The invention relates to a composition including (i) at least one polyamide and at least one copolymer (A) of ethylene with at least one comonomer chosen from unsaturated carboxylic acids, esters of unsaturated carboxylic acids or vinyl esters of saturated carboxylic acids and (ii) being in powder form. These compositions are subsequently deposited on metal substrates and then a highly corrosion-resistant coating is obtained by melting.
The invention concerns to the use of a powder comprising 99.95 to 95% of at least one polyamide and 0.05 to 5% of at least one silane for coating metals. This powder may be prepared by simple dry blending of the constituents. The silane can also be added to the molten polyamide in a mixing device and the resulting product reduced to powder. The addition of silane makes it possible to significantly improve electrostatic application by preventing a substantial portion of the powder from falling off during the electrostatic discharge which follows application, while providing lasting adhesion between the coating and metal. Advantageously, the silane is chosen from aminopropyltriethoxysilane and aminopropyltrimethoxysilane. The invention also concerns a method of coating an object with a film resulting from melting a thin layer of the powder.
A curable coating composition which is based on a hydroxyl-functional binder and a blocked polyisocyanate, comprising a suspended finely divided, wax-coated polyamide. This composition exhibits a number of superior properties including having a greatly improved abrasion value.
The invention provides a powder coating composition in which powder particles are an agglomerate of individual particulate components fused or bonded together into composite particles. Maximizing the amount of larger-sized uncolored component(s) gives cost advantages, and the invention allows a rapid and flexible manufacture of a range of colored powder coating compositions.
