EP1517951A2

EP1517951A2 - Uv-stabilised particles

Info

Publication number: EP1517951A2
Application number: EP03788888A
Authority: EP
Inventors: Adalbert Huber
Original assignee: Merck Patent GmbH
Current assignee: Merck Patent GmbH
Priority date: 2002-06-24
Filing date: 2003-06-23
Publication date: 2005-03-30
Also published as: JP2005532467A; WO2004029144A2; AU2003293294A8; US20060155007A1; AU2003293294A1; DE10228186A1; CN100475895C; CN1662594A; WO2004029144A3; US7579079B2

Abstract

The invention relates to UV-stabilised particles, which are characterised in that they reflect or absorb light in the 290 to 500 nm wavelength range. The invention also relates to a method for producing the inventive particles and to their use in varnishes, water varnishes, powder varnishes, dyes, printing inks, security printing inks, plastics, concrete, cosmetic formulations, agricultural films and tarpaulins, for the laser marking of paper and plastics, as sun filters and also for producing pigment preparations and dry preparations.

Description

UV stabilized particles

The present invention relates to UV-stabilized particles which are distinguished in that they reflect or absorb light of the wavelengths from 290 to 500 nm.

Paints are usually provided with a UV filter, which is added to the paint as a powder or liquid. In the case of plastics or powder coatings, protection is provided by adding these filters to the batch to be extruded. It is often recommended to use varnishes or

Powder coatings also contain a tertiary amine, e.g. 2,2,6,6 tetramethylpiperidine. The UV protection of paints, powder coatings or plastics is often necessary because the pigments or particles they contain have inadequate UV stability. For example, graying occurs when BiOCI pigments are irradiated with light, in particular UV light. Therefore, BiOCI pigments are usually offered in a solution or as a preparation with a UV absorber. However, such solutions or preparations have the disadvantage that the UV absorber, based on the pigment, has to be used in relatively large concentrations, which leads to various disturbances in the application media.

The object of the present invention is therefore to provide UV-stabilized particles which can be easily and without problems incorporated into the application media and at the same time can be produced in a simple manner.

Surprisingly, it has now been found that the light resistance of particles, such as BiOCI, can be greatly increased if the surface of these particles is coated directly with a UV stabilizer. The UV absorber should reflect or absorb the light of wavelengths from 250 to 500 nm. By applying and immobilizing UV stabilizers on the particle surface, a significantly higher efficiency of UV protection is achieved compared to a mixture consisting of particles and UV stabilizer. The direct UV protection agent / particle surface contact also leads to a clear lower concentration of the UV protection agent compared to direct use in paints, powder coatings and plastics. Furthermore, the diffusion of the UV protective agent in the application medium is prevented, which is the cause of various faults in paints, powder coatings and plastics. Compared to the prior art, the UV-resistant particles can be used in pure powder form in the application media and not as a solution or as a preparation.

The invention thus relates to UV-stabilized particles which are distinguished by the fact that they reflect or absorb light of the wavelengths from 290 to 500 nm.

The invention further relates to the production of the particles according to the invention and their use, inter alia. in paints, water-based paints, powder paints, paints, printing inks, security printing inks, plastics and in cosmetic formulations. Furthermore, the particles according to the invention are also suitable for the production of pigment preparations and for the production of dry preparations.

All organic or inorganic particles known to the person skilled in the art that are sensitive to UV light can be stabilized by the process according to the invention. The particles can be spherical, acicular or platy. The size of the particles is not critical per se and can be tailored to the particular application. As a rule, the spherical particles have a diameter of 0.02-100 μm, particularly 0.03-20 μm and in particular 0.05-1 μm. The needle-shaped particles are 0.05-10 μm long, preferably they have lengths of 0.05-5 μm, in particular 0.05-1 μm. The particularly preferred substrates are platelet-shaped substrates. Suitable platelet-shaped substrates have a thickness between 0.02 and 5 μm, in particular between 0.1 and 4.5 μm. The expansion in the other two areas is usually between 1 and 500 μm, preferably between 2 and 200 μm, and in particular between 5 and 60 μm. Inorganic and organic pigments and mixtures thereof are suitable as particles.

