Described herein is a process for producing a multilayer coating (MC) on a substrate (S), the process including producing at least one basecoat layer, optionally at least one clearcoat layer, at least one layer including a mixture of glass flakes and at least one further clearcoat layer and jointly curing all applied layers. Also described herein is a multilayer coating obtained by the described process.

A clear coating method comprising: applying a clear paint on a topcoat base coating film (21) under a first coating condition, and thereby forming a first wet clear coating film in a first stage (14A); successively applying a clear paint on the first wet clear coating film under a second coating condition different from the first coating condition without baking the first wet clear coating film, and thereby forming a second wet clear coating film in a second stage (14B); and baking the first wet clear coating film and the second wet clear coating film and thereby forming a clear coating film, wherein a painted non-volatility value of the clear paint in the second stage is larger than a painted non-volatility value of the clear paint in the first stage, an average atomized paint particle size of the clear paint in the second stage is smaller than an average atomized paint particle size of the clear paint in the first stage, and a thickness of the second wet clear coating film is thinner than a thickness of the first wet clear coating film.

A multi-layer paint film satisfies paint film performance, such as water resistance, impact resistance and the like, required of an automobile paint film and which has excellent paint film appearance is obtained. The method comprises coating an aqueous first base paint (A) over an electrodeposited cured paint film to form a first base paint film, and then coating an aqueous second base paint (B) over the first base paint film without carrying out preliminary drying by heating after forming the first base paint film to form a second base paint film, preliminary drying by heating is carried out after forming the second base paint film, coating a single-liquid type clear paint (C) over the second base paint film to form a clear coat paint film. These three paint film layers are heated and cured at the same time.

Provided is a method for forming a multilayer coating film, the method being capable of forming a high-brightness white multilayer coating film which is excellent in terms of brilliant feeling, smoothness, and weather resistance and with which white stains are suppressed. In this method for forming a multilayer coating film to form a brilliant coating film, a white multilayer coating film is formed by: sequentially applying a first coloring paint (P1), a second aqueous coloring paint (P2), a third aqueous coloring paint (P3), and a clear coat paint (P4) on a cured electrodeposition coating film formed on a steel sheet; and forming a first colored coating film, a second colored coating film, a third colored coating film, and a clear coat coating film which each have a particular composition, brightness, film thickness, and the like.

Provided is a method for forming a multilayer coating film, comprising simultaneously curing an uncured base coating film, an uncured effect coating film, and an uncured clear coating film. In this method, an effect pigment dispersion (Y) that forms the effect coating film contains water, a surface adjusting agent (A), a flake-effect pigment (B), and a rheology control agent (C), and has a solids content of 0.5 to 10 mass %.

A paint composition contains (A) a binder component, (B) a first rheology control agent, and (C) a second rheology control agent, wherein the first rheology control agent (B) contains a reaction product of (b1) a polyisocyanate compound, (b2) a primary monoamine having a number average molecular weight of 300 or less, and (b3) a polyether amine having a number average molecular weight of more than 300 and less than 6000; the proportion of the polyether amine having a number average molecular weight of more than 300 and less than 6000 (b3) is 0.5 mass % or more and less than 10 mass % based on the total amount of the components (b1) to (b3); the second rheology control agent (C) contains a reaction product of (c1) a polyisocyanate compound, (c2) a primary monoamine having a number average molecular weight of 300 or less, and (c3) a polyether amine having two or more amino groups and having a number average molecular weight of 1000 or more and less than 6000; and the proportion of the polyether amine having two or more amino groups and having a number average molecular weight of 1000 or more and less than 6000 (c3) is within a range of 10 to 30 mass % based on the total amount of the components (c1) to (c3).

The present invention provides a coating composition capable of forming a coating film having a good appearance and design of a coating film and having coating film properties such as scratch resistance with a good balance. Furthermore, the present invention provides a method for forming a multilayer coating film including forming a coating film using the coating composition of the present invention.

A method for forming a multilayer coating film comprising the steps of: applying, to a substrate, an effect pigment dispersion that comprises water, a surface adjusting agent, a flake-effect pigment, and a rheology control agent, and that has a solids content within the range of 0.5 to 10 mass % to form an effect pigment-containing coating film; and applying a colored transparent paint to the effect pigment-containing coating film to form a colored transparent coating film having a total light transmittance at a wavelength of 400 nm to 700 nm of 20 to 70%.

The present invention provides a coating composition capable of forming a coating film having a good appearance and design of a coating film and having coating film properties such as scratch resistance with a good balance. Furthermore, the present invention provides a method for forming a multilayer coating film including forming a coating film using the coating composition of the present invention.

A vehicle body part including a support, an uncured sealer and an uncured primer, the uncured sealer being interposed between the support and the uncured primer, the uncured sealer and the uncured primer each including a compatible solvent, each compatible solvent having a log P.sub.ow value and an absolute value of a difference between the log P.sub.ow value of the compatible solvent of the uncured primer and the compatible solvent of the uncured sealer being equal to or smaller than 3.0. A method of forming a finished vehicle body part.