Patent ID: 8211330

Claim:
A method for manufacturing a latent curing agent for an epoxy resin, the latent curing agent for the epoxy resin comprising particles of an adduct of an epoxy-based compound and an imidazole-based compound, and an ethyl cellulose film crosslinked with a polyfunctional isocyanate compound, the cross-linked ethyl cellulose film covering surfaces of the adduct particles, the method comprising: dissolving the epoxy-based compound, the imidazole-based compound, and ethyl cellulose in which the degree of substitution of three hydroxyl groups in a cellulose skeleton of the ethyl cellulose is 2.25 to 2.60, in a saturated hydrocarbon-based solvent having an aniline point of 75 to 85° C. and an initial boiling point of 150 to 230° C. under stirring at a heating temperature of 110 to 130° C.; forming the adduct of the epoxy-based compound and the imidazole-based compound to obtain a slurry of the adduct particles; cooling the slurry of adduct particles to a temperature of 80 to 100° C.; and following the cooling, adding a polyfunctional isocyanate compound and allowing the polyfunctional isocyanate to cross-link the ethyl cellulose to form the cross-linked ethyl cellulose film on the surface of the adduct particles.