Abstract: A magnetic recording medium comprising a support and a magnetic layer on said support. Said magnetic layer is a unitary magnetic layer comprising ferromagnetic metallic powder. The average grain size of said ferromagnetic powder is not more than 0.5.mu., the ratio of the major axis to the minor axis (acicular ratio) of said powders is from 1.3 to 4.5 and the coercive force of said powders is from 550 to 800 Oe.

Abstract: A magnetic recording medium comprising a support and a magnetic layer on said support. The magnetic layer is a unitary magnetic layer comprising ferromagnetic metallic powder. The average grain size of said ferromagnetic powder is not more than 0.5.mu., the ratio of the major axis to the minor axis (acicular ratio) of said powders is from 1.3 to 4.5, and the coercive force of said powder is from 1350 Oe to 1600 Oe.

Abstract: A magnetic recording medium is described, comprising a non-magnetic support having provided thereon a magnetic layer comprising ferromagnetic particles dispersed in a binder, said ferromagnetic particles having a BET specific surface area of 25 m.sup.2 /g or more, said binder comprising a modified polyurethane resin containing 0.1 meq/g or more of functional groups selected from carboxyl groups, hydroxyl groups, sulfonic acid groups, and epoxy groups, and containing at least three functional groups per molecule of the resin.

Abstract: A magnetic recording medium is disclosed which is comprised of a support base having positioned thereon a magnetic layer having a ferromagnetic powder dispersed in a binder composition. The binder composition is comprised of a vinyl chloride-vinyl alcohol copolymer in an amount of 40 wt % to about 95 wt %. The copolymer contains 1 wt % to less than 8 wt % of vinyl alcohol component and 0 to 2 wt % of vinyl acetate component. By using the binder composition which includes the copolymer the resulting magnetic recording medium have excellent surface smoothness, good dispersion of ferromagnetic powder, excellent electromagnetic properties, as well as excellent running property and durability.

Abstract: A composition containing CrO.sub.2 and a polyester-polyurethane wherein the chain extender contains a mixture of 1,4-butanediol and 1,6-hexanediol; and use thereof, especially in magnetic recording media.

Abstract: Magnetic recording media comprise a non-magnetic base which is provided with a magnetic layer consisting of finely divided anisotropic magnetic material which is dispersible in binders and additives, the binder being a mixture of (1) an OH-containing polyurethane which is crosslinked with polyisocyanates, (2) a high molecular weight thermoplastic linear polyurethane and (3) a polyvinylformal binder, a phenoxy resin, a cellulose ester or a vinyl chloride copolymer.

Abstract: Magnetic recording media comprise a non-magnetic base which is provided with a magnetic layer which consists of a dispersion of an anisotropic magnetic material in an organic binder which consists essentially of an OH-containing polyurea-urethane binder crosslinked with polyisocyanate. The OH-containing polyurea-urethane is obtained by reacting a polydiol, a diol and a primary or secondary aminoalcohol, and if appropriate a triol, with a diisocyanate.

Abstract: Magnetic recording media comprising a non-magnetic base which is provided with a magnetic layer which consists essentially of a dispersion of an anisotropic magnetic material in a mixture of an OH-containing polyurea-urethane binder, which is crosslinked with a polyisocyanate, with a physically drying binder.

Abstract: Magnetic recording media comprise a non-magnetic base which is provided with a magnetic layer consisting of finely divided anisotropic magnetic material which is dispersible in binders and additives, the binder being a mixture of (1) a high molecular weight thermoplastic linear polyurethane, (2) a polyvinylformal binder, a phenoxy resin, a cellulose ester or a vinyl chloride copolymer and (3) an OH-containing polyurethane which is crosslinked with polyisocyanates.

Abstract: A magnetic recording medium including a magnetic layer formed on a plastic base and having perpendicular magnetic anisotropy suited for perpendicular magnetization, has a back coating formed on the rear side of the base opposite the magnetic side. The back coating is a thermoset coating cured from a thermosetting composition or a radiation-cured coating cured from radiation-curable composition containing at least one component having at least one acrylic, maleic, or allylic double bond. The back coating has an asperity in the range of 0.04 to 0.6 .mu.m. By suitably selecting the asperity the running quality and output profile are improved.

