Method for producing nanocomposite additives with improved delamination in polymers

Translation of description of equivalent WO 2004111122 A1

METHOD FOR PRODUCING nanocomposite ADDITIVES WITH

IMPROVED DE LAMIN I ERUN G 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, such as can be obtained with the method according to the invention, a polymer composition containing the modified organophilic clay material, the use of the modified organophilic clay material, pre-exfoliated nanocomposite additives, and a nanocomposite composition.

The properties of plastics or generally older poly materials can be improved by the addition of nanocomposite additives. These allow a modification of the mechanical properties or gas permeation. Further, the flame retardant properties can be improved by the addition of nanocomposite additives, for example. During combustion of the polymer a stable crust layer is formed, which pushes back a further ignition of the polymer.

Nanocomposite additives consist of natural or synthetic phyllosilicates whose surfaces with organic molecules molecules are modified. Through the organic modification, an adaptation of the surface polarity of the nanocomposite additives is obtained at the polarity of the polymers, in which the nanocomposite additives are incorporated.

Nanocomposite additives are, for example, prepared by a swellable layer silicate, such as montmorillonite or hectorite is dispersed and delaminated in water. The organic modification example, by the addition of quaternary ammonium compounds, which are bound by cation exchange to the negatively charged surface layers of Silicatlamel- len. By the polarity of the organic component, the polarity of the organically modified Schichtsi- licats can be influenced and thus matched to the polarity of the plastics used. For incorporation of the nanocomposite additives into polymers two paths can be labeled:

a) in-situ polymerization

In the in-situ polymerization, the nanocomposite additive is dispersed in a monomer, with a delamination of the layers of the layered silicate occurs. The monomer can also penetrate into the space between the adjacent silicate layers and cause a Schichtauf eitung there. During the subsequent polymerization of polymerizing the monomers penetrated into the gaps, whereby the silicate layers are separated from each other. In a subsequent dispersing step an extensive delamination of the layers is carried out. To achieve very complete delamination, the nanocomposite additive must be compatible in its surface properties both with the monomer and with the resulting polymer. b) melting ompoundierung

In the melt compounding the pul erförmige nanocomposite additive is dispersed in an extruder in the polymer melt. At a sufficient compatibility of the surface properties of the nanocomposite additive with the polymer delamination of the organically modified phyllosilicate lamellae already occurs during the extrusion process.

A complete as possible delamination of the nanocomposite additive is a precondition for the desired improvements in mechanical properties, gas permeation and the flame retardant in plastics can be achieved.

The nanocomposite additives previously used as additives for polymeric materials consist of a sheet silicate which is a cationic organic component and, optionally, still further, the polarity of the layered silicate-influencing components modified. For the preparation of the nanocomposite additives first the layer silicate is dispersed in water and then added to the cationic organic component at a temperature of about 80 ° C. After addition of the cationic organic component is followed by a precipitation of the modified layered silicate, which is then separated by filtration, dried and milled. Thus, in US 4,695,402 a process for the preparation of organically modified bentonites will be described. Here, a slurry of the layered silicate is first stirred under high shear conditions and then added an organic cation in an amount which is approximately 90 to 150% of the capacity of the layered Kationenaustauschka- equivalent. The organically modified phyllosilicate is isolated from the ung Aufschläm and then dried under mild conditions below about 50 ° C. Suitable organic cations, for example ammonium, phosphonium or sulfonium compounds may be used be that carry long-chain linear or branched alkyl chains.

In US 4,429,999 an organically modified layered silicate is prepared by first a layered, for example, montmorillonite, bentonite or hectorite, is slurried in water. The slurry is heated to temperatures of about 70 ° C and then added successively two different organic cations. Suitable organic cations, quaternary ammonium salts, phosphonium, sulfonium umsalze and mixtures thereof may be used for example. The slurry added to up amount of the first organic cation corresponds to about 75 to 150% of the cation exchange capacity of the layered silicate. The amount of the second organic cation corresponding to about 0.01 to 20 wt .-%, based on the total amount of the organic cation. Subsequently, one or more organic anions are added, which can react with the first and / or second organic cations to form a complex with the layered silicate. The first organic cation contains hydrophobic groups whereas the second organic cation contains hydrophilic groups. The reaction product is then separated by filtration and dried under mild conditions.

