Abstract: In a magnetic recording medium comprising a magnetic recording layer on the surface of a non-magnetic support member, a ferromagnetic powder, an abrasive having a Mohs' hardness of at least 6, colloidal silica and a fatty acid and fatty acid ester are incorporated in the magnetic layer, thus improving the durability of the magnetic layer and decreasing the head abrasion.

Abstract: A magnetic recording medium is composed of a base and a magnetic coating which comprises a binder and a magnetic powder dispersed therein. The magnetic powder, in turn, contains a nonmagnetic powder having an average particle size of not more than 2 .mu.m and a hardness of at least 6 on Mohs scale, in an amount of 1-20% on the basis of the weight of the magnetic powder, and the binder contains a resin such as polyester resin having a group expressed by the formula --SO.sub.3 M where M is monovalent metal such as Na.

Abstract: A magnetic recording medium comprises a substrate coated with a magnetic composition comprising a cobalt adsorbed iron oxide powder with a phosphoric ester type anionic surfactant at a ratio of 2 wt. % or more and a binder at a ratio of said iron oxide powder to said binder of 4 or more.A magnetic recording medium has a coercive force Hc of 950 to 1200 Oe and a residual magnetic flux .phi..sub.r of 0.35 to 0.6 maxwell.

Abstract: A magnetic recording medium and a process for producing it is disclosed. The medium is comprised of a non-magnetic flexible support base and a magnetic layer formed on a surface of the support base. The magnetic layer is preferably in the form of a thin, ferromagnetic metal film formed by vapor deposition. An overcoat layer of a fluorine-containing organic material is formed directly on the magnetic layer. The fluorine content of the overcoat layer continuously and gradually decreases in the direction toward the magnetic layer. Accordingly, high fluorine content near the surface of the overcoat layer provides improved smoothness near the surface whereas the lower fluorine content near the interface of the overcoat with the magnetic layer allows for strong adhesion between the overcoat and the underlying magnetic layer substrate.

Abstract: A magnetic recording medium comprises a thin metallic magnetic layer on a non-magnetic substrate wherein said thin metallic magnetic layer is made of cobalt, nickel and chromium.

Abstract: A magnetic recording medium is provided which has smooth and stable running performances and is free of "squeal" phenomenon, especially in an environment of high temperature and high humidity. A highly viscous silicone oil having a viscosity of 100,000 centistokes or more is incorporated in combination with a higher fatty acid ester composed of a higher fatty having a melting point of 44.degree. C. or more and a monohydric alcohol containing 3 to 8 carbon atoms into a magnetic coating layer of the magnetic recording medium. Such silicone oil is represented by the general formula: ##STR1## wherein R is CH.sub.3, R' is CH.sub.3, C.sub.6 H.sub.5 or F and n is a number which determines a viscosity thereof. Such higher fatty acid ester is selected from butyl myristate, butyl palmitate, propyl stearate, butyl stearate and the like.

Abstract: A magnetic recording medium is provided which has smooth and stable running performances and is free of "squeal" phenomenon, especially in an environment of high temperature and high humidity. A highly viscous silicone oil having a viscosity of 100,000 centistokes or more is incorporated in combination with a higher fatty acid glycerine ester composed of a higher fatty acid having a melting point of 44.degree. C. or more and glycerine into a magnetic coating layer of the magnetic recording medium. Such silicone oil is represented by the general formula: ##STR1## wherein R is CH.sub.3, R' is CH.sub.3, C.sub.6 H.sub.5 or F and n is a number which determines a viscosity thereof. Such higher fatty glycerine ester is selected from monoglyceride of myristic acid, monoglyceride of palmitic acid, monoglyceride of stearic acid, monoglyceride of oleic acid and the like.

Abstract: A magnetic recording medium which comprises a substrate coated with a magnetic paint which has a magnetic powder dispersed in a binder comprising a vinyl chloride - vinyl acetate copolymer containing at least 10% of polyvinyl alcohol, a urethane resin and a polyester resin.

Abstract: A magnetic recording medium comprised of a nonmagnetic base and a magnetic coating layer thereon, said magnetic coating layer comprises ferromagnetic particles dispersed in a binder vehicle, characterized in that said magnetic coating layer contains a glyceride and a sorbitan ester of fatty acid.

