WO2008074705A1

WO2008074705A1 - Anisotropic cellular elastomers

Info

Publication number: WO2008074705A1
Application number: PCT/EP2007/063748
Authority: WO
Inventors: Gitta Egbers; Maximilian RÜLLMANN; Johann-Diedrich Brand; Manja Nürnberger; Steffen Mayer; Claus Gabriel
Original assignee: Basf Se
Priority date: 2006-12-20
Filing date: 2007-12-12
Publication date: 2008-06-26
Also published as: DE112007002776A5

Abstract

The present invention relates to cellular elastomers, wherein the cellular elastomer comprises magnetizable particles, which have a chain-shaped orientation parallel to one another. In addition, the invention relates to a method for producing cellular elastomers, preferably cellular polyurethane elastomers, with cellular polyurethane elastomers having a density according to DIN EN ISO 845 between 200 kg/m3 and 5000 kg/m3 (wherein the weight of said magnetizable particles is taken into consideration) being particularly preferred. The cellular elastomers are produced in the presence of magnetizable particles such that said magnetizable particles are present in the cellular elastomer. The production of the cellular elastomers is carried out in the presence of a preferably artificial magnetic field, which has a flux density of greater than 0.01 tesla, preferably a flux density of between 0.05 and 2 tesla. In addition, the present invention relates to cellular elastomers obtained in this way, particularly shoe soles comprising the inventive cellular elastomers.

Description

Anisotropic cellular elastomers

description

The present invention relates to cellular elastomers wherein the cellular elastomer contains magnetizable particles having a chain-like orientation parallel to each other. In addition, the invention relates to processes for the preparation of cellular elastomers, preferably cellular polyurethane elastomers, more preferably cellular polyurethane elastomers having a density according to DIN EN ISO 845 between 200 kg / m ³ and 5000 kg / m ³ (taking into account the weight of ug magnetizable particles wherein the cellular elastomers are prepared in the presence of magnetizable particles so that these magnetizable particles are present in the cellular elastomer, and the preparation of the cellular elastomers is carried out in the presence of a preferably artificial magnetic field having a flux density greater than 0, 01 Tesla, preferably with a flux density between 0.05 and 2 Tesla. Moreover, the present invention relates to cellular elastomers obtainable in this way, in particular shoe soles comprising the cellular elastomers according to the invention.

Further embodiments of the present invention can be taken from the claims, the description and the examples. It is understood that the features mentioned above and those yet to be explained of the subject matter according to the invention can be used not only in the particular combination specified, but also in other combinations, without departing from the scope of the invention.

Cellular, for example, microcellular polyisocyanate polyaddition products, usually polyurethanes and / or polyisocyanurates, which may optionally contain urea structures and are obtainable by reacting isocyanates with isocyanate-reactive compounds and processes for their preparation are generally known.

A particular embodiment of these products are cellular, in particular microcellular polyurethane elastomers, which differ from conventional polyurethane foams by their substantially higher density of usually 150 to 700 kg / m ³ , their particular physical properties and the possible applications thereof. Frequently, these cellular polyurethane elastomers are used in the form of foams having a compact surface and a cellular core, so-called polyurethane integral flexible foam elastomers. Such integral foams are used, for example, as a shoe sole, for example for street shoes, sports shoes, sandals and boots. In this case, the polyurethane soft integral foam elastomer can be used as an outsole, as a midsole and for decorative parts. Known shoe soles have a constant cushioning over the entire sole surface. For optimal biomechanical performance of the soles, to increase comfort and to prevent injuries, locally varying compression stiffness is desirable. For example, in the area of the forefoot the sole could be harder, softer in the heel area. Such a local variation of the compressive stiffness is currently only possible by means of relatively complicated processes, the formulation of the elastomer, preferably of the polyurethane system, being varied during the production of the sole. However, this requires a very high expenditure on equipment and is therefore uneconomical.

For the production of cellular elastomeric shoe soles, preferably polyurethane soles, for organizational reasons, in many cases the same starting material, for example the same polyurethane system, is used to manufacture soles for different shoe sizes. For larger shoe sizes, the body weight of the wearer is usually greater than for smaller shoe sizes. Here a greater compression stiffness of the sole would be desirable. This would also be possible only by using different formulations for the cellular elastomer, for example, different polyurethane systems, for different shoe sizes. This would only be possible with increased effort.

It was therefore an object of the invention to develop cellular elastomers, preferably cellular polyisocyanate polyaddition products, more preferably cellular polyurethane elastomers, in particular polyurethane integral flexible foams, which are obtained from a reaction mixture of constant composition, the compression stiffness being along one direction, namely Shoe soles in the vertical direction, can be adjusted.

A further object of the present invention is to develop cellular elastomers, preferably cellular polyisocyanate polyaddition products, more preferably cellular polyurethane elastomers, in particular intractable polyurethane flexible foams, different compression stiffness and / or elasticity along one direction in different local regions of a cellular elastomer Shoe soles in the vertical direction, can be adjusted.

These objects could be achieved by cellular elastomers containing magnetizable particles, wherein the magnetizable particles have a chain-like orientation parallel to each other.

Suitable cellular elastomers are generally known elastomers which can be prepared in the presence of magnetizable particles, for example elastomers based on ethylene vinyl acetate or polyisocyanate Polyaddition. As already indicated, elastomers based on polyisocyanate polyaddition products are preferred.

Such elastomers are generally known and widely described without the aligned magnetizable particles. The elastomers are preferably microcellular elastomers based on polyisocyanate polyaddition products, preferably with cells having a diameter of 0.005 mm to 2 mm, particularly preferably 0.01 to 0.5 mm.

Elastomers according to the invention are preferably elastomers without external action, in particular already without the action of an artificial magnetic field, wherein the anisotropy is defined by the modulus of elasticity determined in a compression test based on DIN ISO 7743. in at least one of three orthogonal directions by a factor of 1, 5 is greater than in the other two spatial directions. The specimens were bonded according to Method B from DIN ISO 7743. Furthermore, the method for determining the anisotropy of the elastomers according to the invention differs from the method described in DIN ISO 7743 in that the printing properties were measured at a test speed of 30 mm / min instead of the specified in the standard 10 mm / min. Further, disks having a diameter of 9.6 mm and a height of 4.0 mm were used instead of the disks of 29 mm diameter and 12.5 mm height required in the standard for determining the anisotropy of the elastomers according to the invention. The pressure modulus of the elastomers of the invention was determined from the force-deflection curve at a given strain of 2% instead of the 10% and 20% requirements of DIN ISO 7743, respectively. The maximum deformation was 4%, instead of 25%.

