Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82B—NANOSTRUCTURES FORMED BY MANIPULATION OF INDIVIDUAL ATOMS, MOLECULES, OR LIMITED COLLECTIONS OF ATOMS OR MOLECULES AS DISCRETE UNITS; MANUFACTURE OR TREATMENT THEREOF
  • B82B3/00—Manufacture or treatment of nanostructures by manipulation of individual atoms or molecules, or limited collections of atoms or molecules as discrete units
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G9/00—Compounds of zinc
  • C01G9/02—Oxides; Hydroxides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
  • C08K3/20—Oxides; Hydroxides
  • C08K3/22—Oxides; Hydroxides of metals
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K9/00—Use of pretreated ingredients
  • C08K9/02—Ingredients treated with inorganic substances
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK  ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
  • C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
  • C09C1/04—Compounds of zinc
  • C09C1/043—Zinc oxide
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y40/00—Manufacture or treatment of nanostructures
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/60—Particles characterised by their size
  • C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/25—Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
  • Y10T428/256—Heavy metal or aluminum or compound thereof
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]
  • Y10T428/2991—Coated
  • Y10T428/2993—Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]

Definitions

• the invention relates to modified zinc oxide nanoparticles, a production process for such particles and their use for UV protection.
• inorganic nanoparticles inorganic nanoparticles in a polymer matrix can not only the mechanical properties, such. Impact resistance, of the matrix, but also changes their optical properties, e.g. wavelength-dependent transmission, color (absorption spectrum) and refractive index.
• particle size plays an important role, since the addition of a substance with a refractive index which differs from the refractive index of the matrix, inevitably leads to light scattering and ultimately to opacity.
• the decrease in the intensity of radiation of a defined wavelength when passing through a mixture shows a strong dependence on the diameter of the inorganic particles.
• Suitable substances would therefore have to absorb in the UV range, appear as transparent as possible in the visible range and be readily incorporated into polymers. Although numerous metal oxides absorb UV light, they are poorly soluble for the reasons given above without impairing the mechanical or optical properties Incorporate visible light properties into polymers.
• nanomaterials for dispersion in polymers requires not only the control of particle size but also the surface properties of the particles.
• Simply mixing (e.g., by extrusion) hydrophilic particles with a hydrophobic polymer matrix results in uneven distribution of the particles throughout the polymer and also in their aggregation.
• their surface must therefore be at least hydrophobically changed.
• the nanoparticulate materials show a great tendency to form agglomerates, which remain even with a subsequent surface treatment.
• a method can be obtained in which in a step a) an inverse
• Emulsion containing one or more water-soluble precursors for the nanoparticles or a melt is prepared by means of a random copolymer of at least one monomer having hydrophobic radicals and at least one monomer having hydrophilic radicals and in a step b) particles are produced.
• these particles are ZnO particles having a particle size of 30 to 50 nm with a coating of a copolymer consisting essentially of lauryl methacrylate (LMA) and hydroxyethyl methacrylate
• HEMA The ZnO particles are produced, for example, by basic precipitation from an aqueous zinc acetate solution.
• International patent application WO 2000/050503 describes a process for the preparation of zinc oxide gels by basic hydrolysis of at least one zinc compound in alcohol or an alcohol-water mixture, which comprises ripening the precipitate initially formed during the hydrolysis until the zinc oxide is completely flocculated, this precipitate is then compressed into a gel and separated from the supernatant phase.
• the particles can be coated with SiO 2 by reaction with tetraethoxysilane in the presence of ammonia by the so-called “Stöber process", although cloudy dispersions form, and also the coating of dispersed ZnO particles with ortho-phosphate or tributyl phosphate or Diisooctylphosphinic acid is described here.
• a first subject of the present invention is therefore zinc oxide nanoparticles having an average particle size determined by means of particle correlation spectroscopy (PCS) or
• the ZnO nanoparticles according to the invention which are dispensed by the process described can also be isolated. This is achieved by removing the alcohol from step a) until it dries.
• Another object of the present invention is a corresponding method for the production of zinc oxide nanoparticles with an average particle size determined by particle correlation spectroscopy (PCS) or transmission electron microscope in the range of 3 to 50 nm, dispersed in an organic solvent, characterized in that a step a) one or more precursors for the nanoparticles in an alcohol are converted to the nanoparticles, in a step b) the growth of the nanoparticles is terminated by the addition of at least one modifier which is precursor for silica, if in the UV / VIS Spectrum of the reaction solution, the absorption edge has reached the desired value and optionally in step c), the alcohol from step a) is removed and replaced by another organic solvent.
