DE102007040638A1 - Composites with good mechanical and tribological properties, useful e.g. for injection molding, comprise fine titanium dioxide particles in (thermo)plastic and/or epoxy resin matrix - Google Patents

Abstract

New composites (I), of filler and pigment in polymer matrix type, contain (a) at least one of thermoplastics, high performance plastics and/or epoxy resins and (b) titanium dioxide (TiO 2) of average crystal size d 5 0 less than 350 (preferably 3-50) nm, optionally having an (in)organically modified surface. An independent claim is included for the production of (I), by producing a masterbatch from (b) and part of (a), then diluting with (a) while dispersing.

Description

object The invention is a titanium dioxide-containing composite, a method for its production and the use of this composite.

Out the application of conventional fillers and pigments, too Called additives, in polymeric systems it is known that the Art and the strength the interactions between the particles of the filler or pigments and the polymeric matrix the properties of a composite affected. Through targeted surface modification, the Interactions between the particles and the polymeric matrix modified and thus the properties of the system of fillers and pigments in a polymeric matrix, hereinafter also composite called, changed become. A usual Type of surface modification is the functionalization of particle surfaces using alkoxyalkylsilanes. The surface modification can serve the compatibility increase the particle with the matrix. In addition, by the appropriate Selection of functional groups also a binding of the particles be reached to the matrix.

A second way to improve the mechanical properties of polymeric materials is the use of ultrafine particles. US-B-6,667,360 discloses polymeric composites containing 1 to 50 wt% of nanoparticles with particle sizes of 1 to 100 nm. As nanoparticles metal oxides, metal sulfides, metal nitrides, metal carbides, metal fluorides and metal chlorides are proposed, wherein the surface of these particles is unmodified. As the polymeric matrix, there are mentioned epoxides, polycarbonates, silicones, polyesters, polyethers, polyolefins, synthetic rubber, polyurethanes, polyamide, polystyrenes, polyphenylenes oxides, polyketones and copolymers, and mixtures thereof. In the US-B-6,667,360 The disclosed composites should have improved mechanical properties, in particular tensile properties and scratch resistance, compared to the unfilled polymer.

One Another disadvantage of the described in the prior art, with fillers modified composites are inadequate for many applications mechanical properties.

task The object of the present invention is to overcome the disadvantages of the prior art Technology to overcome.

Especially The object of the invention is to provide a composite provide, compared to composites from the prior art significantly improved flexural moduli, flexural strengths, tensile moduli, tensile strengths, Fracture toughness, Fracture toughness, impact strength and wear rates has.

This is for certain applications of composite materials, for example in the Automotive, aircraft or aviation sector of great importance. So are reduced wear rates in plain bearings, gears or roll and piston coatings desired. Especially these components should have a long life and thus prolonged Lead times of machines. In synthetic fibers such as PA6, PA66 or PET, the tensile strengths be improved.

Surprisingly The object has been achieved by composites according to the invention with the characteristics of Main claim solved. Preferred embodiments are characterized in the subclaims.

Surprisingly, the mechanical and tribological properties of polymer composites were also greatly improved when using precipitated, surface-modified titanium dioxide with crystallite sizes d ₅₀ smaller than 350 nm (measured by the Debye-Scherrer method). Surprisingly, a physical bond between particle and matrix has a particularly favorable effect on the improvement of the mechanical and tribological properties of the composite.

The composite according to the invention contains a polymeric matrix and 0.1 to 60% by weight precipitated titanium dioxide particles with an average crystallite size d _{50 of} less than 350 nm (measured by the Debye-Scherrer method). The crystallite size d ₅₀ is preferably less than 200 nm, more preferably from 3 to 50 nm. The titanium dioxide particles may have a spherical or rod-like morphology.

Farther can the composites of the invention the person skilled in per se known ingredients, for example mineral fillers, Glass fibers, stabilizers, process additives (also protective systems called) z. As dispersants, release agents, antioxidants, antiozonants et al.), pigments, flame retardants (eg aluminum hydroxide, antimony trioxide, Magnesium hydroxide, u. a.), vulcanization accelerator, vulcanization retarder, zinc oxide, stearic acid, Sulfur, peroxide and / or plasticizer.

One Composite according to the invention For example, in addition up to 80 wt .-%, preferably 10 to 80 wt .-%, mineral fillers and / or glass fibers, up to 10 wt .-%, preferably 0.05 to 10 wt .-% Stabilizers and process additives (eg dispersing aids, release agents, Antioxidants, u. a.), up to 10% by weight of pigment and up to 40% by weight. Flame retardants (eg aluminum hydroxide, antimony trioxide, magnesium hydroxide, u. a.).

One Composite according to the invention For example, 0.1 to 60 wt .-% titanium dioxide, 0 to 80 wt .-% mineral fillers and / or glass fibers, 0.05 to 10 wt .-% stabilizers and process additives (eg, dispersing aids, release agents, antioxidants, and the like), 0 to 10% by weight of pigment, 0 to 40% by weight of flame retardant (eg. Aluminum hydroxide, antimony trioxide, magnesium hydroxide, and the like. a.).

The polymeric matrix can be made of a thermoplastic, a high performance plastic or an epoxy resin. As thermoplastic materials are, for example, polyester, polyamide, PET, polyethylene, polypropylene, Polystyrene, its copolymers and blends, polycarbonate, PMMA, or polyvinyl chloride suitable. As high performance plastics are PTFE, fluoroplastics (eg FEP, PFA, etc.), PVDF, polysulfones (e.g. PES, PSU, PPSU, etc.), polyetherimide, liquid crystalline polymers and Polyether ketones suitable. Furthermore, epoxy resins are suitable as polymeric matrix.

The composite according to the invention may be from 0.1 to 60% by weight precipitated, surface-modified Titanium dioxide, 0 to 80% by weight of mineral fillers and / or glass fibers, 0.05 to 10% by weight of stabilizers and process additives (eg dispersing aids, Release agents, antioxidants, u. a.), 0 to 10 wt .-% pigment, 0 up to 40% by weight of flame retardant (eg aluminum hydroxide, antimony trioxide, Magnesium hydroxide, u. a.).

