To provide an emulsion capable of being formed into a film even at about 2°C, although the emulsion does not contain a film-forming auxiliary agent at all or contains the agent in an extremely small amount, and capable of forming the film excellent in blocking properties at a high temperature and water resistance.

The ordinary-temperature-curing resin composition contains the multi-stage polymerized polymer emulsion and a hydrazide-based compound, wherein the polymer emulsion is formed by subjecting an ethylenic unsaturated monomer containing diacetone acrylamide to emulsion polymerization in an aqueous medium in processes of three or more stages and the total polymers polymerized in the processes have a glass transition temperature ([total] Tg) of 10-30°C as a whole.