In EP 0627480 AI an organically modified layered silicate is described, which is obtained by first preparing an aqueous slurry of a layered silicate is prepared. The slurry is heated to temperatures of about 70 ° C and then added an organic cation. The organophilic layer silicate may further contain an organic anion, such as sodium stearate. Both the addition of the organic cation and the organic anion is carried to the aqueous slurry of the layered silicate. The reaction product is separated by filtration and then dried under mild conditions.

In US 4,874,728 an organophilic layer silicate is described, which is obtained by first adding a quaternary ammonium salt is added to an aqueous slurry of a layered silicate which carries long-chain alkyl groups. The reaction product is then separated by filtration and dried.

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

The preparation of organophilic bentonites in the form of a dry mixing process, bypassing the pre-dispersion of the sodium bentonite in water is described for example in US 4,474,706. Here, a substantially dry, swellable clay without the addition of water is reacted with an organic ammonium compound. For this purpose, the clay and the ammonium compound are mixed at temperatures above the melting point of the ammonium compound. The components are mixed together so long, until all liquid is 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 the increase in the distance between adjacent layers of the clay. For the modification of mixtures of different ammonium compounds are preferably used. The ammonium salts can be added individually or as a mixture in any order to the dry clay. The temperature at which the mixing of the components takes place must be chosen to be higher than the melting point of the highest melting quaternary ammonium compound. The modified clay may be washed with water and then dried again and then optionally ground. To achieve a reaction between clay and ammonium salt, an intensive mixing of the components is required. This can be verreicht example, by using a mortar and pestle in a reaction in the laboratory scale. If implemented on an industrial scale, for example, a ribbon blender (ribbon blender) or an extruder may be used. While mixing, a slight warming of the reaction mixture is observed, which is produced by compression and friction.

In DE 31 45 043 Al a process for preparing organophilic clays is described. 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 repeatedly compressed dry and then ground again to prepare an organophilic clay. For the production of organically modified clay, the clay sample is first introduced into a mixer and sufficient water is added to adjust the sound to a moisture content of 12 wt .-% in the examples. The required amount of water dissolved in the quaternary ammonium salt is added and the mixture thoroughly mixed. After mixing, the sample is passed through a two roll system in which the reaction mixture is compressed under high pressure. The resultant compacted organophilic clay needs no further drying, but is merely crushed and sieved to the desired particle size.

In WO 97/31873 a process for preparing an organically modified clay is described which has been prepared by a dry method, and the directly as an additive can be introduced into the solvent. For this purpose, the clay with a mixture of a quaternary ammonium salt and an aprotic polar solvent is treated, 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, wherein the reaction mixture is mixed until the polar aprotic solvent can react with the clay particles. For mixing conventional mixer or extruder can be used that provide sufficient shear to cause a reaction of the clay with the organic materials. After the reaction, the product obtained can be optionally dried and milled.

In order to use the nanocomposite additives technically, they have to be exfoliated in the polymer. This exfoliation the original short-range order is lost in the phyllosilicates. The phyllosilicates are split into individual tiles that comprise only single silicate layers. Completely exfoliated smectites may form platelet-shaped particles. A very high aspect ratio of up to 1,000 exhibiting These particles correspond platelets having a thickness in the range of about 1 nm, a width of about 100 nm and a length in the range of about 500 to 1,000 nm. In case of incorporating the nanocomposite additives in a plastic matrix, in some polymers, although an increase in observed of the layer separation, ie, the polymer is partly incorporated into the intermediate spaces between adjacent lamellae of the layered silicate. However, it will be no complete exfoliation of the nanocomposite additive in the polymer. In polymer are currently larger particles, which are formed from agglomerates of platelets described above. This adversely affects the mechanical properties and extrudability of polymer compositions out. Nor can the nanocomposite additives distribute difficulties uniformly in the polymer composition.

The present invention was therefore based on the object, a method for producing organically modified phyllosilicates to provide showing during incorporation into plastics improved delamination, ie in which during incorporation into a polymer mass almost complete exfoliation takes place.

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

The inventive method for modification, in particular for the surface modification of an organophilic clay material, comprising the steps of:

a) providing a dry strength pulverför, organophilic clay material (component a); b) providing at least one additive (component b) for the modification of component a); c) Intensive mixing of the components a) and b) in a high shear mixing apparatus.

wherein no water or solvent is added or is used for the addition of component b).

