DE102008005826A1 - Particle, useful in e.g. cosmetics, lacquers and plastics, comprises core and shell comprising oligomer and/or polymer with nitrogenous functional group - Google Patents

Abstract

Particle comprises a core and a shell comprising an oligomer and/or polymer with at least one nitrogenous functional group, where the particle exhibits a reflection and/or absorption at a wave length of 750-2500 nm. Independent claims are included for: (1) a molded mass comprising the core and the oligomer and/or polymer with at least one nitrogenous functional group, where the molded mass shows reflection and/or absorption at a wave length of 750-2500 nm; and (2) the preparation of the particle comprising mixing the oligomer and/or polymer with the core optionally in a solvent or its mixture, and subsequently drying the mixture.

Description

The The present invention relates to particles comprising a core and a shell comprising oligomers and / or polymers, process for their production and their use.

Nanoparticles are increasingly being used, for example in paint applications. These materials are particularly suitable for functional applications in which the absorption of electromagnetic radiation, in particular in the non-visible range z. B. UV / IR radiation area, must be coupled with the highest possible transparency in the visual field. Materials which are often used for this purpose are based on nanoparticulate zinc oxides, titanium dioxides or tin oxides. However, for the properties which these nanomaterials are intended to develop in the application, the state of dispersion of the nanoparticles in the application medium is of particular importance. The production of nanoparticles by milling processes ( WO 2006/018169 ) or by sol / gel method is state of the art, but the stabilization of these particles in the different application systems is still a difficult task, since the particles tend to agglomerate. For this reason, the nanoparticles are usually introduced in the form of a suspension, for example in water, in the appropriate application medium. However, this procedure has the disadvantage that a not inconsiderable amount of solvent is introduced into the application system. Since the respective application systems often incompatible with the solvent, eg. As water are, or change their properties by adding the suspensions, it is still difficult to incorporate nanoparticles in a variety of applications.

Desirable and of practical interest is therefore the generation of a nanoparticulate Dispersion without application of high shear forces from solid powdery substances.

These Complex problem is solved by the present invention. For this reason, a first object of the present invention providing particles comprising a core and a shell Oligomers and / or polymers with at least one nitrogen-containing functional group, where the particles are at wavelengths show between 750 and 2500 nm reflection and / or absorption. Preferably lie the particles of the invention as a powder. The wavelengths are within the scope of the present invention Invention on wavelengths of the electromagnetic spectrum.

in the Within the scope of the present invention, a powder spectrum is created (Perkin-Elmer Lambda 900 spectrophotometer, measurement in quartz glass cuvettes, Layer thickness of the powder: 1 mm), the powdery Samples irradiated on a quartz plate diffusely from 200 to 2500 nm become. Reflection and transmission values are measured and the absorption values derived therefrom.

at the core of the particles of the invention is It is basically any kind of particle, no matter which one Shape. Preferably, the cores are nanoparticles.

suitable Particles are selected from the group comprising hydrophilic and hydrophobic, in particular hydrophilic particles, in particular nanoparticles, based on oxides, hydroxides, sulfides, sulfates, carbonates and / or nanoparticles which silicon, titanium, zinc, tin, aluminum, Indium, copper, antimony, cerium, cobalt, chromium, nickel, iron, yttrium and / or zirconium, or metals, such as Ag, Cu, Fe, Au, Pd, Pt or alloys included. The particles based on Oxides, hydroxides, sulfides, sulfates, carbonates and / or particles, consisting of titanium, zinc, tin, aluminum, cerium, cobalt, chromium, Nickel, iron, yttrium, zirconium, metals, alloys and / or Mixtures of these can optionally with oxides or hydroxides be coated by silicon. The individual oxides can also present as mixtures. Furthermore, the cores can be doped with elements based on oxides, preferably with other metal ions such as indium or antimony or halogens, in particular with fluorine.

Preferably the particles have an average particle size, determined by means of a Malvern ZETASIZER (dynamic light scattering) or transmission electron microscope, from 3 to 200 nm, in particular of 20 to 80 nm and most preferably from 30 to 50 nm. In specific likewise preferred embodiments of the present invention is the distribution of particle sizes tight, d. H. the fluctuation range is less than 100% the mean, in particular preferably not more than 50% of the mean value (according to particle distribution function, determined by dynamic light scattering). Particular preference is given to nanoparticles based on silicon dioxide, used.

