SCALE INHIBITOR AND WATER TREATMENT AGENT FOR HIGH TEMPERATURE AND HIGH PRESSURE AQUEOUS SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a scale inhibitor having high safety to a human body or environment and capable of exhibiting scale preventing effect at high temp. under high pressure and a water treatment agent for a high temp. and high pressure aq. system exhibiting scale preventing and corrosion suppressing effect especially in a soft water boiler without using an oxygen scavenger such as hydrazine or a phosphate type corrosion inhibitor. SOLUTION: A scale inhibitor contains polyene polycarboxylic acid represented by formula (wherein n is an integer of 0-5 and m is an integer of 1 or 2), a deriv. in a carboxyl group thereof or a salt thereof. A water treatment agent for a high temp. and high pressure aq. system contains polyene polycarboxylic acid represented by the formula, a deriv. in a carboxyl group thereof or a salt thereof and a compd. discharging aliphatic oxycarboxylic acid ions in water.