Abstract: A magnetic recording medium having a high durability with good electro-magnetic properties, which comprises a base material and a magnetic layer provided thereon, the magnetic layer containing magnetic particles and a binder, characterized in that the magnetic layer further comprises alpha-Fe.sub.2 O.sub.3 particles, Al.sub.2 O.sub.3 particles and Cr.sub.2 O.sub.3 particles.

Abstract: A magnetic thin film comprised of at least one, usually two magnetic metals selected from iron, nickel, and cobalt is vapor phase grown on a substrate, for example, polyimide film by introducing chemical compounds of the metals in vapor form, a reducing gas, and optionally, an oxidizing gas, into a vacuum chamber where the substrate is placed and preferably heated to a temperature of at least 100.degree. C., and subjecting the reaction gases to plasma excitation, thereby achieving the vapor phase growth of the magnetic thin film on the substrate.

Abstract: A novel magnetic recording medium comprising a non-magnetic support, a magnetic recording layer, and an intermediate layer containing an electroconductive polymer. An optional second intermediate layer contains carbon black and is provided on either surface of the first intermediate layer. The magnetic recording medium has low surface electric resistance, and when used as a video tape, has both a high video S/N ratio and improved stability of video S/N with the passage of time.

Abstract: A magnetic recording medium comprises a magnetic coating material, or a dispersion of magnetic particles in a resinous binder, and a base to which the coating material is solidly applied, the resinous binder comprising as its ingredients a copolymer composed of vinyl chloride, vinylidene chloride, a vinyl alkylcarboxylate, another monomer copolymerizable with vinyl chloride, and a saponified vinyl alkylcarboxylate and having an OH/CH absorption ratio according to the infrared absorption spectrum of at least 0.2, a polyurethane resin having in its molecule a --SO.sub.3 M group wherein M represents an alkali metal atom, and a polyisocyanate.

Abstract: A magnetic recording medium comprising a non-magnetic resin support, and a magnetic layer form on the support. A polyester or polyurethane resin undercoat is formed between the support and the magnetic layer in the form of islands which are isolated from one another.

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 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 as measured by BDT 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 thermoset backing layer having a surface roughness of from 0.05 to 0.6 .mu.m is formed on the other side of the base film, the backing layer being made of a thermosetting resin composition comprising a vinyl chloride-vinyl acetate-vinyl alcohol copolymer, a polyurethane resin and a polyisocyanate.

Abstract: A magnetic recording medium has on a nonmagnetic support, a magnetic layer consisting mainly of an acicular magnetic powder and a binder. The medium has excellent magnetic characteristics required for short-wave recording and has an excellent durability. For this purpose, the medium contains a ferromagnetic metal powder which has a coercive force of not less than 1,000 Oe and a specific surface area as determined by the BET method, of not less that 45 m.sup.2 /g. The medium contains in the binder not less than 50% by weight of a resin which has a high dispersibility owing to the introduction of at least one polar group selected from the group consisting of polar groups having the general formulas of: ##STR1## (wherein M is hydrogen, lithium, sodium or potassium; and M.sub.1 and M.sub.2 are hydrogen, lithium, sodium, potassium or alky groups).

Abstract: A magnetic recording media containing a normally liquid polyphosphazene lubricant, e.g. low molecular weight linear or cyclic poly-fluoroalkoxy phosphazene mixtures.

Abstract: This invention relates to a magnetic recording medium whose coefficient of friction is lowered without lowering S/N and which has an improved running property, which comprises a magnetic recording layer on one side of a nonmagnetic support and a back layer containing an inorganic powder and a binder and having a thickness of at most 2.mu., on the other side thereof, characterized in that the surface of the back layer is provided with surface projections with a height of 0.05 to 0.8.mu., an interval of at least 50.mu. and 50 to 50,000 projections/cm.sup.2.

Abstract: A magnetic recording medium is disclosed, in which a magnetic layer is formed on one surface of the non-magnetizable substrate and a back coating layer consisting essentially of a binder and a non-magnetizable pigment is formed on the other surface of the substrate. In the back coating layer, more than 80 weight percent of the binder is a polyurethane resin or a polyester resin having hydrophilic polar groups. The back coating layer also contains carbon black for preventing electrostatic charging and pigments with Mohs hardness higher than 5 for improving durability. The carbon black to the pigments weight ratio is set to be in the range of 95:5 to 60:40.

