Abstract: A resin composition includes an epoxy compound, a triphenylbenzene compound, an inorganic particle including a magnesium oxide (MgO) or the like, and phosphorus (P). The triphenylbenzene compound is a compound that includes 1,3,5-triphenylbenzene as a skeleton, and that includes a reactive group introduced in the skeleton. A content (mass %) of the phosphorus expressed by (mass of the phosphorus/mass of nonvolatile content excluding the inorganic particle)×100 is from 0.5 mass % to 4.3 mass %.

Abstract: A high recording density magnetic recording medium and a manufacturing method therefor are provided. The dilution stability during preparation of magnetic paint is improved and, thereby, even when the magnetic paint concentration is lowered, no problem occurs with the surface roughness and the output of the thin magnetic layer. The magnetic recording medium includes at least a magnetic layer on one surface of a non-magnetic support, wherein the magnetic layer contains a magnetic powder, a vinyl chloride resin having a degree of polymerization of at least 270 and an aliphatic polyester polyurethane resin to serve as binder resins, an aromatic compound having a substituent R (where R is —COOH, —(COOH)2, —OPO(OH)2, —PO(OH)2, or —SO3H), and a phosphoric acid ester. The ratio of binder resins in the magnetic paint is set at 2.0 percent by weight or less relative to a total sum of the binder resins and a solvent.

Abstract: The present invention provides a magnetic recording medium comprising a magnetic layer with excellent surface smoothness, which comprises a thin film magnetic layer of thickness in a range from 0.03 to 0.30 ?m that is ideal for short wavelength recording, and displays superior electromagnetic conversion characteristics. The magnetic recording medium comprises a magnetic layer containing at least a ferromagnetic powder and a binder resin on one surface of a non-magnetic support, wherein the thickness of the magnetic layer is within a range from 0.03 to 0.30 ?m, and the number of concavities with a depth of 30 nm or greater in the surface of the magnetic layer is 5 per 1 cm2 of surface area or less. Preferably, the value of the average depth Rv6 of the surface of the magnetic layer, as measured by a contact type surface roughness meter, is 12 nm or less.

Abstract: The present invention provides a magnetic recording medium which has a back coat layer excellent in surface smoothness and durability and is excellent in electromagnetic conversion property. A magnetic recording medium, comprising at least a non-magnetic support, a lower non-magnetic layer on one surface of the non-magnetic support, an upper magnetic layer on the lower non-magnetic layer, and a back coat layer on the other surface of the non-magnetic support, wherein the lower non-magnetic layer contains at least carbon black, a non-magnetic inorganic powder other than carbon black, and a binder resin material, the upper magnetic layer contains at least a ferromagnetic powder, and a binder resin material, and the back coat layer contains at least carbon black, a non-magnetic inorganic powder other than carbon black, a carboxylic acid amine salt, a phosphate amine salt, and a binder resin material.

Abstract: The present invention provides a high-capacity magnetic recording medium which has a thinned back coat layer excellent in surface smoothness and durability and is excellent in electromagnetic conversion property. A magnetic recording medium comprising at least a non-magnetic support, a lower non-magnetic layer on one surface of the non-magnetic support, an upper magnetic layer on the lower non-magnetic layer, and a back coat layer on the other surface of the non-magnetic support, wherein the lower non-magnetic layer contains at least carbon black, a non-magnetic inorganic powder other than carbon black, and a binder resin material, the upper magnetic layer contains at least a ferromagnetic powder, and a binder resin material, and the back coat layer contains at least carbon black, a non-magnetic inorganic powder other than carbon black, a phosphate amine salt, and nitrocellulose resin as a binder resin material, and has a thickness of 0.3 to 0.8 ?m.

Abstract: The present invention provides a magnetic recording medium comprising a magnetic layer with excellent surface smoothness, which comprises a thin film magnetic layer of thickness in a range from 0.03 to 0.30 ?m that is ideal for short wavelength recording, and displays superior electromagnetic conversion characteristics. The magnetic recording medium comprises a magnetic layer containing at least a ferromagnetic powder and a binder resin on one surface of a non-magnetic support, wherein the thickness of the magnetic layer is within a range from 0.03 to 0.30 ?m, and the number of concavities with a depth of 30 nm or greater in the surface of the magnetic layer is 5 per 1 cm2 of surface area or less. Preferably, the value of the average depth Rv6 of the surface of the magnetic layer, as measured by a contact type surface roughness meter, is 12 nm or less.

Abstract: The present invention provides a magnetic recording medium which has a back coat layer excellent in surface smoothness and durability and is excellent in electromagnetic conversion property. A magnetic recording medium, comprising at least a non-magnetic support, a lower non-magnetic layer on one surface of the non-magnetic support, an upper magnetic layer on the lower non-magnetic layer, and a back coat layer on the other surface of the non-magnetic support, wherein the lower non-magnetic layer contains at least carbon black, a non-magnetic inorganic powder other than carbon black, and a binder resin material, the upper magnetic layer contains at least a ferromagnetic powder, and a binder resin material, and the back coat layer contains at least carbon black, a non-magnetic inorganic powder other than carbon black, a carboxylic acid amine salt, a phosphate amine salt, and a binder resin material.