The anisotropic properties or the adjustable compression stiffness and / or the modulus of elasticity of the cellular elastomers according to the invention are preferably produced by the fact that the cellular elastomer contains magnetisable particles, preferably magnetisable particles with ferromagnetic or ferrimagnetic properties, which in the elastomer at least partially in one ordered distribution. The magnetizable particles are preferably arranged in a chain, wherein the chains are arranged parallel to each other. The chains preferably run linearly, that is to say parallel to a spatial direction, or arcuately, for example U-shaped, particularly preferably linear. The magnetizable particles in the elastomer can be locally aligned differently strong. The local orientation in the elastomer can be determined, for example, by the ratio of the average particle spacing perpendicular to the chains to the average particle spacing along the chains, while the degree of filling is held fixed. The larger this ratio for a given degree of filling by magnetizable particles, the more pronounced is the local orientation. The chain-like arrangements of the magnetizable particles can be continuous throughout the entire body of the cellular elastomer be, but also shorter. Shorter chains result, for example, from interruptions due to the cellular structure.

Preferably, the magnetizable particles in the cellular polyurethane elastomer have a chain-like orientation along a spatial direction and are correspondingly anisotropically aligned. This chain alignment is the result of the action of a magnetic field on the magnetizable particles during the preparation of the cellular elastomer and the fixation of this orientation by the curing of the cellular elastomer. The term chain-like orientation is to be understood as meaning that the magnetizable particles are arranged in juxtaposition. The strands (chains) traverse the material along a spatial direction, namely along the spatial direction in which the material has the higher modulus of elasticity. There are preferably several parallel juxtapositions. The mean distance of the juxtapositions becomes smaller as the degree of filling by magnetizable particles increases.

The cellular elastomer preferably contains between 1 and 95% by weight, preferably between 10 and 75% by weight, particularly preferably between 10 and 40% by weight of magnetizable particles, based on the total weight of the cellular elastomer containing the magnetisable particles.

The incorporation of magnetizable particles in cellular elastomers is known from WO 2006/007882, wherein the magnetizable particles are present disordered in the cellular elastomer. The isotropic or anisotropic incorporation of magnetic particles into compact elastomers is known from US Pat. No. 6,476,113 B1, US Pat

US 2005/01 16194 A1 or WO 2006/024457 A1. As magnetizable particles, it is possible to use all magnetisable particles, as described, for example, in the abovementioned publications. Preferably used magnetizable particles are described below under (f).

Cellular elastomers and their preparation are well known and widely described. Thus, the production of cellular elastomers based on polyisocyanate polyaddition products, for example, in EP-A 62 835, EP-A 36 994, EP-A 250 969, DE-A 195 48 770 and DE-A 195 48 771, as well as in EP897402 DE10227187, DE10227186 or DE10227185. Elastomers based on polyisocyanate polyaddition products having a compact surface and a cellular core, so-called flexible polyurethane integral foam elastomers, are particularly preferably used.

Polyurethane integral foam elastomers with a cellular core and a compact surface, also referred to below as integral polyurethane foams, are polyurethane foams according to DIN 7726 with a marginal zone which, due to the shaping process, has a higher density than the core. The above The total raw density of polyurethane integral foams according to the invention, averaged over the core and the edge zone, is preferably in the range from 150 kg / m ³ to 5000 kg / m ³ , more preferably from 200 to 2000 kg / m ³ and in particular from 200 to 1500 kg / m ³ Weight of the magnetizable particles is taken into account, that is, including the weight of the magnetizable or magnetic particles.

The process according to the invention for the preparation of anisotropic cellular elastomers, preferably cellular polyurethane elastomers, is characterized in that the cellular elastomers are prepared in the presence of magnetizable particles so that these magnetizable particles are present in the cellular elastomer, and the preparation of the cellular elastomers in the presence of a magnetic field having a flux density greater than 0.01 Tesla, preferably between 0.05 and 2 Tesla. Preferably, an elastomer of the invention has a density according to DIN EN ISO 845 between 150 kg / m ³ and 5000 kg / m ^{3 more} preferably from 200 to 2000 kg / m ³ and in particular from 200 to 1500 kg / m ³ , wherein the weight of magnetizable particles, that is inclusive of the weight of the magnetizable or magnetic particles.

In this case, the preparation is preferably carried out in a mold. It is particularly preferred to prepare cellular polyurethane elastomers of the invention in a form by reacting (B) isocyanates with (A) isocyanate-reactive compounds, wherein in at least one of the starting components, i. (A) and / or (B), magnetizable particles are contained.

In this case, the volume of the mold is at least partially filled by a magnetic field whose field lines are arcuate, for example U-shaped, or preferably parallel to the spatial direction in which the cellular elastomer is to have a greater modulus of elasticity. The magnetic field can be generated by means of permanent magnets and / or electromagnets. The preparation of compact elastomers in the presence of a magnetic field is described in [Ginder et al., Magnetorheological Elastomers: Properties and Applications, SPIE Vol. 3675, pp131] of WO 2006/024457 and in US 2005/01 16194 A1. If the flux density is different within the mold, elastomers having locally different properties, such as Young's modulus, are obtained without varying the starting material.

When the magnetic field is generated by means of permanent magnets, two permanent magnets are preferably arranged such that the north pole of one magnet and the south pole of the other magnet face the mold interior. The magnets are preferably in the mold walls or outside the mold walls. Suitable materials for the permanent magnets are all ferromagnetic or ferrimagnetic substances, preferably ferromagnetic metals, particularly preferably neodymium-iron-boron compounds which have a particularly high permeability. allow magnetization. Such magnets are available for example from the Internet supermagnete.de. The permanent magnets are either already in the mold walls or outside the mold walls before filling the mold or they are brought into their positions only after the filling of the mold, but before the solidification has progressed significantly.

When electromagnets are used, usually a yoke made of ferromagnetic or ferromagnetic material, preferably soft magnetic iron, is wound around by an electrical conductor. The yoke serves to increase the magnetic flux density and to conduct the magnetic field. The pole shoes of the yoke are embedded in the walls of the mold or are outside the mold and the mold therebetween in the magnetic field filled space. The magnetic field generated by the electromagnet is switched on either before the filling of the mold or preferably after filling, but before the solidification has progressed significantly. Another way to generate the magnetic field is the combination of permanent and electromagnets. The field of permanent magnets may be compensated by an electromagnet to provide a field-free state, e.g. When filling the mold to achieve, on the other hand, the field of the permanent magnets can be amplified by the electromagnet in order to achieve the required magnetic flux densities, especially for large cross sections of the cellular elastomer in the direction of the magnetic field lines.

A special embodiment of the combination of shape / magnet consists of a magnet assembly (electric or permanent magnet or combination of both) in the region of a mold-filling device (eg mixing head) and a clocking line or a carousel of molds which are exposed one after the other to the magnetic field ,

The design of the permanent magnets or of the electromagnets can preferably be adapted to the desired geometry of the cellular elastomer and the desired mechanical properties.

The magnetic field is preferably maintained at least until the elastomer has cured sufficiently far and the magnetizable particles are fixed in their arrangement.

