Abstract: A process for producing an isocyanurate derivative of the formula (1): wherein one each of X1, X2, of Y1, Y2 and of Z1, Z2, a R COO group and the other is a OH group and each R is a C1-7 organic group, having an ionic chlorine atom content of from 0.1 to 5 ppm, which comprises reacting (A) tris-(2,3-epoxypropyl) isocyanurate containing from 10 to 3,000 ppm of hydrolyzable chlorine and (B) a carboxyl group-containing compound, in the presence of (C) an arylphosphine and/or a phosphonium salt comprising a non-halogen anion, until the concentration of the epoxy group in the reaction solution decreases to a 0.3 to 0.6 eq/kg, and then maintaining the reaction solution at 80 to 130° C. for H hours, where 0.2×2,5n≦H≦2×2.5n, where n=0.1(110−T), where T is the temperature (° C.), to bring the epoxy group concentration in the reaction solution to a level of less than 0.1 eq/kg.

Abstract: An epoxy/acid anhydride composition characterized by containing, as a curing accelerator, a substituted triazine of the formula [I] ##STR1## (wherein X is an amino group, C.sub.1-18 monoalkylamino group, di C.sub.1-18 alkylamino group, morpholino group, piperidino group, methyl group or phenyl group; R.sup.1 and R.sup.2 independently each represent C.sub.1-12 alkyl group, C.sub.1-12 hydroxyalkyl group, C.sub.4-8 cycloalkyl group, C.sub.5-9 cycloalkylmethyl group or C.sub.5-9 methylcycloalkyl group) in an epoxy/acid anhydride composition in which an epoxy compound and an acid anhydride-curing agent are contained, and an epoxy/acid anhydride resin composition prepared by thermosetting the epoxy/acid anhydride composition.

Abstract: .beta.-form tris-(2,3-epoxypropyl)-isocyanurate crystals containing from 2 to 15 wt % of .alpha.-form tris-(2,3-epoxypropyl)-isocyanurate in the interior of the crystals.

Abstract: A method for reducing an organic solvent remaining in tris-(2,3-epoxypropyl)-isocyanurate crystals, which comprises pulverizing crystal particles of tris-(2,3-epoxypropyl)-isocyanurate while evaporating a volatile component from the surface of the particles.

Abstract: A resin composition for powder coating, comprising(A) a carboxyl group-containing resin having a number average molecular weight of 1000 to 20000, an acid value of 5 to 200 and a glass transition temperature of 30 to 120.degree. C.,(B) bis(.beta.-methylglycidyl)terephthalate of the formula (1): ##STR1## as a curing agent, and (D) at least one compound selected from the group consisting of amines having the linkage of the formula (2): ##STR2## in the molecule, a triarylphosphines and onium salts as a ring-opening polymerization inhibitor, the equivalent ratio of (.beta.-methylglycidyl group of the component (B))/(carboxyl group of the component (A)) being 0.5 to 3.0. The composition can give a product of curing excellent in impact resistance, weathering resistance and so on.