Patent ID: 6770694
Filing Date: 2004-08-03
Classification: C09D

Abstract:
A powder coating composition for forming a multilayer film, obtained by dry blending a lower layer-forming thermosetting epoxy resin powder coating material (A) and an upper layer-forming thermosetting powder coating material (B) which is at least one member selected from thermosetting acrylic resin powder coating materials and thermosettmg polyester resin powder coating materials, the proportion of the material (A) to the material (B) being in the range of about 30 to 70 wt. % to about 70 to 30 wt. % based on the total weight of both materials, and the composition satisfying one of the following conditions (a) to (f):(a) (I) the material (A) contains an onium salt compound; (b) (II) particles of 45 &mgr;m or smaller diameter account for at least 90 wt. % of each of the materials (A) and (B); (c) (I) the material (A) contains an onium salt compound; and (II) particles of 45 &mgr;m or smaller diameter account for at least 90 wt. % of each of the materials A and B; (d) (I) the material (A) contains an onium salt compound; and (III) the material (A) is higher than the material (B) in melt viscosity (PaÂ·s) measured at 130Â° C.; (c) (II) particles of45 &mgr;m or smaller diameter account for at least 90 wt. % of each of the materials A and B; and (III)the matcrial (A) is higher than the material (B) in melt viscosity (PaÂ·s) measured at 130Â° C.; and (I) the material (A) contains an onium salt compound; (II) particles of 45 &mgr;m or smaller diameter account for at least 90 wt. % of each of the materials (A) and (B); and (III) the material (A) is higher than the material (B) in melt viscosity (PaÂ·s) measured at 130Â° C.