According to the invention ultrafine Titanium dioxide particles are used, an inorganic and / or an organic surface modification have.

The inorganic surface modification ultrafine titanium dioxide is typically compounds, containing at least two of the following elements: aluminum, Antimony, barium, calcium, cerium, chlorine, cobalt, iron, phosphorus, Carbon, manganese, oxygen, sulfur, silicon, nitrogen, Strontium, vanadium, zinc, tin and / or zirconium compounds or salts. Examples include sodium silicate, sodium aluminate and aluminum sulfate.

The inorganic surface treatment The ultrafine titanium dioxide takes place in aqueous slurry. The reaction temperature should preferably not exceed 50 ° C. The pH of the suspension is, for example, using of NaOH adjusted to pH values in the range greater than 9. Under strong stir then the aftertreatment chemicals (inorganic compounds), preferably water-soluble inorganic compounds such as aluminum, antimony, Barium, calcium, cerium, chlorine, cobalt, iron, phosphorus, carbon, Manganese, oxygen, sulfur, silicon, nitrogen, strontium, Vanadium, zinc, tin and / or zirconium compounds or salts added. The pH and the amounts of aftertreatment chemicals are chosen according to the invention such that the latter completely in Water dissolved present. The suspension is stirred vigorously, so that the aftertreatment chemicals are homogeneous in the suspension distribute, preferably for at least 5 minutes. In the next Step, the pH of the suspension is lowered. As advantageous has been found to lower the pH slowly and with vigorous stirring. The pH is particularly advantageous within 10 to 90 minutes lowered to levels of 5 to 8. After that closes According to the invention, a maturing time, preferably a maturation time of about one hour. The temperatures should preferably be 50 ° C. do not exceed. The watery Suspension is then washed and dried. For drying the ultrafine, surface-modified Titanium dioxide, for example, the spray-drying, freeze-drying offer and / or the Mahltrocknung. Depending on the drying process can be a subsequent Milling the dried powder may be necessary. The grind can be carried out according to known methods.

According to the invention are the following Compounds particularly suitable as organic surface modifiers: Polyethers, silanes, polysiloxanes, polycarboxylic acids, fatty acids, polyethylene glycols, polyesters, Polyamides, polyalcohols, organic phosphonic acids, titanates, zirconates, Alkyl and / or arylsulfonates, alkyl and / or aryl sulfates, alkyl and / or aryl phosphoric acid esters.

The Production of organic surface-modified Titanium dioxide can be carried out by processes known per se.

On the one hand it concerns the surface modification in aqueous or solvent-containing Phase. On the other hand, the organic component can be applied to the particle surface by direct spraying and subsequent mixing / milling.

According to the invention suitable organic compounds with vigorous stirring and / or while a dispersion added to a titania suspension. there The organic modifications are via chemisorption / physisorption to the particle surface bound.

When Organic compounds are particularly suitable compounds selected from the group of alkyl and / or arylsulfonates, alkyl and / or aryl sulfates, Alkyl and / or aryl phosphoric acid esters or mixtures of at least two of these compounds, wherein the Alkyl or aryl radicals be substituted by functional groups can. Also can the organic compounds are fatty acids which may have functional groups have. Also mixtures of at least two such compounds can be used.

For example be used: alkylsulfonic acid salt, Sodium polyvinyl sulfonate, sodium N-alkyl benzene sulfonate, sodium polystyrenesulfonate, Sodium dodecyl benzene sulphonate, sodium lauryl sulphate, sodium cetyl sulphate, Hydroxylamine sulfate, triethanolammonium lauryl sulfate, phosphoric acid monoethylmonobenzyl ester, Lithium perfluorooctane sulfonate, 12-bromo-1-dodecanesulfonic acid, sodium 10-hydroxy-1-decanesulfonate, Sodium carrageenan, sodium 10-mercapto-1-cetane sulfonate, sodium 16-ceten (1) sulfate, oleyl cetyl alcohol sulfate, oleic acid sulfate, 9,10-dihydroxystearic acid, isostearic, Stearic acid, oleic acid.

The organically modified titanium dioxide can either form directly the present aqueous Paste may be used or dried before use. The drying can be carried out according to known methods. For drying especially the use of convection dryers, spray dryers, Grinders, freeze dryers and / or pulsation dryers. However, other dryers are likewise usable according to the invention. Depending on Drying process may be a subsequent grinding of the dried Be necessary powder. The grinding can according to known methods carried out become.

Have according to the invention the surface modified Titanium dioxide particles optionally one or more functional groups, for example, one or more hydroxy, amino, carboxyl, epoxy, Vinyl, methacrylate and / or isocyanate groups, thiols, alkylthiocarboxylates, Di- and / or polysulfidic groups.

Prefers are surface modifiers, the above a functional group bound to the titanium dioxide particles and over another functional group interacts with the polymeric matrix.

The surface modifiers can chemically and / or physically bound to the particle surface be. The chemical bond can be covalent or ionic. When physical bond are possible dipole-dipole or van der Waals bonds. Prefers is the attachment of surface modifiers via covalent Ties or over physical dipole-dipole bonds.

Own according to the invention the surface modified Titanium dioxide particles have the ability to work through the surface modifiers partially or completely a chemical and / or physical bond to enter the polymeric matrix. As chemical bonding types are covalent and ionic bonds are suitable. As physical bond types dipole-dipole and van der Waals bonds are suitable.

Preferably may for the preparation of the composite according to the invention first Masterbatch are prepared, preferably 5-80 wt.% Titanium dioxide contains. This masterbatch can then either diluted with the crude polymer or mixed with the other ingredients of the recipe and possibly again be dispersed.

to Production of the composite according to the invention can also choose a procedure be, with the titanium dioxide first in organic substances especially in polyols, polyglycols, polyethers, dicarboxylic acids and their derivatives, AH salt, caprolactam, paraffins, phosphoric esters, hydroxy carboxylic acid esters, Cellulose, styrene, methyl methacrylate, organic diamides, epoxy resins and plasticizers (including DOP, DIDP, DINP) incorporated and dispersed becomes. These titanium dioxide-added organic substances can then as starting material for the composite production can be used.

