WO2001005883A1 - Compact and/or cellular polyurethane elastomers with nanoscale fillers - Google Patents

Abstract

The invention relates to compact and/or cellular polyurethane elastomers (PUR elastomers) with nanoscale fillers, and to methods for producing the same.

Description

Compact and / or cellular polyurethane elastomers with nanoscale fillers

The invention relates to compact and / or cellular polyurethane elastomers (PUR elastomers) with nanoscale fillers and processes for their production.

The production of compact or cellular, e.g. Microcellular, PUR elastomers have long been known from numerous patent and literature publications. An overview of PUR elastomers, their properties and applications is given e.g. B. in G.W. Becker, D. Braun (ed.): "Plastic manual",

Volume 7, 3rd edition, Carl-Hanser-Verlag, Munich, Vienna 1993, pp. 417-513.

It has now been found that compact or microcellular PUR elastomers with an improved property profile, in particular with high thermal stability in a dynamically resilient state, can be produced using nanoscale SiO ₂ . Even low levels of nanoparticles, for example 0.01 to 20% by weight (based on PUR elastomer), lead to a clear improvement in the property profile, in particular the high temperature resistance.

The invention relates to compact and / or cellular polyurethane elastomers which contain 0.01 to 20% by weight, preferably 0.2 to 10% by weight, of nanoscale SiO ₂ . The invention further relates to a method for producing such elastomers by reaction

a) a di- and / or polyisocyanate with b) higher molecular weight polyhydroxyl compounds, c) a nanoscale filler

and if necessary

d) low molecular weight chain extenders and / or crosslinking agents, e) catalysts, f) blowing agents and g) additives,

which is characterized in that the nanoscale filler used is nanoscale SiO 2 or a filler which is present as nanoscale SiO in the resulting PUR elastomer by using a suitable process.

The PUR elastomers are preferably produced by the prepolymer process, with a polyaddition adduct containing isocyanate groups advantageously being produced in the first step from the higher molecular weight polyhydroxy compound (b) and at least one di- or polyisocyanate (a). In the second step, massive PUR elastomers made from prepolymers containing such isocyanate groups can be reacted with low molecular weight chain extenders and / or crosslinking agents (d) and / or higher molecular weight ones

Polyhydroxyl compounds (b) can be produced. If water or mixtures of water and optionally low molecular weight chain extenders and / or crosslinking agents (d) and / or higher molecular weight polyhydroxyl compounds (b) are used in the second step, microcellular PUR elastomers can be produced in this way. Instead of water or preferably in combination with water, low-boiling liquids which evaporate under the influence of the exothermic polyaddition reaction and advantageously have a boiling point under atmospheric pressure in the range from -40 to 120 ° C., preferably from 10 to 90 ° C., or Gases can be used as physical blowing agents or chemical blowing agents.

Dispersions of the nanoscale filler (c) in protic or aprotic solvents, such as, for. B. water, methanol, ethanol, z ^' so-propanol, ethanediol, 1,4-butanediol, 1,6-hexanediol, THF, diethyl ether, pentane, cyclopentane, hexane, heptane, toluene, acetone, 2-butanone or dilute acids such as hydrochloric acid, sulfuric acid, acetic acid or phosphoric acid used and added to the higher molecular weight polyhydroxyl compound (b) and / or optionally to the low molecular weight chain extender and / or crosslinking agent (d). The solvent of the dispersion can then optionally be removed, for example distilled off.

Are dispersions of the nanoscale filler (c) in solvents which are inert towards NCO groups, e.g. Acetone, tetrahydrofuran, 1,4-dioxane, hydrocarbons such as e.g. Pentane, hexane, heptane, cyclohexane, toluene used, these can also be added to the polyisocyanate (a) and / or optionally the prepolymer containing isocyanate groups.

However, the nanoscale filler can also be used as a powder, in which the primary particles of the filler can also be agglomerated, in the di- and / or polyisocyanate (a) and / or in the higher molecular weight polyhydroxyl compound (b) and / or optionally in the low molecular chain extension and / or crosslinking agent (d) can be introduced. The shear forces that occur during the incorporation of the powder detach the primary particles from the nanoparticles present in the powder in agglomerated form, so that they are largely dispersed in the system component. If necessary, dispersing aids can also be used, e.g. in the article by P. Walstra: "Formation of Emulsions" in

"Encyclopedia of Emulsions Technology", vol. 1, Decker-Verlag, New York, Basel, 1983.

Suitable starting components a) for the process according to the invention are aliphatic, cycloaliphatic, aromatic and heterocyclic polyisocyanates, such as those e.g. by W. Siefken in Justus Liebigs Annalen der Chemie, 562, pages 75 to 136, for example those of the formula

Q (NCO) _n in which n = 2-4, preferably 2, and Q is an aliphatic hydrocarbon radical with 2-18, preferably 6-10 C atoms, a cycloaliphatic hydrocarbon radical with 4-15, preferably 5-10 C atoms, an aromatic hydrocarbon radical with 6 -15, preferably 6-13 C atoms, or an araliphatic hydrocarbon radical with 8-15, preferably 8-13 C atoms, for example ethylene diisocyanate,

1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), 1,12-dodecane diisocyanate, cyclobutane-l, 3-diisocyanate, cyclohexane-1,3- and -1,4-diisocyanate and any mixtures of these isomers, l- Isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (DE-AS 1 202 785, US Pat. No. 3,401,190), 2,4- and 2,6-hexahydrotoluenediisocyanate and any mixtures of these isomers,

Hexahydro-1,3- and -1,4-phenylene diisocyanate, perhydro-2,4'- and -4,4'-diphenylmethane diisocyanate, 1,3- and 1,4-phenylene diisocyanate (DE-OS 196 27 907), 1,4-durol diisocyanate (DDI), 4,4'-stilbene diisocyanate (DE-OS 196 28 145), 3,3'-dimethyl-4,4'-biphenylene diisocyanate (TODI, DE-OS 195 09 819), 2,4- and 2,6-tolylene diisocyanate (TDI) and any mixtures of these isomers,

Diphenylmethane-2,4'- and / or -4,4'-diisocyanate (MDI) or naphthylene-1,5-diisocyanate (NDI) are suitable.

Furthermore, according to the invention, for example, triphenylmethane-4,4 ', 4 "-triisocyanate, polyphenyl-polymethylene-polyisocyanates, such as those obtained from

Obtain formaldehyde condensation and subsequent phosgenation and e.g. described in GB-PS 874 430 and GB-PS 848 671, m- and p-isocyanatophenylsulfonyl isocyanates according to US Pat. No. 3,454,606, perchlorinated aryl polyisocyanates as described in US Pat. No. 3,277,138 have carbodiimide groups - Pointing polyisocyanates such as those in US Pat. No. 3,152,162 and in DE-OS 25 04 400, 25

37 685 and 25 52 350 are described, norbornane diisocyanates according to US Pat. No. 3,492,301, polyisocyanates containing allophanate groups, as described in GB Pat. No. 994,890, BE Pat. No. 761,626 and NL-A 7 102 524, isocyanurate groups containing polyisocyanates, as described in US Pat. No. 3,001,973, in German Pat. Nos. 10 22 789, 12 22 067 and 1 027 394 and in DE-OS 1 929 034 and 2 004 048, polyisocyanates containing urethane groups, as described for example in BE-PS 752 261 or described in US Pat. Nos. 3,394,164 and 3,644,457, polyisocyanates containing acylated urea groups according to DE-PS 1,230,778, polyisocyanates containing biuret groups, as described in US Pat. Nos. 3,124,605, 3,201,372 and 3,124,605 and in GB-PS 889 050, polyisocyanates prepared by telomerization reactions as described in US Pat. No. 3,654,106, ester-containing polyisocyanates as described in GB-PS 965,474 and 1,072,956, in US-PSt 3 567 763 and mentioned in DE-PS 12 31 688, reaction products of the above-mentioned isocyanates with acetals according to DE-PS 1 072 385 and polyisocyanates containing polymeric fatty acid esters according to US-PS 3 455 883.