As the material of the mold, a non-magnetic material such as aluminum can be selected so as not to disturb the magnetic field generated by the permanent magnets and / or electromagnets, on the other hand, at least in some areas, a magnetic material can be selectively used to generate the magnetic field through the permanent magnets and / or electromagnets, in an optimal way to influence.

The preparation of the cellular polyurethane shaped bodies according to the invention, in particular of the cellular integral polyurethane foams, is preferably carried out by (a) organic polyisocyanates with (b) at least one higher molecular weight compound having at least two reactive hydrogen atoms, (c) chain extenders and / or crosslinking agents, (d) blowing agents, (e) catalysts, (f) magnetizable particles and (g) optionally other auxiliaries and / or additives are mixed, placed in a mold and cured under the action of a magnetic field. The isocyanates (B) comprise the organic polyisocyanates (a) and the isocyanate-reactive compounds (A) at least the compound (b).

The organic and / or modified polyisocyanates (a) used for producing the polyurethane moldings according to the invention comprise the aliphatic, cycloaliphatic and aromatic di- or polyfunctional isocyanates known from the prior art (constituent a-1) and also any desired mixtures thereof. Examples are ^{4,4-diphenylmethane} diisocyanate, ^{2,4'-diphenylmethane} diisocyanate, the mixtures of monomeric diphenylmethane diisocyanates and higher-nuclear homologues gene of diphenylmethane diisocyanate (polymeric MDI), tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 2, 4- or 2,6-toluene diisocyanate (TDI) or mixtures of said isocyanates.

Preferably, 4,4'-MDI is used. The preferred 4,4'-MDI can contain from 0 to 20% by weight of 2,4'-MDI and small amounts, to about 10% by weight, of allophanate- or uro-amino-modified polyisocyanates. It is also possible to use small amounts of polyphenylene polymethylene polyisocyanate (polymeric MDI). The total amount of these high-functionality polyisocyanates should not exceed 5% by weight of the isocyanate used.

The polyisocyanate component (a) is preferably used in the form of polyisocyanate prepolymers. These polyisocyanate prepolymers are obtainable by reacting the above-described polyisocyanates (a-1) in excess, for example at temperatures of 30 to 100 ^° C., preferably at about 80 ^° C., with polyols (a-2) to give the prepolymer. For the preparation of the prepolymers of the invention, 4,4'-MDI is preferably used together with uretonimine-modified MDI and commercially available polyols based on polyesters, for example starting from adipic acid, or polyethers, for example starting from ethylene oxide and / or propylene oxide.

Polyols (a-2) are known to the person skilled in the art and described, for example, in "Kunststoffhandbuch, Volume 7, Polyurethanes", Carl Hanser Verlag, 3rd edition 1993, Chapter 3.1.

Ether-based prepolymers are preferably obtained by reacting polyisocyanates (a-1), more preferably 4,4'-MDI, with 2- to 3-functional polyoxypropylene and / or polyoxypropylene-polyoxyethylene polyols. Their production takes place usually by the well-known basic catalyzed addition of propylene oxide alone or in admixture with ethylene oxide to H-functional, in particular OH-functional starter substances. Examples of starter substances used are water, ethylene glycol or propylene glycol or glycerol or trimethylolpropane. Furthermore, as catalysts it is also possible to use multimetal cyanide compounds, so-called DMC catalysts. For example, as component (a-2), polyethers can be used, as described below under (b).

When using ethylene oxide / propylene oxide mixtures, the ethylene oxide is preferably used in an amount of 10-50% by weight, based on the total amount of alkylene oxide. The incorporation of the alkylene oxides can be carried out in blocks or as a random mixture. Particularly preferred is the incorporation of an ethylene oxide end block ("EO cap") to increase the content of more reactive primary OH end groups. The number average molecular weight of the polyols (a-2) is preferably between 1750 and 4500 g / mol.

If appropriate, customary chain extenders or crosslinking agents are added to the said polyols in the preparation of the isocyanate prepolymers. Such substances are described below under (c). Particular preference is given to using dipropylene glycol or tripropylene glycol as chain extender or crosslinking agent.

Higher molecular weight compounds (b) having at least two isocyanate-reactive hydrogen atoms may be, for example, polyetherols or polyesterols.

Polyetherols are prepared by known processes, for example by anionic polymerization with alkali metal hydroxides or alkali metal alkoxides as catalysts and with the addition of at least one starter molecule containing 2 to 3 reactive hydrogen atoms bonded, or by cationic polymerization with Lewis acids such as antimony pentachloride or borofluoride etherate from a or more alkylene oxides having 2 to 4 carbon atoms in the alkylene radical. Suitable alkylene oxides are, for example, tetrahydrofuran, 1, 3-propylene oxide, 1, 2 or 2,3-butylene oxide and preferably ethylene oxide and 1, 2-propylene oxide. Further, as catalysts, it is also possible to use multimetal cyanide compounds, so-called DMC catalysts. The alkylene oxides can be used individually, alternately one after another or as mixtures. Preference is given to mixtures of 1, 2-propylene oxide and ethylene oxide, wherein the ethylene oxide is used in amounts of 10 to 50% as ethylene oxide endblock ("EO-cap"), so that the resulting polyols have more than 70% of primary OH end groups , Suitable starter molecule are water or dihydric and trihydric alcohols, such as ethylene glycol, 1, 2- and 1, 3-propanediol, diethylene glycol, dipropylene glycol, 1, 4-butanediol, glycerol or trimethylolpropane into consideration.

The polyether polyols, preferably polyoxypropylene polyoxyethylene polyols, have a functionality of from 2 to 3 and molecular weights of from 1,000 to 8,000, preferably from 2,000 to 6,000 g / mol.

Polyester polyols may be prepared, for example, from organic dicarboxylic acids having 2 to 12 carbon atoms, preferably aliphatic dicarboxylic acids having 4 to 6 carbon atoms, polyhydric alcohols, preferably diols having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms. Suitable dicarboxylic acids are, for example: succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid and terephthalic acid. The dicarboxylic acids can be used both individually and in admixture with each other. Instead of the free dicarboxylic acids, the corresponding dicarboxylic acid derivatives, e.g. Dicarboxylic acid esters of alcohols having 1 to 4 carbon atoms or dicarboxylic anhydrides are used. Dicarboxylic acid mixtures of succinic, glutaric and adipic acid in ratios of, for example, from 20 to 35:35 to 50:20 to 32 parts by weight, and in particular adipic acid, are preferably used. Examples of dihydric and polyhydric alcohols, especially diols, are: ethanediol, diethylene glycol, 1,2- or 1,3-propanediol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1, 10 -Decandiol, glycerol and trimethylolpropane. Preferably used are ethanediol, diethylene glycol, 1, 4-butanediol, 1, 5-pentanediol and 1, 6-hexanediol. Polyester polyols may also be employed from lactones, e.g. ε-caprolactone or hydroxycarboxylic acids, e.g. ω-hydroxycaproic acid.

