Reactive fine particles

Reactive fine particles that are produced by a method that comprises:

• dissolving at least one latent curing agent selected from the group consisting of a urea derivative, an imidazole, a dicyandiamide (DICY), a mixture of any one or more thereof, and a precursor thereof, in at least one solvent to form a curing agent solution;
• and providing at least one inorganic inert particle comprising one or more members selected form the group consisting of a metal oxide, a mineral filler, a natural filler, and a mixture of any one or more thereof, the at least one inorganic inert particle having a specific surface area in the range of about 10 to about 50 m2/g;
• and precipitating the at least one latent curing agent onto the at least one inorganic inert particle to form reactive fine particles having a maximal particle size of less than 2 microns;
• wherein the at least one latent curing agent is entrapped, immobilized, encapsulated, soaked, doped or bonded into the inner portion of the at least one inorganic inert particle or the at least one latent curing agent is coated on the outer surface of the at least one inorganic inert particle, and a weight ratio of the at least one latent curing agent to the at least one inorganic inert particle is in a range of 0.01:100 to 50:100.