Method for producing nanocomposite additives with improved delamination in polymers

The invention relates to a method for modification, in particular for the surface modification of an organophilic clay material, a modified organophilic clay material as can be obtained with the method according to the invention, a polymer composition which contains the modified organophilic clay material, the use of the modified organophilic clay material, pre-exfoliated nanocomposite. Additives, as well as a nanocomposite composition.

The properties of plastics or generally polymeric materials can be improved by adding nanocomposite additives. These allow the mechanical properties or gas permeation to be modified. Furthermore, the flame retardant properties can be improved, for example, by adding nanocomposite additives. A stable crust layer forms during the combustion of the polymer, which suppresses further ignition of the polymer.

Nanocomposite additives consist of natural or synthetic layered silicates, the surfaces of which are modified by organic molecules. The organic modification results in an adaptation of the surface polarity of the nanocomposite additives to the polarity of the polymers into which the nanocomposite additives are incorporated.

Nanocomposite additives are produced, for example, by dispersing and delaminating a swellable layered silicate, such as montmorillonite or hectorite, in water. The organic modification takes place, for example, by adding quaternary ammonium compounds which are bound to the negatively charged surface layers of the silicate lamellae by cation exchange. The polarity of the organically modified layered silicate can be influenced by the polarity of the organic component and can thus be matched to the polarity of the plastics used. There are two ways to incorporate the nanocomposite additives into polymers:<ul id="ul0001" list-style="none" compact="compact"><li>a) in-situ polymerization In the in-situ polymerization, the nanocomposite additive is dispersed in a monomer, with delamination of the layers of the layered silicate occurring. The monomer can also penetrate into the space between adjacent silicate layers and cause a layer expansion there. During the subsequent polymerization, the monomers which have penetrated into the interspaces also polymerize, as a result of which the silicate layers are separated from one another. In a subsequent dispersion step, the layers are largely delaminated. In order to achieve as complete a delamination as possible, the surface properties of the nanocomposite additive must be compatible with both the monomer and the polymer being formed.</li><li>b) Melt compounding During melt compounding, the powdery nanocomposite additive is dispersed in the polymer melt in an extruder. If the surface properties of the nanocomposite additive are sufficiently compatible with the polymer, the organically modified layered silicate lamellae will be delaminated during the extrusion process.</li></ul>

Delamination of the nanocomposite additive as completely as possible is a prerequisite for achieving the desired improvements in mechanical properties, gas permeation and flame retardancy in the plastic.

The nanocomposite additives used hitherto as additives for plastics consist of a layered silicate which is modified with a cationic organic component and, if appropriate, further components which influence the polarity of the layered silicate. For the production of the nanocomposite additives, the layered silicate is first dispersed in water and then the cationic organic component is added at a temperature of approx. 80 ° C. After addition of the cationic organic component, the modified layered silicate is precipitated, which is then separated off by filtration, dried and ground. A method for producing organically modified bentonites is described in US Pat. No. 4,695,402. Here, a slurry of the layered silicate is first stirred under high shear conditions and then an organic cation is added in an amount which corresponds to approximately 90 to 150% of the cation exchange capacity of the layered silicate. The organically modified layered silicate is separated from the slurry and then dried under gentle conditions below approximately 50 ° C. For example, ammonium, phosphonium or sulfonium compounds which carry long-chain linear or branched alkyl chains can be used as organic cations.

In US 5,429,999 an organically modified layered silicate is produced by first slurrying a layered silicate, for example montmorillonite, bentonite or hectorite, in water. The slurry is warmed to temperatures of about 70 ° C and then two different organic cations are added sequentially. Quaternary ammonium salts, phosphonium salts, sulfonium salts and mixtures thereof can be used, for example, as organic cations. The amount of the first organic cation added to the slurry corresponds to approximately 75 to 150% of the cation exchange capacity of the layered silicate. The amount of the second organic cation corresponds to approximately 0.01 to 20% by weight, based on the total amount of the organic cation. Then one or more organic anions are added which can react with the first and / or second organic cation to form a complex with the layered silicate. The first organic cation contains hydrophobic groups, while the second organic cation contains hydrophilic groups. The reaction product is then separated by filtration and dried under mild conditions.

EP 0 627 480 A1 describes an organically modified layered silicate which is obtained by first preparing an aqueous slurry of a layered silicate. The slurry is heated to temperatures of about 70 ° C and then an organic cation is added. The organophilic layered silicate can further contain an organic anion, such as sodium stearate. Both the organic cation and the organic anion are added to the aqueous slurry of the layered silicate. The reaction product is separated by filtration and then dried under mild conditions.

No. 4,874,728 describes an organophilic layered silicate which is obtained by first adding a quaternary ammonium salt which carries long-chain alkyl groups to an aqueous slurry of a layered silicate. The reaction product is then separated off by filtration and dried.

US 4,866,018 describes an organophilic layered silicate which is obtained by adding a quaternary ammonium compound to an aqueous slurry of a layered silicate, followed by the addition of an organic zirconium-aluminum complex. The reaction product is then separated off by filtration and dried.

The production of organophilic bentonites in the form of a dry mixing process bypassing the predispersion of sodium bentonite in water is described, for example, in US Pat. No. 4,474,706. An essentially dry, swellable clay is reacted with an organic ammonium compound without the addition of water. The clay and the ammonium compound are mixed at temperatures above the melting point of the ammonium compound. The components are mixed together until all liquid has been removed from the reaction mixture and an organically modified clay is obtained. The reaction of the ammonium compound with the clay can be determined by increasing the distance between adjacent layers of the clay. Mixtures of different ammonium compounds are preferably used for the modification. The ammonium salts can be added to the dry clay individually or as a mixture in any order. The temperature at which the components are mixed must be higher than the melting point of the highest melting quaternary ammonium compound. The modified clay can then be washed with water and then dried again and optionally ground. In order to achieve a reaction between clay and ammonium salt, intensive mixing of the components is necessary. In the case of implementation on a laboratory scale, this can be given, for example, by using a mortar and pestle. In the case of an implementation on an industrial scale, for example, a ribbon blender or an extruder can be used. During the mixing, a slight warming of the reaction mixture is observed, which is generated by compression and friction.

EP 0 905 204 A2 relates to surface-modified pigments based on platelet-shaped substrates with improved settling and stirring behavior, and to their production process and use. The production process is characterized in that platelet-shaped substrates with a layered silicate, preferably from the group of smectites, are dry-mixed in a mixing vessel.

WO 93/04118 A1 relates to a process for producing a polymeric nanocomposite comprising a continuous polymeric phase which is formed from a melt-processable polymer and platelet-shaped particles with an average thickness of 50 Å or less, and a polymeric nanocomposite obtainable by this process.

