EP1633819A1

EP1633819A1 - Photostabilised effect pigments

Info

Publication number: EP1633819A1
Application number: EP04729647A
Authority: EP
Inventors: Ulrich Schoenefeld; Padma Kaviratna
Original assignee: Merck Patent GmbH
Current assignee: Merck Patent GmbH
Priority date: 2003-05-21
Filing date: 2004-04-27
Publication date: 2006-03-15
Also published as: KR20060028392A; US7455726B2; CN1791645A; JP2007505987A; CN100384946C; WO2004104110A1; US20070060668A1

Abstract

The invention relates to photostabilised effect pigments, at least one calcinated oxide layer containing vanadium being applied to a substrate, individually or mixed with sulfates, borates or phosphates. The invention also relates to methods for producing said effect pigments, and to the use of the same in plastics, lacquers, paints, printing inks, cosmetics, and films, in security printing, laser marking, thermal insulation or seed pigmentation.

Description

Photo-stabilized effect pigments

The present invention relates to photostabilized effect pigments, one or more calcined and vanadium-containing oxide layers being applied to a substrate, alone or in a mixture with sulfates, borates or phosphates, processes for their preparation and their use in plastics, paints, paints, printing inks, cosmetics , Foils, in security printing, for laser marking, in heat protection or for seed coloring.

Plastic parts and layers of paint for outdoor applications are often exposed to extreme weather conditions and long-lasting intense light, which leads to an aging of the materials. This manifests itself in discoloration, embrittlement and reduced mechanical and chemical stability. The causes for this are oxidative or photolytic decomposition of the binders or decomposition by the action of water in liquid form or water vapor. In addition, the pigments used, in particular pearlescent pigments containing titanium oxide layers, can also impair the resistance of the application media to the effects of light and weather. The reason for this is the special photoactivity of titanium dioxide layers, which accelerates the photolytic decomposition of the organic components of the application medium.

In order to inhibit these aging processes, formulations for outdoor applications, stabilizers, for example UV light-absorbing substances, are added. Furthermore, the pigments can be provided with additional inorganic layers. For example, WO 98/58017 describes a composition containing a polyolefin, an antioxidant and a pearlescent pigment which is said to show a lower tendency to yellowing. The antioxidant is an essential component of the mixture, which limits the applicability in application media, since the antioxidant has to be adapted to the other application components in order to avoid destruction of these compounds in the applications.

It has long been known to increase the photostability of titanium dioxide pigments by adding dopants. For example, DE 2407429 describes the precipitation of vanadium compounds on titanium dioxide pigment suspensions, whereby the pigment must under no circumstances be calcined in order to avoid the formation of colored compounds or darkening of the pigment. Uncalcined pigments are characterized by their lower stability, which is particularly important in applications with a long service life, e.g. Varnishes or plastics, is a disadvantage.

DE 2 545 243 describes a method for producing a titanium dioxide pigment with increased photochemical stability by adding water-containing titanium dioxide to metal ions from the group of vanadium, copper and / or manganese and then calcining at 600 to 1100 ° C. This process is limited to pure titanium dioxide pigments, which limits the range of applications for paints, varnishes or plastics.

It was therefore an object to provide photostabilized effect pigments with improved application properties, which can be used without restriction in all common application media and applications, without showing changes in the properties of the effect pigments. In addition, the photostabilized effect pigments should be easily and inexpensively accessible, which means that the effort for their production should be low.

This complex object is achieved according to the present invention by a photostabilized effect pigment, one on a substrate or more calcined and vanadium-containing oxide layers, applied alone or in a mixture with sulfates, borates or phosphates.

The effect pigments according to the invention are notable for improved photostability, are easily accessible and can be incorporated into all conceivable application media and applications. They are chemically stable and inert and, in combination with the photostability, show the usual features of effect pigments, e.g. Gloss, color strength or variety of colors. In addition, the pigments according to the invention can be produced in a simple process with a wide selection of substrates, and, depending on the embodiment, the process for producing the pigments according to the invention can be integrated directly into the production process of the effect pigments. This means less expenditure on equipment and allows better control of the desired pigment properties, e.g. Shine, color or opacity. By using the pigments according to the invention, the addition of further photostabilizers to formulations or applications can be reduced or even dispensed with entirely, which likewise reduces the production outlay for these formulations and applications.