Abstract: The present invention relates to an improved magnetic recording medium comprising a magnetic recording layer on the surface of a non-magnetic support, in which the magnetic recording layer contains a fatty acid, high viscosity silicone oil and fatty acid ester.

Abstract: A magnetic recording medium having a base, a first magnetic layer formed on the base, and a second magnetic layer formed on the first magnetic layer. The magnetic recording medium further comprises a third magnetic layer which does not contain a binder formed on the second magnetic layer. A third magnetic layer containing a binder has a predetermined thickness to cover surface roughness of the second magnetic layer and functions as a protection layer for the second magnetic layer.

Abstract: A magnetic recording medium is described comprising a non-magnetic support having formed thereon a magnetic layer comprising a binder and fine ferromagnetic particles dispersed therein, said binder containing a polyester polyurethane prepared by reacting poly(1,6-hexane adipate) with 4,4'-diphenylmethane diisocyanate.

Abstract: A magnetic recording medium is provided which has smooth and stable running performances and is free of "squeal" phenomenon, especially in an environment of high temperature and high humidity. A highly viscous silicone oil having a viscosity of 100,000 centistokes or more is incorporated in combination with a sorbitan fatty acid ester into a magnetic coating layer of the magnetic recording medium. Such silicone oil is represented by the general formula: ##STR1## wherein R is CH.sub.3, R' is CH.sub.3, C.sub.6 H.sub.5 or F and n is a number which determines a viscosity thereof. Such sorbitan fatty acid ester is selected from sorbitan monopalmitate, sorbitan monostearate, sorbitan distearate, sorbitan tristearate, sorbitan monooleate and the like.

Abstract: A magnetic recording medium is described comprising a first layer comprising a magnetic iron oxide powder dispersed in a binder formed on a nonmagnetic support, a second layer formed on the first layer comprising a ferromagnetic metal powder dispersed in a binder, and having a greater coercive force than the first layer, and a third layer comprising a thin ferromagnetic metal film formed on the second layer in a thickness of from 0.01.mu. to 0.5.mu..

Abstract: A magnetic recording medium comprising a nonmagnetic flexible base and a magnetic recording layer formed thereon which is mainly composed of fine ferromagnetic particles and a binder. The binder contains both a vinyl chloride/vinyl acetate/vinyl alcohol copolymer and a vinyl chloride/vinylidene chloride copolymer.

Abstract: A magnetic recording medium is disclosed comprising a non-magnetic base bearing a magnetic layer mainly consisting of ferromagnetic particles and a binder wherein the magnetic layer contains a polymer having a polar functional group and a degree of polymerization of not more than 100.

Abstract: A magnetic recording medium having a substrate coated with a magnetic layer comprises a magnetic powder and a binder, essentially consisting of 40 to 80 wt. % of a polyester resin, 60 to 20 wt. % of a nitrocellulose impregnated with vinyl chloride-vinyl acetate copolymer as a protective component and a polyisocyanate.

Abstract: Magnetic recording medium protected by an ultra-thin, composite low surface energy covering provided by an inner layer of insoluble polymer and an outer layer of insoluble polymer which are made by in situ polymerization. The inner layer is made from two monomers such as a hydantoin hexacrylate and alpha-methyl styrene. The outer layer is made from polymerizable perfluoropolyether monomer having ethylenicaly unsaturated polymerizable groups. The composite low surface energy covering is especially useful for providing lubricity and corrosion resistance to a metallic thin-film magnetic recording coating.

Abstract: A magnetic recording medium comprises a substrate coated with a magnetic layer comprising a magnetic powder and a binder comprising an urethane resin and a vinyl chloride-vinyl acetate-maleic acid copolymer having a content of maleic acid component of at least 1.5%.