The inventive process is itself an organophilic clay material. As organophilic clays organically modified nanocomposite additives can for example be used as they are already known for use in polymer compositions. The inventive method of implementation of the organophilic clay material with the additive, an intensive mixing of organophilic clay material and additive is done in a high-shear mixing assembly, is a modified ed organophilic clay material is obtained, which can be much easier and more completely exfoliated during incorporation into a polymer composition. The proportion of aggregates, which are composed of more lamellae can be significantly reduced. This can be seen for example in electron micrographs. The preparation of the organophilic clay material can be effected in any per se. Preferably, the organophilic clay material is prepared according to the general procedure described above, first prepared in which an aqueous suspension of raw clay and this is then reacted with an organic modifier. Here can be made of known methods such as those described for example in the introduction.

Raw clays conventional swellable phyllosilicates can be used. These can be obtained from natural sources or synthetically prepared. Particularly useful are smectic te, such as montmorillonite, hectorite, saponite, and beidellite. Bentonites can also be used. Due to the better swelling properties, the raw clays are preferably used in their sodium form.

The organic modifier agent all the known modifiers may be used per se. Particularly suitable cationic organic agents, such as ammonium compounds which carry at least one long-chain carbon chain which, for example, 12 to 22 carbon atoms and - sums. Preferably, the ammonium compound preferably comprises two relatively long carbon chains. The carbon chains may be the same or different and are linear or branched. Examples of suitable carbon chains are lauryl, stearyl, tridecyl, myristyl, pentadecyl and hexadecyl groups. Examples of relatively long branched carbon chains are the 12- Methylstearyl- or the 12-ethylstearyl. A particularly preferred carbon ette is stearyl. The other Valences of the nitrogen atom are preferably satisfied with shorter carbon chains which may comprise 1 to 22 carbon atoms. Particularly preferably, the other valencies of the nitrogen atom are saturated by methyl groups. However, it is also possible that the free valencies are saturated by Wassersto fatome. The bonded to the nitrogen carbon chains may be saturated or unsaturated and include, for example, and aromatic groups. Thus, the ammonium compound alongside the long carbon chains, for example, bear benzyl groups also. The ammonium compounds can be used for example as chlorides. In addition to the ammonium compounds, the analogous phosphonium and sulphonium compounds may be used for the preparation of the organophilic clay material, for example. Organophilic clays modified with ammonium compounds are, as a starting material for the process according to the invention particularly preferred.

The organophilic clay material is modified by means of an additive. As additives for modifying the organophilic clay material, for example, the following compounds can be used:

Fatty acids or fatty acid derivatives are preferably selected from fatty acids having 10 - 13 carbon atoms. Here lauric acid, palmitic acid, stearic acid, oleic acid, linoleic acid, caproic and castor oil are mentioned 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 the polymeric fatty acids, the keto fatty acids, the fatty acid alkyloxazolines and fatty acid alkylbisoxazolines, or mixtures thereof. The unsaturated fatty acids, in particular the mono- or poly-unsaturated hydroxy fatty acids are mentioned. Furthermore, can not be used anionic, organic components which contain at least one aliphatic or cyclic radical having 6 - 18 carbon atoms comprise - 32 carbon atoms, preferably 8-22 Kohlenstoffato s, in particular 10th Particularly preferred are those anionic, organic components from a fatty acid derivatives of the following substance classes:

1. fatty alcohols, saturated or unsaturated, including primary and secondary alcohols, in particular with Cε ^_ C₂₂radicals;

2. fatty aldehydes, ketones;

3. Fettalkoholpolyglykolether;

4. fatty amines;

5. mono-, di- and triglyceride esters;

6 fatty acid;

7. Fatty acid amides;

8. fatty;

9. Fettsäureglukamide;

10. dicarboxylic;

11. waxes;

12. Water-insoluble fatty acid soaps (these being the salts of long chain carboxylic acids with divalent metals;

13. Montan waxes (these being waxes are having a chain length of C₂₆ - C₃₂ to understand) ;

14 paraffins and PE waxes.

Especially preferred are fatty alcohols, fatty amides, triglyceride esters, fatty acids, and waxes.

Siloxane components may be used, among loxanderivate IUPAC guidelines these are oligomeric or polymeric siloxanes or safety are to be understood. Siloxane derivatives are preferably those in which at least one of the CH₃-Seitengrup- pen is replaced on the Si atom by another functional group. Particular preference, without limitation, Oligoalkylsi- Loxane, polydialkylarylsiloxanes, polydiarylsiloxanes, or a mixture thereof, wherein said siloxane are particularly preferred which have been onalisiert function- with at least one reactive group.