For the preparation of the polyester polyols, the organic, for example aromatic and preferably aliphatic polycarboxylic acids and / or derivatives and polyhydric alcohols catalyst-free or preferably in the presence of esterification catalysts, conveniently in an atmosphere of inert gas, such as nitrogen, carbon monoxide, helium, argon, inter alia the melt at temperatures of 150 to 250 ⁰ C, preferably 180 to 220 ⁰ C, optionally under reduced pressure, to the desired acid number, which is preferably less than 10, more preferably less than 2, polycondensed. According to a preferred embodiment, the esterification mixture at the abovementioned temperatures up to an acid number of 80 to 30, preferably 40 to 30, under normal pressure and then under a pressure of less than 500 mbar, preferably 50 to 150 mbar, polycondensed. Examples of esterification catalysts are iron, cadmium, cobalt,

Lead, zinc, antimony, magnesium, titanium and tin catalysts in the form of metals, metal oxides or metal salts into consideration. However, polycondensation can also be done in liquid phase in the presence of diluents and / or entrainers, such as benzene, toluene, xylene or chlorobenzene for the azeotropic distillation of the condensation water are performed. For the preparation of the polyester polyols, the organic polycarboxylic acids and / or derivatives and polyhydric alcohols are advantageously polycondensed in a molar ratio of 1: 1 to 1.8, preferably 1: 1, 05 to 1.2.

The polyesterpolyols obtained preferably have a functionality of 2 to 4, in particular of 2 to 3, and a molecular weight of 480 to 3000, preferably 1000 to 3000 g / mol.

Preferably used as relatively high molecular weight compound (b) are mixtures containing polyetherols and polyesterols.

Also suitable as polyols are polymer-modified polyols, preferably polymer-modified polyesterols or polyetherols, particularly preferably graft polyether or graft polyesterols, in particular graft polyetherols. This is a so-called polymer polyol, which usually has a content of, preferably thermoplastic, polymers of 5 to 60 wt .-%, preferably 10 to 55 wt .-%, more preferably 30 to 55 wt .-% and in particular 40 to 50 wt .-%, having. These polymer polyesterols are described, for example, in WO 05/098763 and EP-A-250 351 and are usually prepared by free-radical polymerization of suitable olefinic monomers, for example styrene, acrylonitrile, (meth) acrylates, (meth) acrylic acid and / or acrylamide Polyol ester serving graft base prepared. The side chains are generally formed by transferring the radicals from growing polymer chains to polyesterols or polyetherols. In addition to the graft copolymers, the polymer polyol predominantly contains the homopolymers of the olefins dispersed in unchanged polyesterol or polyetherol. In a preferred embodiment, the monomers used are acrylonitrile, styrene, acrylonitrile and styrene, particularly preferably exclusively styrene. If appropriate, the monomers are polymerized in the presence of further monomers, a macromer, a moderator and using a free-radical initiator, usually azo or peroxide compounds, in a polyesterol or polyetherol as the continuous phase. This process is described, for example, in DE 1 11 394, US Pat. No. 3,304,273, US Pat. No. 3,383,351, US Pat. No. 3,523,093, DE 1 152 536 and DE 1 152 537.

During radical polymerization, the macromers are incorporated into the copolymer chain. This forms block copolymers with a polyester or polyether and a poly-acrylonitrile-styrene block which act as phase mediators in the interface of continuous phase and dispersed phase and suppress the agglomeration of the polymer polyesterol particles. The proportion of macromers usually carries 1 to 20 wt .-%, based on the total weight of the monomers used to prepare the polymer polyol.

If polymer polyol is present in the relatively high molecular weight compound (b), this is preferably present together with other polyols, for example polyetherols, polyesterols or mixtures of polyetherols and polyesterols. Particularly preferably, the proportion of polymer polyol is greater than 5 wt .-%, based on the total weight of component (b). The polymer polyols may be contained, for example, based on the total weight of component (b) in an amount of 7 to 90 wt .-%, or from 11 to 80 wt .-%. The polymer polyol is particularly preferably polymer polyesterol or polymer polyetherol.

As chain extenders and / or crosslinking agents (c) are substances having a molecular weight of preferably less than 500 g / mol, more preferably from 60 to 400 g / mol used, wherein chain extenders have 2 isocyanate-reactive hydrogen atoms and crosslinking agent 3 to isocyanate-reactive hydrogen atoms. These can be used individually or preferably in the form of mixtures. Preference is given to using diols and / or triols having molecular weights of less than 400, more preferably from 60 to 300 and in particular from 60 to 150. Suitable examples are aliphatic, cycloaliphatic and / or araliphatic diols having 2 to 14, preferably 2 to 10 carbon atoms, such as ethylene glycol, 1, 3-propanediol, 1, 10-decanediol, 1, 2, 1, 3, 1, 4-Dihydroxycyclohexane, diethylene glycol, dipropylene glycol and preferably 1,4-butanediol, 1,6-hexanediol and bis (2-hydroxyethyl) hydroquinone, triols such as 1,2,4-, 1,3,5-trihydroxycyclohexane , Glycerin and trimethylolpropane, and low molecular weight hydroxyl-containing polyalkylene noxides based on ethylene and / or 1, 2-propylene oxide and the aforementioned diols and / or triols as starter molecules. Particularly preferred chain extenders ^) monoethylene glycol, 1, 4-butanediol and / or glycerol are used.

If chain extenders, crosslinking agents or mixtures thereof are used, these are expediently used in amounts of from 1 to 60% by weight, preferably from 1.5 to 50% by weight and in particular from 2 to 40% by weight, based on the weight of the components (b) and (c) are used.

Furthermore, blowing agents (d) are present in the production of polyurethane foams. These blowing agents optionally contain water (referred to as component (d-1)). In addition to water (d-1), additionally generally known chemically and / or physically active compounds can be used as propellant (d) (the further chemical propellants being component (d-2) and the physical propellant being component (i.e. -3). Chemical blowing agents are compounds which form gaseous products by reaction with isocyanate, such as, for example, water or formic acid. Under physical blowing agents One understands compounds which are dissolved or emulsified in the starting materials of polyurethane production and evaporate under the conditions of polyurethane formation. These are, for example, hydrocarbons, halogenated hydrocarbons, and other compounds, such as perfluorinated alkanes such as perfluorohexane, chlorofluorocarbons, and ethers, esters, ketones and / or acetals, for example (cyclo) aliphatic hydrocarbons having 4 to 8 carbon atoms, or hydrofluorocarbons as Solkane ^® 365 mfc from Solvay Fluorides LLC. In a preferred embodiment, the blowing agent employed is a mixture containing at least one of these blowing agents and water, in particular water as the sole blowing agent. If no water is used as blowing agent, preferably only physical blowing agents are used.