The effect pigments according to the invention are based on substrates, which may have any regular or irregular shape. In a preferred embodiment, the substrate consists of a platelet-shaped, spherical or needle-shaped carrier and / or a layer coated with one or more transparent, semi-transparent and / or opaque layers containing metal oxides, metal oxide hydrates, metal suboxides, metals, metal fluorides, metal nitrides, metal oxynitrides or mixtures of these materials platelet-shaped, spherical or acicular carriers. Substrates based on platelet-shaped supports are particularly preferably used. For example, platelet-shaped Ti0 ₂ , synthetic or natural mica, glass platelets, metal platelets, platelet-shaped SiO ₂ , Al ₂ 0 ₃ or platelet-shaped iron oxide. The metal platelets can consist of aluminum, titanium, bronze, steel or silver, preferably aluminum and / or titanium. The metal platelets can be passivated by appropriate treatment. In a preferred one

In one embodiment, the carrier can be coated with one or more transparent, semitransparent and / or opaque layers containing metal oxides, metal oxide hydrates, metal suboxides, metals, metal fluorides, metal nitrides, metal oxynitrides or mixtures of these materials. The metal oxide, metal oxide hydrate, metal suboxide, metal, metal fluoride,

Metal nitride, metal oxynitride layers or the mixtures thereof can be low (refractive index <1.8) or high refractive index (refractive index> 1.8). Suitable metal oxides and metal oxide hydrates are all metal oxides or metal oxide hydrates known to the person skilled in the art, such as, for. B. aluminum oxide, aluminum oxide hydrate, silicon oxide, silicon oxide hydrate, iron oxide, tin oxide, cerium oxide, zinc oxide, zirconium oxide, chromium oxide, titanium oxide, in particular titanium dioxide, titanium oxide hydrate and mixtures thereof, such as e.g. Ilmenite or pseudobrookite. For example, the titanium suboxides can be used as metal suboxides. Suitable metals are e.g. Chromium, aluminum, nickel, silver, gold, titanium, copper or alloys, as

Metal fluoride is suitable, for example, magnesium fluoride. For example, the nitrides or oxynitrides of the metals titanium, zirconium and / or tantalum can be used as metal nitrides or metal oxynitrides. Metal oxide, metal, metal fluoride and / or metal oxide hydrate layers are preferred and very particularly preferably metal oxide and / or

Metal oxide hydrate layers applied to the carrier. Furthermore, multilayer structures made of high and low refractive metal oxide, metal oxide hydrate, metal or metal fluoride layers can also be present, with high and low refractive layers alternating. Layer packages consisting of a high and a low refractive index layer are particularly preferred, it being possible for one or more of these layer packages to be applied to the support. The order of high and low-index layers can be adapted to the carrier in order to include the carrier in the multilayer structure. In a further embodiment, the metal oxide, metal oxide hydrate, metal suboxide, metal, metal fluoride, metal nitride, metal oxynitride layers can be mixed or doped with colorants or other elements. As

Colorants or other elements are suitable, for example, organic or inorganic color pigments such as colored metal oxides, e.g. Magnetite, chromium oxide or color pigments such as Berlin blue, ultramarine, bismuth vanadate, thenards blue, or organic color pigments such as Indigo, azo pigments, phthalocyanines or carmine red or

Elements such as Yttrium or antimony, photostabilized effect pigments containing these layers show, in addition to photostability, a wide range of colors in relation to their body color and can in many cases show an angle-dependent change in color (color flop) due to interference.

In a preferred embodiment, the outer layer on the carrier is a high-index metal oxide. This outer layer can additionally be part of a layer package on the above-mentioned layer packages or in the case of high-index supports and, for example, of T1O ₂ , titanium suboxides, Fe ₂ 0 ₃ , Sn0 ₂₎ ZnO, ZrO ₂ , Ce ₂ 0 ₃ , CoO, Co ₃ 0 ₄ , V ₂ O ₅ , Cr ₂ O ₃ and / or mixtures thereof, such as, for example, llmenite or pseudobrookite. TiO ₂ is particularly preferred.

In one particularly preferred in the present invention

The embodiment is titanium oxide or a substrate containing titanium oxide on the basis of a support coated with one or more transparent, semitransparent and / or opaque layers containing metal oxides, metal oxide hydrates, metal suboxides, metals, metal fluorides, metal nitrides, metal oxynitrides or mixtures of these materials. The outer layer preferably contains one or more transparent, semi-transparent and / or opaque layers containing metal oxides, metal oxide hydrates, metal suboxides, metals, metal fluorides, metal nitrides, metal oxynitrides or mixtures of these materials coated platelet-shaped, spherical or acicular carrier titanium oxide. These substrates in particular are distinguished by a high photoactivity caused by the titanium oxide, which can have a disadvantageous effect on the stability of the application medium surrounding the pigment, such as, for example, the plastic. According to the present invention, such substrates in particular can be photostabilized, which facilitates their applicability in numerous applications.