EP 0 554 776 A1 relates to novel flake-shaped pigments with an average particle size between 5 and 60 μm in the form of composite particles based on an ordered mixture, the composite particles being formed by a mixture consisting of a flake-shaped substrate and a pigment and / or a dye, as further defined in EP 0 554 776 A1, is stirred at high speed in the absence of a liquid medium.

DE 31 45 043 A1 describes a process for producing organophilic clays. A finely ground, dry raw clay is sprayed with a solution of an organic compound. The organic compound is, for example, a quaternary ammonium salt which is modified with long-chain organic groups. The sprayed clay is then dry compacted several times and then ground again to produce an organophilic clay. For the production of the organically modified clay, the clay sample in the examples is first introduced into a mixer and enough water is added to adjust the clay to a moisture content of 12% by weight. Then the required amount of the quaternary ammonium salt dissolved in water is added and the mixture is thoroughly mixed. After mixing, the sample is sent through a twin-roll plant, in which the reaction mixture is compressed under high pressure. The resulting compacted organophilic clay does not need to be dried further, but is merely crushed and sieved to the desired grain size.

WO 97/31873 describes a process for producing an organically modified clay which has been prepared by a dry process and which can be introduced directly as an additive in solvent. For this purpose, the clay is treated with a mixture of a quaternary ammonium salt and an aprotic polar solvent, which is selected from propylene carbonate, ethylene carbonate, N, N-dimethylformamide, N, N-dimethylacetamide and dimethyl sulfoxide. The reaction is usually carried out at room temperature or elevated temperatures, the reaction mixture being mixed until the polar aprotic solvent can react with the clay particles. For mixing, conventional mixers or extruders can be used which provide sufficient shear to cause the clay to react with the organic materials. After the reaction, the product obtained can optionally be dried and ground.

In order to be able to use the nanocomposite additives technically, they have to be exfoliated in the polymer. With this exfoliation, the original short-range order in the layered silicates is lost. The layered silicates are split up into individual platelets which only comprise individual silicate layers. Fully exfoliated smectites can form platelet-shaped particles with a very high aspect ratio of up to 1000. These particles correspond to platelets with a thickness in the range of approximately 1 nm, a width of approximately 100 nm and a length in the range of approximately 500 to 1,000 nm. Incorporation of the nanocomposite additives into a plastic matrix does increase the number of polymers of the layer spacing is observed, ie the polymer is partly embedded in spaces between adjacent lamellae of the layer silicate. However, there is no complete exfoliation of the nanocomposite additive in the polymer. Larger particles are present in the polymer, which are formed from agglomerates of the platelets described above. This has an adverse effect on the mechanical properties and the extrudability of the polymer compositions. It is also difficult to evenly distribute the nanocomposite additives evenly in the polymer composition.

The present invention was therefore based on the object of providing a process for the production of organically modified phyllosilicates which, when incorporated into plastics, show improved delamination, ie in which an almost complete exfoliation takes place during incorporation into a polymer mass.

This object is achieved with a method having the features of patent claim 1. Advantageous embodiments are the subject of the dependent claims.

The method according to the invention for modification, in particular for surface modification of an organophilic clay material, comprises the following steps:<ul id="ul0002" list-style="none" compact="compact"><li>a) providing a dry, powdery, organophilic clay material (component a);</li><li>b) providing at least one additive (component b) for modifying component a );</li><li>c) Intensive mixing of components a) and b) in a high shear mixing unit.</li></ul>wherein no water or solvent is added or is used for the addition of component b), and wherein the at least one additive (component b) is selected from: fatty acids, fatty acid derivatives, non-anionic organic components with at least one aliphatic or cyclic radical having 6 up to 32 carbon atoms and / or siloxane components. The method according to the invention is based on an organophilic clay material. Organophilic clay materials that can be used are, for example, organically modified nanocomposite additives, as are already known for use in polymer compositions. The inventive method of reacting the organophilic clay material with the additive, with intensive mixing of the organophilic clay material and additive in a high-shear mixing unit, results in a modified organophilic clay material which can be exfoliated significantly more easily and completely when incorporated into a polymer composition . The proportion of aggregates that are made up of several platelets can be significantly reduced. This can be seen, for example, on electron micrographs. The organophilic clay material can be produced in any way per se. The organophilic clay material is preferably produced by the general process described above, in which an aqueous suspension of a raw clay is first prepared and this is then reacted with an organic modification agent. Known methods, such as those described in the introduction, can be used here.

Conventional swellable layered silicates can be used as raw clays. These can be obtained from natural sources or synthetically produced. Smectites such as montmorillonite, hectorite, saponite and beidellite are particularly suitable. Bentonites can also be used. Because of the better swellability, the raw clays are preferably used in their sodium form.

All known modification agents per se can be used as the organic modification agent. Cationic organic agents, for example ammonium compounds, which carry at least one long-chain carbon chain which comprises, for example, 12 to 22 carbon atoms, are particularly suitable. The ammonium compound preferably comprises two longer-chain carbon chains. The carbon chains can be the same or different and linear or branched. Examples of suitable carbon chains are lauryl, stearyl, tridecyl, myristyl, pentadecyl and hexadecyl groups. Examples of branched longer-chain carbon chains are the 12-methylstearyl or the 12-ethylstearyl group. A particularly preferred carbon chain is the stearyl group. The further valences of the nitrogen atom are preferably saturated by shorter carbon chains, which can comprise 1 to 22 carbon atoms. The further valences of the nitrogen atom are particularly preferably saturated by methyl groups. However, it is also possible for the free valences to be saturated by hydrogen atoms. The carbon chains bonded to the nitrogen can be saturated or unsaturated and can also comprise aromatic groups, for example. For example, in addition to the long-chain carbon chains, the ammonium compound can also carry benzyl groups. The ammonium compounds can be used, for example, as chlorides. In addition to the ammonium compounds, for example the analog phosphonium and sulfonium compounds can also be used for the production of the organophilic clay material. Organophilic clays which are modified with ammonium compounds are particularly preferred as the starting material for the process according to the invention.

The organophilic clay material is modified with the help of an additive. The following compounds can be used as additives for modifying the organophilic clay material:

Fatty acids or fatty acid derivatives, which are preferably selected from fatty acids with 10-13 carbon atoms. Lauryl acid, palmitic acid, stearic acid, oleic acid, linoleic acid, caproic acid and castor oil should be mentioned here in particular.

The fatty acid derivatives include, for example, hydrogenated derivatives, alcohol derivatives, amine derivatives or mixtures thereof. They can also be selected from the group of polymeric fatty acids, keto fatty acids, fatty acid alkyloxazolines and fatty acid alkylbisoxazolines, or mixtures thereof. The unsaturated fatty acids include, in particular, the mono- or poly-unsaturated hydroxy fatty acids.

