| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyether which is hardly hydrolyzable and can easily be separated and removed in a waste water treatment by subjecting an OH- containing polyether to addition reaction with an epoxy group of an epoxidized fatty acid ester and saponifying the resultant intermediate product. SOLUTION: For example, the epoxidized fatty acid ester is one prepared by epoxidizing unsaturated bonds of a vegetable oil (a glyceride) containing unsatd, fatty acids in a high content (e.g. soy bean oil or linseed oil) or unsaturated bonds of a short-chain alkyl ester of an unsaturated fatty acid obtained from a vegetable oil with an epoxidizing agent (e.g. H2O2 or peracetic acid). An example of the OH-containing polyether is one prepared by the addition reaction of an alkylene oxide with a monool or a polyol. Therefore, the anionic polyether obtained by saponifying the intermediate product is obtained in the form of a carboxylic acid (salt), is not hydrolyzed even when used in an aqueous system, is precipitated as an insoluble metal salt by e.g. an alkaline earth metal, and hence can be easily separated and removed. |