For dispersing the titanium dioxide in the masterbatch or in organic substances, it is possible to use customary dispersion methods, in particular using melt extruders, dissolvers, three-rollers, ball mills, bead mills, dip mills, ultrasound or kneaders. Particularly advantageous is the Use of dip mills or bead mills with pearl diameters d <1.5 mm.

The composite according to the invention has surprisingly outstanding mechanical and tribological properties. Compared to the unfilled Polymer have the composites of the invention significantly improved bending moduli, bending strengths, tensile moduli, Tensile strengths, fracture toughness, Fracture toughness, impact strength and wear rates.

• – Komposite, bestehend aus mindestens einem Thermoplast, mindestens einem Hochleistungskunststoff und/oder mindestens einem Epoxidharz und einem gefällten, oberflächenmodifiziertem Titandioxid, dessen Kristallitgröße d₅₀ kleiner 350 nm, bevorzugt kleiner 200 nm ist und besonders bevorzugt zwischen 3 und 50 nm beträgt und wobei das Titandioxid sowohl anorganisch und/oder organisch oberflächenmodifiziert sein kann (nachfolgend auch Titandioxid-Komposite genannt);
• – Titandioxid-Komposite, wobei als Thermoplast Polyester, Polyamid, PET, Polyethylen, Polypropylen, Polystyrol, dessen Copolymerisate und Elends, Polycarbonat, PMMA oder PVC eingesetzt wird;
• – Titandioxid-Komposite, wobei als Hochleistungskunststoff PTFE, Fluor-Thermoplaste (z. B. FEP, PFA, u.a.), PVDF, Polysulfone (z. B. PES, PSU, PPSU, u.a.), Polyetherimid, flüssigkristalline Polymere und Polyetherketone eingesetzt wird.
• – Titandioxid-Komposite, wobei als Duromer ein Epoxidharz eingesetzt wird;
• – Titandioxid-Komposite, wobei das Komposit 12 bis 99,8 Gew.-% Thermoplast, 0,1 bis 60 Gew.-% gefälltes, oberflächenmodifiziertes Titandioxid, 0 bis 80 Gew.-% mineralischen Füllstoff und/oder Glasfaser, 0,05 bis 10 Gew.-% Antioxidant, 0 bis 2,0 Gew.-% organischen Metalldesaktivator, 0 bis 2,0 Gew.-% Prozessadditive (u. a. Dispergierhilfen, Haftvermittler), 0 bis 10 Gew.-% Pigment, und 0 bis 40 Gew.-% Flammschutzmittel (z. B. Aluminiumhydroxid, Antimontrioxid, Magnesiumhydroxid, u. a.) enthält.
• – Titandioxid-Komposite, wobei das Komposit 12 bis 99,9 Gew-% Hochleistungskunststoff, 0,1 bis 60 Gew-% gefälltes, oberflächenmodifiziertes Titandioxid, 0 bis 80 Gew-% mineralischen Füllstoff und/oder Glasfaser, 0 bis 5,0 Gew-% Prozessadditive (u.a. Dispergierhilfen, Haftvermittler), 0 bis 10 Gew-% Pigment enthält.
• – Titandioxid-Komposite, wobei das Komposit 20 bis 99,9 Gew.-% Epoxidharz, 0,1 bis 60 Gew.-% gefälltes, oberflächenmodifiziertes Titandioxid, 0 bis 80 Gew.-% mineralischen Füllstoff und/oder Glasfaser, 0 bis 10 Gew.-% Prozessadditive, 0 bis 10 Gew.-% Pigment, und 0 bis 40 Gew.-% Aluminiumhydroxid enthält;
• – Titandioxid-Komposite, wobei der Anteil von gefälltem, oberflächenmodifiziertem Titandioxid im Komposit 0,1 bis 60 Gew.-%, bevorzugt 0,5 bis 30 Gew.-%, besonders bevorzugt 1,0 bis 20 Gew.-%, beträgt;
• – Titandioxid-Komposite, wobei das Titandioxid eine anorganische und/oder eine organische Oberflächenmodifizierung besitzt;
• – Titandioxid-Komposite, wobei die anorganische Oberflächenmodifizierung des ultrafeinen Titandioxids aus einer Verbindung besteht, die mindestens zwei der folgenden Elemente enthält: Aluminium-, Antimon-, Barium-, Calcium-, Cer-, Chlor-, Cobalt-, Eisen-, Phosphor-, Kohlenstoff-, Mangan-, Sauerstoff-, Schwefel-, Silicium-, Stickstoff-, Strontium-, Vanadium-, Zink-, Zinn- und/oder Zirkon-Verbindungen oder Salze;
• – Titandioxid-Komposite, wobei die organische Oberflächenmodifizierung aus einem oder mehreren der folgenden Bestandteile besteht: Silane, Siloxane, Polysiloxane, Polycarbonsäuren, Polyester, Polyether, Polyamide, Polyethylenglykole, Polyalkohole, Fettsäuren, bevorzugt ungesättigte Fettsäuren, Polyacrylate, organische Phosphonsäuren, Titanate, Zirkonate, Alkyl- und/oder Arylsulfonate, Alkyl- und/oder Arylsulfate, Alkyl- und/oder Arylphosphorsäureester;
• – Titandioxid-Komposite, wobei die Oberflächenmodifizierung eine oder mehrere der folgenden funktionellen Gruppen enthält: Hydroxyl-, Amino-, Carboxyl-, Epoxy-, Vinyl-, Methacrylat-, und/oder Isocyanat-Gruppen, Thiole, Alkylthiocarboxylate, Di- und/oder polysulfidische Gruppen;
• – Titandioxid-Komposite, wobei die Oberflächenmodifizierung kovalent an die Partikeloberfläche angebunden ist;
• – Titandioxid-Komposite, wobei die Oberflächenmodifizierung ionisch an die Partikeloberfläche gebunden ist;
• – Titandioxid-Komposite, wobei die Oberflächenmodifizierung über physikalische Wechselwirkungen an die Partikeloberfläche gebunden ist;
• – Titandioxid-Komposite, wobei die Oberflächenmodifizierung durch eine Dipol-Dipol- oder eine Van-der-Waals-Wechselwirkung an die Partikeloberfläche gebunden ist;
• – Titandioxid-Komposite, wobei die oberflächenmodifizierten Titandioxidpartikel eine Bindung zur polymeren Matrix eingehen;
