PURPOSE: To prevent the effect of a scale preventing material caused by an anticorrosive or the like used in combination from decreasing by using the scale preventing material consisting of a copolymer, containing a polyoxyalkylene compound expressed by a specific formula and maleic anhydride as an essential monomer and obtained by a prescribed solution polymerization or bulk polymerization, and the hydrolyzed compound or the salt.
CONSTITUTION: This scale preventing material consists of the copolymer containing the polyoxyalkylene compound (a) expressed by the formula and maleic anhydride (b) as a essential monomer and is obtained by the solution polymerization in a solvent inert to the acid anhydride group or the bulk polymerization in the absence of the solvent and the hydrolyzed compound or the salt. In the formula R1 is a 2-5C alkenyl group, R2 is a 1-4C hydrocarbon group, AO is a 2-4C oxyalkylene group in which oxyethylene group is 50-100mol% (n) is the average addition mol number and is 1-100. Where, the mol ratio of (a) to (b) is (3:7)-(7:3) and the number average molecular weight is 500-100000.
HONDA SUSUMU
KINOSHITA SEIGO