It is also possible to use non-anionic, organic components which have at least one aliphatic or cyclic radical having 6 to 32 carbon atoms, preferably 8 to 22 carbon atoms, in particular 10 to 18 carbon atoms. Such anionic, organic components of fatty acid derivatives from one of the following classes of substances are particularly preferred:<ol id="ol0001" compact="compact" ol-style=""><li>1. Fatty alcohols, saturated or unsaturated, including primary as well as secondary alcohols, especially with C₆ - C₂₂Remains;</li><li>2nd Fatty aldehydes, fatty ketones;</li><li>3rd Fatty alcohol polyglycol ether;</li><li>4th Fatty amines;</li><li>5. Mono-, di- and triglyceride esters;</li><li>6. Fatty acid alkanolamides;</li><li>7. Fatty acid amides;</li><li>8th. Fatty acid alkyl esters;</li><li>9. Fatty acid glucamides;</li><li>10th Dicarboxylic acid esters;</li><li>11. Waxes;</li><li>12th water-insoluble fatty acid soaps (this includes the salts of long-chain carboxylic acids with divalent metals;</li><li>13. Montan waxes (including waxes with a chain length of C₂₆ - C₃₂ to understand);</li><li>14. Paraffins and PE waxes.</li></ol>

Fatty alcohols, fatty amides, triglyceride esters, fatty acid alkyl esters and waxes are particularly preferred.

Furthermore, siloxane components can be used, which according to the IUPAC guideline means oligomers or polymeric siloxanes or siloxane derivatives. Siloxane derivatives are preferably those in which at least one of the CH₃Side groups on the Si atom is replaced by another functional group. Particularly preferred are, without limitation, oligoalkylsiloxanes, polydialkylarylsiloxanes, polydiarylsiloxanes, or a mixture thereof, the siloxane derivatives mentioned which have been functionalized with at least one reactive group being particularly preferred.

The mixing of organophilic clay and additive is carried out in the process according to the invention without the addition of water or another solvent. The organophilic clay material preferably has a very low moisture content or solvent content, so that no lump formation occurs during mixing or no plastic deformation can be carried out, as is required, for example, during extrusion. The organophilic clay material preferably has a moisture content or a solvent content of less than 10% by weight, in particular less than 5% by weight. The additive is added in bulk. If necessary, the additive can be melted before the addition.

The organophilic clay material is added to the high-shear mixing unit in the form of a powder. The organophilic clay material is ground to a small grain size. The average particle size (D₅₀Value) below 50 µm, preferably below a D₅₀-Value of 30 µm, especially less than 8 µm. The bulk density of the organophilic clay material is preferably less than 300 g / l, and is particularly preferably selected in the range from 150 to 250 g / l. The determination of the D₅₀-Values ​​and the bulk density is explained below in the experimental part of the description.

The organophilic clay and the additive are mixed in a high-shear mixing unit. A high-shear mixing unit is understood to mean a mixer in which the components of the mixture are mixed with one another under high shear action, without substantial compression or compaction taking place. During mixing, the mixture of organophilic clay material and additive thus remains in the form of a loose powder. After mixing, in contrast to the previously known modification processes, a powder is immediately obtained which can be incorporated, for example, into polymer compositions. It is therefore not necessary to grind the modified organophilic clay material again.

During the mixing process, the components are swirled intensively with a high energy input. At the same time, an increase in the temperature of the material to be mixed is observed during intensive mixing. At the beginning of the mixing process, the mixer consumes approximately the same amount of current. After the mixing process has progressed, the current consumption of the mixer increases and with it the energy input into the mixture. The powder begins to agglomerate. The bulk density of the powder also increases. The mixing process is preferably carried out in such a way that, due to the high energy input brought about by the intensive mixing, the mixture of organophilic clay material and additive is brought to a temperature within a few minutes, for example 6 to 8 minutes, at which the power consumption of the mixer is not increases linearly. The mixing process is only interrupted after an increased current consumption has been observed in the mixer for some time. When the optimal mixing time is exceeded, the current consumption increases significantly. This is a termination criterion for the mixing process.

It is assumed that the intensive mixing at elevated temperature constantly creates new surfaces on the organophilic clay material that come into contact with the additive. The surface of the organophilic clay material is coated with the additive. The additive is presumably partly incorporated into the spaces between adjacent lamellae. There is a change in the porosity of the organophilic clay material, as well as a change in the capillary forces. This significantly improves the delaminability of the modified organophilic clay material in polymers. In addition to the improved delamination, improved flowability of the modified organophilic clay material and improved meterability during the extrusion process are also observed.

The intensive mixing of organophilic clay material and additive is preferably carried out at elevated temperature. As already mentioned above, the high energy input that occurs during intensive mixing heats up the material to be mixed, a non-linear energy consumption of the mixer being observed after an initial mixing period.

The energy input into the mix preferably does not take place solely through the mixer, but the mix is ​​additionally heated. For this purpose, the mix is ​​evenly heated, for example with the help of a heat jacket. For example, a linear heat profile can be selected for heating. The heating is preferably continued until a non-linear increase in the energy consumption of the mixer indicates the conversion between organophilic clay material and additive.

The temperature up to which the mixed material formed from organophilic clay material and additive is heated is preferably chosen to be higher than the melting point of the at least one additive. If more than one additive is present in the mix, the temperature is selected so that it is above the melting point of the high-melting additive.

The temperature of the material to be mixed is preferably increased during intensive mixing. As already explained above, the temperature of the material to be mixed can first be increased with the aid of an additional supply of heat until the increased energy consumption of the mixer indicates a conversion between organophilic clay material and additive. Even after this point has been reached when mixing organophilic clay material and additive, the temperature is preferably increased further. The temperature can be raised by the energy input of the mixer or by an external supply of heat.

The intensive mixing of organophilic clay material and additive is preferably carried out in a temperature range from 20 to 200 ° C., in particular from 40 to 150 ° C.

As already explained, the bulk density of the organophilic clay material increases during the intensive mixing. In the case of intensive mixing, an increase in the bulk density of at least 20%, preferably at least 40%, in particular 60%, particularly preferably 80%, more preferably at least 100%, based on the bulk weight of the powdery, organophilic clay material is achieved.

The components of the mix, organophilic clay material and additive, are mixed together with high energy input. The energy input can be determined by the energy consumption of the mixer, that is to say the electrical power consumed during intensive mixing, which is then related to the volume of the material to be mixed. An energy input of at least 300 kW / m preferably takes place during intensive mixing³.

