A difference between a peak reflectance of a first wavelength component and a reflectance of a second wavelength component having a predetermined wavelength among reflectances of a plurality of wavelength components constituting reflected light in a highlight direction from a glitter material-containing coating film is set as a first difference value. Reflectance is measured of the first and second wavelength components of the reflected light in the highlight direction for the coating film corresponding to a measurement object. A first difference value is calculated by using the measurement result. A storage stores in advance correlation information indicating a correlation between the first difference value and an index value indicating predetermined physical characteristics of a glitter material contained in the coating film. An index value calculator calculates the index value of the coating film corresponding to the measurement object by using the correlation information and the first difference value calculated in the first calculator.

The present invention provides a glitter pigment suitable for imparting high brightness to reflected light toward a regular reflection direction and reducing unnaturalness caused by an observation angle-dependent variation in reflected light. The glitter pigment according to the present invention includes: a flaky substrate; an optical interference film formed on a surface of the flaky substrate; and fine light scattering particles attached to the optical interference film, wherein reflected light is represented by an L*(15) value of more than 100, a L*(hs) value of less than 30, and a h(hs) value of less than 40 in an L*C*h color system. The L*(15) value is an L* value of the reflected light toward a 15 direction based on an angular representation in which, when an illuminant is disposed so that an incident angle is 45, an angle at which light is regularly reflected is defined as 0 and a light incident direction is defined as positive. The L*(hs) value is a difference in L* between a highlight and shade, and the h(hs) value is a difference in h between a highlight and shade. The h value expressed in angle is an angular difference. The highlight is an average of values measured at 15 and 25, and the shade is an average of values measured at 75 and 110.

Described herein are an aqueous effect pigment paste including at least one effect pigment (a) and at least one polymer (b) which is preparable by successive radical emulsion polymerization of three monomer mixtures (A), (B) and (C) of olefinically unsaturated monomers in water, an aqueous basecoat material which is preparable by admixing the effect pigment paste to at least one aqueous binder-containing component suitable for preparing the basecoat material, a method for producing a multicoat paint system using this basecoat material, and use of the polymer (b) for dispersing effect pigments within an aqueous effect pigment paste.

Described herein are an aqueous effect pigment paste including at least one effect pigment (a) and at least one polymer (b) which is preparable by successive radical emulsion polymerization of three monomer mixtures (A), (B) and (C) of olefinically unsaturated monomers in water, an aqueous basecoat material which is preparable by admixing the effect pigment paste to at least one aqueous binder-containing component suitable for preparing the basecoat material, a method for producing a multicoat paint system using this basecoat material, and use of the polymer (b) for dispersing effect pigments within an aqueous effect pigment paste.

The present invention relates to a solid solution comprising (a) at least one compound according to formula (I) and (b) at least one compound according to formula (II), or at least one compound according to formula (III), or a mixture of at least one compound according to formula (II) and at least one compound according to formula (III) wherein R.sub.1 and R.sub.2 may, independently of one another, stand for (CH.sub.2).sub.nX, wherein X stands for hydrogen, methyl, a C.sub.1-C.sub.5 alkoxyl, hydroxy, phenyl, C.sub.1-C.sub.5 alkylphenyl, C.sub.1-C.sub.5 alkoxyphenyl, hydroxyphenyl, halogenated phenyl, pyridyl, C.sub.1-C.sub.5 alkylpyridyl, C.sub.1-C.sub.5 alkoxypyridyl, halogenated pyridyl, pyridylvinyl or naphthyl; wherein n stands for 0, 1, 2, 3, 4 or 5; R.sub.3 and R.sub.4 may, independently of one another, stand for phenylene, C.sub.1-C.sub.5 alkylphenylene, C.sub.1-C.sub.5 alkoxyphenylene, hydroxyphenylene, halogenated phenylene, pyridinediyl, C.sub.1-C.sub.5 alkylpyridinediyl, C.sub.1-C.sub.5 alkoxy-pyridinediyl, halogenated pyridinediyl, anthraquinonediyl or naphthalenediyl, wherein the 2 nitrogen atoms bound to R.sub.4 according to formula (II) and (III) form a 5-membered or a 6-membered heterocycle with 2 atoms of an aromatic ring of R.sub.3; wherein the 2 nitrogen atoms bound to R.sub.4 according to formula (II) and (III) form a 5-membered or a 6-membered heterocycle with 2 atoms of an aromatic ring of R.sub.4; X.sub.1 to X.sub.8 may, independently from one another, stand for hydrogen, C.sub.1-C.sub.5 alkyl, C.sub.1-C.sub.5 alkoxy, hydroxy, phenyl or halide. The present invention further relates to a process for producing the solid solution. Furthermore, the present invention relates to a solid solution obtainable or obtained according to said process and to the use of the inventive solid solution, in particular as a NIR transparent black colorant in a NIR non-absorbing component.

