Abstract: A magnetic recording medium comprising a non magnetic support having thereon a magnetic layer comprising binder resins, ferromagnetic particles and an organic phosporus compound.

Abstract: A magnetic recording medium having an improved running durability is disclosed, which comprises a non-magnetic support having formed thereon a magnetic layer mainly composed of a ferromagnetic powder and a binder resin, wherein an ester compound selected from the group consisting of a phthalic acid diester represented by formula (I) and a benzenetricarboxylic acid triester represented by formula (II) is contained in the magnetic layer or coated on the magnetic layer: ##STR1## wherein R.sup.1 and R.sup.2, which may be the same or different, each represents a straight chain or branched alkyl or alkenyl group and the sum of the carbon atoms of R.sup.1 and R.sup.2 is at least 22; and ##STR2## wherein R.sup.3, R.sup.4 and R.sup.5, which may be the same or different, each represents a straight chain or branched alkyl or alkenyl group and the sum of the carbon atoms of R.sup.3, R.sup.4 and R.sup.

Abstract: A magnetic recording medium is disclosed, which has a magnetic layer on a non-magnetic support, wherein at least a mixture of ester compounds shown by formula (I) obtained by the reaction of a straight chain or branched fatty acid having from 12 to 30 carbon atoms and branched alcohols having from 10 to 32 carbon atoms synthesized by oxo synthesis is retained in or on the magnetic layer: ##STR1## wherein R.sub.1 represents a straight chain or branched alkyl group having from 11 to 29 carbon atoms or a straight chain or branched alkenyl group having from 11 to 29 carbon atoms, and R.sub.2 represents a branched alkyl group having from 10 to 32 carbon atoms. The magnetic recording medium has an excellent running durability in wide ranges of temperature and humidity condition.

Abstract: A magnetic recording medium is disclosed, which comprises a non-magnetic support having provided thereon a magnetic layer mainly composed of a ferromagnetic powder and a binder resin comprising (i) a polymer having at least one polar group selected from --SO.sub.3 M.sup.1, --OSO.sub.3 M.sup.1, --COOM.sup.1, ##STR1## wherein M.sup.1 represents a hydrogen atom, Li, Na or NR.sub.4 (wherein R represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkanol group), and M.sup.2 represents a hydrogen atom, Li, Na, an alkyl group, or NR.sub.4 (wherein R has the same significance as defined above); or (ii) a compound having at least one polar group selected from --SO.sub.3 M.sup.3, --COOM.sup.3, and --PO.sub.3 (M.sup.3).sub.2 (wherein M.sup.

Abstract: A magnetic recording medium is disclosed, comprising a nonmagnetic support having thereon a magnetic layer, wherein at least one of ester compounds represented by formula (I) is present in or on the magnetic layer, ##STR1## wherein R.sub.1 represents a straight chain, saturated alkyl group having 6 to 12 carbon atoms, R.sub.2 represents a straight chain, saturated alkyl group having 4 to 10 carbon atoms, and R represents a branched or straight chain alkyl group having 4 to 22 carbon atoms.

Abstract: A magnetic recording medium comprising a non-magnetic support having provided thereon a magnetic layer comprising a ferromagnetic powder dispersed in a binder,wherein said binder comprises a polymer containing a polar group selected from --SO.sub.3 M, --OSO.sub.3 M, --COOM, ##STR1## where M represents a hydrogen atom, Li, Na, K or NR.sub.4 where R represents a hydrogen atom or an alkyl group, and M' represents a hydrogen atom, Li, Na, K, an alkyl group or NR.sub.4 where R represents a hydrogen atom or an alkyl group, andsaid magnetic layer contains at least one fatty acid ester compound represented by formula (I), at least one fatty acid ester compound represented by formula (II), and at least one fatty acid having from 11 to 35 carbon atoms: ##STR2## wherein R.sup.1 represents a linear or branched chain hydrocarbon group having from 11 to 35 carbon atoms, R.sup.

Abstract: A magnetic recording medium comprises a nonmagnetic support and a magnetic recording layer containing a ferromagnetic powder which is provided on the support. The magnetic recording layer contains a binder resin having a acid residue or a salt thereof and a fatty acid ester compound having the formula (I): ##STR1## wherein R is a hydrocarbon group having 11-21 carbon atoms, R.sup.1 is hydrogen atom or a hydrocarbon group having 1-3 carbon atoms, and R.sup.2 and R.sup.3 are the same or different and each is a hydrocarbon group having 1-8 carbon atoms. The total number of carbon atoms contained in R.sup.1, R.sup.2 and R.sup.3 being not less than 3 carbon atoms. Alternatively, the fatty acid ester can be coated on the magnetic layer.

Abstract: A magnetic recording medium comprising a nonmagnetic support and a magnetic recording layer provided on the support, wherein the magnetic recording layer contains a compound having a polar group (i.e., a carboxylic acid group, a carboxylic acid salt group, a sulfonic acid group or a sulfonic acid salt group) which is bonded to an aromatic ring directly or indirectly through a polymethylene group having not more than 4 carbon atoms or an unsaturated straight-chain hydrocarbon group having not more than 4 carbon atoms.