WO2012098145A1

WO2012098145A1 - Microcellular foams with improved mechanical properties

Info

Publication number: WO2012098145A1
Application number: PCT/EP2012/050686
Authority: WO
Inventors: Andreas Eipper; Andreas Kunst; Nils Mohmeyer; Frank Prissok; Ulrich Holwitt; Heinrich Bollmann; Daniel Freidank; Henning WETTACH
Original assignee: Basf Se
Priority date: 2011-01-21
Filing date: 2012-01-18
Publication date: 2012-07-26

Abstract

The invention relates to a cellular polyisocyanate polyaddition product that can be obtained by mixing a) polyisocyanates including at least one polyisocyanate selected from the group consisting of 1,5-naphthylene diisocyanate (NDI), ditolyl diisocyanate (TODI), and diphenylethane diisocyanate (EDI), b) high-molecular-weight compounds with groups that are reactive towards isocyanate groups, c) optionally crosslinking agents, d) solid particles, e) water, f) optionally catalysts, g) optionally foaming agents, and h) optionally other additives into a reaction mixture, and allowing the reaction mixture to fully cure.

Description

The invention relates to cellular polyisocyanate polyaddition products, preferably cellular polyurethane elastomers, more preferably those having a density according to DIN 53420 of 200 to 1 100, preferably 300 to 800 kg / m ³ , and their use.

Furthermore, the invention relates to cellular polyisocyanate polyaddition products obtainable in this way and their use. The patent application makes reference to the priority documents EP 1 1 151667.0 and US 61/434 860, which are part of this application.

Cellular, for example, microcellular polyisocyanate polyaddition products, usually polyurethanes and / or polyisocyanurates, obtainable by reacting isocyanates with isocyanate-reactive compounds and processes for their preparation are well known. A particular embodiment of these products are cellular, in particular microcellular polyurethane elastomers, which differ from conventional polyurethane foams by their significantly higher density of 300 to 600 kg / m ³ , their particular physical properties and the possible applications thereof. Such polyurethane elastomers are used, for example, as vibration and shock-absorbing elements, in particular in the automotive industry. The suspension elements made of polyurethane elastomers are pushed in automobiles, for example, within the Gesamtfederbeinkonstruktion consisting of shock absorber, coil spring and the elastomeric spring on the piston rod of the shock absorber.

Other requirements of the cellular polyisocyanate polyaddition products are good dynamic mechanical and static mechanical properties, such as excellent tensile strength, elongation, tear propagation resistance and compression set behavior, so that the polyurethane elastomers meet the high mechanical requirements that are placed on the damping elements over the longest possible period can.

According to EP-A 62 835 closed-cell polyurethane moldings are described with a compacted edge zone, which are obtainable by reacting an isocyanate-terminated prepolymer with water in a mold with a surface temperature of the mold inner wall of 50 to 70 ° C. The molded parts can be used for example as damping elements in the automotive industry. The low water absorption described for these moldings results primarily from the compacted edge zone. A subsequent mechanical processing of the parts, for example by cutting or twisting can damage or destroy this edge zone and allow water absorption. In addition, a shorter demolding time is desirable.

WO 2009/063004 discloses a foamed polyurethane which is obtainable by mixing a) polyisocyanates, b) relatively high molecular weight compounds with respect to isocyanate n) reactive groups, c) solid particles, d) blowing agents, e) optionally chain extenders, crosslinking agents or mixtures thereof, f) optionally catalyst and g) optionally other additives, to a reaction mixture and reacting the reaction mixture. The foamed polyurethanes are used as polyurethane integral foams for the production of shoe soles or automotive interior parts, such as steering wheels, headrests, car door side panels, car instrument panels, car center consoles or control buttons.

The polyisocyanates (a) are ^{4,4-diphenylmethane} diisocyanate, 2,4 ^{'-Diphenylmethandiiso-} diisocyanate, the mixtures of monomeric diphenylmethane diisocyanates and higher nuclear

Homologs of diphenylmethane diisocyanate (polymer-MDI), tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 2,4- and 2,6-tolylene diisocyanate (TDI) mentioned as preferred 4,4'-MDI is called. WO 00/63279 discloses microcellular polyurethane elastomers with reduced water absorption for the production of damping elements for motor vehicles, wherein the microcellular polyurethane elastomers are obtainable from a) isocyanates,

b) compounds reactive toward isocyanates,

c) polysiloxanes,

d) 0 to 1% by weight of fatty acid sulfonates, based on the weight of the cellular polyisocyanate polyaddition products,

e) water and optionally

f) catalysts,

g) propellant and / or

h) auxiliaries or additives.

As preferred isocyanates a) are optionally modified 2,2-, 2,4- and 4,4-diphenyl methane diisocyanate (MDI), 1, 5-naphthylene diisocyanate (NDI), 2,4- and 2,6-toluene diisocyanate (TDI ) and their mixtures. The concomitant use of fillers or solid particles is not mentioned.

The object of the invention is to develop cellular, preferably closed-cell polyisocyanate polyaddition products, preferably cellular polyurethane elastomers having a density of from 200 to 1100, preferably from 300 to 800, kg / m ³ with improved properties. In particular, the tensile strength according to DIN 53571, the elongation according to DIN 53571, the tear strength according to DIN 53515 and the dynamic stability should be improved.

