Abstract: A magnetic recording medium comprising a non-magnetic support and a magnetic layer containing a binder and a ferromagnetic metal powder dispersed in the binder, wherein the binder contains a polyurethane resin obtained from a polyester polyol, a chain extender, and an organic diisocyanate, and the magnetic layer has a product Π of coercive force Hc (kA/m) in an in-plane, longitudinal direction and magnetic flux Øm (T&mgr;m) in a range of from 400 to 800.

Abstract: A magnetic recording medium is disclosed, comprising a support having thereon a lower layer containing a nonmagnetic powder or a ferromagnetic powder dispersed in a binder, and at least a magnetic layer containing a ferromagnetic powder dispersed in a binder provided on the lower layer, wherein the binder contains a polyurethane resin obtained from a polyester polyol comprising a specific diol, a chain extending agent and an organic diisocyanate, and the magnetic layer surface has a C/Fe peak ratio of from 7 to 11.

Abstract: Provided is a magnetic recording medium that exhibits excellent electromagnetic characteristics especially in recording and reproducing systems using an MR head, as well as has excellent long-term preservation property. The magnetic recording medium comprises a lower layer comprising a nonmagnetic powder or a ferromagnetic powder and a binder and at least one magnetic layer thereover comprising a ferromagnetic powder and a binder on a support.

Abstract: Provision of a highly reliable magnetic recording medium with able to record further high density recording, usable advantageously as a magnetic tape for recording computer data, and having a further improved SNR, and a method for reproducing signals magnetically recorded on a magnetic recording medium to reproduce more desirably magnetic recording such as computer data with high density recording or the like. The magnetic recording medium having, on either side of a flexible nonmagnetic support, a nonmagnetic layer containing a nonmagnetic powder and a binder, and a magnetic layer containing a ferromagnetic powder and a binder, having a thickness in the range of from 0.2 to 0.6 &mgr;m in this order, where a laminated head is used for reproduction. The method for reproducing signals magnetically recorded medium having, on either side of a flexible nonmagnetic support, a nonmagnetic layer containing a nonmagnetic powder and a binder, and a magnetic layer, with a thickness ranging from 0.2 to 0.

Abstract: Provided is a magnetic recording medium having good electromagnetic characteristics, particularly both improved high-density recording characteristics and good durability, and particularly a C/N ratio that is markedly improved in the high-density recording region. A magnetic recording medium comprising a nonmagnetic lower layer and a magnetic layer provided in this order on a support wherein said magnetic layer comprises a ferromagnetic metal powder or a ferromagnetic hexagonal ferrite powder and a binder and has a coercive force equal to or higher than 143 kA/m. Said magnetic recording medium is a medium for recording signals having a surface recording density ranging from 0.2 to 2 Gbit/inch2; said support has a thickness equal to or less than 5.

Abstract: A magnetic recording tape is described, which comprises a plastic support having provided thereon a magnetic layer comprising a ferromagnetic metal powder dispersed in a binder, wherein the magnetic layer has the product P of the coercivity Hc (Oe) in the in-plane machine direction of the tape and the magnetic flux &phgr;m (G·cm) of from 100 to 160.

Abstract: A magnetic recording medium is disclosed, comprising a support having thereon a lower layer containing a nonmagnetic powder or a ferromagnetic powder dispersed in a binder, and at least a magnetic layer containing a ferromagnetic powder dispersed in a binder provided on the lower layer, wherein the binder contains a polyurethane resin obtained from a polyester polyol comprising a specific diol, a chain extending agent and an organic diisocyanate, and the magnetic layer surface has a C/Fe peak ratio of from 7 to 11.

Abstract: Provided is a magnetic recording medium having good electromagnetic characteristics, particularly both improved high-density recording characteristics and good durability, and particularly a C/N ratio that is markedly improved in the high-density recording region. A magnetic recording medium comprising a nonmagnetic lower layer and a magnetic layer provided in this order on a support wherein said magnetic layer comprises a ferromagnetic metal powder or a ferromagnetic hexagonal ferrite powder and a binder and has a coercive force equal to or higher than 143 kA/m. Said magnetic recording medium is a medium for recording signals having a surface recording density ranging from 0.2 to 2 Gbit/inch2; said support has a thickness equal to or less than 5.

Abstract: A magnetic recording medium is disclosed, comprising a nonmagnetic support having thereon at least two coating layers which comprise:a lower coating layer mainly comprising (1) at least one particles selected from nonmagnetic particles or soft magnetic particles and (2) a binder, formed on the support, anda magnetic layer comprising ferromagnetic particles dispersed in a binder, formed on the lower coating layer,wherein at least said lower coating layer contains a polyurethane resin having a cyclic structure and containing an ether group, and said nonmagnetic particles or soft magnetic particles contained in said lower coating layer have an average long axis length of from 0.04 to 0.20 .mu.m and an acicular ratio (long axis/short axis) of from 2 to 10.It is a high-output, low-noise magnetic recording medium having excellent magnetic-layer surface properties and satisfactory running durability.