The intensive mixing is preferably carried out until an increase in the energy input, measured on the basis of the current consumption of the high-shear mixing unit, of at least 10%, preferably at least 20%, is achieved.

As already explained, a non-linear increase in the energy input of the mixing unit can be observed after an induction period. The intensive mixing is preferably continued until the increase in the energy input at the end of the intensive mixing according to claim 1 c), measured on the basis of the current consumption of the high-shear mixing unit, in the range between 10 and 50%, in particular between 20 and 30%, starting from the Current consumption of the high-shear agitator at the start of intensive mixing.

In particular, the intensive mixing is carried out at least until the power consumption of the mixing unit increases by at least 20% within one minute.

If the increase in current consumption described above is not achieved after a total period of intensive mixing of about 5 minutes, the high-shear mixing unit used is preferably additionally heated.

During the intensive mixing, the organophilic clay material used remains in the form of a powder. Due to the intensive swirling of the particles, the organophilic clay material is reacted with the additive and coated. The intensity of the mixing process and its duration is chosen so that the particle size, measured as D₅₀to increase by no more than 10% during intensive mixing. The particle size, measured as D, particularly preferably takes₅₀, not too or even falls. The change in particle size of the modified organophilic clay material relates to the original particle size, measured as D₅₀, component a) used for intensive mixing. The particle size D is preferably₅₀ of the modified organophilic clay material in the range of about 20 to 5 microns.

During the intensive mixing, the bulk weight of the organophilic clay material increases. Mixing is preferably stopped when the bulk density has increased by at most 200% compared to the initial bulk density of component a). The intensive mixing increases the bulk density to a maximum of three times the bulk weight of the untreated organophilic clay material. The bulk density of the modified organophilic clay material is preferably in the range from 400 to 550 g / l.

The additive is added in bulk to the organophilic clay material. According to one embodiment of the process according to the invention, both component a) and component b) are used in powder form. The powdery fine-grained solids behave like a liquid when mixed. A thrombus forms, so that the product is moved intensively in the horizontal and vertical directions. The intensive energy input leads to an increase in the temperature of the mixed material up to a non-linear increase in the current consumption of the mixer, resulting in an increase in the bulk density of the powder. However, additives that are liquid at room temperature can also be used. These are preferably added to the organophilic clay material in such a way that intensive mixing takes place immediately, so that the additive does not lead to a clumping of the organophilic clay material. The liquid additive is preferably given in the vicinity of a thrombus which forms when the organophilic clay material is swirled. The mixture of organophilic clay material and additive is agitated in the mixing unit in such a way that thrombus formation occurs at peripheral speeds of up to 200 m / s. During the mixing process, a cone formation is observed in the middle of the mixing vessel, ie the mix is ​​drawn to the bottom of the mixing unit in the form of a cone during the intensive mixing process.

In the method according to the invention, the organophilic clay material is in the form of a powder both before and after the modification. The modified organophilic clay material obtained is preferably further processed as it is obtained after intensive mixing and, for example, incorporated into a polymer. Preferably, no separate compacting or compacting step is carried out after the mixing in order to further process the modified organic clay material.

According to a particularly preferred embodiment, the mixture is cooled immediately after intensive mixing. For this purpose, the modified organophilic clay material is preferably cooled to temperatures of less than approximately 40 ° C., in particular less than approximately 30 ° C., particularly preferably of approximately 20 to 40 ° C.

The cooling is preferably carried out over a period of time which corresponds to 1 to 3 times the duration of the previous intensive mixing according to claim 1 c).

The cooled, modified organic clay material can then be removed from the mixing unit and, for example, packed in suitable containers until further processing.

The modified organophilic clay material is preferably cooled actively by cooling the mixture or the high-shear mixing unit used for intensive mixing.

The modified organophilic clay material is preferably cooled in a separate, coolable mixer.

During the cooling, the mixture can be agitated further, in particular mixed further intensively.

A heating-cooling mixer or a combination of a heating mixer and a cooling mixer is preferably used as the high-shear mixing unit. The heating and cooling mixers can be tempered independently of one another, for example with water / steam or heat transfer oil or electrically / hot air / air or water cooling.

For the production of the modified organophilic clay material, it is essential that an intensive swirling of the organophilic clay material and additive takes place. This must be taken into account when choosing the mixing unit. The high shear mixing unit is preferably selected from the group consisting of:<ul id="ul0003" list-style="none"><li>a) paddle mixers, such as ploughshare mixers (Lödige high-speed mixers, Drais high-speed mixers, MTI turbine mixers) with so-called simple or multiple crown tools;</li><li>b) screw mixers, such as screw mixers, which have a twin screw which works either in the same or opposite directions, segment screw mixers, for example coaxial kneaders (BUSS co-kneaders);</li><li>c) Fluid mixers such as rotary mixers, mechanical or pneumatic fluid mixers such as Thyssen, Henschel, Papenmeier or MTI heating mixers, among others</li></ul>

A mechanical fluid mixer can also be used as the high-shear mixing unit, which works according to the fluidized bed principle.

For intensive mixing, high-shear mixing units can also be used, which have stirring tools and preferably at least one discharge plate. The stirring tools are preferably made of stainless steel, in particular of martensitic steels, of RC40 and higher hardened steels. Furthermore, they are preferably corrosion-resistant. Ideally, the fluidizing knives are armored with "Stellite K12" hard metal welding at all relevant points. The distance of the floor scraper from the mixer floor is preferably adjusted to a minimum distance defined by the discharge material and the other fluidizing vanes and the horn tool are arranged in such a way that the required temperatures can be reliably achieved with the fluidizing vanes at a selected filling level of the high-speed mixer.

In order to optimally guarantee the necessary fluidization, a minimum of 1, preferably 2 or more baffle plates are installed. These are arranged in such a way that the surface-modified organophilic clay material is optimally whirled through.

The modified organophilic clay material obtained by the process according to the invention shows improved delamination when incorporated into polymers. In addition, these modified organophilic clay materials show better flow behavior and enable easier dosing when processing plastics in an extruder.

The invention therefore also relates to a modified organophilic clay material, in particular surface-modified particulate, organophilic clay material, which can be obtained by the process described above. The process according to the invention increases the bulk density of the modified organophilic clay material according to the invention and the average particle size decreases. Characteristic of the modified organophilic clay material according to the invention is above all its better delamination in polymers.

The modified organophilic clay material according to the invention can be easily incorporated into polymer materials and is almost completely delaminated (exfoliated). In this way, the modified organophilic clay material according to the invention can impart advantageous properties to these polymer materials, such as, for example, increasing the fire resistance or the scratch resistance of a polymer surface. Another object of the invention is therefore a polymer composition which contains the modified organophilic clay material according to the invention.