The object according to the invention is achieved by a cellular polyisocyanate polyaddition product obtainable by mixing a) polyisocyanates containing at least one polyisocyanate selected from the group consisting of 1, 5-naphthylene diisocyanate, ditolyl diisocyanate and diphenylethane diisocyanate,

b) relatively high molecular weight compounds having isocyanate-reactive groups, c) optionally crosslinking agents,

d) solid particles,

e) water,

f) optional catalysts,

g) optional blowing agents,

h) optionally other additives, to a reaction mixture and reacting the reaction mixture. The constituents a) to h) are also addressed as components a) to h). According to the invention, the polyisocyanate component a) comprises a polyisocyanate or a mixture of two or three of the polyisocyanates selected from the group consisting of 1,5-naphthylene diisocyanate (NDI), ditolyl diisocyanate (TODI) and diphenylethane diisocyanate (EDI). Thus, polyisocyanate component a) may contain only NDI, only TODI, only EDI, only NDI and TODI, only NDI and EDI, only TODI and EDI and all three polyisocyanates NDI, TODI and EDI. In general, the polyisocyanate component a) contains at least 20% by weight, preferably at least 40% by weight, more preferably at least 50% by weight, more preferably at least 60% by weight, more preferably at least 70% by weight preferably at least 80% by weight, more preferably at least 90% by weight, more preferably at least 95% by weight and particularly preferably at least 99% by weight of these preferred polyisocyanates, based on all the polyisocyanates of the polyisocyanate component which add up to 100% by weight. add.

The polyisocyanate component a) may contain the said polyisocyanates in admixture with further aromatic polyisocyanates. Examples are 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate (M DI), the mixtures of monomeric diphenylmethane diisocyanates and higher nuclear homologues of diphenylmethane diisocyanate (polymer MDI) and 2,4-diphenylmethane diisocyanate. and 2,6-toluene diisocyanate (TDI).

Preferably, the polyisocyanate component a) contains NDI, preferably in amounts of at least 20 wt .-%, based on all polyisocyanates of the polyisocyanate component a), more preferably at least 40 wt .-%, more preferably at least 50 wt .-%, more preferably at least 60 Wt .-%, more preferably at least 70 wt .-%, more preferably at least 80 wt .-%, more preferably at least 90 wt .-%, more preferably at least 95 wt .-% and particularly preferably at least 99 wt .-% of this preferred Polyisocyanates based on all polyisocyanates of the polyisocyanate component which add up to 100 wt .-%.

In a particularly preferred embodiment, pure NDI is used as the polyisocyanate. In a further embodiment of the invention, NDI is mixed with up to 80% by weight, preferably from 0 to 60 wt .-%, in particular 0 to 40 wt .-% of further aromatic polyisocyanates used. Preferred further aromatic polyisocyanates are 2,2-, 2,4- and 4,4-diphenylmethane diisocyanate (MDI), higher-nuclear homologues of diphenylmethane diisocyanate (polymer MDI) and 2,4- and 2,6-toluene diisocyanate (TDI). In further preferred embodiments, the polyisocyanate component contains, instead of NDI, either TODI or EDI or mixtures of TODI and EDI, optionally mixed with up to 80% by weight, preferably 0 to 60% by weight, of further aromatic polyisocyanates.

As isocyanate-reactive compounds b), also mentioned as higher molecular weight compounds with isocyanate-reactive compounds b), well-known polyhydroxy compounds can be used, preferably those having a functionality of 2 to 3. These higher molecular weight compounds with isocyanate-reactive compounds b) also have a number average molecular weight of from 500 g / mol to 6000 g / mol, and preferably from 800 g / mol to 3500 g / mol. Preference is given to using as component b), as relatively high molecular weight compounds having isocyanate-reactive groups, polyether polyols, polyester polyols and / or hydroxyl-containing polycarbonates (polycarbonate polyols).

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 hydrogen atoms bonded to isocyanate groups, or by cationic polymerization with Lewis acids such as antimony pentachloride or borofluoride etherate from one 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 D MC catalysts. The alkylene oxides can be used individually, alternately in succession or as mixtures. Preference is given to mixtures

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 to over

70% primary OH end groups.

The starter molecule is water and di- or trihydric alcohols, such as ethylene glycol, 1, 2 and

1, 3-propanediol, diethylene glycol, dipropylene glycol, 1,4-butanediol, glycerol or trimethylolpropane, preferably ethylene glycol, 1,2- and 1,3-propanediol, diethylene glycol, dipropylene glycol,

Tripropylene glycol and 1, 4-butanediol into consideration.

The polyether polyols, preferably polyoxypropylene-polyoxyethylene polyols, have an average functionality of from 1.7 to 4, particularly preferably from 1.8 to 3, and in particular from 1.9 to 2.5, and number-average molecular weights of from 1000 g / mol to 12000 g / mol, preferably from 1400 g / mol to 8000 g / mol and more preferably from 1700 g / mol to 6000 g / mol. In particular, In particular, the polyether polyols used are those which have been prepared by DMC catalysis, starting from a difunctional initiator.

The polyether polyol used is preferably polytetrahydrofuran. In this case, the functionality is usually from 1.8 to 3, preferably from 1.9 to 2.5 and particularly preferably about 2 and the number average molecular weight is usually 500 g / mol to 4000 g / mol, preferably 750 g / mol to 3000 g / mol, more preferably 800 g / mol to 2500 g / mol.

Polyester polyols can 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. Preferred dicarboxylic acids are succinic, glutaric, adipic, suberic, azelaic, sebacic, decanedicarboxylic, maleic, fumaric, phthalic, isophthalic and terephthalic acids. The dicarboxylic acids are used both individually and in mixture 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 used. Preferably used dicarboxylic acid mixtures of succinic, glutaric and adipic acid in proportions of, for example, 20 to 35: 35 to 50: 20 to 32 parts by weight, and especially adipic acid. Preferred examples of dihydric or polyhydric alcohols, in particular diols, are ethanediol, diethylene glycol, 1,2- or 1,3-propanediol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1, 10-decanediol, glycerol and trimethylolpropane. Ethanediol, diethylene glycol, 1,4-butanediol, 1,5-pentanediol and 1,6-hexanediol are preferably used as the polyhydric alcohols. Also used are polyester polyols from lactones, preferably ε-caprolactone or hydroxycarboxylic acids, preferably ε-hydroxycaproic acid.

For the preparation of the polyester polyols, the organic polycarboxylic acids and / or derivatives and polyhydric alcohols are advantageously polycondensed in the number average molar ratio of 1: 1 to 1, 8, preferably 1: 1, 05 to 1, 2.