Abstract: A magnetic recording medium comprises a magnetic layer coated on a substrate and composed of ferromagnetic powder dispersed in a binder, wherein the magnetic layer contains TiO.sub.2 having an average particle size of at most 8 .mu.m and a surface area of at most 25 m.sup.2 /g as measured by a nitrogen adsorption method, and Al.sub.2 O.sub.3 having an average particle size of at least 0.1 .mu.m and a surface area of at most 30 m.sup.2 /g as measured by a nitrogen adsorption method.

Abstract: A perpendicular magnetic recording medium composed of a base material, a 1st magnetic thin layer formed on the base material, and a perpendicularly magnetizable 2nd magnetic thin layer formed on the 1st magnetic thin layer, wherein the 1st magnetic thin layer is composed of a Co-base ternary amorphous alloy containing small amounts of Hf and Ta.

Abstract: A magnetic recording medium comprising a resinous component in which magnetic particles are dispersed and a base to which the dispersion is solidly applied, the resinous component consisting of a copolymer having an OH/CH absorption ratio according to the infrared absorption spectrum of 0.2 or more and made from (A) vinyl chloride, (B) vinylidene chloride, (C) a vinyl alkylcarboxylate, (D) an other monomer copolymerizable with vinyl chloride, and (E) a saponified vinyl alkylcarboxylate, and a rubbery binder. Alternatively, a polyisocyanate is added to the above copolymer.

Abstract: Disclosed is a magnetic recording medium comprised of a substrate and a layer of magnetic powder coated on a surface of the substrate, characterized in that the magnetic powder is hexagonal crystals having single domain crystalline magnetic anisotropy, particle sizes of 0.01 to 0.3 .mu.m, particle size/thickness ratios of 2.3 to 15 and the tapping packing rate of said magnetic powder is 15% or more.

Abstract: A magnetic recording medium comprising a support having coated thereon a magnetic recording layer containing a ferromagnetic powder dispersed in a binder and a vinyl chloride-vinyl acetate copolymer having a degree of polymerization from about 10 to 100 and at least one terminal carboxyl group. The magnetic recording medium contains the above copolymer in an amount of from about 0.1 to 10 wt % based on the amount of ferromagnetic powder, and preferably also contains a conventional binder. This magnetic recording medium provides both video and audio magnetic tapes having superior running properties, durability and electromagnetic properties.

Abstract: A magnetic recording medium, produced by preparing a resin solution for magnetic paint containing a mixture of a radiation curable resin modified copolymer of (A) vinyl chloride, (B) a vinyl carboxylate, (C) vinyl alcohol, (D) an unsaturated carboxylic acid and (E) an unsaturated carboxylic anhydride, containing 50 to 90% by weight of (A) based on the total of the amounts of (A), (B) and (C), 0 to 30% by weight of (E) based on the total of the amounts of (D) and (E), and 1 to 5 parts by weight of the total of (D) and (E) based on 100 parts by weight of the total of (A), (B) and (C) and having an average polymerization degree of 100 to 400 and an other radiation curable resin, and a magnetic powder, applying the resultant magnetic paint to a nonmagnetic substrate, and curing the applied layer of paint with radiation.

Abstract: A magnetic recording medium comprising a non-magnetic support and a magnetic recording layer formed on at least one side of the support, the magnetic recording layer being made of a cured mixture of magnetic particles and an organosilica gel bearing isopropyl end groups dispersed in thermosetting resin binders.

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, (D) an unsaturated carboxylic anhydride and (E) vinyl alcohol, containing 50 to 90% by weight of (A) based on the total of the amounts of (A), (B) and (E), 1 to 15% by weight of (E) based on the total of the amounts of (A), (B) and (E), 0 to 30% by weight of (D) based on the total of 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), (B) and (E) and having an average polymerization degree of 100 to 400, mixing 10 to 80% by weight of said resin solution with 90 to 20% by weight of a radiation curable resin, blending the resultant mixture as a main component with a magnetic powder, applying the resultant magnetic paint to a non-magnetic substrate, and curing the applied layer of paint with radiation.