• PCS particle correlation spectroscopy
• the salt formed during ZnO formation is filtered off either in step b) or in step c).
• the particles according to the invention are distinguished by high absorption in the UV range, particularly preferably in the UV-A range, combined with high transparency in the visible range. in the In contrast to many zinc oxide qualities known from the prior art, these properties of the particles according to the invention, dispersed in an organic solvent, do not change during storage or only to a negligible extent.
• the particle size is in particular by means of
• PCS Particle correlation spectroscopy
• the photocatalytic activity of untreated zinc oxide is reduced by applying the silica shell.
• silica means a material consisting essentially of silicon dioxide and / or silicon hydroxide, it also being possible for the Si atoms to carry organic radicals which are already present in the modifiers.
• the photocatalytic activity of ZnO is reduced to such an extent that it is determined by the oxidation of 2-propanol to acetone upon irradiation with UV light of an Hg medium pressure immersion lamp (for example, type Haereus TQ718; 500W). less than 0.20 * 10 '3 mol / (kg * min) over one hour, preferably even less than 0.10 * 10 -3 mol / (kg * min), and most preferably no longer detectable in the experiment. (Test conditions: 250 mg of ZnO particles suspended in 350 ml of 2-propanol at room temperature during the irradiation bubbled oxygen through the dispersion.)
• the modifier which is precursor for silica is preferably a trialkoxysilane or a tetraalkoxysilane, wherein Alkoxy preferably represents methoxy or ethoxy, particularly preferably methoxy.
• Particularly preferred according to the invention is the use of tetramethoxysilane as modifier.
• the addition of the modifier takes place, as described above, depending on the desired absorption edge, but usually 1 to 50 minutes after the start of the reaction, preferably 10 to 40 minutes after the start of reaction and more preferably after about 30 min.
• the location of the absorption edge in the UV spectrum is dependent on the particle size in the initial phase of zinc oxide particle growth. It is at the beginning of the reaction at about 300 nm and shifts in the course of time in the direction of 370 nm.
• the growth can be interrupted at any point. It is desirable to shift as close as possible to the visible region (from 400 nm) in order to achieve UV absorption over as wide a range as possible. If the particles are allowed to grow too far, the solution becomes cloudy.
• the desired absorption edge is therefore in the range of 300-400 nm, preferably in the range up to 320-380 nm. Values between 355 and 365 nm have proven to be optimal.
• nanoparticles obtainable by this method can be particularly easily and uniformly redispersed, and in particular an undesirable impairment of the transparency of such dispersions in visible light can be largely avoided.
• zinc oxide nanoparticles having an average particle size are determined by means of
• Particle correlation spectroscopy in the range of 3 to 50 nm, the particle surface of which is modified with silica, dispersed in an organic solvent object of the invention, characterized in that they are obtainable by a process, wherein in a step a) one or more precursors for the nanoparticles are converted into the nanoparticles in an alcohol, in a step b) the growth of the nanoparticles is terminated by the addition of at least one modifier, which is a precursor for silica, when the absorption edge has reached the desired value in the UWVIS spectrum of the reaction solution, in a step c) the silica coating is modified by addition of at least one further surface modifier selected from the group consisting of organofunctional silanes, quaternary ammonium compounds, phosphonates, phosphonium and sulfonium compounds or mixtures out and optionally in step d) the alcohol from Schri a) and replaced with another organic solvent.
• PCS Particle correlation spectroscopy
• step d) The isolation of the nanoparticles thus prepared takes place in step d) by removing the alcohol from step a) until it has dried.
• the optionally resulting salt load can be removed by filtration both in step b), c) and in step d).
• Suitable surface-modifying agents are, for example, organofunctional silanes, quaternary ammonium compounds, phosphonates, phosphonium and sulfonium compounds or mixtures thereof.
• the surface modifiers are selected from the group of organofunctional silanes.
• the described requirements for a surface modifier fulfill in particular according to the invention a primer bearing two or more functional groups.
• One group of the coupling agent chemically reacts with the oxide surface of the nanoparticle.