The polyesterpolyols obtained preferably have a functionality of from 1.8 to 4, particularly preferably from 1.9 to 3 and in particular from 2.0 to 2.5 and a number average molecular weight of from 500 g / mol to 6000 g / mol, preferably 500 g / mol to 5500 g / mol and in particular 800 g / mol to 5000 g / mol.

Suitable carbonate-containing polyoxyalkylene glycols are, for example, polycondensates of polyoxytetramethylene glycols with alkyl or aryl carbonates or phosgene. In one embodiment of the invention are used as a relatively high molecular weight compound having isocyanate-reactive groups b) mixtures containing polyetherols and polyesterols. In addition to the isocyanate-reactive higher molecular weight compounds b) already described, it is possible to use low molecular weight chain extenders and / or crosslinking agents c). As chain extenders and / or crosslinking agents are used substances having a number average molecular weight of less than 400 g / mol, more preferably from 60 g / mol to 350 g / mol, wherein the chain extender two isocyanate-reactive groups and the crosslinking agent at least 3 isocyanate-reactive groups exhibit. Chain extenders and crosslinkers are used singly or preferably in the form of mixtures. Preference is given to using diols and / or triols having number-average molecular weights of less than 400 g / mol, particularly preferably from 60 g / mol to 300 g / mol and in particular from 60 g / mol to 150 g / mol. Suitable, for example, as chain extenders are aliphatic, cycloaliphatic and / or aromatic 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, glycerol and trimethylolpropane, and low molecular weight hydroxyl-containing polyalkylene oxides based on ethylene and / or 1, 2-propylene oxide and the aforementioned diols and / or triols as starter molecules. However, branched-chain and / or unsaturated alkanediols having usually not more than 12 carbon atoms, such as, for example, 1,2-propanediol, 2-methyl-, 2,2-dimethylpropanediol-1,3,3-butyl-2-ethylpropanediol, are also suitable 1, 3, butene-2-diol-1, 4 and butyne-2-diol-1, 4, diesters of terephthalic acid with glycols having 2 to 4 carbon atoms, such as terephthalic acid bis-ethylene glycol or butanediol-1, 4, hydroxyalkylene ethers of hydroquinone or resorcinol, preferably 1, 4-di- (beta-hydroxyethyl) hydroquinone or 1, 3-di (beta-hydroxyethyl) resorcinol, alkanolamines having 2 to 12 carbon atoms, preferably ethanolamine, 2- Aminopropanol and 3-amino-2,2-dimethylpropanol, N-Alkyldialkanolamine, such as N-methyl and N-ethyldiethanolamine.

Examples of higher-functionality crosslinking agents c) are trifunctional and higher-functional alcohols, such as, for example, Glycerol, trimethylolpropane, pentaerythritol and trihydroxycyclohexanes and trialkanolamines, such as e.g. Called triethanolamine.

As chain extenders it is also possible to use: alkyl-substituted aromatic polyamines having number-average molecular weights, preferably from 122 g / mol to 400 g / mol, in particular primary aromatic diamines having at least one alkyl substituent in the ortho position relative to the amino groups, which has the reactivity of the amino group reduced by steric hindrance, the liquid at room temperature and with the relatively high molecular weight, preferably at least difunctional compounds with isocyanate-reactive groups b) under the processing conditions at least partially, but preferably completely miscible. In the embodiment of the invention, the chain extender is water e). In the inventive use of water as a chain extender, no further chain extenders of the type described above are used. To prepare the moldings of the invention, the technically readily available 1, 3,5-triethyl-2,4-phenylenediamine, 1-methyl-3,5-diethyl-2,4-phenylenediamine, mixtures of 1 - methyl-3,5- diethyl 2,4- and -2,6-phenylenediamine, so-called DETDA, isomer mixtures of 3,3'-di- or 3,3 ', 5,5'-tetraalkyl-substituted 4,4'-diaminodiphenylmethanes having 1 to 4 C Atoms in the alkyl radical, in particular methyl, ethyl and isopropyl radicals having 3, 3 ', 5,5'-tetraalkyl-substituted 4,4'-diaminodiphenylmethanes and mixtures of said tetraalkylsubstituierten 4,4'-diaminodiphenylmethanes and DETDA can be used.

To achieve special mechanical properties, it may also be expedient to use the alkyl-substituted aromatic polyamines in admixture with the abovementioned low molecular weight polyhydric alcohols, preferably dihydric and / or trihydric alcohols or dialkylene glycols.

Preferably, however, no aromatic diamines are used. Preferably, the preparation of the products according to the invention thus takes place in the absence of aromatic diamines.

Suitable solid particles d) are all reinforcing solids. These preferably comprise particles having an average particle diameter of 0.001 μιη to 100 μιη, preferably 0.01 μιη to 50 μιη, more preferably from 0.1 μιη to 10 μιη. The particle size distribution can be monomodal or bimodal or multimodal. Solid particles d) include inorganic and organic solids. As inorganic solids, for example, barium sulfate, calcium sulfate, calcium carbonate, silicates such as fumed silica or silylated silicates can be used. The silylated silicates used are preferably alkylsilylated silicates, the alkyl group (s) preferably having from 1 to 18 carbon atoms. As organic solids, for example, polymer polyetherols, polyurea dispersions, epoxy dispersions, and polyisocyanate polyaddition polyols can be used. Such solids and their preparation is described, for example, in "Mihailonescu, Chemistry and Technology of Polyols for Polyurethanes, Rapra Technology Ltd., 2005, ISBN: 185957-491-2. Other suitable fillers, also referred to as solid particles d), may be mentioned by way of example: inorganic fillers, such as silicate minerals, for example sheet silicates, such as antigorite, bentonite, serpentine, hornblende, amphiboles, chrysotile, calcium carbonate 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 sulfide, zinc sulfide and glass, etc. Preferably used are kaolin (China Clay), aluminum silicate and coprecipitates of barium sulfate and aluminum silicate and natural and synthetic fibrous minerals such Wollastonite, metal and especially glass fibers. dener length, which may be arbitrated if necessary. Suitable organic fillers are, for example: carbon black, melamine, rosin, cyclopentadienyl resins and graft polymers and cellulose fibers, polyamide, polyacrylonitrile, polyurethane, polyester fibers based on aromatic and / or aliphatic dicarboxylic acid esters and in particular carbon fibers.