The size of the substrates is not critical per se and depends on the shape of the substrates and on the respective area of application. Substrates based on platelet-shaped carriers and / or a platelet-shaped carrier coated with one or more metal oxide, metal or metal fluoride layers generally have a thickness between 0.05 and 5 μm, in particular between 0.1 and 4.5 μm. The extension in length or width is usually between 1 and 250 μm, preferably between 2 and 200 μm and in particular between 2 and 100 μm. Substrates made of a spherical carrier and / or a spherical carrier coated with one or more metal oxide, metal or metal fluoride layers generally have average diameters of 10 nm to 100 μm, preferably between 500 nm and 50 μm and in particular between 1 and 20 μm on.

The thickness of the metal oxide, metal oxide hydrate, metal suboxide, metal, metal fluoride, metal nitride, metal oxynitride layers or a mixture thereof is usually 3 to 300 nm and in the case of the metal oxide, metal oxide hydrate, metal suboxide, metal fluoride, metal nitride , Metal oxynitride layers or a mixture thereof, preferably 20 to 200 nm. The thickness of the metal layers is preferably 4 to 50 nm. For the calcined and vanadium-containing oxide layer or oxide layers which are applied to the substrate, the oxides of Al, Ca, Sr, Zn, Si, Zr, Ce, Ti or mixtures thereof are suitable, preferably TiO ₂ , Al ₂ O. ₃ , Ce O ₃ , ZnO, ZrO and / or SiO ₂ are used. Mixtures of the above are particularly preferred

Oxides are used, ZnO being a particularly suitable mixture component of the oxide layer or oxide layers. Layers of these oxides are characterized by high transparency, lack of or little inherent color and high gloss, so that the coloristic properties of the substrates are not changed. Furthermore, these materials result in anhydrous and chemically inert surfaces after calcining. In the case of the multi-coated carrier, the oxide layer containing vanadium can be integrated into the multi-layer structure, which makes it easier to manufacture. For example, the outer layer of a multilayer pigment can contain a vanadium

Titanium oxide layer, which in addition to increasing the photostability also influences the optical properties of the pigment, e.g. through interference.

The vanadium content of the vanadium-containing oxide layer is 0.002 to 0.2% by weight, calculated as V ₂ O5 and based on the total pigment, preferably 0.01 to 0.1% by weight. The vanadium concentration in the vanadium-containing oxide layer can increase or decrease in the form of a gradient in the direction of the surface of the vanadium-containing oxide layer. The vanadium concentration in the vanadium-containing oxide layer preferably increases in the direction of the surface of the vanadium-containing oxide layer. This can further increase the photostability of the pigments, since the photoactivity of the surface of the pigment which is in contact with the application medium is reduced particularly strongly. In addition, the amount of vanadium required can be reduced in this way, which is a possible change in the color and gloss properties of the pigment prevented.

In a further embodiment, an organic coating can additionally be applied to the calcined oxide layer containing vanadium, which additionally stabilizes the pigments according to the invention against further weather influences. This enables the use of the pigments according to the invention e.g. in paints for outdoor applications that, in addition to photostability, also require high resistance to moisture. The applied organic coating can also act as a coupling reagent to the surrounding medium of the formulation or application and thus the application properties such as improve dispersibility.

The organic coating can consist of organosilanes, aluminates, titanates and / or zirconates of the general formula

X ₄ -n-mZ-Rn (-BY) _m

with X = OH, halogen, alkoxy, aryloxy Z = Si, AI, Ti, Zr

R = alkyl, phenyl or hydrogen B = organic, at least bifunctional group (alkylene, alkyleneoxyalkylene)

Y = alkyl, amino, substituted amino, hydroxy, hydroxyalkyl, siloxane, acetoxy, isocyanate, vinyl, acryloyl, epoxy, epoxypropyloxy, imidazole or ureido group n, m = 0.1, 2,3 with n + m <3 exist.

The coupling reagents consist of an anchor group (X4- _n -mZ) that binds to the surface, at least one hydrophobic group (R, B) and one or more functional groups (Y). The coupling reagents are preferably compounds with Z = Si. The anchor group preferably consists of alkoxysilanes which can be converted into corresponding hydroxyl groups by hydrolytic reaction conditions. The latter can bind to the calcined and vanadium-containing metal oxide surface and cause anchoring via oxygen bridges. In addition, mixtures of different coupling reagents can be used, which can be applied as a mixture or individually.

