SCALE INHIBITOR FOR REVERSE OSMOSIS MEMBRANES AND REVERSE OSMOSIS MEMBRANE PROCESSING METHOD

摘要

A scale inhibitor for reverse osmosis membranes, which suppresses precipitation of calcium sulfate scale during a reverse osmosis membrane processing process, and which contains, as a main component, a copolymerized polymer (A) of an acrylic acid represented by formula (A) and 2-acrylamido-2-methylpropane sulfonic acid, said copolymerized polymer (A) having a mass average molecular weight of 3,000 or more but less than 11,000. It is preferable that the reverse osmosis membrane is processed with a sulfonic acid-modified polyvinyl alcohol in advance. In formula (A), m represents the ratio (mol%) of a constituent unit that is derived from 2-acrylamido-2-methylpropane sulfonic acid; n represents the ratio (mol%) of a constituent unit that is derived from acrylic acid; m is from 15 mol% to 40 mol% (inclusive); and (m + n) is from 90 mol% to 100 mol%.