• – Titandioxid-Komposite, wobei eine chemische Bindung zwischen den Titandioxidpartikeln und der polymeren Matrix vorliegt;
• – Titandioxid-Komposite, wobei die chemische Bindung zwischen den Titandioxidpartikeln und der polymeren Matrix eine kovalente und/oder eine ionische Bindung ist;
• – Titandioxid-Komposite, wobei eine physikalische Bindung zwischen den Titandioxidpartikeln und der polymeren Matrix vorliegt;
• – Titandioxid-Komposite, wobei die physikalische Bindung zwischen den Titandioxidpartikeln und der polymeren Matrix eine Dipol-Dipol-Bindung (Keeson), eine induzierte Dipol-Dipol-Bindung (Debye) oder eine dispersive Bindung (Van-der-Waals) ist;
• – Titandioxid-Komposite, wobei eine physikalische und eine chemische Bindung zwischen den Titandioxidpartikeln und der polymeren Matrix vorliegen;
• – Verfahren zur Herstellung der Titandioxid-Komposite;
• – Verfahren zur Herstellung der Titandioxid-Komposite, wobei zunächst ein Masterbatch hergestellt wird und das Titandioxid-Komposit durch Verdünnung des Masterbatches mit dem Rohpolymer erhalten wird, wobei das Masterbatch 5-80 Gew.-% Titandioxid, bevorzugt 15-60 Gew.-% Titandioxid enthält;
• – Verfahren zur Herstellung der Titandioxid-Komposite, bei dem das Titandioxid enthaltende Masterbatch mit dem Rohpolymer verdünnt wird und sich vorzugsweise eine Dispergierung anschließt;
• – Verfahren zur Herstellung der Titandioxid-Komposite, bei dem das Masterbatch mit den weiteren Bestandteile der Rezeptur in einem oder mehreren Schritten vermischt wird und sich vorzugsweise noch eine Dispergierung anschließt;
• – Verfahren zur Herstellung der Titandioxid-Komposite, wobei das Titandioxid zunächst in organischen Substanzen insbesondere in Polyolen, Polyglycolen, Polyethern, Dicarbonsäuren und deren Derivate, AH-Salz, Caprolactam, Paraffinen, Phosphorsäureestern, Hydroxycarbonsäureestern, Cellulose, Styrol, Methylmethacrylat, organische Diamiden, Epoxidharzen und Weichmachern (u.a. DOP, DIDP, DINP) eingearbeitet und dispergiert wird;
• – Verfahren zur Herstellung der Titandioxid-Komposite, wobei die mit Titandioxid versetzten organischen Substanzen als Ausgangsmaterial für die Komposit-Herstellung genutzt werden;
• – Verfahren zur Herstellung der Titandioxid-Komposite, wobei die Dispergierung des Titandioxids im Masterbatch bzw. in den organischen Substanzen mittels üblicher Dispergierverfahren, insbesondere unter Verwendung von Schmelzextrudern, Dissolvern, Dreiwalzen, Kugelmühlen, Perlmühlen, Tauchmühlen, Ultraschall oder Knetern durchgeführt wird;
• – Verfahren zur Herstellung der Titandioxid-Komposite, wobei für die Dispergierung des Titandioxids vorzugsweise Tauchmühlen oder Perlmühlen verwendet werden;
• – Verfahren zur Herstellung der Titandioxid-Komposite, wobei für die Dispergierung des Titandioxids vorzugsweise Perlmühlen verwendet werden, wobei die Perlen vorzugsweise Durchmesser von d < 1,5 mm, besonders vorzugsweise von d < 1,0 mm, ganz besonders vorzugsweise von d < 0,3 mm besitzen;
• – Titandioxid-Komposite, die verbesserte mechanische Eigenschaften und verbesserte tribologische Eigenschaften besitzen;
• – Titandioxid-Komposite, bei denen gleichzeitig die Festigkeit und die Zähigkeit durch den Einsatz der oberflächenmodifizierten Titandioxidpartikel verbessert werden;
• – Titandioxid-Komposite, bei denen die Verbesserung der Festigkeit und Zähigkeit in einem Biegeversuch oder einem Zugversuch beobachtet werden können;
• – Titandioxid-Komposite, die verbesserte Schlagzähigkeiten und/oder verbesserte Kerbschlagzähigkeiten besitzen;
• – Titandioxid-Komposite, bei denen die Verschleißfestigkeit durch den Einsatz der oberflächenmodifizierten Titandioxidpartikel verbessert wird;
• – Titandioxid-Komposite, bei denen die Kratzfestigkeit durch den Einsatz der oberflächenmodifizierten Titandioxidpartikel verbessert wird;
• – Titandioxid-Komposite, bei denen die Spannungsrissbeständigkeit durch den Einsatz der oberflächenmodifizierten Titandioxidpartikel verbessert wird;
• – Titandioxid-Komposite, bei denen eine Verbesserung der Kriechbeständigkeit beobachtet werden kann;
• – Verwendung der Titandioxid-Komposite als Ausgangsmaterial für die Herstellung von Formkörpern, Halbzeugen, Folien oder Fasern, insbesondere für die Herstellung von Spritzgussteilen, Blasformen oder Fasern;
• – Verwendung der Titandioxid-Komposite in Form von Fasern, die sich vorzugsweise durch verbesserte Reißfestigkeiten auszeichnen;
• – Verwendung der Titandioxid-Komposite für Bauteile für den Automobil-, Luftfahrt- oder den Raumfahrt-Bereich, insbesondere in Form von Gleitlagern, Zahnrädern, Walzen- oder Kolbenbeschichtungen
• – Verwendung der Titandioxid-Komposite beispielsweise zur Herstellung von Bauteilen im Gussverfahren, als Klebstoff, als Industriefußboden, als Betonbeschichtung, als Betonreparatur, als Korrosionsschutzbeschichtung, zum Vergießen von elektrischen Bauteilen oder anderen Objekten, zur Sanierung von Metallrohren, als Trägermaterial in der Kunst oder zum Abdichten von Holzterrarien.