It is also possible to use the distillation residues obtained in industrial isocyanate production and containing isocyanate groups, optionally dissolved in one or more of the aforementioned polyisocyanates. It is also possible to use any mixtures of the aforementioned polyisocyanates.

The technically easily accessible polyisocyanates, e.g. 2,4- and 2,6-tolylene diisocyanate and any mixtures of these isomers ("TDI"), polyphenyl-polymethylene polyisocyanates, such as those produced by aniline-formaldehyde condensation and subsequent phosgenation, are ("crude MDI"), 4 , 4'- and / or 2,4'-diphenylmethane diisocyanate and carbodiimide groups,

Polyisocyanates ("modified polyisocyanates") containing urethane groups, aophanate groups, isocyanurate groups, urea groups or biuret groups, in particular those modified polyisocyanates derived from 2,4- and / or 2,6-tolylene diisocyanate or from 4,4'- and / or 2nd Derive 4'-diphenylmethane diisocyanate. Naphthylene-1,5-diisocyanate and mixtures of the polyisocyanates mentioned are also very suitable.

However, prepolymers containing isocyanate groups are particularly preferably used in the process according to the invention, which are prepared by reacting a partial amount or the total amount of at least one higher molecular weight

Polyhydroxyl compound (b) or a subset or the total amount of Mixture of (b) with at least one low molecular chain extender and / or crosslinking agent (d) with at least one aromatic diisocyanate from the group TDI, MDI, TODI, DIBDI, NDI, DDI, preferably with 4,4'-MDI and / or 2 , 4-TDI and / or 1,5-NDI to a urethane groups, preferably urethane groups and isocyanate groups containing polyaddition product with an NCO content of 0.05 to 8.0 wt .-%, preferably from 1.2 to 7.5 wt .-%.

As already stated, mixtures of (b) and (d) can be used to prepare the prepolymers containing isocyanate groups. According to a preferred embodiment, the prepolymers containing isocyanate groups are prepared by reacting exclusively higher molecular weight polyhydroxyl compounds (b) with the polyisocyanates (a), preferably 4,4'-MDI, 2,4-TDI and / or 1,5- NDI. Difunctional polyhydroxyl compounds with a number average molecular weight of 500 to 6,000, preferably 800 to 3,500 and in particular 1,000 to 3,300, which are selected from the group of polyester polyols, hydroxyl-containing polycarbonates and polyoxyalkylene polyols, are particularly suitable for this purpose.

The prepolymers containing isocyanate groups can be prepared in the presence of catalysts. However, it is also possible to prepare the prepolymers containing isocyanate groups in the absence of catalysts and to incorporate these into the reaction mixture for producing the PUR elastomers.

Suitable higher molecular weight polyhydroxyl compounds b) are those having at least two H atoms reactive toward isocyanate groups; be preferred

Polyester polyols and polyether polyols used. Such polyether polyols can be prepared by known processes, for example by anionic polymerization of alkylene oxides in the presence of alkali metal hydroxides or alkali metal alcoholates as catalysts and with the addition of at least one starter molecule which contains 2 to 3 reactive hydrogen atoms, or by cationic polymerization of alkylene oxides in the presence of Lewis acids such as Antimony pentachloride or boron fluoride etherate. Suitable alkylene oxides contain 2 to 4 carbon atoms in the alkylene radical. Examples are tetrahydrofuran, 1,3-propylene oxide, 1,2- or 2,3-butylene oxide, preferably ethylene oxide and / or 1,2-propylene oxide are used. The alkylene oxides can be used individually, alternately in succession or as mixtures. Come as a starter molecule

Water or dihydric and trihydric alcohols, such as ethylene glycol, propanediol-1,2 and 1,3, diethylene glycol, dipropylene glycol, glycerol, trimethylotpropane etc. The polyether polyols, preferably polyoxypropylene-polyoxyethylene polyols, have a functionality from 2 to 3 and number average molecular weights from 500 to 8,000, preferably 800 to 3,500.

Suitable polyester polyols can be prepared, for example, from organic dicarboxylic acids with 2 to 12 carbon atoms, preferably aliphatic dicarboxylic acids with 4 to 6 carbon atoms and polyhydric alcohols, preferably diols, with 2 to 12 carbon atoms, preferably 2 carbon atoms.

Examples of suitable dicarboxylic acids are: 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 a mixture with one another. Instead of the free dicarboxylic acids, the corresponding dicarboxylic acid derivatives, such as. B. dicarboxylic acid mono and / or diesters of alcohols having 1 to 4 carbon atoms or dicarboxylic acid anhydrides. Dicarboxylic acid mixtures of succinic, glutaric and adipic acid are preferably used in proportions of, for example, 20 to 35/35 to 50/20 to 32 parts by weight, and in particular adipic acid. Examples of two- and multi-valued

Alcohols are ethanediol, diethylene glycol, 1,2- or 1,3-propanediol, dipropylene glycol, methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol 1,6-hexanediol, neopentylglycol, 1.10 -Decanediol, glycerin, trimethylolpropane and pentaerythritol. 1,2-ethanediol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, glycerol, trimethylolpropane or mixtures of at least two of the diols mentioned, in particular mixtures of ethanediol, 1,4-butanediol and 1,6-hexanediol, glycerin and / or trimethylolpropane. Polyester polyols from lactones, for example ε-caprolactone, or hydroxycarboxylic acids, for. B. o-hydroxycaproic acid and hydroxyacetic acid.

The organic, e.g. aromatic and preferably aliphatic polycarboxylic acids and / or derivatives and polyhydric alcohols without catalyst or in the presence of esterification catalysts, advantageously in an atmosphere of insert gases, such as e.g. Nitrogen, carbon monoxide, helium, argon and also in the melt at temperatures from 150 to 300 ° C., preferably 180 to 230 ° C., if appropriate under reduced pressure, up to the desired acid number, which is advantageously less than 10, preferably less than 1 , be polycondensed.

According to a preferred production process, the esterification mixture is polycondensed at the above-mentioned 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 10 to 150 mbar. Examples of suitable esterification catalysts are iron, cadmium, cobalt, lead, zinc, antimony, magnesium, titanium and tin catalysts in the form of metals, metal oxides or metal salts. However, the polycondensation can also be carried out in the liquid phase in the presence of diluents and / or entraining agents, e.g. Benzene, toluene, xylene or chlorobenzene, for azeotropic distillation of the water of condensation.