Abstract: A manufacturing method for a magnetic recording medium is disclosed which comprises the steps of forming a metallic magnetic layer on a non-magnetic substrate such as a polyester film with or without a non-magnetic metal layer deposited thereon by a method of electroless plating or electroplating, forming a vapor-phase plasma-polymerized layer of a silane compound, e.g. 1,1,2,2-tetramethyl disilane and 1,1,2,2,3,3-hexamethyl trisilane, and forming a thin layer of a fluorocarbon resin. The thus manufactured magnetic recording medium has advantages in several properties such as the surface lubricity sufficient to give satisfactory smoothness of travelling, durability in abrasion resistance and weatherability.

Abstract: A magnetic recording medium is disclosed which comprises a non-magnetic support having provided thereon a magnetic recording layer consisting ferromagnetic powder and containing graphite and a fatty acid ester.

Abstract: A magnetic recording medium is disclosed, which comprises a non-magnetic support having, on opposite surfaces thereof, a magnetic recording layer containing magnetic particles and a backing layer containing carbon black and other inorganic particles and a binder having a thickness of not more than 2.mu., the backing layer containing (a) carbon black having an average particle size of 60 to 120 m.mu. and (b) other inorganic particles having an average particle size of 20 to 100 m.mu..

Abstract: A magnetic recording medium is coated, over its magnetic layer, with a thin film of a siloxane-linkage-containing polymer. The magnetic layer consists of a thin film formed by vacuum evaporation or sputtering or by dispersion of a ferromagnetic metal powder in a binder. The polymer having the siloxane linkage is prepared by polymerizing an organo-silicon compound which either inherently possesses the linkage or is capable of producing it. The polymerization is preferably effected by the plasma polymerization technique.

Abstract: In a magnetic recording medium comprising a length of a non-magnetic plastic substrate and a magnetic thin layer of Co or Co-Ni or Co-Ni-Cr formed thereon, when the coercive force of the medium is measured by changing the measuring direction in a plane defined by a longitudinal direction of the substrate and a direction normal to the major surface of the substrate, the following relationship is met:(Hc.sub.max -Hc.sub.min)/Hc(0).ltoreq.0.9where Hc.sub.max is the maximum coercive force, Hc.sub.min is the minimum coercive force, and Hc(0) is a coercive force in the longitudinal direction of the substrate.

Abstract: A magnetic recording medium is disclosed. The medium comprises a non-magnetic support having provided on opposite surfaces a magnetic recording layer and a backing layer containing two types of carbon black and a binder and having a thickness of 2 .mu.m or less, one of said carbon black being fine carbon black having an average particle size of 30 to 100 m.mu. and the other of said carbon black being coarse carbon black having an average particle size of 150 to 500 m.mu., and the mixing weight ratio of said carbon black and the binder being 1:1.5 to 1:3.5.

Abstract: In a magnetic recording medium comprising a non-magnetic substrate and a magnetic layer of Co or Co-Ni in the form of a continuous thin film on the substrate, the magnetic layer has oxygen-rich sub-layers at its surfaces adjacent to and remote from the substrate. The oxygen-rich sub-layers are produced by injecting energy particles containing oxygen to the surface of the substrate during the initial and final stages of formation of the magnetic layer.

Abstract: A magnetic recording medium comprising a transparent plastic film substrate, a primer coating layer formed on the substrate and a magnetic layer for magnetic recording formed on the primer coating layer, wherein said primer coating layer is formed by dispersing carbon black in a radiation curable coating material composed essentially of at least one oligomer or polymer containing at least one radiation curable unsaturated double bond per molecule and curing the resulting dispersion by radiation.

Abstract: An improved lubricant system for magnetic recording media such as helical scan video tapes is disclosed. The resulting improved magnetic recording media comprise the usual flexible or rigid backing and a magnetizable layer on the backing, but the lubricant is comprised of an organic compound selected from the group consisting of isomeric carboxylic acids and isomeric alcohols (e.g. iso-stearic acid and iso-stearyl alcohol). A fatty acid ester may be included in the lubricant.A typical composition utilizes 0.5 parts by weight iso-stearic acid per 100 parts of magnetizable material (e.g., cobalt doped ferric oxide particles) and 1 part by weight of isopropyl palmitate per 100 parts of the magnetizable material. Video tapes lubricated with this new system, have shown improved electromagnetic output (e.g., higher signal-to-noise ratios). In addition, they are able to withstand the stop motion of a helical scan video head better than prior known lubricant systems.