Very particular preference is given to nanoparticles based on metals, wherein the cores in particular have more than 50% by weight of gold, silver, copper or iron. Very particularly preferred are Ker ne based on tin oxide, which is most preferably doped with fluorine or antimony. The proportion of the dopant, in particular fluorine, is in the range of 0.5 to 15 wt .-%, based on the core. Particulate particles having these materials as the core have the advantage that the powder produced from them has a greater ratio between the absorption or reflection in the infrared range (eg at 2500 nm) and the absorption or reflection in the visual wavelength range (eg. B. 600 nm) show. If analogous doped tin oxides are used according to the prior art and a corresponding powder spectrum is measured, then the ratio of the absorption regions or reflection regions is substantially lower. The mentioned cores are enveloped by a shell comprising oligomers and / or polymers having at least one nitrogen-containing functional group. In particular, the oligomers and / or polymers are thermoplastic oligomers and / or polymers.

thermoplastic Oligomers and / or polymers have the advantage that they are used in the Dissection can not be networked, therefore, going easier let produce. For powder coatings and plastics applications provide these coatings, unless the compatibility with the application components is guaranteed, more Advantages because they do not contain infusible components which as paint defects could be noticeable.

Most preferably, the oligomers and / or polymers are LCST or UCST oligomers and / or polymers. LCST polymers or UCST polymers are polymers which are soluble at low or high temperatures in a solvent and when the temperature is raised or lowered and the so-called LCST or UCST is reached (lower or upper critical solution temperature) the solution are deposited as a separate phase. Such polymers are described, for example, in the literature in "Polymers", H.-G. Elias, Hüthig and Wepf-Verlag, Zug, 1996 on pages 183 ff. described.

Suitable LCST polymers or UCST polymers for the present invention are, for example, those as described in the WO 01/60926 A1 and WO 03/014229 A1 to be discribed.

Especially suitable LCST polymers are polyalkylene oxide derivatives, preferably Polyethylene oxide (PEO) derivatives, polypropylene oxide (PPO) derivatives, olefinically modified PPO-PEO block copolymers modified with acrylate PEO-PPO-PEO triblock copolymers, polymethyl vinyl ether, poly-N-vinyl caprolactam, ethyl (hydroxyethyl) cellulose, Poly (N-isopropylacrylamide) and polysiloxanes. Particularly preferred LCST polymers are siloxane polymers modified with olefinic groups.

suitable In particular, UCST polymers are polystyrene, polystyrene copolymers and polyethylene oxide copolymers.

Prefers LCST or UCST polymers with functional groups are used, the strong interactions and / or chemical bonds with the Effect pigment and the application medium, such. B. the paint matrix, received. All functional groups known to those skilled in the art are especially silanol, amino, hydroxyl, epoxy, acid anhydride and acid groups.

The LCST or UCST polymers preferably have molecular weights in the range from 300 to 500,000 g / mol, in particular from 500 to 20,000 g / mol.

at The nitrogen-containing functional group may in principle to all functional groups with nitrogen atoms known to those skilled in the art act, for example, amino groups, amide groups or amino groups with an aromatic character. Preferably, the oligomers contain and / or polymers at least one amino function. The amino-functional Polymers are reactive compounds that are found in many Application systems, for example, paints, can crosslink, so that surface effects and especially softening effects are almost impossible. Since the use concentrations of Nanoparticles usually in the low percentage range or below and the amount of polymers used are also common below 1%, an effect on the curing behavior of the Application systems are normally excluded.

In a particularly preferred manner, the oligomers and / or polymers are amino-functional polyethers. Particles of the invention based on nanoparticles as the core and aminofunctional polyethers as the shell prove to be particularly suitable since they are particularly easy to mix into a wide variety of application systems. In this way, "stirr-in nanoparticles" can be provided as powders or granules Suitable amino-functional polyethers are the preferably used Jeffamines from Huntsmann, in particular polymers with ethylene oxide and / or Propylenoxidanteilen, wherein the end groups are preferably amino-functional. These polymers usually have LCST temperatures in the range of 40 ° C, which (, Germany z. B. means Turbiquant ^® from. Merck KGaA) are easy to Turbidimetermessungen in the respective concentration range determined. For this purpose, the LCST polymer is dissolved in water, heated and measured the permeability of a light beam. In the range of the LCST temperature, the light transmission decreases dramatically.

