Abstract: A lubricant composition comprising (A) a compound of the formula: R1—COO—R2 wherein R1 is a higher aliphatic hydrocarbon residue and R2 is an aliphatic hydrocarbon residue which may contain fluorine atom(s) and/or oxygen atom(s), and (B) a compound of the formula: wherein R3 is a higher aliphatic hydrocarbon residue; R4 and R5 are independently a hydrogen atom or an aliphatic hydrocarbon residue which may contain fluorine atom(s) and/or oxygen atom(s), gives a lubricant layer in a magnetic recording medium having good running durability, still life and weather resistance.

Abstract: A magnetic recording medium includes a non-magnetic supporting substrate, and a magnetic layer on one surface thereof and a back coat layer on the other surface thereof, said back coat layer having a non-magnetic powder dispersed in a binder. The back coat layer contains carbon black and an inorganic powder as said non-magnetic powder. The carbon black contains a carbon black species having an average primary particle diameter of 40 to 70 nm, and the inorganic powder has an average primary particle diameter of 40 to 150 nm and a Mohs hardness of at least 3, with a weight ratio between said carbon black and said inorganic powder being 100:0.5 to 100:10. The binder comprises a phenoxy resin, a thermoplastic polyurethane resin having an amino group in a molecule thereof, and a polyisocyanate compound.

Abstract: A magnetic recording (vapor deposition) film medium having improved friction characteristics, running durability, and still characteristics are provided.

Abstract: A magnetic recording medium having an intermediate layer excellent in conductivity, surface properties and strength, and excellent in electromagnetic characteristics, physical properties, etc., which comprises a non-magnetic intermediate layer having a thickness of 0.5 .mu.m to 3.0 .mu.m formed on at least one surface of a non-magnetic support, and a magnetic layer formed on the intermediate layer, the magnetic layer being mainly composed of a ferromagnetic powder and a binder and having a thickness of 0.1 .mu.m to 0.5 .mu.m, in which said magnetic layer is formed on the intermediate layer at least in a dry state, and the intermediate layer comprises(A) an inorganic material having an average particle size of 10 nm to 50 nm and a Mohs' hardness of 7 or less,(B) an inorganic material having an average particle size of 100 nm to 500 nm and a Mohs' hardness of 9 or more,(C) carbon black,a lubricant and a binder.

Abstract: A magnetic layer is provided on a nonmagnetic base with a non-ferromagnetic layer interposed between them. Non-ferromagnetic particulate iron oxide is incorporated in the non-ferromagnetic layer. In addition to, or in place of, this iron oxide, non-structural carbon having a mean particle diameter of 10 to 60 nm, a specific surface area of 150 m2/g as measured by the BET method and a DBP oil absorption of 100 ml/100 g or less may be used. This makes it possible to achieve a magnetic recording medium having excellent surface properties and good-enough electromagnetic transducing characteristics.

Abstract: In a magnetic recording medium comprising on a non-magnetic substrate a magnetic layer obtained by dispersing ferromagnetic powder in an electron beam-curable resin followed by electron beam curing or a backcoat layer obtained by curing an electron beam-curable resin with electron beams, a combination of an electron beam-curable vinyl chloride resin having a sulfur-containing polar group and an electron beam-curable urethane resin having a phosphorus-containing polar group is used as the electron beam-curable resin. This results in improvements in dispersibility, surface smoothness, and electromagnetic characteristics, as well as a lowering of error rate in high density digital recording. Storage property is good.

Abstract: In order to reduce the coefficient of friction of a coated type magnetic recording medium and improve the running stability and electromagnetic conversion characteristics thereof, a carbon black having a mean primary particle diameter of 25 to 65 m.mu.m with the standard deviation .sigma. of the particle size distribution lying at 12 to 24 m.mu.m is incorporated in the magnetic layer.

Abstract: In a magnetic recording medium comprising a substrate and a magnetic layer thereon, the magnetic layer is formed by coating a composition of a binder, preferably radiation-curable binder and a needle magnetic material, passing the coating through a magnetic field to forcedly re-orient the magnetic particles to form pores having an average pore area of 6.times.10.sup.-5 to 7.times.10.sup.-1 .mu.m.sup.2, and curing the coating, thereby minimizing output fluctuation and improving durability. Preferably lubricant is present in the pores.