Abstract: A magnetic recording medium comprising a non-magnetic support and at least one magnetic layer containing a ferromagnetic powder and a binder, wherein the non-magnetic support has an intrinsic viscosity of from 0.46 to 0.58 dl/g and a refractive index in a direction of a depth within a range from 1.490 to 1.500.

Abstract: A magnetic recording medium comprising: a magnetic layer; a first radiation curable resin layer; a non-magnetic support having an intrinsic viscosity of from 0.47 to 0.51 dL/g; and a second radiation curable resin layer, in this order, wherein the first radiation curable resin layer contains a filler, and the second radiation curable resin layer contains a filler.

Abstract: A magnetic recording medium including a polymer support having thereon at least one magnetic layer containing a ferromagnetic metal powder having an average major axis length of from 20 to 100 nm or a ferromagnetic hexagonal ferrite powder having an average tabular diameter of from 5 to 40 nm and a binder, the polymer support having an intrinsic viscosity of from 0.47 to 0.51 dL/g, a Young's modulus in the machine direction of from 7.0 to 8.6 GPa, a Young's modulus in the transverse direction of from 5.4 to 8.0 GPa, and a breaking strength in the transverse direction of from 370 to 450 MPa.

Abstract: A magnetic recording medium is composed of a nonmagnetic support provided with on one side of the support a magnetic layer containing a ferromagnetic powder and a binder, and a backing layer on the other side of the nonmagnetic support, wherein the nonmagnetic support is a polyester film having an intrinsic viscosity of from 0.40 to 0.60 dl/g, and contains fillers having filler diameters of from 10 to 500 nm at a filler density of from 1/100 to 50/100 ?m2.

Abstract: Provided is a particulate magnetic recording medium for high-density recording maintaining a high C/N ratio achieving good surface recording density, exhibiting little dropout, and having a low error rate. The magnetic recording medium comprises a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on at least one surface of a nonmagnetic support. Said nonmagnetic support comprises a filler having an aspect ratio ranging from 50 to 10,000 and a thickness ranging from 0.5 to 5 nm.

Abstract: Provided is a particulate magnetic recording medium for high-density recording having a low error rate and good running durability. The magnetic recording medium comprises a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on at least one surface of a nonmagnetic support. Said nonmagnetic support comprises a clay mineral coated with an organic material, and said ferromagnetic powder is a ferromagnetic hexagonal ferrite powder having an average plate diameter ranging from 5 to 40 nm or a ferromagnetic metal powder having an average major axis length ranging from 20 to 100 nm.

Abstract: Provided is a magnetic recording medium having high C/N, low error rate, and excellent running durability. The magnetic recording medium comprises a magnetic layer 1 comprising a ferromagnetic powder and a binder, or comprising a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer 2 comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support. An undercoating layer comprising a clay mineral coated with an organic compound and a binder is comprised between the nonmagnetic support and the magnetic layer 1 or between the nonmagnetic support and the nonmagnetic layer, as well as said clay mineral coated with an organic compound has a thickness ranging from 0.5 to 5 nm and an aspect ratio ranging from 50 to 10,000.

Abstract: A magnetic recording medium containing a support having provided thereon a lower layer containing a nonmagnetic powder and a binder and further provided thereon at least one magnetic layer containing a ferromagnetic powder and a binder. The lower layer can contain as a binder at least a monomer unit containing from 5 to 45% by weight of a (meth)acrylate unit containing a benzene ring and from 1 to 45% by weight of a radical polymerizable monomer unit containing a nitrogen atom, with these units making a total amount of 100% by weight. It can also contain an acrylic resin having a hydrophilic polar group. The magnetic recording medium may also contain a support having provided thereon at least one magnetic layer containing a ferromagnetic powder and a binder each in the dispersed state.

Abstract: Provided is a particulate magnetic recording medium for high-density recording maintaining a high C/N ratio achieving good surface recording density, exhibiting little dropout, and having a low error rate. The magnetic recording medium comprises a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on at least one surface of a nonmagnetic support. Said nonmagnetic support comprises a filler having an aspect ratio ranging from 50 to 10,000 and a thickness ranging from 0.5 to 5 nm.