The invention in detail:

• - Composites, consisting of at least one thermoplastic, at least one high performance plastic and / or at least one epoxy resin and a precipitated, surface-modified titanium dioxide whose crystallite size d _{50 is} less than 350 nm, preferably less than 200 nm and more preferably between 3 and 50 nm and wherein the Titanium dioxide may be both inorganic and / or organic surface-modified (hereinafter also titania composites called);
• - Titanium dioxide composites, being used as a thermoplastic polyester, polyamide, PET, polyethylene, polypropylene, polystyrene, its copolymers and blends, polycarbonate, PMMA or PVC;
• Titanium dioxide composites, in which high performance plastics include PTFE, fluoroplastics (eg FEP, PFA, etc.), PVDF, polysulfones (eg PES, PSU, PPSU, etc.), polyetherimide, liquid crystalline polymers and polyether ketones ,
• - Titanium dioxide composites, wherein as an elastomer an epoxy resin is used;
• Titanium dioxide composites, wherein the composite 12 to 99.8 wt .-% thermoplastic, 0.1 to 60 wt .-% precipitated, surface-modified titanium dioxide, 0 to 80 wt .-% mineral filler and / or glass fiber, 0.05 to 10% by weight of antioxidant, 0 to 2.0% by weight of organic metal deactivator, 0 to 2.0% by weight of process additives (inter alia dispersing aids, adhesion promoters), 0 to 10% by weight of pigment, and 0 to 40 Wt .-% flame retardant (eg., Aluminum hydroxide, antimony trioxide, magnesium hydroxide, etc.) contains.
• Titanium dioxide composites, wherein the composite 12 to 99.9 wt% high performance plastic, 0.1 to 60 wt% precipitated, surface-modified titanium dioxide, 0 to 80 wt% mineral filler and / or glass fiber, 0 to 5.0 wt -% process additives (including dispersing aids, adhesion promoters), 0 to 10% by weight of pigment.
• Titanium dioxide composites, wherein the composite 20 to 99.9 wt .-% epoxy resin, 0.1 to 60 wt .-% precipitated, surface-modified titanium dioxide, 0 to 80 wt .-% mineral filler and / or glass fiber, 0 to 10 Wt% process additives, 0 to 10 wt% pigment, and 0 to 40 wt% aluminum hydroxide;
• Titanium dioxide composites, wherein the proportion of precipitated, surface-modified titanium dioxide in the composite 0.1 to 60 wt .-%, preferably 0.5 to 30 wt .-%, particularly preferably 1.0 to 20 wt .-%, is;
• Titanium dioxide composites, wherein the titanium dioxide has an inorganic and / or an organic surface modification;
• Titanium dioxide composites, wherein the inorganic surface modification of the ultrafine titanium dioxide consists of a compound containing at least two of the following elements: aluminum, antimony, barium, calcium, cerium, chlorine, cobalt, iron, phosphorus , Carbon, manganese, oxygen, sulfur, silicon, nitrogen, strontium, vanadium, zinc, tin and / or zirconium compounds or salts;
• Titanium dioxide composites, wherein the organic surface modification consists of one or more of the following constituents: silanes, siloxanes, polysiloxanes, polycarboxylic acids, polyesters, polyethers, polyamides, polyethylene glycols, polyalcohols, fatty acids, preferably unsaturated fatty acids, polyacrylates, organic phosphonic acids, titanates, zirconates , Alkyl and / or aryl sulfonates, alkyl and / or aryl sulfates, alkyl and / or aryl phosphoric acid esters;
• Titanium dioxide composites, the surface modification containing one or more of the following functional groups: hydroxyl, amino, carboxyl, epoxy, vinyl, methacrylate, and / or isocyanate groups, thiols, alkylthiocarboxylates, di- and / or or polysulfidic groups;
• - Titanium dioxide composites, wherein the surface modification is covalently attached to the particle surface;
• - Titanium dioxide composites, wherein the surface modification is ionically bonded to the particle surface;
• - Titanium dioxide composites, wherein the surface modification is bound to the particle surface via physical interactions;
• Titanium dioxide composites, wherein the surface modification is bound to the particle surface by a dipole-dipole or van der Waals interaction;
• - Titanium dioxide composites, wherein the surface-modified titanium dioxide particles form a bond to the polymeric matrix;
• - Titanium dioxide composites, wherein a chemical bond between the titanium dioxide particles and the polymeric matrix is present;
• - Titanium dioxide composites, wherein the chemical bond between the titanium dioxide particles and the polyme a matrix is a covalent and / or an ionic bond;
• Titanium dioxide composites, wherein there is a physical bond between the titanium dioxide particles and the polymeric matrix;
• Titanium dioxide composites, wherein the physical bond between the titanium dioxide particles and the polymeric matrix is a dipole-dipole bond (Keeson), an induced dipole-dipole bond (Debye) or a dispersive bond (Van der Waals);
• Titanium dioxide composites wherein there is a physical and a chemical bond between the titanium dioxide particles and the polymeric matrix;
• - Process for the preparation of titanium dioxide composites;
• A process for the preparation of the titanium dioxide composites, wherein firstly a masterbatch is produced and the titanium dioxide composite is obtained by diluting the masterbatch with the crude polymer, the masterbatch containing 5-80% by weight of titanium dioxide, preferably 15-60% by weight Contains titanium dioxide;
• - Process for the preparation of titanium dioxide composites, wherein the titanium dioxide-containing masterbatch is diluted with the crude polymer and preferably followed by a dispersion;
• - Process for the preparation of titanium dioxide composites, in which the masterbatch is mixed with the other constituents of the formulation in one or more steps and preferably still followed by a dispersion;
• - Process for the preparation of titanium dioxide composites, wherein the titanium dioxide first in organic substances, especially in polyols, polyglycols, polyethers, dicarboxylic acids and their derivatives, AH salt, caprolactam, paraffins, phosphoric esters, hydroxycarboxylic, cellulose, styrene, methyl methacrylate, organic diamides, Epoxy resins and plasticizers (including DOP, DIDP, DINP) is incorporated and dispersed;
• - Process for the preparation of titanium dioxide composites, wherein the titanium dioxide added organic substances are used as starting material for the composite production;
• - Process for the preparation of titanium dioxide composites, wherein the dispersion of the titanium dioxide in the masterbatch or in the organic substances by conventional dispersing method, in particular using melt extruders, dissolvers, three rollers, ball mills, bead mills, dip mills, ultrasound or kneaders is performed;
• - Process for the preparation of titanium dioxide composites, wherein for the dispersion of titanium dioxide preferably dip mills or bead mills are used;
• - Process for the preparation of titanium dioxide composites, preferably bead mills are used for the dispersion of titanium dioxide, wherein the beads preferably diameter of d <1.5 mm, particularly preferably d <1.0 mm, most preferably of d <0 , 3 mm own;
• Titanium dioxide composites possessing improved mechanical properties and improved tribological properties;
• Titanium dioxide composites, which at the same time improve the strength and toughness through the use of the surface-modified titanium dioxide particles;
• Titanium dioxide composites for which the improvement in strength and toughness can be observed in a bending test or a tensile test;
• Titanium dioxide composites having improved impact strengths and / or improved notched impact strengths;
• - Titanium dioxide composites, in which the wear resistance is improved by the use of surface-modified titanium dioxide particles;
• - Titanium dioxide composites, in which the scratch resistance is improved by the use of the surface-modified titanium dioxide particles;
• - Titanium dioxide composites, in which the stress cracking resistance is improved by the use of the surface-modified titanium dioxide particles;
• Titanium dioxide composites for which an improvement in creep resistance can be observed;
• - Use of titanium dioxide composites as starting material for the production of moldings, semi-finished products, films or fibers, in particular for the production of injection molded parts, blow molding or fibers;
• Use of the titanium dioxide composites in the form of fibers, which are preferably distinguished by improved tear strengths;
• - Use of titanium dioxide composites for components for the automotive, aerospace or space sector, in particular in the form of plain bearings, gears, roller or piston coatings
• Use of titanium dioxide composites, for example, for the production of components in the casting process, as an adhesive, industrial flooring, concrete coating, concrete repair, as corrosion protection coating, for casting of electrical components or other objects, for the renovation of metal pipes, as a support material in the art or Sealing of wood terrariums.

