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 is disclosed, comprising a non-magnetic support having provided thereon at least a lower non-magnetic layer comprising a binder having dispersed therein a non-magnetic powder and an upper magnetic layer comprising a binder having dispersed therein a ferromagnetic powder which has been coated on said lower non-magnetic layer while the lower non-magnetic layer is wet, wherein the upper magnetic layer has an average dry thickness (d) of not more than 1.0 .mu.m and an average thickness variation (.sup..DELTA. d) at the interface between the upper magnetic layer and lower non-magnetic layer is not more than d/2. The magnetic recording medium exhibits excellent electromagnetic characteristics, running properties, and durability.

Abstract: A magnetic recording medium is disclosed, comprising a non-magnetic support having provided thereon at least a lower non-magnetic layer comprising a binder having dispersed therein a non-magnetic powder and an upper magnetic layer comprising a binder having dispersed therein a ferromagnetic powder which has been coated on said lower non-magnetic layer while the lower non-magnetic layer is wet, wherein the upper magnetic layer has an average dry thickness (d) of not more than 1.0 .mu.m and an average thickness variation (.sup..DELTA. d) at the interface between the upper magnetic layer and lower non-magnetic layer is not more than d/2. The magnetic recording medium exhibits excellent electromagnetic characteristics, running properties, and durability.

Abstract: A magnetic recording medium is disclosed, comprising a non-magnetic support having provided thereon at least a lower non-magnetic layer comprising a binder having dispersed therein a non-magnetic powder and an upper magnetic layer comprising a binder having dispersed therein a ferromagnetic powder which has been coated on said lower non-magnetic layer while the lower non-magnetic layer is wet, wherein the upper magnetic layer has an average dry thickness (d) of not more than 1.0 .mu.m and an average thickness variation (.sup..DELTA. d) at the interface between the upper magnetic layer and lower non-magnetic layer is not more than d/2. The magnetic recording medium exhibits excellent electromagnetic characteristics, running properties, and durability.

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 is disclosed, comprising a non-magnetic support having provided thereon at least a lower non-magnetic layer comprising a binder having dispersed therein a non-magnetic powder and an upper magnetic layer comprising a binder having dispersed therein a ferromagnetic powder which has been coated on said lower non-magnetic layer while the lower non-magnetic layer is wet, wherein the upper magnetic layer has an average dry thickness (d) of not more than 1.0 .mu.m and an average thickness variation (.sup..DELTA. d) at the interface between the upper magnetic layer and lower non-magnetic layer is not more than d/2. The magnetic recording medium exhibits excellent electromagnetic characteristics, running properties, and durability.

Abstract: A magnetic recording medium is disclosed, comprising a non-magnetic support having provided thereon at least a lower non-magnetic layer comprising a binder having dispersed therein a non-magnetic powder and an upper magnetic layer comprising a binder having dispersed therein a ferromagnetic powder which has been coated on said lower non-magnetic layer while the lower non-magnetic layer is wet, wherein the upper magnetic layer has an average dry thickness (d) of not more than 1.0 .mu.m and an average thickness variation (.sup..DELTA. d) at the interface between the upper magnetic layer and lower non-magnetic layer is not more than d/2. The magnetic recording medium exhibits excellent electromagnetic characteristics, running properties, and durability.

Abstract: A magnetic recording medium is disclosed, comprising a non-magnetic support having provided thereon at least a lower non-magnetic layer comprising a binder having dispersed therein a non-magnetic powder and an upper magnetic layer comprising a binder having dispersed therein a ferromagnetic powder which has been coated on said lower non-magnetic layer while the lower non-magnetic layer is wet, wherein the upper magnetic layer has an average dry thickness (d) of not more than 1.0 .mu.m and an average thickness variation (.sup..DELTA. d) at the interface between the upper magnetic layer and lower non-magnetic layer is not more than d/2. The magnetic recording medium exhibits excellent electromagnetic characteristics, running properties, and durability.

