Abstract: The magnetic tape has one or more of each of an area A and an area B having different center line average surface roughness Ra measured on a surface of a magnetic layer in a region over a part of the magnetic tape in a longitudinal direction, with a ratio BMag/AMag of 1.20 to 10.00 and a ratio BMag/BBack of equal to or greater than 2.0 in a case where extraction amounts per unit area of a component selected from the group consisting of fatty acid, fatty acid ester, and fatty acid amide extracted from a magnetic layer side of the area A and the area B are defined as AMag and BMag respectively, and an extraction amount per unit area of the above component extracted from a back coating layer side of the area B is defined as BBack.

Abstract: The magnetic tape includes a non-magnetic support, a magnetic layer that includes ferromagnetic powder having an average particle volume of 2,500 nm3 or less on one surface side of the non-magnetic support, and a back coating layer that includes non-magnetic powder on the other surface side of the non-magnetic support, in which the ferromagnetic powder is ferromagnetic powder selected from the group consisting of hexagonal ferrite powder and ?-iron oxide powder, and a ratio (PSD5?m-PSDmag/PSD10?m-PSDbc) of the magnetic layer and the back coating layer is in a range of 0.0050 to 0.20. A magnetic tape cartridge and a magnetic recording and reproducing apparatus include the magnetic tape.

Abstract: Provided are a magnetic tape including a non-magnetic support and a magnetic layer including a ferromagnetic powder, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape. An amount of a fluid lubricant collected by wiping a surface of the magnetic layer by a nonwoven fabric is in a range of 5 to 400 ng/m2 as a value per unit area of the surface of the magnetic layer.

Abstract: The magnetic tape has one or more of each of an area A and an area B having different center line average surface roughness Ra measured on a surface of a magnetic layer in a region over a part of the magnetic tape in a longitudinal direction, with a ratio BMag/AMag of 1.20 to 10.00 and a ratio BMag/BBack of equal to or greater than 2.0 in a case where extraction amounts per unit area of a component selected from the group consisting of fatty acid, fatty acid ester, and fatty acid amide extracted from a magnetic layer side of the area A and the area B are defined as AMag and BMag respectively, and an extraction amount per unit area of the above component extracted from a back coating layer side of the area B is defined as BBack.

Abstract: The magnetic tape includes a non-magnetic support, a magnetic layer that includes ferromagnetic powder having an average particle volume of 2,500 nm3 or less on one surface side of the non-magnetic support, and a back coating layer that includes non-magnetic powder on the other surface side of the non-magnetic support, in which the ferromagnetic powder is ferromagnetic powder selected from the group consisting of hexagonal ferrite powder and ?-iron oxide powder, and a ratio (PSD5?m-PSDmag/PSD10?m-PSDbc) of the magnetic layer and the back coating layer is in a range of 0.0050 to 0.20. A magnetic tape cartridge and a magnetic recording and reproducing apparatus include the magnetic tape.

Abstract: The magnetic tape includes a non-magnetic support, a magnetic layer that includes ferromagnetic powder having an average particle volume of 2,500 nm3 or less on one surface side of the non-magnetic support, and a back coating layer that includes non-magnetic powder on the other surface side of the non-magnetic support, in which the ferromagnetic powder is ferromagnetic powder selected from the group consisting of hexagonal ferrite powder and ?-iron oxide powder, and a ratio (PSD5 ?m-PSDmag/PSD10 ?m-PSDbc) of the magnetic layer and the back coating layer is in a range of 0.0050 to 0.20. A magnetic tape cartridge and a magnetic recording and reproducing apparatus include the magnetic tape.

Abstract: The magnetic recording medium includes a non-magnetic substrate, a non-magnetic layer, and a magnetic layer, wherein the magnetic layer contains a hexagonal strontium ferrite magnetic powder, Mr and t satisfy 0.0020 ?T·m?Mr·t?0.0150 ?T·m, where Mr is the residual magnetic flux density of the magnetic layer, and t is the average thickness of the magnetic layer, L1 satisfies 2 nm?L1?6 nm, where L1 is the average thickness of a first mixed layer that is formed on the surface of the magnetic layer opposite to the non-magnetic layer, L2 satisfies 0.1?L2/t?0.45, where L2 is the average thickness of a second mixed layer that is formed on the surface of the magnetic layer facing the non-magnetic layer.