Abstract: A magnetic recording medium comprising a non-magnetic support, a magnetic layer on a surface of the non-magnetic support, and a backing layer on a reverse surface of the non-magnetic support, composed of powder and a binder, and having a thickness of not more that 2 microns, wherein said powder comprises TiO.sub.2 powder and carbon black powder in the weight ratio of 4:6 to 10:0. The average particle size of TiO.sub.2 powder ranges from 0.01 to 0.8 microns.

Abstract: A magnetic recording medium comprising a non-magnetic substrate, a magnetic recording layer formed on one side of the substrate and a back coating layer on the other side of the substrate, characterized in that the back coating layer is a coating composed essentially of carbon black, a resin binder and a lubricant, the weight ratio of the carbon black to the binder being from 1:1 to 1:4, and the carbon black having a particle size of from 10 to less than 100 m.mu.m.

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 consisting of a monoalkylamine in which the alkyl contains 10 to 22 carbon atoms.

Abstract: A magnetic recording medium comprising a plastic base film, a magnetic layer formed on one side of the base film and composed of a ferromagnetic alloy powder dispersed in a resin binder, and a backing layer formed on the other side of the base film, characterized in that said ferromagnetic alloy powder has a surface area of at least 48 m.sup.2 /g as 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 said backing layer is composed essentially of a thermoset or radiation-cured resin and carbon black dispersed in the resin, and has a surface roughness of from 0.05 to 0.6 .mu.m, said carbon black having an average particle size of from 10 to 60 .mu.m as measured by an electron microscope.

Abstract: An oriented polyester film is provided according to the present invention which contains, per 100 parts by weight of a polyester,(A) 0.005-2 parts by weight of fine particles having average size of 0.05-3 .mu.m, and(B) 0.005-2 parts by weight of at least one compound selected from the group consisting of high aliphatic monocarboxylic acids having 10-33 carbon atoms and esters thereof.Herein also disclosed is a composite polyester film which comprises a resin layer of copolyester or copolyester ether containing an ester-forming alkali metal salt of sulfonic acid compound, the layer being laminated on at least one side of the oriented polyester film as a substrate. The present invention further provides a magnetic recording medium comprising the oriented polyester film or the composite polyester film as a base.The novel films of the present invention have a surface satisfying three properties: flatness, slipperiness and adhesion, which are considered unable to be attained with a conventional polyester film.

Abstract: A magnetic recording medium comprising a nonmagnetic support having coated thereon a magnetic recording layer comprising a ferromagnetic particles dispersed in a binder, the binder containing polyisocyanate and the molar ratio of (urethane bond+allophanate bond):(urea bond+biuret bond) being 85:15 to 60:40.

Abstract: A magnetic recording medium comprising a plastic base film, a thin magnetic metal layer formed on one side of the base film and a backing layer formed on the other side of the base film, characterized in that the backing layer is composed essentially of a thermoset or radiation-cured resin and carbon black dispersed in the resin, and has a surface roughness of from 0.05 to 0.4 .mu.m, said carbon black having an average particle size of from 10 to 60 m.mu.m as measured by an electron microscope.

Abstract: Layered coherent structures characterized by periodic, alternating layers of cobalt and palladium and/or platinum exhibit perpendicular magnetic anistropy.

Abstract: A magnetic recording member characterized in that a magnetic film formed on a surface of a substrate has a very small amount of hydrogen mixed therein. The manufacturing process therefor is characterized in that hydrogen gas is introduced into the vacuum treatment chamber while the magnetic particles are adhered to the surface of the substrate.

Abstract: Described is a magnetic recording medium comprising a substrate and a magnetic recording layer therein comprising a binder and magnetic particles, the binder comprising a lactone-acrylate adduct.

Abstract: A magnetic recording medium is disclosed comprising a substrate coated with a mixture which consists essentially of (1) hexagonal plate-like shaped, ferrite magnetic powder particles having an average particle diameter of 0.2 .mu.m or less and (2) a binder resin having an active hydrogen equivalent of 2000 or more. This magnetic recording medium displays no flocculation of the hexagonal system ferrite magnetic powder, and has excellent dispersion properties and perpendicular orientation ability. Further, smoothness on the coating film is good, and S/N properties are noticeably improved.