Abstract: The present invention provides a magnetic recording medium comprising a thin film magnetic layer of thickness in a range from 0.03 to 0.30 ?m, and having excellent surface smoothness and superior electromagnetic conversion characteristics. The magnetic recording medium comprises a lower non-magnetic layer containing at least a non-magnetic powder and a binder resin on one surface of a non-magnetic support, an upper magnetic layer containing at least a ferromagnetic powder and a binder resin on the lower non-magnetic layer, and a back coat layer on the other surface of the non-magnetic support, wherein the thickness of the upper magnetic layer is within the range from 0.03 to 0.30 ?m, the AFM surface roughness Ra of the upper magnetic layer is 6 nm or less, and the number of concavities with a depth of 30 nm or greater in the surface of the upper magnetic layer is 5 per 1 cm2 of surface area or less.

Abstract: A magnetic recording medium has a non-magnetic layer and a magnetic layer formed in that order on one surface of a non-magnetic support and a back coat layer formed on the other surface of the non-magnetic support. The non-magnetic layer is formed so as to include at least one of ?-iron oxide and ?-iron hydroxide. The magnetic layer is formed so as to include a ferromagnetic alloy powder. The back coat layer is formed so as to include carbon black, and barium sulfate. At least one of the non-magnetic layer and the magnetic layer includes lubricant. The layers are formed so that the amount of SO42? eluted when the magnetic recording medium is immersed in water at 70° C. is in a range of 300 ppm to 600 ppm inclusive relative to the weight of the magnetic recording medium.

Abstract: The present invention provides a magnetic recording medium comprising a magnetic layer with excellent surface smoothness, which comprises a thin film magnetic layer of thickness in a range from 0.03 to 0.30 ?m that is ideal for short wavelength recording, and displays superior electromagnetic conversion characteristics. The magnetic recording medium comprises a magnetic layer containing at least a ferromagnetic powder and a binder resin on one surface of a non-magnetic support, wherein the thickness of the magnetic layer is within a range from 0.03 to 0.30 ?m, and the number of concavities with a depth of 30 nm or greater in the surface of the magnetic layer is 5 per 1 cm2 of surface area or less. Preferably, the value of the average depth Rv6 of the surface of the magnetic layer, as measured by a contact type surface roughness meter, is 12 nm or less.

Abstract: The present invention provides a high recording density magnetic recording medium with excellent surface smoothness, as well as excellent electromagnetic conversion characteristics and durability. A magnetic recording medium comprising a lower non-magnetic layer containing at least a non-magnetic powder and a binder resin on a non-magnetic support, and an upper magnetic layer with a thickness of 0.2 ?m or less on said lower non-magnetic layer, wherein said lower non-magnetic layer contains an acicular powder of hydrated iron oxide as the non-magnetic powder, and said lower non-magnetic layer contains a fatty acid and a fatty acid amide. Preferably the acicular powder of hydrated iron oxide is goethite with an average long axial length of 0.15 ?m or less.

Abstract: A magnetic recording medium is prepared by coating a dispersion of non-magnetic powder and ferromagnetic powder in a binder and a dispersion of ferromagnetic powder in a binder to a non-magnetic substrate by a wet-on-wet coating technique to form subordinate and magnetic layers on the substrate, and subjecting the layers to magnetic field orientation. The subordinate layer has a Br of 80 to 400 gauss, and the magnetic layer has a thickness of 0.1 to 0.4 ?m. The medium has surface smoothness and good electromagnetic characteristics and lends itself to recording and reproducing signals having a minimum wavelength of 0.2 to 0.7 ?m.

Abstract: A high recording density magnetic recording medium and a manufacturing method therefor are provided. The dilution stability during preparation of magnetic paint is improved and, thereby, even when the magnetic paint concentration is lowered, no problem occurs with the surface roughness and the output of the thin magnetic layer. The magnetic recording medium includes at least a magnetic layer on one surface of a non-magnetic support, wherein the magnetic layer contains a magnetic powder, a vinyl chloride resin having a degree of polymerization of at least 270 and an aliphatic polyester polyurethane resin to serve as binder resins, an aromatic compound having a substituent R (where R is —COOH, —(COOH)2, —OPO(OH)2, —PO(OH)2, or —SO3H), and a phosphoric acid ester. The ratio of binder resins in the magnetic paint is set at 2.0 percent by weight or less relative to a total sum of the binder resins and a solvent.

Abstract: The average major-axis length (L) of a ferromagnetic alloy powder primarily contained together with a binder in a magnetic layer provided on at least one surface of a non-magnetic support is less than 0.10 ?m, and the ferromagnetic alloy powder contains Co at a content of 15 to 28 at % relative to Fe, and furthermore, contains Y at a content of 22 ?mol/m2 or more with respect to a specific surface area (Sc) calculated from the above-mentioned average major-axis length (L) and the crystallite diameter (d). A coating-type high-recording-density magnetic recording medium has excellent surface properties, an excellent electromagnetic transducing characteristic especially in short wavelength regions and high reliability.

