Abstract: A magnetic tape including: a nonmagnetic support; a substantially nonmagnetic layer containing nonmagnetic powder and a binder; and a magnetic layer containing ferromagnetic powder and a binder, in this order, wherein the magnetic tape has a coefficient of temperature expansion of from 0 to 10×10?6/° C. and a coefficient of humidity expansion of 0 to 7×10?6/% RH each in a transverse direction of the magnetic tape, and the magnetic tape has a dimensional deformation amount of from 0.01 to 0.06% in the transverse direction in case of applying a tensile stress of 1N to the magnetic tape at 60° C. for 50 hours in a longitudinal direction of the magnetic tape.

Abstract: A magnetic recording medium including a nonmagnetic substrate and a magnetic layer, wherein the nonmagnetic substrate is made from a polyethylene naphthalate and has a thickness of 6.5 ?m or smaller, and the magnetic recording medium has a creep deformation of 0.30% or less in a longitudinal direction of the magnetic recording medium under a tensile stress of 15.7 MPa applied in the longitudinal direction at 60° C. for 50 hours.

Abstract: The present invention provides a magnetic recording medium comprising: a non-magnetic substrate; and one or more magnetic layers formed on the non-magnetic substrate, wherein the magnetic recording medium has a loss modulus at 0.5 Hz at a temperature of 130° C. of 0.18 to 0.39 GPa, in order to improve dimensional stability and running stability of a tape, particularly in a high-temperature environment, and thereby improve reliability in recording and reproduction of data, and to provide a method for manufacturing the same. Also, the magnetic recording medium of the present invention attains the object to solve the problem that tension for driving generates nonuniform elongation in the medium, resulting in reduction of running stability because of a thin magnetic recording medium which is reduced the total thickness to increase the capacity of the backup tape per reel by increasing a tape length and increase.

Abstract: A magnetic recording medium comprising: a nonmagnetic support; and a magnetic layer comprising a binder and ferromagnetic powder dispersed in the binder, wherein the magnetic layer has a surface waviness of from 3 to 15%, the surface waviness being calculated by {[(a total of cross-sectional areas of the magnetic layer at a position 5 nm in an above direction from an average plane of surface waviness of the magnetic layer)+(a total of cross-sectional areas of the magnetic layer at a position 5 nm in a below direction from the average plane of surface waviness of the magnetic layer)] (?m2)/a area of a surface of the magnetic layer to be measured (?m2)}×100(%).

Abstract: A magnetic recording medium comprising: a nonmagnetic support; and a magnetic layer containing ferromagnetic powder and a binder, wherein the magnetic layer has on a surface thereof 80 or less depressions having a depth of 10 nm or more per 260×350 ?m2.

Abstract: A magnetic recording and reproducing method of recording or reproducing information using a magnetic recording medium comprising a non-magnetic support having provided thereon at least a magnetic layer containing a ferromagnetic powder dispersed in a binder, which comprises using a magnetic recording medium satisfying the following requirements; having on the surface of the magnetic layer 20/(260×350 ?m2) or less depressions with a depth of 1/3 or more of the recording bit length and a cross-sectional area of 1/2 or more of the reproducing bit area.

Abstract: A magnetic recording medium comprising on a non-magnetic support having thereon, in this order, an adhesive layer comprising a polymer, an undercoating layer comprising an inorganic powder and a binder, and one or more upper magnetic layers each comprising at least a ferromagnetic powder and a binder, the thickness of the upper magnetic layer being in the range of 0.05 to 1.0 .mu.m, the thickness of the undercoating layer being in the range of 0.5 to 5.0 .mu.m, the total thickness of the magnetic recording medium is in the range of 4 to 10 .mu.m, the micro vickers hardness of the non-magnetic support being in the range of 75 to 100 kg/mm.sup.2, and the micro vickers hardness of the undercoating layer being in the range of 25 to 50 kg/mm.sup.2.