The polymer composition preferably contains at least one polymer as polymer, which is selected from the group consisting of polyethylene and copolymers of ethylene, such as HDPE (high density polyethylene), MDPE (medium density polyethylene), LLDPE, VLDPE, LDPE ( low density polyethylene), ULDPE, ethylene-hexene copolymers, ethylene-octene copolymers, polyisobutylene, ethylene-propylene copolymers (EPM), terpolymers of ethylene-propylene-diene (EPDM), EBM (ethylene-butyl rubber), EPDM, ethylene-vinylsilane copolymers, ter- or copolymers of acrylic acid (EA), or ethylene with ethylene acrylate and acrylic acid (EAA) or methacrylic acid (EMA), EEA (ethylene-ethyl acrylate), EBA (ethylene-butyl acrylate), EVA (ethylene -Vinylacetate), grafted copolymers of ethylene with maleic anhydride (MAH), polyvinyl chloride (PVC), polyamide-6, polyamide-66, polyamide-12, polyamide-4, polypropylene and polypropylene copolymers, polyacrylates and polymethacrylates (PMMA), polycarbonate (PC) , Polybutylene terephthalate (PBT), polyethylene terephthalate (PET), fluorinated polymeric hydrocarbons, rubber, TPE's, block copolymers, TPU and polyurethanes; TPO, silicone polymers.

Another object of the invention is the use of the modified organophilic clay material according to the invention as an additive for a polymer composition, in particular as a nanocomposite additive for a polymer composition.

The invention further comprises pre-exfoliated nanocomposite additives which are obtainable by the process according to the invention.

Another object of the invention is a nanocomposite composition which can be obtained by incorporating the pre-exfoliated nanocomposite additive according to the invention into a polymer composition.

The invention is explained in more detail below with the aid of examples and with reference to the attached figures. It shows:<dl id="dl0001"><dt>Fig. 1:</dt><dd>a graphic in which the temperature of the material to be mixed and the current consumption of the mixing unit as a function of the mixing time are given;</dd><dt>Fig. 2:</dt><dd>a graphic representation of a particle size distribution of a commercially available organophilic clay material (Nanofil® 5; Südchemie AG);</dd><dt>Fig. 3:</dt><dd>a graphic representation of a particle size distribution of an organophilic clay material modified according to the invention.</dd></dl>

The parameters mentioned in the examples were determined in the following way:<ul id="ul0004" list-style="none" compact="compact"><li>Particle size distribution (D.₅₀-Value): The grain size distribution was determined by means of laser diffraction in the Mastersizer S (Malvern Instruments GmbH) in a range from 0.05 to 900 µm. A sample of approx. 50 mg is mixed with approx. 10 ml of ethanol in a 20 ml beaker and treated with an ultrasonic finger for 5 minutes. The suspension is transferred to the dispersion unit of the particle size analyzer and ethanol is added until the correct concentration of the sample is set on the measuring device. The measurement is carried out according to the user manual. At the end of the measurement, the result is saved and printed out.</li><li>Bulk density: A sample of the air-dry material is aerated by shaking in a closed vessel so that no mechanically compressed parts are left in the sample.</li></ul>

A 100 ml measuring cylinder, which is cut off at the 100 ml mark, is tared (ml) and then filled with the help of a powder funnel suspended in a holder within about 20 seconds. After 2 minutes the filling cone is drawn off with a ruler. The weight (m2) of the full measuring cylinder is then determined to the nearest 0.01 g.<maths id="math0001" num=""><math display="block"><mrow><mi mathvariant="normal">Bulk density</mi><mi mathvariant="normal"> </mi><mrow><mo>(</mo><mrow><mrow><mi mathvariant="normal">G</mi><mo>/</mo><mi mathvariant="normal">l</mi></mrow></mrow><mo>)</mo></mrow><mo>=</mo><mrow><mo>(</mo><mrow><mi mathvariant="normal">m</mi><mn>2</mn><mo>−</mo><mi mathvariant="normal">m</mi><mn>1</mn></mrow><mo>)</mo></mrow><mo>×</mo><mn>10</mn></mrow></math><img file="EP1560879B1_D0001.tif" /></maths>

Energy consumption: The current consumption of the Henschel heating mixer type FM 200 was determined.

Examples

Example 1 (comparison)

100 g of a highly swellable, natural sodium bentonite are dispersed in high shear water at a temperature of T = 30 ° C. The solids concentration of sodium bentonite in water is 3%. The temperature of the bentonite suspension is increased to 70 ° C. and a predispersed mixture consisting of 90 mmol distearyldimethlymmonium chloride, 14 g rapeseed oil methyl ester (Kebonal® 20, Kebo) and 6.16 g polydiethylsiloxane (Litsolvent® PL, Kebo) are added.

After adding the above mixture to the sodium bentonite, the resulting organophilic bentonite flocculates and is filtered and spray-dried. The powder obtained has a bulk density of 240 g / l.

The particle size distribution was measured from a sample of the organophilic clay material. The values ​​are summarized in Table 1.<tables id="tabl0001" num="0001"><table frame="all"><title>Table 1: Particle size distribution of the organophilic clay material from Example 1</title><tgroup cols="8" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="20mm" colsep="1" /><colspec colnum="2" colname="col2" colwidth="20mm" colsep="1" /><colspec colnum="3" colname="col3" colwidth="21mm" colsep="1" /><colspec colnum="4" colname="col4" colwidth="21mm" colsep="1" /><colspec colnum="5" colname="col5" colwidth="21mm" colsep="1" /><colspec colnum="6" colname="col6" colwidth="21mm" colsep="1" /><colspec colnum="7" colname="col7" colwidth="22mm" colsep="1" /><colspec colnum="8" colname="col8" colwidth="21mm" colsep="1" /><thead><row><entry namest="col1" nameend="col1" align="center" valign="top">Size (µm)</entry><entry namest="col2" nameend="col2" align="center" valign="top">Volume below%</entry><entry namest="col3" nameend="col3" align="center" valign="top">Size (µm)</entry><entry namest="col4" nameend="col4" align="center" valign="top">Volume below%</entry><entry namest="col5" nameend="col5" align="center" valign="top">Size (µm)</entry><entry namest="col6" nameend="col6" align="center" valign="top">Volume below%</entry><entry namest="col7" nameend="col7" align="center" valign="top">Size (µm)</entry><entry namest="col8" nameend="col8" align="center" valign="top">Volume below%</entry></row></thead><tbody><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,060</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">0,00</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">0,600</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">1,17</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">7,0</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">63,23</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">70,00</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,070</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">0,00</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">0,700</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">1,44</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">10,00</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">82,58</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">80,00</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,080</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">0,00</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">0,800</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">1,73</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">15,00</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">95,78</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">90,00</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,090</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">0,00</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">0,900</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">2,08</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">20,00</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">99,35</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">100,00</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,100</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">0,00</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">1,00</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">2,48</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">25,00</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">99,98</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">125, 0</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,200</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">0,07</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">2,00</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">9,38</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">30, 00</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">100,00</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">150,0</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,300</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">0,31</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">3,00</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">20,19</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">40,00</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">100,00</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">175,0</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,400</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">0,61</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">4,00</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">32,22</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">50,00</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">100,00</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">200, 0</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,500</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">0,90</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">5,00</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">43,73</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">60,00</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">100,00</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">250,0</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row></tbody></tgroup></table></tables>