Abstract: Provided is a magnetic recording medium having high C/N, low error rate, and excellent running durability. The magnetic recording medium comprises a magnetic layer 1 comprising a ferromagnetic powder and a binder, or comprising a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer 2 comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support. An undercoating layer comprising a clay mineral coated with an organic compound and a binder is comprised between the nonmagnetic support and the magnetic layer 1 or between the nonmagnetic support and the nonmagnetic layer, as well as said clay mineral coated with an organic compound has a thickness ranging from 0.5 to 5 nm and an aspect ratio ranging from 50 to 10,000.

Abstract: Provided is a particulate magnetic recording medium for high-density recording having a low error rate and good running durability. The magnetic recording medium comprises a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on at least one surface of a nonmagnetic support. Said nonmagnetic support comprises a clay mineral coated with an organic material, and said ferromagnetic powder is a ferromagnetic hexagonal ferrite powder having an average plate diameter ranging from 5 to 40 nm or a ferromagnetic metal powder having an average major axis length ranging from 20 to 100 nm.

Abstract: A magnetic recording medium comprises: a support; an underlayer containing a non-magnetic powder and a binder; and at least one magnetic layer containing a binder and one of a ferromagnetic metal powder having an average major axis of 0.01 &mgr;m to 0.10 &mgr;m and a crystallite size of 80 Å to 180 Å and a ferromagnetic hexagonal ferrite powder having an average tabular diameter of 5 nm to 40 nm, wherein the magnetic layer has a thickness of 0.01 &mgr;m to 0.5 &mgr;m, and the binder in the magnetic layer comprises a (meth)acrylate copolymer having hydrophilic polar groups and comprising 0 to 75% by weight of alkyl (meth)acrylate units, 5 to 80% by weight of benzene ring-containing (meth)acrylate units and 1 to 75% by weight of nitrogen-containing radical polymerizable monomer units.

Abstract: Provided is a magnetic recording medium having excellent dispersibility, smoothness and electromagnetic characteristics. The magnetic recording medium comprises at least one magnetic layer comprising a ferromagnetic powder and a binder on a nonmagnetic support. Said ferromagnetic powder is a ferromagnetic metal powder having an average major axis length of 10 to 80 nm and a crystallite size of 8 to 18 nm, or a ferromagnetic hexagonal ferrite powder having an average plate diameter of 5 to 40 nm, and said binder comprises 0.2 to 0.7 meq/g of at least one polar group selected from —SO3M, —OSO3M, —PO(OM)2, —OPO(OM)2 and —COOM (where M denotes a hydrogen atom, alkali metal or ammonium salt), and/or 0.5 to 5 meq/g of at least one polar group selected from —CONR1R2, —NR1R2 and —NR1R2R3+ (where R1, R2 and R3 independently denote hydrogen atoms or alkyl groups).

Abstract: The present invention provides a magnetic recording medium, which comprises at least one magnetic layer where ferromagnetic powder and a binder are dispersed, and said magnetic layer is placed on a non-magnetic support, whereby said binder comprises a polyurethane resin obtained through reaction of polytetramethylene glycol and short-chain diol having cyclic structure or short-chain diol having a branched side chain containing two or more carbon atoms, said polytetramethylene glycol is contained in said polyurethane resin in an amount of 35 to 60 weight %, said short-chain diol is contained in said polyurethane resin in an amount of 10 to 40 weight %, and glass transition temperature of said polyurethane resin is within the range of 30° C. to 120° C.

