Titanium dioxide pigments in thermosetting acrylic finishes

Over the last fifteen years, acrylic resins have become more widely accepted for use in surface coatings. Acrylic resins may be divided into two main categories, solvent‐borne and water‐borne systems. Solvent‐borne solution polymers may be subdivided into two groups: thermoplastic and thermosetting resins. Basically a thermosetting resin is built up from monomer units selected to give the degree of hardness and flexibility required. They may be self‐crosslinking, but usually require the addition of a crosslinking agent, a reactive bifunctional monomer unit, that serves to crosslink and insolubilize the copolymer. Other monomers may be introduced to confer specific properties and many commercial thermosetting acrylic resins contain four or more different units in the chain.