| abstract |
FIELD: chemistry.SUBSTANCE: present invention relates to a multilayer coating system, as well as a substrate coated with a multilayer coating, and a method of coating a substrate with a multilayer coating. Multilayer coating system comprises: (a) a first base coating layer, (b) a second base coating layer applied over at least a portion of the first base coating layer, and (c) a topcoat layer applied over at least a portion of the second base coat layer. First coating layer is formed from the first coating composition containing free polyisocyanate and polymer core-shell particles with hydroxyl functional groups. Polymer core and the polymer shell of the core-shell particles with hydroxyl functional groups each independently contain an additive polymer formed from ethylenically unsaturated monomers. Second coating layer is formed from the second coating composition containing polymer core-shell particles with carboxylic acid functional groups. Polymer core of core-shell particles with carboxyl acid functional groups contains an additive polymer formed from ethylenically unsaturated monomers, and the polymer shell of said particles contains urethane bonds and carboxylic acid functional groups. Topcoat layer is formed from a coating composition containing at least one free polyisocyanate having a weight average molecular weight of less than 600 g/mol, and at least one film-forming resin, wherein the amount of free polyisocyanate having a weight-average molecular weight of less than 600 g/mol is more than 5 wt. % based on the total weight of the solid polymer substances in the coating composition which forms the top coating layer.EFFECT: present invention provides for creation of multilayer coatings, which can be dehydrated and cured at relatively low temperatures with formation of coatings having different properties, thereby reducing costs and increasing efficiency of coating processes.21 cl, 7 tbl, 26 ex |