Provided is a water-borne coating composition capable of forming a metallic coating film having high-design, and further capable of forming a coating film that exhibits good coating film properties. A water-borne coating composition set for forming a multilayer coating film, containing a first base coating composition that forms a first base coating film and a second base coating composition that forms a second base coating film, wherein the first base coating composition contains a first coating film-forming resin, a first curing agent, a first inorganic brightener, and a first hydrophobic association rheology control agent, the first inorganic brightener contains one or more species selected from the group consisting of silica, talc, calcium carbonate, kaolin, barium sulfate, and diatomaceous earth, the second base coating composition contains a second coating film-forming resin, a second curing agent, a second luster material, a second inorganic rheology control agent, a second hydrophobic association rheology control agent, and a second dispersant, and the second inorganic rheology control agent contains a layered material having a stacked structure of a large number of inorganic crystal layers stacked.

The present invention relates to an aqueous polyurethane-polyurea dispersion (PD) having polyurethane-polyurea particles, present in the dispersion, having an average particle size of 40 to 2000 nm, and having a gel fraction of at least 50%, the polyurethane-polyurea particles comprising, in each case in reacted form, (Z.1.1) at least one polyurethane prepolymer containing isocyanate groups and comprising anionic groups and/or groups which can be converted into anionic groups, and (Z.1.2) at least one polyamine comprising two primary amino groups and one or two secondary amino groups, and the dispersion (PD) consisting to an extent of at least 90 wt % of the polyurethane-polyurea particles and water.

The present invention also relates to basecoat materials comprising the dispersion (PD), and to multicoat paint systems produced using the basecoat materials.

Disclosed herein is an aqueous coating composition including an anionically stabilized binder,a color pigment, a polycarboxylic acid, and optionally a solvent. Further disclosed is a method for producing an inventive aqueous coating composition by adding a solution of polycarboxylic acid in a solvent to a coating composition including an anionically stabilized binder and color pigment.Additionally disclosed is a method for producing a multicoat paint system by producing a basecoat layer or at least two directly consecutive basecoat layers directly on a substrate optionally coated with a first coating layer, producing a clearcoat layer directly on the basecoat layer or the topmost basecoat layer, and jointly curing the basecoat layer(s) and the clearcoat layer. At least one of the basecoat materials includes the aqueous coating composition disclosed herein and/or an aqueous coating prepared by the disclosed method. A multicoat paint system obtainable by the method is additionally disclosed.

A multi-layer coating system includes: a first basecoat layer formed from a first coating composition including a free polyisocyanate having a weight average molecular weight of less than 600 g/mol and hydroxyl functional polymeric core-shell particles, where an amount of free polyisocyanate having a weight average molecular weight of less than 600 g/mol is 3.5 weight % or greater; a second basecoat layer formed from a second coating composition including carboxylic acid functional polymeric core-shell particles; and a topcoat layer formed from a coating composition including a free polyisocyanate and a film-forming resin reactive with the free polyisocyanate.

A method for forming a multilayer coating film comprising the steps of: (1) applying a base paint (X) to a substrate to form a base coating film, (2) applying an effect pigment dispersion (Y) to the base coating film formed in step (1) to form an effect coating film, (3) applying a clear paint (Z) to the effect coating film formed in step (2) to form a clear coating film, and (4) heating the uncured base coating film, the uncured effect coating film, and the uncured clear coating film formed in steps (1) to (3) to thereby simultaneously cure these three coating films; wherein the effect pigment dispersion (Y) contains water, a black pigment (A), a vapor deposition metal flake pigment (B), and a rheology control agent (C).

The present disclosure is directed to a method for reactivating a co-cured film layer disposed on a composite structure, the method comprising applying a reactivation treatment composition comprising at least two solvents and a surface exchange agent comprising a metal alkoxide or chelate thereof to the co-cured film layer, and allowing the reactivation treatment composition to create a reactivated co-cured film layer, wherein the co-cured film layer was previously cured at a curing temperature greater than about 50° C. A reactivated co-cured film layer and an aircraft part having a reactivated co-cured film layer are also provided.

Provided is a method for forming a multilayer coating film.

The present invention relates to an aqueous polyurethane-polyurea dispersion (PD) having polyurethane-polyurea particles, present in the dispersion, having an average particle size of 40 to 2000 nm, and having a gel fraction of at least 50%, obtainable by (I) preparing a composition (Z) comprising based each case on the total amount of the composition (Z), (Z.1) 15 to 65 wt % of at least one intermediate containing isocyanate groups and having blocked primary amino groups, its preparation comprising the reaction (Z.1.1) of at least one polyurethane prepolymer containing isocyanate groups and comprising anionic groups and/or groups which can be converted into anionic groups, with (Z.1.2) at least one polyamine comprising at least two blocked primary amino groups and at least one free secondary amino group, by addition reaction of isocyanate groups from (Z.1.1) with tree secondary amino groups from (Z.1.2), (Z.2) 35 to 85 wt % of at least one organic solvent which possesses a solubility in water, of not more than 38 wt % at a temperature of 20° C., (II) dispersing the composition (Z) in aqueous phase, and (III) at least partly removing the at least one organic solvent (Z.2) from the dispersion obtained in (II), The present invention also relates to basecoat materials comprising the dispersion (PD), and to multicoat paint systems produced using the basecoat materials.

Provided is a method for forming a multilayer coating film including the following steps (1) to (4): (1) applying a base paint (X) to a substrate to form a base coating film; (2) applying a specific effect pigment dispersion (Y) to the base coating film formed in step (1) to form an effect coating film with a specific dry film thickness; (3) applying a clear paint (Z) to the effect coating film formed in step (2) to form a clear coating film; and (4) heating the uncured base coating film, the uncured effect coating film, and the uncured clear coating film formed in steps (1) to (3) to simultaneously cure these three coating films.

A method for forming a multilayer coated film includes step (1) of applying an aqueous intermediate coating composition (A), step (2) of applying an aqueous base coating composition (B), step (3) of applying a clear coating composition (C), and step (4) of heat-curing the coated films. The coating composition (A) contains a specific hydroxyl group-containing acrylic resin (a1), a specific polyurethane resin (a2), a specific hydroxyl group-containing polyester resin (a3), a melamine resin (a4), and an active methylene-blocked polyisocyanate compound (a5). A ratio of the resin (a1) to the resin (a2) falls within a specific range. The heat-cured coated film of the coating composition (A) has a specific elongation at break, Young's modulus and Tukon hardness. The coating composition (C) contains a hydroxyl group-containing acrylic resin (c1) and an allophanate group-containing polyisocyanate compound (c2).