Suitable inorganic particles are, for example, uncoated or with one or more metal oxides coated SiO ₂ spheres, fillers,

Fluorescent pigments, white pigments, such as e.g. Titanium dioxide, zinc white, colored zinc oxide, lead white, zinc sulfide, lithopone, black pigments such as Iron-manganese black, spinel black, iron oxide black, colored pigments, e.g. Chromium oxide, chromium oxide hydrate green, chrome green, cobalt green, ultramarine green, cobalt blue, ultramarine blue, iron blue,

Manganese blue, ultramarine violet, cobalt and manganese violet, iron oxide red, cadmium sulfoselenide, molybdate red, ultramarine red, iron oxide brown, mixed brown, spinel and corundum phases, chrome orange, iron oxide yellow, nickel titanium yellow, chromium titanium yellow, cadmium zinc sulfate, yellow gelatin yellow gelate, yellow gelatin yellow zincate, chrome yellow gelatin yellow zincate CrO ₂ , Fe ₂ O ₃ , Fe ₃ O, co-modified iron oxides, Ba ferrites and pure iron pigments, graphite platelets, effect pigments, holographic pigments and BiOCI.

. As effect pigments are preferably commercially available metallic effect pigments such as ChromaFIair pigments by the firm Flex, coated or uncoated aluminum platelets, gold bronze pigments, for example by the firm Eckart, coated iron oxide platelets, such as Paliochrom ^® -. Pigments from BASF, Sicopearl pigments of the BASF and goniochromatic pigments from BASF, as described in EP 0753545 A2, for example, as well as pearlescent pigments and interference pigments - metal oxide-coated mica flake pigments - used available for example from Merck, Darmstadt under the trade name Iriodin ^®.. The latter are known, for example, from German patents and patent applications 14 67 468, 19 59 998, 20 09 566, 22 14 545, 22 15 191, 22 44 298, 23 13 331, 25 22 572, 31 37 808, 31 37 809, 31 51 343, 31 51 354, 31 51 355, 32 11 602, 32 35 017, DE 3842 330, DE 41 37 764, EP 0 608 388, DE 196 14 637, DE 196 18 569. Pearlescent pigments are preferably used. In particular, mica pigments coated with Ti0 ₂ and / or Fe ₂ 0 ₃ , SiO ₂ - Platelets, Al ₂ 0 ₃ platelets, glass platelets, ceramic platelets or synthetic carrier-free platelets are used.

Particularly preferred inorganic pigments are BiOCI platelets, Ti0 ₂ particles, fluorescent pigments, holographic pigments, conductive and magnetic pigments, metal effect pigments, for example based on aluminum platelets, and effect pigments, such as, for example, pearlescent pigments, interference pigments, goniochromatic pigments, such as base layer, multi-layer pigments natural or synthetic mica, Al ₂ O ₃ , Ti0 ₂ , Si0 ₂ , Fe ₂ 0 ₃ , glass or graphite flakes. Preferred effect pigments are coated with Ti0 ₂ (rutile or anatase) substrates, such as. B. with TiO ₂ coated natural or synthetic mica, coated with Ti0 ₂ Si0 ₂ -, Al ₂ 0 ₃ -, graphite, glass, Fe ₂ 0 ₃ - or metal platelets, especially aluminum platelets. Also preferred are multi-layer pigments with two, three or more layers which contain one or more TiO ₂ layers and spherical SiO ₂ particles which can be coated with one or more metal oxides.

