An object is to provide an aqueous coating material composition having high viscosity expression property as well as a viscosity property of decreasing viscosity with increase in shear velocity; in particular, to provide an aqueous coating material composition that can form a multilayer coating film having excellent smoothness, clarity, flip-flop property, adhesion, and water resistance; in addition, to provide a method for forming a multilayer coating film using such aqueous coating material composition, as well as a coated article that has been coated with such aqueous coating material composition. As a solution, an aqueous coating material composition is provided that contains a polyester resin (A), acrylic resin particles (B), a curing agent (C), and a coloring pigment (D), wherein the polyester resin (A) is a resin containing a trifunctional or higher polyfunctional polycarboxylic acid (a1) and a polyol (a2) as monomer components.

To provide a paint composition capable of forming a coating film having a small graininess, having high flip-flop property, and having excellent chipping resistance and adhesion. According to the present invention, there is provided a paint composition including a hydroxy group-containing acrylic resin (A), a hydroxy group-containing polyester resin (B), an amino resin (C), and a titanium oxide-coated light interference pigment (D), which has an L*15 value of 100 or more and an L*110 value of 65 or less, wherein the solid content of the hydroxy group-containing acrylic resin (A) is in the range of 20 to 60 parts by mass, the solid content of the hydroxy group-containing polyester resin (B) is in the range of 10 to 50 parts by mass, the solid content of the amino resin (C) is in the range of 5 to 40 parts by mass, and the solid content of the titanium oxide-coated light interference pigment (D) is in the range of 3 to 25 parts by mass, relative to 100 parts by mass of the total solid content of the hydroxy group-containing acrylic resin (A), the hydroxy group-containing polyester resin (B), and the amino resin (C).

Provided herein is a method for producing a multicoat paint system on a metallic substrate by producing a basecoat or a plurality of directly successive basecoats directly on a metallic substrate coated with a cured electrocoat system, producing a clearcoat directly on the one or the topmost of the plurality of basecoats, and subsequently jointly curing the one or the plurality of basecoats and the clearcoat, wherein at least one basecoat material used for producing the basecoats includes at least one aqueous dispersion which includes a polymer whose preparation includes successive radical emulsion polymerization of three mixtures of olefinically unsaturated monomers.

Provided are a brilliant pigment-containing aqueous base coat coating material with which it is possible to ensure waterproof adhesiveness and impart a metallic gloss, and a method for forming a multilayer film using the same. The invention provides a brilliant pigment-containing aqueous base coat coating material including water-dispersible acrylic polymer particles (A), a water-soluble acrylic resin (B), a curing agent (C), and a brilliant pigment (D) obtained by pulverizing a vapor-deposited metal film to create metal chips. The water-soluble acrylic resin (B) is a copolymer of an N-substituted (meth)acrylamide (i), a hydroxyl group-containing polymerizable unsaturated monomer (ii), a carboxyl group-containing polymerizable unsaturated monomer (iii), and a polymerizable unsaturated monomer (iv) other than (i)-(iii). The brilliant pigment (D) is contained in a pigment weight concentration (PWC) in the range of 10-40%.

The present invention relates to a reaction product preparable by reacting (a) dimer fatty acids with (b) at least one compound (b) of the general structural formula (I)

##STR00001## where R is a C.sub.3 to C.sub.6 alkylene radical and n correspondingly is selected such that the compound (b) possesses a number-average molecular weight of 120 to 445 g/mol, components (a) and (b) are used in a molar ratio of 0.7/2.3 to 1.6/1.7, and the resulting reaction product possesses a number-average molecular weight of 600 to 4000 g/mol and an acid number of less than 10 mg KOH/g. The invention further relates to a pigmented aqueous basecoat material which comprises this reaction product, and to the use of the reaction product in pigmented aqueous basecoat materials for improving adhesion. The present invention further relates to a method for producing multicoat paint systems, and also to the multicoat paint systems producible by means of said method.

