GB762764A - Improvements in or relating to alkyd resins - Google Patents

Abstract

An epoxy modified alkyd resin suitable for use in coating compositions or as a plasticizer is the reaction product of (1) a dihydric alcohol (e.g. ethylene, diethylene, propylene, butylene or hexylene glycols, or a diether of pentaerythritol or a partial ester of glycerol or pentaerythritol and a fatty oil acid); (2) a dicarboxylic acid (e.g. phthalic acid and its isomers), adipic, succinic or Diels-Alder adducts of maleic and conjugated diolefins); (3) a fatty oil acid (e.g. stearic, oleic, palmitic, lauric, linseed, dehydrated castor, tobacco seed, sunflower seed, soya bean, tung or oiticica fatty acids); and (4) a condensation product in alkaline medium of epichlorhydrin and a dihydric phenol; the reactants having alcoholic hydroxyl groups in excess of the stoichiometric amount required to neutralize the carboxyl groups present (each epoxy group being considered as the equivalent of two hydroxyl groups). Unsaturated dicarboxylic acids (e.g. maleic) are preferably used only in conjunction with saturated acids (e.g. phthalic). In examples: (1) ethylene glycol, phthalic anhydride and linseed fatty acids were heated together to form a partial ester, a dihydric phenol-epichlorhydrin resin was added and heating continued. The resin which is compatible with butylated melamine-formaldehyde resins was thinned with xylol and butanol to yield a coating composition; (2) ethylene glycol, phthalic anhydride, linseed oil acids and a dihydricphenolepichlorhydrin condensate were heated together and the resulting resin mixed with a butylated melamine-formaldehyde resin to yield a stoving lacquer.