The mixing of organophilic clay and additive is carried out in the inventive process without addition of water or another solvent. The organophilic clay material preferably has a very low moisture content or solvent content, that no clumping can occur during the mixing or no plastic deformation can be carried out, as required, for example during extrusion. Preferably, the organophilic clay material know a moisture content or a solvent content of less than 10 wt .-%, in particular less than 5 wt .-% to. The additive is added without dilution. Optionally, the additive may be melted before addition.

The organophilic clay material is added as a powder into the high-shear mixing assembly. The organophilic clay material is ground to a small particle size. Preferably, the mean particle size is (D₅o value) below 50 microns, preferably below a Dso value of 30 microns, especially less than 8 microns. The bulk density of the organophilic clay material is preferably less than 300 g / 1, and is particularly preferably in the range of 150 to 250 g / 1st The determination of D₅₀-value And the bulk density will be explained below in the experimental part of the description.

The organophilic clay and the additive takes place in a high-shear mixing assembly. A high-shear mixing assembly here is a mixer understood where each other the components of the mixture under high shear the mixed without causing is a substantial densification or compacting. During the mixing process, the mixture of organic clay material and additive retains the form of a loose powder. After mixing, in contrast to the modification previously known methods that is, a powder is obtained directly, which can be incorporated, for example in polymer compositions. So it is not necessary to marry the modified organophilic clay material.

During the mixing process, intensive fluidization of the components a high energy input takes place. At the same time an increase in the temperature of the mix is ​​observed during the intensive mixing process. At the beginning of the mixing process is approximately constant electrical current consumed by the mixer. Once the mixing procedure has proceeded further, the current consumption of the mixer and thus the energy input into the mixture increases. The powder begins to agglomerate. Furthermore, the bulk density of the powder increases. The mixing process is preferably carried out in such a way that by the intensive mixing process brings high energy input, the mixture of organic clay material and additive within a few minutes, for example, 6 to 8 minutes, is placed on a temperature at which the power consumption of the mixer non- increases linearly. The mixing procedure is terminated only after an increased power consumption has been observed at the mixer for some time. After the optimum mixing time is exceeded, the current consumption increases significantly. This constitutes a criterion for stopping the mixing process.

It is believed that constantly new surfaces are created on the organophilic clay material by the intensive mixing at an elevated temperature, which come into contact with the additive. It thereby takes place a coating of the surface of the organophilic clay material with the additive. The additive is probably to some extent incorporated in the intermediate spaces of adjacent slats. It causes a change in the porosity of the organophilic clay material, and a change in the capillary. This improves delaminatability the modified organophilic clay material in polymers. Besides improved delamination, improved flowability of the modified organophilic clay material and an improved controllability is observed during the extrusion process.

Preferably, the intensive mixing of organophilic clay material and additive at elevated temperature is performed. As already mentioned above, the during the intensive mixing high energy input causes heating of the mixture, and after an initial mixing period the nonlinear energy consumption of the mixture is observed.

Preferably, the energy is introduced into the mix, not only through the mixer, but the mix is ​​additionally heated. For this purpose, the mixing material, uniformly heated, for example by means of a heating jacket. For heating, a linear heating profile may for example be selected. The heating is preferably continued until a non-linear increase in the energy consumption of the mixer indicates reaction between organophilic clay material and additive.

Preferably, the temperature up to which the mixed material formed from organophilic clay material and additive, is heated higher than the melting point of the selected at least one additive. If more than one additive in the mixture is present, the temperature is selected so that it lies above the melting point of the highest melting additive.

Preferably, the temperature of the mixture is increased during the intensive mixing. As already explained above, the temperature of the mixture can first be increased by an additional supply of heat until the increased energy input would take the mixer indicates reaction between organophilic clay material and additive. Even after this point the mixing of organophilic clay material and additive is reached, the temperature is preferably further increased. The temperature increase can be carried out by the energy input of the mixer or by an external heat supply.

The intensive mixing of organophilic clay material and additive is preferably carried out in a temperature range of 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. Preferably, during the intensive mixing the organophilic clay material, an increase in the bulk density of at least 20%, preferably at least 40%, particularly 60%, particularly preferably 80%, more preferably at least 100%, based on the bulk density of the shaped powder-used, is achieved.

The components of the mixer, organophilic clay material and additive, are mixed together with high energy input. The energy input can be achieved by the energy consumption of the mixer, so the power consumed during the intensive mixing electric power, determine which is then placed in relation to the volume of the mixture. preferably takes place during the intensive mixing an energy input of at least 300 kW / m³,

The intensive mixing is preferably performed until an increase of the energy input as measured by the current consumption of the high-shear mixing assembly, at least 10%, preferably at least 20% is achieved.