The Invention is illustrated by the following examples, without to restrict it to it.

Preparation of inorganic surface-modified Titanium dioxide:

3.7 kg of a 6.5% strength by weight aqueous suspension of ultrafine titanium dioxide particles having average primary particle diameters d ₅₀ of 14 nm (result of TEM investigations) are heated to a temperature of 40 ° C. with stirring. With 10% sodium hydroxide solution, the pH of the suspension is adjusted to 12. 14.7 ml of an aqueous sodium silicate solution (284 g of SiO ₂ / L), 51.9 ml of an aluminum sulfate solution (containing 75 g of Al ₂ O ₃ / L) and 9.7 ml of a sodium aluminate solution ( 275 g of Al ₂ O ₃ / L) while maintaining the pH of 12.0 added to the suspension. The suspension is homogenized for a further 10 minutes with vigorous stirring. Subsequently, the pH is adjusted slowly, preferably within 60 minutes, by adding a 5% sulfuric acid to a pH of 7.5. This is followed by a maturing time of 10 minutes at a temperature of 40 ° C. The suspension is then washed to a conductivity of less than 100 μS / cm and then spray-dried.

example 1

The starting material used is a precipitated, surface-modified titanium dioxide having a crystallite size d ₅₀ of 14 nm. The titanium dioxide surface is inorganic and organically surface-modified. The inorganic surface modification consists of an aluminum-oxygen compound. The organic surface modification consists of a polyalcohol. The polyalcohol enters into a physical interaction with the surface of the titanium dioxide. In a polyamide, the remaining OH groups of the polyhydric alcohol with the carbonyl radicals (-C = O) of the polyamide can undergo a dipole-dipole interaction.

First, a 15 vol .-% composite of the described titanium dioxide in polyamide 66 is prepared by extrusion. From this material test specimens for testing the flexural strength (according to DIN EN ISO 178), the tensile strength (according to DIN EN ISO 527), the impact strength (according to ASTM E399-90) and the creep strain (according to DIN EN ISO 899-1) are manufactured. The results of the test are shown in Tables 1 and 2. The use of the surface-modified titanium dioxide has markedly improved flexural strength, flexural modulus, impact strength, tensile strength and creep strain compared to unfilled polyamide 66. Table 1: Results of the 3-point bending test of the composite from Example 1 in comparison to the unfilled polyamide 66 (PA 66) sample Bending strength [MPa] Flexural modulus [MPa] PA66 40 950 PA66 + 15 vol.% Surface-modified titanium dioxide 55 1420 TABLE 2 Tensile strength, impact resistance and creep strain of the composite from Example 1 in comparison to unfilled polyamide 66 (PA 66) sample Tensile strength [MPa] Impact strength [kJ / m ² ] Creep strain [%] PA66 33 2.1 1.4 PA66 + 15 vol.% Surface-modified titanium dioxide 46 3.5 0.9

Example 2

The 15 vol.% Composite from Example 1 was diluted by extrusion to particle contents of 0.5-7.0 vol.%. From these composites and the 15 vol.% Composite specimens were prepared for Charpy impact strength testing (DIN EN ISO 179). The results of the test of Impact impact are in the 1 applied. The notched impact strength of the composites is significantly increased compared to the unfilled polyamide 66. Surprisingly, very low particle contents of 0.5-2.0 vol.% Lead to the highest notched impact strengths.

Example 3

The starting material used is a precipitated, surface-modified titanium dioxide having a crystallite size d ₅₀ of 14 nm. The titanium dioxide surface is inorganic and organically surface-modified. The inorganic surface modification consists of an aluminum-oxygen compound. The organic surface modification consists of a polyalcohol. The polyalcohol enters into a physical interaction with the surface of the titanium dioxide.

When polymeric matrix is the commercially available Epilox A epoxy resin 19-03 Fa. Leuna resins GmbH used. The hardener is the amine hardener HY 2954 of the company Vantico GmbH & Co KG used.