Abstract: The composition and method of making a magnetic recording media using a polyurethane binder system with high lubricant retention and a high concentration of magnetic particles is described. The use of hydrated alumina with a solvent blocked isocyanate is used to produce an open cell microporosity in the cured coating wherein the individual voids are not greater than the magnetic bit cell size and the alumina particles remain in the coating to improve abrasion resistance. The porosity size is controlled by a surface active agent additive. Also shown is the method of preparing hydrated alumina with small particle size, dispersibility, and compatibility, and wherein the dehydrating temperature has the same range as the isocyanate deblocking temperature whereby the CO.sub.2 formation that creates the porosity occurs as the polyurethane components cure.

Abstract: A magnetic recording medium having a magnetic layer formed by a thin film deposition method, characterized in that the magnetic layer contains Fe as the principal component, Co, Ni and at least one of Mn, Cu, V, Nb, Ta, Mo, W, Ti, Zr and Hf.

Abstract: A magnetic recording medium comprises a non-magnetic substrate, a thin magnetic metal film layer overlaid on the substrate, a metallic oxide layer formed on the surface of the thin magnetic metal film layer, and a polymer film formed by plasma polymerization. The polymer film is overlaid on the metallic oxide layer to improve the corrosion resistance and durability of the magnetic recording medium.

Abstract: A magnetic recording medium having a Mn-Al recording layer containing at least one of Fe, Co, and Ni and having an easy magnetization axis in the perpendicular direction to the layer. The magnetic recording layer can be formed at a high speed by employing magnetron sputtering.

Abstract: A magnetic recording medium comprising a support and provided thereon a magnetic layer containing magnetic powder and a copolymer capable of being soluble in water by 10 parts by weight or more per 100 parts by weight of water.Further, a process of preparing a magnetic recording medium wherein magnetic powder is treated with a copolymer capable of dissolving 10 parts by weight or more per 100 parts by weight of water in an aqueous medium under presence of a metal ion and a magnetic paint containing this treated magnetic powder is coated on base to form a magnetic layer is also provided.

Abstract: A magnetic recording medium comprising fine ferromagnetic particles as the main component and a binder composed of a mixture of a radiation sensitive soft resin, a radiation sensitive modified resin and a partially saponified vinyl chloride-vinyl acetate copolymer containing at least 0.5% by weight of maleic acid, said binder being cross-linked and polymerized by radiation.

Abstract: A magnetic recording medium comprising a support having coated thereon a magnetic layer is disclosed. The magnetic layer is comprised of a binder composition having ferromagnetic particles dispersed therein. The binder composition is cured by an electron beam and comprises a copolymer, a urethane resin and a compound having two or more acryloyl groups or methacryloyl groups. The copolymer may be a vinyl chloride-vinyl acetate-vinyl alcohol copolymer having a vinyl alcohol content of 1 to 15 wt % or a vinyl chloride-vinyl acetate-maleic acid copolymer having a maleic acid content of 1 to 10 wt %. The recording medium has excellent electromagnetic properties and the magnetic layer has excellent dynamic properties.

Abstract: A magnetic recording medium, produced by preparing a resin solution for magnetic paint having as a main component thereof a copolymer of (A) vinyl chloride, (B) a vinyl carboxylate, (C) an unsaturated carboxylic acid and (D) an unsaturated carboxylic anhydride, containing 50 to 80% by weight of (A) based on the total of the amounts of (A) and (B), 60 to 90% by weight of (D) based on the total of the amounts of (C) and (D), and 1 to 5 parts by weight of the total of (C) and (D) based on 100 parts by weight of the total of (A) and (B) and having an average polymerization degree of 100 to 400, mixing 10 to 80% by weight of said resin solution weigh 90 to 20% by weight of a radiation-sensitive curing resin, blending the resultant mixture as a main component with a magnetic powder, applying the resultant magnetic paint to a non-magnetic substrate, and solidifying the applied layer of paint with radiation.

Abstract: By inclusion of a fluorinated graphite material in conjunction with a silicone oil in the magnetic layer of a magnetic recording medium, the medium is improved significantly in its smooth-running properties and electromagnetic performance properties.

Abstract: The magnetic recording medium of this invention contains in the binder a modified polymer prepared by graft-polymerizing a nitrogen-containing polymerizable unsaturated compound onto a polymer by irradiating with radiation to modify the polymer.The modified polymer used in this invention is produced by the graft-copolymerization utilizing the irradiation of radiation, the applicable range of polymers used for producing the modified polymer is wide and, thereby providing a large industrial value. Also, since the modified polymer used in this invention has a nitrogen-containing side chain, the modified polymer contributes to improve the dispersibility and packing properties of a magnetic powder in the magnetic layer. Accordingly, a magnetic recording medium having excellent magnetic characteristics and durability can be provided by this invention.