##STR00001##

The present invention relates to a solid solution comprising (a) at least one compound according to formula (I) and (b) at least one compound according to formula (II), or at least one compound according to formula (III), or a mixture of at least one compound according to formula (II) and at least one compound according to formula (III) wherein R.sub.1 and R.sub.2 may, independently of one another, stand for (CH.sub.2).sub.nX, wherein X stands for hydrogen, methyl, a C.sub.1-C.sub.5 alkoxyl, hydroxy, phenyl, C.sub.1-C.sub.5 alkylphenyl, C.sub.1-C.sub.5 alkoxyphenyl, hydroxyphenyl, halogenated phenyl, pyridyl, C.sub.1-C.sub.5 alkylpyridyl, C.sub.1-C.sub.5 alkoxypyridyl, halogenated pyridyl, pyridylvinyl or naphthyl; wherein n stands for 0, 1, 2, 3, 4 or 5; R.sub.3 and R.sub.4 may, independently of one another, stand for phenylene, C.sub.1-C.sub.5 alkylphenylene, C.sub.1-C.sub.5 alkoxyphenylene, hydroxyphenylene, halogenated phenylene, pyridinediyl, C.sub.1-C.sub.5 alkylpyridinediyl, C.sub.1-C.sub.5 alkoxy-pyridinediyl, halogenated pyridinediyl, anthraquinonediyl or naphthalenediyl, wherein the 2 nitrogen atoms bound to R.sub.4 according to formula (II) and (III) form a 5-membered or a 6-membered heterocycle with 2 atoms of an aromatic ring of R.sub.3; wherein the 2 nitrogen atoms bound to R.sub.4 according to formula (II) and (III) form a 5-membered or a 6-membered heterocycle with 2 atoms of an aromatic ring of R.sub.4; X.sub.1 to X.sub.8 may, independently from one another, stand for hydrogen, C.sub.1-C.sub.5 alkyl, C.sub.1-C.sub.5 alkoxy, hydroxy, phenyl or halide. The present invention further relates to a process for producing the solid solution. Furthermore, the present invention relates to a solid solution obtainable or obtained according to said process and to the use of the inventive solid solution, in particular as a NIR transparent black colorant in a NIR non-absorbing component.

##STR00001##

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) contains water, a rheology control agent (A), and a flake-effect pigment (B), and has a solids content of 0.5 to 10 mass %; the flake-effect pigment (B) is an interference pigment in which a transparent or translucent base material is coated with a metal oxide; and the flake-effect pigment (B) is contained in an amount of 30 to 90 parts by mass based on 100 parts by mass of the total solids content in the effect pigment dispersion (Y).

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) contains water, a rheology control agent (A), and a flake-effect pigment (B), and has a solids content of 0.5 to 10 mass %; the flake-effect pigment (B) is an interference pigment in which a transparent or translucent base material is coated with a metal oxide; and the flake-effect pigment (B) is contained in an amount of 30 to 90 parts by mass based on 100 parts by mass of the total solids content in the effect pigment dispersion (Y).

A multilayer coating film forming method to form a multilayer coating film having a glittering appearance. Forming a multilayer coating film by sequentially applying, on top of a base material, a first base coating material, a second base coating material, and a clear coating material in a wet-on-wet process, wherein: the first base coating material is a transparent or colored coating material; the second coating material contains a flaky lustrous pigment; the amount of flaky lustrous pigment being 10-60 parts by mass to 100 parts by mass of resin solid content in the second base coating material, and the concentration of solids in the coating falls being 5-20 mass % with respect to the total mass of the second base coating material; and the thickness of a coating film obtained from the second base coating material falls being 1-8 m on the basis of the coating film when cured.

A multilayer coating film forming method to form a multilayer coating film having a glittering appearance. Forming a multilayer coating film by sequentially applying, on top of a base material, a first base coating material, a second base coating material, and a clear coating material in a wet-on-wet process, wherein: the first base coating material is a transparent or colored coating material; the second coating material contains a flaky lustrous pigment; the amount of flaky lustrous pigment being 10-60 parts by mass to 100 parts by mass of resin solid content in the second base coating material, and the concentration of solids in the coating falls being 5-20 mass % with respect to the total mass of the second base coating material; and the thickness of a coating film obtained from the second base coating material falls being 1-8 m on the basis of the coating film when cured.