To prepare the polyester polyols, the organic polycarboxylic acids and / or their derivatives are polycondensed with polyhydric alcohols advantageously in a molar ratio of 1: 1 to 1.8, preferably 1: 1.05 to 1.2. The polyester polyols obtained preferably have a functionality of 2 to 3, in particular 2 to 2.6 and a number average molecular weight of 400 to 6,000, preferably 800 to 3,500. Suitable polyester polyols also include hydroxyl-containing polycarbonates. Suitable polycarbonates containing hydroxyl groups are those of the type known per se which, for example, react with diols, such as 1,2-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, trioxyethylene glycol and / or tetraoxyethylene glycol Diaryl carbonates, for example diphenyl carbonate, or phosgene can be produced.

Silicon dioxide with an average particle diameter of 1 nm to 500 nm, preferably 3 nm to 100 nm, particularly preferably 8-20 nm, is used as the nanoscale filler). The amount of the nanoscale filler is chosen so that the polyurethane elastomer according to the invention contains 0.01 to 20% by weight, preferably 0.2 to 10% by weight, of nanoscale SiO ₂ . The filler is preferably used in the process according to the invention as a dispersion, water or protic or aprotic organic solvents preferably being chosen as the dispersion medium, particularly preferably alcohols, in particular isopropanol. Mixtures of different solvents can of course also be used. The solids content of the dispersions is preferably from 5 to 50% by weight, particularly preferably 15-40% by weight, the solid in the dispersion preferably being completely dispersed and not aggregated. Dispersions which have a pH of 6 to 10, particularly preferably 7 to 9, are preferably used. It has been found that acidic dispersions are more difficult to process than neutral or slightly alkaline dispersions. The stability of the dispersion is ensured by the uniform charging of the surface of the dispersed particles. Such dispersions of nanoparticles can be produced by methods known to those skilled in the art. For example, such

Prepare dispersions by exchanging water for a higher-boiling organic solvent by distillation. Aqueous suspensions of SiO ₂ nanoparticles can be produced, for example, from silica using the sol-gel process. The charge on the surface of the suspended particles can be adjusted by the pH of the solvent, for example anionic surfaces can be adjusted by a sufficiently alkaline medium. Cationic top Areas can be obtained from this, for example, by pH drop, ie the introduction of the suspension in acetic acid, hydrochloric acid, sulfuric acid or the like acidic solutions.

To produce the PUR elastomers according to the invention, in addition to the higher molecular weight polyhydroxyl compounds b) as component d), low molecular weight functional chain extenders and / or low molecular weight, preferably trifunctional or tetrafunctional crosslinking agents or mixtures of chain extenders and crosslinking agents can be used.

Such chain extenders and crosslinking agents d) are used to modify the mechanical properties, in particular the hardness of the PUR elastomers. Suitable chain extenders such as alkane diols, dialkylene glycols and polyalkylene polyols and crosslinking agents, e.g. Trihydric or tetravalent alcohols and oligomeric polyalkylene polyols with a functionality of 3 to 4, usually have molecular weights <800, preferably from 18 to 400 and in particular from 60 to 300. Alkane diols with 2 to 12, preferably, are preferably used as chain extenders 2, 3, 4 or 6 carbon atoms, e.g. 1,2-ethanediol, 1,3-propanediol, 1,5-pentanediol, 1, 6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1, 9-nonanediol, 1,10-decanediol and in particular 1 , 4-butanediol and

Dialkylene glycols with 4 to 8 carbon atoms, e.g. Diethylene glycol and dipropylene glycol as well as polyoxyalkylene glycols. Branched-chain and / or unsaturated alkanediols with usually no more than 12 carbon atoms, such as e.g. 1,2-propanediol, 2-methyl-l, 2-propanediol, 2,2-dimethyl-l, 3-propanediol, 2-butyl-2-ethyl-l, 3-propanediol, 2-butene-l, 4- diol and 2-butyne-1,4-diol,

Diesters of terephthalic acid with glycols having 2 to 4 carbon atoms, such as, for example, terephthalic acid-bis-ethylene glycol or terephthalic acid-bis-1,4-butanediol, hydroxyalkylene ether of hydroquinone or resorcinol, for example 1,4-di- (β-hydroxyethyl) - hydroquinone or 1,3- (β-hydroxyethyl) resorcinol, alkanolamines with 2 to 12 carbon atoms such as ethanolamine, 2-aminopropanol and 3-amino-2,2-dimethylpropanol, N-alkyldialkanolamines, for example N-methyl and N-ethyl-diethanolamine, (cyclo) aliphatic diamines with 2 to 15 carbon atoms, such as 1,2-ethylenediamine, 1,3-propylenediamine, 1, 4-butylenediamine and 1,6-hexamethylenediamine, isophorone-diamine, 1, 4-cyclohexamethylenediamine and 4,4 ' -Diaminodicyclohexylmethane, N- alkyl-, N, N'-dialkyl-substituted and aromatic diamines, which can also be substituted on the aromatic radical by alkyl groups, with 1 to 20, preferably 1 to 4 carbon atoms in the N-alkyl radical, such as N, N'- Diethyl-, N, N'-Di-sec.-pentyl-, N, N'-Di-sec.-hexyl-, N, N'-Di-sec.-decyl- and N, N'-Dicyclo-hexyl -, p- or m-phenylenediamine, N, N'-dimethyl-, N, N'-diethyl-, N, N'-diisopropyl-, N, N'-di-sec-butyl-, N , N'-dicyclohexyl-4,4'-diamino-diphenylmethane, N, N'-di-sec-butylbenzidine, methylene-bis (4-amino-3-benzoic acid methyl ester), 2,4-

Chloro-4,4'-diamino-diphenylmethane, 3,3'-dichloro-4,4'-diaminodiphenylmethane

(MBOCA), 3,5-diamino-4-chlorobenzoic acid ester, diethyltoluenediamine (DETDA), 2,4- and 2,6-toluenediamine.

Also useful as chain extenders and crosslinking agents d) are polyether polyols, preferably those with an average functionality of 2 to 8, a hydroxyl number from 200 to 1 240. These polyether polyols, which have proven themselves as chain extenders and crosslinking agents d), are e.g. Polyoxyethylene polyols started with 1,2-propanediol, water, trimethylolpropane with a hydroxyl number from 630 to 970 and / or with glycerol or trimethylolpropane or one

Glycerol / trimethylolpropane mixture started polyoxypropylene polyols with a hydroxyl number of 210 to 930. Also suitable as polyether polyols are polyoxypropylene polyols with an average functionality of 4 to 8, preferably 4 to 6 and a hydroxyl number of 230 to 500, preferably from 250 to 380, which are obtained under Use of sucrose or sorbitol or mixtures of sucrose and sorbitol as starter molecules, water, propylene glycol, glycerol or mixtures of at least two of the co-starters mentioned additionally being able to be used as co-starters. Also suitable are polyoxypropylene and / or polyoxyethylene polyols with a hydroxyl number of 450 to 750, which can be obtained by reacting pentaerythritol or a mixture of

Pentaerythritol and glycerol and / or trimethylolpropane, advantageously in a molar ratio of pentaerythritol to glycerol and / or trimethylolpropane of 1: 1, with 1,2-propylene oxide or ethylene oxide. Trifunctional and tetrafunctional alcohols, such as glycerol, trimethylolpropane, pentaerythritol and trihydroxycyclohexane and tetrahydroxyalkylenediamines, for example tetra- (2-hydroxyethyl) ethylenediamine or tetra- (2-hydroxypropyl) ethylenediamine, are also very suitable as crosslinking agents.