By choosing suitable functional groups, the organic coating can be adapted to the medium used. In addition, additional bonds between pigment and medium can be generated via the coupling reagent by reaction of the functional groups with corresponding functionalities in the application media. In a particular embodiment, the surface of the pigments according to the invention is modified with a combination of organic functionalities adapted to the feed medium. The use of mixtures of different coupling agents within the organic coating is also suitable for this. The hydrophobicity of the pigment surface can be adjusted by integrating alkyl-containing coupling reagents such as alkyl silanes. In addition to the organosilanes, the use of their hydrolysates and homogeneous and heterogeneous oligomers and / or polymers is also preferred, which can also be used as an organic coating, either alone or in combination with silanes, zirconates, aluminates, zirconium aluminates and / or carboxyzirconium aluminates. An organic coating with mixtures of different coupling reagents, in particular with functional groups Y that differ from one another, is particularly preferred, which ensures a particular range of applications. Examples of organosilanes are propyltrimethoxysilane, propyltriethoxysilane, isobutyltrimethoxysilane, n-octyltrimethoxysilane, i-octyltrimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, dodecyltrimethoxysilanilysilane As oligomeric, alcohol-free

Organosilane are, among others, those sold under the trade name "Dynasylan ^®" by the company. Sivento products, such. As Dynasylan HS 2926, Dynasylan HS 2909, Dynasylan HS2907, Dynasylan HS 2781, Dynasylan HS 2776, Dynasylan HS 2627. In In addition, oligomeric vinylsilane and aminosilane hydrolyzate are suitable as organic coatings. Functionalized organosilanes are, for example, 3-aminopropyltrimethoxysilane, 3-

Methacryloxytrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, beta- (3,4-epoxycyc! Ohexyl) -ethyltrimethoxysilane, gamma-isocyanatopropyltrimethoxysilane, 1, 3-bis (3-glycidoxypropyl) -1, 1, 3,3, -tetramethyldisil

Ureidopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-methacryloxytrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, beta- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, gamma-isocyanatopropyltrimethoxysilane are preferred. Examples of polymeric silane systems are described in WO 98/13426 and are described, for. B. from Sivento under the trademark Hydrosil ^® .

The organic coating has a positive influence on the surface properties of the calcined oxide layers containing vanadium. The surfaces coated with the organic coating are more hydrophobic and less polar than the untreated oxide surfaces and are therefore better wettable by binders and organic solvents. This results in better compatibility of the pigments according to the invention with the binder systems used in the application, in particular paints. The organic coating also inhibits because of its steric shielding of the pigment surface the agglomeration of the pigment particles and thus improves their dispersibility.

Furthermore, the object of the present invention is achieved by a method for producing photo-stabilized effect pigments, with a

One or more hydroxide, oxide hydrate and / or oxide layers containing vanadium are applied alone or in a mixture with sulfates, phosphates and / or borates and the pigment obtained is then calcined. The method according to the invention can be carried out in a one-step production process and is therefore inexpensive and simple. In the case of multilayer substrates, the method according to the invention can be directly integrated into the pigment production process.

The coating with one or more containing vanadium

Hydroxide, oxide hydrate and / or oxide layers can be carried out both wet-chemically and via sol-gel processes; the precipitation is preferably carried out wet-chemically. In the case of wet chemical application, the corresponding vanadium-containing oxides, hydroxides and / or oxide hydrates are coated. For this purpose, the substrates are suspended in a solvent or solvent mixture, preferably water, and solutions with the metal salts suitable for the formation of hydroxide, hydrated oxide and / or oxide layers and one or more vanadium compounds are added. The pH value required for the precipitation of the respective hydroxide, oxide hydrate and / or oxide is set and optimized professionally.

The vanadium compounds can be introduced at any time and in any form into the coating with the hydroxide, hydrated oxide and / or oxide layers, for example in solid form or as a solution of one or more vanadium compounds. The vanadium compounds are preferably added in the form of a solution, this being done via the Solutions of the metal salts suitable for the formation of the hydroxide, oxide hydrate and / or oxide layers and / or by means of the auxiliary solutions required in the coating process when setting the coating parameters, such as pH value or amount of solvent. The vanadium compounds are preferably added via the auxiliary solutions required for controlling the pH, the auxiliary solutions preferably being aqueous solutions of acids or bases, such as, for example, hydrochloric acid or sodium hydroxide solution. In a further embodiment, the vanadium compound can be introduced into the hydroxide, oxide hydrate and / or oxide layer such that the vanadium concentration in the layer increases or decreases in the form of a gradient in the direction of the surface of the layer containing vanadium. The gradient formation is controlled via the time and the speed of the vanadium addition. For example, if the vanadium concentration is to increase toward the surface, this can be done, for example, by adding the vanadium compounds in a targeted manner at the end of the application of the hydroxide, oxide hydrate and / or oxide layer to the substrate. The vanadium compounds can be introduced in the auxiliary solution necessary for controlling the pH, with which the precipitation of the hydroxide, oxide hydrate and / or oxide layer is completed. The desired size of the gradient can be set by controlling the speed of the addition. All other possibilities of gradient control conceivable in connection with this invention are within the knowledge of the person skilled in the art.