The content of (d-1) water in a preferred embodiment is from 0.1 to 2 wt .-%, preferably 0.2 to 1, 5 wt .-%, particularly preferably 0.3 to 1, 2 wt. %, in particular 0.4 to 1 wt .-%, based on the total weight of components (a) to (g), without consideration of the magnetizable particles (f).

In a further preferred embodiment, the reaction of the components (a), (b) and optionally (d) as an additional propellant hollow microspheres containing physical blowing agent added. The hollow microspheres can also be used in admixture with the abovementioned additional chemical blowing agents (d-2) and / or physical blowing agents (d-3).

The hollow microspheres usually consist of a shell of thermoplastic polymer and are filled in the core with a liquid, low-boiling substance based on alkanes. The production of such hollow microspheres is described, for example, in US Pat. No. 3,615,972. The hollow microspheres generally have a diameter of 5 to 50 microns. Examples of suitable hollow microspheres are available from Akzo Nobel under the trade name Expancell® ^®.

The hollow microspheres are generally added in an amount of 0.5 to 5 wt .-%, based on the total weight of components (b), (c) and (d).

As catalysts (e) for the preparation of the polyurethane foams, preference is given to using compounds which greatly accelerate the reaction of the hydroxyl-containing compounds of component (b) and optionally (c) with the organic, optionally modified polyisocyanates (a). Examples which may be mentioned are amidines, such as 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine, tertiary amines, such as triethylamine, tributylamine, dimethylbenzylamine, N-methyl-, N-ethyl-, N-cyclohexylmorpholine, N, N, N ', N'-tetramethylethylenediamine, N, N, N', N'-tetramethylbutanediamine, N, N, N ', N'-tetramethylhexanediamine, pentamethyldiethylenetriamine, tetramethyldiminoethyl ether, bis (dimethylaminopropyl ) urea, dimethylpiperazine, 1, 2 Dimethylimidazole, 1-azabicyclo- (3,3,0) -octane and preferably 1,4-diaza-bicyclo- (2,2,2) -octane and alkanolamine compounds such as triethanolamine, triisopropanolamine, N-methyl- and N- Ethyldiethanolamine and dimethylethanolamine. Likewise suitable are organic metal compounds, preferably organic tin compounds, such as tin (II) salts of organic carboxylic acids, for example tin (II) acetate, tin (II) octoate, tin (II) ethyl hexoate and tin (II) laurate and the dialkyltin (IV) salts of organic carboxylic acids, for example dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate and dioctyltin diacetate, and bismuth carboxylates such as bismuth (III) neodecanoate, bismuth 2-ethylhexanoate and Bismuth octanoate or mixtures thereof. The organic metal compounds can be used alone or preferably in combination with strongly basic amines. When component (b) is an ester, it is preferred to use only amine catalysts.

Preference is given to using from 0.001 to 5% by weight, in particular from 0.05 to 2% by weight, of catalyst or catalyst combination, based on the weight of component (b).

As magnetizable particles (f), it is possible to use all known magnetizable particles. Such particles form their own magnetic field in an external magnetic field. These may also have their own magnetic field in a space free from external magnetic fields, but the own magnetic field is amplified by an external magnetic field. Preference is given to using ferromagnets or ferromagnets, particularly preferably soft-magnetic ferro- or ferrimagnetics. Such particles are described, for example, in WO 2006/007882, US Pat. No. 6,476,113 B1, US 2005/0116194 A1 or WO 2006/024457 A1.

Preferably, as materials for the magnetizable particles of the present invention, iron, cobalt, nickel, even in non-pure form, and alloys thereof, such as iron-cobalt, iron-nickel, magnetic steel, iron-silicon, and / or their mixtures, oxide ceramic materials, such as cubic ferrites, perovskites and garnets of the general formula MO-Fβ2θ3, where M is one or more metals selected from the group consisting of Mn, Fe, Co, Ni, Cu, Zn, Ti, Cd and Mg Mixed ferrites such as MnZn, NiZn, NiCo, NiCuCo, NiMg, CuMg ferrites and / or mixtures thereof, and particles of iron carbide, iron nitride, alloys of vanadium, tungsten, copper and manganese and / or their Mixtures and magnetite (Fβ3θ4) used.

Particularly preferred magnetizable particles are iron powder, in particular finely divided iron powder and again preferably carbonyl iron powder, which is preferably prepared from iron pentacarbonyl, gas and / or water atomized iron powder, coated iron powder and mixtures of these iron powders with one another and mixtures of these iron powders with other magnetizable particles. puts. The magnetizable particles may preferably have a mean longest extent between 0.01 to 1000 microns.

The shape of the magnetizable particles may be uniform or irregular. For example, they can be spherical, rod-shaped or needle-shaped particles. Here, the spherical shape, d. H. the spherical shape or a shape similar to the spherical shape, especially preferred when high filling levels are desired.

When spherical particles are used, the average diameter [d ₅ o] is preferably 0.01 to 1000 μm, more preferably 0.1 to 100 μm, particularly 0.5 to 10 μm. The above-mentioned orders of magnitude for the average diameter are particularly advantageous for the preparation of the cellular elastomers according to the invention because they lead to a better redispersibility and better flowability of the PU components loaded with the particles.

If no spherical particles are used, the mean longest dimension of the magnetizable particles provided according to the invention is preferably 0.01 to 1000 μm, preferably 0.1 to 500 μm. If metal powder is used as the magnetizable particle, this can be obtained, for example, by reduction of corresponding metal oxides. Optionally, the reduction is followed by a sieving or milling process. Other ways to prepare correspondingly suitable metal powder is the electrolytic deposition or the production of metal powder via water or gas atomization. It is also possible to use mixtures of magnetizable particles. In particular, the size distribution of the magnetizable particles used can also be bimodal.

Preference is given to using from 1 to 95% by weight, preferably from 10 to 75% by weight, particularly preferably from 10 to 40% by weight, of magnetizable particles (f), based on the total weight of components (a) to (g).

Optionally, auxiliaries and / or additives (g) may also be added to the reaction mixture for the preparation of the polyurethane foams. Examples which may be mentioned are surface-active substances, foam stabilizers, cell regulators, release agents, rubber vulcanization assistants, fillers, dyes, pigments, hydrolysis protectants, odor-absorbing substances and fungistatic and / or bacteriostatic substances.

