The invention relates to interference pigments based on SiO.sub.2 flakes having a broad layer-thickness distribution, and to the use thereof in paints, coatings, powder coatings, plastics and in particular in cosmetic formulations and for colouring food and pharmaceutical products.

The present invention is directed to a chromatic effect light reflective unit (1; 1a-1g). The unit (1; 1a-1g) comprises a reflective layer (10) having at least one reflective surface (11), and a chromatic diffusion layer (20) having a first surface (21) proximal to the reflective surface (11) and a second surface (23), opposite and substantially parallel to the first, configured to be illuminated by incident light, wherein the chromatic diffusion layer (20) comprises a nano-pillar (70) or nano-pore (30) structure in a first material having a first refractive index (n1), immersed in a second material having a second refractive index (n2) other than the first (n1), in which the first and second materials are substantially non-absorbing or transparent to electromagnetic radiations with wavelength included in the visible spectrum, wherein the ratio (n.sub.M/n.sub.m) between a higher refractive index (n.sub.M) and a lower refractive index (n.sub.M) chosen between the first (n1) and the second (n2) refractive indexes is comprised between 1.05 and 3, wherein the nano- pillars (71) or nano-pores (31) have a development along a main direction not parallel to the first surface (21) and the second surface (23) of the chromatic diffusion layer and the nano- pillars (70) or nano-pores (30) structure is characterized by a plurality of geometric parameters comprising a pillar diameter or pore diameter (d.sub.p), a pillar length or pore length (1.sub.p) along said main development direction, and a surface density of nano-pillars or nano-pores (D.sub.p) and/or a structure (30,70) porosity (P.sub.p) and wherein the pillar diameter or pore diameter (d.sub.p) is comprised between 40 nm and 300 nm, the length (l.sub.p) along the main development direction is comprised between 300 nm and 40 .Math.m (300 nm < l.sub.p < 40 .Math.m) and at least one between the surface density of nano-pillars or nano-pores (D.sub.p) and the structure (30,70) porosity (P.sub.p) is configured to provide a higher regular reflectance for wavelengths of incident light comprised in the range of red with respect to wavelengths of incident light comprised in the range of blue and a higher diffuse reflectance for wavelengths of incident light comprised in the range of blue than wavelengths of incident light comprised in the range of red.

A method of making pigments, such as special effect pigment includes forming a first slurry including a substrate, a polymer precursor, and a radical initiator; forming a solution including an emulsifier; and combining the first slurry and the solution so that the substrate is encapsulated by a first coating. Special effect pigments formed by the method are also disclosed.

Effect pigments based on Al.sub.2O.sub.3 flakes with high weather resistance and less photoactivity and to their use thereof in paints, industrial coatings, automotive coatings, printing inks, cosmetic formulations. The effect pigments have a ratio of the amount by weight of Al.sub.2O.sub.3 of the Al.sub.2O.sub.3 flake and the amount by weight of the metal oxide(s) of the coating layer(s) in the range of from 27:73 to 83:17 based on the total weight of the effect pigment.

Effect pigments based on Al.sub.2O.sub.3 flakes with high weather resistance and less photoactivity and to their use thereof in paints, industrial coatings, automotive coatings, printing inks, cosmetic formulations. The effect pigments have a ratio of the amount by weight of Al.sub.2O.sub.3 of the Al.sub.2O.sub.3 flake and the amount by weight of the metal oxide(s) of the coating layer(s) in the range of from 27:73 to 83:17 based on the total weight of the effect pigment.

An effect pigment and process of making an effect pigment are provided. An exemplary effect pigment includes a substrate platelet and a coating. The coating includes at least one layer which has been wet-chemically prepared using a metal alkoxide and an organosilicon compound having a basic group.

This invention deals with effect pigment mixture comprising platelet-like aluminum effect pigments obtained by grinding of aluminum or aluminum based alloy shot and silvery pearlescent pigments, wherein the silvery pearlescent pigments are taken from the group consisting of: a) pearlescent pigments comprising a transparent substrate which is coated with a high-refractive index layer with n>1.8, which comprises or consists of an iron-oxide with Fe(II)-ions, b) pearlescent pigments comprising a transparent substrate which is coated with a high-refractive index layer with n>1.8, which comprises or consists of titanium suboxide or a pearlescent pigment comprising a substrate with a high-refractive index with n>1.8 layer, which comprises or consists of a titanium suboxide that is optionally coated with a high-refractive index layer with n>1.8, c) pearlescent pigments comprising a transparent substrate which is coated with a high-refractive index layer with n>1.8, which comprises or consists of titanium oxynitride, d) pearlescent pigments comprising a transparent substrate which is coated with a layer comprising carbon, wherein the carbon is enclosed in a particulate form in another metal oxide layer or is formed as a separate, individual layer, e) a transparent substrate coated with a first layer comprising or consisting of a mixture of the oxides of titanium, iron and at least one of cobalt and chromium and a second layer on the first layer, wherein the second layer comprises an oxide of titanium, and mixtures or combinations of the pearlescent pigments a) to e) or pearlescent pigments with mixtures or combinations of the various coating layers mentioned in the pearlescent pigments a) to e), wherein the weight ratio of the pearlescent pigment to the aluminum effect pigment is in a range of 0.4 to 5.0. The invention deals also with a coating formulation containing this effect pigment mixture.

The present invention relates to alumina flakes having a defined thickness and particle size distribution and to their use in varnishes, paints, automotive coatings, printing inks, masterbatches, plastics and cosmetic formulations and as substrate for effect pigments.

The present invention relates to alumina flakes having a defined thickness and particle size distribution and to their use in varnishes, paints, automotive coatings, printing inks, masterbatches, plastics and cosmetic formulations and as substrate for effect pigments.

This invention deals with effect pigment mixture comprising platelet-like aluminum effect pigments obtained by grinding of aluminum or aluminum based alloy shot and silvery pearlescent pigments, wherein the silvery pearlescent pigments are taken from the group consisting of: a) pearlescent pigments comprising a transparent substrate which is coated with a high-refractive index layer with n>1.8, which comprises or consists of an iron-oxide with Fe(II)-ions, b) pearlescent pigments comprising a transparent substrate which is coated with a high-refractive index layer with n>1.8, which comprises or consists of titanium suboxide or a pearlescent pigment comprising a substrate with a high-refractive index with n>1.8 layer, which comprises or consists of a titanium suboxide that is optionally coated with a high-refractive index layer with n>1.8, c) pearlescent pigments comprising a transparent substrate which is coated with a high-refractive index layer with n>1.8, which comprises or consists of titanium oxynitride, d) pearlescent pigments comprising a transparent substrate which is coated with a layer comprising carbon, wherein the carbon is enclosed in a particulate form in another metal oxide layer or is formed as a separate, individual layer, e) a transparent substrate coated with a first layer comprising or consisting of a mixture of the oxides of titanium, iron and at least one of cobalt and chromium and a second layer on the first layer, wherein the second layer comprises an oxide of titanium, and mixtures or combinations of the pearlescent pigments a) to e) or pearlescent pigments with mixtures or combinations of the various coating layers mentioned in the pearlescent pigments a) to e), wherein the weight ratio of the pearlescent pigment to the aluminum effect pigment is in a range of 0.4 to 5.0. The invention deals also with a coating formulation containing this effect pigment mixture.