The particle size distribution is shown graphically in FIG. 2. The limit values ​​derived from this particle size distribution are summarized in Table 1a<tables id="tabl0002" num="0002"><table frame="all"><title>Table 1a: Limit values ​​for the particle size distribution</title><tgroup cols="2" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="60mm" colsep="1" /><colspec colnum="2" colname="col2" colwidth="23mm" colsep="1" /><thead><row><entry namest="col1" nameend="col1" align="center" valign="top">limit</entry><entry namest="col2" nameend="col2" align="center" valign="top">Size (µm)</entry></row></thead><tbody><row><entry namest="col1" nameend="col1" align="center" valign="top">D₁₀</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="59">2,07</entry></row><row><entry namest="col1" nameend="col1" align="center" valign="top">D₅₀</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="59">5,59</entry></row><row><entry namest="col1" nameend="col1" align="center" valign="top">D₉₀</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="59">12,06</entry></row><row><entry namest="col1" nameend="col1" align="center" valign="top">D₁₀₀</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="59">26,20</entry></row></tbody></tgroup></table></tables>

Example 2:

100 kg of a nanoclay "Nanofil® 5" from SüdChemie AG with a bulk density of 240 g / l are placed in a heating / cooling mixer, type FM 200 - KM 1000 from Thyssen Henschel. Nanofil® 5 is a bentonite modified with distearyldimethylammonium chloride. The speed of rotation of the mixer is set to 1360 rpm (revolutions per minute) and the temperature is raised to 45 ° C. At this temperature, 10 kg of rapeseed oil methyl ester (Kebonal® 20, Fa. Kebo) and 4.4 kg of polyethylsiloxane (Litsolvent® PL, Kebo) added in the order given as an additive over a period of approx. 30 s. To ensure homogeneous mixing, the additives are added directly to the thrombus generated by the mixing tool. At the specified speed, the reaction mixture is heated up to the discharge temperature of 80 ° C.

The temperature profile during the mixing process can be seen in FIG. 1, furthermore the profile of the current consumption of the mixer. It can be seen that when the temperature of the mixture increases linearly under the selected conditions, a clear current consumption of the mixer is observed after about 7.5 minutes. In order to prevent complete agglomeration of the powder, and thus ultimately a further deterioration in the dispersibility of the nanoclay in polymers, the mixing process is stopped at a temperature of 80 ° C. and after 7.5 minutes.

An organophilic clay material which has been surface-modified with the two additives and has a bulk density of 480 g / l is obtained. The modified organophilic clay material is in the form of a finely divided powder with the particle size distribution shown in Table 2. The particle size distribution is also shown graphically in FIG. 3.<tables id="tabl0003" num="0003"><table frame="all"><title>Table 2: Particle size distribution of the modified organophilic clay material from Example 1</title><tgroup cols="8" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="20mm" colsep="1" /><colspec colnum="2" colname="col2" colwidth="20mm" colsep="1" /><colspec colnum="3" colname="col3" colwidth="21mm" colsep="1" /><colspec colnum="4" colname="col4" colwidth="21mm" colsep="1" /><colspec colnum="5" colname="col5" colwidth="21mm" colsep="1" /><colspec colnum="6" colname="col6" colwidth="21mm" colsep="1" /><colspec colnum="7" colname="col7" colwidth="22mm" colsep="1" /><colspec colnum="8" colname="col8" colwidth="21mm" colsep="1" /><thead><row><entry namest="col1" nameend="col1" align="center" valign="top">Size (µm)</entry><entry namest="col2" nameend="col2" align="center" valign="top">Volume below%</entry><entry namest="col3" nameend="col3" align="center" valign="top">Size (µm)</entry><entry namest="col4" nameend="col4" align="center" valign="top">Volume below%</entry><entry namest="col5" nameend="col5" align="center" valign="top">Size (µm)</entry><entry namest="col6" nameend="col6" align="center" valign="top">Volume below%</entry><entry namest="col7" nameend="col7" align="center" valign="top">Size (µm)</entry><entry namest="col8" nameend="col8" align="center" valign="top">Volume below%</entry></row></thead><tbody><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,060</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">0,00</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">0,600</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">2,51</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">7,0</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">86,52</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">70,00</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,070</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">0,00</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">0,700</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">3,16</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">10,00</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">96,15</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">80,00</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,080</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">0,01</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">0,800</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">3,97</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">15,00</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">99,64</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">90,00</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,090</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">0,02</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">0,900</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">5,01</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">20,00</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">100,00</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">100,00</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,100</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">0,02</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">1,00</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">6,21</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">25, 00</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">100,00</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">125,0</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,200</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">0,26</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">2,00</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">23,35</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">30,00</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">100,00</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">150,0</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,300</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">0,83</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">3,00</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">42,41</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">40,00</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">100,00</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">175,0</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,400</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">1,41</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">4,00</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">58,43</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">50,00</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">100,00</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">200,0</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row><row><entry namest="col1" nameend="col1" valign="top" align="char" char="." charoff="60">0,500</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="56">1,93</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="59">5,00</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="59">70,95</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="61">60,00</entry><entry namest="col6" nameend="col6" valign="top" align="char" char="." charoff="64">100,00</entry><entry namest="col7" nameend="col7" valign="top" align="char" char="." charoff="63">250,0</entry><entry namest="col8" nameend="col8" valign="top" align="char" char="." charoff="64">100,00</entry></row></tbody></tgroup></table></tables>

The limit values ​​determined from the particle size distribution are summarized in Table 2a.<tables id="tabl0004" num="0004"><table frame="all"><title>Table 2a: Limit values ​​for the particle size distribution</title><tgroup cols="2" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="60mm" colsep="1" /><colspec colnum="2" colname="col2" colwidth="23mm" colsep="1" /><thead><row><entry namest="col1" nameend="col1" align="center" valign="top">limit</entry><entry namest="col2" nameend="col2" align="center" valign="top">Size (µm)</entry></row></thead><tbody><row><entry namest="col1" nameend="col1" align="center" valign="top">D₁₀</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="59">1,26</entry></row><row><entry namest="col1" nameend="col1" align="center" valign="top">D₅₀</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="59">3,45</entry></row><row><entry namest="col1" nameend="col1" align="center" valign="top">D₉₀</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="59">7,74</entry></row><row><entry namest="col1" nameend="col1" align="center" valign="top">D₁₀₀</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="59">19,31</entry></row></tbody></tgroup></table></tables>

If the mixing process continues at temperatures above 80 ° C., agglomerates with a significantly coarser particle size distribution than that shown in FIG. 3 form.

