| 摘要 |
1,207,793. Modified epoxy resins. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. 6 Jan., 1969, No. 795/69. Heading C3B. [Also in Divisions C6-C7] Water thinnable resins are prepared by a three-stage process: (i) a polyglycidyl ether of a polyhydric phenol (I) is reacted with rosin acids in a ratio of from 0.5 to 1À0 acid equivalents per epoxy equivalent of the glycidyl ether; (ii) the hydroxyl groups of the product of step (i) are esterified by ethylenically unsaturated fatty acids, (II) in a ratio of 0À8-1À2 acid equivalents per hydroxy equivalent of the rosin acid ester; and (iii) the resultant polyester is reacted with at least 4% by wt. of an ethylenically unsaturated polycarboxylic acid, (III) or an anhydride thereof. I may be a polyglycidyl ether of bisphenol A having an epoxide equivalent of 170-1200. II preferably contains more than one ethylenic group per molecule, e.g. drying oil acids. III is preferably maleic anhydride. Each of the reactions may be carried out in the presence of an esterification catalyst. Step (iii) may be performed at > 175‹ C. At least 40% of the carboxyl groups of the condensate may be neutralized, e.g. with ammonia or an organic nitrogen base. A lyotropically active solvent, e.g. ethylene glycol monobutyl ether may be added to the condensate (or neutralized condensate) when forming a coating composition. Conventional pigments may be present. The resultant compositions may be used in electrodeposition processes. |