Abstract: A magnetic recording medium is disclosed, comprising a nonmagnetic support having provided thereon at least a lower nonmagnetic layer comprising a binder having dispersed therein a non-magnetic powder and an upper magnetic layer comprising a binder having dispersed therein a ferromagnetic powder which has been coated on said lower non-magnetic layer while the lower non-magnetic layer is wet, wherein the upper magnetic layer has an average dry thickness (d) of not more than 1.0 .mu.m and an average thickness variation (.sup..DELTA. d) at the interface between the upper magnetic layer and lower non-magnetic layer is not more than d/2. The magnetic recording medium exhibits excellent electromagnetic characteristics, running properties, and durability.

Abstract: A magnetic recording medium is disclosed, comprising a non-magnetic support having provided thereon at least a lower non-magnetic layer comprising a binder having dispersed therein a non-magnetic powder and an upper magnetic layer comprising a binder having dispersed therein a ferromagnetic powder which has been coated on said lower non-magnetic layer while the lower non-magnetic layer is wet, wherein the upper magnetic layer has an average dry thickness (d) of not more than 1.0 .mu.m and an average thickness variation (.sup..DELTA. d) at the interface between the upper magnetic layer and lower non-magnetic layer is not more than d/2. The magnetic recording medium exhibits excellent electromagnetic characteristics, running properties, and durability.

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.

Abstract: A magnetic recording medium containing a support having thereon in order, a non-magnetic layer unit and a magnetic layer unit, said magnetic recording medium having been produced by providing a non-magnetic layer unit containing at least one non-magnetic layer and comprising a non-magnetic powder dispersed in a binder on a non-magnetic support followed by providing, while the non-magnetic layer is still wet, a magnetic layer unit containing at least one magnetic layer and comprising a ferromagnetic powder dispersed in a binder on the non-magnetic layer, wherein the mean thickness of the magnetic layer is 1.0 .mu.m or less and the non-magnetic powder in the non-magnetic layer comprises (A) a tabular non-magnetic powder having a tabular size of from 0.01 to 0.3 .mu.m and an aspect ratio of from 3 to 20, or an acicular non-magnetic powder having a long axis of from 0.05 to 0.25 .mu.m and an aspect ratio of from 3 to 15, (B) a carbon black powder having a mean particle size of from 0.01 to 0.04 .mu.

Abstract: A magnetic recording medium is disclosed comprising a non-magnetic support having provided thereon at least a lower non-magnetic layer comprising a binder having dispersed therein a non-magnetic powder and an upper magnetic layer comprising a binder having dispersed therein a ferromagnetic powder which has been coated on said lower non-magnetic layer while the lower non-magnetic layer is wet, wherein the upper magnetic layer has an average dry thickness (d) of not more than 1.0 .mu.m and an average thickness variation (.sup..DELTA. d) at the interface between the upper magnetic layer and lower non-magnetic layer is not more than d/2. The magnetic recording medium exhibits excellent electromagnetic characteristics, running properties, and durability.

Abstract: Disclosed is a magnetic recording medium comprising at least two layers comprising at least one lower non-magnetic layer containing at least a non-magnetic particle and a binder on a non-magnetic support, and at least one upper magnetic layer containing at least a ferromagnetic particle and a binder on the lower non-magnetic layer, wherein a mean total thickness d of the upper magnetic layer is more than 0.01 .mu.m to less than 0.3 .mu.m, and a standard deviation .sigma. of the total thickness of the upper magnetic layer and the mean total thickness d of the upper magnetic layer satisfy the relationship of 0.05.ltoreq..sigma./d.ltoreq.0.5.

Abstract: Disclosed is a magnetic recording medium comprising a nonmagnetic support, a lower nonmagnetic layer and an upper magnetic layer. The lower nonmagnetic layer is coated on the support, comprises an inorganic nonmagnetic powder dispersed in a binder, and is surface-coated with an inorganic oxide. The upper magnetic layer has a dry thickness of 1.0 micrometers or less and comprises a dispersion of a ferromagnetic powder in a binder. The upper magnetic layer is coated onto the lower nonmagnetic layer.