Suitable organic pigments from the color index list are e.g. Monoazo pigments C.I. Pigments Brown 25, C.I. Pigment Orange 5, 13, 36, 67, C.I. Pigment Red 1, 2, 3, 5, 8, 9, 12, 17, 22, 23, 31, 48: 1, 48: 2, 48: 3, 48: 4, 49, 49: 1, 52: 1, 52: 2, 53, 53: 1, 53: 3, 57: 1, 251, 112, 146, 170, 184, 210, and 245, Cl Pigment Yellow 1, 3, 73, 65, 97, 151 and 183; Diazo pigments C.I. Pigment Orange 16, 34 and 44, C.I. Pigment Red 144, 166, 214 and 242, C.I. Pigment Yellow 12, 13, 14, 16, 17, 81, 106, 113,

126, 127, 155, 174, 176 and 188; Anthanthrone Pigments C.I. Pigments Red 168, anthraquinone pigments C.I. Pigment Yellow 147 and 177, C.I. Pigment violet 31; Anthrapyrimidine pigment duck C.I. Pigment Red 122, 202 and 206, C.I. Pigment violet 19; Quinophthalone Pigments C.I. Pigment yellow 138; Dioxazine pigments C.I. Pigment yellow 138; Dioxazine pigments C.I.

Pigments Violet 23 and 37; Flavanthrone pigments Cl Pigment Blue 60 and 64; Isoindoline pigments Cl Pigment Orange 69, Cl Pigment Red 260, Cl Pigment Yellow 139 and 185; Isoindolinone pigments Cl Pigment Orange 61, Cl Pigment Red 257 and 260, Cl Pigment Yellow 109, 110, 173 and 185; Isoviolanthrone pigments Cl Pigment Violet 31, metal complex pigments Cl Pigment Yellow 117 and 153, Cl Pigment Green 8; Perinone pigments Cl Pigment Orange 43, Cl Pigment Red 194; Perylene pigments Cl Pigment Black 31 and 32, Cl Pigment Red 123, 149, 178 17j9, 190 and 224, Cl Pigment Violet 29; Phthalocyanine pigments Cl Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6 and 16, Cl Pigment Green 7 and 36; Pyranthrone pigments Cl Pigment Orange

51, C.I. Pigment red 216; Thioindigo Pigments C.I. Pigment Red 88 and 181, C.I. Pigment violet 38; Triaryl carbonium pigments C.I. Pigment Blue 1, 61 and 62, C.I. Pigment Green 1, C.I. Pigment Red 81, 81: 1 and 169, C.I. Pigment violet 1, 2, 3 and 27; Aniline black (C.I. Pigment Black 1); Aldazine Yellow (C.I. Pigment Yellow 101) and C.I. Pigment Brown 22 and Liquid Crystal Polymers (LCP pigments).

Particularly preferred organic pigments are azo pigments, liquid crystal polymers and fluorescent pigments.

Mixtures of different particles / pigments can also be stabilized by the process according to the invention.

The UV resistance of the above-mentioned particles is significantly increased by applying UV protection agents or UV stabilizers to the particle surface. The UV protective agents / stabilizers are preferably fixed on the particle surface in that the protective agent is applied to the surface in combination with a polymer or polymer mixture.

The proportion of UV protection agent / stabilizer on the particle surface depends on the particle to be protected. The particles preferably contain 0.001 to 1000% by weight, particularly preferably 0.01 to 500% by weight and in particular 0.1 to 100% by weight, based on the particles.

For example, the BiOCI platelets according to the invention contain 5 to 70% by weight, in particular 10 to 50% by weight, of UV stabilizer on the surface. , Suitable UV stabilizers are known to the person skilled in the art and are commercially available, such as, for example, UV absorbers, UV reflectors, UV scattering agents, antioxidants, dyes, soot particles, free radical scavengers and microtitanium.