Abstract: A magnetic recording medium comprises a substrate coated with a magnetic layer comprising a magnetic powder and a first non-magnetic powder of Al.sub.2 O.sub.3 and/or Cr.sub.2 O.sub.3 at a ratio of 0.5 to 15 wt. % based on said magnetic powder; a second non-magnetic powder of TiO.sub.2, SiC, SiO.sub.2, ZrO.sub.2 and/or CeO.sub.2 at a ratio of 0.5 to 15 wt. % based on said magnetic powder and a total of said non-magnetic powders of less than 20 wt. % based on said magnetic powder.

Abstract: A magnetic disk coating composition contains magnetic particles and a binder system comprising epoxy and phenolic resins, a titanate coupling agent and a water miscible solvent system, the coating having a pigment volume concentration of up to 35.

Abstract: A magnetic recording medium comprising a non-magnetic base which has formed thereon a magnetic layer made of a binder and fine ferromagnetic particles dispersed therein is disclosed. The magnetic layer is characterized by containing a mineral oil having a viscosity of 300 cs or less at 37.8.degree. C. and an aliphatic acid having 12 to 22 carbon atoms.

Abstract: A magnetic recording medium comprises a substrate coated with a magnetic powder composition comprising a magnetic powder and an organic binder having a main component of vinyl chloride-vinyl alcohol copolymer.

Abstract: A thin metallic layer type magnetic recording medium having thin metallic layers in a structure comprises a layer in which a tilt angle of a metallic particle direction to the normal line to said substrate gradually increases depending upon an increase of a distance from said substrate; and a layer in which a tilt angle of a metallic particle direction to the normal line to said substrate gradually decreases depending upon an increase of a distance from said substrate.

Abstract: A magnetic recording medium comprising a coated magnetic recording layer having video and chroma S/N ratios appropriately balanced with tape transporting characteristics is attained by controlling the magnetic layer to have a surface roughness such that the maximum value of the arithmetical average roughness (Ra) is about 80 A or greater in the surface roughness pitch region greater than about 300 .mu.m while in the surface roughness pitch region of about 5 .mu.m to about 100 .mu.m the maximum value of the arithmetical average roughness (Ra) is about 40 A or less.

Abstract: A recording medium and, more particularly, a recording medium based on a composition exhibiting high dispersibility for finely-divided ferromagnetic powders having excellent abrasion resistance is disclosed in which the magnetic composition comprises a finely-divided ferromagnetic powders dispersed in a binder containing 2-chloroacrylonitrile polymer and a polyurethane prepolymer; in another embodiment of the invention the magnetic composition additionally contains a polyisocyanate compound.

Abstract: A magnetic thin film deposited on a non-magnetic substrate consists substantially of Ni, Co and oxygen, the content of Ni being between 10 and 55% by weight based on the weight of Ni and Co, the atomic percent ratio of oxygen to Ni and Co being between 3 and 45%.

Abstract: An improved magnetic record member having a nonmagnetic disk base with a mirrored surface, a magnetic-metal thin-film medium formed on the disk base; an intermediate layer composed of an oxide of a magnetic metal, a chromium oxide, or a phosphate formed on the film medium; and a layer of polysilicate or a metal alcoxide hydrolysis polymer formed on the intermediate layer.

Abstract: A magnetic recording medium which comprises a base material and a magnetic layer provided on its surface, said magnetic layer comprising metallic magnetic particles, a binder and a salt of lanolin fatty acid wherein the oxidation resistance of the metallic magnetic particles is highly improved and the metallic magnetic particles are in a good dispersion state so that the magnetic recording medium shows an increased maximum magnetic flux density is disclosed.

Abstract: A magnetic material of amorphous iron-nitride and a method for preparing the same are provided.

Abstract: A magnetic recording tape comprising a non-magnetic support having thereon a dual layer magnetic recording coating comprising ferromagnetic particles dispersed in a binder, wherein the fine ferromagnetic particles of the outer layer are a mixture of two or more kinds of fine ferromagnetic particles having two or more peaks in the coercive force distribution and said particles containing at least one kind of fine ferromagnetic alloy particles and the fine ferromagnetic particles of the inner layer being ferromagnetic iron oxide particles having peaks in the coercive force distribution lower than the minimum peaks in the coercive force distribution of the ferromagnetic particles of the outer layer, with the thickness of the outer layer not being greater than the thickness of the inner layer.

