Abstract: A magnetic recording medium having a magnetic layer on one surface of a non-magnetic base and having as required a backcoat layer on the other surface, having at least one of p-tolyldiiodemethylsulfone, 2,3,3-triiodoallyl alcohol and 2-methoxycarbonylaminobenzimidazole and 2-methoxycarbonylaminobenzimidazolium salt as an anti-fungus agent on or in the magnetic layer and/or the backcoat layer.

Abstract: The present invention makes it possible that in a magnetic recording medium having a magnetic layer which contains therein ferromagnetic powder and serving as a magnetic recording medium for short wavelength recording in, for example, a video tape recorder, when the coercive force of the magnetic layer is over 1000 Oe, the specific surface area of its ferromagnetic alloy powder measured according to BET adsorption method is made 45 m.sup.2 /g or above, and the high density recording where the central recording wavelength is not more than 1 .mu.m is carried out thus recording and playback with low noise and high output being made.

Abstract: A magnetic recording medium comprised of a non-magnetic substrate and a magnetic layer formed on one surface of the substrate and consisting essentially of a binder and magnetic powders. As the binder, a thermoplastic polyurethane-urea resin is employed, in which hydrophilic polar groups are introduced. The thermoplastic polyurethane-urea resin contains urethane and urea bonds in the molecule thereof and may be synthesized from a long-chain diol with a molecular weight of about 500 to 5000, a short-chain diol with a molecular weight of about 50 to 500, an organic diisocyanate and an organic diamine.

Abstract: A magnetic recording medium has a magnetic layer consisting essentially of a binder and magnetic particles on one surface of a non-magnetic substrate. The thermoplastic polyurethane-urea resin in which unsaturated bonds sensitive to radiation are introduced is used as the binder.The thermoplastic polyurethane-urea resin in which the radiation-sensitive unsaturated bonds are introduced has both urethane and urea bonds in the molecular structure thereof. It is synthesized from long chain diol with a molecular weight of approximately 500 to 5000, a short chain diol with a molecular weight of approximately 50 to 500, an organic diisocyanate, an organic diamine, and a compound containing radiation-sensitive unsaturated double bonds, and cured by radiation.The thermoplastic polyurethane-urea resin in which not only the radiation-sensitive double bonds but also hydrophilic polar groups are introduced may also be used as the binder. These hydrophilic polar groups may for example include --SO.sub.3 M, --OSO.sub.

Abstract: The magnetic recording medium comprises a non-magnetic substrate and a magnetic layer formed thereon composed mainly of magnetic powder and a binder. The binder contains a binder component having an absorbed amount of the binder component to a surface of the magnetic powder more than 1.5 mg per square meter of a surface area of the powder measured in 3 weight % solution in methyl ethyl ketone solvent, and the magnetic layer has a pigment volume concentration of the magnetic powder between 60 and 75%.The binder provides an improved strength and high pigment volume concentration of magnetic coating layer, and improved durability of the magnetic recording medium.

Abstract: A method for manufacturing a magnetic recording medium of the invention, comprises the steps of coating a magnetic paint consisting mainly of a needle-like magnetic powder and a binder on a nonmagnetic support to form a coating film; applying a DC magnetic field of a predetermined direction obtained with a superconductive solenoid magnet to the coating film in which the needle-like magnetic powder is still mobile, thereby orienting the needle-like magnetic powder in the predetermined direction; and drying the coating film.In a magnetic tape prepared by this method, a residual magnetic flux density is improved by about 10 to about 20% over the conventional tape, and tape the sensitivity and output are significantly improved. Since only a permanent current need be flown through a superconductive wire having a substantially zero electric resistance, power loss due to heat generation may be eliminated.

Abstract: The electron radiation curable resin of this invention is an oligopolyester-urethane resin having urethane bonds at both terminals of a polyester moiety, or a polyester-polyurethane resin wherein polyester moieties are chain-extended through urethane bonds. The resin has a molecular weight of about 1,000 to 50,000, and has a double bond at each terminal of the molecule and contains in the molecure about 0.2 to 30 mol % of carboxylic acid component having a metal sulfonate group based on the total carboxylic acid component.This electron radiation curable resin is suitable as a binder for a magnetic paint for producing magnetic recording medium such as magnetic tape, and can provide a magnetic recording medium having excellent dispersibility, durability, and solvent resistance.

Abstract: Improved magnetic media comprising a non-magnetic substrate and a magnetic layer formed on at least one side of the substrate. The magnetic recording media are provided in a variety of ways with a specific type of organosilane compound serving as a lubricant and represented by the following general formula: ##STR1## where R is a saturated or unsaturated monovalent hydrocarbon residue having from 7 to 21 carbon atoms, n is 0, 1 or 2, and p is an integer from 1 to 12. The organosilane lubricant compound may be incorporated in the magnetic layer itself, in a back coating layer, or it may constitute a layer on the magnetic layer or on the back coating layer.

Abstract: The magnetic recording medium contains the magnetic layer comprising the magnetic or magnetizable powders or particles and the binder comprising a composition containing(A) a compound represented by formula (V): ##STR1## (wherein R is methyl or ethyl group and X is a group containing an acrylic or methacrylic double bond; i is a number in the range of approximately 200 to 800, j is a number in the range of approximately 10 to 200, k is a number in the range up to approximately 200, and l is a number in the range of approximately 3 to 100, provided that the division of l by the sum of k and l is in the range from approximately 0.2 to 1.0)and(B) a compound having at least two acrylic and/or methacrylic double bonds in the molecule thereof and having a molecular weight ranging from approximately 1,000 to 6,000 in which the molecular weight in the molecule per one double bond is in the range from approximately 80 to 3,000.