Abstract: The magnetic tape includes a non-magnetic support, a magnetic layer that includes ferromagnetic powder having an average particle volume of 2,500 nm3 or less on one surface side of the non-magnetic support, and a back coating layer that includes non-magnetic powder on the other surface side of the non-magnetic support, in which the ferromagnetic powder is ferromagnetic powder selected from the group consisting of hexagonal ferrite powder and ?-iron oxide powder, and a ratio (PSD5 ?m-PSDmag/PSD10 ?m-PSDbc) of the magnetic layer and the back coating layer is in a range of 0.0050 to 0.20. A magnetic tape cartridge and a magnetic recording and reproducing apparatus include the magnetic tape.

Abstract: The magnetic recording medium contains, in a magnetic layer, a fatty acid ester and a polyester resin having a number average molecular weight of greater than or equal to 1,000 but less than 20,000, and containing a structural unit derived from a polyvalent carboxylic acid and a structural unit derived from a polyol, as well as 10 mol % to 50 mol % of a structural unit, derived from a cyclic polyvalent carboxylic acid selected from the group consisting of an alicyclic polyvalent carboxylic acid and an aromatic polyvalent carboxylic acid, per 100 mol % of a combined total of the above structural units, and one or more partial structures selected from the group consisting of the following partial structures: wherein each of L1 and L2 independently denotes a divalent connecting group, and each of Z1 and Z2 independently denotes a monovalent group denoted by —OM or a monovalent group denoted by —O?A+.

Abstract: The magnetic recording medium includes a non-magnetic substrate, a non-magnetic layer, and a magnetic layer, wherein the magnetic layer contains a hexagonal strontium ferrite magnetic powder, Mr and t satisfy 0.0020 ?T·m?Mr·t?0.0150 ?T·m, where Mr is the residual magnetic flux density of the magnetic layer, and t is the average thickness of the magnetic layer, L1 satisfies 2 nm?L1?6 nm, where L1 is the average thickness of a first mixed layer that is formed on the surface of the magnetic layer opposite to the non-magnetic layer, L2 satisfies 0.1?L2/t?0.45, where L2 is the average thickness of a second mixed layer that is formed on the surface of the magnetic layer facing the non-magnetic layer.

Abstract: The magnetic recording medium contains, in a magnetic layer, a fatty acid ester and a polyester resin having a number average molecular weight of greater than or equal to 1,000 but less than 20,000, and containing a structural unit derived from a polyvalent carboxylic acid and a structural unit derived from a polyol, as well as 10 mol % to 50 mol % of a structural unit, derived from a cyclic polyvalent carboxylic acid selected from the group consisting of an alicyclic polyvalent carboxylic acid and an aromatic polyvalent carboxylic acid, per 100 mol % of a combined total of the above structural units, and one or more partial structures selected from the group consisting of the following partial structures: wherein each of L1 and L2 independently denotes a divalent connecting group, and each of Z1 and Z2 independently denotes a monovalent group denoted by —OM or a monovalent group denoted by —O?A+.

Abstract: An aspect of the present invention relates to a magnetic recording medium comprising a nonmagnetic layer containing a nonmagnetic powder and a binder and a magnetic layer containing a ferromagnetic powder and a binder in this order on a nonmagnetic support, wherein the binder of the magnetic layer is a mixture of a vinyl chloride copolymer, polyurethane resin, and polyisocyanate, the polyurethane resin having a glass transition temperature ranging from 90 to 130° C. and a storage elastic modulus at 80° C. ranging from 2.5 to 5.0 GPa, the nonmagnetic layer is a radiation-cured layer formed by curing with radiation a radiation-curable composition comprising a nonmagnetic powder and a binder component, the binder component comprising a radiation-curable vinyl chloride copolymer and a radiation-curable polyurethane resin, and the radiation-curable vinyl chloride copolymer and radiation-curable polyurethane resin both have glass transition temperatures ranging from 30 to 100° C.

