| abstract |
Improved powder paint compositions providing greater depth variation of metal pigment particles comprise (1) aluminum flakes individually encapsulated in a thin, continuous, thermoplastic, organic film-former containing an ammonium salt selected from tetraalkyl ammonium halides and substituted tetraalkylammonium halides wherein at least one alkyl radical is replaced with an aryl, phenoxy, or alkoxy radical and (2) a particulate, organic film-former. The encapsulated aluminum flakes are prepared by intimately dispersing the aluminum flakes in a solution of the thermoplastic, organic film-former and the ammonium salt in a volatile solvent and spray drying the resultant dispersion. In the preferred embodiment, the particulate, organic film-former is also a thermoplastic material and, in the most preferred embodiment, it is of the same composition as the coating on the aluminum flakes. |