Anionic microgel particle dispersion and a coating composition therefrom

A process for preparing an anionic micro gel particle dispersion comprising:

• (i) emulsifying in an aqueous medium a resin composition comprising
• (A) 100 parts by weight of an anionic film-forming aqueous resin, and
• (B) 10 to 250 parts by weight of a thermosetting crosslinking agent which is self-crosslinked or crosslinked with said aqueous resin (A) in terms of a condensation or addition reaction wherein the parts by weight are based on the solid content of the resin composition,
• provided that, when the aqueous resin (A) is selected from the group consisting of maleic natural or synthetic drying oil and maleic polybutadiene and a half-ester or half-amide thereof, the thermosetting crosslinking agent (B) is selected from the group consisting of methylolphenols, etherified methylolphenols and melamine resins, and when the aqueous resin (A) is an anionic acrylic resin, the thermosetting crosslinking agent (B) is selected from the group consisting of methylolphenols and etherified methylolphenols,
• (ii) and then heating the resultant emulsion to a temperature above the crosslinkable temperature of said crosslinking agent (B).