The compounds of component d) can be used in the form of mixtures or individually. Mixtures of chain extenders and crosslinking agents can also be used.

To adjust the mechanical properties such as The structural components b) and d) can be varied in relatively wide quantitative ratios of the hardness of the PUR elastomers. Depending on the desired properties, the required amounts of the structural components b) and d) can be determined experimentally in a simple manner. 0.5 to are advantageously used

50 parts by weight, preferably 1 to 20 parts by weight of the chain extender and / or crosslinking agent d), based on 100 parts by weight of the higher molecular weight compounds b).

Catalysts familiar to the person skilled in the art can be used as component e), for example tertiary amines such as triethylamine, tributylamine, N-methylmorpholine, N-ethylmorpholine, N, N, N ', N'-tetramethylethylene diamine, pentamethyl-diethylene triamine and higher homologs (DE-OS 26 24 527 and 26 24 528), 1,4-diaza-bicyclo (2,2,2) octane, N-methyl-N'-dimethylaminoethyl-piperazine, bis- (dimethylaminoalkyl) piperazines (DE-OS 26 36 787), N, N-dimethylbenzylamine, N, N-dimethylcyclohexylamine, N, N-diethylbenzylamine, bis- (N, N-diethylaminoethyl) adipate, N, N , N ', N'-tetramethyl-1, 3-butanediamine, N, N-dimethyl-ß-phenyl-ethyl-amine, urea and derivatives of urea - such as N-methyl urea, bis (dimethylamino propyl) urea , N, N'-dimethylurea -, 1,2-dimethylimidazole, 2-methylimidazole, monocyclic and bicyclic amidines (DE-OS 17 20 633), bis (dialkylamino) alkyl ether (US Pat. No. 3,330,782 , DE-AS 10 30 558, DE-OS 18 04 361 and 26 18 280) and amide groups (preferably formamide groups) having tertiary amines according to DE-OS 25 23 633 and 27 32 292). Mannich bases known per se from secondary amines such as dimethylamine and aldehydes, preferably formaldehyde, or ketones such as acetone, methyl ethyl ketone or cyclohexanone and phenols such as phenol or nonylphenol or also come as catalysts

Bisphenol, in question. Tertiary amines which have hydrogen atoms active against isocyanate groups as a catalyst are e.g. Triethanolamine, triisopropanolamine, N-methyl-diethanolamine, N-ethyl-diethanolamine, N, N-dimethylethanolamine, their reaction products with alkylene oxides such as propylene oxide and / or ethylene oxide and secondary tertiary amines according to DE-OS 27 32 292 Silaamines with carbon-silicon bonds, as described in US Pat. No. 3,620,984, can also be used as catalysts, for example 2,2,4-trimethyl-2-silamorpholine and 1,3-diethylaminomethyl-tetramethyl-disiloxane. Furthermore, there are also nitrogen-containing bases such as tetraalkylammonium hydroxides, furthermore alkali hydroxides such as sodium hydroxide, alkali phenolates such as sodium phenolate or alkali alcoholates such as

Sodium methylate into consideration. Hexahydrotriazines can also be used as catalysts (DE-OS 17 69 043). The reaction between NCO groups and Zerewitinoff-active hydrogen atoms is also greatly accelerated by lactams and azalactams, an association being initially formed between the lactam and the compound with acidic hydrogen. Such associates and their catalytic action are described in DE-OS 20 62 286, 20 62 289, 21 17 576, 21 29 198, 23 30 175 and 23 30 211. According to the invention, organic metal compounds, in particular organic tin compounds, can also be used as catalysts. In addition to sulfur-containing compounds such as di-n-octyl-tin mercaptide (US Pat. No. 3,645,927), the organic tin compounds which are preferably tin (II) salts of carboxylic acids such as tin (II) acetate and tin (II) octoate , Tin (II) ethylhexoate and tin (II) laurate and tin (IV) compounds, for example dibutyltin oxide, dibutyltin dichloride, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate or dioctyltin diacetate. Of course, all of the above catalysts can be used as mixtures.

Further representatives of catalysts to be used according to the invention and details of the mode of action of the catalysts can be found in R. Vieweg,

A. Höchtlen (ed.): "Kunststoff-Handbuch", Volume VII, Carl-Hanser-Verlag, Munich 1966, pp. 96-102.

The catalysts or catalyst combinations are generally used in an amount between about 0.001 and 10% by weight, in particular 0.01 to 1% by weight, based on the total amount of compounds having at least two hydrogen atoms which are reactive toward isocyanates.

In the absence of moisture and physically or chemically active blowing agents, compact PUR elastomers, e.g. PUR cast elastomers are manufactured.

For the production of cellular, preferably microcellular PUR elastomers, water is used as blowing agent f), which in situ with the organic polyisocyanates a) or with prepolymers having isocyanate groups to form

Reacts carbon dioxide and amino groups, which in turn react with other isocyanate groups to form urea groups and act as chain extenders.

Since the build-up components b) and d) or the dispersions containing the inorganic nanoscale fillers) may be water-based and / or because of their composition, in some cases it is not necessary to add water separately to the build-up components b), d) or the reaction mixture. However, if water has to be added to the polyurethane formulation in order to set the desired density, this is usually in

Quantities from 0.001 to 3.0 wt .-%, preferably from 0.01 to 2.0 wt .-% and in total in particular from 0.2 to 1.2% by weight, based on the weight of the structural components a), b) and, if appropriate, d), are used.

Instead of water or preferably in combination with water, gases or readily volatile inorganic or organic can also be used as blowing agents f)

Substances which evaporate under the influence of the exothermic polyaddition reaction and which advantageously have a boiling point under normal pressure in the range from -40 to 120 ° C., preferably from 10 to 90 ° C., are used as physical blowing agents. As organic blowing agents come e.g. Acetone, ethyl acetate, halogen-substituted alkanes such as methylene chloride, chloroform, ethylidene chloride,

Vinylidene chloride, monofluorotrichloromethane, chlorodifluoromethane, dichlorodifluoromethane, furthermore butane, hexane, heptane or diethyl ether, as inorganic blowing agents, for example air, CO or N ₂ O, in question. A blowing effect can also be achieved by adding compounds which are released at temperatures above room temperature with the elimination of gases, for example nitrogen and / or

Carbon dioxide, decompose like azo compounds e.g. Azodicarbonamide or azoisobutyronitrile, or salts such as ammonium bicarbonate, ammonium carbamate or ammonium salts of organic carboxylic acids, e.g. the monoammonium salts of malonic acid, boric acid, formic acid or acetic acid. Further examples of blowing agents as well as details on the use of blowing agents can be found in R. Vieweg,

A. Höchtlen (ed.): "Kunststoff-Handbuch", Volume VII, Carl-Hanser-Verlag, Munich 1966, pp. 108f, 453ff and 507-510.

The appropriate amount of solid blowing agents, low-boiling liquids or gases to be used, each individually or in the form of mixtures, e.g. as

Liquid or gas mixtures or as gas-liquid mixtures can depend on the density that you want to achieve and the amount of water used. The required amounts can easily be determined experimentally. Satisfactory results usually provide amounts of solids of 0.5 to 35 parts by weight, preferably 2 to 15 parts by weight, liquid amounts of

1 to 30 parts by weight, preferably 3 to 18 parts by weight and / or gas amounts from 0.01 to 80 parts by weight, preferably from 10 to 35 parts by weight, based in each case on the weight of the structural components a), b) and, if appropriate, d). The gas loading with, for example, air, carbon dioxide, nitrogen and / or helium can be carried out both via the higher molecular weight polyhydroxyl compound b), via the low molecular chain extender and / or crosslinking agent d) and also via the polyisocyanates a) or via a) and b) and if necessary, d).

