Chemomechanical production of functional colloids

Translation of description of equivalent WO 2004069400 A1

p0001Chemomechanical production of functional colloids

p0002The present invention relates to functional colloids and a process for their preparation.

p0003Colloids have long been known. They can, for example, by sol-gel techniques or by natural processes, such as in water and condensation processes in the gas phase, are formed. For such colloids is typical that they are only stable in aqueous solution, if they are prevented on stabilizing factors at a Aggregatioή. An aggregation can particles by interactions of colloid among themselves, caused for example by van der Waals forces, hydrogen bonds, hydrophobic interactions, dipole-dipole interactions or chemical bonds. Because of the extremely large surface area, the tendency to aggregate is particularly large. Colloidal particles have usually

p0004Dimensions of not more than 0.2 micron.

p0005The stabilization of colloids is usually done by a corresponding zeta potential, ie the formation of a double-charge cloud around the colloids around. This may be due to different work function, or by a loading of the particles with ions or electrons, for example by adjusting the pH. but it can be carried to the surface by the attachment of certain molecules, for example by the addition of humic acids in natural waters. All these processes require, however, that the colloids have been generated by a previous reaction and have set around the colloid conditions that lead to such stabilization.

p0006Other methods for the production of small particles, such as high energy milling, indeed lead to a destruction of the crystal structure down to nanoscale dimensions, but can not prevent the subsequent aggregation. Such aggregated particles as they are manufactured in part by the targeted condensation from the gas phase, can only under very particular certain circumstances be disaggregated. For example it is able to disperse metal particles in oil, because the oil can shift between weakly interacting metal surfaces. Weak interacting metal surfaces are only obtained when the metal particles in a high vacuum, ie, produced under ultraclean conditions, so that no oxide surface is formed. If this is not the case, the particles can no longer disperse practical. Therefore, in the aforementioned high-energy milling processes is a re- dispersion no longer possible on primary crystal size.

p0007As shown above for redispersible in oil metal particles, it is possible only in exceptional cases, such systems to control the process technology. For specific technical process controllability, a method is required which adjusts the colloidal particles in the manufacture of that they are the respective process-related requirements. So it should be possible to provide the colloidal particles in the manufacture with the desired characteristics or functions. For example, it should be possible to stabilize the colloidal particles with respect to the environment, to compatibilize, inerting or reactivate.

p0008With conventional milling equipment can usually only particles in the submicron range and get even with so-called grinding aids that prevent fracture surfaces freshly produced recombine. A crushing on colloid size and in particular a range of 0.002 to 0.05 micron is not possible in general.

p0009The object of the invention was now to prepare colloids, which have an excellent stability against aggregation, wherein the colloidal particles can be very small (preferably less than 0.2 .mu.m, in particular below 0.05 microns) and the features and functions of the colloid or the colloid particles can be adapted to the respective requirements. The object of the invention is surprisingly achieved in that a chemo mechanical reactive comminution process functionalization and simultaneously stabilization against aggregation of the obtained colloid particles is achieved. Accordingly -Sets the present invention provides a process for producing a chemomechanical FunktionskoUoids ready to be mechanically reaktivzerkleinert in which particles in a dispersant in the presence of a modifying agent so that the modifying agent is at least partially chemically bonded to the comminuted colloid particles.

p0010According to the invention functional colloids are in mill units or other Dispergieraggrega- th of particles through the use of generally low molecular weight modifying agents that can form a chemical bond with the particles formed, which have permanently connected to the surface of the particle molecular residues of the modifying agent as functional groups, wherein the average smallest dimension of the functionalized particles as needed down to the range of 0.01 and even 0.002 microns can range. The inventive method makes it possible to obtain stable colloids with average smallest dimensions of preferably not more than 0.2 .mu.m of coarser particles. By modifying the colloid particles with comparatively small molecules that can diffuse to the surfaces newly formed rapidly, aggregation is prevented or inhibited, while also achieving to the respective requirements reasonable fit functionalization of the colloid or colloid particles.

p0011The particles used are to solid particles or solid particles of any suitable material. It may for example be organic (including polymeric) or inorganic particles, inorganic are preferred. Examples of inorganic particles are particles of an element, an alloy or a composite element. The inorganic particles are preferably made of metals, alloys, and in particular of metal compounds and compounds of semiconductor elements, such as Si or Ge, or boron.

p0012Examples of particles composed of an element are particles of carbon, such as carbon black or activated charcoal, of a semiconductor, such as silicon (including technical Si and Prussian and pure silicon) or germanium, or a metal such as iron (including steel), chromium, tin, copper, aluminum, titanium, gold and zinc. Examples of particles of an alloy may be particles made of bronze or brass. Examples of the preferred metal compounds and compounds of semiconductor elements or boron (possibly hydrated) oxides such as ZnO, CdO, SiO₂, GeO₂, TiO₂, ZrO₂, CeO₂, SnO₂, Al₂O₃ (In all modifications, in particular as corundum, boehmite, AlO (OH), also known as aluminum hydroxide), ln₂O₃, La₂O₃, Fe₂O₃, Cu₂O, Ta₂O₅, Nb₂O₅, V₂O₅, Mooe₃ or where₃, Corresponding mixed oxides, such as indium tin oxide (ITO), antimony tin oxide (ATO), fluorine-doped tin oxide (FTO), and those having a perovskite structure, such as BaTi0₃ and PbTiO₃, Chalcogenides, such as sulfides (eg CdS, ZnS, PbS and Ag₂S), selenides (eg GaSe, CdSe and ZnSe) and tellurides (eg ZnTe or CdTe), halides such as AgCl, AgBr, AgI, CuCl, CuBr, Cdi₂ and Pbl₂, Carbides such as CdC₂ or SiC, silicides such as MoSi₂, Arsenide as AlAs, GaAs and GeAs, antimonide, such as InSb, nitrides such as BN, A1N, Si₃N₄ and Ti₃N₄, Phosphides such as GaP, InP, Zn,₃P₂ and Cd₃P₂As well as carbonates, sulfates, phosphates, silicates, zirconocene nate, aluminates and stannates of elements, especially metals or Si, for example, carbonates of calcium and / or magnesium silicates, such as alkali silicates, talc, clays (kaolin), or mica, and sulfates of barium or calcium. Other examples of expedient particles include magnetite, maghemite, spinels (eg MgO AI₂O₃), Mullite, Eskolaite, tialite, SiO₂- TiO₂Or bioceramics, eg Caleium- phosphate and hydroxyapatite. There may be particles of glass or ceramic.