Abstract: An aspect of the present invention relates to a magnetic tape comprising a nonmagnetic layer containing a nonmagnetic powder and a binder and a magnetic layer containing a ferromagnetic powder and a binder in this order on a nonmagnetic support. The nonmagnetic layer is a radiation-cured layer formed by curing with radiation a given radiation-curable composition. The nonmagnetic layer has a thickness ranging from 0.5 to 1.3 ?m. The relation between the nonmagnetic powder and the binder component contained in the radiation-curable composition satisfies equation (I): 480?(BET specific surface area of the nonmagnetic powder (m2/g)×weight of the nonmagnetic powder (g))/weight of the binder component (g)?650??(I).

Abstract: The present invention aims to provide solid compositions comprising an oil-in-water emulsion that have sufficient hardness and good feel when used, and can sufficiently exhibit the physiological functions of an electrolyte. A solid composition is obtained by preparing an oil-in-water emulsion by combining a solid oil (A), a liquid oil (B), a surfactant (C), a polyhydric alcohol (D), an electrolyte (E), and water (F).

Abstract: An aspect of the present invention relates to a magnetic recording medium comprising a nonmagnetic layer containing a nonmagnetic powder and a binder and a magnetic layer containing a ferromagnetic powder and a binder in this order on a nonmagnetic support, wherein the binder of the magnetic layer is a mixture of a vinyl chloride copolymer, polyurethane resin, and polyisocyanate, the polyurethane resin having a glass transition temperature ranging from 90 to 130° C. and a storage elastic modulus at 80° C. ranging from 2.5 to 5.0 GPa, the nonmagnetic layer is a radiation-cured layer formed by curing with radiation a radiation-curable composition comprising a nonmagnetic powder and a binder component, the binder component comprising a radiation-curable vinyl chloride copolymer and a radiation-curable polyurethane resin, and the radiation-curable vinyl chloride copolymer and radiation-curable polyurethane resin both have glass transition temperatures ranging from 30 to 100° C.

Abstract: An aspect of the present invention relates to a magnetic tape comprising a nonmagnetic layer containing a nonmagnetic powder and a binder and a magnetic layer containing a ferromagnetic powder and a binder in this order on a nonmagnetic support. The nonmagnetic layer is a radiation-cured layer formed by curing with radiation a given radiation-curable composition. The nonmagnetic layer has a thickness ranging from 0.5 to 1.3 ?m. The relation between the nonmagnetic powder and the binder component contained in the radiation-curable composition satisfies equation (I): 480?(BET specific surface area of the nonmagnetic powder (m2/g)×weight of the nonmagnetic powder (g))/weight of the binder component (g)?650??(I).

Abstract: The present invention aims to provide solid compositions comprising an oil-in-water emulsion that have sufficient hardness and good feel when used, and can sufficiently exhibit the physiological functions of an electrolyte. A solid composition is obtained by preparing an oil-in-water emulsion by combining a solid oil (A), a liquid oil (B), a surfactant (C), a polyhydric alcohol (D), an electrolyte (E), and water (F).

Abstract: A magnetic recording medium having a magnetic layer containing magnetic powder provided on a support is disclosed. The magnetic layer possesses a servo band in which a servo signal for controlling tracking of a magnetic head, and a data band on which a data is recorded. The servo signal is magnetized and recorded on the servo band, having been magnetized in one direction of the track direction thereof, in the direction other than the one direction. The thickness of the magnetic layer ranging from 10 to 180 ?m, and variation [standard deviation of Mrt] of the product [Mrt] of the residual magnetism by the thickness of the magnetic field being not more than 30%.

Abstract: A magnetic recording medium including: a back coat layer; a nonmagnetic support; and coated layers including: a nonmagnetic layer containing nonmagnetic powder and a binder; and a magnetic layer containing ferromagnetic powder and a binder, so that the back coat layer, the nonmagnetic support, the nonmagnetic layer and the magnetic layer are provided in this order, wherein the ferromagnetic powder is ferromagnetic hexagonal ferrite powder having an average tabular size of less than 30 nm, and a central plane surface roughness Ra of the magnetic layer, a central plane surface roughness Ra of the back coat layer, a glass transition point of the coated layers, a glass transition point of the back coat layer and a ratio of a Young's modulus of the magnetic layer to a Young's modulus of the back coat layer are defined herein.

Abstract: A substrate for a thin-film magnetic head includes a ceramic base and an undercoat film of amorphous SiC, which is supported on the ceramic base.