Additives g) can optionally be incorporated into the reaction mixture for producing the compact and / or cellular PUR elastomers. Examples include surface-active additives such as emulsifiers, foam stabilizers, cell regulators, flame retardants, nucleating agents, oxidation retarders, stabilizers, lubricants and mold release agents, dyes, dispersants and pigments. The emulsifiers are e.g. the sodium salts of castor oil sulfonates or salts of fatty acids with amines such as oleic acid diethylamine or stearic acid diethanolamine in question. Also alkali or ammonium salts of

Sulphonic acids such as dodecylbenzenesulphonic acid or dinaphthylmethane disulphonic acid or fatty acids such as ricinoleic acid or polymeric fatty acids can also be used as surface-active additives. Foam stabilizers in particular are polyether siloxanes, especially water-soluble representatives. These compounds are generally constructed in such a way that a copolymer of ethylene oxide and propylene oxide is linked to a polydimethylsiloxane radical. Such foam stabilizers are e.g. in U.S. Patents 2,834,748, 2,917,480 and 3,629,308. Of particular interest are polysiloxane-polyoxyalkylene copolymers branched via AUophanate groups in accordance with DE-OS 25 58 523. Other organospolysiloxanes, oxyethylated alkylphenols, oxyethylated fatty alcohols, paraffin oils, castor oil or ricinoleic acid esters, turkish red oil and peanut oil and cell regulators such as paraffin oil are also suitable , Fatty alcohols and dimethylpolysiloxanes. Oligomeric polyacrylates with polyoxyalkylene and fluoroalkane radicals are also suitable as side groups for improving the emulsifying effect, the dispersion of the filler, the cell structure and / or for stabilizing them.

The surface-active substances are usually used in amounts of 0.01 to 5 Parts by weight, based on 100 parts by weight of the higher molecular weight polyhydroxyl compounds b) applied. Reaction retarders, for example acidic substances such as hydrochloric acid, or organic acids and acid halides, cell regulators known per se such as paraffins or fatty alcohols or dimethylpolysiloxanes as well as pigments or dyes and flame retardants known per se, for example tris-chloroethyl phosphate, tricresyl phosphate or ammonium phosphate and -polyphosphate, also stabilizers against aging and weather influences, plasticizers and fungistatic and bacteriostatic substances.

Further examples of surface-active additives and foam stabilizers to be used according to the invention, as well as cell regulators, reaction retarders, stabilizers, flame-retardant substances, plasticizers, dyes and fillers, as well as fungistatic and bacteriostatic substances, and details on the use and action of these additives are given in R. Vieweg, A. Höchtlen (ed.): "Kunststoff-Handbuch", Volume VII,

Carl-Hanser-Verlag, Munich 1966, p.103-113.

The PUR elastomers according to the invention can be produced in several variants. For example, mixtures of higher molecular weight polyhydroxyl compound b), optionally low molecular weight chain extender and / or crosslinking agent d) and optionally chemical blowing agents, preferably water, can be reacted with organic polyisocyanates a). In a preferred embodiment of the process, prepolymers containing isocyanate groups from a), b) and c) are reacted with chain extenders and or crosslinking agents d), or with mixtures of subsets of b) and d), or mixtures of d) and Water, or preferably with mixtures of subsets of b), d) and water.

The components are reacted in amounts such that the equivalence ratio of the NCO groups of the polyisocyanates a) to the sum of the isocyanate group-reactive hydrogens of components b), c), d) and such as any chemical blowing agent used is 0.8: 1 to 1.2: 1, preferably 0.95: 1 to 1.15: 1 and in particular 1.00: 1 to 1.10: 1.

In a preferred variant of the method according to the invention, a dispersion of the nanoscale filler c) in a protic or aprotic

Solvent or in a mixture of protic and or aprotic solvents of the higher molecular weight polyhydroxyl compound b) and / or optionally the low molecular weight chain extender and / or crosslinking agent d) is added and the solvent of component c) is optionally distilled off. Suitable solvents are e.g. Water, methanol, ethanol, isopropanol, 1,2-ethanediol, 1, 4-butanediol, 1, 6-hexanediol, THF, diethyl ether, pentane, cyclopentane, hexane, heptane, toluene, acetone, 2-butanone or dilute acids such as hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid and mixtures of the solvents mentioned.

In a further variant of the process according to the invention, dispersions of nanoscale filler c) in solvents which are inert to NCO groups, such as acetone, tetrahydrofuran or hydrocarbons, e.g. Pentane, hexane, heptane, cyclohexane, toluene, the polyisocyanate a) or an isocyanate group-containing prepolymer.

However, the filler can also be in the form of a powder, in which the primary particles of the filler can also be agglomerated, in the di- and / or polyisocyanate a) and / or in the higher molecular weight polyhydroxyl compound b) and / or optionally in the low molecular chain extender and / or Crosslinking agents d) are introduced. The shear forces that occur when the powder is incorporated release from the in

Powder in agglomerated form the nanoparticles present the primary particles so that they are dispersed in the system component. When using dispersion technology, care must be taken that fillers in which there are strong interactions between the primary particles are redispersed at high shear rates; apparatus suitable for this are known to the person skilled in the art (G.W. Becker,

D. Braun (ed.): "Kunststoff-Handbuch", Volume 7, 3rd edition, Carl-Hanser-Verlag, Munich, Vienna 1993, pp. 139 ff. And the article by P. Walstra: "Formation of Emulsions" in "Encyclopedia of Emulsions Technology", Vol. 1, Decker-Verlag, New York, Basel, 1983. The filler content of the invention PUR elastomers is generally 0.1 to 20% by weight, preferably 0.2 to 10% by weight, particularly preferably 0.3-10% by weight.

The PUR elastomers according to the invention can be prepared by the processes described in the literature, e.g. the one-shot or the prepolymer process, with the aid of mixing devices known in principle to the person skilled in the art. They are preferably produced by the prepolymer process.

In one embodiment of the production of the PUR elastomers according to the invention, the starting components are mixed homogeneously in the absence of blowing agents f), usually at a temperature of 80 to 160 ° C., preferably 110 to 150 ° C., and the reaction mixture is introduced into an open, optionally tempered mold and allowed to harden. In a further variant of the production of the PUR elastomers according to the invention, the structural components are mixed in the same way in the presence of blowing agents f), preferably water, and poured into the mold, which may be tempered. After filling, the mold is closed and the reaction mixture is left under compression, e.g. Foam with a degree of compaction from 1.1 to 8, preferably from 1.2 to 6 and in particular 2 to 4 to form shaped articles. As soon as the moldings have sufficient strength, they are removed from the mold. The demolding times include depending on the temperature and geometry of the mold and the reactivity of the reaction mixture and are usually

10 to 60 minutes.

