Abstract: The present invention relates to a magnetic recording medium comprising a magnetic layer comprising a ferromagnetic powder and a binder on one surface of a nonmagnetic support and a backcoat layer comprising a granular material and a binder on the other surface of the nonmagnetic support, wherein the backcoat layer has an average surface roughness ranging from 15 to 25 nm, as measured by an atomic force microscope, and a density of protrusions equal to or greater than 50 nm in height ranges from 1 to 50/mm2 on the backcoat layer surface, as measured by a three-dimensional surface roughness meter with a contact needle. The present invention further relates to a method of reproducing magnetic signals and a magnetic signal reproduction system.

Abstract: The present invention relates to a magnetic recording medium comprising a magnetic layer comprising a ferromagnetic powder and a binder on one surface of a nonmagnetic support and a backcoat layer comprising a granular material and a binder on the other surface of the nonmagnetic support, wherein the backcoat layer has an average surface roughness ranging from 15 to 25 nm, as measured by an atomic force microscope, and a density of protrusions equal to or greater than 50 nm in height ranges from 1 to 50/mm2 on the backcoat layer surface, as measured by a three-dimensional surface roughness meter with a contact needle. The present invention further relates to a method of reproducing magnetic signals and a magnetic signal reproduction system.

Abstract: An aspect of the present invention relates to a magnetic recording medium comprising a magnetic layer comprising a ferromagnetic powder and a binder on one surface of a nonmagnetic support and a backcoat layer on the other surface of the nonmagnetic support, wherein a number of indentations equal to or greater than 20 nm in depth present on the magnetic layer surface is equal to or less than 100/10,000 ?m2, a sol component ratio in the magnetic layer is equal to or less than 5.0 percent, and the support has an amount of heat absorption based on enthalpy relaxation ranging from 0.5 J/g to 2.0 J/g, and a glass transition temperature Tg ranging from 110° C. to 140° C. The present invention further relates to a method of reproducing magnetic signals and magnetic signal reproduction system in which the magnetic recording medium is employed.

Abstract: A manufacturing method of a tape for manufacturing a curved tape curving in the width direction along the longitudinal direction of the tape, wherein, in a cutting process which cuts an original tape with a wide width into a plurality of tapes with a predetermined width by continuously passing the original tape between a rotary blade and a rotary bed knife having a receiving portion for receiving the rotary blade, an edge which has a shorter edge length between both edges in the width direction of the tape is to become a cut side by being pushed into the receiving portion of the rotary bed knife.

Abstract: A manufacturing method of a tape-form recoding medium in the present invention includes a raw web manufacturing process of forming a data recoding layer on one side of a substrate and a back coat layer having a minute convexity on the other side thereof, and thus manufacturing raw web of the tape-form recoding medium; a raw web winding process of winding the raw web with a predetermined tension; a raw web rewinding process of rewinding the raw web; and a raw web heating process of heating the rewound raw web.

Abstract: A cleaning medium for a magnetic recording apparatus is disclosed, comprising a nonmagnetic support having provided thereon a lower coating layer mainly containing a nonmagnetic inorganic powder and a binder, and a cleaning layer containing at least a ferromagnetic inorganic powder and a binder provided on the lower coating layer, wherein the thickness of the cleaning layer is from 0.05 to 1.0 ?m, the thickness of the lower coating layer is from 0.2 to 5.0 ?m, the thickness of the support is from 2.0 to 10 ?m, and the thickness in total of the cleaning medium (cleaning tape) is from 4.0 to 15 ?m.

Abstract: A magnetic tape favorably employable for recording computer data, comprising a support web, a magnetic layer and a back-coat layer and having a thickness of 3 to 10 ?m, should have a curl having a radius of curvature of greater than 10 mm in its longitudinal direction and a curl having a radius of curvature of greater than 40 mm in its width direction, wherein the curl in the width direction gives a convex surface on the side of the magnetic layer.