• Alkoxysilyl groups for example methoxy-, ethoxysilanes
• halosilanes for example chloro
• acidic groups of phosphoric acid esters or phosphonic acids and phosphonic acid esters are suitable here.
• the groups described are linked to a second, functional group.
• the functional group is preferably acrylate, methacrylate, vinyl, amino, cyano, isocyanate, epoxy, carboxy or hydroxy groups.
• Silane-based surface modifiers are described, for example, in DE 40 11 044 C2.
• Phosphoric acid-based surface modifiers include i.a. as Lubrizol® 2061 and 2063 from LUBRIZOL (Langer & Co.).
• Suitable silanes are, for example, vinyltrimethoxysilane, aminopropyltriethoxysilane, N-ethylamino-N-propyldimethoxysilane, isocyanatopropyltriethoxysilane, mercaptopropyltrimethoxysilane, vinyltriethoxysilane,
• Particularly preferred is 3-methacryloxypropyltrimethoxysilane.
• silanes are commercially available e.g. available from ABCR GmbH & Co., Düsseldorf, or the company Sivento Chemie GmbH, Dusseldorf.
• Vinylphosphonic acid or vinylphosphonic acid diethyl ester can also be listed here as adhesion promoters (manufacturer: Hoechst AG, Frankfurt am Main).
• the surface modification agent is an amphiphilic silane according to the general formula (R) 3Si-Sp-A h pB h b, where the radicals R may be identical or different and represent hydrolytically removable radicals, Sp is either -O- or straight-chain or branched alkyl having 1-18 C atoms, straight-chain or branched alkenyl having 2-18 C atoms and one or more double bonds, straight-chain or branched alkynyl having 2-18 C atoms and one or more
• Cycloalkyl having 3-7 C atoms which may be substituted by alkyl groups having 1-6 C atoms
• a hP represents a hydrophilic block
• Bhb means a hydrophobic block and preferably wherein at least one reactive functional group on A hp and / or B hb bound present.
• the amphiphilic silanes contain a head group (R) 3 Si, where the radicals R may be the same or different and represent hydrolytically removable radicals.
• the radicals R are the same.
• Suitable hydrolytically removable radicals are, for example, alkoxy groups having 1 to 10 C atoms, preferably having 1 to 6 C atoms, halogens, hydrogen, acyloxy groups having 2 to 10 C atoms and in particular having 2 to 6 C atoms or NRV groups, the Radicals R 'may be the same or different and are selected from hydrogen or alkyl having 1 to 10 C atoms, in particular having 1 to 6 C atoms.
• Suitable alkoxy groups are, for example, methoxy, ethoxy, propoxy or butoxy groups. Suitable halogens are in particular Br and Cl. Examples of acyloxy groups are acetoxy or propoxy groups. Oximes are also suitable as hydrolytically removable radicals. The oximes may hereby be substituted by hydrogen or any organic radicals.
• the radicals R are preferably alkoxy groups and in particular methoxy or ethoxy groups.
• the group SP is either -O- or straight-chain or branched alkyl having 1 -18 C atoms, straight-chain or branched alkenyl having 2-18 C atoms and one or more double bonds, straight-chain or branched alkynyl having 2-18 C atoms and one or more triple bonds, saturated, partially or fully unsaturated cycloalkyl having 3-7 C atoms, which may be substituted by alkyl groups having 1-6 C atoms.
• the dC 18 -alkyl group of Sp is, for example, a methyl, ethyl, isopropyl, propyl, butyl, sec-butyl or tert-butyl, and also pentyl, 1-, 2- or 3- Methylbutyl, 1,1-, 1,2 or 2,2-dimethylpropyl, 1-ethylpropyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl or tetradecyl ,
• it can be perfluorinated be, for example, as difluoromethyl, tetrafluoroethyl, hexafluoropropyl or octafluorobutyl.
• a straight-chain or branched alkenyl having 2 to 18 carbon atoms, where a plurality of double bonds may also be present, is, for example, vinyl, allyl, 2- or 3-butenyl, isobutenyl, sec-butenyl, furthermore 4-pentenyl, iso-pentenyl, Hexenyl, heptenyl, octenyl, -CgHi 6 , -
• Ci 0 H 18 to -Ci 8 H 34 preferably allyl, 2- or 3-butenyl, isobutenyl, sec-butenyl, furthermore preferred is 4-pentenyl, iso-pentenyl or hexenyl.
