Abstract: A coating film, which is constituted of a polysilazane, is formed on a substrate. The polysilazane in the coating film is then oxidized by being brought into contact with active oxygen or ozone, or by being exposed to light. A protective film, which is constituted of silica, is thereby formed on the substrate. An inorganic protective film is also provided, which comprises an inorganic oxide film, that is obtained by subjecting a polysilazane coating film to oxidation treatment, and fine particles contained in the inorganic oxide film.

Abstract: A magnetic recording medium excellent in running properties, durability and shelf stability. The magnetic recording medium has a magnetic layer of a ferromagnetic metal thin film formed over at least one surface of a non-magnetic base, with or without an inorganic protective layer formed on the magnetic layer. A surface layer consisting essentially of a salt of a phosphoric alkyl ester compound with an alkylamine compound, which is represented by the following formula (1) or (2), and a fluorine-containing carboxylic acid ester compound is provided on the magnetic layer or on the inorganic protective layer: ##STR1## where: R.sup.1 and R.sup.2, which may be the same or different from each other, are a hydrocarbon or fluorinated hydrocarbon group having from 2 to 26 carbon atoms; R.sup.A, R.sup.B, R.sup.C and R.sup.D are hydrogen, or a hydrocarbon or fluorinated hydrocarbon group having not more than 26 carbon atoms; and m is 1 or 2.

Abstract: The present invention provides a magnetic recording medium, which comprises a salt of a perfluoropolyether modified with phosphoric acid at molecular terminal and an alkylamine on a magnetic layer having a ferromagnetic metal thin film at least on one side of a non-magnetic support member or a protective film formed on the magnetic layer, and it shows excellent properties under any operating conditions including low temperature and low humidity.

Abstract: The magnetic recording medium has a magnetic layer of a ferromagnetic metal thin film over at least one surface of a non-magnetic base, in which a phosphoric monoester compound which is represented by R.sub.1 --OPO(OH).sub.2, a florine-containing fatty acid ester compound which is represented by R.sub.2 --COO--R.sub.3, and a fluorinated hydrocarbon in which some of the hydrogen atoms of a hydrocarbon having from 14 to 40 carbon atoms have been replaced by fluorine atoms, are present on the magnetic layer. R.sub.1 is a hydrocarbon group having from 8 to 26 carbon atoms. R.sub.2 and R.sub.3 are each a hydrocarbon group having from 8 to 26 carbon atoms, or a fluorinated hydrocarbon group in which some or all of the hydrogen atoms of a hydrocarbon group having from 8 to 26 carbon atoms have been replaced by fluorine atoms. R.sub.2 and R.sub.3 may be the same or different from each other. At least either one of R.sub.2 and R.sub.3 contains fluorine atoms.

Abstract: A metal thin film type magnetic recording medium which is excellent in running properties, durability and shelf stability. The magnetic recording medium has a ferromagnetic metal thin film formed over a non-magnetic base, and further has on the ferromagnetic metal thin film a lubricant layer containing a phosphoric monoester compound represented by the following formula (1), and an alkylene oxide group-containing fluorinated carboxylic acid ester compound represented by the following formula (2) or (3):R.sup.1 --OPO(OH).sub.2 Formula (1)where R.sup.1 is a hydrocarbon group having from 8 to 26 carbon atoms.Rf.sup.1 --R.sup.2 --COO--(R.sup.3 O).sub.n --R.sup.4 Formula (2)Rf.sup.2 --R.sup.2 --COO--(R.sup.3 O).sub.n --R.sup.4 --Rf.sup.3Formula (3)where Rf.sup.1, Rf.sup.2, Rf.sup.3 : (CF.sub.3).sub.a CF.sub.3-a (CF.sub.2).sub.b -- a: 1 to 3 a+b: 1 to 11 n=l to 8R.sup.2 is an alkylene or alkenyl group having from 2 to 14 carbon atoms;R.sup.3 is an alkylene group having from 1 to 4 carbon atoms; andR.sup.

Abstract: The magnetic recording medium of the present invention comprises a ferromagnetic metallic thin film formed on a non-magnetic support, whereby a protective layer is formed on the ferromagnetic metallic thin film, said protective layer contains at least one type of thiouracil cyclic compounds having hydrocarbon group and at least one type of fluorine compounds having hydrocarbon group, or at least one type of tetrazaindene cyclic compounds and at least one type of fluorine compounds having hydrocarbon group, and no rusting occurs even when it is repeatedly run.

Abstract: Disclosed is a process for producing a magnetic recording medium comprising subjecting a ferromagnetic metal thin film formed on a non-magnetic support by vacuum film formation to a high humidity treatment in an atmosphere of from 50 to 90% RH at a temperature of from 10.degree. to 50.degree. C. and then applying a lubricant having a polar group in the molecule thereof to the thus treated ferromagnetic metal thin film, and a magnetic recording medium comprising a non-magnetic support having thereon a ferromagnetic metal thin film, wherein the ferromagnetic metal thin film has provided thereon a double lubricant layer comprising (i) a lower layer comprising a polar group-containing perfluoropolyether and (ii) an upper layer comprising a perfluoropolyether having no polar group, the polar group-containing perfluoropolyether has a viscosity of from 200 to 1000 cSt at room temperature and the perfluoropolyether having no polar group has a viscosity of 50 cSt or less at room temperature.

Abstract: A magnetic recording medium is disclosed, comprising a non-magnetic support having an undercoating layer provided on said non-magnetic support and a magnetic layer provided on said undercoating layer, wherein said undercoating layer provided between said non-magnetic support and said magnetic layer comprises mainly a non-magnetic fine particles having an average particle size of 100 to 350 .ANG. and a binder; said binder is a polyester resin having a glass transition temperature (Tg) of 40.degree. C. or less, said undercoating layer has a thickness of 30 to 250 .ANG.; and said magnetic layer is a ferromagnetic metal thin film.

Abstract: A magnetic recording medium having a magnetic recording layer on at least one surface of a non-magnetic support, wherein the magnetic recording layer has thereon a lubricant layer containing at least one fluoroalkyl sulfo compound having an ether or ester linkage, which is represented by the following formula (1). The magnetic recording medium is free from corrosion of the magnetic recording layer and has a low coefficient of friction and excellent running durability and shelf stability. The lubricant layer is particularly suitable for a magnetic recording medium having a metal thin film with or without an inorganic protective film as a magnetic recording layer.(Rf--A--R--SO.sub.3).sub.k X Formula (1)wherein Rf represents a fluoroalkyl group or a perfluoroalkyl group; A represents ##STR1## R represents an alkylene group; k represents an integer of 1 or 2; and X represents --H, --M, --MH (wherein M is an alkali metal or an alkali earth metal), or any one of primary to quaternary ammoniums.