| abstract |
The present invention provides an aqueous coating composition containing a metal flake with improved glamour. This coating composition comprises a neutralized phosphorylated segment copolymer dispersed in an aqueous carrier. Phosphorus residues in the segment copolymer passivate metal flakes, such as aluminum flakes used to create a brilliance. As a result, the production of hydrogen gas is substantially reduced. Segment copolymers include hydrophobic segments and nonionic hydrophilic segments. Applicants have found that by including a nonionic hydrophilic segment in the segment copolymer, the brilliance of the resulting coating composition can be improved. In addition, the Applicant can adjust the molar ratio of the hydrophobic segment to the hydrophilic segment in the segment copolymer and adjust the solubility parameter of the hydrophobic segment so that the coating is improved in the state of brilliance compared to the conventional metal paint while maintaining the dispersion stability of the coating composition. It has been found that non-passivated aluminum flakes or pre-passivated aluminum flakes can be used in the composition. As a result, the manufacturer is substantially free to select various environmentally friendly solvents, film forming binders, and components commonly applied to the coating composition to improve coating properties. The composition is most suitable for use in automotive OEM and finish metal paints. |