetic layer comprising a nonmagnetic powder and a binder, and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support, wherein the magnetic layer and/or the nonmagnetic layer comprise a carbonic ester denoted by general formula (1), and the undercoating layer has an indentation hardness lower than that of the nonmagnetic support. In general formula (1), each of R1 and R2 independently denotes a saturated hydrocarbon group, with a total number of carbon atoms in R1 and R2 being equal to or higher than 12 but equal to or lower than 50.

Abstract: The magnetic recording medium comprises a magnetic layer comprising a ferromagnetic powder and a binder on a nonmagnetic support. The magnetic layer has an average surface roughness Ra, measured by an atomic force microscope, ranging from 2.0 to 3.5 nm and an indentation hardness ranging from 0.49 GPa to 0.78 GPa, as well as further comprises a carbonic ester having a molecular weight of 360 to 460 that is denoted by general formula (1). In general formula (1), R1 denotes a saturated hydrocarbon group having a branched structure, and R2 denotes a saturated hydrocarbon group having a linear structure with 14 to 20 carbon atoms.

Abstract: Provided is a magnetic recording medium which causes a reduction of transition noises and has a high productivity, and a method of manufacture thereof. The method of manufacturing a magnetic recording medium, comprising: fixing a polymerization initiator on a support by microcontact printing, forming a grafted polymer pattern by bringing a compound having a polymerizable unsaturated bond into contact with the polymerization initiator fixed on the support followed by graft polymerization of the compound, and forming a magnetic region by coating, onto the pattern, an alloy-particle-containing liquid which contains alloy particles capable of forming a CuAu pattern or Cu3Au pattern ferromagnetic ordered alloy, and further subjecting the resultant to annealing processing, thereby forming a plurality of magnetic regions physically independent of each other.

Abstract: The present invention provides a magnetic recording medium which has a thin film magnetic layer considerably excellent in surface smoothness, and is excellent in electromagnetic conversion property. A magnetic recording medium comprising a non-magnetic support, a lower non-magnetic layer comprising at least a non-magnetic powder and a binder resin on one surface of the non-magnetic support, and a magnetic layer comprising at least a ferromagnetic powder and a binder resin on the lower non-magnetic layer, wherein when the magnetic recording medium is subjected to extraction treatment with water, 7 to 23 ?g of PO43? ions are extracted per 10 mm3 of the volume of the lower non-magnetic layer of the magnetic recording medium.

Abstract: A magnetic recording medium is provided that comprises a non-magnetic support and, in order thereabove, a radiation-cured layer cured by exposing a layer comprising a radiation curing compound to radiation, and a magnetic layer comprising a ferromagnetic powder dispersed in a binder, the radiation-cured layer comprising an inorganic powder that has been surface treated with a silane coupling agent.

Abstract: Improvements to magnetic recording device including magnetic recording media are described. The improvements include the addition of copper to the recording layer as well as improved underlayers. In addition, improved manufacturing processes and magnetic/recording properties for media through heating and oxidation are described.

Abstract: A magnetic recording medium is provided that comprises a non-magnetic support and, in order thereabove, a radiation-cured layer cured by exposing a layer comprising a radiation curing compound to radiation and a magnetic layer comprising a ferromagnetic powder dispersed in a binder, the radiation curing compound being a compound having a carbonate bond. There is also provided a radiation curing composition comprising a radiation curing compound having a carbonate bond.

Abstract: A perpendicular magnetic recording medium at least comprises a perpendicular magnetic recording layer and a backing layer backing the perpendicular magnetic recording layer. The backing layer has an in-plane magnetization and is formed of a ferrimagnetic material having a compensation temperature in the vicinity of a recording/reproducing temperature in which reproducing of magnetic information is made from the perpendicular magnetic recording layer. A magnetic storage apparatus for recording and reproducing magnetic information using the perpendicular magnetic recording medium is also disclosed.

Abstract: An aspect of the present invention provides a magnetic recording medium comprising following layers in this order on at least one surface of a nonmagnetic support: a nonmagnetic layer including a nonmagnetic powder and a binder; and a magnetic layer including a magnetic powder and a binder, wherein the nonmagnetic support has an enthalpy relaxation (?H) equal to or more than 0.5 J/g and equal to or less than 2.0 J/g. According to the aspect of the present invention, a magnetic recording medium is provided that is superior in electromagnetic conversion (e.g., with a high S/N ratio for surface recording density) and running durability (e.g., with a small number of dropouts and a low error rate).

Abstract: A dual-layer magnetic recording medium including a non-magnetic substrate having a front side and a back side, a lower support layer formed over the front side and a magnetic upper recording layer formed over the lower layer, wherein the magnetic layer contains a volume concentration of at least about 35% of a magnetic metallic particulate pigment having a coercivity of at least about 2000 Oersteds (Oe), and a binder system for the pigment. The magnetic recording medium exhibits an orientation ratio greater than 2.0, a pulsewidth (PW50) value of less than about 500 nm, and a remanence-thickness product, Mr*t, of less than about 5.0 memu/cm2.

Abstract: The coating-type magnetic recording medium has a non-magnetic layer mainly composed of a non-magnetic powder and binder, and a magnetic layer mainly composed of a ferromagnetic powder and a binder, which are stacked in this order on a non-magnetic substrate, wherein dispersion ?L/L of long-axis length of all ferromagnetic powder particles contained in the magnetic layer falls in a range of ?L/L?±10%, where L is an average long-axis length and ?L is a standard deviation thereof, and dispersion ?W/W of short-axis length of all ferromagnetic powders contained in the magnetic layer falls in a range of ?W/W?±15%, where W is an average short-axis length and ?W is a standard deviation thereof. The average long-axis length L is typically adjusted within the range of 0.08 ?m and 0.12 ?m, and the Switching Field Distribution (SFD) of the medium is adjusted to 0.25 or less.