Smooth, flexible powder coatings

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.