The inorganic and organic fillers or solid particles d) can be used individually or as mixtures and are advantageously added to the reaction mixture in amounts of 0.5% by weight to 50% by weight, preferably 1% by weight to 40% by weight. %, based on the weight of components a) to c) added.

The solid particles d) preferably have at least one isocyanate-reactive group. The solid particles d) are particularly preferably dispersed in at least one of the higher molecular weight compounds b). If the dispersant is polyetherols or polyesterols in which solid particles of radically polymerized polymers are present as the dispersed phase, this dispersion is also referred to as polymer polyol.

The addition of the solid particles d) in the form of polymer polyols is particularly preferred. In this case, the polymerpolyol contains at least part of the higher molecular weight compound b) in

Form of the dispersant. On the addition of further higher molecular weight compounds with isocyanate-reactive groups b) in addition to the dispersant for the polymer polyol can be completely dispensed with in one embodiment. In general, polymer polyols are known and commercially available. Polymer polyols are prepared by free radical polymerization of the monomers, preferably acrylonitrile, styrene and optionally other monomers, a macromer and optionally a moderator using a radical initiator, usually azo or peroxide compounds, in a polyetherol or polyesterol as a continuous phase. The polyetherol or polyesterol, which is the continuous phase and thus the dispersant, is often referred to as a carrier polyol. The production of polymer polyols is described, for example, in US Pat. No. 4,568,705, US Pat. No. 5,830,944, EP 163,188, EP 365 986, EP 439 755, EP 664 306, EP 622 384, EP 894 812 and WO 00/59971. Suitable carrier polyols are all polyols described under b), these polyols preferably having a functionality of between 2 and 2.3 and particularly preferably a functionality of approximately 2. The statement "approximately 2" takes account of the fact that 2 is the theoretical value, which, however, can never be exactly set in practice, but rather always results in certain fluctuations around the set value 2, depending on the raw materials and dosing accuracy. Macromers, also referred to as stabilizers, are linear or branched polyetherols with number average molecular weights> 1000 g / mol, which contain at least one terminal, reactive ethylenically unsaturated group. The ethylenically unsaturated group can be synthesized by reaction with carboxylic acids such as acrylic acid, carboxylic acid halides such as acrylic acid chloride, carboxylic acid anhydrides such as maleic anhydride, fumaric acid, acrylate and methacrylate derivatives, ethylenically unsaturated epoxides such as 1-vinylcyclohexene-3,4-epoxide, Butadien- monoxide, vinyl glycidyl ether, glycidyl methacrylate and allyl glycidyl ethers and isocyanate derivatives, such as 3-isopropenyl-1, 1 -dimethylbenzylisocyanat and isocyanatoethyl methacrylate, are added to an existing polyol. Another way is to produce a polyol by alkoxydation of propylene oxide and ethylene oxide using starting molecules having hydroxyl groups and an ethylenically unsaturated group. Examples of such macromers are described in US 4,390,645, US 5,364,906, EP 0 461 800, US 4,997,857, US 5,358,984, US 5,990,232, WO 01/04178 and US 6,013,731, incorporated by this reference.

During radical polymerization, the macromers are incorporated into the polymer chain. This forms copolymers with polyether and poly-acrylonitrile-styrene blocks which act as phase mediators in the interface of continuous phase and dispersed phase and suppress the agglomeration of the polymer polyol particles. The proportion of the macromers can be up to more than 90% by weight and is usually from 1% by weight to 60%

Wt .-%, preferably 1 wt .-% to 40 wt .-% and particularly preferably 1 wt .-% to 15 wt .-%, each based on the total weight of the monomers used to prepare the polymer polyol. To prepare polymer polyols, moderators, also referred to as chain transfer agents, are usually used. The moderators reduce the molecular weight of the forming copolymers by chain transfer of the growing radical, thereby reducing cross-linking between the polymer molecules, which affects the viscosity and dispersion stability as well as the filterability of the polymer polyols. The proportion of moderators is usually 0.5 wt .-% to 25 wt .-%, based on the total weight of the monomers used to prepare the polymer polyol. Moderators which are customarily used for the preparation of polymer polyols are alcohols, such as 1-butanol, 2-butanol, isopropanol, ethanol, methanol, cyclohexane, toluene, mercaptans, such as ethanethiol, 1-heptanethiol, 2-octanethiol, 1-dodecanethiol, Thiophenol, 2-ethylhexyl thioglycolates, methyl thioglycolates, cyclohexyl mercaptan and enol ether compounds, morpholines and alpha- (benzoyloxy) styrene. Preferably, alkylmercaptan is used.

To initiate the radical polymerization are usually peroxide or azo compounds such as dibenzoyl peroxides, lauroyl peroxides, t-amyl peroxy-2-ethylhexanoate, di-t-butyl peroxides, diisopropyl peroxide, t-butyl peroxy-2-ethylhexanoate, t-butyl perpivalate, t-Butylperneodecanoat , t-butyl perbenzoate, t-butylpercrotonate, t-butylperisobutyrate, t-butylperoxy-1-methylpropanoate, t-butylperoxy-2-ethylpentanoate, t-butylperoxyoctanoate and di-t-butylper- phthalate, 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile (AIBN), dimethyl 2,2'-azobisisobutyrate, 2,2'-azobis (2-methylbutyronitrile) (AMBN) and 1, 1 'azobis (1 -cyclohexanecar- carbonitrile) used. The proportion of initiators is usually from 0.1% by weight to 6% by weight, based on the total weight of the monomers used to prepare the polymer polyol.

The free-radical polymerization for the preparation of polymer polyols is usually carried out at temperatures of 70 ° C to 150 ° C and a pressure up to 20 bar due to the reaction rate of the monomers and the half life of the initiators. Preferred reaction conditions for the preparation of polymer polyols are temperatures of 80 ° C to 140 ° C at a pressure of atmospheric pressure to 15 bar.

