Hydroxy-functional lacquer formulations contain hardener-reactive organosilane surface-treated particles which increase the coating scratch resistance at low contents

摘要

A coating formulation contains particles (P) obtained by reacting a colloidal metal- or silicon-oxide sol with an organosilane, the formulation comprising the following components (a)-(c) by weight based on solids content and (d) as a percentage based on total formulation weight (A) a hydroxy group-functional lacquer resin (L) (20-90%); (B) a hardener (H) which contains optionally protected isocyanate groups or is a melamine-formaldehyde resin or a tri(aminocarbonyl)triazine (1-90%); (C) particles (P) having surface functions reactive with hardener (H) (0.05-5%); and (D) a solvent (mixture) (0-90%). A coating formulation contains particles (P) obtained by reacting a colloidal metal- or silicon-oxide sol with an organosilane of formula (R 1>O) 3-n(R 2>) nSi-A-X (I) or (II), the formulation comprising the following components (a)-(c) by weight based on solids content and (d) as a percentage based on total formulation weight (A) a hydroxy group-functional lacquer resin (L) (20-90%); (B) a hardener (H) which contains optionally protected isocyanate groups or is a melamine-formaldehyde resin or a tri(aminocarbonyl)triazine (1-90%); (C) particles (P) having surface functions reactive with hardener (H) (0.05-5%); and (D) a solvent (mixture) (0-90%). R 1>H, (cyclo)alkyl or aryl of 1-6C with the carbon chain optionally interrupted by non-adjacent O, S or NR 3>; R 2>H, (cyclo)alkyl, aryl or aralkyl of 1-12C with the carbon chain optionally interrupted as for R 1>; R 3>H, (cyclo)alkyl, aryl, aralkyl, aminoalkyl or an aspartate ester group; R 4>H or a suitable organic group; A : a divalent (cyclo)alkyl or aryl group of 1-10C with the carbon chain optionally interrupted as for R 1>; X : an organo-function able to chemically react with (H) during the hardening of the lacquer; Y : an organo-function able to chemically react with (H) (optionally after the splitting of the Si-Y bond) during the hardening of the lacquer; n and m : 0, 1 or 2; and q : 0 or 1. [Image].