Patent ID: 6861475

Claim:
A powder composition comprising one or more than one curable polymer or resin and an agglomerate of a core-shell polymer, wherein the agglomerate of a core-shell polymer has an average particle size of from 5 to 190 microns, further wherein, the said polymer or resin is chosen from epoxy resins, silicon-containing resins, vinyl ethers, oxetanes, oxolanes, cyclic acetals, cyclic lactones, thiiranes, thiotanes, or ultraviolet (UV) curable resins, still further wherein, when the said polymer or resin comprises UV curable resins, the said powder composition further comprises a photoinitiator, and yet still further wherein, when the said polymer or resin comprises epoxy resins, (i) the said epoxy resins comprise a mixture of an epoxy resin having an equivalent weight between 100 and 400 and one having an equivalent weight of between 400 and 700; (ii) the said epoxy resins further comprise a crystalline epoxy; (iii) the said powder coating composition further comprises an epoxy adduct of an aliphatic or aromatic polyamine or, alternatively, a combination of dicyandiamide and a substituted urea chosen from phenyl dimethyl urea, toluene bis dimethyl urea, methylene bis (phenyl dimethyl) urea, and cycloaliphatic bisurea, or (iv) the said powder coating composition further comprises an acidic matting agent.