Depending on the filler content and type, compact PUR elastomers according to the invention have a density of 1.1 to 1.8 g / cm ³ (for comparison: corresponding filler-free products have a density of 1.0 to 1.4 g / cm ³ , preferably 1.1 up to 1.25 g / cm). Cellular PUR elastomers according to the invention have densities of 0.2 to 1.8 g / cm, preferably 0.35 to 1 g / cm.

The PUR elastomers according to the invention show increased heat resistance under dynamic stress and can therefore be used up to a higher temperature range. At higher temperatures (> 80 ° C) they show a lower loss factor (tan θ) compared to the elastomer not filled with nanoscale fillers. The crystallization in the soft segment and in the hard segment of the elastomers according to the invention is increased by the nanoscale filler.

The PUR elastomers according to the invention are used for the production of moldings, preferably for mechanical engineering and the transport sector. The cellular PUR elastomers are particularly suitable for the manufacture of damping and spring elements, for example for means of transport, preferably motor vehicles, buffers and cover layers. The compact PUR elastomers are suitable, for example, for use in tires, rolls and rollers, as roller coatings or for the production of belts.

Examples

In the examples, the nanoscale filler was in the form of a 30.2% by weight SiO ₂ with an average particle size of approx. 9 nm and a specific surface area of 300 m ² / g in dispersion containing isopropanol with a pH of 8- 9 used (Organosol ^® 300, Bayer AG).

Comparative Example I a) Preparation of a prepolymer having isocyanate groups based on 1,5-NDI

1,000 parts by weight (0.5 mol) of a poly (ethanediol-1,4-butanediol adipate) (molar ratio of ethanediol: 1,4-butanediol: adipic acid 1: 1: 2) with a number average molecular weight of 2,000 ( calculated from the experimentally determined hydroxyl number), 11.05 parts by weight of castor oil (manufacturer: Alberdingk Boley GmbH) and 16.68 parts by weight

Parts of 2,2 ', 6,6'-tetraisopropyldiphenylcarbodiimide were heated to 125 ° C. and 272 parts by weight (1.30 mol) of solid 1,5-NDI were added at this temperature with vigorous stirring and brought to reaction. A prepolymer with an NCO content of 5.15% by weight was obtained.

b) Production of cellular molded parts

The crosslinker component consisted of 80.74% by weight of a poly (ethanediol-1,4-butanediol adipate) (molar ratio of ethanediol: 1,4-butanediol: adipic acid 1: 1: 2), 8.68% by weight of water , 8.68% by weight sodium salt of sulfated castor oil

(Manufacturer: Rheinchemie), 1.74% by weight of a mixture of ethoxylated oleic and ricinoleic acid with an average of 9 oxyethyl units and the monoethanolamine salt of n-alkylbenzenesulfonic acid with C ₉ to C ₅ alkyl residues (manufacturer: Rheinchemie) and 1 , 27% by weight of dimethylcyclohexylamine. 100 parts by weight of the isocyanate prepolymer prepared according to a) and heated to 90 ° C. were vigorously stirred with 10.62 parts by weight of the crosslinking component for about 20 seconds. The reaction mixture was then poured into a closable, metallic molding tool heated to 90 ° C., the molding tool was sealed and the reaction mixture was allowed to harden. After 25 minutes, the microcellular molded body was removed from the mold and heat-treated at 110 ° C. for 16 hours for thermal post-curing.

Comparative Example II a) Preparation of a prepolymer containing isocyanate groups on 4,4'-

MDI-based

1,000 parts by weight (0.5 mol) of a poly (ethanediol adipate) with a number average molecular weight of 2000 (calculated from the experimentally determined hydroxyl number) was heated to 80 ° C and at this temperature with 215 parts by weight (0, 86 mol) of 4,4'-MDI were added with vigorous stirring and brought to reaction. A prepolymer with an NCO content of 2.50% by weight was obtained.

b) Production of massive molded parts

The crosslinker component consisted of 84.74% by weight of a poly (ethanediol adipate), 15.26% by weight of 1,4-butanediol and 100 ppm of dibutyltin dilaurate.

100 parts by weight of the isocyanate prepolymer prepared according to a) and heated to 80 ° C. were vigorously stirred with 13.0 parts by weight of the crosslinking component for about 3 minutes. The reaction mixture was then poured into a closable, metallic mold which was heated to 110 ° C., the mold was sealed and the reaction mixture was allowed to harden. After 16 hours, the massive molded body was removed from the mold. Comparative Example III a) Preparation of a prepolymer having isocyanate groups based on 1,5-NDI

1,000 parts by weight (0.5 mol) of a poly (ethanediol adipate) with a number average molecular weight of 2,000 (calculated from the experimentally determined hydroxyl number) were heated to 125 ° C and at this temperature with 180 parts by weight (0 , 86 mol) of solid 1,5-NDI are added with vigorous stirring and brought to reaction. A prepolymer with an NCO content of 2.54% by weight was obtained.

b) Production of massive molded parts

The crosslinker component consisted of 1,4-butanediol.

100 parts by weight of the isocyanate prepolymer prepared according to a) and heated to 125 ° C. were stirred vigorously with 1.69 parts by weight of the crosslinking component for about 2 minutes. The reaction mixture was then poured into a closable, metal mold that was heated to 110 ° C., the mold was closed and the reaction mixture was allowed to harden. After 25

The solid molded body was demolded for minutes and annealed at 110 ° C for 16 hours for thermal post-curing.

Comparative Example IV a) Preparation of a SiO-containing, N-based prepolymer containing isocyanate groups

1,000 parts by weight (0.5 mol) of a poly (ethanediol-1,4-butanediol adipate) (molar ratio of ethanediol: 1,4-butanediol: adipic acid 1: 1: 2) with a number average molecular weight of 2,000 ( calculated from the experimentally determined hydroxyl number), in which 71 parts by weight of SiO ₂ (Aldrich No. 342890, -325 mesh) had been dispersed, 11.05 parts by weight of castor oil (manufacturer: Alberdingk Boley GmbH) and 16.68 parts by weight of 2, 2 ', 6,6'-tetraisopropyldiphenylcarbodiimide are mixed, the mixture is then heated to 125 ° C. and 272 parts by weight (1.30 mol) of solid 1,5-NDI are added at this temperature with vigorous stirring and brought to reaction. A prepolymer with an NCO content of 5.12% by weight was obtained.

b) Production of cellular molded parts

The crosslinker component consisted of 80.74% by weight of a poly (ethanediol-1,4-butanediol adipate) (molar ratio of ethanediol: 1,4-butanediol: adipic acid 1: 1: 2), 8.68% by weight of water, 8 , 68% by weight sodium salt of sulfated castor oil (manufacturer: Rheinchemie), 1.74% by weight of a mixture of ethoxylated oleic and ricinoleic acid with an average of 9 oxyethyl units and the monoethanolamine salt of n-alkylbenzenesulfonic acid with C ₉ to cis Alkyl residues (manufacturer: Rheinchemie) and 1.27% by weight dimethylcyclohexylamine.