Abstract: A magnetic tape favorably employable for recording computer data, comprising a support web, a magnetic layer and a back-coat layer and having a thickness of 3 to 10 &mgr;m, should have a curl having a radius of curvature of greater than 10 mm in its longitudinal direction and a curl having a radius of curvature of greater than 40 mm in its width direction, wherein the curl in the width direction gives a convex surface on the side of the magnetic layer.

Abstract: A cleaning medium for a magnetic recording apparatus is disclosed, comprising a nonmagnetic support having provided thereon a lower coating layer mainly containing a nonmagnetic inorganic powder and a binder, and a cleaning layer containing at least a ferromagnetic inorganic powder and a binder provided on the lower coating layer, wherein the thickness of the cleaning layer is from 0.05 to 1.0 &mgr;m, the thickness of the lower coating layer is from 0.2 to 5.0 &mgr;m, the thickness of the support is from 2.0 to 10 &mgr;m, and the thickness in total of the cleaning medium (cleaning tape) is from 4.0 to 15 &mgr;m.

Abstract: A magnetic tape favorably employable for recording computer data, comprising a support web, a magnetic layer and a back-coat layer and having a thickness of 3 to 10 &mgr;m, should have a curl having a radius of curvature of greater than 10 mm in its longitudinal direction and a curl having a radius of curvature of greater than 40 mm in its width direction, wherein the curl in the width direction gives a convex surface on the side of the magnetic layer.

Abstract: A magnetic recording tape favorably employable for recording computer data is composed of a support, and on one side of the support, a non-magnetic layer composed of a non-magnetic powder and a binder, and a magnetic recording layer composed of a ferromagnetic powder and a binder superposed in order, and on the other side, a back-coating layer containing carbon black, in which the magnetic recording tape has a lateral thermal expansion coefficient of not more than 0.0015%/° C., a lateral humidity expansion coefficient of not more than 0.0015%/% RH, a longitudinal offset proof stress of not less than 10 N, and a longitudinal breaking strength of not less than 30 N.

Abstract: (1) A magnetic recording system is disclosed, which comprises a thin-film magnetic head and a magnetic recording medium comprising a nonmagnetic support having thereon a magnetic layer comprising mainly ferromagnetic particles and a binder resin, wherein said binder resin comprising mainly a vinyl chloride resin, and said ferromagnetic particles are surface-treated with at least an organic compound.

Abstract: A magnetic recording tape favorably employable for computer data storage has a flexible polymer web, a magnetic recording layer arranged on one surface side of the web via a non-magnetic undercoating layer, and a back-coating layer arranged on another surface side of the web, wherein the magnetic recording tape has a thickness of not more than 8 .mu.m; the non-magnetic undercoating layer has a thickness of 0.5 to 2.0 .mu.m; the magnetic recording layer has a thickness of 0.5 to 1.0 .mu.m; the polymer web has a Young's modules of not lower than 700 kg/mm.sup.2 in its width direction; and the back-coating layer is made of a binder polymer, a carbon black and an inorganic material powder.

Abstract: A magnetic recording medium comprising a non-magnetic support having thereon a magnetic layer comprising a ferromagnetic powder and a binder resin is disclosed. The magnetic layer contains a first carbon black having a DBP absorption of from 40 to 120 ml/100 g and a second carbon black having a DBP absorption of from 140 to 200 ml/100 g. Both carbon black have an average particle size of from 5 to 35 m.mu.. The medium maintains a high output level and has excellent running stability. Therefore, the dropout due to abrasion caused by an increase in friction coefficient and output reduction due to head clogging, can be avoided.

Abstract: A magnetic recording medium is described comprising a nonmagnetic support having formed thereon a magnetic layer containing a ferromagnetic powder, an abrasive, and a binder, wherein the ferromagnetic powder is a metal magnetic powder having a crystallite size of not larger than 200 .ANG., the abrasive comprises (i) an inorganic powder having a Mohs' hardness of more than 9 and a mean particle size of 0.1 to 0.9 .mu.m which is contained in an amount of from 0.1 to 10 parts by weight per 100 parts by weight of the ferromagnetic powder, and a center-line average surface roughness (Ra) of the magnetic layer is less than 5 nm. The magnetic recording medium exhibits improved properties in C/N, running durability and drop-out. A process of producing the recording medium is also disclosed involving a calender treatment with at least one pair of metal rolls.