Abstract: A magnetic recording medium comprises a non-magnetic substrate, a lower coating layer, which is overlaid upon the non-magnetic substrate and primarily contains a binder and inorganic particles dispersed in the binder, and a magnetic layer, which is overlaid upon the lower coating layer and is constituted of at least a single layer. The magnetic layer contains at least a binder and ferromagnetic metal particles dispersed in the binder. The thickness of the magnetic layer falls within the range of 0.05 .mu.m to 0.5 .mu.m. The surface roughness of a top magnetic layer is at most 3 nm. The lower coating layer contains a fatty acid. An increase in the number of small protrusions, which have a height of at least 30 nm, does not occur substantially on the surface of the magnetic layer after the magnetic recording medium has been stored for seven days under environmental conditions of a temperature of 60.degree. C. and a relative humidity of 90%.

Abstract: A magnetic recording medium is disclosed, comprising a magnetic layer mainly comprising a ferromagnetic powder and a binder resin formed on at least one side of a non-magnetic support, wherein said magnetic layer has a thickness of from 0.05 .mu.m to 0.8 .mu.m, said ferromagnetic powder has an average long axis length of from 0.05 .mu.m to 0.20 .mu.m, and said binder resin comprises a polyurethane having a radius of gyration from 5 to 25 nm in cyclohexanone.

Abstract: A cleaning medium for magnetic recording devices comprises a non-magnetic substrate and a lower coating layer, which is overlaid upon the non-magnetic substrate and primarily contains a binder and non-magnetic inorganic particles dispersed in the binder. The cleaning medium also comprises a cleaning layer, which is overlaid upon the lower coating layer and contains a binder and inorganic particles dispersed in the binder, the inorganic particles at least containing ferromagnetic particles. The thickness of the cleaning layer falls within the range of 0.05 .mu.m to 1.0 .mu.m, and the squareness ratio of the cleaning layer falls within the range of 0.6 to 0.98.

Abstract: A magnetic recording medium prepared by a process which comprises providing a nonmagnetic layer comprising a nonmagnetic powder and a binder on a nonmagnetic support, and then providing one or more magnetic layers containing at least a ferromagnetic powder and a binder on the nonmagnetic layer while the nonmagnetic layer is wet, wherein the thickness of the magnetic layer is from 0.07 to 0.20 .mu.m, the magnetic layer comprises a resin curable by a polyisocyanate as a binder, the nonmagnetic layer is a layer cured by a polyisocyanate, and the ratio N/Fe in the magnetic layer is from 0.010 to 0.090 as determined by an X-ray photoelectric spectrophotometer; and a magnetic recording medium comprising a nonmagnetic support having thereon a lower nonmagnetic layer comprising a nonmagnetic powder and a binder, and further thereon a magnetic layer comprising at least a ferromagnetic metal powder and a binder, wherein the magnetic layer has a thickness of from 0.07 to 0.20 .mu.

Abstract: A magnetic recording medium comprising a nonmagnetic substrate having thereon a magnetic layer, wherein the magnetic layer is a metal thin film comprising mainly a composition represented by the formula: (Co.sub.100-x Pd.sub.x).sub.100-y Cr.sub.y or [(Co..sub.100-x Pd.sub.x).sub.100-y Cr.sub.y ].sub.100-z O.sub.z wherein x, y and z are atomic percents, and 10.ltoreq.x 40, 5.ltoreq.y.ltoreq.25 and 0.5.ltoreq.z.ltoreq.15. The present medium can be produced at low costs, and has excellent perpendicular magnetic anisotropy.

Abstract: An optomagnetic recording medium comprising a substrate plate and, provided thereon, a recording layer and a reflection layer, said reflection layer consisting of a thin layer of an alloy of aluminum and tantalum.

Abstract: A magneto-optical recording medium has a substrate and a recording layer which is formed on the substrate. The recording layer is formed of a plurality of transition metal films and a plurality of rare earth metal films which are alternately formed one on the other, and at least a metal selected from the group consisting of Cr, Al and Ti is contained in the rare earth metal films or the transition metal films.

Abstract: An optical recording medium comprising a substrate and a metal reflective layer provided on the substrate, in which the metal reflective layer comprises an alloy of Al and at least one metal selected from the elements of Groups Ib, IIa, IVb, Vb, VIb, IIIa, IVa and Va of the Periodic Table.

Abstract: A method of making a magneto-optical recording medium comprises the step of forming a magneto-optical recording layer on a substrate by simultaneously carrying out direct current sputtering and radio-frequency sputtering. Alternatively, a magneto-optical recording layer composed of thin rare earth metal layers and thin transition metal layers overlaid alternately on a substrate is formed by carrying out radio-frequency sputtering by use of a target formed of a rare earth metal material and direct current sputtering by use of a target formed of a transition metal material.