Polymer polyols are produced in continuous processes using continuous feed and drain stirred tanks, stirred tank cascades, tubular reactors and loop reactors with continuous feed and discharge or in batch processes by means of a batch reactor or a semi-batch reactor.

The reaction for producing the polymer polyols can also be carried out in the presence of an inert solvent. Examples of suitable solvents are: benzene, toluene, xylene, acetonitrile, hexane, heptane, dioxane, ethyl acetate, N, N-dimethylformamide and Ν, Ν-dimethylacetamide. Preferred are benzene, xylene and toluene.

For the preparation of the polymer polyol, preference is given to producing a difunctional polyether polyol having predominantly primary OH groups and a number average molecular weight of from 1000 g / mol to 12000 g / mol, preferably from 1400 g / mol to 8000 g / mol, more preferably from 1700 g / mol to 6000 g / mol, used as a carrier polyol.

In a particularly preferred embodiment, a polymer polyol based on polytetrahydrofuran (PTHF), usually having a number-average molecular weight of 500 g / mol to 4000 g / mol, preferably 750 g / mol to 3000 g / mol, particularly preferably 800 g / mol to 2500 g / mol is prepared as a carrier polyol used.

In a further preferred embodiment, a polymer polyol based on a polyester polyol having a number average molecular weight of 480 g / mol to 5000 g / mol, preferably 1000 g / mol to 4500 g / mol and in particular 1600 g / mol to 4500 g / mol , in particular from aliphatic dicarboxylic acids having 2 to 12 carbon atoms, preferably 4 to 6 carbon atoms and diols having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms is used. Suitable ethylenically unsaturated monomers for the preparation of the solids content of the polymer polyol are, for example, butadiene, isoprene, 1,4-pentadiene, 1,6-hexadiene, 1,7-octadiene, styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4 Methylstyrene, 2,4-dimethylstyrene, Ethylstyrene, isopropylstyrene, butylstyrene, phenylstyrene, cyclohexylstyrene and benzylstyrene; substituted styrenes such as cyanostyrene, nitrostyrene, Ν, Ν-dimethylaminostyrene, acetoxystyrene, methyl-4-vinylbenzoate, phenoxystyrene, p-vinylphenyoxide and like derivatives; Acrylates and substituted acrylates such as acrylonitrile, acrylic acid, methacrylic acid, methacrylacrylate, 2-hydroxyethyl acrylate, methyl methacrylate, cyclohexyl methacrylate, benyzyl methacrylate, isopropyl methacrylate, octyl methacrylate, methacrylonitrile, ethyl-alpha-ethoxyacrylate, methyl-alpha-acetaminoacrylates, butyl acrylate, 2-ethylhexyl acrylate , Phenyl acrylate, phenyl methacrylate, acrylamide, N, N-dimethylacrylamide, Ν, Ν-dibenzylacrylamide, N-butylacrylamide and methacryloylformamide; Vinyl esters, vinyl ethers, vinyl ketones, etc., such as vinyl acetate, vinyl butyrate, isopropenyl acetate, vinyl formate, vinyl acrylate, vinyl methacrylate, vinyl methoxyacetate, vinyl benzoate, vinyltoluene, vinylnaphthalene, vinyl methyl ether, vinyl propyl ether, vinyl butyl ether, vinyl 2-ethylhexyl ether, vinyl phenyl ether, vinyl -2-methoxyethyl ether, methoxybutadiene, vinyl-2-butoxyethyl ether, 2,4-dihydro-1,2-pyran, 2-butoxy-2'-vinyloxydiethyl ether, vinyl methyl ketone, vinyl ethyl ketone, vinyl phenyl ketone, vinyl ethyl sulfone, N-methyl-N- vinylacetamide, N-vinylpyrrolidone, vinylimidazole, dinvinylsulfoxide, divinylsulfone, sodium vinylsulfonate, methylvinylsulfonate, N-vinylpyrrole and vinylphosphonate; Dimethylfu marat, dimethyl maleate, maleic acid, crotonic acid, fumaric acid, itaconic acid, monomethylitaconate, t-butylaminoethyl methacrylate, dimethylaminoethyl methacrylate, glycidyl acrylate, allyl alcohol, glycol monoesters of itaconic acid and vinylpyridine. Preferred ethylenically unsaturated monomers are styrene, acrylonitrile, acrylates and acrylamides.

In a particularly preferred embodiment, acrylonitrile is used as the unsaturated monomer. Preferably, a macromer is further added to the polymerization. Optionally, the polymerization is further carried out using a moderator and using a radical initiator.

Polymer polyols based on acrylonitrile can be thermally postcrosslinked by heating to temperatures above 120 ° C. In a particularly preferred embodiment, the polymer polyols containing polyacrylonitrile are thermally postcrosslinked. In a preferred embodiment, the solids content contains acrylonitrile and macromer, the proportion of macromer being from 1% by weight to 10% by weight, preferably from 3% by weight to 6% by weight, based on the total weight of the solids content of the polymer polyol, is.

In a preferred embodiment, the polymer polyol has a solids content of 25 wt .-% to 90 wt .-%, more preferably 30 wt .-% to 60 wt .-% and in particular 35 wt .-% to 55 wt .-%, based on the total weight of the polymer polyol, on.

The solids content of polymer polyols is calculated from the percentage ratio of the monomers used and the macromers to the carrier polyols used and is usually determined gravimetrically on the finished polymer polyol from the percentage ratio of the solid mass to the total mass of the polymer polyol. The solids content, based on the total weight of the components a) to h) is at least 10 wt .-%. The solids content is preferably from 20% by weight to 90% by weight, particularly preferably from 15% by weight to 70% by weight, in each case based on the total weight of components a) to h). It is also possible to use mixtures of different solid particles d).