As already explained, after an induction period, a non-line linear increase of the energy input of the mixing assembly is observed. Preferably, the intensive mixing is continued continued until the increase in the energy input at the end of the intensive mixing of claim 1 c), as measured by the current consumption of the high-shear mixing assembly, in the range between 10 and 50%, especially between 20 and 30%, starting from the current consumption of the high-shear stirrer assembly at the start the intensive mixing is.

In particular, the intensive mixing is at least as long as carried out until the current consumption of the mixing assembly increases within one minute to at least 20%.

If the increase in power consumption described above is not reached after a total period of intensive mixing of about 5 min., The high-shear mixing assembly used is preferably additionally heated.

During the intensive mixing process, the organophilic clay material retains the form of a powder. Due to the intense turbulence of the particles, the organophilic clay material is reacted with the additive and coated. The intensity of the mixing procedure and its duration is chosen so that the particle size, measured as D₅₀To not more than 10% increases during the intensive mixing. Particularly preferable that the particle size, measured as D₅₀, Does not fall to or even. The change in the particle size of the modified organophilic clay material always refers to the original particle size, measured as D₅₀, The component used for the intensive mixing a). Preferably, the particle size is D₅₀ of the modified organophilic clay material in the range of about 20 to 5 microns.

During the intensive mixing process the bulk density of the organophilic clay material increases. The mixing is preferably terminated when the bulk density has increased from the initial bulk density of component a) to a maximum of 200%. By the intensive mixing the Schüttge- increases So weight to a maximum of three times the bulk density of the untreated organophilic clay material. Preferably, the bulk density of the modified organophilic clay material is in the range of 400 to 550 g / 1st

The additive is added without dilution to the organophilic clay material. According to one embodiment of the inventive process both component a) and component b) is used in powder form. The powdery fine grain solids behave like a liquid when mixing. A vortex is formed, so that the product is moved in horizontal and vertical direction intensively. The intense energy input results in a temperature increase of the mixed material to a non-linear increase in the current consumption of the mixer, resulting in an increase in the bulk density of the powder. However, it may also be used additives, which are liquid at room temperature. These are preferably added in a way the organophilic clay material that directly intensive mixing takes place, the additive does not pung to Verklum- the organophilic clay material performs. Preferably, the liquid additive is added in the vicinity of a developing during the fluidization of the organophilic clay material. The mixture of organic clay material and additive is agitated in the mixing unit in a manner so that at peripheral speeds up to 200 m / s, a thrombus occurs. During the mixing process an .Kegelbildung is observed in the center of the mixing vessel., Ie, the mixed material is drawn to the bottom of the mixing unit during the intensive mixing process in the form of a cone.

In the inventive method, the organophilic clay material both before and after the modification in the form of a powder. Preferably, the modified organophilic clay material is, as obtained after the intensive mixing, further processed and, for example, in a polymer incorporated. Preferably, after mixing, no separate compacting or densifying step is carried out to further edit the modified organic clay material.

According to a particularly preferred embodiment, immediately after the intensive mixing, cooling of the mixture. For this, the modified organophilic clay material is preferably cooled to temperatures of less than about 40 ° C, especially less than about 30 ° C, more preferably from about 20 to 40 ° C.

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

The cooled modified organic clay material can then be removed from the mixing assembly and packaged for example until further processing into suitable containers.

Preferably, the cooling of the modified organophilic clay material is actively cooling the mixture or high shear mixing assembly used for the intensive mixing.

The cooling of the modified organophilic clay material is preferably carried out in a separate, coolable mixer.

During cooling, the mixture may further agitated, and in particular intensive mixed.

High-shear mixing unit, a heating-cooling mixer or a combination of a heating and a cooling mixer is preferably used. The heating or cooling mixers / hot air / air or water cooling are electrically heated independently as water / steam or thermal oil or. For the production of the modified organophilic clay material it is important that intensive fluidization of organophilic clay material and additive. When choosing the mixing unit this must be taken into account. The high shear mixing assembly is preferably selected from the group consisting of:

a) paddle mixers, eg plowshare mixers (Lödige high-speed mixer, Drais high-speed mixer, MTI turbine mixer) with what are known as single- or multiple crown tools;

b) screw mixers, such as screw mixers, which have a double screw which operates in either the same or opposite directions, segment screw mixers, such as co-axial kneader (Buss Co-kneader);

c) fluid mixers, eg impeller mixers, mechanical or pneumatic fluid mixers, eg Thyssen, Henschel, paper penmeier or MTI heating mixers, among other things

High-shear mixing assembly, a mechanical fluid mixer can be used, which operates on the fluidized bed principle.

