| abstract |
Powder coating compositions comprise a binder selected from carboxyl-group-containing polyesters, carboxyl-group-containing poly(meth)acrylates and mixtures of the said substances, and one or more epoxy compounds, wherein the epoxy compounds comprise at least one compound of formula (I) that is solid at 25° C.:whereinA corresponds to a group of formula (II), (IIl), (IV) or (VI): in whichB is an x-valent organic radical that is derived from a polyol having x or more hydroxyl groups by the removal of x hydroxyl groups;E is a (2x)-valent organic radical that is derived from a polyol having (2x) or more hydroxyl groups by the removal of (2x) hydroxyl groups; andD is a (y+2z)-valent radical that is derived from a polyol having (y+2z) or more hydroxyl groups by the removal of (y+2z) hydroxyl groups;R1 and R5 are each independently of the other hydrogen, halogen, C1-C4alkyl or C1-C4alkoxy or are together a methylene group; andR2, R3, R4, R6, R7, R8 and R9 are each independently of the others hydrogen, halogen, C1-C4alkyl or C1-C4alkoxy;x is an integer of at least 3;y is an integer from 1 to (x-1) andz is (x-y). |