According to the invention, the preparation of the cellular polyisocyanate polyaddition products is carried out in the presence of water e). The water acts both as crosslinker and / or chain extender to form urea groups as well as due to the reaction with isocyanate groups to form carbon dioxide as blowing agent. The content of water is generally from 0.01 wt .-% to 5 wt .-%, preferably 0.3 wt .-% to 3 wt .-%, more preferably 0.5 wt .-% to 1, 5 Wt .-%, more preferably 0.7 wt .-% to 1, 0 wt .-% and particularly preferably 0.8 wt .-% to 0.9 wt .-% based on the total weight of components a) to h ).

In addition to water, in the preparation of the cellular polyisocyanate polyaddition products as blowing agent f) additionally generally known chemically and / or physically acting blowing agents can be used. Chemical blowing agents are compounds which form gaseous products by reaction with isocyanate. These include, for example, water or formic acid. Physical blowing agents are understood as meaning compounds which are dissolved or emulsified in the starting materials of polyurethane production and which evaporate or give off gas under the conditions of polyurethane formation. These are, for example, hydrocarbons, halogenated hydrocarbons and other compounds, for example perfluorinated alkanes such as perfluorohexane, chlorofluorocarbons, ethers, esters, ketones and / or acetals, for example (cyclo) aliphatic hydrocarbons having 4 to 8 carbon atoms, or fluorohydrocarbons such as solkanes ^® 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 being used as the sole blowing agent. If no water is used as blowing agent, preferably only physical blowing agents are used. In one embodiment, the propellant f) is encapsulated, preferably added micro-encapsulated.

As catalysts g) for the preparation of the polyurethane foams compounds are preferably used which greatly accelerate the reaction of the hydroxyl-containing compounds of component b) and optionally component c) with the 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, Ν, Ν, Ν ', Ν'-tetramethylethylenediamine, Ν, Ν, Ν', Ν'-tetramethylbutanediamine, Ν, Ν, Ν ', Ν'-tetramethylhexanediamine, pentamethyldiethylenetriamine, tetramethyldiaminoethyl 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 di- methylethanolamine. Also 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 also bismuth carboxylates such as bismuth (III) neodecanoate, bismuth 2-ethylhexanoate and bismuth octanoate or mixtures thereof , Also suitable are titanium and zinc-based catalysts, such as titanium (IV) bis (ethylacetoacetato) diisopropoxide, titanium (IV) diisopropoxide bis (2,4-pentanedionate), titanium (IV) triisopropoxide (2,4-pentanedionate). , Ethoxybis (pentane-2,4-dionato-0,0 ') (propan-2-olato) titanium, titanium (IV) oxide acetylacetonate, bis (diacetylacetonato) titanium (IV) butoxide-isopropoxide, bis (diacetylacetonato ) titanium (IV) ethoxide isopropoxide) and saturated or unsaturated, aliphatic or alicyclic and aromatic carboxylates of zinc, such as (II) naphthenate, zinc (II) decanoate, zinc (II) butyrate, such as zinc (II) -4 cyclohexyl butyrate, zinc (II) neodecanoate, zinc (II) isobutyrate, zinc (II) benzoate, and zinc (II) bis-2,2,6,6-tetramethyl-3,5-heptanedionate and Zinc (II) p-toluenesulfonate be used. Zinc (II) octoate and zinc (II) 2-ethylhexanoate are particularly preferably used. In this case, titanium and zinc-based catalysts are preferably used in combination with one another. Such combinations are described for example in EP 1736489, incorporated by reference. The organic metal compounds can be used alone or preferably in combination with strongly basic amines. If component b) is an ester, only amine catalysts are preferably used.

Preferably used are 0.001 wt .-% to 5 wt .-%, in particular 0.05 wt .-% to 2 wt .-% catalyst or catalyst combination, based on the weight of component b).

If appropriate, auxiliaries and / or additives h) may also be added to the reaction mixture for the preparation of the polyurethane foams. Mention may be made, for example, of surface-active substances, foam stabilizers, cell regulators, release agents, fillers, dyes, pigments, hydrolysis protectants, odor-absorbing substances, perfumes and fungistatic and / or bacteriostatic substances.

As surface-active substances z. 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 salts of fatty acids with amines, for example diethylamine, stearic diethanolamine, 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, turkey 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 with polyols are also suitable. xyalkylen- and Fluoralkanresten as side groups. The surface-active substances are usually used in amounts of from 0.01 parts by weight to 5 parts by weight, based on 100 parts by weight of component b) and optionally of component c). Examples of suitable release agents are: reaction products of fatty acid esters with polyisocyanates, salts of polysiloxanes containing amino groups 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 acid 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 number average molecular weights of 60 g / mol to 400 g / mol, such as For example, EP 153 639 discloses mixtures of organic amines, metal salts of stearic acid and organic mono- and / or dicarboxylic acids or their anhydrides, as disclosed, for example, in DE-A-3 607 447, or mixtures of an imino compound, the metal salt of one Carboxylic acid and given If a carboxylic acid, as disclosed for example in US 4,764,537. The publications mentioned are part of this application.

The production of the moldings is advantageously carried out at an isocyanate to hydroxyl group ratio (NCO / OH ratio) of 0.75 to 1.50, wherein the heated starting components mixed and in an amount corresponding to the desired molding density in a heated, preferably tightly closing mold to be brought. The surface temperature of the inner wall of the mold is 60 ° C to 100 ° C according to the invention. The moldings are cured after 10 minutes to 60 minutes and thus demoulded.

The amount of the introduced into the mold reaction mixture is usually measured so that the resulting moldings have the density already shown. The starting components are usually introduced at a temperature of 15 ° C to 120 ° C, preferably from 30 ° C to 1 10 ° C, in the mold. The degrees of compaction for the production of the shaped bodies are between 1, 1 and 8, preferably between 2 and 6.