Suitable surface-active substances are, for example, compounds which serve to assist the homogenization of the starting materials and, if appropriate, are also suitable for regulating the cell structure. Examples which may be mentioned are emulsifiers, such as the sodium salts of castor oil sulfates or of fatty acids, and also salts of fatty acids with amines, for example diethylamine, stearic acid diethanolamine, ricinoleic diethanolamine, salts of sulfonic acids, for example alkali metal or ammonium salts of dodecylbenzene- or dinaphthylmethanedisulfonic acid, and ricinoleic acid; Foam stabilizers, such as siloxane-oxalkylene copolymers and other organopolysiloxanes, ethoxylated alkylphenols, ethoxylated fatty alcohols, paraffin oils, castor oil or ricinoleic acid esters, Turkish red oil and peanut oil, and cell regulators, such as paraffins, fatty alcohols and dimethylpolysiloxanes. To improve the emulsifying effect, the cell structure and / or stabilization of the foam, oligomeric acrylates having polyoxyalkylene and fluoroalkane radicals as side groups are also suitable. The surface-active substances are usually used in amounts of from 0.01 to 5 parts by weight, based on 100 parts by weight of component (b).

Examples of suitable release agents are: reaction products of fatty acid esters with polyisocyanates, salts of amino-containing polysiloxanes and fatty acids, salts of saturated or unsaturated (cyclo) aliphatic carboxylic acids having at least 8 carbon atoms and tertiary amines, and in particular internal release agents such as carboxylic esters and or amides prepared by esterification or amidation of a mixture of montanic acid and at least one aliphatic carboxylic acid having at least 10 carbon atoms with at least difunctional alkanolamines, polyols and / or polyamines having molecular weights of 60 to 400 g / mol, such as For example, in EP 153 639 discloses mixtures of organic amines, metal salts of stearic acid and organic mono- and / or dicarboxylic acids or their anhydrides, such as disclosed in DE-A-3,607,447, or mixtures of an imino compound, the metal salt of a carboxylic acid and optionally a carbon acid, such as for example in US 4,764,537 disclosed.

Rubber vulcanization aids are to be understood as the vulcanization auxiliaries customary for the vulcanization of rubber. Specific examples are: vulcanizing agents, such as sulfur, peroxides, metal oxides, activators, such as metal oxides, e.g. the combination of zinc oxide and stearic acid, accelerators such as thiorams, guanidines, thiazoles, sulfenamides and dithiocarbamates. These are described, for example, in P.A. Ciullo, "The rubber formulation", Hoyes Publications, 1999, ISBN: 0-8155-1434-4.

Fillers, in particular reinforcing fillers, are understood to be the conventional organic and inorganic fillers, reinforcing agents, weighting agents, coating compositions, etc., which are known per se. Specific examples are: inorganic fillers, such as silicate minerals, for example phyllosilicates, such as antigorite, bentonite, serpentine, hornblende, amphiboles, chrysotile and talc, metal oxides, such as kaolin, aluminas, titanium oxides, zinc oxide and iron oxides, metal salts such as chalk and barite, and inorganic pigments, such as cadmium sulphide, zinc sulphide and glass, etc. Preference is given to using kaolin (china clay), aluminum silicate and coprecipitates of barium sulphate and aluminum silicate, and also natural lhe and synthetic fibrous minerals, such as wollastonite, metal and in particular glass fibers of various lengths, which may optionally be sized. Suitable organic fillers are, for example, carbon black, melamine, rosin, cyclopentadienyl resins and graft polymers and also cellulose fibers, polyamide, polyacrylonitrile, polyurethane and polyester fibers based on aromatic and / or aliphatic dicarboxylic acid esters and in particular carbon fibers.

The inorganic and organic fillers can be used individually or as mixtures and are advantageously added to the reaction mixture in amounts of from 0.5 to 50% by weight, preferably from 1 to 40% by weight, based on the weight of the components (a) to (c), but the content of mats, nonwovens and woven fabrics of natural and synthetic fibers can reach values up to 80% by weight.

The components (a) to (g) are mixed together to produce a cellular polyurethane molded article according to the invention in amounts such that the equivalence ratio of NCO groups of the polyisocyanates (a) to the sum of the reactive hydrogen atoms of the components (b), (c) and ( c) 1: 0.8 to 1: 1, 25, preferably 1: 0.9 to 1: 1, 15. In the context of the invention, the mixture of components (a) to (g) at reaction conversions of less than 90%, based on the isocyanate groups, is referred to as the reaction mixture.

The polyurethane moldings according to the invention, in particular the integral polyurethane foams, are preferably prepared by the 2-step process. To this end, an isocyanate prepolymer is first prepared and this is then prepared with the components (b) to (g), if present, by means of the low-pressure technique in closed, suitably tempered molds, as described above. These procedures for the preparation of polyurethane elastomers without magnetizable particles (f) are described for example by Piechota and Röhr in "Integralschaumstoff ', Carl Hanser Verlag, Munich, Vienna, 1975, or in the" Plastics Handbook ", Volume 7, Polyurethanes, 3rd Edition, 1993, Chapter 7. This procedure can be applied analogously, with the mold, as described above, being filled with a magnetic field.

The starting components (a) to (g) are preferably mixed at a temperature of 15 to 90 ⁰ C, more preferably from 25 to 55 ⁰ C and introduced the reaction mixture optionally under elevated pressure in the closed mold. The mixing can be carried out mechanically by means of a stirrer or a stirring screw or under high pressure in the so-called countercurrent injection method. The mold temperature is expediently 20 to 160 ^° C., preferably 30 to 120 ^° C., particularly preferably 30 to 60 ^° C. The amount of the reaction mixture introduced into the mold is such that the resulting molded body has a density of 150 to 5000 kg / m ³ , in particular from 200 to 2000 kg / m ³ , wherein the mass of the magnetizable particles is taken into account. The degrees of densification for the preparation of the polyurethane integral foam are in the range from 1.1 to 8.5, preferably from 2.1 to 7.0.

An inventive polyurethane molded body, in particular a polyurethane integral foam is preferably used as a shoe sole, for example as a midsole or outsole, preferably as a midsole. In this case, for the production of the shoe of the polyurethane molded body according to the invention after its production on the shoe upper, for example by sewing or gluing, are attached.

If the polyurethane molded body according to the invention, in particular the polyurethane integral foam, used as a midsole, an outsole made of rubber is usually used. To produce the composite of outsole and midsole, the polyurethane molded article according to the invention is produced in a mold as described above, wherein a rubber sole is inserted into the mold before introduction of the polyurethane reaction mixture. After curing, a composite material, consisting of rubber outsole and inventive polyurethane molded body, are removed from the mold. Alternatively, a shoe according to the invention is produced by means of direct injection. In this case, the polyurethane reactive mixture is placed in a mold containing an outsole made of rubber and is completed by the shoe upper.

With the aid of the method according to the invention, it is possible, for example, starting from the same mixture for producing elastomers, preferably from the same polyurethane reaction mixture, to obtain shoe soles having different compression stiffnesses by applying a different strength magnetic field along the later loading direction during their production.