Suitable UV absorbers are, for example, benzotriazoles, triazines,

Oxanilides, benzophenones, arylated cyanoacrylates, especially hydroxy-benzotriazoles such as 2- (3 ', 5'-bis (1, 1-dimethylbenzyl) -2'-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-5 '- (tert-octyl) phenyl) benzotriazole, 2- (2 ^, -hydroxy-3' - (2-butyl) -5 '- (tert-butyl) phenyl) benzotriazole, bis (3rd -2H-benzotriazolyl) -2-hydroxy-5-tert-octyl) methane, 2- (4-hexoxy-2-hydroxyphenyl) -4,6-diphenyl-1, 3,5-triazine, and the benzophenone 2,4-dihydroxybenzophenone.

Suitable UV absorbers are also carbon black and UV scattering agents, such as cyanaralic acid derivatives.

Radical scavengers can also be used as UV protection agents. Suitable radical scavengers are e.g. organic and inorganic nitro compounds, phenols, such as. B. hydroquinones, condensed aromatic compounds, hindered amines (HALS).

In the case of UV-reflecting protective agents, metals, nanoparticles, e.g. from titanium dioxide or iron oxide, titanium dioxide, barium sulfate. Nanoparticles are understood here to mean organic, inorganic, metallic particles with a size of <300 nm, preferably <150 nm.

Mixtures of different UV protection agents can also be used, the mixing ratio being unlimited. Mixtures consisting of radical scavengers and soot particles are particularly preferred.

Particularly preferred UV stabilizers are 2-hydroxybenzophenones, 2-hydroxyphenylbenztriazoles, 2-hydroxyphenyltriazines, oxalanilides, triazoles, triazines, titanium dioxide nanoparticles, iron oxide nanoparticles, carbon black, Hiπdered amines (HALS) and mixtures of the UV stabilizers mentioned.

A UV protective agent can also be copolymerized in order to prevent absorption through the skin, which is particularly desirable in the case of cosmetic products.

The particles according to the invention are easy to produce. The UV protective agent is fixed on the particle surface to be protected by an upstream or by a simultaneous precipitation of a suitable polymer or, if the protective agent itself is a polymer, by the sole precipitation thereof.

A particularly preferred method is the fixing of the UV protection agents on the particle surface with LCST and / or UCST polymers.

LCST polymers or UCST polymers are polymers which are soluble in a solvent at low or higher temperatures and when the temperature is increased or decreased and the so-called LCST or UCST (Iower or upper critical solution temperature) is reached be separated from the solution as a separate phase. Such polymers are e.g. in the literature in "Polymers", H.-G. Elias, Hüthig and Wepf-Verlag, Zug, 1996 on pages 183 ff.

Suitable LCST polymers for the present invention are, for example, those as described in WO 01/60926 A1.

Particularly suitable LCST polymers are polyethylene oxide (PEO) derivatives, polyethylene oxide (PPO) derivatives, in particular acrylate-modified PEO-PPO-PEO three-block copolymers, polymethyl vinyl ether, poly-N-vinylcaprolactam, ethylhydroxyethyl cellulose, poly-N-isopropyl acrylamide and olefinic siloxane polymers.

Suitable UCST polymers are in particular polystyrene, polystyrene copolymers and polyethylene oxide copolymers. The polymer content based on the end product is 0.1-80% by weight, preferably 1-30% by weight, in particular 1-20% by weight.

The UV protection agents or their mixtures are either applied directly to the surface to be protected and coated with LCST and / or UCST

Immobilized polymers or applied and immobilized in one step as a mixture with LCST and / or UCST polymers on the surface.

The UV protection agent is preferably immobilized

Polymers or polymer mixture, preferably an LCST and / or UCST polymer, optionally mixed in the presence of a solvent. The LCST polymer / protective agent mixture is dissolved at the temperature below the LCST, while the UCST polymer / protective agent solution is dissolved above the UCST. As a rule, the LCST temperature is 0.5-90 ° C., preferably 35-80 ° C., while the UCST temperature is 5-90 ° C., in particular 35-60 ° C. Then the particles to be stabilized are added. The temperature is then increased, usually by about 5 ° C. above the LCST or below the UCST, the polymer with the UV protection agent precipitating and settling on the particle surface. Finally, the immobilization takes place in the form of a crosslinking of the polymer on the particle surface, the polymer being irreversibly fixed on the particle surface. The immobilization can take place radically, cationically, anionically or through a condensation reaction. The LCST or UCST polymers are preferably crosslinked by free radicals or by a condensation reaction.