p0013It may be for example be particles, usually for the manufacture of glass (eg. As borosilicate glass, soda or silica glass), glass ceramic or ceramic (eg, based on the oxides SiO₂, BeO, AI₂O₃, ZrO₂ or MgO or the corresponding mixed oxides, electrical and magnetoceramics as titanates and ferrites, or non-oxide ,. such as silicon nitride, silicon carbide, boron nitride or boron carbide) may be used. It can also be particles which serve as fillers or pigments. Technically important fillers include fillers based on SiO₂Such as quartz, cristobalite, Tripolit, novaculite, diatomaceous earth, silica, fumed silicas, precipitated silicas and silica gels, silicates, such as talc, pyrophyllite, kaolin, mica, muscovite, phlogopite vermiculite, wollastonite, and perlite, carbonates such as calcite, dolomite, chalk and synthetic Caiciumcarbonate, soot, sulfates, such as Barite and gypsum, iron mica, glass, aluminum hydroxides, aluminum oxides and titanium dioxide.

p0014Mixtures of these particles may be used. Particularly preferred materials for the particles include metal oxides, silicon oxides and silicates, in particular talc, ZrO₂, AI₂O₃, TiO₂ and SiO₂ or mixtures thereof.

p0015The preparation of the particles employed in this invention can be carried out in a conventional manner, procedure example by flame pyrolysis., Plasma processes, Gasphasenkondensations-, colloid techniques, precipitation, sol-gel processes, controlled nucleation and growth processes, MOCVD processes and (micro) emulsion-procedure. These methods are described in the literature. In particular, ceramic oxide systems are used (by precipitation from solution), as well as salt-like systems or multicomponent systems such as metals (for example, after the reduction of the precipitation method).

p0016Usable particles are. general often also commercially available. Examples of SiO₂Particles are commercial silica products, eg silica sols, as the Levasils®, silica sols from Bayer AG, or pyrogenic silicas, for example. the Aerosil products from Degussa. Of course, all the particles used as fillers can usually be obtained commercially.

p0017The particles can be used in the form of a powder or directly as a dispersion in a dispersant. The particles can also be obtained in the dispersion medium by precipitation of a dissolved precursor in situ.^■

p0018The particle size of the particles used is greater than that of obtained by the process according to the invention colloid particles in general. Although the particle size of the particles used can be selected arbitrarily, are particles having a mean particle diameter of less than 100 microns, preferably less than 10 microns, and an average particle diameter of more than 0.001 micron, preferably more than 0.01 micron, advantageously. As a dispersant, any solvent may be used, provided that the particles to be treated do not or substantially does not dissolve and also compared to the modifying agent used is inert or essentially inert. The suitable dispersant is preferably selected depending on the particles to be treated from water or organic solvents, but they may include inorganic solvents such as carbon disulfide.

p0019A particularly preferred dispersant is water, in particular deionized water. Organic dispersants are both polar and non-polar and aprotic solvents are suitable. Examples of these are alcohols, such as aliphatic and alicyclic alcohols having 1 to 8 carbon atoms (especially methanol, ethanol, n- and i-propanol, butanol, octanol, cyclohexanol), ketones, such as aliphatic and alicyclic ketones having 1 to 8 carbon atoms ( in particular acetone, butanone and cyclohexanone), esters such as ethyl acetate and glycol esters, ethers, such as diethyl ether, dibutyl ether, anisole, dioxane, tetrahydrofuran and tetrahydropyran, glycol ethers such as mono-, di-, tri- and polyglycol ethers, glycols, such as ethylene glycol , diethylene glycol and propylene glycol, amides and other nitrogen compounds, such as dimethylacetamide, dimethylformamide, pyridine, N-methylpyrrolidine and acetonitrile, sulfoxides and sulfones, such as sulfolane and dimethylsulfoxide, nitro compounds such as nitrobenzene, halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, tri- , perchlorethylene, ethylene chloride, chlorofluorocarbons, aliphatic, alicyclic or aromatic hydrocarbons, for example having 5 to 15 carbon atoms, such as pentane, hexane, heptane and octane, cyclohexane, benzines, petroleum ether, methylcyclohexane, decalin, terpene solvents, benzene, toluene and xylenes. Of course, mixtures of such dispersants can be used.

p0020Preferably used organic dispersants are aliphatic and alicyclic alcohols such as ethanol, n- and i-propanol, glycols such as ethylene glycol, and aliphatic, alicyclic and aromatic hydrocarbons, such as hexane, heptane, toluene and o-, m- and p-xylene. Particularly preferred dispersants are ethanol and toluene. The particles are mechanically reaktivzerkleinert in the dispersant in the presence of a modifying agent, ie when the mechanical grinding is a chemical bond of the modifying agent to the particle and the crushed particles by a chemical reaction takes place. Such a reaction under mechanical stress is also known as chemo mechanical response. The skilled worker is aware that there are on the surface of particles usually groups that are not found in this form in the interior of the particles. It is usually at this surface groups to functional groups which are relatively reactive, in general. For example, are on such particles as surface groups residual valences such as hydroxyl groups in, for example, when metal oxide particles, or thiol groups and thio groups, eg with metal sulfides, or amino, amide and imide groups, eg with nitrides.

