Fuji Electric Co., Ltd.

Fuji Electric Device Technology Co., Ltd.

Other

Fuji Electric., Ltd.

Youichi Tei

Shinichi Tamura

Akira Iso

Teruaki Kobayashi

Shinji Shirai

Seishi Terasaki

Tadashi Mimura

Hiroyuki Uwazumi

Hajime Kurihara

Kenichi Ohkura

Naoki Itoh

Kazumi Egota

Kazuhito Higuchi

Yoshimasa Hattori

Ryoji Kobayashi

Kazuo Nimura

Katsumi Onodera

Syoji Sakaguchi

Kengo Kainuma

Kouichi Tsuda

Yoshiharu Kashiwakura

Toshiyuki Kodaira

Michio Osawa

Yoshiaki Itoh

Michinori Nishimura

Takahiro Tokumoto

An object of the present invention is to provide a plating method on a glass base plate. The method allows forming a plating film on a base plate composed of a glass material with excellent adhesivity and homogeneity by means of an electroless plating method even to a thickness of 1 &#x3bc;m or more. Before forming a plating film by a step of electroless plating S, a surface treatment process is conducted on a surface of the base plate composed of a glass material. The surface treatment process comprises at least a step of glass activation treatment Sto increase quantity of silanol groups on the surface of the base plate at least by a factor of two using an aqueous solution of diluted acid, a step of silane coupling agent treatment S, a step of palladium catalyst treatment S, and a step of palladium bonding treatment S

Method of manufacturing a disk substrate for a magnetic recording medium

A disk substrate for a perpendicular magnetic recording medium is, disclosed. The substrate exhibits sufficient productivity, serves the function of a soft magnetic backing layer of the perpendicular magnetic recording medium, and scarcely generates noise. A perpendicular magnetic recording medium using such a substrate also is disclosed. The disk substrate comprises at least a soft magnetic underlayer formed on a nonmagnetic base plate by means of an electroless plating method. The thermal expansion coefficient of the soft magnetic underlayer is larger than a thermal expansion coefficient of the nonmagnetic disk-shaped base plate. A saturation magnetostriction constant &#x3bb;s satisfies a relation &#x3bb;s&#x2267;&#x2212;1&#xd7;10.

Disk substrate for a perpendicular magnetic recording medium and a perpendicular magnetic recording medium using the substrate

A method of plating on a glass substrate allowing an electroless plating film with good adhesiveness to be formed by chemically bonding a silane coupling agent in a state of simple adhesion or hydrogen bond to the surface of the glass substrate through dehydration condensation reaction, and a method of manufacturing a magnetic recording medium using the plating method. In the plating method, electroless plating is performed on a glass substrate after sequentially conducting at least the adhesion layer formation that forms an adhesion layer using a silane coupling agent solution, catalyst layer formation, a catalyst activation, and a drying that chemically bonds the silane coupling agent in the adhesion layer to the surface of the glass substrate.

Method of electroless plating on a glass substrate and method of manufacturing a magnetic recording medium using the method of electroless plating

A thermoplastic allyloxymethylstyrene-based resin comprising structural units of the following formulas (I) and (II): as repeating units, wherein R represents a hydrogen atom or a hydrocarbon group, and m and n each denote an integer of 0 or 1 or higher, provided that m and n are not 0 at the same time.

Thermoplastic allyloxymethylstyrene-based resin

An injection molded thermoplastic magnetic recording substrate a medium formed therewith, and a method thereof is composed of a thermoplastic or allyloxymethylstyrene type resin.

Magnetic recording medium substrate using thermoplastic allyloxymethylstyrene resin, magnetic recording medium using the substrate, and method of manufacturing the magnetic recording medium

A lubricant for a magnetic recording medium that imparts resistance to degradation, improved lubrication quality and better CSS durability to the medium, even when using a low levitating head. The lubricant is a perfluoropolyether compound having a cyclic triphosphazene end group within the molecule. A magnetic recording medium using at least one perfluoropolyether compound having a cyclic triphosphazene end group within the molecule as a lubricant. A method of making a magnetic recording medium which resists degradation when using a low levitation head including the sequential steps of: forming a foundation layer on a non-magnetic base, forming a magnetic layer on the foundation layer, forming a protection layer on the magnetic layer, and forming a lubrication layer on the protection layer. The lubrication layer includes at least one perfluoropolyether lubricant having a cyclic triphosphazene end group within the molecule.

Magnetic recording medium and method for manufacturing the same

To avoid troubles associated with high-density recording and fast transfer rate, such as decomposition of lubricant involved in a low floating height magnetic head and migration of lubricants involved in high speed rotation of a magnetic recording medium, and to provide a magnetic recording medium which achieves stable resistance to environment and stable lubricating characteristics, a magnetic recording medium includes a base body and the layers formed on the base body, including a non-magnetic metal underlayer, a magnetic layer, a protective layer, and a lubricant layer. The lubricant of the lubricant layer includes a perfluoropolyether liquid lubricant having an alcohol end group(s) and a perfluoropolyether liquid lubricant having an amine end group(s) of tertiary amine structure.

