Patent ID: 8147720

Claim:
A thermosetting composition comprising: a silane coupling agent; a thermosetting compound; and an aluminum chelate-based latent curing agent being made latent by reacting a silsesquioxane-type oxetane derivative with an aluminum chelating agent in the presence of an alicyclic epoxy compound and in the absence of ethyl cellulose, wherein an amount of the silsesquioxane-type oxetane derivative is in a range of 0.1 to 500 parts by weight with respect to 100 parts by weight of the aluminum chelating agent, and an amount of the alicyclic epoxy compound is in a range of 0.1 to 1,000 parts by weight with respect to 100 parts by weight of a total amount of the aluminum chelating agent and the silsesquioxane-type oxetane derivative; wherein the aluminum chelate-based latent is present in an effective amount such that the curing of the thermosetting composition can be initiated at a low temperature, and the thermosetting composition has an exothermic onset temperature in a range of 78.1 to 95.3° C. and an exothermic peak temperature in a range of 106.6 to 120.9° C.