p0021The modifying agent in particular has at least one functional group that can form a chemical bond with the surface groups of the particles, at least under the conditions of mechanical grinding. The chemical bond is preferably a covalent, ionic or coordinate bond between the modifying agent and the particles but also to hydrogen bonds. A coordinative bond is understood to complex formation. So can take place between the functional groups of the modifying agent and the particles as an acid / base reaction of the Brönsted or Lewis, complex formation or esterification.

p0022In the. functional group comprising the modifying agent, it is preferably carboxylic acid groups, acid chloride groups, ester groups, nitrile and isonitrile groups, OH groups, SH groups, epoxy groups, anhydride groups, acid amide groups, primary, secondary and tertiary amino groups, Si-OH groups , hydrolyzable radicals of silanes (discussed below groups Si-oR) or CH-acidic groups, such as in beta-dicarbonyl compounds.

p0023The modifier can also comprise more than one such functional group, such as. In betaines, amino acids, EDTA In a variant of the method according to the invention, the modifying agent used may also simultaneously act as a dispersant, so that for both the same compound may be employed.

p0024The modifiers are not surfactants. This means that the modifying agent is not in a position in the solvent used as a dispersant, to form micelles, even if it is used in high concentrations. The modifying agent used in the invention, which is different from a surfactant dissolves homogeneously in the solvent used as a dispersant. The modifiers are then presented as discrete molecules or ions homogeneously distributed in the solution. By contrast, surfactants accumulate in a solvent at low concentration at an interface to and reduce the interfacial tension and form with greater concentration micelles are so heterogeneously distributed. The above data relating to the behavior of the pure dispersant. In the presence of the particles, the modifying agent will naturally also according to the invention described chemical interactions with the particles.

p0025While the modifiers as mentioned above at least partially covalent, ionic or coordinative undergo chemical bonds with the surface groups of the particles, the interaction of surfactants in general, non-specific, for example, there are typically adsorption or wetting interactions.

p0026In addition to the at least one functional group which can enter into a chemical bond with the surface of the particle group, the modifying agent has generally a molecular moiety which modifies the properties of the particle to link the modifying agent via the functional group. The molecular radical or a portion thereof may for example be hydrophobic or hydrophilic or carry a second functional group to functionalize in this manner the colloidal particles with respect to the environment, ie, to stabilize, for example, compatibilize, inerting or reactivate. In this way, the colloid particles obtained in the invention are by this molecule residue having a function or surface functionalization provided. In this sense, it is made in the colloids with the modifying agent or surface modifier modified colloidal particles to functional colloids. By the invention it is possible to obtain the desired use of custom function colloids. As principles for coupling to the particles depending on the system, covalent bonds, ionic bonds and complex bonds are present, as well as hydrogen bonds are also suitable.

p0027Hydrophobic molecular residues can be, for example alkyl, aryl, alkaryl, aralkyl or fluorine-containing alkyl groups act that can result in a suitable environment for inerting or rejection. Examples of hydrophilic groups would be hydroxy, alkoxy, or polyether groups. In the optional second functional group of the modifying agent can for example be an acidic, basic or ionic group. It may also be appropriate for a chemical reaction with a selected reactant functional group. The second functional group can be the same, which is also suitable as a functional group capable of binding to the particles, so that reference is made to the examples given there. Other examples of a second functional group would epoxy, acryloxy, methacryloxy, acrylate or methacrylate groups. There may be two or more identical or different such functional groups present.

p0028The modifier preferably has a molecular weight of not more than 500, preferably not more than 400 -and in particular not more than 200. The compounds are preferably liquid under normal conditions. The functional groups that carry these compounds are based primarily on the surface groups of the solid and the desired interaction with the environment. The molecular weight plays an important role for the diffusion to the freshly formed particle surfaces. Small molecules lead to a rapid occupation of the surface and thus reduce the recombination.

p0029Accordingly. Examples of suitable modifying agents saturated or unsaturated mono- and polycarboxylic acids, the corresponding acid anhydrides, Acid chlorides, esters and acid amides, amino acids, imines, nitriles, isonitriles, epoxy compounds, mono- and polyamines, ß-dicarbonyl compounds, silanes, and metal compounds which have a functional group which can react with the surface groups of the particles. Modifier particularly preferably used are silanes, carboxylic acids, amino acids and amines. The carbon chains of these compounds can be interrupted by O, S, barren NH groups. One or more modifiers can be used.

p0030Preferred saturated or unsaturated mono- and polycarboxylic acids (preferably monocarboxylic acids) are those having 1 to 24 carbon atoms, such as formic acid, acetic acid, propionic acid, butyric acid, pentanoic acid, hexanoic acid, acrylic acid, methacrylic acid, crotonic acid, citric acid, adipic acid, succinic acid, glutaric acid, oxalic acid, maleic acid, fumaric acid, itaconic acid and stearic acid and the corresponding Säurenhydride, chlorides, esters and amides, such as caprolactam. Of these, the aforementioned carboxylic acids are also those comprising, whose carbon chain is interrupted by O, S or NH groups. Particularly preferred are ether such as mono- and polyether and the corresponding Säurenhydride, chlorides, esters and amides, such as methoxyacetic acid, 3,6-dioxaheptanoic and 3,6,9-trioxadecanic._,

