Blocked polyisocyanate crosslinkers for providing improved flow properties to coating compositions

A powder coating composition containing as binder

• A) a polyisocyanate component which contains blocked isocyanate groups, is present in powder form, is solid below 40.degree. C. and liquid above 150.degree. C., and contains one or more polyisocyanates
• i) having a blocked NCO content (calculated as NCO, MW 42) of 5 to 25% by weight of (cyclo)aliphatically-bound isocyanate groups and
• ii) containing fluorine (calculated as F, AW 19) in an amount of 0.02 to 10% by weight,
• wherein the preceding percentages are based on the solids content of the polyisocyanate mixture and wherein fluorine is incorporated into said polyisocyanate component by reacting a polyisocyanate with a compound containing two or more carbon atoms, one or more hydroxyl groups and two or more fluorine atoms in the form of --CF.sub.2 -- groups, and
• B) a polyhydroxyl component comprising one or more high molecular weight polyols.

A powder coating composition containing as binder

• A) a polyisocyanate component which contains blocked isocyanate groups, is present in powder form, is solid below 40.degree. C. and liquid above 150.degree. C., and contains one or more polyisocyanates
• i) having a blocked NCO content (calculated as NCO, MW 42) of 5 to 25% by weight of (cyclo)aliphatically-bound isocyanate groups and
• ii) containing fluorine (calculated as F, AW 19) in an amount of 0.05 to 7% by weight,
• wherein the preceding percentages are based on the solids content of the polyisocyanate mixture and wherein fluorine is incorporated into said polyisocyanate component by reacting a polyisocyanate with a compound containing two or more carbon atoms, one hydroxyl group and two or more fluorine atoms in the form of --CF.sub.2 -- groups, and
• B) a polyhydroxyl component comprising one or more high molecular weight polyols.