Suitable vanadium compounds are in principle all vanadium compounds of various oxidation levels that are soluble in a solvent or solvent mixture, for example vanadium (IV) or vanadium (V) compounds. Vanadyl (IV) salts, for example vanadyl chloride or vanadyl sulfate, vanadates or Solutions of vanadium (V) oxide, especially sodium metavanadate, are used.

The corresponding halides, nitrates and / or sulfates are suitable as metal salts for the formation of the hydroxide, oxide hydrate and / or oxide layers; the corresponding halides and / or nitrates are preferably used. The sulfates, phosphates and / or borates can be co-precipitated together with the oxides, hydroxides and / or oxide hydrates from suitable metal salts and from corresponding sulfate, phosphate or borate sources. Suitable sulfate sources are sulfuric acid and all soluble sulfates such as. As sodium sulfate, potassium sulfate or lithium sulfate, as phosphate sources phosphoric acid or all soluble phosphates such as. B. sodium phosphate, disodium hydrogen phosphate or potassium phosphate and as borate sources all soluble borates such as. B. sodium borate or sodium diborate. The amount of sulfates, phosphates and / or borates and the precipitation conditions, such as. B. pH or temperature can be optimized in a professional manner.

The pigments obtained in this way are then calcined. The calcination can take place at temperatures of 300-900 ° C, preferably at 600-900 ° C. As a result of the calcination, the precipitated oxides, hydroxides and / or oxide hydrates are dewatered, converted into the corresponding oxides and compressed.

In a further embodiment of the method according to the invention, an organic coating can additionally be applied to the calcined oxide layer containing vanadium, which additionally stabilizes the pigments according to the invention against further weather influences. The application of the organic

Coating takes place in solution at temperatures above 60 ° C, preferably above 70 ° C. Are suitable as solvents organic solvents, water or mixtures thereof, water is preferably used. The reaction time required for applying the organic coating is at least 5 minutes, preferably over a period of 10 to 90 minutes, but can also be extended as desired. The pigment obtained is worked up and isolated by methods known to those skilled in the art, e.g. B. by filtration, drying and screening.

In addition to good photostability, the photostabilized effect pigments according to the invention are notable for good application properties. The calcination dehydrates and densifies the oxide layers, which leads to a reduction in the porosity of the pigment surface. Less water can be absorbed on the compacted surface and thus the disadvantageous effects of water adsorbed in the boundary layer in the lacquer can be reduced. The calcination also removes water chemically bound in the form of hydroxides or oxide hydrates. This has advantages when using the pigments in plastics, since water present in thermoplastic polymers such as in polyesters, can lead to hydrolytic decomposition of the polymer at higher temperatures. In the case of pigments coated with hydroxides or oxide hydrates, water can be released during plastic processing, which initiates the undesired degradation of the polymer chains. With the pigments according to the invention, no water can escape due to the calcination of the oxide layer even when the pigments are processed in plastics, so that they are particularly suitable for this area of application.

Because of the improved application properties, the photostabilized effect pigments described here are suitable for one

Variety of applications. The invention thus furthermore relates to the use of the photostabilized agents according to the invention Effect pigments for pigmenting plastics, lacquers, such as hydraulic lacquers or powder lacquers, paints, printing inks, cosmetic formulations, paper, ceramic materials, glasses, foils, in security printing, in the agricultural sector, for example in seed coloring, for laser marking of, for example, paper or plastics, in Thermal protection and for the production of pigment preparations such as pearlets, pastes and pastes as well as dry preparations such as pellets, granules, chips etc, which are preferably used in printing inks and varnishes. In applications where the toxicity of the materials used plays a role, e.g. in cosmetic

Formulations, the use of vanadium (IV) compounds for producing the vanadium-containing oxide layers is preferred. The pigments according to the invention can be used in a large number of the known binders used in color systems and can be used both in aqueous and in solvent-based systems. The pigments can be incorporated into the respective application media by all methods known to the person skilled in the art.