• a straight-chain or branched alkynyl having 2 to 18 C atoms, wherein a plurality of triple bonds may also be present is, for example, ethynyl, 1- or 2-propynyl, 2- or 3-butynyl, furthermore 4-pentynyl, 3-pentynyl, hexynyl, Heptynyl, octynyl, -CgHi 4 , -Ci 0 Hi 6 to - Ci 8 H 32 , preferably ethynyl, 1- or 2-propynyl, 2- or 3-butynyl, 4-pentynyl, 3-pentynyl or hexynyl.
• Unsubstituted saturated or partially or fully unsaturated cycloalkyl groups having 3-7 C atoms may be cyclopropyl, cyclobutyl,
• Phenyl, cycloheptenyl, cyclohepta-1, 3-dienyl, cyclohepta-1, 4-dienyl or cyclohepta-1, 5-dienyl be substituted with C 1 - to C 6 - alkyl groups.
• the spacer group Sp is followed by the hydrophilic block A hp .
• This may be selected from nonionic, cationic, anionic or zwitterionic hydrophilic polymers, oligomers or groups.
• the hydrophilic block is ammonium, sulfonium, phosphonium groups, alkyl chains with carboxyl, sulfate and phosphate groups.
• Side groups which may also be present as a corresponding salt, partially esterified anhydrides with free acid or salt group, OH-substituted alkyl or cycloalkyl chains (eg sugar) with at least one OH group, NH- and SH-substituted alkyl or cycloalkyl chains or mono , di- or oligo-ethylene glycol groups.
• the length of the corresponding alkyl chains can be 1 to 20 C atoms, preferably 1 to 6 C atoms.
• nonionic, cationic, anionic or zwitterionic hydrophilic polymers, oligomers or groups can be prepared from corresponding monomers by polymerization according to methods generally known to the person skilled in the art.
• Suitable hydrophilic monomers contain at least one dispersing functional group which consists of the group consisting of
• Quaternizing agents can be converted into cations, and cationic groups, and / or
• the functional groups (i) are selected from the group consisting of carboxylic acid, sulfonic acid and phosphonic acid groups, acidic sulfuric acid and
• Phosphoric ester groups and carboxylate, sulfonate, phosphonate, sulfate ester and phosphate ester groups the functional groups (ii) from the group consisting of primary, secondary and tertiary amino groups, primary, secondary, tertiary and quaternary ammonium groups, quaternary phosphonium groups and tertiary sulfonium groups, and the functional groups (iii) from the group, consisting of omega-hydroxy and omega-alkoxy-poly (alkylene oxide) -1-yl groups selected.
• the primary and secondary amino groups may also serve as isocyanate-reactive functional groups.
• hydrophilic monomers having functional groups (i) are acrylic acid, methacrylic acid, beta-carboxyethyl acrylate, ethacrylic acid, crotonic acid, maleic acid, fumaric acid or itaconic acid; olefinically unsaturated sulfonic or phosphonic acids or their partial esters; or maleic acid mono (meth) acryloyloxyethyl ester, succinic acid mono (meth) acryloyloxyethyl ester or phthalic acid mono (meth) acryloyloxyethyl ester, in particular acrylic acid and
• Groups (ii) are 2-aminoethyl acrylate and methacrylate or allylamine.
• Groups (iii) are omega-hydroxy or omega-methoxy-polyethylene oxide-1-yl, omega-methoxy-polypropylene oxide-1-yl, or omega-methoxy-poly (ethylene oxide-co-polypropylene oxide) -1-yl acrylate or methacrylate, and hydroxy-subsitituted ethylene, acrylates or methacrylates, such as hydroxyethyl methacrylate.
• Suitable monomers for the formation of zwitterionic hydrophilic polymers are those in which a betaine structure occurs in the side chain.
• the side group is selected from - (CH 2 ) m - (N + (CH 3) 2 ) - (CH 2 ) n -SO 3 -, - (CH 2 ) m - (N + (CH 3 ) 2 ) - (CH 2 ) n-PO 3 2 -, - (CH 2 ) m - (N + (CH 3 ) 2 ) - (CH 2 ) n -O-PO 3 2 - or - (CH 2 ) m - (P + (CH 3) 2 ) - (CH 2 ) n -SO 3 - I where m is an integer in the range from 1 to 30, preferably from the range 1 to 6, particularly preferably 2, and n is an integer from the range of 1 to 30, preferably from the range 1 to 8, particularly preferably 3.