Abstract: In a storage system including a semi-permanent database there is provided apparatus for updating said database comprising: instrumentalities for reading magnetically recorded data and storing said data in said database; a rotatable drum having an exterior circumferentially-extending surface, said drum including a plurality of protrusions extending beyond said exterior surface; a flexible magnetic card including database updating data magnetically recorded on a major surface thereof, said card having opposed side edges extending lengthwise thereof and having a leading edge and a trailing end edge respectively extending transverse to the length thereof, the length of said card being such that one of said end edges is disposable in overlapping relationship with respect to the other of said end edges when said card is wrapped around said drum, said card having a plurality of apertures formed therein, said apertures located to permit registration of a sufficient number of said apertures with said drum protrusions

Abstract: A magnetic recording element made in accordance with the present invention comprises a layer of magnetic material applied to a carrier formed from a material of high magnetic permeability. A layer of non-ferrous, non-magnetic material is interposed between the carrier and the layer of magnetic material. The layer of non-magnetic material has a thickness between 20 and 40 microns. The magnetic recording element enables sharply defined magnetized domains to be obtained and is in a simple and repeatable fashion, by using a process in which the materials applied to the carrier of the element undergo no chemical transformation. To this end, the non-magnetic layer is produced by successively depositing, on the carrier which is used as a cathode, a first layer of copper obtained from an alkaline electrolytic solution, and then a second layer of copper which is obtained from an acid electrolytic solution.

Abstract: A magnetic recording medium comprising a nonmagnetic support having thereon a magnetic recording layer of a ferromagnetic powder dispersed in a binder, wherein the ferromagnetic powder is a low vacuum evaporation process ferromagnetic metal powder subjected to a surface oxidation stabilizing processing and the low vacuum evaporation process ferromagnetic metal powder is one processed with an aqueous solution containing at least one anionic surface active agent.

Abstract: This invention relates to a magnetic recording medium which comprises a non-magnetic support, at least one magnetic recording layer containing a magnetic powder and a binder and being provided on the support and a ferromagnetic metal thin film with a thickness of at most 1 micron, being provided on the magnetic recording layer by an oblique incidence vapor deposition method with an electric field. This multi-layer magnetic recording medium exhibits various excellent magnetic recording performances.

Abstract: In a magnetic recording member comprising a non-magnetic support having provided thereon a magnetic layer comprising finely divided ferromagnetic powders dispersed in a binder, in which the binder comprises about 10 to about 70 wt% of (a) a polyester-polyurethane resin and about 30 to about 90 wt% of (b) a synthetic non-drying oil modified alkyd resin and (c) a polyisocyanate, wherein the molar ratio of the isocyanate groups present in the polyisocyanate (c) to the hydroxyl groups present in the synthetic non-drying oil-modified alkyd resin (b) ranges from about 0.8:1 to about 2.0:1. The binder system in accordance with the present invention provides excellent magnetic properties, particularly improved squareness ratio and 5 MHz output. The binder system of the present invention also enables the use of finely divided ferromagnetic alloy powders, with excellent magnetic properties being maintained when magnetic recording members are produced therefrom.

Abstract: A magnetic record member for use in magnetic recording devices is disclosed. The record member comprises a non-magnetic alloy disk polished to a mirror surface, a non-magnetic alloy layer formed on the disk, a magnetic thin film medium formed on the surface of the alloy layer, and a protective polysilicate film layer formed on the alloy layer. In certain embodiments, an oriented lubricant layer is formed on the polysilicate film layer.

Abstract: A selectable-fraction of revolution tape recorder for reproducing short recorded sounds such as brief words or greetings like "thank you". The recorded sound is recorded in a magnetic sound recording tape or material provided on an outside peripheral surface of a cylindrical part which extends downwardly from the edge of a rotating disc. A pair of switches is provided, one of which is responsive to means carried by the disc and the other of which is physically actuable whereby to initiate and for a predetermined period of time to continue the rotation of the disc. A plurality of switching paths is provided on the disc with recesses extending for different fractional portions of the perimeter of the respective switching path so that appropriate fractions of a revolution of the tape recorder can be selected by selecting an appropriate switching path.