Of the Polymer content, based on the invention Particle is 0.5-10 wt .-%, preferably 1-8 wt .-%, in particular 1-5 wt .-%.

About that In addition, the above-mentioned cores and oligomers and / or Polymers having at least one nitrogen-containing functional group, also in the form of molding compositions. Comprising these molding compositions Cores and oligomers and / or polymers containing at least one nitrogen-containing functional groups may also be at wavelengths show between 750 and 2500 nm reflection and / or absorption.

The Particles according to the invention show at wavelengths between 750 and 2500 nm, measured in powder form, with respect to the visual wavelength range pronounced reflection (Kern consists of nanoparticulate metals, especially nanoparticulate metals Silver) and / or absorption (core consists of nanoparticulate metal oxides, in particular doped nanoparticulate tin oxides). In particular the ratio of absorption at 2500 nm to absorption at 600 nm greater than 2.5, in particular larger 3.5.

Farther the particles preferably show an increased reflection, the ratio of the reflection at 2000 nm to the absorption at 300 nm is greater than 1.5, preferably larger 2.0.

The Most particles which are used as additives to control infrared absorption or reflection should be used in the visual field as little influence on the color and / or transparency as possible have, however, a pronounced effect in the infrared for reflection or absorption. The bigger, therefore the relationship between the reflection or absorption in the Infrared range to corresponding values in the visual range, the better this task is solved.

Also The present invention relates to processes for the preparation the particles of the invention, in the simplest Trap comprising the mixture of oligomers and / or polymers, optionally in a solvent or solvent mixture, with the cores and subsequent drying of the mixture.

Preferably the oligomers and / or polymers are precipitated onto the cores.

Preferably becomes the core with an immobilizable LCST and / or UCST polymer or polymer mixture, in particular an amino-functional polyether, optionally mixed in the presence of a solvent. The LCST polymer is dissolved at the temperature below the LCST, while the UCST polymer dissolved above the UCST becomes. As a rule, the LCST temperature is 0.5-90 ° C, preferably 35-80 ° C, while the UCST temperature at 5-90 ° C, especially at 35-60 ° C lies. Thereafter, if appropriate, the addition of additives. Subsequently The temperature is usually about 5 ° C over the LCST is raised or lowered below the UCST, whereby the Polymer precipitates and settles on the particle surface. Finally, the immobilization takes place in the form of a crosslinking of the Polymer on the particle surface instead, the polymer is fixed irreversibly on the particle surface. The Immobilization can z. B. free-radical, cationic, anionic or take place by a condensation reaction. Preferably the LCST or UCST polymers radically or by a condensation reaction networked.

For a radical crosslinking (immobilization) of the deposited Layer in water is preferably potassium peroxodisulfate or ammonium peroxodisulfate in concentration ranges of 1-100% by weight based on the olefinic LCST or UCST polymer used for the assignment used. The networking takes place depending on the LCST or UCST temperature of the polymer at 0-35 ° C. using a catalyst, such as. B. a Fe (II) salt, or at 40-100 ° C by direct thermal decay of the radical initiator. For the production of thermoplastic Polymer layers eliminates the immobilization step. The particles are above the seizure fluid the LCST / or below the UCST z. B. by centrifugation or Filtration separated.

If a solvent or solvent mixture is required in the process according to the invention, the choice of solvent (s) depends on the solubility of the polymer used. Preferably, the solvent is water or a water-miscible organic solvent. To the mixed with water These solvents also include solvents which have miscibility gaps with water. In these cases, the proportions are chosen so that miscibility is present. Examples of suitable solvents are mono- and polyalcohols such as. As methanol, ethanol, n-propanol, isopropanol, cyclohexanol, glycol, glycerol, propylene glycol, polyethylene glycol, polybutylene glycol and the mono- and diethers with methanol, ethanol, propanol and butanol of the polyalkylene glycols; Ether such. For example, tetrahydrofuran, dioxane, 1,2-propanediol propyl ether, 1,2-butan-1-methyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether; Esters such. 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 triamide; Sulfoxides and sulfones such as dimethylsulfoxide and sulfolane; Alkanecarboxylic acid such as formic acid or acetic acid.