• At least one structural unit of the hydrophilic block has a phosphonium or sulfonium radical.
• LMA lauryl methacrylate
• DMAEMA dimethylaminoethyl methacrylate
• Copolymer consisting essentially of lauryl methacrylate (LMA) and hydroxyethyl methacrylate (HEMA) is used, which can be prepared in a known manner by free radical polymerization with AIBN in toluene.
• LMA lauryl methacrylate
• HEMA hydroxyethyl methacrylate
• the hydrophilic monomers it is to be noted that it is preferable to combine the hydrophilic monomers having functional groups (i) and the hydrophilic monomers having functional groups (ii) so as not to form insoluble salts or complexes.
• the hydrophilic monomers having functional groups (i) or functional groups (ii) can be arbitrarily combined with the hydrophilic monomers having functional groups (iii).
• the monomers having the functional groups (i) are particularly preferably used.
• the neutralizing agents for the anionic functional groups (i) are selected from the group consisting of ammonia, trimethylamine, triethylamine, tributylamine, dimethylaniline, diethylaniline, triphenylamine, dimethylethanolamine, diethylethanolamine, methyldiethanolamine, 2-aminomethylpropanol, dimethylisopropylamine, dimethylisopropanolamine, triethanolamine , Diethylenetriamine and triethylenetetramine, and the neutralizing agents for the cation-convertible functional groups (ii) selected from the group consisting of sulfuric acid, hydrochloric acid, phosphoric acid, formic acid, acetic acid, lactic acid, dimethylolpropionic acid and citric acid.
• the hydrophilic block is selected from mono-di- and triethylene glycol structural units.
• the block B hb is based on hydrophobic groups or, like the hydrophilic block, on the polymerization of suitable hydrophobic monomers.
• suitable hydrophobic groups are straight-chain or branched alkyl having 1-18 C atoms, straight-chain or branched alkenyl having 2-18 C atoms and one or more double bonds, straight-chain or branched alkynyl having 2-18 C atoms and one or more triple bonds , saturated, partially or fully unsaturated cycloalkyl having 3-7 C atoms, which may be substituted by alkyl groups having 1-6 C atoms. Examples of such groups are already mentioned in advance.
• aryl, polyaryl, aryl-C 1 -C 6 -alkyl or esters having more than 2 C atoms are suitable.
• the groups mentioned may also be substituted, in particular with halogens, with perfluorinated groups being particularly suitable.
• Aryl-C 1 -C 6 -alkyl is, for example, benzyl, phenylethyl, phenylpropyl, phenylbutyl, phenylpentyl or phenylhexyl, where both the phenyl ring and the alkylene chain, as described above, may be partially or completely substituted by F, particularly preferably benzyl or phenylpropyl.
• hydrophobic olefinically unsaturated monomers examples include
• substantially acid group-free esters of olefinically unsaturated acids such as (meth) acrylic acid, crotonic acid, ethacrylic acid,
• Crotonic acid, ethacrylic acid, vinylphosphonic acid or Vinylsulfonklareester in particular cyclohexyl, isobomyl, dicyclopentadienyl, octahydro-4,7-methano-1 H-inden-methanol or tert-butylcyclohexyl (meth) acrylate l- crotonate, -ethacrylate, vinyl phosphonate or vinyl sulfonate.
• minor amounts of higher functional (meth) acrylic acid, crotonic acid or ethacrylic alkyl or cycloalkyl esters such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, butylene glycol, pentane-1, 5-diol, hexane-1, 6 -diol-, octahydro-4,7-methano-1H-indenedimethanol or cyclohexane-1, 2-, -1, 3- or -1, 4-diol-di (meth) acrylate, trimethylolpropane tri (meth) acrylate or pentaerythritol tetra (meth) acrylate and the analogous ethacrylates or crotonates.
