Adduct of a 2-substd.-4,6-diamino-s-triazine and isocyanuric acid of formula (I): (where R = 2-20C alkyl, unsubstd. or cyano-substd. aryl, or R1CH2CH2; R1 = 1-20C alkoxy, acyloxy, (N-substd.)amino, benzotriazolyl, 2-alkylimidazolyl-(4)-dithiocarbonyl, (where Z = -CH2CH2NHR2NHCH2CH2- R2 = -(CH2)m-(X)p-(CH2)m-m = 1 or 2; p = 0 or 1; and X = imino or phenylene is new. Synthesis of (I) is also claimed.
R of (I) is ethyl, n-propyl, n-hectadecyl or o-, m- or p-cyanophenyl or pref. R3NHCH2CH2-, where R3 is H, 1-18C monovalent hydrocarbyl, aminoalkyl, monovalent heterocyclyl or acyl. More specifically, R3 is alkyl, alkenyl, aralkyl, (alk)aryl or pyridyl acyl derived from (un)satd. carboxylic acid. If R is R1CH2CH2, then R1 is pref. acyloxy derived from (un)satd. carboxylic acid.
USE -(I) is used to cure epoxy resins for use as electronic encapsulants. Metal migration from the wiring circuit is prevented. A method of curing the epoxy resin is also claimed.