100 parts by weight of the isocyanate prepolymer prepared according to a) and heated to 90 ° C. were mixed with 10.62 parts by weight of the crosslinking component

Vigorously stirred for seconds. The reaction mixture was then poured into a closable, metallic molding tool heated to 90 ° C., the molding tool was sealed and the reaction mixture was allowed to harden. After 25 minutes, the microcellular molded article was removed from the mold and annealed at 110 ° C. for 16 hours for thermal post-curing. Example 1 a) Preparation of a prepolymer containing isocyanate groups and containing SiO ₂ nanoparticles and based on 1,5-NDI

1,000 parts by weight (0.5 mol) of a poly (ethanediol-1,4-butanediol adipate) (molar ratio of ethanediol: 1,4-butanediol: adipic acid 1: 1: 2) with a number average molecular weight of 2,000 ( calculated from the experimentally determined hydroxyl number) are mixed with 238 parts by weight of a 30.2% by weight dispersion of SiO ₂ (average particle diameter approx. 9 nm) in isopropanol with vigorous stirring and the isopropanol in vacuo distilled off at 110 ° C. Be in this mixture

11.05 parts by weight of castor oil (manufacturer: Alberdingk Boley GmbH) and 16.68 parts by weight of 2,2 ', 6,6'-tetraisopropyldiphenyl-carbodiimide, the mixture was then heated to 125 ° C. and at this temperature mixed with 272 parts by weight (1.30 mol) of solid 1,5-NDI with vigorous stirring and brought to reaction. A prepolymer with an NCO content of 5.12% by weight was obtained.

b) Production of cellular molded parts

The crosslinker component consisted of 80.74% by weight of a poly (ethanediol-1,4-butanediol adipate) (molar ratio of ethanediol: 1,4-butanediol: adipic acid 1: 1: 2), 8.68

% By weight of water, 8.68% by weight of sodium salt of sulfated castor oil (manufacturer: Rheinchemie), 1.74% by weight of a mixture of ethoxylated oleic and ricinoleic acids with an average of 9 oxyethyl units and the monoethanolamine salt of n-alkylbenzenesulfonic acid _Cς> - Cι to ₅ alkyl groups (manufactured by Rhein Chemie) and 1.27 wt .-% of dimethylcyclohexylamine.

100 parts by weight of the isocyanate prepolymer prepared according to a) and heated to 90 ° C. were vigorously stirred with 10.62 parts by weight of the crosslinking component for about 20 seconds. The reaction mixture was then poured into a closable, metallic mold which was heated to 90 ° C. and which

The mold was closed and the reaction mixture was allowed to harden. After 25 minutes, the microcellular molded body was removed from the mold and annealed at 110 ° C. for 16 hours for thermal post-curing.

Example 2 a) Preparation of a prepolymer containing 4,4'-MDI and containing isocyanate groups and containing SiO ₂ nanoparticles

1,000 parts by weight (0.5 mol) of a poly (ethanediol adipate) with a number average molecular weight of 2,000 (calculated from the experimentally determined hydroxyl number) were 30.2% by weight with 195.1 parts by weight Dispersion of SiO ₂ (average particle diameter approx. 9 nm) in iso-propanol is added with vigorous stirring and the iso-propanol is distilled off in vacuo at 80 ° C. The mixture was then heated to 50 ° C. and 149.9 parts by weight (0.86 mol) of 4,4′-MDI were added at this temperature, with vigorous stirring, and the mixture was reacted.

A prepolymer with an NCO content of 2.48% by weight was obtained.

b) Production of massive molded parts containing SiO ₂ nanoparticles. The crosslinker component consisted of 1,4-butanediol.

100 parts by weight of the isocyanate prepolymer prepared according to a) and heated to 90 ° C. were stirred vigorously with 2.48 parts by weight of the crosslinking component for about 20 seconds. The reaction mixture was then poured into a closable, metallic mold that was heated to 120 ° C., the mold was closed and the solid mold body was used for thermal purposes

Post-curing annealed at 120 ° C for 16 hours and then demolded. Example 3 a) Preparation of a prepolymer containing isocyanate groups and containing SiO ₂ nanoparticles and based on 1,5-NDI

1,000 parts by weight (0.5 mol) of a poly (ethanediol adipate) with a number average

Molecular weight of 2000 (calculated from the experimentally determined hydroxyl number) were mixed with 209.1 parts by weight of a 30.2% by weight dispersion of SiO ₂ (average particle diameter approx. 9 nm) in isopropanol with vigorous stirring and the isopropanol is distilled off in vacuo at 80.degree. The mixture was then heated to 125 ° C and at this temperature with 180 parts by weight

(0.86 mol) of solid 1,5-NDI was added with vigorous stirring and brought to reaction. A prepolymer with an NCO content of 2.52% by weight was obtained.

b) Production of Solid Moldings Containing SiO ₂ Nanoparticles The crosslinking component consisted of 1,4-butanediol.

100 parts by weight of the isocyanate prepolymer prepared according to a) and heated to 90 ° C. were vigorously stirred with 1.69 parts by weight of the crosslinking component for about 20 seconds. The reaction mixture was then poured into a closable, metal mold which was heated to 120 ° C. and which

The mold was closed and the reaction mixture was allowed to harden. After 25 minutes, the massive molded body was removed from the mold and annealed at 120 ° C. for 16 hours for thermal post-curing.

Example 4 a) Preparation of a prepolymer containing isocyanate groups and containing SiO ₂ nanoparticles and based on 1,5-NDI

1,000 parts by weight (0.5 mol) of a poly (ethanediol adipate) with a number average

Molecular weight of 2,000 (calculated from the experimentally determined hydroxyl number) were mixed with 20.9 parts by weight of a 30.2% by weight dispersion of SiO ₂ (average particle diameter approx. 9 nm) in isopropanol with vigorous stirring and distilled off the iso-propanol in vacuo at 80 ° C. The mixture was then heated to 125 ° C and at this temperature with 180 parts by weight

(0.86 mol) of solid 1,5-NDI was added with vigorous stirring and brought to reaction. A prepolymer with an NCO content of 2.52% by weight was obtained.

b) Production of Solid Moldings Containing SiO ₂ Nanoparticles The crosslinker component consisted of 1,4-butanediol.

100 parts by weight of the isocyanate prepolymer prepared according to a) and heated to 90 ° C. were vigorously stirred with 1.69 parts by weight of the crosslinking component for about 20 seconds. The reaction mixture was then poured into a closable, metallic mold that was heated to 120 ° C., the mold was sealed and the reaction mixture was allowed to harden. After 25 minutes, the massive molded body was removed from the mold and annealed at 120 ° C. for 16 hours for thermal post-curing.

Example 5 a) Preparation of a prepolymer containing isocyanate groups and containing SiO ₂ nanoparticles and based on 1,5-NDI

1,000 parts by weight (0.5 mol) of a poly (ethanediol adipate) with a number average

Molecular weight of 2,000 (calculated from the experimentally determined hydroxyl number) were mixed with 83.6 parts by weight of a 30.2% by weight dispersion of SiO ₂ (average particle diameter approx. 9 nm) in isopropanol with vigorous stirring and the isopropanol in vacuo at 80 ° C distilled off. The mixture was then heated to 125 ° C. and, at this temperature, 180 parts by weight (0.86 mol) of solid 1,5-NDI were added with vigorous stirring and brought to reaction. A prepolymer with an NCO content of 2.52% by weight was obtained.

b) Production of Solid Moldings Containing SiO ₂ Nanoparticles The crosslinker component consisted of 1,4-butanediol

100 parts by weight of the isocyanate prepolymer prepared according to a) and heated to 90 ° C. were vigorously stirred with 1.69 parts by weight of the crosslinking component for about 20 seconds. The reaction mixture was then poured into a closable, metallic molding tool tempered at 120 ° C., the molding tool was sealed and the reaction mixture was allowed to harden. After 25

The massive molded body was demolded for minutes and annealed at 120 ° C for 16 hours for thermal post-curing.