The inventive production of the shaped bodies preferably takes place in a two-stage process by preparing a prepolymer containing isocyanate groups in the first stage by reacting component a) with component b) and component d) and carrying this prepolymer in a mold in the second stage a crosslinker component comprising component c) and component e), and optionally component f), component g) and / or component h) are present in the prepolymer and / or the crosslinker component. When using a mixing chamber with multiple feed nozzles, the starting components can be fed individually and mixed intensively in the mixing chamber. It has proven to be advantageous to work according to the two-component method. According to a particularly advantageous embodiment, an NCO-group-containing prepolymer is first prepared in a two-stage process. For this purpose, the components b) and component d) are reacted with component a) in excess, usually at temperatures of 80 ^° C to 160 ^° C, preferably from 1 10 ^° C to 150 ^° C, reacted. The reaction time is based on the achievement of the theoretical NCO content, ie it is considered complete when only as many isocyanate groups can be measured as in the reaction of molecular amounts or components a), d) and b) remain.

The auxiliaries and / or additives h) are preferably contained in the crosslinker component. As auxiliaries and additives h), at least one generally known carbodiimide is used as hydrolysis protection in the crosslinking component, for example 2,2 ', 6,6'-tetraisopropyldiphenylcarbodiimide.

To improve the demoulding of the moldings produced according to the invention, it has proved to be advantageous to coat the mold interior surfaces at least at the beginning of a production series with conventional external mold release agents, for example based on wax or silicone or in particular with aqueous soap solutions.

The mold life is an average of 10 minutes to 60 minutes, depending on the size and geometry of the molded part.

After the moldings have been produced in the mold, the moldings may preferably be tempered for a period of 1 hour to 48 hours at temperatures of usually from 70 ° C to 120 ° C. There are obtained moldings having a tensile strength according to DIN 53571 of> 3.5 N / mm ² , preferably 4 N / mm ² to 5.8 N / mm ² , an elongation according to DIN 53571 of> 350%, preferably 410% to 500 % and a tear strength according to DIN 53515 of> 12 N / mm, preferably 13 N / mm to 19 N / mm and in particular a compression set, which is determined by storage at 80 ^° C for 22 h, then compression of the test specimens by 40% and Determine the missing residual level after relaxing (on the basis of DIN 53572), of less than 25%, preferably 10% to 23%.

Use find the inventive cell polyisocyanate polyaddition products, hereinafter referred to as "moldings", as damping elements in motor vehicle, eg as additional springs, bump stop, wishbone, Hinterachsfahrschemellager, stabilizer, Längsstrebenlager, suspension strut, shock absorber bearings, bearings for wishbones or as befindlichem on the rim Notrad, which, for example, is involved in puncture acts to drive the vehicle on the cellular polyisocyanate polyaddition product and remain controllable.

The cell polyisocyanate polyaddition products according to the invention continue to be used for the production of damping elements for electric motors, household appliances, for sports & leisure, in shipping, in elevator construction and in earthquake protection.

The invention is further illustrated by the following examples. Examples

Synthesis of solid-filled polyols

Starting materials:

Polyol 1 polyester polyol based on adipic acid and monoethylene glycol with an OH number of 56;

Polyol 2 polyester polyol based on adipic acid and 1, 4-butanediol with a

OH number of 1 10;

Polyol macromer: Branched polyetherol based on propylene oxide and ethylene oxide having a functionality of 6 and an OH number of 18, which has been functionalized to introduce a polymerisable unit with dimethyl meta-isopropenyl benzyl isocyanate (TM I);

Initiator: 2,2-azobisisobutyronitrile.

example 1

Preparation of Poly (Acrylonitrile) Particles-filled Polyol

In a 4-liter glass flask equipped with a reflux condenser and a mechanical stirrer and preheated to 80 ° C., 1900 g of molten polyol 1 and 7.5 g of polyol macromer together with 200 ml of toluene and 100 g Submitted to acrylonitrile and the reaction mixture heated to 100 ° C. As soon as the reaction temperature has been reached, another 1.5 g and, after a reaction time of 120 minutes, an additional 0.75 g of the azo initiator are added and the mixture is stirred for 120 minutes in order to complete the polymerization. Subsequently, unreacted acrylonitrile and the solvent are removed by vacuum distillation (<0.1 mbar) at 1 10 ° C from the reaction product.

Example 2 Preparation of Poly (Acrylonitrile) Particles-filled Polyol

In a 4-liter glass flask equipped with a reflux condenser and a mechanical stirrer and was preheated to 80 ° C, 1700 g of molten polyol 2 and 22.5 g Polyolmakromer together with 300 ml of toluene and 200 g of acrylonitrile are introduced with stirring and the reaction mixture is heated to 100 ° C. As soon as the reaction temperature has been reached, 4.5 g and, after a reaction time of 120 minutes, an additional 2.25 g of the azo initiator are added first and the mixture is stirred for 120 minutes in order to complete the polymerization. Subsequently, unreacted acrylonitrile and the solvent are removed by vacuum distillation (<0.1 mbar) at 1 10 ° C from the reaction product.

Example 3 Preparation of a poly (styrene) -co-poly (acrylonitrile) nanoparticle-filled polyol

In a 4-liter glass flask equipped with a reflux condenser and a mechanical stirrer, 1746 g of molten polyol 1 are submitted together with 500 g of polyol and 200 mL toluene and heated to 100 ° C in a nitrogen atmosphere. While stirring the reaction mixture kept at the reaction temperature, a mixture of 167 g of styrene, 83 g of acrylonitrile and 2.6 g of dodecanethiol and within 160 minutes a solution of 1.2 g of azo initiator in 200 g of toluene are added within 150 minutes , After completion of the metering, the reaction mixture is stirred for a further 30 minutes. Subsequently, the temperature is increased to 1 10 ° C and unreacted monomer and the solvent are distilled off in vacuo (<0.1 mbar).