The individual LCST and / or UCST polymer layers can also Additives containing the chemical and / or mechanical stability additionally increase or decrease the effect pigments. Suitable additives are for. B. polymerizable monomers, plasticizers, Antioxidants or their mixtures.

Of the Proportion of additives is preferably 0.001 to 150 Wt .-%, in particular 0.05 to 100 wt .-%, based on the used Polymer.

The Additives become the solution of the LCST or UCST polymer preferably mixed as a dispersion, preferably the same Solvents such as the polymer solution used comes and the temperature of the dispersion under the LCST or UCST is lowered. However, it can also be a direct dispersion of the Additives in the LCST or UCST solution take place.

The Drying of the particles according to the invention takes place preferably at low thermal stress, preferably at Temperatures between 50 and 80 ° C.

alternative Drying methods that allow a low thermal load are the drying in a vacuum and / or spray drying. Methods of this kind are sufficiently known to the person skilled in the art.

The Particles of the invention are suitable due to their advantageous properties for a wide range at applications. The invention is therefore also the use the particles of the invention in cosmetics, paints, Colors, plastics, films, in security printing, in security features in documents and identity cards, for seed coloring, for Food coloring or in drug coatings and for the preparation of pigment preparations and dry preparations.

in the Cases of cosmetics are the inventive Particles especially for cosmetics products when it comes to it goes to absorb or reflect heat radiation or as transparent antimicrobial additives. Of course can the particles of the invention in the formulations also with any kind of cosmetic raw and Excipients are combined. These include u. a. oils Greases, waxes, film formers, preservatives and general application technology Properties determining adjuvants, such. As thickeners and rheological Additives such as bentonites, hectorites, silica, ca silicates, Gelatin, high molecular weight carbohydrates and / or surface active Auxiliaries, etc. The particles according to the invention formulations containing the lipophilic, hydrophilic or hydrophobic type. For heterogeneous formulations with discrete aqueous and non-aqueous phases can the particles of the invention in each case only one of the two phases or over both phases are distributed.

The pH values of the aqueous formulations may vary between 1 and 14, preferably between 2 and 11 and more preferably between 5 and 8 are. The concentrations of the invention Particles in the formulation have no limits. You can - ever according to application - between 0.001 (rinse-off products, z. B. shower gels) - 99% are. The invention Particles can also continue with cosmetic agents be combined. Suitable agents are, for. Insect Repellents, UV A / BC protection filters (eg OMC, B3, MBC), anti-aging agents, Vitamins and their derivatives (eg, vitamins A, C, E, etc.), self-tanner (eg DHA, erythrolose and others) and other cosmetic active ingredients such as Bisabolol, LPO, ectoine, emblica, allantoin, bioflavanoids and their derivatives.

When using the particles in paints and paints all known in the art application areas are possible, such. As powder coatings, automotive coatings, inks for gravure, offset, screen or flexographic printing and for coatings in outdoor applications. For example, the paints and paints may become radiation-intensive tend to be physically drying or chemically curing. For the production of printing inks or paints is a variety of binders, z. Example, based on acrylates, methacrylates, polyesters, polyurethanes, nitrocellulose, ethylcellulose, polyamide, polyvinyl butyrate, phenolic resins, maleic resins, starch or polyvinyl alcohol, amine resins, alkyd resins, epoxy resins, polytetrafluoroethylene, polyvinylidene fluorides, polyvinyl chloride or mixtures thereof, in particular water-soluble types. The paints may be powder paints or water- or solvent-based paints, the selection of the paint components is subject to the general knowledge of the skilled person. Common polymeric binders for powder coatings are composed, for example, of polyesters, epoxides, polyurethanes or acrylates.

in principle can the particles of the invention in the formulations also with any kind of other colorants or fillers combined.

In addition, the particles according to the invention can be used for the pigmentation of films and plastics, such. B. for agricultural films, gift wrap, plastic containers and moldings for all known in the art applications. Suitable plastics are all common plastics for the incorporation of the pigment mixtures of the invention, for. As thermosets or thermoplastics. The description of the applications and the usable plastics, processing methods and additives can be found z. In RD 472005 or in R. Glausch, M. Kieser, R. Maisch, G. Pfaff, J. Weitzel, Pearlescent Pigments, Curt R. Vincentz Verlag, 1996, 83 ff. whose disclosure content is included here.