First, will the powdery one Titanium dioxide in the liquid Epoxy resin with dissolver dispersion with a content of 14 Vol .-% incorporated. After this predispersion, the mixture becomes with a dip mill Dispersed for 90 minutes at a speed of 2500 rev / min. As pearls 1 mm zirconia beads are used. This approach comes with mixed with the pure resin so that composites are formed after the addition of the hardener, containing 2 vol .-% and 10 vol .-% titanium dioxide. The curing of the Composite takes place in the drying cabinet.

Example 4

For the mechanical tests of the composite from Example 3 described below, test specimens with defined dimensions are produced. The mechanical characterization is carried out in a three-point bending test according to DIN EN ISO 178 on the basis of specimens, which were machined from cast plates with a precision saw. At least five samples of dimensions 80 × 10 × 4 mm ³ are tested at a test speed of 2 mm / min at room temperature.

The fracture toughness K _IC (according to ASTM E399-90) is determined at a test speed of 0.1 mm / min using Compact Tension (CT) specimens. In the CT samples, a sharp tear was produced by the controlled impact of a razor blade. This results in the crack tip of the required for determining the critical stress intensity factor level strain state.

The results of the bending tests and the fracture toughness test are shown in Table 3. The composites of the invention show greatly improved properties compared to the pure resin. The flexural strength could be improved by 11%, the flexural modulus even by 45% compared to the unfilled pure resin. The fracture toughness was increased by about 40%. Table 3: Results of the bending test and the fracture toughness test of the composites of Examples 3 and 4, respectively Flexural modulus [MPa] Bending strength [MPa] Fracture toughness [MPa m ^½ ] 2800 132 0.63 2900 134 0.80 4100 148 0.88

Example 5

Δm:

Gewichtsabnahme

ρ:

Dichte

v:

Rotationsgeschwindigkeit des Gegenkörpers

t:

Laufzeit

F_N:

Normalkraft

From the composite of Example 3, specimens (pins) of dimensions 4 × 4 × 20 mm ^{3 are} sawn. These test specimens are tested with the aid of the model test arrangement "Block and Ring" ( 2 ), by means of which abrasion wear tests can be carried out, are characterized in a tribological way. In the abrasion test, ground needle roller bearings of steel 100Cr6 with a diameter of 60 mm serve as a counter-body, the surface of which was modified by glued-on corundum paper of the 240 grit to increase the roughness. Before starting the experiment, the steel rings are cleaned with acetone to remove any troublesome oil or dirt residue. The specimens were also cleaned and their initial mass m _{A determined} with the precision balance. To carry out the wear tests, the samples with a constant Flä Pressing p pressed against the corresponding contact surface of the counter body, which rotates at a constant speed. A weight with a defined mass generates the desired contact pressure or the normal force F _N via a lever arm. All experiments are carried out at room temperature and a test duration of 30 seconds, wherein the surface pressure p is systematically varied. For statistical reasons, four samples of each material are tested. After the end of the experiment, the wear-related weight loss Δm of the samples is determined. From this, the specific wear rate w _{s was} calculated according to the following formula:

Dm:

loss in weight

ρ:

density

v:

Rotational speed of the counter body

t:

running time

F _N :

normal force

3 shows the measured wear rate as a function of the contact pressure. Regardless of the contact pressure, the wear rate of the composites according to the invention (Epilox A19-03 / TiO ₂ 2 vol.% And Epilox A19-03 / TiO ₂ 10 vol.%) Is significantly lower than the wear rate of the pure resin. Overall, an improvement of up to 40% can be achieved.

Example 6

The starting material used is a precipitated, surface-modified titanium dioxide having a crystallite size d ₅₀ of 14 nm. The titanium dioxide surface is inorganic and organically surface-modified. The inorganic surface modification consists of an aluminum-oxygen compound. The organic surface modification consists of an epoxysilane, which can form covalent bonds to the polymeric matrix.

When polymeric matrix is the commercially available Epilox A epoxy resin 19-03 Fa. Leuna resins GmbH used. The hardener is the amine hardener HY 2954 of the company Vantico GmbH & Co KG used.

First, will the powdery one Titanium dioxide in the liquid Epoxy resin with dissolver dispersion with a content of 14 Vol .-% incorporated. After this predispersion, the mixture becomes with a dip mill Dispersed for 90 minutes at a speed of 2500 rev / min. As pearls 1 mm zirconia beads are used. This approach comes with mixed with the pure resin so that composites are formed after the addition of the hardener, containing 2 vol .-% and 10 vol .-% titanium dioxide. The curing of the Composite takes place in the drying cabinet.

Example 7

For the following described mechanical tests of the composite from Example 6 are test specimens with defined dimensions produced. The test specimen production and the mechanical tests on the specimens are analogous to the example 4 instead.

The results of the bending tests and the fracture toughness test are shown in Table 4. The composites of the invention show greatly improved properties compared to the pure resin. Table 4: Results of the bending test and the fracture toughness test sample Flexural modulus [MPa] Bending strength [MPa] Fracture toughness [MPa m ^1/2 ] Notched impact strength [kJ / m ² ] Pure resin (Epilox A 19-03) 2380 69 0.63 0.9 Reinharz +1 Vol .-% surface-modified titanium dioxide with dipole-dipole interactions 3000 64 0.83 nb Pure resin + 2% by volume surface-modified titanium dioxide with crosslinking groups 2390 84 0.78 1.2 Pure resin + 10% by volume surface-modified titanium dioxide with crosslinking groups 3600 85 1.42 1.6

Claims (25)