Example 6 a) Preparation of a prepolymer containing isocyanate groups and containing SiO ₂ nanoparticles and based on 1,5-NDI

1,000 parts by weight (0.5 mol) of a poly (ethanediol-1,4-butanediol adipate) (molar ratio of ethanediol: 1,4-butanediol: adipic acid 1: 1: 2) with a number average molecular weight of 2,000 ( calculated from the experimentally determined hydroxyl number) are mixed with 95 parts by weight of a 30.2% by weight dispersion of SiO ₂ (average particle diameter approx. 9 nm) in isopropanol with vigorous stirring and the isopropanol in vacuo distilled off at 110 ° C. 11.05 parts by weight of castor oil (manufacturer: Alberdingk Boley GmbH) and 16.68 parts by weight of

Parts 2,2 ', 6,6'-tetraisopropyldiphenyl-carbodiimide stirred in, the mixture then warmed to 125 ° C. and mixed with 272 parts by weight (1.30 mol) of solid 1,5-NDI at this temperature with vigorous stirring and brought to reaction. A prepolymer with an NCO content of 5.12% by weight was obtained.

b) Production of cellular molded parts

The crosslinker component consisted of 80.74% by weight of a poly (ethanediol-1,4-butanediol adipate) (molar ratio of ethanediol: 1,4-butanediol: adipic acid 1: 1: 2), 8.68% by weight of water, 8 , 68% by weight sodium salt of sulfated castor oil (manufacturer: Rheinchemie), 1.74% by weight of a mixture of ethoxylated oleic and ricinoleic acid with an average of 9 oxyethyl units and the monoethanolamine salt of n-alkylbenzenesulfonic acid with C ₉ - to C, ₅ Alkyl residues (manufacturer: Rheinchemie) and 1.27% by weight dimethylcyclohexylamine.

100 parts by weight of the isocyanate prepolymer prepared according to a) and heated to 90 ° C. were vigorously stirred with 10.62 parts by weight of the crosslinking component for about 20 seconds. The reaction mixture was then poured into a closable, metallic molding tool heated to 90 ° C., the molding tool was sealed and the reaction mixture was allowed to harden. After 25 minutes, the microcellular molded body was removed from the mold and annealed at 110 ° C. for 16 hours for thermal post-curing.

Example 7

a) Preparation of a prepolymer containing isocyanate groups and containing SiO ₂ nanoparticles on a 1,5-NDI basis

1,000 parts by weight (0.5 mol) of a poly (ethanediol-1,4-butanediol adipate) (molar ratio of ethanediol: 1,4-butanediol: adipic acid 1: 1: 2) with a number-average

Molecular weight of 2,000 (calculated from the experimentally determined hydroxyl number) are mixed with 24 parts by weight of a 30.2% by weight dispersion of SiO ₂ (average particle diameter approx. 9 nm) in isopropanol with vigorous stirring and the isopropanol is distilled off in vacuo at 110.degree , 11.05 parts by weight of castor oil (manufacturer: Alberdingk Boley GmbH) and 16.68 parts by weight of 2,2 ', 6,6'-tetraisopropyldiphenylcarbodiimide are stirred into this mixture, and the mixture is then heated to 125.degree and at this temperature 272 parts by weight (1.30 mol) of solid 1,5-NDI were added with vigorous stirring and brought to reaction. A prepolymer with an NCO content of 5.12% by weight was obtained.

b) Production of cellular molded parts

The crosslinker component consisted of 80.74% by weight of a poly (ethanediol-1,4-butanediol adipate) (molar ratio of ethanediol: 1,4-butanediol: adipic acid 1: 1: 2), 8.68% by weight of water, 8 , 68% by weight sodium salt of sulfated castor oil (manufacturer: Rheinchemie), 1.74% by weight of a mixture of ethoxylated oleic and ricinoleic acid with an average of 9 oxyethyl units and the monoethanolamine salt of n-alkylbenzenesulfonic acid with Cg to cis alkyl residues ( Manufacturer: Rheinchemie) and 1.27% by weight dimethylcyclohexylamine.

100 parts by weight of the isocyanate prepolymer prepared according to a) and heated to 90 ° C. were vigorously stirred with 10.62 parts by weight of the crosslinking component for about 20 seconds. The reaction mixture was then poured into a closable, metallic molding tool heated to 90 ° C., the molding tool was sealed and the reaction mixture was allowed to harden. After 25 minutes, the microcellular molded body was removed from the mold and annealed at 110 ° C. for 16 hours for thermal post-curing.

The mechanical properties of the elastomers produced in the examples are summarized in the table below. The compression set was measured based on DIN 53 572; Tensile strength and elongation at break were in

Tensile test according to DIN 53 455 and tear strength in the tensile test according to DIN 53 515 determined; Module values or the associated values for tan δ and the heat level as temperature for the module value at 1 MPa were taken from the measurement curves of a dynamic mechanical analysis according to DIN 53 445.

Tab. 1: Static and dynamic properties of the solid and cellular PUR elastomers according to comparative examples u

Examples

⁾Ermittelt aus TEM-Aufhahmen der entsprechenden Proben nach der Methode der Bestimmung des Durchmessers flächengleic

⁾ Determined from TEM recordings of the corresponding samples according to the method of determining the diameter flat

Circles. *) According to the evaluation of the TEM images, the nanoscale filler is not aggregated and completely dispersed in the polymer material.

Claims

claims 1. Compact and / or cellular polyurethane elastomers containing 0.01 to 20% by weight of nanoscale SiO ₂ with an average particle diameter of 1 to 500 nm, the particles not being aggregated. 2. A process for the preparation of the elastomers according to claim 1 by reacting a) di- and / or polyisocyanates with b) higher molecular weight polyhydroxyl compounds, c) a nanoscale filler, and if necessary d) low molecular weight chain extenders and / or crosslinking agents, e) catalysts, f) blowing agents and g) additives, which is characterized in that the nanoscale filler used is nanoscale SiO ₂ or a filler which is present as nanoscale SiO ₂ in the resulting PUR elastomer by using a suitable process. A method according to claim 2, in which the nanoscale filler c) is added to the higher molecular weight polyhydroxyl compounds b) or to the low molecular weight chain extenders and / or crosslinking agents d). 4. The method according to claim 3, wherein the nanoscale filler c) the higher molecular weight polyhydroxyl compounds b) or the lower molecular weight Chain extenders and / or crosslinking agents d) are added in the form of a dispersion in a solvent and the solvent is then distilled off. 5. The method according to claim 2, wherein the nanoscale filler c) as Dispersion in a solvent which is inert to isocyanate groups is added to the di- or polyisocyanates a) or to a prepolymer which has been prepared using at least some of the di- or polyisocyanates a) and at least some of the higher molecular weight polyhydroxyl compounds b). 6. molded article containing polyurethane lastomers according to claim 1. 7. damping and spring elements containing polyurethane elastomers according to claim 1.