Abstract: The tape running property of a magnetic recording medium is improved by provision a back layer. This magnetic recording medium comprises a magnetic layer on one side of a non-magnetic support and a back layer on the other side thereof, in which the magnetic layer consists mainly of a ferromagnetic metal powder and a binder and has a coercive force of at least 1000 Oe and a surface roughness of at most 0.03 .mu.m, the ferromagnetic metal powder having a specific surface area of at least 35 m.sup.2 /gr and a saturation magnetization of at least 120 emu/gr, while the back layer has a surface electric resistance of at most 1.times.10.sup.10 .OMEGA. and a surface roughness of at most 0.05 .mu.m.

Abstract: Described herein is a magnetic recording medium comprising a substrate and a magnetic recording layer thereon comprising a cured binder and magnetic particles, the binder containing a blend of a thermoplastic polymer or polymers and a polyfunctional acrylate derivatives of a caprolactone-polyol or a polyester polyol.

Abstract: A magnetic recording medium is described, comprising a non-magnetic support base having positioned thereon a magnetic layer and optionally a non-magnetic layer, wherein at least one layer of the magnetic and non-magnetic layers contains an ester derived from pentaerythritol and/or its condensate and a fatty acid and/or a resin acid. This recording medium has superior surface properties and can be satisfactorily used in tape decks.

Abstract: A magnetic recording material is disclosed which is comprised of a single magnetic layer comprised of plate-shaped ferromagnetic particles wherein the plate-shaped ferromagnetic particles are present in greater number in the surface part of the magnetic layer than in the inner part and/or the plate-shaped ferromagnetic particles are aligned such that an average horizontal axis component of the particles with respect to the surface of magnetic layer is larger in the surface part than in the inner part. The location and alignment of the particles make is possible to increase output with short-wave recording.

Abstract: A magnetic recording material comprised of a non-magnetic support base having provided thereon a magnetic recording layer on one side and the back layer on the other side is disclosed. The magnetic recording layer is comprised of ferromagnetic particles dispersed in a binder in combination with carbon black particles having an average primary particle size of 30 .mu.m or less. The back layer is comprised of a binder having dispersed therein carbon black having an average primary particle size in the range of 50 to 150 m.mu.. The magnetic recording material has improved electromagnetic properties and improved durability, particularly with respect to video S/N and dropout.

Abstract: Magnetic recording media are described which are characterized by a recording layer formed on at least one side of a support and made of magnetic particles and a TiO powder dispersed throughout a resin binder. The TiO powder is used in an amount of 0.1 to 35 wt % of the magnetic particles and has an average size of about 0.015 to 5 microns.

Abstract: A magnetic recording medium which comprises a plastic base film and a magnetic layer formed on one side of the base film and composed of a ferromagnetic alloy powder dispersed in a resin binder, characterized in that said ferromagnetic alloy powder has a surface area of at least 48 m.sup.2 /g measured by BET method, said magnetic layer has a coercive force of at least 1,000 Oe and a surface roughness of at most 0.08 .mu.m, and a radiation-cured backing layer made of a radiation sensitive resin and having a surface roughness of from 0.05 to 0.6 .mu.m is formed on the other side of the base film.

Abstract: A heat curable magnetic coating mixture contains one or more polymeric additives selected to thermally oxidize during coating cure to create a plurality of microvoids in the cured coating as an aid to increase the retention of a lubricant which is applied to the cured coating.

Abstract: A magnetic recording medium has a biaxially-oriented polyester film base which includes carbon black beads having a median diameter from 50 to 500 nm and is substantially free from beads or agglomerates more than 5 micrometers in diameter. The beads provide opacity such as is often required of the flexible recording disk of a diskette. The film base may be either a single layer, throughout which the beads are uniformly dispersed, or it may be multi-layer, e.g., a central layer containing the carbon black beads and two surface layers which are free from the beads.