The surface-modified organophilic clay material is cooled to a temperature between 20 and 40 ° C at low speed. For this purpose, the modified organophilic clay material heated to 80 ° C. is transferred to a second mixer, which comprises a cooling device and in which the mixture is cooled to a temperature between 20 and 40 ° C.

The bulk density of the powder obtained is 480 g / l. Samples were taken at regular intervals during the experiment and the bulk density was determined. The results are summarized in Table 3.<tables id="tabl0005" num="0005"><table frame="all"><title>Tab. 3: Change in bulk density during the modification</title><tgroup cols="10" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="30mm" colsep="1" /><colspec colnum="2" colname="col2" colwidth="11mm" colsep="1" /><colspec colnum="3" colname="col3" colwidth="11mm" colsep="1" /><colspec colnum="4" colname="col4" colwidth="11mm" colsep="1" /><colspec colnum="5" colname="col5" colwidth="11mm" colsep="1" /><colspec colnum="6" colname="col6" colwidth="11mm" colsep="1" /><colspec colnum="7" colname="col7" colwidth="11mm" colsep="1" /><colspec colnum="8" colname="col8" colwidth="11mm" colsep="1" /><colspec colnum="9" colname="col9" colwidth="11mm" colsep="1" /><colspec colnum="10" colname="col10" colwidth="11mm" colsep="1" /><thead><row><entry namest="col1" nameend="col1" align="center" valign="top">Mixing time (min)</entry><entry namest="col2" nameend="col2" align="center" valign="top">1</entry><entry namest="col3" nameend="col3" align="center" valign="top">2</entry><entry namest="col4" nameend="col4" align="center" valign="top">3</entry><entry namest="col5" nameend="col5" align="center" valign="top">4</entry><entry namest="col6" nameend="col6" align="center" valign="top">5</entry><entry namest="col7" nameend="col7" align="center" valign="top">6</entry><entry namest="col8" nameend="col8" align="center" valign="top">7</entry><entry namest="col9" nameend="col9" align="center" valign="top">7,5</entry><entry namest="col10" nameend="col10" align="center" valign="top">8</entry></row></thead><tbody><row><entry namest="col1" nameend="col1" align="center" valign="top">Bulk density (g / l)</entry><entry namest="col2" nameend="col2" align="center" valign="top">240</entry><entry namest="col3" nameend="col3" align="center" valign="top">242</entry><entry namest="col4" nameend="col4" align="center" valign="top">242</entry><entry namest="col5" nameend="col5" align="center" valign="top">267</entry><entry namest="col6" nameend="col6" align="center" valign="top">280</entry><entry namest="col7" nameend="col7" align="center" valign="top">301</entry><entry namest="col8" nameend="col8" align="center" valign="top">344</entry><entry namest="col9" nameend="col9" align="center" valign="top">480</entry><entry namest="col10" nameend="col10" align="center" valign="top">560</entry></row></tbody></tgroup></table></tables>

Table 3 shows that the bulk density increases after about 4 minutes of mixing time and that after a mixing time of 7 to 8 minutes there is a significant increase in the bulk weight. This corresponds to the period after which an increase in the current consumption of the mixer is also observed.

A comparison of the particle size distribution of the organophilic clay material modified according to the invention (FIG. 3) with the organophilic clay material Nanofil® 5 (FIG. 2) used for the production shows that a finer particle size distribution can be achieved by the dry mixing process according to the invention.

The D₅₀The values ​​of the organophilic clay materials obtained in Examples 1 and 2 are listed again in Table 4 for comparison.<tables id="tabl0006" num="0006"><table frame="all"><title>Table 4: D₅₀-Values ​​of organophilic clay materials</title><tgroup cols="2" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="58mm" colsep="1" /><colspec colnum="2" colname="col2" colwidth="16mm" colsep="1" /><tbody><row><entry namest="col1" nameend="col1" align="left" valign="top">Nanofil® 5 (example 1)</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="69">5.6 µm</entry></row><row><entry namest="col1" nameend="col1" align="left" valign="top">Example 2</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="69">3.4 µm</entry></row></tbody></tgroup></table></tables>

The following advantages are thus achieved by the surface modification according to the invention (example 2):<ul id="ul0005" list-style="dash" compact="compact"><li>Increase in bulk density by 100%;</li><li>Reduction in particle size;</li><li>Improvement of the mechanical properties of polypropylene, which could be demonstrated by the following incorporation of the organophilic clay materials from example 1 and example 2.</li></ul>

Example 3, compounding

The organophilic clay materials obtained from Example 1 and Example 2 are compounded into the blow molding polypropylene type RB 307 MO (manufacturer: Borealis) as follows:

A synchronized laboratory twin screw extruder of the type ZE 25 (Berstorff) is used. All formulation components are dosed gravimetrically into the main funnel. The emerging compound strands are cooled in a water bath and granulated.

It is extruded in a process step with a temperature profile of 180 ° C to 225 ° C. The screw speed is 300 revolutions per minute. The throughput is 10 kg / hour.

Test specimens were produced from the granules obtained on an Ergotech 100 / 420-310 (Demag) injection molding machine. The modulus of elasticity (E_t) according to ISO 527-2 / 1A / 50 and the notched impact strength (Sharpy) according to ISO 179 / 1EU at 23 ° C. The values ​​found are shown in Table 5.<tables id="tabl0007" num="0007"><table frame="all"><title>Table 5: Properties of test specimens</title><tgroup cols="5" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="18mm" colsep="1" /><colspec colnum="2" colname="col2" colwidth="27mm" colsep="1" /><colspec colnum="3" colname="col3" colwidth="20mm" colsep="1" /><colspec colnum="4" colname="col4" colwidth="30mm" colsep="1" /><colspec colnum="5" colname="col5" colwidth="44mm" colsep="0" /><thead><row><entry namest="col1" nameend="col1" align="left" valign="top" /><entry namest="col2" nameend="col2" align="center" valign="top">RB 307 Mo (%)</entry><entry namest="col3" nameend="col3" align="center" valign="top">Additive (%)</entry><entry namest="col4" nameend="col4" align="center" valign="top">E-module E_t (GPa)</entry><entry namest="col5" nameend="col5" align="center" valign="top">Notched impact strength (kJ / m²)</entry></row></thead><tbody><row><entry namest="col1" nameend="col1" align="left" valign="top">example 1</entry><entry namest="col2" nameend="col2" align="center" valign="top">5</entry><entry namest="col3" nameend="col3" align="center" valign="top">-</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="54">0,68</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="53">14,7</entry></row><row><entry namest="col1" nameend="col1" align="left" valign="top">Example 2</entry><entry namest="col2" nameend="col2" align="center" valign="top">-</entry><entry namest="col3" nameend="col3" align="center" valign="top">5</entry><entry namest="col4" nameend="col4" valign="top" align="char" char="." charoff="54">0,79</entry><entry namest="col5" nameend="col5" valign="top" align="char" char="." charoff="53">20,9</entry></row></tbody></tgroup></table></tables>