• minor amounts of higher-functional monomers (1) are amounts which do not lead to crosslinking or gelation of the polymers;
• Hydroxyalkyl esters of alpha.beta.-olefinically unsaturated carboxylic acids such as hydroxyalkyl esters of acrylic acid, methacrylic acid and ethacrylic acid, in which the hydroxyalkyl group contains up to 20 carbon atoms, such as 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 3-hydroxybutyl, 4-hydroxybutyl acrylate, methacrylate or ethacrylate; 1, 4-bis (hydroxymethyl) cyclohexane, octahydro-4,7-methano-1H-indenedimethanol or methylpropanediol monoacrylate, monomethacrylate, monoethacrylate or monocrotonate; or reaction products of cyclic esters, e.g. epsilon-caprolactone and these hydroxyalkyl esters;
• olefinically unsaturated alcohols such as allyl alcohol
• Allyl ethers of polyols such as trimethylolpropane monoallyl ether or pentaerythritol mono-, di- or triallyl ether.
• the higher functionality monomers are generally used only in minor amounts. In the context of the present invention, minor amounts of higher-functional monomers are amounts which do not lead to crosslinking or gelation of the polymers,
• Formaldehyde adducts of aminoalkyl esters of alpha-beta-olefinically unsaturated carboxylic acids and of alpha-beta-unsaturated carboxylic acid amides such as N-methylol and N, N-dimethylolaminoethyl acrylate, aminoethyl methacrylate, acrylamide and methacrylamide; such as
• Acryloxysilane and hydroxyl-containing olefinically unsaturated monomers prepared by reacting hydroxy-functional silanes with epichlorohydrin 30 and then Reaction of the intermediate with an alpha, beta-olefinically unsaturated carboxylic acid, in particular acrylic acid and methacrylic acid, or their hydroxyalkyl esters;
• vinyl esters of alpha-branched monocarboxylic acids having 5 to 18 carbon atoms in the molecule such as the vinyl esters of Versatic® acid sold under the trademark VeoVa®;
• cyclic and / or acyclic olefins such as ethylene, propylene, but-1-ene, pent-1-ene, hex-1-ene, cyclohexene, cyclopentene, norbornene,
• amides of alpha.beta.-olefinically unsaturated carboxylic acids such as (meth) acrylamide, N-methyl-, N, N-dimethyl, N-ethyl, N, N-diethyl, N-propyl, NN-dipropyl, N-butyl, N, N-dibutyl and / or N, N-cyclohexylmethyl (meth) acrylamide;
• monomers containing epoxide groups such as the glycidyl esters of acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, maleic acid, fumaric acid and / or itaconic acid;
• vinyiaromatic hydrocarbons such as styrene, vinyltoluene or alpha-alkylstyrenes, especially alpha-methylstyrene;
• nitriles such as acrylonitrile or methacrylonitrile
• Vinyl halides such as vinyl chloride, vinyl fluoride, vinylidene dichloride,
• Vinylidene vinylidene
• Vinylamides such as N-vinylpyrrolidone
• Vinyl ethers such as ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether and vinyl cyclohexyl ether
• vinyl esters such as vinyl acetate, vinyl propionate, and vinyl butyrate
• allyl compounds selected from the group consisting of allyl ethers and esters, such as propyl allyl ether, butyl allyl ether, ethylene glycol diallyl ether, trimethylolpropane triallyl ether, or allyl acetate or allyl propionate;
• allyl ethers and esters such as propyl allyl ether, butyl allyl ether, ethylene glycol diallyl ether, trimethylolpropane triallyl ether, or allyl acetate or allyl propionate
• Siloxane or polysiloxane monomers which may be substituted with saturated, unsaturated, straight-chain or branched alkyl groups or other hydrophobic groups already mentioned above.
• polysiloxane macromonomers having a number average molecular weight Mn of 1,000 to 40,000 and an average of 0.5 to 2.5 ethylenically unsaturated double bonds per molecule such as polysiloxane macromonomers having a number average molecular weight Mn of 1,000 to 40,000 and an average of 0.5 have up to 2.5 ethylenically unsaturated double bonds per molecule; in particular polysiloxane macromonomers which have a number-average molecular weight Mn of 2,000 to 20,000, more preferably 2,500 to 10,000 and in particular 3,000 to 7,000 and an average of 0.5 to 2.5, preferably 0.5 to 1, 5, ethylenically unsaturated double bonds per molecule, as in DE 38 07 571 A 1 on pages 5 to 7, DE 37 06 095 A 1
• carbamate or allophanate group-containing monomers such as acryloyloxy or methacryloyloxyethyl, propyl or butyl carbamate or allophanate; other examples of suitable monomers which Carbamate groups are described in the patents US 3,479,328 A 1, US 3,674,838 A 1, US 4,126,747 A 1, US 4,279,833 A 1 or US 4,340,497 A 1 described.
