| abstract |
The invention relates to the use of 2-component coating systems as a primer for mineral substrates containing i) at least one free isocyanate prepolymer having a content of aliphatically bonded NCO groups of 12.5 to 17 wt -.%, Obtainable by reaction of aliphatic di or polyisocyanates having at least one polyoxyalkylene polyol obtainable by alkoxylation of hydroxy-functional starter molecules having an average hydroxyl functionality of 1.5 to 3 and an equivalent weight of at least 400 g / mol, and ii) at least one amino-functional polyaspartic acid ester of the general formula in which X is an n-valent organic radical which is obtained by removal of all the amino groups from a polyamine selected from the group consisting of 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane, 2,4-hexahydrotoluenediamine, 2, 6-hexahydrotoluenediamine, 2,4'-diamino-dicyclohexylmethane, 4,4'-diamino-dicyclohexylmethane, 3,3'-dimethyl-4,4'-diamino-dicyclohexymethane, 2,4,4'-triamino-5 methyl-dicyclohexylmethane or mixtures thereof is obtained, R 1 and R 2 independently of one another are a methyl or an ethyl group and n is an integer of at least 2. |