Abstract: When an abrasive having an oleophilic surface used in a magnetic recording medium obtained by subjecting an inorganic powder having a Mohs hardness of 5 or above and an average particle size of 2 .mu.m across or below to a dry contact treatment with a dispersing agent having an oleophilic group under grinding conditions giving an impact value of 1 G or greater is used in combination with a magnetic powder as a magnetic recording layer of magnetic recording medium, the wear at a magnetic head can be prevented and still characteristics can be improved.

Abstract: A magnetic recording medium which comprises a non-magnetic support having on the surface side thereof a magnetic recording layer and on the opposite side thereof a backing layer having a thickness of 2 .mu.m or less, which contains carbon black and a binder and optionally, an inorganic powder, in which the backing layer contains at least two kinds of carbon black, one being fine-grained carbon black having a mean grain size of 10 to 30 m.mu. and the other being coarse-grained carbon black having a mean grain size of 150 to 500 m.mu. such that the weight ratio (P/B) of the total amount of carbon black and inorganic powder (P) to binder (B) is from about 1/0.5 to 1/3.5. The recording medium described provided smooth and stable tape-running for an extended period and a high S/N ratio.

Abstract: A magnetic recording medium comprising a support having provided thereon a magnetic recording layer containing (1) a cobalt-containing iron oxide, (2) graphite, and (3) a copolymer of vinyl chloride, vinyl acetate and maleic acid.

Abstract: A magnetic recording medium having a magnetic layer which is formed by dispersing a magnetic powder and further an abrasive when necessary into a binder containing a sugar alcohol. The magnetic recording medium has excellent glossiness, squareness ratio and other surface properties due to the improvement of dispersibility of the magnetic powder and/or an abrasive when necessary.

Abstract: Weather resistance and lubricity of a magnetic recording medium comprising a non-magnetic support having provided thereon a vapor deposited magnetic thin film mainly composed of cobalt, nickel and oxygen can be improved by limiting the amount of nickel and the number of oxygen atoms to a specific value and by providing a plasma polymerized layer on the magnetic thin film.

Abstract: Magnetic recording media consist of a non-magnetic base and a magnetic layer firmly bonded thereto, the magnetic layer containing further additives in addition to ferromagnetic metal powder, an organic binder, a metal oxide powder and conventional assistants.

Abstract: A magnetic recording medium is disclosed which comprises a non-magnetic support, having a Young's modulus of 7.times.10.sup.10 to 1.times.10.sup.13 dyn/cm.sup.2, having coated on opposite surfaces, a magnetic recording layer comprising ferromagnetic particles and a fatty acid ester and a backing layer comprising a cellulose resin.

Abstract: A magnetic recording medium having deposited on the surface of a non-magnetic substrate a magnetic layer formed by dispersing a powdered magnetic substance and a powdered abrasive in a binder, which magnetic recording medium is characterized by having abrasive particles activated on the surface thereof.

Abstract: A magnetic recording medium is disclosed which comprises a non-magnetic support having provided on opposite surface thereof a magnetic recording layer, and a backing layer containing carbon black and a binder, said carbon having an average particle size of not less than 150 m.mu. and the weight ratio of carbon black and the binder being 1:3.0 to 1:10.

Abstract: There is provided a magnetic recording material which comprises a support and a magnetic layer coated thereon. The magnetic layer contains as its binder, a combination of at least one vinyl chloride-vinyl acetate-based copolymer characterized by its --CO.sub.2 H content or cellulose dinitrate, at least one urethane acrylate having a particular chemical structure, and at least one low molecular weight compound having two or more acryloyl or methacryloyl groups. The magnetic layer is hardened by beam irradiation. Thus, marked increase in dispersibility of ferromagnetic powders, improvement in electromagnetic transformation characteristics and sharp increase in durability are attained.

Abstract: A composition which is useful for preparing a magnetic recording medium is prepared by homogeneously mixing components comprising a magnetic powder, a resin binder and a partial hydrolyzate of an organosilicon compound which contains at least two silicon-bonded hydrolyzable groups and at least one carbon-bonded amino group. When conventionally applied to a substrate to provide the magnetic recording media, the compositions of this invention provide a magnetic layer which is more durably attached to the substrate. Improved magnetic recording media, such as magnetic tapes, are thereby provided.

Abstract: In a magnetic recording medium comprising a plastic base film and a magnetic layer formed thereon, the base film is plasma treated at frequencies in the range of 10 kHz to 200 kHz in an inorganic gas such as argon and nitrogen and preferably, in an inorganic gas containing at least 5% of oxygen.