Matsushita Electric Industrial Co., Ltd.

Kenji Kuwahara

Mikio Murai

Masaru Odagiri

Hideyuki Ueda

Hiroshi Seki

Kiyosi Takahasi

Kiyoshi Takahashi

Sadayuki Okazaki

Yukikazu Ohchi

Shinichi Tanaka

Noriyasu Echigo

Toru Ishida

Masumi Hattori

Tomi Sato

Tetuo Fuchi

A lubricant composition having excellent lubricity and comprising at least one compound selected among fluorine compounds each having a perfluoroalkyl or perfluoroether group and an alkyl or alkenyl group in the molecule and at least one compound selected among fluorine compounds each having a perfluoropolyether group in the molecule; and a magnetic recording medium excellent in running durability and still durability and comprising a nonmagnetic substrate (1) and, formed thereon in this order, a ferromagnetic thin metal film (2), a carbon film (3), and a lubricant layer (4), wherein the lubricant layer (4) contains the lubricant composition.

Lubricant composition magnetic recording medium, and process for producing magnetic recording medium

A ferromagnetic metal thin film recording medium having a nonmagnetic substrate, a ferromagnetic metal thin film formed on the nonmagnetic substrate, a dry etched layer which is formed in a surface layer of the ferromagnetic metal thin film and contains oxygen atoms in a higher concentration than the remaining part of the ferromagnetic metal thin film, a hard carbonaceous film formed on the dry etched layer of the ferromagnetic metal thin film, a lubricant layer formed on said hard carbonaceous film, and optionally a modified layer which is formed on the hard carbonaceous film and has a thickness of less than 3 nm, and comprises carbon, nitrogen and oxygen atoms with an atomic ratio of nitrogen to carbon being at least 0.8%, which recording medium has improved running stability, durability and weatherability while maintaining electromagnetic conversion characteristics.

Method for producing a magnetic recording medium having a carbon

A magnetic recording medium of the present invention includes: a non-magnetic substrate; a ferromagnetic thin metal layer formed on the non-magnetic substrate; and a carbon layer and a lubricant layer in contact with the carbon layer, which is formed above the ferromagnetic thin metal layer so that the lubricant layer is an outermost layer, wherein the carbon layer contains nitrogen atoms, a Raman spectrum of the carbon layer has a peak A in the range of about 1310 to about 1410 cm.sup.-1 and a peak B in the range of about 1520 to about 1570 cm.sup.-1, and a ratio of integrated intensities of the peak A to the peak B is in the range of about 1.2 to about 2.0.

Magnetic recording medium having a carbon protective film containing

A magnetic recording medium produced by treating a magnetic recording medium which comprises a non-magnetic substrate and a magnetic layer formed on said substrate in an atmosphere kept at a temperature of at least 50.degree. C., with applying a tension of 1 gf. or less per 10 mm width to said magnetic recording medium in a treating time which is in a range on or above a line having a slope of at least 5000 in terms of .DELTA.ln(L)/.DELTA.(1/T) and passing a point of 0.5 second at 100.degree. C., when ln(L) is Arrhenius plotted against an inverse of an absolute temperature T (1/T), which medium has suppressed change of magnetic properties with time and improved corrosion resistance.

Method for producing magnetic recording medium

A magnetic recording medium comprising a non-magnetic substrate, a ferromagnetic thin film on the non-magnetic substrate, a hard carbon film on the ferromagnetic thin film, a modified layer of which atomic ratio of nitrogen/carbon is 0.8% or more, and of which thickness is less than 3 nm on the hard carbon film, and a lubricant layer on the modified layer, has excellent electromagnetic conversion characteristic, running stability, durability, and weatherability.

Magnetic recording medium and its manufacturing method

Magnetic recording medium having a ferromagnetic metal thin film, a dry

A magnetic recording media comprising a non-magnetic substrate, a ferromagnetic thin film on the non-magnetic substrate, a hard carbon film on the ferromagnetic thin film, a modified layer of which atomic ratio of nitrogen/carbon is 0.8% or more, and of which thickness is less than 3 nm on the hard carbon film, and a lubricant layer on the modified layer, has excellent electromagnetic conversion characteristic, running stability, durability, and weatherability.

Method of manufacturing a magnetic recording medium

A magnetic recording medium comprising a back coating layer formed on a surface reverse to a magnetic layer and a carbonaceous film which is formed on the back coating layer and contains fluorine atoms and silicon atoms and/or nitrogen atoms and in which a concentration of fluorine atoms decreases in a depth direction from a surface of the carbonaceous film, while a concentration of the silicon and/or nitrogen atoms increases in the depth direction from the surface of the carbonaceous film, which recording medium has improved running stability, durability and weatherability while electromagnetic conversion characteristics are maintained.

Method for forming film by plasma CVD

A magnetic recording medium comprising a non-magnetic substrate, a ferromagnetic metal film formed on said non-magnetic substrate, a carbon film which is formed on said ferromagnetic metal film and in which a concentration of at least one element selected from the group consisting of silicon, phosphorus, sulfur, tin and indium is or concentrations of boron and at least one element selected from the group consisting of tin and indium are decreased in a depth direction from the surface of said carbon film, and a lubricant layer formed on said carbon film, which medium has improved running durability and corrosion resistance.

Magnetic recording medium having improved running time and corrosion

A glaze resistor composition composed of magnesium silicide, molybdenum disilicide, tantalum disilicide and glass frit, and if necessary, manganese disilicide and/or aluminum oxide. Due to the use of magnesium silicide, glaze resistors having stable resistivities in a wide resistivity range can be obtained. Due to the use of manganese disilicide, the temperature coefficient of resistivity can be shifted to the positive side, and due to the use of aluminum oxide, the resistivity can be increased and made more stable. This invention also provides a method of making a glaze resistor using two heating steps, in which aluminum oxide is mixed in the starting powder mixture to be subjected to the first heating step, so as to enhance the effect of the aluminum oxide addition.

Growing community of inventors

Ikoma, Japan

Kenji Kuwahara