SCRATCH RESISTANT ONE-PACK COATING MATERIAL

The present invention relates to a one-pack coating material, comprising a) at least one hydroxy-functional polymer (A) selected from the group consisting of (meth)acrylic polymers, polyesters and polyurethanes; b) at least one crosslinking agent (B) of general formula (I) being [R-(C=O)NH]zRorg wherein Rorg is an organic residue and z = 2 to 9 and R is selected from the group consisting of alkoxysilane groups containing groups of formulae (II) and (III) and isocyanate blocking groups, formula (II) being N[R1SiR3m(OR5)3-m][R2SiR4n(OR6)3-n] wherein R1 and R2 are independently from each other selected from linear, branched and cyclic alkylene groups having 1 to 10 carbon atoms, R3 and R4 are independently from each other selected from linear, branched and cyclic alkyl groups having 1 to 10 carbon atoms, R5 and R6 are independently selected from alkyl residues containing 2, 3 or 4 carbon atoms, and n and m are independently of each other 0, 1 or 2; and formula (III) being NR10[R7SiR8x(OR9)3-x] wherein R7 is selected from linear, branched and cyclic alkylene groups having 1 to 10 carbon atoms, R8 is selected from linear, branched and cyclic alkyl groups having 1 to 10 carbon atoms, R9 is selected from alkyl residues containing 2, 3 or 4 carbon atoms, R10 is selected from H and linear, branched and cyclic alkyl groups having 1 to 10 carbon atoms and x being 0, 1 or 2; and isocyanate blocking groups Rb being formally derived from isocyanate blocking agents of formula H-Rb by formal removal of H at the atom of residue Rb, which is bound to the carbon of the C=O group in formula (I); with the proviso that on average at least 15 mole-% of the entirety of residues R in formula (I) are residues of formula (II), and c) an aprotic organic solvent, wherein 2.0 to 30 wt.- % of the at least one crosslinking agent (B) are contained in the one-pack coating material, based on the total weight of the one-pack coating material. The invention further relates to a method for forming a coating on a substrate making use of the one-pack coating material, a thus coated substrate, a multilayer coating comprising a coating layer formed from the claimed coating material and a thus coated substrate. La présente invention concerne un matériau de revêtement monocomposant, comprenant a) au moins un polymère à fonctionnalité hydroxy (A) choisi dans le groupe constitué par des polymères (méth)acryliques, des polyesters et des polyuréthanes ; b) au moins un agent de réticulation (B) de formul