PROCESS FOR THE PREPARATION OF RESINOUS COMPOUNDS, COMPOUNDS PRODUCED THEREBY AND THEIR USE IN THERMOSETTING COATING COMPOSITIONS

摘要

Carboxyl-containing resinous compounds, suitable for making water-dilutable thermosetting coating compositions after at least partial neutralization with a base, are prepared by a process wherein a non-acidic hydroxyl-containing resinous intermediate prepared by reacting at a temperature in the range 120 DEG to 180 DEG C. in the presence of an esterification catalyst in one or more steps (a) a diglycidyl ether of a dihydric phenol having an epoxy molar mass not exceeding 1100 with (b) a monofunctional phenol, and (c) dimerized unsaturated fatty acids in an epoxy phenolic or acidic equivalent ratio of (a), (b) and (c) from x/2/(x-2) to (x+0.1)/2/(x-2), wherein x is at least 4 for a diglycidyl ether having an epoxy molar mass from 400 to 1100 and x is at least 6 for a diglycidyl ether having an epoxy molar mass below 400, is reacted at a temperature not higher than 150 DEG C. with a carboxylic acid anhydride in an amount to produce a half-ester having an acid value in the range 15 to 80 mg KOH/g. Such resinous compounds when at least partially neutralized with a base and combined with a cross-linking compound are suitable for use in electrodeposition.