Abstract: A magnetic recording medium is disclosed. The medium is comprised of a non-magnetic support having coated thereon a magnetic recording layer and a backing layer on the surface opposite the magnetic recording layer. The backing layer contains carbon black and the surface treated calcium carbonate dispersed in a binder. The calcium carbonate is surface treated so as to make the particles hydrophobic. Including the carbon black and the calcium carbonate in the backing layer provides a recording medium with improved durability and a reduced amount of drop out.

Abstract: Disclosed is a magnetic recording medium which comprises magnetic particles; a phosphate represented by the formula: ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 may be the same or different and each represent R.sup.4 O--CH.sub.2 O--.sub.n (wherein R.sup.4 is an alkyl group having 8 to 20 carbon atoms or an alkylphenyl group whose alkyl group moiety has 8 to 20 carbon atoms, and n is an integer of 2 to 10) or a group of HO--, with the proviso that at least one of R.sup.1, R.sup.2 and R.sup.3 is a group of R.sup.4 O--CH.sub.2 CH.sub.2 O--.sub.n (wherein R.sup.4 and n are as defined above); a lecithin; and a binder.

Abstract: A magnetic recording medium is disclosed which includes a non-magnetic substrate, a first layer made of bismuth formed on the substrate in a discontinuous island shape, and a ferromagnetic metal layer formed over the first layer and the substrates and also a magnetic recording medium is disclosed which includes a non-magnetic substrate, a first layer formed continuously covering the substrate made of amorphous silicon and/or silicon compound, a second layer made of bismuth formed on the substrate in a discontinuous island shape and a ferromagnetic metal layer formed over the first and second layers.

Abstract: A magnetic recording medium such as magnetic tape or magnetic disc is disclosed in which a magnetic layer if formed on the non-magnetic base material and in which the fatty acid ester with diglycerol is contained as the lubricant.The fatty acid ester with diglycerol employed as the lubricant is an ester of diglycerol with a saturated or unsaturated fatty acid with 8 to 22 carbon atoms.

Abstract: A magnetic recording medium having a non-magnetic substrate, a bismuth layer of less than 100 .ANG. thick formed on one major surface of the non-magnetic substrate and a magnetic metal thin film formed on the bismuth layer.

Abstract: A magnetic recording medium comprised of a nonmagnetic support base having a magnetic layer provided thereon is disclosed. The magnetic layer includes ferromagnetic particles dispersed in a binder in combination with carbon black particles. The carbon black particles have an average primary particle size in the range of 30 m.mu. to 50 m.mu.. Further, the carbon black is capable of the adsorption of 120 ml or more of dibutyl phthalate per 100 g of carbon black. By utilizing the particular carbon black of the present invention it is possible to obtain a magnetic recording medium having improved running properties.

Abstract: A magnetic recording medium for use in video and other applications is presented which comprises a substrate, a continuous thin magnetic layer of cobalt and at least one selected from nickel, chromium, and oxygen, preferably obliquely evaporated on the substrate, and a topcoat formed over the magnetic layer and made of a phosphate compound having the formula: ##STR1## where R is selected from alkyl radicals having 10 to 22 carbon atoms, and Y and Y' are independently selected from the group consisting of hydrogen atom, alkyl radicals and monovalent cations, and Y and Y' may together represent a divalent cation.

Abstract: A magnetic recording medium is described comprising a non-magnetic support layer, a magnetic layer and at least one layer of a high-molecular weight boron containing compound of the formula: ##STR1##

Abstract: A magnetic recording medium which comprises a non-magnetic support having thereon a magnetic recording layer containing ferromagnetic metal particles and a binder, wherein the ferromagnetic metal particles have a specfic area of about 35 to about 80 m.sup.2 /g, and the magnetic recording layer has a surface roughness of about 0.001 to 0.04 .mu.m and a residual amount of the solvent is about 0.5 to about 30 mg/m.sup.2.

Abstract: A magnetic recording medium comprises a non-magnetic substrate and at least one layer of obliquely deposited magnetic crystals which contains, as a main constituent, Co or a Co--Ni based alloy containing Cr in an amount within the range of 2 to 8 atom % and has a density of 5.0 g/cm.sup.3 or more, said layer being formed on said non-magnetic substrate.

Abstract: A magnetic recording coating has a high density of magnetic particles uniformly dispersed in a thermoset resin binder with the dispersion applied as a thin coating onto a rigid substrate. The thermoset resin binder comprises a phenolic, an epoxy, and a styrene allylalcohol. The curing action of this coating is initiated by blocked acid catalysts. The material can be cured at a low temperature to produce a smooth, hard coating with an improved orientation ratio and without impairing the properties of the magnetic particles.