In the case of cosmetics, the effect pigments according to the invention are particularly suitable for products and formulations of decorative cosmetics, such as, for example, nail polishes, coloring powders, lipsticks or eyeshadows, soaps, toothpastes, etc. Of course, the pigments according to the invention can also be used in the formulations with any type of cosmetic raw and auxiliary materials can be combined. These include oils, fats, waxes, film formers, preservatives and auxiliary substances that determine general application properties, such as thickeners and rheological additives such as bentonites, hectorites, silicon dioxide, calcium silicates, gelatin, high-molecular carbohydrates and / or surface-active additives, etc. Formulations containing pigments according to the invention can be of the lipophilic, hydrophilic or hydrophobic type. For heterogeneous formulations with discrete aqueous and non-aqueous phases The pigments according to the invention can each contain only one of the two phases or can be distributed over both phases.

The pH values of the aqueous formulations can be between 1 and 14, preferably between 2 and 11 and particularly preferably between 5 and 8. There are no limits to the concentrations of the pigments according to the invention in the formulation. Depending on the application, they can be between 0.001 (rinse-off products, e.g. shower gels) - 100% (e.g. gloss effect articles for special applications when using effect pigments as a substrate). The pigments according to the invention can also be combined with cosmetic active ingredients. Suitable active ingredients are e.g. Insect repellents, UV A / BC protective filters (e.g. OMC, B3, MBC), anti-aging ingredients, vitamins and their derivatives (e.g. vitamins A, C, E etc.), self-tanners (e.g. DHA, erytrolosis etc.) and others cosmetic active ingredients such as Bisaboloi, LPO, ectoin, emblica, allantoin, bioflavanoids and their derivatives.

The effect pigments according to the invention are particularly suitable for use in plastics, for example in agricultural foils, infrared-reflecting foils and disks, gift foils, plastic containers and moldings, for all applications known to the person skilled in the art, since the photostability of the effect pigments according to the invention, in particular in plastics, in order to extend the shelf life of them Leads products. All common plastics are suitable as plastics for incorporating the effect pigments according to the invention, for example duromers or thermoplastic plastics. The description of the possible uses and the plastics, processing methods and additives that can be used can be found, for example, in RD 472005 or in R. Glausch, M. Kieser, R. Maisch, G. Pfaff, J. Weitzel, Pearlescent Pigments, Curt R. Vincentz Verlag, 1996 , 83 ff., The disclosure content of which is also included here. The incorporation can take place in all known plastics and on all known to the person skilled in the art Modes take place, for example, purely physically by mixing and also chemically by reaction of appropriate functional groups of a possibly applied organic coating with the plastic. The effect pigments according to the invention are particularly suitable for applications with a high input of shear energy, as is required, for example, in some plastic applications. It was surprisingly found that the photostabilization according to the invention is still present even after very intensive mechanical loads. This is due to the very strong interactions of the stabilizing agents with the relevant interference layer.

When using the pigments in lacquers and paints, all areas of application known to the person skilled in the art are possible, such as Powder coatings, hydraulic coatings, automotive coatings, printing inks for gravure, offset, screen or flexographic printing as well as for coatings in outdoor applications. A large number of binders, in particular water-soluble types, are suitable for the production of the printing inks, e.g. based on acrylates, methacrylates, polyesters, polyurethanes, nitrocellulose, ethyl cellulose, polyamide, polyvinyl butyrate, phenolic resins, maleic resins, starch or polyvinyl alcohol. The lacquers can be water- or solvent-based lacquers, the selection of the lacquer components being subject to the general knowledge of the person skilled in the art. The pigments of the invention are preferably used in paints such as in car paints or water-based paints that are suitable for all indoor and outdoor applications due to the special stability of the pigments. In

Powder coating formulations allow the effect pigments according to the invention to be easily incorporated even without further organic coating and, in these applications, have a bright, metallic luster with a pronounced sparkle or glitter effect. When used in outdoor applications, the occurrence of chalking and graying is greatly delayed or largely avoided with highly weather-stable formulations, the so-called superdurable powder coatings. In the case of silane-based weather stabilizations known from the prior art, there are often incompatibilities with the powder coating matrix, in particular in the area of so-called dry blending, which is often expressed in strong pigment associations in the baked powder coating layer. This disorder is in the invention

Effect pigments, due to the primarily purely inorganic weather-stabilizing layer, hardly observed

Because of their wide applicability, plastics, lacquers, paints, printing inks, cosmetic formulations, paper, ceramic materials, glasses, foils, seeds, pigment preparations and dry preparations containing one or more of the photostabilized effect pigments according to the invention are also an object of the present invention.