Abstract: The magnetic recording medium of the invention comprises a substrate and a magnetic layer stacked thereon and composed of a dispersion of a ferromagnetic powder in a binder, and is characterized in that the binder contains a polyurethane resin 1 obtained by polymerization of a diol compound having a cyclic structure and a long-chain form of alkyl chain with a diisocyanate compound. Preferably, the polyurethane resin contains as diol components a dimer diol and an aliphatic diol having a medium-chain form of alkyl branched chain. The polyurethane resin may comprise a polyether polyol having a cyclic structure. A dibasic acid in the polyester polyol may contain an aliphatic dibasic acid, the diol component may contain an aliphatic diol that does not include a cyclic structure having an alkyl branched chain, and an chain extender may include a polyester polyol comprising an aliphatic diol having an alkyl branched chain.

Abstract: A magnetic recording medium, comprising at least one magnetic layer, said magnetic layer containing ferromagnetic powder and a binder and placed on a nonmagnetic support member, whereby said binder contains a polyurethane resin, using a diol compound having a cyclic structure and a long-chain alkyl chain, and a polyol with weight average molecular weight (Mw) of 400-5000 and having at least one type of polar group selected from the following groups: —SO3M, —SO4M, —PO3M2, —PO4M2, —NHSO3M, >NSO3M, and —COOM where M represents hydrogen, at least one type of alkali metal of potassium, sodium and lithium, and an organic amine containing at least one type of alkylamine and alkanol.

Abstract: A magnetic recording medium is disclosed, comprising a support having provided thereon a lower layer containing a nonmagnetic powder and a binder and further provided thereon at least one magnetic layer containing a ferromagnetic powder and a binder, wherein said lower layer contains as a binder at least a monomer unit comprising from 5 to 45% by weight of a (meth)acrylate unit containing a benzene ring and from 1 to 45% by weight of a radical polymerizable monomer unit containing a nitrogen atom, with these units making a total amount of 100% by weight, and also contains an acrylic resin having a hydrophilic polar group, and a magnetic recording medium is disclosed,comprising a support having provided thereon at least one magnetic layer containing a ferromagnetic powder and a binder each in the dispersed state, wherein the magnetic layer contains at least a monomer unit comprising from 15 to 75% by weight of an alkyl (meth)acrylate as a binder and from 1 to 45% by weight of a radical polymerizable monomer un

Abstract: A magnetic recording medium comprises: a support; an underlayer containing a non-magnetic powder and a binder; and at least one magnetic layer containing a binder and one of a ferromagnetic metal powder having an average major axis of 0.01 &mgr;m to 0.10 &mgr;m and a crystallite size of 80 Å to 180 Å and a ferromagnetic hexagonal ferrite powder having an average tabular diameter of 5 nm to 40 nm, wherein the magnetic layer has a thickness of 0.01 &mgr;m to 0.5 &mgr;m, and the binder in the magnetic layer comprises a (meth)acrylate copolymer having hydrophilic polar groups and comprising 0 to 75% by weight of alkyl (meth)acrylate units, 5 to 80% by weight of benzene ring-containing (meth)acrylate units and 1 to 75% by weight of nitrogen-containing radical polymerizable monomer units.

Abstract: The present invention provides a magnetic recording medium, which comprises a magnetic layer having ferromagnetic powder dispersed in a binder on a non-magnetic support member, wherein the non-magnetic support member is made of aromatic polyamide, an undercoating layer is provided between said non-magnetic support member and a lower non-magnetic layer, or between the non-magnetic support member and the magnetic layer, said undercoating layer comprising polyamide resin having tertiary amino group and containing repeated structural units expressed by the following formulae (1) and (2).

Abstract: The present invention provides a magnetic recording medium having high electromagnetic transfer characteristics and good running durability, whereby a polyester polyol comprising an aliphatic dibasic acid and an aliphatic diol component having no cyclic structure is used as a binder, and a polyurethane is contained, which comprises a polyester polyol having an aliphatic diol where 70 mol % or more of the aliphatic diol has alkyl branched side chain having 2 or more carbon atoms, and said polyurethane has urethane group concentration of 3.0 to 4.0 mmol/g, and said ferromagnetic powder has iron with yttrium at a yttrium/iron ratio of 0.5 to 20 atomic % as a major component.