p0031Examples of preferred mono- and polyamines are those of the formula Q₃,_nNH_nWherein n = 0, 1 or 2 and the radicals Q are independently alkyl of 1 to 12, in particular 1 to 6 and particularly preferably 1 to 4 carbon atoms, eg methyl, ethyl, n- and i-propyl and butyl, and aryl, alkaryl or aralkyl having 6 to 24 Kohlehstoffatomen such as phenyl, naphthyl, tolyl and benzyl, showing, and polyalkyleneamines having the general formula Y₂N (-Z NY)_y-Y, Where Y is independently Q or H, wherein Q is as defined above, y is an integer from 1 to 6, preferably 1 to 3, and Z is preferably 2 or 3 carbon atoms is an alkylene group having 1 to 4. Specific examples are methylamine, dimethylamine. Trimethylamine, ethylamine, aniline, N-methylaniline, diphenylamine, triphenylamine, toluidine, ethylenediamine, diethylenetriamine. Preferred beta-dicarbonyl compounds are those having from 4 to 12, especially 5 to 8 carbon atoms, such as diketones, such as acetylacetone, 2,4-hexanedione, 3,5-heptanedione, acetoacetic acid, acetoacetic acid-C₁-C₄alkyl esters such as ethyl acetoacetate, diacetyl and Acetonylacetone.

p0032Examples of amino acids are beta-alanine, glycine, valine, aminocaproic acid, leucine and isoleucine.

p0033Preferred silanes have at least one non-hydrolyzable group or a hydroxy group, more preferably hydrolyzable organo silanes are used which additionally have at least one non-hydrolyzable radical. Preferred silanes have the general formula (I)

p0034R_aSiX_(4-a) (I) - in which the radicals R are identical or different and represent non-hydrolysable groups, the radicals X are identical or different and are hydrolysable groups or hydroxyl groups and a has the value 1, 2 or 3. The value a is preferred. 1

p0035In the general formula (I), the hydrolysable groups X, which may be the same or different, for example, hydrogen or halogen (F, Cl, Br or I), alkoxy (preferably C_1-6-alkoxy, Such as methoxy, ethoxy, n-propoxy, i-propoxy and butoxy), aryloxy (preferably C₆,₁₀Aryloxy, such as phenoxy), acyloxy (preferably <img id="imgf000012_0001" he="5" wi="25" file="imgf000012_0001.tif" img-format="tif" img-content="drawing" orientation="portrait" inline="no" /> such as acetoxy or propionyloxy), alkylcarboxylic bonyl (preferably C₂,₇Alkylcarbonyl, such as acetyl), amino, monoalkylamino or dialkylamino having preferably 1 to 12, especially 1 to 6 carbon atoms. Preferred hydrolyzable radicals are halogen, alkoxy groups and acyloxy groups. Particularly preferred hydrolysable radicals are C ^ alkoxy, especially methoxy and ethoxy.

p0036The nonhydrolyzable radicals R, which may be identical or different, may be nonhydrolyzable radicals R with or without a functional group. The non-hydrolysable radical R having no functional group is, for example, alkyl (preferably C ^ alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl and tert-butyl, pentyl, hexyl, octyl or cyclohexyl ), alkenyl (preferably C₂,₆- Alkenyl, such as vinyl, 1-propenyl, 2-propenyl and butenyl), alkynyl (preferably C_2-6Alkynyl such as acetylenyl and propargyl), aryl (preferably C₆,₁₀Aryl, such as phenyl and naphthyl) and corresponding alkaryls and aralkyls (for example, tolyl, benzyl and phenethyl). The radicals R and X may optionally have one or more customary substituents, such as halogen or alkoxy. Preferred trialkoxysilanes are. Examples are:

p0037CH₃SiCl₃, CH₃Si (OC₂H₅)₃, CH₃Si (OCH₃)₃, C₂H₅SiCl₃, C₂H₅Si (OC₂H₅)₃, C₂H₅Si (OCH₃)₃, C₃H₇Si (OC₂H₅)₃, (C₂H₅O)₃SiC₃H₆CI, (CH₃)₂SiCl₂, (CH₃)₂Si (OC₂H₅)₂, (CH₃)₂Si (OH)₂, C₆H₅Si (OCH₃)₃, C₆H₅Si (OC₂H₅)₃, C₆H₅CH₂CH₂Si (OCH₃)₃, (C₆H₅)₂SiCl₂.

p0038(C₆H₅)₂Si (OC₂H₅)₂(IC₃H₇)₃SiOH, CH₂= CHSi (OOCCH₃)₃, CH₂= CHSiCI₃, CH₂= CH Si (OC₂H₅)₃, CH₂= CHSi (OC₂H₅)₃, CH₂= CH-Si (OC₂H₄OCH₃)₃, CH₂= CH-CH₂Si (OC₂H₅)₃, CH₂= CH-CH₂Si (OC₂H₅)_3l CH₂= CH-CH₂-Si (OOCCH₃)₃, nC₆H₁₃-CH₂-CH₂Si (OC₂H₅)₃And nC_8thH₁₇-CH₂-CH₂-Si (QC₂H₅)₃,

p0039The non-hydrolysable radical R having a functional group may, for example an epoxide functional group (eg glycidyl or glycidyloxy), ether, amino, monoalkylamino, dialkylamino, optionally substituted anilino, amide, carboxyl -, acrylic, acryloxy, methacrylic, methacryloxy, mercapto, cyano, alkoxy, isocyanato, aldehyde, alkylcarbonyl, acid anhydride, and phosphoric acid group include. These functional groups are bonded via alkylene, alkenylene or arylene bridge groups, which may be interrupted by oxygen or -NH- groups to the silicon atom. The bridging groups preferably contain 1 to 18, preferably 1 to 8 and especially 1 to 6 carbon atoms.