The following examples are intended to explain the invention in greater detail without, however, limiting it.

Examples:

Determination of photoactivity:

The pigment samples were worked into a plastic matrix and the extent of the reduction from Pb ²⁺ to Pb was determined visually. The gray color is assessed according to ISO 105-Part A 02 (corresponds to DIN 54 001). The test scale ranges from 5 (very good) to 1 (very bad).

Comparative example 1:

100 g of mica flakes with a particle size of 10-50 μm are suspended in 1 liter of water and heated to 75 ° C. with stirring. An aqueous 10% solution of 3.35 g SnCl _{4 is} metered into the suspension over the course of one hour, the pH being kept at 1.8 by adding 32% sodium hydroxide solution. After a stirring time of 30 Minutes, an aqueous 30% solution of 237 g TiCl _{4 is} metered in over the course of 12 hours, the pH being kept at 1.8 by adding 32% sodium hydroxide solution. The mixture is then stirred for a further 30 minutes and the pH is adjusted to 4.0 using sodium hydroxide solution. The resulting intermediate product contains approx. 2% tin oxide and 100% titanium dioxide, based on the mica content.

The pigment is washed off from the supernatant by filtration. After drying at 120 ° C, the pigment is calcined at 800 ° C for 45 min and the effect pigment obtained is freed from coarse fractions by sieving (mesh size 63 μm) with blue interference color.

The photoactivity of this pigment is rated 1.

Example 1: The vanadium-containing pigment is produced as in

Comparative Example 1 described, the sodium hydroxide solution, which is used to keep the pH constant during the formation of the TiO ₂ layer, 64 mg of sodium vanadate * 4 H ₂ O was added. The pigment therefore contains a doping of 0.03% vanadium (V) oxide, based on the total weight.

The photoactivity of this pigment is rated 3.

Example 2: The base pigment suspension is prepared as in

Comparative Example 1 described. The pH is then adjusted to 6.5 with sodium hydroxide solution. A solution of 3.35 g of zinc chloride in 60 ml of water is added within one hour, the pH being kept constant with 5% sodium hydroxide solution in which 53 mg of sodium vanadate has been dissolved. The pigment is worked up as described in Comparative Example 1. The pigment therefore contains 2% zinc oxide and 0.025%

Vanadium oxide based on the total weight.

The photoactivity of this pigment is rated 4.

Example 3:

The pigment suspension is generally prepared as described in Comparative Example 1. Following the assignment, the pH of the suspension is adjusted to 5.0 with sodium hydroxide solution. A solution of 9.5 g of aluminum chloride * 6 H ₂ O in 100 ml of water is added over the course of an hour, the pH being kept constant with 5% sodium hydroxide solution in which 100 mg of vanadium (V) oxide has been dissolved. The pigment is worked up as described in Comparative Example 1. The pigment therefore contains 2% aluminum oxide and 0.1% vanadium oxide, based on the total weight. The body color of the pigment is yellowish. The photoactivity of this pigment is rated 3-4.

Example 4:

The pigment suspension is generally prepared as described in Comparative Example 1. During the first 75% of the occupancy, the pH is kept constant with 32% sodium hydroxide solution. 64 mg of sodium vanadate are dissolved in the sodium hydroxide solution, which is used for the remaining coating. The pigment is worked up as described in Comparative Example 1.

The pigment therefore contains a calculated 0.025% vanadium oxide based on the total weight. Due to the manufacturing conditions, the doping takes place in the form of a gradient and primarily in the outer TiO 2 layer.

The photoactivity of this pigment is rated 3-4. Example 5:

100 g of freshly produced, i.e. not yet calcined, silicon dioxide plates coated with 4.0% tin dioxide and 62% rutile are provided with a post-coating of vanadium and zirconium oxide in the mother liquor after the coating. To the tempered at 75 ° C with

Sodium hydroxide solution adjusted to pH 3.0 (volume approx. 1.5 l), with vigorous stirring, an aqueous 5% solution of 5.23 g of ZrOCl ₂ * 8 H ₂ 0 is metered in over the course of an hour, the pH being increased by adding 5% sodium hydroxide solution is kept constant. 32 mg of NH4VO4 were previously added to the sodium hydroxide solution. After stirring for 30 minutes, the pH is adjusted to 4.0 with sodium hydroxide solution and the effect pigment is separated from the supernatant by filtration and washed. After drying at 120 ° C, calcination is carried out at 800 ° C for 45 min and the pigment with green-gold interference color is freed from coarse particles by sieving (mesh size 63 μm).

