Toho Chemical Industry Co., Ltd.

Fujimi Incorporated

Takashi Tokuue

Takashi Kato

Hitoshi Kodama

Noritaka Yokomichi

Toshiki Owaki

Katsumi Tani

Tetsuya Sayama

Norio Fujioka

A polishing composition for a memory hard disc, which comprises the following components (a) to (d):

Polishing composition and rinsing composition

A process for quench hardening metal is provided. The process comprises heating the metal to a quench hardening temperature and thereafter immersing the metal in a quenching medium which is an aqueous solution containing 0.4 to 10% by weight of polyacrylic acid, polymethacrylic acid, a copolymer of acrylic acid and methacrylic acid, or a salt thereof. The process provides a perfect and uniformly hardened quenched structure and allows the production of a quenched structure having a desired degree of hardness.

Process for quench hardening with polyacrylate quenching medium

A novel quenching medium for steel is provided. The quenching medium is a 0.5-10 wt. % aqueous solution of polyacrylic acid, polymethacrylic acid, a copolymer of acrylic acid and methacrylic acid, or a salt thereof. Intrinsic viscosity [.eta.] of the polymer is from 0.010 to 0.050 l/g. The quenching medium is superior in various quenching characteristics to conventional quenching media.

Aqueous quenching medium containing salts of polymeric materials

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Yokohama, Japan

Takashi Tokuue