p0040The divalent bridging groups mentioned and any substituents present, as in the alkylamino groups, for example, are derived from the above monovalent alkyl, alkenyl, aryl, alkaryl, or aralkyl from. Of course, the radical R can also have more than one functional group.

p0041Preferred examples of non-hydrolysable radicals R having functional groups are a glycidyl or glycidyloxy a C ^ o alkylene radical such as .beta.-glycidyloxyethyl, γ-Glycidyloxypropyl, δ-Glycidyloxybutyl, ε-Glycidyloxypentyl, ω-Glycidyloxyhexyl, and 2- ( 3,4-epoxycyclohexyl) ethyl, a (meth) acryloxy- (C₁^) - Alkylene radical, for example (meth) acrylic oxymethyl, (meth) acryloxyethyl, (meth) acryloxypropyl or (meth) acryloxybutyl, and a 3-lsocyanatopropylrest. Particularly preferred radicals are γ-Glycidyloxypropyl and (meth) acryloyloxypropyltris. ((Meth) acrylic is methacrylic or acrylic).

p0042Specific examples of corresponding silanes are γ-glycidoxypropyltrimethoxysilane (GPTS), γ-glycidyloxypropyltriethoxysilane (GPTES), 3-lsocyanatopropyltriethoxy- silane, 3-lsocyanatopropyldimethylchlorsilan, 3-aminopropyltrimethoxysilane (APTS), 3-aminopropyltriethoxysilane (APTES), N- (2-aminoethyl ) -3-aminoproyltrimethoxysilan, N- [N '- (2'-aminoethyl) -2-aminoethyl] -3-aminopropyltrimethoxysilane, Hydroxymethyltri- ethoxysilane, 2- [methoxy (polyethyleneoxy) propyl] trimethoxysiIan, bis- (hydroxyethyl) -3 - aminopropyltriethoxysilaπ, N-hydroxyethyl-N-methylaminopropyltriethoxysilan, 3- (meth) acryloxypropyltriethoxysilane and 3- (meth) acryloxypropyltrimethoxysilane.

p0043Furthermore, the use of silanes is also possible to have the at least partially organic radicals, which are substituted with fluorine. Such silanes are described in detail in WO 92/21729 of. For this purpose can be used with at least one nonhydrolyzable radical hydrolyzable silanes having the general formula

p0044Rf (R)_bSiX₍₃,_b) (Ll)

p0045which X and R are as defined in formula (I), Rf is a nonhydrolysable group which has bound 1 to 30 fluorine atoms to carbon atoms, preferably by at least two atoms, preferably an ethylene group, are separated from Si, and B 0, 1 or 2. R is in particular a radical without a functional group, preferably an alkyl group such as methyl or ethyl. Preferably contain the Rf groups 3 to 25 and in particular 3 to 18 fluorine atoms bonded to aliphatic Carbon atoms are bonded. Rf is preferably a fluorinated alkyl group having 3 to 20 carbon atoms, and examples are CF₃CH₂CH₂-, C₂F₅CH₂CH₂- CY₆F₁₃CH₂CH₂-, IC₃F₇OCH₂CH₂CH₂- CY_8thF₁₇CH₂CH₂- And nC₁₀F₂₁-CH₂CH₂-.

p0046Examples of usable Fluorosilanes are CF₃CH₂CH₂SiCl₂(CH₃), CF₃CH₂CH₂SiCl (CH₃)₂, CF₃CH₂CH₂Themselves₃) (OCH₃)₂, C₂F₅-CH₂CH₂-SiZ₃, nC₆F₁₃- CH₂CH₂SiZ₃, nC_8thF₁₇-CH₂CH₂-SiZ₃, nC₁₀F₂₁-CH₂CH₂-SiZ₃ with (Z = OCH₃, OC₂H₅ or Cl), iC₃F₇O-CH₂CH₂CH₂-SiCI₂(CH₃) NC₆F₁₃-CH₂CH₂-Si (OCH₂CH₃)₂, nC₆F₁₃-CH₂CH₂- SiCl₂(CH₃) And nC₆F₁₃-CH₂CH₂-SiCI (CH₃)₂,

p0047The silanes can be prepared by known methods; see. W. Noll, "Chemistry and Technology of Silicones", Verlag Chemie GmbH, Weinheim / Bergstrasse (1968).

p0048Examples of metal compounds that have a functional group are metal compounds of a metal M from main groups III to V and / or transition groups II to IV of the Periodic Table of Elements. Preferred compounds of Al, Ti or Zr. Examples include R-MX ^ (M = Ti or Zr and c = 1, 2, 3), wherein X and R are as defined above in formula (I) are defined wherein one R or more R may together also form a complexing agent, such as for example, a .beta.-dicarbonyl compound or a (mono) carboxylic acid, can stand. Preferred are zirconium and titanium tetraalkoxides in which a part of the alkoxy groups has been replaced by a complexing agent, such as a .beta.-dicarbonyl compound or a carboxylic acid, preferably a monocarboxylic acid.

p0049The substances used according may be blended in any order with each other. The mixture may be directly in the crusher or in advance in a separate container, such as a mixer occur. Preferably, but no other additives are added, ie, the reactive size reduction is to be subjected to mixture of at least one dispersant, at least one modifying agent, which can be the same in a special case with the dispersant, and the particles, which are preferably consists of particles of one material , Examples of additives that are optionally added are defoamers, pressing aids, organic Binders, photocatalysts, preservatives and rheological additives. The addition of additives is only necessary when they are needed for further processing. Therefore, these additives can also be added after the processing according to the invention. An advantage for a previous addition may lie in the obtained by the grinding homogeneous mixture.