Magnetic recording medium and method for manufacturing same

A perfluoropolyether liquid lubricant is provided which has an amine functional group at at least one of ends of a chain molecule. A magnetic recording medium using the lubricant assures increased bonding force between a carbon protective layer and a lubricant layer.

Liquid lubricant, magnetic recording medium using the same, and method

A titanyloxyphthalocyanine crystal to be used as a charge generation material for an electrophotographic photoreceptor, having a maximum diffraction intensity observed at Bragg angle (2 .theta.) of 9.6.degree..+-.0.2.degree. and clear peaks of diffraction intensity observed at 7.22.degree..+-.0.2.degree., 9.60.degree..+-.0.2.degree., 11.60.degree..+-.0.2.degree., 13.40.degree..+-.0.2.degree., 14.88.degree..+-.0.2.degree.,18.34.degree..+-.0.2.degree., 23.62.degree..+-.0.2.degree., 24.14.degree..+-.0.2.degree., and 27.32.degree..+-.0.2.degree., respectively, in an X-ray diffraction spectrum obtained by performing an x-ray diffraction method using CuK.alpha. as a source of radiation. A method for preparing the crystal includes dispersing a predetermined amount of amorphous titanyloxyphthalocyanine in an aqueous solution in which ionic substances are dissolved, under mechanical force at a temperature of under 50.degree. C., to obtain a mixture composed of a fine dispersion of titanyloxyphthalocyanine; adding a non-aqueous organic solvent to the mixture to shift the fine dispersion of titanyloxyphthalocyanine from an aqueous phase to a non-aqueous organic solvent phase; and removing the non-aqueous organic solvent phase to obtain a pellet of titanyloxyphthalocyanine crystal.

Titanyloxyphthalocyanine crystals, and method of preparing the same

Phthalonitrile, an alkali metal or an alkali metal compound, and a hydrogen donor compound are heated in an organic solvent to synthesize a partially hydrogenated alkali metal phthalocyanine, which is then brought into contact with a dealkalizing agent to effect substitution with hydrogen of the partially hydrogenated alkali metal phthalocyanine to thereby obtain high-purity metal-free phthalocyanine. FX-type metal-free phthalocyanine as obtained according to the foregoing procedure may be used as a charge-generating substance to produce an electrophotographic photoconductor of high image quality which is highly sensitive to near infrared rays.

Process for preparing a metal-free phthalocyanine

An electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer including a charge generation material and a charge transport material. The charge generation material is a titanyloxyphthalocyanine crystal having a maximum diffraction intensity observed at Bragg angle (2.theta.) of 9.6.degree..+-.0.2.degree. and clear peaks of diffraction intensity observed at 7.22.degree..+-.0.2.degree., 9.60.degree..+-.0.2.degree., 11.60.degree..+-.0.2.degree., 13.40.degree..+-.0.2.degree., 14.88.degree..+-.0.2.degree., 18.34.degree..+-.0.2.degree., 23.62.degree..+-.0.2.degree., 24.14.degree..+-.0.2.degree., and 27.32.degree..+-.0.2.degree., respectively, in a X-ray diffraction spectrum obtained by performing a X-ray diffraction method using CuK.alpha. as a source of radiation, and having a lattice constant of:

Electrophotographic photoreceptors including titanyloxyphthalocyanine

A magnetic recording medium and a method for the manufacture thereof are disclosed that are less likely to result in head crushing even if high-hardness slider materials are used, and which is formed with a carbon protective layer that has good anti-CSS characteristics. The carbon protective layer is formed using a sputtering gas mixed with methane at a greater amount than predetermined to form a carbon protective layer in which diamond bonds are present at a higher ratio than graphite bonds, and polymeric bonds are present to an adequate degree. A magnetic recording medium having such a carbon protective layer shows a very high durability in a CSS cycle test.

Magnetic recording medium having an enhanced diamond bonding ratio and a

An electrophotographic photoconductor, includes metal-free phthalocyanine as a charge-generating substance, wherein the X-ray diffraction spectrum of said metal-free phthalocyanine as measured using CuK.alpha. as a radiation source includes intense diffraction peaks at Bragg angles (2.theta..+-.0.2.degree.) of 7.5.degree., 9.0.degree., 16.6.degree., 17.2.degree., 21.5.degree., 22.2.degree., 23.8.degree., and 28.5.degree., and wherein the infrared absorption spectrum of said metal-free phthalocyanine includes four absorption bands with the maximum absorption intensity at a wavenumber of 716 cm.sup.-1 between a wavenumber of 700 cm.sup.-1 and a wavenumber of 760 cm.sup.-1 and a characteristic absorption band at a wavenumber of 3,291.+-.2 cm.sup.-1.

Electrophotographic photoconductor including a metal-free phthalocyanine

Metal-free phythalocyanine, process for preparing the same, and

The quality of a lubricant layer formed on a surface of a magnetic recording medium is determined by exposing the lubricant molecules of the lubricant layer to a radiation source for x-ray photoelectron spectroscopy while varying the photoelectron drawing angle. The number of emitted electrons is determined and, from this, the degree of orientation and the quality of the lubricant layer is found.

Growing community of inventors

Nagano, Japan

Youichi Tei