For a radical crosslinking (immobilization) of the deposited layer in water, potassium peroxodisulfate or is preferably used

Ammoπiumperoxodisulfat in concentration ranges of 1 - 100 wt.% Based on the olefinic LCST or UCST polymer used for the coating. The crosslinking takes place depending on the LCST or UCST temperature of the polymer at 0 - 35 ° C using a catalyst, such as. B. a Fe (ll) salt, or at 40 - 100 ° C by direct thermal decomposition of the radical initiator. The particles are preferably mixed into the solution of the LCST or UCST polymer as a dispersion, the same solvent as that of the polymer solution preferably being used and the temperature of the dispersion being lowered below the LCST or UCST. However, the particles can also be directly dispersed in the LCST or UCST solution.

If a solvent is required in the process according to the invention, the choice of solvent depends on the solubility of the polymer used. The solvent is preferably water or a water-miscible organic solvent. The water-miscible solvents also include those solvents which have gaps in the mixture with water. In these cases, the proportions are chosen so that there is miscibility. Examples of suitable solvents are mono- and polyalcohols, e.g. Methanol, ethanol, n-propanol, isopropanol, glycol, glycerin, propylene glycol, polyethylene glycol, polybutylene glycol and the mono- and diether with methanol, ethanol, propanol and butanol of the polyalkylene glycols; Ethers such as Tetrahydrofuran, dioxane, 1,2-propanediol propyl ether, 1,2-butane 1-methyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether; Esters, e.g. Methyl acetate, monoesters of ethylene glycol or propylene glycols with acetic acid, butyrolactone; Ketones such as acetone or methyl ethyl ketone; Amides such as formamide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and hexamethylphosphoric acid triamide; Sulfoxides and sulfones such as e.g. Dimethyl sulfoxide and sulfolane, alkane carboxylic acid such as formic acid or acetic acid,

Suitable solvents are in particular water, furthermore organic solvents, such as e.g. Alcohols and glycols.

The LCST and / or UCST polymer coatings are particularly preferably carried out as a complete coating of the particles.

The aftertreatment according to the invention further increases the chemical stability of the particles and at the same time the handling of the particles, in particular the incorporation into different application media, relieved. The particles according to the invention have increased stability against flocculation in water-based paints or against the formation of structures in the case of organic paint systems.

The UV-stabilized particles also show very good weather resistance, very good dispersing behavior and, because of their stability, are very well suited for a wide variety of application systems, in particular for aqueous and organic paints.

The UV-stabilized particles are compatible with a large number of color systems, preferably in the field of paints, water-based paints, powder coatings, paints, printing inks, security printing inks, plastics and cosmetic formulations. Furthermore, the particles according to the invention are also for the laser marking of papers and plastics, as light protection, for coloring concrete and for

Agricultural applications, e.g. for greenhouse films, e.g. suitable for the coloring of tarpaulins.

It goes without saying that the particles according to the invention are also advantageously mixed with organic dyes, organic pigments or other pigments, such as, for example, transparent and opaque white, colored and black pigments, and with platelet-shaped iron oxides, organic pigments, for the various purposes of use. holographic pigments, LCPs (liquid crystal polymers), and conventional transparent, colored and black gloss pigments based on metal oxide coated mica, glass, Al ₂ 0 ₃ , graphite and Si0 ₂ platelets, etc. can be used. The particles stabilized according to the invention can be mixed in any ratio with commercially available pigments and fillers.