p0050In carrying out the process of the invention the content of particles strongly depends on the type of particle from, but it is generally up to 60 Vol .-% of the suspension, usually it is between 50 and 0.5 vol .-%, preferably 30 to 1 Vol .-% and in particular from 25 2.5 vol .-% of the dispersion. The rest of the suspension is made up of dispersants and modifiers. In this case, the weight ratio of particles / modifiers generally from 100: 1 to 100: 35, in particular from 100: 2 to 100: 25 and more preferably 100: 4 to 100: 20th

p0051The present in the grinding chamber volume ratio particles / grinding media inevitably results from the solids content of the suspension and the degree of filling used at grinding balls and the bulk density of the grinding balls.

p0052Mechanical comminution generally takes place in mills, compounders, roll mills or eg in nozzle jet dispersers instead. Suitable comminution machines for mechanical comminution include homogenizers, turbomixer, mills with loose grinding, such as ball, rod, drum, cone, tube, autogenous, planetary, vibratory and stirred mills, Scherwalzenkneter, mortar mills, colloid mills and roller mills. Comminution, z. B. may consist of milling and homogenization is carried out preferably at room temperature. The duration depends on the nature of the mixture and the crusher used.

p0053Mills are preferably used with loose grinding. The grinding tools or grinding bodies are for example spheres, rods or short cylindrical pieces. The container takes example from a rotating, planetary or shaking or the grinding medium is moved with an agitator. Particularly preferred mills are attrition mills with a moving agitator and milling balls as grinding media.

p0054Mills are preferably used with very small grinding media, thereby being capable of applying small-sized shear forces. step for the Feinstdispergier- are preferably not with a diameter of not more than 2.5 mm, more preferably not more than 1, 5 mm and particularly preferably not more than 1, 0 mm and not smaller than 0.05 mm, more preferably smaller grinding media than 0.07 mm and particularly preferably not less than 0.09 mm. The grinding media are usually made of steel, plastic, hard metal, AI₂O₃, Agate, zirconium, ZrO₂, Y ZrO₂, Ce-ZrO₂, Mg-ZrO₂, Glass, SiC, SiN or mixtures of these materials, particularly preferred Mahlkörpermaterialien are stabilized zirconium oxides, zirconium silicate and steel.

p0055The crushing may also take place in a two or multistage process. You can, for example from an upstream comminution (pre-cutting) and a subsequent fine grinding made, wherein the modifier in each stage or only in at least one stage, as the last, can be present. For example, can be connected upstream of the milling with grinding media grinding step with coarser grinding bodies in order to achieve the optimum, efficient starting particle size on Feinstzerkleinerungsschritt.

p0056The preferred particle size (average diameter or average smallest dimension) for the Feinstzerkleinerungsprozess is 30 to 1000 nm, preferably 50 to 500 nm and particularly preferably 60 to 150 nm.

p0057Depending on the type of crusher used, in particular a mill, such as filler levels are from 50 to 100% of grinding media used, preferably filling ratios are 60-98%, particularly preferably from 70 to 95%. The comminution process in agitating ball mills takes place eg at speeds of the agitator 900-5000 U / min, preferred speeds 1000-4500 U / min ,. particularly preferred speeds 2000-4200 U / min.

p0058The milling time depends in particular on the type of particles used from, it may be from several minutes up to days, for example 10 minutes to 5 days, preferably between 1 hour and 12 hours.

p0059The reactive size reduction can be supported by additional input of energy (in addition to the mechanical energy applied), for example by means of microwave and / or ultrasonic, these two methods can also be used simultaneously. The energy input in the dispersion is particularly preferably directly in the crusher, but can also take place outside the crusher in the product cycle.

p0060The inventive process is preferably carried out at a temperature from room temperature (about 20 ° C) to the boiling point of the dispersing medium. By appropriate temperature control (cooling) of the grinding chamber of the mill these respective working temperatures are adjustable.

p0061The method can not only continuously in Einpassagenbetrieb, multi-pass operation (pendulum method) or circulation process or discontinuously in batch operation to be performed.

p0062By crushing according to the invention, the reactive modifier is chemically bonded to the comminuted particles. Here, at least a portion of the modifier molecules employed is bound to the particles. The component which is chemically bonded, for example, depends on the nature of the particles, the amount relative to the particles, the obtained size and thereby the available surface of the particles used.

p0063The inventive combination of the use of modifying agents and mechanical comminution functional colloids can be produced, having firmly bound to the colloidal particles, chemical components. Hereby it is possible even to produce colloidal particles having a smallest dimension down in a range of 0.01 to 0.002 microns.

p0064The average smallest dimension (average diameter, average height or width) of the particles produced by the method according to the invention is not more than 0.2 micron, preferably not more than 0.1 microns and more preferably no more than 0.05 microns. The comminution may result even particles having an average smallest dimension of up to not more than 0.01, and even no more than 0.002 microns as required.

p0065The average smallest dimension, for example, is the average height for spherical particles, the average particle diameter and for platelet-shaped particles. Under the average particle diameter is in the present specification, the d₅₀Value understood the volume distribution. The skilled person is known method for determining these particle sizes as well as the details for these procedures. Examples of suitable measurement methods are dynamic laser light scattering (eg with an ultrafine particle analyzer (UPA)), X-ray disc centrifuge or quantitative image analysis of electron micrographs.

p0066If desired, the function of colloid particles can be recovered from the obtained colloid function by removal of the dispersant, which can be used as a powder. In order to remove any known in the art method may be used, such as evaporation, centrifugation or filtration. Another possibility for the separation is set by methods known to those skilled in the isoelectric point in order to obtain a flocculation which can then be filtered off. On the obtained functional colloid particles are on the surface of the chemically bound modifying agent molecules through their functionality you can control the properties of the particles. The colloid particles can be subsequently taken up again in the same or other suitable dispersing agent, with no or shows relatively low aggregation, so that the average particle diameter can be essentially retained.