It can be used for the intensive mixing and high shear mixing assemblies which have agitator and preferably at least one deflector. The stirrer systems are preferably made of stainless steel, in particular of martensitic steels, of RC40 and later hardened steels. Furthermore, they are preferably corrosion resistant. Ideally, the fluidizing blades inter alia with "Stellite K12" Hartmetallauf- welding at all relevant points armored. The distance of Bodenräumers the mixer base is preferably adjusted to a defined by the discharge material minimum distance and the other Fluidisierflügel and the horn tool arranged to that the Fluidisierflügeln at a selected fill level of high-speed mixer, the required temperatures can be reliably achieved.

In order to guarantee the necessary fluidization optimally, are minimal 1, preferably installed 2 or more deflector plates. These are arranged in a manner that the surface-modified organophilic clay material is optimally swirls.

The modified organophilic clay material obtained by the process according to the invention exhibits improved delamination on incorporation into polymers. In addition, these modified organophilic clay materials moreover exhibit better flow behavior and permit easier metering during processing of plastics in an extruder.

The invention therefore also provides a modified organophilic clay material, in particular surface-modified particulate organophilic clay material, which is obtainable by the method described above. The inventive method, the bulk density of the modified organophilic clay material according to the invention and the average particle size increases decreases. A characteristic of the inventive modified organophilic clay material is its improved delamination in polymers.

The inventive modified organophilic clay material performs well in polymer materials incorporated becoming almost completely delaminated (exfoliated). In this way, the inventive modified organophilic clay material can impart advantageous properties these polymeric materials, such as an increase in the fire resistance or scratch resistance of a polymer surface. Another object of the invention is therefore a polymeric composition which comprises the inventive modified organophilic clay material. As the polymer is in the polymer composition is preferably at least one polymer, which method is selected from the group which is formed from polyethylene and copolymers of ethylene lens, such as HDPE (high density polyethylene), MDPE (medium density polyethylene), LLDPE, VLDPE, LDPE (low density polyethylene), ULDPE, ethylene-hexene copolymers, ethylene-Qcten copolymers, isobutylene polymer, ethylene-propylene copolymers (EPM), terpolymers of ethylene-propylene-diene (EPDM), EBM (ethylene-butyl rubber ), EPDM, ethylene-vinyl silane 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 vinyl acetate), 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 terephthalates (PBT), polyester terephthalate (PET), fluorinated polymeric hydrocarbons, rubber, TPEs, block copolymers, TPU and polyurethane, 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 nano- componsit additive for a polymer composition.

Next, the invention comprises pre-exfoliated nanocomposite additives, which are obtainable by the novel process.

Another object of the invention is a nanocomposite composition, which is obtainable in a polymer composition by incorporating the nanocomposite additive according to the invention präexfolierten. The invention is further illustrated by way of examples and with reference to the accompanying figures. In which:

Fig. 1: a graph in which the temperature of the mixed material and the current consumption of the mixing assembly is indicated as a function of the mixing time;

FIG. 2 is a graph showing a particle size distribution of a commercially available organophilic clay material (Nanofil®^® 5; Suedchemie AG);

FIG. 3 is a graph showing a particle size distribution of an inventively modified organophilic clay material.

The mentioned in the examples, parameters were determined in the following manner:

Particle size distribution (Dso value):

The particle size distribution was determined by laser diffraction in a Mastersizer zer S (Malvern Instruments GmbH) determined in a range from 0.05 to 900 microns.

A sample of approximately 50 mg is placed in a 20 ml beaker with approximately 10 ml of ethanol and treated for 5 minutes using an ultrasound probe. The suspension is tikelgrößenanalysators transferred to the dispersing of the particle and as long as ethanol is added until the correct concentration of the sample is set on the meter. The measurement is performed according to the user. At the end of the measurement the result is saved and printed.

Bulk density:

A sample of air-dried material is aerated by shaking in a closed vessel, so that no mechanical parts are more compressed in the sample. A 100 ml measuring cylinder which is cut off at the 100 ml mark, is tared (ml) and then filled with the aid of a holder in a suspended powder funnel in about 20 seconds. After 2 minutes, the filling cone is withdrawn with a ruler. Thereafter, the weight (m2) of the full measuring cylinder 0.01 g is accurately determined.

