Epoxy resin and process for preparing the same
AssigneeKanegafuchi Kagaku Kogyo Kabushiki Kaisha
InventorsHaruo Tomita, Kazuya Yonezawa
Life of this patent
Estimating the term…
Abstract
An epoxy resin of the general formula: ##STR1## wherein X.sub.1 and X.sub.2 are --OH or ##STR2## and X.sub.3 is --OH, ##STR3## or a group of the general formula: ##STR4## in which X.sub.4, X.sub.5 and X.sub.6 are --OH or ##STR5## provided that at least one of X.sub.1 to X.sub.6 is ##STR6## The epoxy resin is prepared by reacting gallic acid or tannic acid with an epihalohydrin in the presence of a phase transfer catalyst and reacting the obtained reaction mixture with an aqueous alkali solution.
Claims4
An epoxy resin produced by reaction of gallic acid and an epihalohydrin in the presence of a phase transfer catalyst and in the substantial absence of water at 50.degree. to 110.degree. C., with the epihalohydrin being present in at least an equimolar amount to the molar amount of the total of carboxyl and hydroxyl groups of gallic acid and dehydrohalogenation of the resulting halohydrin ether and halohydrin ester moieties in an aqueous solution of an alkali metal hydroxide, with the amount of the alkali metal hydroxide being at least 1 times the molar amount of the total of hydroxyl groups and carboxyl group of the gallic acid, in the presence of said phase transfer catalyst at 20.degree. to 30.degree. C. to give a product mixture containing polyglycidyl compounds having the general formula:
- ##STR15## wherein X.sub.1, X.sub.2 and X.sub.3 are --OH or ##STR16## provided that at least one of X.sub.1 to X.sub.3 is ##STR17##
An epoxy resin produced by reaction of tannic acid and an epihalohydrin in the presence of a phase transfer catalyst and in the substantial absence of water at 50.degree. to 110.degree. C., with the epihalohydrin being present in at least an equimolar amount to the molar amount of the total of carboxyl and hydroxyl groups of tannic acid and dehydrohalogenation of the resulting halohydrin ether and halohydrin ester moieties in an aqueous solution of an alkali metal hydroxide, with the amount of the alkali metal hydroxide being at least 1 times the molar amount of the total of hydroxyl groups and carboxyl groups of the tannic acid, in the presence of said phase transfer catalyst of 20.degree. to 30.degree. C. to give a product mixture containing polyglycidyl compounds having the general formula:
- ##STR18## wherein X.sub.1, X.sub.2, X.sub.4, X.sub.5 and X.sub.6 are --OH or ##STR19## provided that at least one of X.sub.1, X.sub.2, X.sub.4, X.sub.5 and X.sub.6 is ##STR20##
Dependencies are inferred from the claim text.