Furthermore, starting from the same mixture for producing elastomers, preferably from the same polyurethane reaction mixture, it is also possible to produce shoe soles which have a higher compression stiffness in the front sole area than in the heel area, by applying a stronger magnetic field along the later sole in the area of the front sole Loading direction applies as in the heel area.

In each case, the above-mentioned anisotropic mechanism is formed in the region of the magnetic field and the material is given a significantly higher compression rigidity in the direction of the magnetic field vector, ie for shoe soles in the vertical direction, and thus also a significantly greater compression stiffness than the regions of the sole used in the production were exposed to no or a lower magnetic field. A particular advantage of this method is that the mechanical properties can be adjusted continuously in a wide range depending on the strength of the magnetic field applied during the preparation, without the composition of the mixture for the preparation of the cellular elastomer according to the invention, preferably the polyurethane reaction mixture, must be changed. Furthermore, an elastomer according to the invention also exhibits anisotropy in the tensile modulus. The tensile modulus can be determined by the same method as the printing module, ie by the method described above in accordance with DIN ISO 7743. By virtue of the fact that the specimens are glued to the plates of the testing machine, tensile loads can also be applied. The anisotropy of an elastomer of the invention in the elongation is preferably 1, 3 and more.

At cyclic pressure or tensile loading of the elastomer according to the invention, a hysteresis behavior which is markedly more pronounced parallel to the direction of orientation of the iron particles than in a perpendicular orientation.

Further, an elastomer of the present invention exhibits magnetorheological properties, i. When a magnetic field is applied parallel to the orientation direction of the carbonyl iron particles and the magnetic field vector, the complex shear modulus, measured in oscillatory shear at frequencies between 0.1 and 10 Hz, increases. The orientation direction of the carbonyl iron particles corresponds to the direction of the shear gradient. The increase of the shear modulus is reversible, i. when the magnetic field is switched off, the module returns to its initial value.

Furthermore, an elastomer according to the invention exhibits a higher specific electrical conductivity parallel to the chain-like structures of the carbonyl iron particles than perpendicular thereto. Moreover, as the compression pressure increases, there is an increase in specific conductivity and, after passing through a maximum, a decrease again. This behavior is found both when measuring parallel and perpendicular to the orientation direction of the carbonyl iron particles. The increased specific conductivity parallel to the chain-like structures of the carbonyl iron particles, i. for shoe soles in the vertical direction, is favorable for safety shoes, for which an antistatic equipment is required.

The elastomer according to the invention preferably also exhibits anisotropy in the cell morphology in addition to the orientation of the iron particles in chain-like structures. The foam cells are also arranged in chain-like structures, that is, the cell walls, which are oriented parallel to the direction of the magnetic field applied in the preparation, form approximately continuous walls. The cell walls, which are oriented perpendicular to the direction of the magnetic field applied in the preparation, are arranged rather randomly. By the following examples, the invention will be explained in more detail.

Examples Example 1: Polyurethane shoe system with carbonyl iron powder

According to Table 1, a polyurethane molded foam was prepared at a mass ratio A: B of 100: 26.2. Thus, the molar ratio of isocyanate groups to isocyanate-reactive groups, including water, was 0.98, which corresponds to an isocyanate index of 98.

Table 1

Where:

Polyol: polyester polyol based on adipic acid, 1,4-butanediol, started with ethylene glycol

KV: monoethylene glycol

Stabilizer 1: Elastostab® H01 ^® (BASF) Stabilizer 2: Tegostab B8443 ^® (Degussa) Catalyst: amine catalyst Lupragen N 203 ^® (BASF) ISO 187/3 ^®: Isocyanate prepolymer from Elastogran based on 4,4 ^' -MDI, polyester polyols and optionally addition of low molecular weight diols, NCO content = 16.0%. Index: Ratio of isocyanate groups and reactive hydrogen atoms ^* 100 The amount of carbonyl iron powder used in Example 1 corresponds to an amount of iron of 39.6% by weight, based on the overall system. The carbonyl iron powder used was the EQ type from BASF Aktiengesellschaft with a mean diameter [dso] of 2.5 to 3.5 μm.

The carbonyl iron powder was mixed with the A component heated to 40 ^° C., and then the B component was mixed. The system was poured into the preheated to 40 ⁰ C mold. The mold with the system was then in the oven for 5 min. kept at 40 ⁰ C and then removed from the mold. The system weight was chosen to give a density of 850 kg / m ³ .

The mold allows the production of disc-shaped specimens with a diameter of 31 mm and a thickness of 10 mm. In the bottom and in the lid of the form cuboid permanent magnets are embedded. The magnets have a square base area of 4 by 4 cm ² . The distance between the magnets is 12 mm when the mold is closed and the resulting magnetic flux density in the intermediate space is approximately 0.6 Tesla (measured when the mold is empty). Apart from the magnets, the shape consists of non-magnetic metals.

The PU system was poured with the mold open on the bottom of the mold, behind which there is a magnet. Then the mold was collapsed, thus placing the second magnet in position and building up the magnetic field for aligning the iron particles along the disk axis.

The characterization of the finished samples with the scanning electron microscope clearly shows chain-like structures of the Carbonyleisenteilchen along the spatial direction in which the magnetic field lines were oriented. The printing modulus of the material produced in this way, determined on the basis of DIN ISO 7743 (the deviations from the methods described in the standard are explained above in the description), is 30 MPa along the orientation direction of the iron particles and 3.1 MPa in the two spatial directions perpendicular thereto , That in compression, the elastic modulus anisotropy is 30: 3.1 = 9.7.

Further properties of the elastomer according to Example 1:

The elastomer according to Example 1 also exhibits anisotropy in the tensile modulus. The tensile modulus can be determined by the same method as the pressure modulus, ie by the method described above in accordance with DIN ISO 7743. By virtue of the fact that the specimens are adhesively bonded to the plates of the testing machine also tensile loads are applied. The tensile modulus parallel to the orientation direction of the carbonyl iron particles is 14.3 MPa, perpendicular to the orientation direction 3.1 MPa. In other words, in tensile load, the anisotropy of the modulus of elasticity is 14.3: 3.1 = 4.6 and is thus smaller than under compressive load.

In the case of cyclic compression or tensile loading of the material, the hysteresis behavior is much more pronounced parallel to the orientation direction of the iron particles than in a perpendicular orientation. At a deformation rate of 30 mm / min and a maximum deformation of 4%, the dissipated energy per unit volume per parallel orientation loading and unloading cycle is 7226 J / m ³ in compression and 2935 J / m ³ in elongation. When oriented vertically, the dissipated energy per unit volume is 820 J / m ³ in compression and 1215 J / m ³ in elongation. The specimens were cylindrical, 4 mm high and 9.6 mm in diameter.