The particles according to the invention are also suitable for the production of flowable pigment preparations and dry preparations, such as, for example, granules, briquettes, sausages, pellets, etc. The pigment preparation and dry preparations are distinguished by the fact that they contain at least one or more particles, binders and, optionally, one or more Contain additives. The invention also relates to the use of the UV-stabilized particles in paints, water-based paints, powder paints, paints, printing inks, security printing inks, plastics, concrete, also in cosmetic formulations, for laser marking of papers and plastics, as pigments in corrosion protection, in agricultural films and tarpaulins as well as for the production of pigment preparations and dry preparations.

The invention thus also relates to formulations which contain the pigment preparation according to the invention.

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

Examples

example 1

Example 1a: UV stabilization of BiQCI pigments 0.25 g of benzotriazole dehvate (UV absorber from Ciba-Geigy) are mixed with 1.0 g of modified LCST polymer (three-block copolymer based on polypropylene oxide, polyethylene oxide) and mixed in 20 ml of distilled water dissolved at 23 ° C. Then (up to 30 microns in the _dispersion. Product from platy BiOCl pigment of particle size 10th Merck KGaA, Germany) 20 g of bi-flair ^® 83S paste stirred in a dissolver at 200 rev / min. After stirring for 5 minutes at 23 ° C., the mixture is heated to 40 ° C. After stirring for a further 10 minutes at 40 ° C., 1.0 g of potassium peroxodisulfate are added and heated to 65 ° C. and crosslinked within 2 hours. It is cooled to room temperature, 20 ml of water are added and the pigments are separated from the liquid by centrifugation. The UV-stabilized pigments are washed with water and centrifuged off. So much water is now added to the pigment cake thus obtained until the solids concentration in the pigment paste is approximately 50%. Example 1 b: Production of a pigmented water-based paint A water-based paint pigmented with the UV-stabilized BiOCI pigments from Example 1a and with untreated BiOCI pigments is prepared by adding 5 g of pigment paste (corresponds to 2.5 g of pigment) in 15 g of a water-based paint acrylic / melamine based. The water-based paint is put together

147.2 g Viacryl SC 323 W / 70SBB, from Vianova

49.1 g Maprenal MF 501w / 63EDGM, from Clariant

14.3 g triethylamine

489.4 g dist. water

Example 1c: Color measurements

Glass slides are used as substrates for the differently pigmented paint samples. The dry layer thickness of the opaque lacquer layers that are applied to the glass slides is 100 μm after a 0.5-hour baking process in a convection oven at 125 ° C.

The UV exposure is carried out in the Xenotest for 24 or 45 hours. The damage to the pigment is determined colorimetrically by measuring the change in the brightness value L *. The color measurements are carried out using the 45 ° measuring geometry and a Datacolor device. The results of the color measurements are summarized in Table 1.

Table 1: Decrease of the L value in% of the paint samples after 24 and 45 h UV exposure:

The investigation of the UV resistance of BiOCI pigments in water-based paints clearly shows that a coating with UV protection agents using LCST polymers significantly improves the UV resistance.

Example 2

Example 2a: UV stabilization of BiOCI pigments with carbon black 0.1 g of carbon black (Spezialschwarz 350, from Degussa-Hüls AG) are mixed with 2.0 g of modified LCST polymer (polypropylene oxide diacrylate). The mixture is then dispersed on the Scandex for 0.5 h and 40 ml of dist. Water added. The pigment preparation obtained is briefly shaken, 20 ml are removed and the mixture is cooled to 0.5 ° C. and stirred in a dissolver until a homogeneous mixture has formed. Then 20 g of Bi-Flair ^® 83S paste are stirred into the mixture. After stirring for 15 minutes at 0.5 ° C, the mixture is warmed to 23 ° C. After stirring for a further hour, 1 g of an acrylate-modified PEO-PPO-PEO polymer dissolved in 20 ml of distilled water is added and the mixture is heated to 50.degree. Then 0.3 g of potassium peroxydisulfate in 10 ml of water is added. It is heated to 65 ° C. and crosslinked at this temperature for 2 hours. After cooling to room temperature, 20 ml of water are added and the pigments are separated from the liquid by centrifugation. The stabilized pigments are washed with water and centrifuged off. So much water is now added to the pigment cake obtained by centrifugation until the solids concentration is approximately 50%.