About that In addition, the particles according to the invention are suitable also for use in security printing and security-relevant Characteristics for z. B. forgery-proof cards and ID cards, such as B. tickets, identity cards, banknotes, Checks and check cards as well as other counterfeit-proof ones Documents. In the field of agriculture, the particles can used in seeds and other commodities, beyond that in the food industry for pigmentation of food. For pigmentation of coatings in medicines such. As tablets or dragees are the invention Particles also usable.

The particles according to the invention are also suitable for use in the abovementioned fields of application in blends with all known organic or inorganic dyes and / or pigments. Organic pigments and dyes are, for example, monoazo pigments, disazo pigments, polycyclic pigments, cationic, anionic or nonionic dyes. Inorganic dyes and pigments are, for example, white pigments, colored pigments, black pigments or effect pigments. Examples of suitable effect pigments are metallic effect pigments, pearlescent pigments or interference pigments which as a rule are based on single or multiple coated platelets based on mica, glass, Al ₂ O ₃ , Fe ₂ O ₃ , SiO ₂ , etc. Examples of structures and special properties of the pigments mentioned can be found, for example, in RD 471001 or RD 472005, the disclosure of which is hereby incorporated by reference in the present invention. In addition, luminescent dyes and / or pigments as well as holographic pigments or LCPs (liquid crystal polymers) are suitable as further colorants for blending with the mixtures according to the invention. The particles according to the invention can be mixed in any ratio with commercially available pigments and fillers.

When Fillers are z. B. natural and synthetic Mica, nylon powder, pure or filled melamine resins, Talc, glasses, kaolin, oxides or hydroxides of aluminum, Magnesium, calcium, zinc, biocl, barium sulfate, calcium sulfate, calcium carbonate, Magnesium carbonate, carbon, as well as physical or chemical To name combinations of these substances. Regarding the particle shape there are no restrictions on the filler; it can meet the requirements according to z. B. platelet-shaped, be spherical or acicular.

The particles according to the invention are also suitable for the preparation of flowable pigment preparations and dry preparations containing one or more of the invention Particles, binders and optionally one or more additives. Under Dry preparations are also preparations to understand the 0 to 8 wt .-%, preferably 2 to 8 wt .-%, in particular 3 to 6 wt .-%, of water and / or a solvent or Solvent mixture included. The dry preparations are preferably pellets, granules, chips, sausages or briquettes and have particle sizes of 0.2-80 mm. The dry preparations find particular Application in the production of printing inks and in cosmetic Formulations.

Cosmetics, Varnishes, paints, plastics, films, documents and identity cards, seeds, Food or pharmaceutical coatings, pigment preparations and dry preparations containing the inventive Particles are also the subject of the present invention.

subcombinations The above individual preferred ranges are by the present Invention also included. The following examples are meant to be explain the invention in more detail, but without them limit. Other design options are in Frame of the present invention.

Examples:

Example 1 - Preparation of nanostructured Stirr-In tin dioxide particles (with specific IR absorption)

In a glass reactor 0.5 wt .-% (based on solids Sol) Jeffamine D400, Fa. Huntsmann with a 23 wt .-% -, fluorine doped Tin oxide sol (particle size d50: 20 nm; 10%) and heated to 65 ° C with stirring. After 30 minutes at this temperature, the dispersion is spray-dried or dried by drying at 45 ° C in a vacuum.

Example 2 - Preparation of nanostructured Stirr-In tin dioxide particles (with specific IR absorption)

In a glass reactor 0.5 wt .-% (based on solids Sol) Jeffamine T403, Fa. Huntsmann with a 23 wt .-% -, fluorine doped Zinnoxidsol (analogous to Example 1) and mixed with stirring heated to 65 ° C. After 30 min at this temperature the dispersion is by spray-drying or by drying dried at 45 ° C in a vacuum.

Example 3: - Preparation of a transparent solvent-based paint with inventive Particles from Example 1 or Example 2

1 Wt .-% (based on paint solids) of the invention Particles of Example 1 or 2 are based on a butyl acetate Acrylate / PU-Mischlack (Wörwag) stirred. There are obtained highly transparent paints, which due to the strong absorption of the fluorine doped Zinnoxidnanopartikel in IR range for acceleration of IR curing suitable. The complete redispersion becomes microscopic approved.