Abstract: A magnetic recording medium comprising a substrate, a magnetic layer formed on the substrate and comprising a metallic magnetic material as a recording element and a protective layer formed on the magnetic layer and comprising a perfluroalkyl polyether derivative having a phosphate terminal group, which has improved durability and corrosion resistivity.

Abstract: A magnetic recording medium comprises a substrate and a thin magnetic metal layer formed on the substrate by a sputtering method and composed essentially of Mn, Al and Cu.

Abstract: Magnetic recording media which comprise a support, a magnetic recording layer on one side of the support, and a non-magnetic layer comprising TiO on the other side are described. The non-magnetic layer is made of a dispersion of TiO particles in a resin binder or is a continuous vacuum-deposited TiO layer.

Abstract: Magnetic recording member having a magnetic storage layer covered by composite overlaying layers including an intermediate layer and a lubricant layer. The thin intermediate layer is formed by coating an aminosilane or epoxysilane compound directly or indirectly over the magnetic layer. The lubricant layer is formed over the intermediate layer by coating a lubricant made of a fluorinated hydrocarbon polymer having a terminal carboxyl or sulfonic acid group. The lubricant layer is chemically coupled with the intermediate layer by reacting the terminal carboxy or sulfonic acid group with the aminosilane or epoxysilane compound of the lubricant layer at room temperature or by heating, whereby the lubricant layer is stabilized to suppress deterioration of the lubricant layer and to suppress the reduction in lubricating property due to dispersion.

Abstract: A magnetic recording medium has, on a nonmagnetic support, a magnetic layer consisting mainly of an acicular iron oxide magnetic powder and a binder. In order to improve the S/N ratio, a fine magnetic powder having a specific surface area as determined by the BET method, of not less than 35 m.sup.2 /g is used. In order to improve the dispersibility of the magnetic powder and to improve the squareness ratio and durability thereof, the binder contains a resin which has a molecular weight of not more than 50,000 and has at least one polar group selected from the group consisting of polar groups having the general formulas: ##STR1## (wherein M is hydrogen, lithium, sodium or potassium; and M.sub.1 and M.sub.2 are hydrogen, lithium, sodium, potassium or alkyl groups.

Abstract: A magnetic recording medium produced by forming an organic protective layer on a magnetic recording layer by sputtering conducted in an inert gas atmosphere using a material for forming the organic protective layer as cathode and the magnetic recording layer as anode has excellent lubricating properties and wear resistance.

Abstract: A magnetic recording medium includes a substrate, a magnetic layer and a subbing layer therebetween. The subbing layer includes tin oxide type powders having a mean particle size not higher than 0.8 micron. S/N ratio is improved.

Abstract: Magnetic recording media which comprise a non-magnetic support and a magnetic layer formed on at least one side thereof, in which the magnetic layer is made of a magnetic composition which comprises magnetic particles dispersed throughout a resin binder consisting essentially of a reaction product of a fluorine resin having at least two hydroxyl groups in one molecule of the resin and a curing polymer material having functional groups capable of reaction with the fluorine resin through the at least two hydroxyl groups.

Abstract: A magnetic recording medium protected by a very thin, composite low surface energy covering is disclosed. The covering comprises a primer layer of a polymerized phosphorylated monomer or oligomer and an outer lubricant layer of perfluoropolyether polymer. The two layers may be polymerized in situ. The primer layer is made from monomers such as phosphorylated bis[4-methacryloyloxyhydroxypropylcarbamato-cyclohexyl]methane. The outer layer is made from a polymerizable perfluoropolyether monomer such as ##STR1## The composite low surface energy covering is especially useful for providing lubricity and corrosion resistance to a metallic thin-film magnetic recording coating.

Abstract: This invention provides a magnetic recording medium with excellent electromagnetic characteristics and running durability. According to the invention, a magnetic powder is kneaded with a cross-linkable or polymerizable resin binder, together with a phosphoric ester having a polymerizable, unsaturated double bond or bonds, the resulting coating material is applied to a substrate, and then the coating is cross-linked or polymerized. The addition of the phosphoric ester in place of an ordinary dispersing agent improves the mechanical properties of the magnetic coating and the durability and running quality of the magnetic recording medium.