Example 2b: Preparation of a pigmented water-based paint Analogous to Example 1b, pigmented water-based paints are produced by stirring 5 g of pigment paste (corresponds to 2.5 g of pigment) into 15 g of an acrylic / melamine-based water-based paint. Example 2c: Color measurements

The color change of the BiOCI pigments stabilized with carbon black is compared with unmodified pigments in the respective lacquer layer. The results of the color measurements are summarized in Table 2.

Table 2: Decrease of the L * value in% of the paint samples after 12 h UV exposure:

The BiOCl pigments stabilized with carbon black show a significantly higher UV resistance compared to the non-stabilized BiOCI pigments.

Claims

claims

1. UV-stabilized particles, characterized in that they reflect or absorb light of the wavelengths from 290 to 500 nm.

2. UV-stabilized particles according to claim 1, characterized in that the particles are coated on the surface with an immobilizable polymer or polymer mixture, the polymer layer containing or enclosing one or more UV protection agents or UV stabilizers.

3. UV-stabilized particles according to claim 1 or 2, characterized in that the UV protective agent or the UV stabilizer is selected from the group of UV absorbers, UV reflectors, UV scattering agents, antioxidants, dyes, soot particles , Radical scavengers, microtitanium or mixtures thereof.

4. UV-stabilized particles according to claim 3, characterized in that the UV protective agent or the UV stabilizer is selected from the group of benzophenones, triazoles, triazines, titanium dioxide.

Nanoparticles, iron oxide nanoparticles, carbon black, hindered amines (HALS) and mixtures thereof.

5. UV-stabilized particles according to one of claims 1 to 4, characterized in that the particles contain 0.001 to 1000% by weight of UV protection agent or UV stabilizer, based on the particles.

6. UV-stabilized particles according to claim 2, characterized in that the polymer is applied to the particle surface by precipitation in water and / or an organic solvent.

7. UV-stabilized particles according to one of claims 1 to 6, characterized in that the particles are platelet-shaped, spherical or needle-shaped.

8. UV-stabilized particles according to one of claims 1 to 7, characterized in that the particles are selected from the group of BiOCI platelets, Ti0 ₂ particles, fluorescent pigments, holographic pigments, pearlescent pigments, interference pigments, multilayer pigments, metallic effect pigments, goniochromatic

Pigments, conductive and magnetic pigments, organic pigments, azo pigments.

9. UV-stabilized particles according to claim 8, characterized in that the pearlescent pigments, interference pigments, multilayer pigments and goniochromatic pigments on natural or synthetic mica, Al ₂ 0 ₃ -, Ti0 ₂ -, Si0 ₂ -, Fe ₂ 0 ₃ -, Glass or graphite flakes are based.

10. Process for the preparation of UV-stabilized particles

Claim 1, characterized in that one or more UV protection agents or UV stabilizers are either applied directly to the particle surface to be protected and immobilized with a subsequently applied polymer or polymer mixture or in one step as a mixture with the polymer or the polymer onto the surface and irreversibly immobilized.

11. The method according to claim 10, characterized in that the polymer is an LCST and / or UCST polymer or polymer mixture of LCST and / or UCST polymers.

12. Use of the UV-stabilized pigments according to claim 1 in paints, water-based paints, powder coatings, paints, printing inks, security printing inks, plastics, concrete, in cosmetic formulations, in agricultural films and tarpaulins, for laser marking of papers and plastics, as light protection, and for the production of pigment preparations and dry preparations.

13. Formulations containing the UV-stabilized pigments according to claim 1.