As can be seen from Table 5, the additive from Example 2 gave improved properties with respect to the modulus of elasticity and the impact strength.

Example 3

Example 2 was repeated, but the mixing of the organophilic clay material with the additive was carried out not using a heating / cooling mixer but using an intensive mixer from Eirich, with the heat being omitted during the mixing process. The components Nanofil® 5 (1 kg), Kebonal 20 (100 g) and Lithosolvent PL (44 g) were placed in the mixing container. The container was placed in the mixer and whirlers and turntables started.<tables id="tabl0008" num="0008"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="40mm" colsep="0" /><colspec colnum="2" colname="col2" colwidth="16mm" colsep="0" /><tbody><row><entry namest="col1" nameend="col1" align="left" valign="top">Fill level of the container:</entry><entry namest="col2" nameend="col2" align="left" valign="top">approx. 80%</entry></row><row><entry namest="col1" nameend="col1" align="left" valign="top">Vortex drive:</entry><entry namest="col2" nameend="col2" align="left" valign="top">Level 2</entry></row><row><entry namest="col1" nameend="col1" align="left" valign="top">Turntable drive:</entry><entry namest="col2" nameend="col2" align="left" valign="top">Level 2</entry></row><row><entry namest="col1" nameend="col1" align="left" valign="top">Bulk weight Nanofil® 5:</entry><entry namest="col2" nameend="col2" align="left" valign="top">243 g / l</entry></row></tbody></tgroup></table></tables>

During the mixing process, the temperature of the mix and the current consumption of the mixer were regularly determined. Samples were also taken at regular intervals and the bulk density was determined. The values ​​are summarized in Table 6.<tables id="tabl0009" num="0009"><table frame="all"><title>Table 6: Process parameters when using an intensive mixer</title><tgroup cols="4" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="28mm" colsep="1" /><colspec colnum="2" colname="col2" colwidth="22mm" colsep="1" /><colspec colnum="3" colname="col3" colwidth="28mm" colsep="1" /><colspec colnum="4" colname="col4" colwidth="25mm" colsep="1" /><thead><row><entry namest="col1" nameend="col1" align="center" valign="top">time</entry><entry namest="col2" nameend="col2" align="center" valign="top">temperature</entry><entry namest="col3" nameend="col3" align="center" valign="top">Power consumption</entry><entry namest="col4" nameend="col4" align="center" valign="top">Bulk density</entry></row><row><entry namest="col1" nameend="col1" align="center" valign="top">min</entry><entry namest="col2" nameend="col2" align="center" valign="top">° C</entry><entry namest="col3" nameend="col3" align="center" valign="top">A</entry><entry namest="col4" nameend="col4" align="center" valign="top">g / l</entry></row></thead><tbody><row><entry namest="col1" nameend="col1" align="center" valign="top">1</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="55">19,5</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="51">5,5</entry><entry namest="col4" nameend="col4" align="center" valign="top">274</entry></row><row><entry namest="col1" nameend="col1" align="center" valign="top">2</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="55">19,7</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="51">5,5</entry><entry namest="col4" nameend="col4" align="center" valign="top">271</entry></row><row><entry namest="col1" nameend="col1" align="center" valign="top">3</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="55">19,6</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="51">5,5</entry><entry namest="col4" nameend="col4" align="center" valign="top">281</entry></row><row><entry namest="col1" nameend="col1" align="center" valign="top">4</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="55">19,6</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="51">5,5</entry><entry namest="col4" nameend="col4" align="center" valign="top">295</entry></row><row><entry namest="col1" nameend="col1" align="center" valign="top">5</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="55">19,7</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="51">5,5</entry><entry namest="col4" nameend="col4" align="center" valign="top">289</entry></row><row><entry namest="col1" nameend="col1" align="center" valign="top">6</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="55">19,7</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="51">5,5</entry><entry namest="col4" nameend="col4" align="center" valign="top">284</entry></row><row><entry namest="col1" nameend="col1" align="center" valign="top">7</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="55">19,5</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="51">5,5</entry><entry namest="col4" nameend="col4" align="center" valign="top">292</entry></row><row><entry namest="col1" nameend="col1" align="center" valign="top">8</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="55">19,6</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="51">5,5</entry><entry namest="col4" nameend="col4" align="center" valign="top">296</entry></row><row><entry namest="col1" nameend="col1" align="center" valign="top">9</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="55">19,6</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="51">5,5</entry><entry namest="col4" nameend="col4" align="center" valign="top">287</entry></row><row><entry namest="col1" nameend="col1" align="center" valign="top">10</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="55">19,7</entry><entry namest="col3" nameend="col3" valign="top" align="char" char="." charoff="51">5,5</entry><entry namest="col4" nameend="col4" align="center" valign="top">294</entry></row></tbody></tgroup></table></tables>

Furthermore, the particle size distribution of the starting material and of the product obtained was measured and the D₅₀-Value determined. The results are summarized in Table 7.<tables id="tabl0010" num="0010"><table frame="all"><title>Table 7: D₅₀-Value when mixed in the intensive mixer.</title><tgroup cols="2" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="66mm" colsep="1" /><colspec colnum="2" colname="col2" colwidth="17mm" colsep="1" /><tbody><row><entry namest="col1" nameend="col1" align="left" valign="top">Source material</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="68">7.7 µm</entry></row><row><entry namest="col1" nameend="col1" align="left" valign="top">End product</entry><entry namest="col2" nameend="col2" valign="top" align="char" char="." charoff="68">5.6 µm</entry></row></tbody></tgroup></table></tables>

As can be seen in Table 7, the temperature of the mix does not increase during the mixing process. Furthermore, no increase in the mixer current consumption was observed during the mixing time. The bulk density of the modified organophilic clay material increased only slightly.