• polymerization of the above-mentioned monomers can be carried out in any manner known to those skilled in the art, e.g. by polyaddition or cationic, anionic or radical polymerizations. Polyadditions are preferred in this context, because they can be combined with each other in a simple manner different types of monomers, such as epoxides with dicarboxylic acids or isocyanates with diols.
• amphiphilic silanes according to the present invention have an HLB value in the range of 2-19, preferably in the range of 4-15.
• the HLB value is defined as
• HLB value is calculated theoretically and results from the mass fractions of hydrophilic and hydrophobic groups.
• An HLB value of 0 indicates a lipophilic compound, a chemical compound with an HLB value of 20 has only hydrophilic moieties.
• amphiphilic silanes of the present invention are further characterized in that at least one reactive functional group is bound to A hp and / or Bhb.
• the reactive functional group is preferably located at the hydrophobic block B hb , where it is particularly preferably bound to the end of the hydrophobic block in front.
• the head group (R) 3 Si and the reactive functional group have the greatest possible distance. This allows a particularly flexible design of the chain lengths of the blocks A h p and B h t > , without significantly restricting the possible reactivity of the reactive groups, for example with the surrounding medium.
• the reactive functional group can be selected from silyl groups with hydrolytically removable radicals, OH, carboxy, NH, SH groups, halogens or double bonds containing reactive groups, such as acrylate or vinyl groups.
• Suitable silyl groups with hydrolytically removable radicals have already been described in advance in the description of the head group (R) 3 Si.
• the reactive group is an OH group.
• Zinc salts can generally be used as precursors for the nanoparticles. Preference is given to using zinc salts of the carboxylic acids or halides, in particular zinc formate, zinc acetate or zinc propionate and also zinc chloride. Zinc acetate or its dihydrate is very particularly preferably used according to the invention as precursor.
• the reaction of the precursors with the zinc oxide takes place according to the invention preferably in the basic, wherein in a preferred process variant, a hydroxide base, such as LiOH, NaOH or KOH is used.
• a hydroxide base such as LiOH, NaOH or KOH is used.
• step a) is carried out in the process according to the invention in an alcohol, in particular methanol or ethanol being suitable.
• methanol has proved to be a particularly suitable solvent.
• Suitable organic solvents or solvent mixtures for the dispersion of the nanoparticles according to the invention in addition to the alcohols in which they are initially obtained according to the method are typical paint solvents.
• Typical lacquer solvents are, for example, alcohols, such as methanol or ethanol, ethers, such as diethyl ether, tetrahydrofuran and / or dioxane, esters, such as butyl acetate or hydrocarbons, such as toluene, petroleum ether, halogenated.
• Hydrocarbons such as dichloromethane, or even commercially available products such as solvent naphtha or products based on Shellsol, a high-boiling hydrocarbon solvent, for example Shellsol A, Shellsol T, Shellsol D40 or Shellsol D70.
• the particles according to the invention preferably have an average particle size determined by means of particle correlation spectroscopy (PCS) as described above or transmission electron microscope from 5 to 20 nm, preferably from 7 to 15 nm.
• the distribution of particle sizes is narrow, ie, the d50, and in particularly preferred embodiments, even the d90 is preferably in the above ranges of 5 to 15 nm, or even 7 to 12 nm.
• this dispersion or synonymous suspension used
• a layer thickness of 10 mm containing 0.001 wt .-%, wherein the wt .-% - indication is determined by the investigation method, at 320 nm less than 10%, preferably less than 5% and at 440 nm greater than 90%, preferably greater than 95%.
• the measurement was carried out in a UV vis spectrometer (Varian Carry 50).
• the concentration of the solution is adapted to the device sensitivity (dilution to about 0.001 wt .-%).
• reaction temperature can be selected in the range between room temperature and the boiling point of the selected solvent.
• rate of reaction can be controlled by appropriate selection of the reaction temperature, the starting materials and their concentration and the solvent, so that it does not cause any difficulties for the skilled person, the speed be controlled so that a control of the reaction process by UV spectroscopy is possible.
• emulsifiers are optionally ethoxylated or propoxylated, longer-chain alkanols or alkylphenols having different degrees of ethoxylation or propoxylation (for example adducts having from 0 to 50 mol of alkylene oxide).