p0067The function colloids or the function of colloid particles can be worked up further by methods known in the art. It can for example be reacted with other flächenmodifikatoren upper, it can be dispersed in organic or aqueous solvents and soluble polymers, oligomers or monomers, or organic sols, or additives, for example those mentioned above, can be admixed. Such mixtures, or workups functional colloids according to the invention or functional colloid particles as such can be used, for example for the production of coatings or for other applications.

p0068Examples of the use of the functional colloids, the function of colloid particles or of mixtures which include these functional colloids or colloid particles function, include the production of ceramic moldings, films, membranes and coatings, or of polymeric matrix compounds. The coatings or layers for various purposes are, for example, as coatings with low energy surfaces or abrasion resistant, microbicidal, photocatalytic, mikrostrukturierbare or microstructured, holographic, conductive, UV-absorbing, photochromic and / or electrochromic layers.

p0069The following examples serve to further illustrate the present invention.

p0070Examples

p0071Examples 1 to 5 were carried out using a mill (Drais Perl Mill PML-H / V). Specifications: grinding chamber gross volume: 1, 2 I, agitator, and Mahlraumauskleidung Mahlkörperabtrennung (sieve cartridge) of zirconium oxide, motor rating main drive 4,0 kW, motor speed main drive 3,000 U / min, agitator speed 900- 4100 rev / min. EXAMPLE 1 In a reaction vessel, 600 ml of toluene, 50 g of talcum powder (&lt;10 micron, BET surface area 14 m²/ G) and 5 g of methyltrimethoxysilane added and mixed for 30 minutes with stirring. The resulting mixture is filled into an agitating, 1-.300 g milling balls (zirconium silicate, ball diameter 0.6 - 1. 0 mm) contains. Milling takes place at 4,000 rev / min for 4 hours. The mill is then emptied with 2 l of toluene. The solvent is removed by centrifugation (4000 rev / min, 15 min). The remaining powder is at 130 ° C for 24 h dried in a vacuum drying cabinet and has a BET surface area of ​​200 m²/G.

p0072EXAMPLE 2 In a reaction vessel, 600 ml of toluene, 50 g of talcum powder (&lt;10 micron, BET surface area 14 m²/ G) and 7.2 g of phenyltrimethoxysilane added and mixed for 30 minutes with stirring. The resulting mixture is filled into an agitating 1,300 g milling balls (zirconium silicate, ball diameter 0.6 - 1. 0 mm) contains. Milling takes place at 4,000 rev / min for 4 hours. The mill is then emptied with 2 l of toluene. The solvent is removed by centrifugation (4000 rev / min, 15 min). The remaining powder is at 130 ° C for 24 hours dried in a vacuum drying cabinet, and has a BET surface area of ​​194 m²/G.

p0073EXAMPLE 3 In a reaction vessel, 600 ml of toluene, 50 g of talcum powder (&lt;10 micron, BET surface area 14 m²/ G) and 8.9 g of methyl acrylic acid [3-trimethoxysilylpropyl] was added for 30 minutes while stirring mixed. The resulting mixture is filled into an agitating 1,300 g milling balls (zirconium silicate, ball diameter 0.6 - 1. 0 mm) contains. Milling takes place at 4,000 r / min for 4 hours. The mill is then emptied with 2 l of toluene. The solvent is removed by centrifugation (4000 rev / min, 15 min). The remaining powder is at 130 ° C for 24 hours dried in a vacuum drying cabinet, and has a BET surface area of ​​153 m²/G.

p0074EXAMPLE 4 In a reaction vessel, 600 ml of toluene, 50 g of talcum powder (&lt;10 micron, BET surface area 14 m²/ G) and 5 g of 2- [methoxy (polyethyleneoxy) propyl] trimethoxysilane gege- ben and mixed for 30 minutes while stirring. The resulting mixture is filled into an agitating 1,300 g milling balls (zirconium silicate, ball diameter 0.6 - 1. 0 mm) contains. Milling takes place at 4,000 r / min for 4 hours. The mill is then emptied with 2 l of toluene. The solvent is removed by centrifugation (4000 rev / min, 15 min). The remaining powder is at 130 ° C for 24 hours dried in a vacuum drying cabinet, and has a BET surface area of ​​101 m²/G.

p0075COMPARATIVE EXAMPLE In a reaction vessel, 600 ml of toluene and 50 g of talc powder (&lt;10 micron, BET surface area 14 m²/ G) was added and mixed for 30 minutes with stirring. The resulting mixture is filled into an agitating 1,300 g milling balls (zirconium silicate, ball diameter 0.6 - 1. 0 mm) contains. Milling takes place at 4,000 r / min for 4 hours. The mill is then emptied with 2 l of toluene. The solvent is removed by centrifugation (4000 rev / min, 15 min). The remaining powder is at 130 ° C for 24 hours dried in a vacuum drying cabinet, and has a BET surface area of ​​18 m²/G.

p0076EXAMPLE 5 In a reaction vessel, 1,350 ml of toluene, 150 g of talc powder (&lt;10 micron, BET surface area 14 m²/ G) and 15 g of methacrylic acid [3-trimethoxysilylpropyl] was added for 30 minutes while stirring mixed. The mixture is filled by 90% with grinding balls (zirconium oxide, ball diameter 0.4 mm) agitator ball mill (Netzsch LabStar LS1) pumped continuously. It is 2 min milled at 3,000 U / h. The mill is then emptied with 2 l of toluene. The solvent is removed by centrifugation (4000 rev / min, 15 min). The remaining powder is at 130 ° C for 24 h in a vacuum drying cabinet, and has a BET surface area of ​​180 rτr7g.