Example 4: - Preparation of a Transparent Hydroklarlackes with inventive Particles from Example 1 or Example 2

1 Wt .-% (based on paint solids) of the invention Particles of Example 1 or 2 are in 10 times the amount of water redispersed and by adding Jeffamine D400 pH 8 set. Thereafter, the nanoparticulate dispersion in a 1-component polyurethane-based hydro lacquer stirred. It are highly transparent hydro coatings obtained due to the strong absorption of the fluorine doped Zinnoxidnanopartikel in IR range for acceleration of IR curing suitable. The complete redispersion becomes microscopic approved.

Example 5 - Preparation of nanostructured Stirr-In-Silver particles (with specific IR reflection)

In a glass reactor 0.3 wt .-% (based on solids Sol) Jeffamine T403 from Huntsmann with a 10% by weight silver sol (particle size d50: approx. 30 nm) and heated to 65 ° C. with stirring. After 30 minutes at this temperature, the dispersion is spray-dried or dried by drying at 40 ° C in a vacuum.

Example 6: - Preparation of a Transparent Hydroklarlackes with inventive Particles from example 5

1 Wt .-% (based on paint solids) of the invention Particles from example 3 are converted into a polyurethane-based 1-component Hydrolack stirred. It will be transparent hydro lacquers receive. The complete redispersion becomes microscopic approved.

Comparative Example: Preparation of a dried Zinndioxidsols or Silbersols without modification and Attempt of redispersion in paint systems according to examples 3, 4 and 6

It the corresponding sols are dried in vacuo at 40 ° C. It tries the obtained powder materials in paints of Examples 3, 4 and 6 to redisperse. However, non-transparent, obtained inhomogeneous paints. In the microscope can be a strong agglomeration the particles are detected.

Measurement of physical properties the hydroclearcoat from Example 4

To assess the IR absorptivity, transmission measurements at a wavelength of 800 nm are carried out on the coating films applied on quartz platelets (20 μm layer thickness, UV / VIS spectrometer Lambda 19, Perkin-Elmer). The temperature development of the applied on aluminum sheets samples (layer thickness 50 microns) with IR irradiation at the surface is registered pyrometrically, the temperature of the substrate via a mounted thermocouple. The irradiation is carried out for a period of 20 sec. At an irradiance of 4000 W / m ² with four IR-K lamps from Phillips (intensity maximum at the wavelength of about 1.5 microns at maximum electrical power). Table 1 summarizes the results obtained for different concentrations of the particles of Example 1 and 2 according to the invention. Table 1: Transmission and heating rates of the clearcoat films containing nanostructured particles of the invention according to Example 1 or 2 in different concentrations Concentration nanoparticles /% irradiation Transmission lacquer layer at 800 nm and 20 μm layer thickness /% Heating the paint surface after 20 sec irradiation Heating substrate after 20 sec. 0 99.3 58.6 43.1 0.5 99.2 60.3 43.8 1 98.9 62.1 42.9 2 94.6 67.3 46.3 3 90.4 65.9 48.6

It is clearly seen that when using the inventive Particles in clearcoats a significant increase in temperature the paint matrices compared to the pure clearcoat system IR irradiation occurs, with transmission at 800 nm wavelength decreases with increasing concentration. However, these particles can show a high powder conductivity at the same time further assume that the heat is within the paint layer is distributed more homogeneously. The result is likely in most cases a more homogeneous curing process which is better and also more uniform cross-linked lacquer coatings entails. The slightly lowered surface temperature in conjunction with the increased substrate temperature when used of 3% of the particles according to the invention indicates these homogeneous temperature profiles within the paint layers at.

Powder spectra of the invention Particles according to Example 1, 2 and 5

Using a Perkin-Elmer Lambda 900 spectrophotometer, transmission and absorption spectra are generated in comparison to a coarse F-doped tin oxide (same doping level, average particle size 1 μm) in the spectral range 200-2500 nm. The measurement is carried out in quartz glass cuvettes using an integration sphere 150 mm in diameter, the layer thickness of the powder being 1 mm. The absorption values are determined from the corresponding reflection and transmission values. From the absorption spectra in the 1 and 2 , as well as the transmission spectra in the pictures 3 and 4 shows that the particles according to the invention in the visible visual spectral range have a high transparency, while in the infrared spectral range a strong absorption is observed. For the coarser F-doped tin oxide, although a stronger absorption in the infrared range can be observed, however, these particles have no significant transparency in the visual range. This result confirms with regard to the high transparency that the particles according to the invention consist of nanoparticulate doped particles. The reduced infrared absorption is due to the organic polymer components.

