Kao Corporation

Yuzo Yamamoto

Yumi Rakue

Hiromitsu Hayashi

Masaki Iwasaki

Akira Noda

Tsutomu Isobe

Kenji Kodama

Tomoyuki Haishi

Katsunori Nomoto

Toshiya Hagihara

Hiromoto Mizushima

Hiroyuki Nagamori

Manabu Shibata

Kozo Kitazawa

Michihide Yamauchi

Atsushi Ishikawa

Yoshiyuki Nabata

Koji Taira

Shinji Yamada

The present invention relates to an abrasive composition for substrates of magnetic recording media, containing at least an abrasive, an abrasive auxiliary and water. The abrasive auxiliary comprises an aliphatic organic sulfate, an oxyalkylene alkyl ether sulfate or an amphoteric surface active agent, and the abrasive composition has a pH of 1 to 13.

Abrasive composition for the base of magnetic recording medium and process for producing the base by using the same

The method for producing a magnetic recording medium, includes the steps of (a) subjecting surfaces of a substrate to grinding by a ductile-mode grinding with a grinding wheel having a setting depth of cut of from 0.05 to 20 .mu.m, to give a surface-worked substrate having grinding marks of arc patterns; and (b) forming recording medium-constituting layers at least comprising an under layer, a magnetic layer, and a protective layer on the surface-worked substrate, or on a mirror-polished substrate obtained by further subjecting the surface-worked substrate to a finish polishing. The resulting magnetic recording medium is constituted by (a) the surface-worked substrate or the mirror-polished substrate; and (b) recording medium-constituting layers at least comprising an under layer, a magnetic layer, and a protective layer, wherein the recording medium-constituting layers are formed on the surface-worked substrate, or on a mirror-polished substrate.

Magnetic recording medium and method for producing the same

A magnetic recording medium comprising a substrate having thereon at least a magnetic layer and a lubricant layer and a process for producing the same are disclosed, in which the lubricant layer is an uppermost layer and comprises a perfluoropolyether lubricant having a number average molecular weight of 800 to 30,000 and represented by formula (I):

Magnetic recording medium having a lubricant layer with a specified

An object of the present invention is to offer a magnetic recording medium comprising a substrate and a magnetic film formed on the substrate, wherein the substrate is formed using a conductive material and a surface of said substrate is processed by electroetching. As this magnetic recording medium has excellent surface characteristics, excellent durability and small spacing loss, its recording and play back characteristics are excellent.

Magnetic recording medium and manufacturing the same

A metal article is improved on its surface for the purpose of plating thereon by treatment with an additive of an anionic, cationic or amphoteric and water-soluble or water-self-dispersible organic polymer J, K or L. J is a polymer having an aromatic ring and OH group and a polar group. K is a polymer of hydroxystyrene having a polar group. L is a copolymer of hydroxystyrene having a polar group and a vinyl compound. The parted article is improved in corrosion resistance.

Metal surface treatment and aqueous solution therefor

An electrically conductive paste composition comprises an electrically conductive powder, a solvent and an organic binder comprising one or more monohydric phenol adduct compound selected from the group consisting of:

Electrically conductive paste and coating

The magnetic recording medium comprises a substrate, a recording coating of a ferromagnetic metal and an aromatic organic polymer having a weight-average molecular weight of 1,000 to 5,000,000. The magnetic recording medium is produced by a plating method or a vaporization method so as to form co-deposition of the metal and the polymer. The magnetic recording medium produced is improved in resistance to corrosion.

Process of making a magnetic recording medium

An electrically conductive paste composition comprises an electric conductive powder, an organic binder comprising (A) a polyhydroxystyrene derivative and (B) a thermosetting resin at a weight ratio of (A) to (B) in the range between 5/95 and 95/5 and a solvent. The paste is used for an electric circuit printed on a substrate and improved in view of migration resistance, flexibility and reliability.

Conductive paste and conductive coating film

An electrically conductive paste composition comprises an electrically conductive powder, an organic binder comprising a polymer of a hydroxystyrene having the formula (A) or a copolymer of hydroxystyrene having the formula (B), said polymer and copolymer each having a weight-average molecular weight of 1,000 to 2,000,000, and a solvent. In the formula, Y and Z are an amine group and others. ##STR1##

Electrically conductive paste composition

Magnetic recording medium

A metal article is improved on its surface for the purpose of plating thereon by treatment with an additive of an anionic, cationic or amphoteric and water-soluble or water-self-dispersible organic polymer J, K or L. J is a polymer having an aromatic ring and OH group and a polar group. K is a polymer of hydroxystyrene having a polar group. L is a copolymer of hydroxystyrene having a polar group and a vinyl compound. The article this way plated is improved in corrosion resistance.

Metal surface treatment with an aqueous solution

An electroplated composite coating of the invention which comprises 70 to 99.9 percent by weight of zinc or an alloy of zinc and 0.1 to 30 percent by weight of an organic polymer,

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Wakayama, Japan

Yuzo Yamamoto