Abstract: The present invention provides a magnetic recording medium comprising a magnetic layer with excellent surface smoothness, which comprises a thin film magnetic layer of thickness in a range from 0.03 to 0.30 &mgr;m that is ideal for short wavelength recording, and displays superior electromagnetic conversion characteristics. The magnetic recording medium comprises a magnetic layer containing at least a ferromagnetic powder and a binder resin on one surface of a non-magnetic support, wherein the thickness of the magnetic layer is within a range from 0.03 to 0.30 &mgr;m, and the number of concavities with a depth of 30 nm or greater in the surface of the magnetic layer is 5 per 1 cm2 of surface area or less. Preferably, the value of the average depth Rv6 of the surface of the magnetic layer, as measured by a contact type surface roughness meter, is 12 nm or less.

Abstract: The present invention provides a magnetic recording medium comprising a thin film magnetic layer of thickness in a range from 0.03 to 0.30 &mgr;m, and having excellent surface smoothness and superior electromagnetic conversion characteristics. The magnetic recording medium comprises a lower non-magnetic layer containing at least a non-magnetic powder and a binder resin on one surface of a non-magnetic support, an upper magnetic layer containing at least a ferromagnetic powder and a binder resin on the lower non-magnetic layer, and a back coat layer on the other surface of the non-magnetic support, wherein the thickness of the upper magnetic layer is within the range from 0.03 to 0.30 &mgr;m, the AFM surface roughness Ra of the upper magnetic layer is 6 nm or less, and the number of concavities with a depth of 30 nm or greater in the surface of the upper magnetic layer is 5 per 1 cm2 of surface area or less.

Abstract: The present invention provides a magnetic recording medium, in particular a linear recording tape for use with computers, comprising a back coat layer with proper strength and having excellent electromagnetic conversion characteristics and excellent running durability. The magnetic recording medium comprises a lower non-magnetic layer on one surface of a non-magnetic support, an upper magnetic layer on the lower non-magnetic layer, and the back coat layer on the other surface of the non-magnetic support. And the magnetic layer has a SENDUST abrasion volume SMC of 3.0×104(&mgr;m)3/m or less and a ratio (SBC/SMC) of a SENDUST abrasion volume SBC by the back coat layer to the SENDUST abrasion volume SMC by the magnetic layer is in the range of 0.5 to 3.0.

Abstract: The present invention provides a high recording density magnetic recording medium with improved dropout and excellent surface smoothness and electromagnetic conversion characteristics, as well as a process for producing such a medium. A magnetic recording medium comprising a lower non-magnetic layer containing at least a non-magnetic powder and a binder resin on one surface of a non-magnetic support, an upper magnetic layer containing at least a ferromagnetic powder and a binder resin on said lower non-magnetic layer, and a back coat layer on an opposite surface of said non-magnetic support, wherein said lower non-magnetic layer contains an acicular powder of hydrated iron oxide as the non-magnetic powder, said ferromagnetic powder has an average long axial length of 0.1 &mgr;m or less, and said upper magnetic layer has a surface roughness (center line average roughness: Ra) of 2.4 nm or less. After curing the lower non-magnetic layer, the magnetic layer is applied and formed.

Abstract: The average major-axis length (L) of a ferromagnetic alloy powder primarily contained together with a binder in a magnetic layer provided on at least one surface of a magnetic support is less than 0.10 &mgr;m, and the ferromagnetic alloy powder contains Co at a content of 15 to 28 at % relative to Fe, and furthermore, contains Y at a content of 22 &mgr;mol/m2 or more with respect to a specific surface area (Sc) calculated from the above-mentioned average major-axis length (L) and the crystallite diameter (d). A coating-type high-recording-density magnetic recording medium has excellent surface properties, an excellent electromagnetic transducing characteristic especially in short wavelength regions and high reliability.

Abstract: The present invention provides a high recording density magnetic recording medium with improved dropout and excellent surface smoothness and electromagnetic conversion characteristics, as well as a process for producing such a medium. A magnetic recording medium comprising a lower non-magnetic layer containing at least a non-magnetic powder and a binder resin on one surface of a non-magnetic support, an upper magnetic layer containing at least a ferromagnetic powder and a binder resin on said lower non-magnetic layer, and a back coat layer on an opposite surface of said non-magnetic support, wherein said lower non-magnetic layer contains an acicular powder of hydrated iron oxide as the non-magnetic powder, said ferromagnetic powder has an average long axial length of 0.1 &mgr;m or less, and said upper magnetic layer has a surface roughness (center line average roughness: Ra) of 2.4 nm or less. After curing the lower non-magnetic layer, the magnetic layer is applied and formed.