With regard to the particles according to the invention from Example 5, the reflection spectrum for metal particles shows unexpected weak reflections in the UV and visual wavelength range of the light, whereas strong reflections in the IR range ( 5 ).

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• WO 2006/018169 [0002]
• WO 01/60926 A1 [0012]
• WO 03/014229 A1 [0012]

Cited non-patent literature

• - "Polymers", H.-G. Elias, Hüthig and Wepf-Verlag, Zug, 1996, pages 183 ff. [0011]
• - R. Glausch, M. Kieser, R. Maisch, G. Pfaff, J. Weitzel, pearlescent pigments, Curt R. Vincentz Verlag, 1996, 83 ff. [0039]

Claims (21)

Particles comprising a core and a shell comprising oligomers and / or polymers having at least one nitrogen-containing functional group, where the particles are at wavelengths show between 750 and 2500 nm reflection and / or absorption. Particles according to claim 1, characterized characterized in that the particles are in the form of a powder. Particles according to claim 1 or 2, characterized in that it is at the core to nanoparticles is. Particles according to one or more of claims 1 to 3, characterized in that the Core on oxides, hydroxides, sulfides, sulfates, carbonates of Silicon, titanium, zinc, tin, aluminum, indium, copper, antimony, Cerium, cobalt, chromium, nickel, iron, yttrium and / or zirconium or Blends based thereon or based on metals or alloys. Particles according to claim 4, characterized characterized in that the core is based on oxides, hydroxides, sulphides, Sulphates, carbonates of titanium, zinc, aluminum, cerium, cobalt, chromium, Nickel, iron, yttrium, zirconium, metals, alloys and / or or mixtures thereof with oxides or hydroxides of silicon are coated. Particles according to one or more of claims 1 to 5, characterized in that the Core an average particle size, determined by means of dynamic light scattering or transmission electron microscope, from 3 to 200 nm. Particles according to one or more of claims 1 to 6, characterized in that it in the oligomers and / or polymers to thermoplastic oligomers and / or polymers. Particles according to one or more of claims 1 to 7, characterized in that it the oligomers and / or polymers are LCST or UCST oligomers and / or polymers. Particles according to one or more of claims 1 to 8, characterized in that the Oligomers and / or polymers contain at least one amino function. Particles according to one or more of claims 1 to 9, characterized in that the Oligomers and / or polymers are amino-functional polyethers. Particles according to one or more of claims 2 to 10, characterized in that at the particles in the form of a powder the ratio of Absorption at 2500 nm for absorption at 600 nm greater than 2.5 is. Particles according to one or more of claims 1 to 10, characterized in that at the particles in the form of a powder the ratio of Reflection at 2000 nm for reflection at 300 nm greater 1.5 is. Molding compounds comprising cores and oligomers and / or Polymers having at least one nitrogen-containing functional group, wherein the molding compositions at wavelengths between 750 and 2500 nm reflectance and / or absorption. Process for the production of particles according to or more of claims 1 to 12, comprising the mixture of oligomers and / or polymers, optionally in a solvent or solvent mixture, with the cores and then Drying of the mixture. A method according to claim 14, characterized characterized in that the polymers and oligomers precipitated onto the cores become. A method according to claim 14 or 15, characterized in that the solvent or Solvent mixture is selected from mono and polyalcohols, ethers, esters, ketones, amides, sulfoxides, Sulfones and / or alkanecarboxylic acids. Method according to one or more of claims 14 to 16, characterized in that the drying at temperatures of 50 to 80 ° C takes place. Method according to one or more of claims 14 to 17, characterized in that the drying in a vacuum and / or as spray drying. Use of particles according to a or more of claims 1 to 12 in cosmetics, lacquers, paints, Plastics, films, in security applications, for seed coloring, for food coloring or in drug coatings and for the preparation of pigment preparations and dry preparations. Use according to claim 19, characterized in that the particles according to a or more of claims 1 to 12 in admixture with organic or inorganic dyes and / or pigments are present. Cosmetics, paints, paints, plastics, foils, documents and identity cards, seeds, food or pharmaceutical coatings, Containing pigment preparations and dry preparations Particles according to one or more of the claims 1 to 12.