The photoactivity of this pigment is rated 3-4.

Example 6: The vanadium-containing pigment is produced as in

Comparative example 1 described, wherein in the TiCU solution 54 mg

Vanadyl (IV) sulfate can be dissolved.

The pigment therefore contains a doping of 0.03% vanadium (calculated as V ₂ O ₅ ) based on the total weight. The photoactivity of this pigment is rated 3.

Claims

Expectations

1. Photo-stabilized effect pigment, characterized in that one or more calcined and vanadium-containing oxide layers, alone or in a mixture with sulfates, on a substrate,

Borates or phosphates are applied.

2. Photo-stabilized effect pigment according to claim 1, characterized in that the substrate is a platelet-shaped, spherical or needle-shaped carrier and / or with one or more transparent, semitransparent and / or opaque layers containing metal oxides, metal oxide hydrates, metal suboxides, metals, metal fluorides, metal nitrides , Metal oxynitrides or mixtures of these materials is coated platelet-shaped, spherical or needle-shaped carrier.

3. Photo-stabilized effect pigment according to claim 1 or 2, characterized in that the substrate contains titanium oxide or a substrate containing titanium oxide on the basis of one or more transparent, semitransparent and / or opaque layers containing metal oxides, metal oxide hydrates, metal suboxides, metals, metal fluorides, metal nitrides , Metal oxynitrides or mixtures of these materials is coated platelet-shaped, spherical or acicular carrier.

4. Photo-stabilized effect pigment according to claim 3, characterized in that the outer layer of the metal oxide, metal oxide hydrates, metal suboxides, metals, metal fluorides, metal nitrides, metal oxynitrides or mixtures thereof with one or more transparent, semi-transparent and / or opaque layers Materials coated platelet-shaped, spherical or acicular carrier contains titanium oxide.

5. Photo-stabilized effect pigment according to one of claims 1 to 3, characterized in that the calcined and vanadium-containing oxide layer consists of oxides of Al, Ca, Sr, Zn, Si, Zr, Ce, Ti or mixtures thereof.

6. Photostabilized effect pigment according to one of claims 1 to 5, characterized in that the vanadium content 0.002 to 0.2 wt.

%, calculated as V ₂ 0 ₅ and based on the total pigment.

7. Photo-stabilized effect pigment according to one of claims 1 to 6, characterized in that the vanadium concentration in the vanadium-containing oxide layer in the form of a gradient in

Towards the surface of the vanadium-containing oxide layer increases or decreases.

8. Photo-stabilized effect pigment according to one of claims 1 to 7, characterized in that an organic coating is additionally applied to the calcined vanadium-containing oxide layer.

9. The method for producing a photo-stabilized effect pigment according to claim 1, characterized in that on a substrate one or more vanadium-containing hydroxide, oxide hydrate and / or

Oxide layers are applied alone or in a mixture with sulfates, phosphates and / or borates and then calcined.

10. The method according to claim 9, characterized in that the substrate is a platelet-shaped, spherical or needle-shaped carrier and / or containing one or more transparent, semitransparent and / or opaque layers containing metal oxides, metal oxide hydrates, Metal suboxides, metals, metal fluorides, metal nitrides, metal oxynitrides or mixtures of these materials is coated plate-shaped, spherical or needle-shaped carrier.

11. The method according to claim 9 or 10, characterized in that the application of the hydroxide, hydrated oxide and / or oxide layers is carried out wet-chemically and / or in the sol-gel process.

12. The method according to any one of claims 9 to 11, characterized in that a vanadium compound in the hydroxide,

Oxide hydrate and / or oxide layer is introduced such that the vanadium concentration in the layer increases or decreases in the form of a gradient in the direction of the surface of the layer containing vanadium.

13. The method according to any one of claims 9 to 12, characterized in that the calcination is carried out at temperatures of 300 to 900 ° C.

14. The method according to claim 9, characterized in that an organic coating is additionally applied to the calcined vanadium-containing oxide layer.

15. Use of photo-stabilized effect pigments according to claim 1 in plastics, lacquers, paints, printing inks, cosmetic

Formulations, paper, ceramic materials, glasses, foils, in security printing, for laser marking, for heat protection or for seed coloring as well as in dry preparations and pigment preparations.

16. Plastics, varnishes, paints, printing inks, cosmetic

Formulations, paper, ceramic materials, glasses, foils, Seeds, pigment preparations as well as dry preparations containing one or more photostabilized effect pigments according to claim 1.