p0077EXAMPLE 6 In a reaction vessel 1000 ml of distilled water, 400 g of zirconium oxide are (BET surface 150 ± 10 m²/ G) and 60 g of 3,6,9-trioxadecanoic added and mixed for 30 minutes with stirring. The resulting mixture is in an agitating 4 h milled (Drais Perl Mill PML-H V, zirconia Mahlraumaus- clothing, grinding chamber gross 1, 2 I, 4100 U / min, 1,700 g milling balls, zirconium silicate, ball diameter 0,3 - 0,4 mm, continuous operation in circular mode). The colloid thus obtained contains particles having an average particle diameter of d₅₀ = 0.0118 .mu.m (UPA).

p0078,. EXAMPLE 7 In a reaction vessel 880 ml of distilled water, 800 g of zirconium oxide are (BET surface 150 ± 10 m²/ G) and 120 g of 3,6,9-trioxadecanoic added and mixed for 30 minutes with stirring. The resulting mixture is in an agitating 4.5 h milled (Drais Perl Mill PML-HΛ, zirconia Mahlraumauskleidung, grinding chamber gross 1, 2 I, 4100 U / min, 1,700 g milling balls, zirconium silicate, ball diameter 0,3 - 0,4 mm , continuous operation in circular mode). The colloid thus obtained contains particles having an average particle diameter of d₅₀ = 0.0123 .mu.m (UPA).

p0079EXAMPLE 8 In a reaction vessel, 150 ml of distilled water, 1,500 ml of isopropanol, 800 mg zirconia (BET surface 150 ± 10 m²/ G), 40 g of 3,6,9-trioxadecanoic acid and 38.6 g of methacrylic acid added and mixed for 30 minutes with stirring. The resulting mixture is in an agitating 4.5 h milled (Drais Perl Mill PML-HΛ /, zirconia Mahlraumauskleidung, grinding chamber gross 1, 2 I, 4100 U / min, 1,700 g milling balls, zirconium silicate, ball diameter 0,3 - 0,4 mm, continuous operation in circular mode). The colloid thus obtained contains particles having an average particle diameter of d₅₀ = 0.0110 .mu.m (UPA).

p0080EXAMPLE 9 In a reaction vessel, 800 ml of distilled water, 400 g of zirconium oxide (Degussa, ZrO₂-VP, BET surface area 40 ± 10 m²/ G (per manufacturer), washed powder) and 60 g 3,6,9-trioxadecanic added and mixed for 30 minutes while stirring. The resulting mixture is in an agitating 4.5 h milled (Drais Perl Mill PML-H / V, zirconia Mahlraumauskleidung, gross 1 grinding chamber, 2 I, 4100 U / min, 1,700 g milling balls, zirconium silicate, ball diameter 0.3 -, 0 4 mm, continuous operation in circular mode). The colloid obtained containing particles having an average particle diameter of d₅₀ = 0.023 .mu.m (UPA), BET surface area 75 m²/G.

p0081EXAMPLE 10 In a reaction vessel, 800 ml of distilled water, 400 g of zirconium oxide (Tosoh, ZrO₂/ TZ-O, BET surface area 14 m²/ G (per manufacturer)) and 60 g 3,6,9-Trioxa- decanoic acid added and mixed for 30 min with stirring. The mixture is milled in a stirred ball mill (Drais Perl Mill PML-HΛ /, zirconia Mahlraumauskleidung, grinding chamber gross 1, 2 I, 4100 U / min, 1,700 g milling balls, zirconium silicate, .Kugeldurchmesser 0,3 - 0,4 mm, continuous operation in circular mode). The colloid thus obtained contains particles having an average particle diameter of d₅₀ = 0.073 microns (UPA), BET surface area 48 m²/G.

p0082EXAMPLE 11 In a reaction vessel, 1,180 ml of distilled water, 800 g of aluminum oxide (Sumitomo, AKP53, BET surface 9 - 15 meter²where / g (per manufacturer)) and 40 g 3,6,9 trioxadecanic and mixed with stirring for 14 hours. The resulting mixture is in an agitating 12 h milled (Drais Perl Mill PML HΛ /, zirconia Mahlraumauskleidung, gross 1 grinding chamber, 2 I, 4100 U / min, 1,700 g milling balls, zirconium silicate, ball diameter 0.3 - 0.4 mm continuous operation in circular mode). After 4 hours and 5.5 hours respectively 20 g 3,6,9-trioxadecanic be added. The colloid obtained has a BET surface area of ​​54 m²/ G, d₅₀ = 0.044 microns (X-ray disk centrifuge).

p0083EXAMPLE 12 In a reaction vessel, 1,035 ml of ethanol, 201 g of titanium dioxide (Sachtleben, Hombitec RM300, BET surface area 60 m²/ G (per manufacturer), washed powder) 20.16 g^'APTES and 4.8 ml of distilled water and mixed for 5 minutes while stirring. The resulting mixture is in an agitating 4 h milled (Drais Perl Mill PML-HΛ /, zirconia Mahlraumauskleidung, .Mahlraumvolumen gross 1, 2 I, 4100 U / min, 1,700 g milling balls, zirconium silicate, ball diameter 0,3 - 0,4 mm , continuous operation in the circulation process). through subsequent Solvent Abtausch by centrifugation and washing twice with distilled water (pH = 7) is obtained by redispersion in water with pH 4.5 a colloid having an average particle diameter of d₅₀ = 0.063 (UPA), BET surface area 99 m²/G.