Bulk density (g / 1) = (m2 - ml) x 10

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

Examples

Example 1 (Comparative)

100 g of a highly swellable n, natural sodium bentonite are dispersed hochscherend = 30 ° C in water at a temperature of T. The solids concentration of the sodium bentonite in water is 3%. The temperature of the bentonite suspension is increased to 70 ° C and a pre-dispersed mixture consisting of 90 mmol of distearyldimethylammonium chloride, 14 g of rapeseed oil methyl ester (Kebonal^® vent 20, Fa. Kebo) and 6.16 g polydiethylsiloxane (Litsol-^® PL, Fa. Kebo) added.

Once the abovementioned mixture of sodium bentonite flocculates the resultant organophilic bentonite and is filtered and spray-dried. The powder obtained has a bulk density of 240 g / 1st

From a sample of the organophilic clay material, the particle size distribution was measured. The values ​​are summarized in Table 1 below. Table 1: Particle size distribution of the organophilic clay material from Example 1

<img id="imgf000025_0001" he="99" wi="40" file="imgf000025_0001.tif" img-format="tif" img-content="table" orientation="portrait" inline="no" /><img id="imgf000025_0002" he="99" wi="39" file="imgf000025_0002.tif" img-format="tif" img-content="table" orientation="portrait" inline="no" /><img id="imgf000025_0003" he="99" wi="39" file="imgf000025_0003.tif" img-format="tif" img-content="table" orientation="portrait" inline="no" /><img id="imgf000025_0004" he="99" wi="40" file="imgf000025_0004.tif" img-format="tif" img-content="table" orientation="portrait" inline="no" />

The particle size distribution is shown graphically in FIG. 2 The derived from this particle size distribution limits are summarized in Table la

Table la: limit values ​​for the particle size distribution

<img id="imgf000025_0005" he="48" wi="53" file="imgf000025_0005.tif" img-format="tif" img-content="table" orientation="portrait" inline="no" />

Example 2:

In a Heizkühlmischer, FM 200 - KM 1000 from Thyssen Henschel 100 kg of nanoclays "Nanofil®^® 5 "of the South Chemie AG presented with a bulk density of 240 g /. 1 nano- fil^® 5 is a modified with distearyldimethylammoniumchloride bentonite. The revolution speed of the mixer is set to 1360 rpm (revolutions per minute), and it is heated to a temperature of 45 ° C. At this temperature 10 kg of rapeseed oil methyl ester (Kebonal^® 20, Fa. Kebo) and 4.4 kg Polyethylsiloxan (Litsolvent^® PL, Fa. Kebo) are metered in in the stated sequence as additive over a period of about 30 s. To ensure a homogeneous mixing, the addition of the additives is carried out directly into the thrombus produced by the mixing tool. At the stated rotation of the reaction mixture is heated to the discharge temperature of 80 ° C.

The temperature profile during the mixing process is shown in the Figure 1, the further the profile of the current consumption of the mixer. It will be appreciated that for a linear increase in temperature of the mixture at the conditions chosen, by about 7.5 minutes, a considerable current consumption of the mixer is observed. To complete agglomeration of the powder, and thus to prevent turn eventually impaired dispersibility of the nanoclay in polymers, the mixing process is terminated at a temperature of 80 ° C and after 7.5 minutes.

There is obtained a surface modified by the two additives organophilic clay material, having a bulk density of 480 g / 1st The modified organophilic clay material is a fine powder before the 2wiedergegebenen in Table particle. The particle size distribution is also given graphically in FIG. 3 Table 2: Particle size distribution of the modified organophilic clay material from Example 1

<img id="imgf000027_0001" he="97" wi="41" file="imgf000027_0001.tif" img-format="tif" img-content="table" orientation="portrait" inline="no" /><img id="imgf000027_0002" he="97" wi="39" file="imgf000027_0002.tif" img-format="tif" img-content="table" orientation="portrait" inline="no" /><img id="imgf000027_0003" he="97" wi="39" file="imgf000027_0003.tif" img-format="tif" img-content="table" orientation="portrait" inline="no" /><img id="imgf000027_0004" he="97" wi="39" file="imgf000027_0004.tif" img-format="tif" img-content="table" orientation="portrait" inline="no" />

Determined from the particle size distribution limits are summarized in Table 2a.