[Purpose] Among two-component top coat paints for the automobile coatings field, wherein the base resin paint is circulated from a main tank with a pump upstream of the coating gun, and mixing and coating are effected using a curing agent supplied from a nitrogen-sealed tank and a two-component mixing device, to provide a paint composition with which problems such as thickening and gelling of the circulating base resin paint do not occur, coating is possible with a stabilized constant coating viscosity, and with which the paint film after stoving exhibits excellent Scratch resistance, stain resistance, acid resistance and gasoline resistance, and a multilayer coating formation method using this. [Solution] The present invention provides a two-component paint composition which is applied directly after mixing a base resin and a curing agent, wherein the base resin (A) contains a hydroxy group-containing acrylic resin (A-1) and a curing catalyst (A-2) as essential components, the curing agent (B) contains an isocyanate Compound (B-1) and an alkoxysilyl group-containing copolymer (B-2) as essential components, the aforesaid hydroxy group-containing acrylic resin (A-1) has a hydroxyl value of 80 to 180 mg KOH/g, a glass transition temperature of ?40 to 40? C., and a weight average molecular weight of 2,000 to 20,000 g/mol, the aforesaid alkoxysilyl group-containing copolymer (B-2) is a copolymer obtained by copolymerizing 30 to 80 parts by weight of a vinylic monomer containing alkoxysilyl groups and 20 to 70 parts by weight of other copolymerizable monomers, its weight average molecular weight is 2,000 to 20,000 g/mol, and it does not contain hydroxy groups, carboxyl groups or amino groups which react with isocyanate groups.

A pigmented aqueous basecoat material is disclosed. The pigmented aqueous basecoat material includes a polyether-based reaction product which is preparable by a reaction of trimesic acid with at least one polyether of the general structural formula (I)

##STR00001##

R is a C.sub.3 to C.sub.6 alkylene radical and n is selected accordingly such that the at least one polyether possesses a number-average molecular weight of 500 to 5000 g/mol. The trimesic acid and the at least one polyether are used in the reaction in a molar ratio of 0.7/2.3 to 1.6/1.7 and the resulting reaction product possesses an acid number of 10 to 50 mg KOH/g.

The present invention relates to a process for producing a multicoat paint system on a metallic substrate, by producing a basecoat film or two or more directly successive basecoat films directly on a metallic substrate coated with a cured electrocoat system, producing a clearcoat directly on the one or the topmost of the two or more basecoat films, and then jointly curing the one or the two or more basecoat films and the clearcoat film, and which comprises at least one basecoat material used in producing the basecoat films comprising at least one aqueous polyurethane-polyurea dispersion (PD) comprising polyurethane-polyurea particles, with the polyurethane-polyurea particles present in the dispersion (PD) comprising anionic groups and/or groups which can be converted into anionic groups, and having an average particle size of 40 to 2000 nm and also a gel fraction of at least 50%.

A wet on wet process for multilayer coating of a substrate includes applying on the substrate to be coated a surfacer layer of an organic solvent-based surfacer coating composition comprising at least one polyaspartic acid ester, at least one polyisocyanate cross-linking agent with free isocyanate groups, at least one pigment and/or extender and at least one organic solvent. The surfacer layer on coated substrate is flashed off and a top coat layer is applied on the surfacer layer.

The invention relates to a method for producing a multi-layer coating structure, comprising the following steps: a) providing a substrate; b) applying at least one base-coat layer, wherein the base-coat layer is substantially free of melamine and derivatives thereof; c) applying at least one clear-coat and/or top-coat layer, comprising at least one polyisocyanate, at least one NCO-reactive compound, and at least one thermally latent catalyst; d) waiting for at least 30 s after step c) such that a film can form; e) curing the multi-layer coating structure while supplying heat. The invention further relates to the multi-layer coating structure that can be obtained from the method according to the invention, to the use of the multi-layer coating structure to coat substrates, and to substrates coated with the multi-layer coating structure.