Powder coating compositions

A process for the preparation of a powder coating composition suitable for providing a coating having desired appearance or performance attributes, said process comprising the steps of:

• providing a primary film-forming component and one or more other, different, components selected from film-forming components and non-film-forming components,
• each said component consisting of solid particles and
• each particle of said primary film-forming component comprising a solid polymeric binder system at least a portion of which is a film-forming resin in an amount sufficient to impart film forming properties to the composition, the particles of said other, different, components containing at least one substance that, when processed into a coating with said primary film-forming component, provides with said primary film-forming component said desired appearance or performance attribute to said coatings, provided that, if the agglomerate contains a metallic or lustre component and a fluidisable film-forming component, it also contains an incompatible film-forming component or a non-film-forming performance component, or two or more such components, and
• comminuting the components and mixing and agglomerating them to produce composite particles such that the composition is air fluidisable and can be applied to a substrate by electrostatic spray and the individual particles in said composite particles are bonded together such that the composite particles do not break down under the mechanical and/or electrostatic forces associated with application of the composition to the substrate,
• wherein the identities, the particle sizes, and the proportions of the components mixed are such that, when applied to a substrate and heated to form a continuous coating, a film having the desired appearance or performance attribute is formed.