Composite of fillers and pigments in a polymeric matrix, characterized in that it contains titanium dioxide, at least one thermoplastic, a high performance plastic and / or an epoxy resin, wherein the crystallite size of the titanium dioxide d _{50 is} less than 350 nm, preferably less than 200 nm and more preferably between 3 and 50 nm and the titanium dioxide may be both inorganic and / or organic surface-modified. Composite according to claim 1, characterized in that as thermoplastic at least one polyester, a Polyamide, a PET, a polyethylene, a polypropylene, a polystyrene, its copolymers and / or blends, a polycarbonate, a PMMA and / or a polyvinyl chloride or that as a thermoplastic mixtures be selected from at least two of these thermoplastics. Composite according to claim 1 or 2, characterized in that as a high-performance plastic at least one PTFE, a fluoroplastic (eg FEP, PFA, etc.), PVDF, a polysulfone (eg PES, PSU, PPSU, etc.), a polyetherimide, a liquid crystalline Polymer and / or a polyether ketone or as a high performance plastic Mixtures of at least two of these high performance plastics are selected. Composite according to a or more of the claims 1 to 3, characterized in that the composite 12 to 99.8 wt .-% Thermoplastic, 0.1 to 60 wt .-% titanium dioxide, 0 to 80 wt .-% mineral Filler and / or Glass fiber, 0.05 to 10% by weight of antioxidant, 0 to 2.0% by weight of organic Metal deactivator, 0 to 2.0% by weight of process additives (inter alia dispersing aids, Adhesion promoter, u. a.), 0 to 10 wt .-% pigment, and 0 to 40 wt .-% Flame retardants (eg aluminum hydroxide, antimony trioxide, magnesium hydroxide, u. a.) contains. Composite according to a or more of the claims 1 to 4, characterized in that the composite 12 to 99.9% by weight High performance plastic, 0.1 to 60 wt% titanium dioxide, 0 to 80 % By weight mineral filler and / or glass fiber, 0 to 5.0% by weight of process additives (inter alia dispersing aids, Adhesion promoter), 0 to 10% by weight of pigment. Composite according to one or more of Claims 1 to 5, characterized in that the composite contains 20 to 99.9% by weight of epoxy resin, 0.1 to 60% by weight of titanium dioxide, 0 to 80% by weight of mineral filler and / or or glass fiber, 0 to 10% by weight of process additives, 0 to 10% by weight of pigment, and 0 to 40% by weight of alumi contains niumhydroxid. Composite according to a or more of the claims 1 to 6, characterized in that the proportion of titanium dioxide in the Composite 0.1 to 60 wt .-%, preferably 0.5 to 30 wt .-%, especially preferably 1.0 to 20 wt .-%, is. Composite according to a or more of the claims 1 to 7, characterized in that the titanium dioxide with at least an inorganic and / or organic compound surface-modified is. Composite according to claim 8, characterized in that the weight fraction of the inorganic compounds based on titanium dioxide 0.1 to 50.0 wt .-%, preferably 1.0 to 10.0 Wt .-% is. Composite according to claim 8 or 9, characterized in that the inorganic compounds are selected from water-soluble Aluminum, antimony, barium, calcium, cerium, chlorine, cobalt, Iron, phosphorus, carbon, manganese, oxygen, sulfur, Silicon, nitrogen, strontium, vanadium, zinc, tin and / or Zirconium compounds or salts. Composite according to a or more of the claims 8 to 10, characterized in that the organic compounds selected are from one or more of the following compounds: silanes, Siloxanes, polysiloxanes, polycarboxylic acids, polyesters, polyethers, Polyamides, polyethylene glycols, polyalcohols, fatty acids, preferred unsaturated fatty acids, Polyacrylates, organic phosphonic acids, titanates, zirconates, Alkyl and / or arylsulfonates, alkyl and / or aryl sulfates, alkyl and / or aryl phosphoric acid esters. Composite according to a or more of the claims 8 to 10, characterized in that the surface modification contains one or more of the following functional groups: hydroxyl, Amino, carboxyl, epoxy, vinyl, methacrylate, and / or isocyanate groups, Thiols, alkyl thiocarboxylates, di- and / or polysulfidic groups. Composite according to a or more of the claims 8 to 12, characterized in that the surface-modified Titanium dioxide particles form a bond to the polymeric matrix. Composite according to one or more of claims 1 to 13, characterized in that the titanium dioxide particles have a primary particle size d ₅₀ of less than or equal to 0.1 microns, preferably from 0.05 to 0.005 microns. Process for the preparation of a composite according to or more of the claims 1 to 14, characterized in that from the titanium dioxide and a Part of the raw polymer is a masterbatch and the composite by dilution of the masterbatch with the crude polymer under dispersion becomes. Method according to claim 15, characterized in that from the titanium dioxide and a part the raw polymer is a masterbatch and the composite by dilution of the masterbatch with the crude polymer, the masterbatch 5-80 wt .-% titanium dioxide, preferably 15-60 wt .-% titanium dioxide. Method according to claim 15 or 16, characterized in that the masterbatch with the other ingredients of the recipe in one or more steps is mixed and preferably followed by a dispersion. Method according to one or more of the claims 15 to 17, characterized in that the titanium dioxide is initially in organic substances, especially in amines, polyols, styrenes, Formaldehydes and its molding compounds, vinyl ester resins, polyester resins or silicone resins are incorporated and dispersed. Method according to claim 18, characterized in that the offset with the titanium dioxide organic substances as starting material for the composite production be used. Process according to one or more of Claims 15 to 19, characterized in that the dispersion of the titanium dioxide in the masterbatch or in an organic substance is carried out by means of customary dispersing methods, in particular using melt extruders, dissolvers, three-rollers, ball mills, Perlmühlen, dip mills, ultrasonic or kneading is performed. Method according to one or more of the claims 15 to 20, characterized in that the dispersion of titanium dioxide preferably in dip mills or bead mills carried out becomes. Method according to one or more of the claims 15 to 21, characterized in that the dispersion of titanium dioxide in pearl mills carried out is, with pearls with diameters of d <1.5 mm, more preferably d <1.0 mm, very particular preferably of d <0.3 mm are used. Use of a composite according to one or more of claims 1 to 14 as starting material for the production of moldings, Semi-finished products, films or fibers, in particular for the production of injection-molded parts, Blow molding or fibers. Use of a composite according to one or more of claims 1 to 14 for Components for the automotive, aerospace or space sector, in particular in the form of plain bearings, gears, Roll or piston coatings. Use of a composite according to one or more of claims 1 to 14 for the production of components by casting, as an adhesive, as industrial floor, as a concrete coating, as a concrete repair, as a corrosion protection coating, for casting of electrical components or other objects, for renovation of metal tubes, as a carrier material in the art or for the sealing of wood terrariums.