Abstract: A magnetic recording medium in which the generation of white powder is suppressed, which recording medium maintains an appropriate running tension and exhibits a reduced level of dropouts and head clogging, comprising a non-magnetic support having thereon a magnetic layer, the magnetic layer containing a ferromagnetic powder and a binder, the ferromagnetic powder is a ferromagnetic metal powder and the magnetic layer contains a branched chain fatty acid represented by formula (I):R.sub.2 CH(CH.sub.2).sub.m COOH (I)wherein R represents CH.sub.3 (CH.sub.2).sub.n, n represents an integer of 8 or more, and m represents 0 or 1 in an amount of from 0.5 to 3 parts by weight per 100 parts by weight of said ferromagnetic metal powder.

Abstract: A magnetic recording medium comprising a non-magnetic support having thereon a magnetic layer containing a ferromagnetic powder and a binder, the non-magnetic support comprising polyethylene naphthalate in which Young's modulus in the transversal direction is at least 700 kg/mm.sup.2 and Young's modulus in the mechanical direction is less than 800 kg/mm.sup.2, the ferromagnetic powder being magnetic metal powder, and the total thickness of the magnetic recording material being not more than 11 .mu.m.

Abstract: A process for producing a magnetic recording medium is disclosed, comprising steps of (1) kneading ferromagnetic fine powders and binders with solvents, (2) optionally adding further the binders and the solvents to disperse the powders and (3) coating the resulting magnetic coating composition on a non-magnetic support, wherein the ferromagnetic fine powders have a crystallite size of not larger than 500 .ANG., the binders have at least one polar group selected from the group consisting of --SO.sub.3 M, --OSO.sub.3 M, --PO.sub.3 M.sub.2, --OPO.sub.3 M.sub.2 and --COOM (wherein M is hydrogen atom, an alkali metal or ammonium) and at least one epoxy group in the molecule and a step of adding a fatty acid having 12 to 26 carbon atoms is carried out after the dispersing step (2). Preferably, a step of crushing the ferromagnetic powders is additionally carried out before the kneading step (1).

Abstract: A magnetic recording medium comprising a non-magnetic support having provided thereon a magnetic layer containing ferromagnetic alloy particles, fine particles of metal oxides and carbon black dispersed in a binder. The ferromagnetic alloy particles have a pH of from 4.5 to 7.5. The carbon black has a pH in a range of from 6.5 to 10.5. At least one kind of fine particles of metal oxides have Mohs' hardness of 5 or higher and pH of at least 3.5 but less than 7.5 and at least one kind of fine particles of metal oxides have Mohs' hardness of 5 or higher and a pH of from 7.5 to 10.5. The binder contains a polymer having at least one kind of an acidic polar group selected from the group consisting of a phosphate group, a phosphoric acid group, a sulfonic acid group, a carboxylic acid group, a metal salt of phosphoric acid group, a metal salt of sulfonic acid group, and a metal salt of carboxylic acid group.

Abstract: A magnetic recording medium comprising a non-magnetic support having thereon a magnetic layer containing (a) ferromagnetic particles, (b) a binder containing at least one resin substituted with at least one polar group selected from an --SO.sub.3 M group, a --COOM group, an --OSO.sub.3 M group, an ##STR1## group and a ##STR2## group, wherein M represents H, Li, Na or K and M' represents H, Li, Na, K or an alkyl group, and (c) at least one fatty acid lubricating agent comprising at least one fatty acid derivative represented by formula (I): ##STR3## in which R represents a hydrocarbon group having from 11 to 21 carbon atoms, X represents hydrogen or a methyl group, R' represents a hydrocarbon group having from 1 to 8 carbon atoms and n is an integer of from 2 to 20.