Abstract: A magnetic recording medium having a magnetic layer which is cured by irradiating radiation onto the magnetic layer in which magnetic or magnetizable powder material surface-treated with a silicon compound having a silanol group and/or a silanol-forming group upon hydrolysis and a double-bond sensitive to radiation irradiated is present with a binder. The magnetic recording medium having the aforesaid structure has a sufficient durability.

Abstract: A magnetic recording medium having a layer containing as a lubricant one or more organo-polysiloxane compounds having the following formula (I): ##STR1## (wherein R.sub.1 is a divalent hydrocarbon residue having 1 to 5 carbon atoms; R.sub.2 is a monovalent hydrocarbon residue having from 7 to 21 carbon atoms; R.sub.3 and R.sub.4 may be the same or different and are --CH.sub.3, --(CH.sub.2).sub.2 (CF.sub.2).sub.k CF.sub.3 or --R.sub.1 SCOR.sub.2 ; k is 0 or an integer ranging from 1 to 12; each of l, m and n is independently 0 or an integer ranging from 1 to 200 and the sum of 1+m+n is up to 300, with the proviso that when at least one of R.sub.3 and R.sub.4 is the group --R.sub.1 SCOR.sub.2, each of l, m and n may be 0 and that when at least one of R.sub.3 and R.sub.4 is a group other than the group --R.sub.1 SCOR.sub.2, each of l and m may be 0 but n is an integer ranging from 1 to 200).

Abstract: The thermoplastic polyurethane resin having a molecular weight larger than about 5,000 is obtainable by the polyaddition of a long chain diol (A) having a molecular weight ranging from about 500 to 3,000, an organic diisocyanate (C) and a short chain triol (D) having a molecular weight lower than about 500 and specified structures and, as desired, a short chain diol (B) having a molecular weight ranging from about 50 to 500, in specified ratios.The thermoplastic polyurethane resin provides particularly enhanced heat resistance and solvent resistance with improved dispersibility of a pigment or the like and other resins and favorable compatibility with a solvent or the like.

Abstract: The magnetic recording media are constructed such that a lubricating layer containing an amine compound represented by the formula: ##STR1## (wherein R is a hydrocarbon residue having from 7 to 21 carbon atoms and n is an integer ranging from 1 to 10) is disposed on at least one surface of a non-magnetic substrate with a magnetic layer. The magnetic recording media have an improved lubricating characteristics with a low friction coefficient.

Abstract: The invention provides a novel diorganopolysiloxane compound composed of dimethysiloxane units, methyl (2-perfluoroalkylethyl)siloxane units and methyl acyloxyalkylsiloxane units. The novel diorganopolysiloxane compounds of the invention have excellent lubricating properties so that they are useful as an additive ingredient in various materials such as coating compositions, magnetic layer of recording tapes and the like where lubricity or mold releasability is essential.

Abstract: A magnetic recording medium having a layer containing as a lubricant one or more organo-polysiloxane compounds having the following formula (I): ##STR1## (wherein each of A.sub.1 and A.sub.2 is independently --CH.sub.3, --CH.sub.2 --CH.sub.2 --(CF.sub.2).sub.q --CF.sub.3 or --R.sub.1 OCOR.sub.2 ; R.sub.1 is a divalent hydrocarbon residue having 1 to 5 carbon atoms; R.sub.2 is a monovalent hydrocarbon residue having from 7 to 21 carbon atoms; each of l, m and n is independently O or an integer ranging from 1 to 200; and each of p and q is independently O or an integer ranging from 1 to 12; provided that when at least one of the groups A.sub.1 and A.sub.2 is the group --R.sub.1 OCOR.sub.2, each l, m and n may be O and that, when each group A.sub.1 and A.sub.2 is one of the groups other than the group --R.sub.1 OCOR.sub.2, each l and m may be O and n is an integer ranging from 1 to 200).

Abstract: The magnetic recording medium according to the present invention contains the magnetic layer comprising the magnetic or magnetizable powders or particles and the binder wherein the binder compound is represented by the following general formula (I): ##STR1## (wherein R is methyl group or ethyl group, R.sub.1 is an alkyl group having from 1 to 4 carbon atoms, an alkoxy group having from 1 to 4 carbon atoms or a phenyl group, R.sub.2 is an alkyl group having from 1 to 4 carbon atoms, an alkoxy group having from 1 to 4 carbon atoms, X is a group having a double bond, and Y is a group having a double bond, i is a number in the range of approximately 200 to 800, j is a number in the range of approximately 10 to 200, k is a number in the range up to approximately 200, l is a number in the range of approximately 3 to 100, and m is a number in the range of approximately 1 to 50).

Abstract: The magnetic recording medium contains as a binder a thermoplastic polyurethane resin having a molecular weight larger than about 5,000 and produced by the polyaddition of a long chain diol (A) having a molecular weight ranging from about 500 to 3,000, an organic diisocyanate (C) and a short chain triol (D) having a molecular weight lower than about 500 and specified structures and, as desired, a short chain diol (B) having a molecular weight ranging from about 50 to 500, in specified ratios. The binder may contain a nitrocellulose, a vinyl chloride resin, a polyvinyl butyral, a bisphenol A type polyether or a vinyl chloride-hydroxy carboxylate copolymer as a binder component.The binder provides particularly enhanced heat resistance and solvent resistance with improved dispersibility of a pigment or the like and other resins and favorable compatibility with a solvent or the like.

Abstract: A method of preparing a magnetic recording medium, the surface of which has a very smooth magnetic layer. Magnetic paint is coated on a non-magnetic base, which is then passed between calender rolls which comprise a polyurethane roll and a steel roll heated between approximately 40.degree. C. and 200.degree. C. The hardness of the polyurethane roll is greater than approximately 70.degree. in Shore D, and the pressure between the rolls is between approximately 50 Kg/cm and 500 Kg/cm.