• Dispersing aids can also be used to advantage, preferably water-soluble high molecular weight organic compounds having polar groups, such as polyvinylpyrrolidone, copolymers of vinyl propionate or acetate and vinylpyrrolidone, partially saponified copolymer of acrylic ester and acrylonitrile, polyvinyl alcohols having different residual acetate content, cellulose ethers, gelatin, block copolymers, modified starch, low molecular weight, carbon and / or sulfonic acid-containing polymers or mixtures of these substances can be used.
• polar groups such as polyvinylpyrrolidone, copolymers of vinyl propionate or acetate and vinylpyrrolidone, partially saponified copolymer of acrylic ester and acrylonitrile, polyvinyl alcohols having different residual acetate content, cellulose ethers, gelatin, block copolymers, modified starch, low molecular weight, carbon and / or sulfonic acid-containing
• Particularly preferred protective colloids are polyvinyl alcohols having a residual acetate content of less than 40, in particular 5 to 39 mol .-% and / or vinylpyrrolidone ⁇ / inylpropionat copolymers having a vinyl ester content of less than 35, in particular 5 to 30 wt .-%.
• reaction conditions such as temperature, pressure, reaction time
• reaction time can be specifically set the desired property combinations of the required nanoparticles.
• the corresponding setting of these parameters does not cause any difficulties for the skilled person.
• the nanoparticles according to the invention, dispersed in an organic solvent or isolated, are used in particular for UV protection in polymers.
• the particles protect either the polymers themselves against degradation by UV radiation, or the polymer preparation containing the nanoparticles is - again used as a UV protection for other materials - for example in the form of a protective film or applied as a lacquer layer.
• Polymer formulations consisting essentially of at least one polymer or a paint formulation, which are characterized in that the polymer nanoparticles according to the invention contains, are therefore further objects of the present invention.
• Polymers in which the isolated nanoparticles according to the invention can be well incorporated are in particular polycarbonate (PC), polyethylene terephthalate (PETP), polyimide (PI), polystyrene (PS), polymethyl methacrylate (PMMA) or copolymers which contain at least a portion of one of the polymers mentioned ,
• the incorporation can be carried out by conventional methods for the preparation of polymer preparations.
• the polymer material can be mixed with isolated nanoparticles according to the invention, preferably in an extruder or kneader.
• a particular advantage of the particles according to the invention with silane coating consists in the fact that only a small energy input is required for the homogeneous distribution of the particles in the polymer in comparison with the prior art.
• the polymers may also be dispersions of polymers, such as, for example, paints or lacquer preparations.
• the incorporation can be done by conventional mixing processes.
• polymer preparations according to the invention comprising the isolated nanoparticles or the dispersions according to the invention are also particularly suitable for coating surfaces, for example wood, plastics, fibers or glass.
• the surface or the underlying material under the coating for example, protect against UV radiation.
• the conversion to zinc oxide and the growth of the nanoparticles can be monitored by UV spectroscopy. Already after a minute
• TMOS tetramethylorthosilicate
• the potassium acetate formed in the reaction is separated by ultrafiltration.
• a stable, transparent suspension is obtained, which contains ZnO according to UV spectroscopy and X-ray diffraction.
• the particle diameter, after particle correlation spectroscopic examination with a Malvern Zetasizer (PCS), is 4 -12 nm with a d50 of 6-7 nm and a d90 from 5 to 10 nm. Furthermore, no reflections of potassium acetate are visible in the X-ray diagram.
• Example 2V A comparative experiment without addition of the TMOS solution shows continued particle growth and becomes cloudy after 14 h.
• Example 2 To the product dispersion according to Example 2 are added and stirred for an additional 18 h at 50 0 C 50 0 C 20 ml of the amphiphilic silane prepared in Example 3a.
• a stable, transparent suspension is obtained which, according to UV spectroscopy and X-ray diffraction, contains ZnO.
• the diameter of the particles is according to photon correlation spectroscopic Examination with a Malvern Zetasizer (PCS) 4 -12 nm with a d50 of 6 - 7 nm and a d90 of 5 - 10 nm.
• PCS Malvern Zetasizer
• a new measurement after 10 days gave the same values within the scope of the measuring accuracy. Agglomeration of the particles can thus be excluded. Furthermore, no reflections of potassium acetate are visible in the X-ray diagram.
• Example 5 The suspension of Example 5 is applied under reduced pressure until

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