Abstract: A magnetic recording medium produced by providing a lower non-magnetic layer comprising a non-magnetic powder dispersed in a binder on a non-magnetic support followed by providing, while the lower non-magnetic layer is still wet, an upper magnetic layer comprising a ferromagnetic powder dispersed in a binder on the lower non-magnetic layer, wherein a mean thickness of the upper magnetic layer is 1.0 .mu.m or less and the non-magnetic powder in the lower non-magnetic layer comprises (A) a granular inorganic powder having a mean particle size of from 0.01 to 0.08 .mu.m, (B) a carbon black powder having a mean particle size of from 0.01 to 0.04 .mu.m and (C) a powder component having a larger mean particle size than the mean particle size of each of powders (A) and (B). The magnetic recording medium has good electromagnetic characteristics and has excellent running durability with little edge damage after repeated running.

Abstract: Disclosed is a magnetic recording medium, comprising (a) a nonmagnetic flexible support, (b) a lower nonmagnetic layer provided on the support and comprising a nonmagnetic particle and a binder, and (c) a magnetic layer provided on the nonmagnetic layer and comprising a ferromagnetic particle and a binder, wherein (i) the magnetic layer comprises at least two layers comprising a lower magnetic layer provided on the lower nonmagnetic layer and an upper magnetic layer provided on the lower magnetic layer, (ii) a ratio of the lower nonmagnetic layer thickness to the total magnetic layer thickness of the lower magnetic layer and the upper magnetic layer is from 1 to 50, (iii) the upper magnetic layer and the lower magnetic layer have a difference in coercive force of at least 80 Oe, and (iv) the lower nonmagnetic layer and at least the lower magnetic layer are formed by a wet-on-wet coating method.

Abstract: A magnetic recording medium is disclosed, comprising a nonmagnetic support having thereon a lower nonmagnetic layer comprising nonmagnetic particles dispersed in a binder and further having on the lower layer an upper magnetic layer comprising ferromagnetic metal particles comprising alpha iron crystals dispersed in a binder, wherein said upper magnetic layer has diffraction dots attributable to the ferromagnetic metal particles present on the magnetic layer surface when analyzed by reflection high-energy electron diffraction, the number of said diffraction dots is from 5 to 15 when counted in a 100.degree. range on a circular arc of diffraction dots caused by diffraction on a (211) plane of said ferromagnetic metal particles present on the magnetic layer surface.

Abstract: A magnetic recording medium excellent in electromagnetic properties is disclosed, which comprises a non-magnetic support and at least two magnetic layers formed thereon, each of which is mainly composed of a magnetic substance and a binder, in which a first magnetic layer (a lower layer) has a coercive force of 450 to 660 Oe, a residual magnetic flux density (Br) of 1,950 gausses or more and a thickness of 1.5 to 5 .mu.m, a second magnetic layer (an upper layer) has a coercive force of 700 to 900 Oe, a residual magnetic flux density of 1,500 gausses or more and a thickness of 1.5 to 3 .mu.m, the difference in coercive force between the first magnetic layer and the second magnetic layer is 150 to less than 300 Oe, the difference in residual magnetic flux density between the first magnetic layer and the second magnetic layer is within 600 gausses, and the total thickness of magnetic layers on the non-magnetic support is 3 to 7 .mu.m.

Abstract: A magnetic recording medium comprising a nonmagnetic support and at least two magnetic layers on the support, each magnetic layer containing a ferromagnetic powder and a binder, wherein the lower magnetic layer comprises at least one layer containing a branched fatty acid-modified silicone, but not carbon black, and the upper magnetic layer comprises at least one layer containing a branched fatty acid-modified silicone and carbon black having a DBP absorption oil amount of 100 to 250 ml/100 g. The magnetic recording medium has improved lubricating characteristics.