Table 2a: limit values ​​for the particle size distribution

<img id="imgf000027_0005" he="48" wi="53" file="imgf000027_0005.tif" img-format="tif" img-content="table" orientation="portrait" inline="no" />

In a continuation of the mixing process at temperatures above 80 ° C to form agglomerates with a significant coarser particle size distribution, as shown in FIG. 3 The surface-modified organophilic clay material is cooled at a low speed to a temperature between 20 and 40 ° C. For this purpose, the heated to 80 ° C modified organophilic clay material is transferred to a second mixer, which includes a cooling device and in which the mix is ​​cooled to a temperature between 20 and 40 ° C.

The bulk density of the powder obtained is 480 g / 1st During the implementation of the experiment samples were taken at regular intervals, and determines the bulk density. The results are summarized in Table 3 below.

Tab. 3: change in bulk density during the modification

<img id="imgf000028_0001" he="30" wi="161" file="imgf000028_0001.tif" img-format="tif" img-content="table" orientation="portrait" inline="no" />

Table 3 shows that increasing the bulk density after about 4 minutes of mixing time, and enters after that a mixing time of 7 to 8 minutes, a significant increase in the bulk density. This corresponds to the time for which even an increase in the current consumption of the mixer is observed.

The comparison of the particle size distribution of the inventively modified organophilic clay material (Figure 3) to that used for the preparation as a starting material organophilic clay material Nanofil®^® 5 (Figure 2) shows that a finer particle size distribution can be achieved by the dry mixing process according to the invention.

The Dso values ​​obtained in Examples 1 and 2 organophilic clay materials are listed for comparison again in Table 4 below. Table 4: D₅₀Values ​​organophilic clays

<img id="imgf000029_0001" he="26" wi="78" file="imgf000029_0001.tif" img-format="tif" img-content="table" orientation="portrait" inline="no" />

Thus, following advantages are obtained by the surface modification according to the invention (Example 2):

Increasing the bulk density by 100%; Reducing the particle size;

Improvement of the mechanical properties of polypropylene, which could be detected by following incorporation of the organophilic clay materials from Example 1 and Example 2. FIG.

Example 3 Compounding

The data obtained from Example 1 and Example 2 organophilic clay materials are as follows in the blow molding polypropylene Type RB 307 MO (producer: Borealis) compounded:

It is used a concurrent laboratory twin screw extruder Type ZE 25 (Berstorff). The dosage of all formulation components are gravimetrically into the main hopper. The emerging Compound strands are cooled in a water bath and granulated.

It is extruded in one 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 / h.

Specimens on an injection molding machine of the type Ergotech 100 / 420-310 (Demag) were prepared from the resulting granules. With the specimens obtained the modulus of elasticity (E_t) According to ISO 527-2 / 1A / 50 and the notched impact strength (Charpy) to ISO 179 / 1EU determined at 23 ° C. The values ​​found are given in Table 5 below.

Table 5: Properties of test specimens

<img id="imgf000030_0001" he="31" wi="168" file="imgf000030_0001.tif" img-format="tif" img-content="table" orientation="portrait" inline="no" />

As seen in Table 5, were obtained with the additive of Example 2 improved properties in terms of modulus and impact strength.

example 3

Example 2 was repeated except that the mixture of the organophilic clay material has not been carried out with the additive using a heating-cooling mixer but using an intensive mixer Eirich omitting the supply of heat during the mixing process. In the mixing tank the components were Nanofil 5 (1 kg), Kebonal 20 (100 g) and Lithosolvent PL submitted (44 g). The container was placed in the mixer and starts Wirbier and rotating plates.

Batch size: ca,

Wirblerantrieb: Level 2

Turntable drive: level 2

Bulk weight Nanofil®^® 5: 243 g / 1

During the mixing process, the temperature of the mix, and the current consumption of the mixer was regularly determined. Further samples were taken at regular intervals and Bulk density is determined. The values ​​are summarized in Table 6 assembled.

Table 6: Process parameters using an intensive mixer

<img id="imgf000031_0001" he="112" wi="110" file="imgf000031_0001.tif" img-format="tif" img-content="table" orientation="portrait" inline="no" />

Further, the particle size distribution of the starting material and the resulting product was measured and the Dso value. The results are summarized in Table 7 zusa.

Table 7: Dso value in mixing in an intensive mixer.

<img id="imgf000031_0002" he="20" wi="60" file="imgf000031_0002.tif" img-format="tif" img-content="table" orientation="portrait" inline="no" />

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