The elastomer of Example 1 exhibits magnetorheological properties, i. upon application of a magnetic field parallel to the orientation direction of the carbonyl iron particles and the magnetic field vector, the complex shear modulus, measured in oscillatory shear at frequencies between 0.1 and 10 Hz, increases. The orientation direction of the carbonyl iron particles corresponds to the direction of the shear gradient. The increase of the shear modulus is reversible, i. when the magnetic field is switched off, the module returns to its initial value. The magnitude of the relative magnetorheological effect in the storage modulus G 'is 7% at a shear frequency of 1 Hz and a shear amplitude of 0.1%. Megnetorheological effects in compact elastomers, so-called magnetorheological elastomers, and their measurement are described in e.g. in WO 2006/024457 A1.

The elastomer of Example 1 exhibits a higher specific electrical conductivity parallel to the chain-like structures of the carbonyl iron particles than perpendicular thereto. Moreover, as the compression pressure increases, there is an increase in specific conductivity and, after passing through a maximum, a decrease again. This behavior is found both when measured parallel and perpendicular to the direction of orientation of the carbonyl iron particles. The maximum in the pressure-dependent spec. Conductivity, measured at a voltage of U = 10 volts, for parallel orientation is approx. 1, 2 · 10 ^-6 S / cm and approx. 6 bar, for vertical orientation approx. 1, 8-10 ^"10 S / cm and about 5.5 bar.

The elastomer according to Example 1, in addition to the orientation of the iron particles in chain-like structures, also exhibits anisotropy in the cell morphology. The foam cells are also arranged in chain-like structures, that is, the cell walls, which are oriented parallel to the direction of the magnetic field applied in the preparation, form approximately continuous walls. The cell walls, which are oriented perpendicular to the direction of the magnetic field applied in the preparation, are arranged rather randomly. This anisotropy in cell morphology is due to the attributable to the magnetic field and the magnetizable particles caused flow processes in the foaming.

Non-inventive comparative examples:

Comparative Example 2: The preparation of the elastomer was carried out as in Example 1 with the exception that no carbonyl iron powder was used and that the curing took place without application of a magnetic field.

Comparative Example 3: The preparation of the elastomer was carried out as in Example 1 with the exception that no carbonyl iron powder was used. A magnetic field was applied as described in Example 1. Comparative Example 4 The preparation of the elastomer was carried out as in Example 1, except that the curing took place without application of a magnetic field.

The following table shows the mechanical anisotropy in compression of the materials according to Examples 1 to 4:

Only when using magnetizable particles and a magnetic field in the preparation to obtain the anisotropy in the printing module.

Claims

claims

1. Cellular elastomer, characterized in that the cellular elastomer contains magnetizable particles which have a chain-like orientation parallel to each other.

2. Cellular elastomer according to claim 1, characterized in that the chain-like orientation in the elastomer is pronounced to different degrees.

3. Cellular elastomer according to claim 1 or 2, characterized in that the chain-shaped alignment is linear or arcuate.

4. Cellular elastomer according to claim 3, characterized in that the chain-like orientation is linear.

5. Cellular elastomer according to one of claims 1 to 4, characterized in that it is a cellular polyurethane elastomer.

6. Cellular elastomer according to claim 5, characterized in that it is a Polyurethanintegalschaumstoff.

7. Cellular elastomer according to claim 5 or 6, characterized in that it is a cellular polyurethane elastomer having a density according to DIN EN ISO 845 between 150 and 5000 kg / m ³ , wherein the density refers to the total weight of the cellular polyurethane elastomer.

8. Cellular elastomer according to one of claims 1 to 7, characterized in that as magnetizable particles in the cellular elastomer iron powder, preferably carbonyl iron powder is included.

9. Cellular elastomer according to claim 8, characterized in that is contained as magnetizable particles in the cellular elastomer carbonyl iron powder.

10. Cellular elastomer according to one of claims 1 to 9, characterized in that the magnetizable particles have a spherical, rod-shaped or needle-shaped form.

1 1. A cellular elastomer according to any one of claims 1 to 10, characterized in that as magnetizable particles spherical particles in the cellular elastomer are present, which have a mean diameter [dso] between 0.01 to 1000 microns.

12. Cellular elastomer according to one of claims 1 to 11, characterized in that the magnetizable particles in the cellular elastomer are those which have a mean longest extent between 0.01 to 1000 microns.

13. Cellular elastomer according to one of claims 1 to 12, characterized in that the cellular elastomer contains between 1 and 95 wt .-% magnetizable particles, based on the total weight of the cellular elastomer containing the magnetizable particles.

14. A process for the preparation of cellular elastomers, characterized in that one prepares the cellular elastomers in the presence of magnetizable particles, so that these magnetizable particles are present in the cellular elastomer, and the preparation of the cellular elastomers in one

Performs magnetic field having a flux density greater than 0.01 Tesla.

15. The method according to claim 14, characterized in that the flux density of the magnetic field is locally different in the region in which the cellular elastomer is produced.

16. The method according to claim 14 or 15, characterized in that one prepares in a mold by reacting (a) isocyanates with (b) isocyanate-reactive compounds cellular polyurethane elastomers, wherein in at least one of the starting components containing magnetizable particles.

17. The method according to claim 16, characterized in that the cellular E-lastomer is an elastic polyurethane molded article with a compact surface and cellular core, wherein a) isocyanates with b) at least one higher molecular weight compound having at least two reactive hydrogen atoms, c) optionally chain extenders and f) magnetizable particles and g) optionally other auxiliaries and / or additives mixed into a reaction mixture, in a mold and under the action of a magnetic field having a flux density of greater than 0.01 Tesla has hardened to polyurethane molding.

18. The method according to claim 16 or 17, characterized in that the volume of the mold is filled by a magnetic field, whose field lines are parallel to the spatial direction, in which the cellular elastomer is to have a larger e- modulus of elasticity.

19. The method according to any one of claims 14 to 18, characterized in that as magnetizable particles are those based on iron powder, preferably carbonyl iron powder.

20. The method according to claim 19, characterized in that are included as magnetizable particles based on carbonyl iron powder.

21. The method according to any one of claims 14 to 20, characterized in that the magnetizable particles have a spherical, rod-shaped or needle-shaped form.

22. The method according to any one of claims 14 to 21, characterized in that are present as magnetizable particles spherical particles in the cellular E-lastomer having a mean diameter [dso] between 0.01 to

1000 μm.

23. The method according to any one of claims 14 to 22, characterized in that as magnetizable particles in the cellular elastomer those present gene having a mean longest extent between 0.01 to 1000 microns.

24. The method according to any one of claims 14 to 23, characterized in that the cellular elastomer contains between 1 and 95 wt .-% magnetizable particles, based on the total weight of the cellular Elstomers containing the magnetizable particles.

25. Cellular elastomer obtainable by a process according to any one of claims 14 to 24.

26. Shoe sole comprising a cellular elastomer according to one of claims 1 to 13 or 25.

27. Shoe sole according to claim 26, characterized in that it is a midsole or an outsole.