Katayama Chemical Works Co., Ltd.

Yoshinari Kawasaki

Sakae Katayama

Sadaoki Kanada

Kazuo Marugame

Tadahiko Asano

Kenji Hanno

Toshihiko Mukai

Hirohiko Katayama

A method of anticorrosive treatment for soft water boilers to prevent iron family metals from corrosion, especially from pitting corrosion, which is characterized by adding, to a boiler water system using soft water at a high temperature, (a) a specific amount of a phosphorus compound, (b) a specific amount of a carboxylic acid compound and (c) a specific amount of a metal compound.

Method of anticorrosive treatment for soft water boilers

A corrosion inhibitor for ferrous metals comprising four different components of (a) an inorganic acid component (such as molybdate or tungstate), (b) an aliphatic hydroxycarboxylic or aliphatic dicarboxylic acid or its salt (such as citric acid, gluconic acid or succinic acid), (c) an inorganic heavy metal compound (such as zinc chloride or stannous chloride) and (d) a water soluble polymer component having a molecular weight of 500-100,000 (such as acylic homo or copolymer), which is especially advantageous for use in water recycling system.

Corrosion inhibitor

This invention relates to a scale inhibiting agent which comprises as an essential ingredient a copolymer of an alkylolamide compound such as N-methylol acrylamide, N-hydroxyethyl acrylamide or the like and an alkenyl compound such as acrylic acid, acrylamide, ethyl acrylate or the like.

Scale inhibiting agent

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Osaka, Japan

Yoshinari Kawasaki