Example 4

Preparation of a poly (styrene) -co-poly (acrylonitrile) nanoparticles filled polyol

In a 4-liter glass flask equipped with a reflux condenser and a mechanical stirrer, 1746 g of molten polyol 1 are submitted together with 500 g of polyol and 200 mL toluene and heated to 100 ° C in a nitrogen atmosphere. While stirring the reaction mixture held at reaction temperature, a mixture of 62.5 g of styrene, 187.5 g of acrylonitrile and 2.6 g of dodecanethiol and within 160 minutes a solution of 1, 2 g of azo initiator in 200 g Toluene added. After completion of the metering, the reaction mixture is stirred for a further 30 minutes. Subsequently, the temperature is increased to 1 10 ° C and unreacted monomer and the solvent in a vacuum (<0.1 mbar) distilled off. Example 5

Preparation of a poly (acrylonitrile) nanoparticle filled polyol

In a 4-liter glass flask equipped with a reflux condenser and a mechanical stirrer, 1746 g of molten polyol 1 are introduced together with 500 g of polyol and 200 mL of toluene and heated to 100 ° C in a nitrogen atmosphere. While the reaction mixture is maintained at reaction temperature, a mixture of 250 g of acrylonitrile and 2.6 g of dodecanethiol and within 160 minutes a solution of 1.2 g of azo initiator in 200 g of toluene are added within 150 minutes. After completion of the metering, the reaction mixture is stirred for a further 30 minutes. Subsequently, the temperature is increased to 1 10 ° C and unreacted monomer and the solvent in a vacuum (<0.1 mbar) distilled off. Production of polyurethane foams

raw materials

Crosslinking component: water-based standard crosslinker mixture of water, catalyst,

Co-catalyst, stabilizer and mold release agent, which has a water content of 35.9 wt .-%, based on the total crosslinking component.

Isocyanate 1: Prepolymer of 19.4 parts by weight of 1, 5-NDI and 80.6 parts by weight of polyol 1 with an NCO content of 4-5%.

Isocyanate 2: Prepolymer of 18.6 parts by weight of 1, 5-NDI and 49.6 parts by weight of polyol 1 and 31, 7 parts by weight of solids-filled polyol from Example 1 with an NCO content of 4-5% , Isocyanate 3: Prepolymer of 20.3 parts by weight of 1, 5-NDI and 59.5 parts by weight of polyol 1 and 20.2 parts by weight of solids-filled polyol from Example 2 having an NCO content of 3.5 - 5%.

Prepolymer of 17.8 parts by weight of 1, 5-NDI and 63.7 parts by weight of polyol 1 and 18.6 parts by weight of solids-filled polyol from Example 3 with an NCO content of 4-5%.

Isocyanate 5: prepolymer of 18.5 parts by weight of 1, 5-NDI and 75.0 parts by weight of polyol 1 and 6.5 parts by weight of solids-filled polyol from Example 5 with an NCO content of 4-5% , Example 6

Reaction Mixture 1 (comparative): 450 parts by weight of isocyanate 1 (90 ° C.) and 10.26 parts by weight of the crosslinking component (50 ° C.) are mixed together, the mixture is poured into a block mold (1 × 10 10 × 210 × 30) mm) and the block removed at 90 ° C after 20 minutes.

In addition, moldings are made of microcellular foam. The produced parts are post-annealed at 100 ° C for 48 hours.

Example 7

Reaction mixture 2 (according to the invention):

450 parts by weight of isocyanate 2 (90 ° C) and 10.26 parts by weight of the crosslinking component (50 ° C) are mixed together, the mixture is placed in a block mold (1 10 x 210 x 30 mm) and the block demolded at 90 ° C after 30 minutes. In addition, moldings are made of microcellular foam. The produced parts are post-annealed at 100 ° C for 48 hours.

Example 8 Reaction Mixture 3 (Inventive):

450 parts by weight of isocyanate 3 (90 ° C) and 9.86 parts by weight of the crosslinking component (50 ° C) are mixed together, the mixture is placed in a block mold (1 10 x 210 x 30 mm) and the block demolded at 90 ° C after 20 minutes.

Example 9

Reaction mixture 4 (according to the invention):

450 parts by weight of isocyanate 4 (90 ° C.) and 10.06 parts by weight of the crosslinking component (50 ° C.) are mixed together, the mixture is poured into a block mold (1 × 10 × 210 × 30 mm) and the block is removed from the mold at 90 ° C. after 20 minutes. In addition, moldings are made of microcellular foam. The produced parts are post-annealed at 100 ° C for 48 hours.

Example 10

Reaction mixture 5 (according to the invention):

450 parts by weight of isocyanate 5 (90 ° C.) and 11.00 parts by weight of the crosslinking component (50 ° C.) are mixed together and the mixture is poured into a block mold (1 × 10 × 210 × 30 mm) and the block removed from the mold at 90 ° C after 20 minutes.

In addition, moldings are made of microcellular foam. The produced parts are post-annealed at 100 ° C for 48 hours. The dynamic resistance (Hydropulser test) and the static mechanical properties of the molded articles produced are determined after 24 hours storage according to DIN 53571 and 53515 and are listed in Table 1.

To determine the dynamic resistance with the help of hydro-pulpers, a shaped body is clamped in the hydropulser. 100,000 load changes (1, 2Hz) are performed at 7kN without cooling. If the molded article withstands 100,000 load changes, the test is passed.

The results of the tests are summarized in Table 1.

Table 1

Table 1 shows that the test specimens prepared from the reaction mixtures 2 to 5 according to the invention consist of the dynamic loading of the Hydropulser test. The mechanical properties such as tensile strength, elongation at break and tear strength are improved over the samples of the reaction mixture 1. Thus, moldings of the reaction mixtures 2 to 5 according to the invention allow for increased stress.

Claims

21

claims

1 . Cellular polyisocyanate polyaddition product obtainable by mixing

Polyisocyanates containing at least one polyisocyanate selected from the group consisting of 1, 5-naphthylene diisocyanate (NDI), ditolyl diisocyanate (TODI) and diphenylethane diisocyanate (EDI),

relatively high molecular weight compounds with isocyanate-reactive groups,

optionally crosslinking agents,

Solid particles,

Water,

optional catalysts,

optional propellant,

optionally other additives, to a reaction mixture and reacting the reaction mixture.

Cellular polyisocyanate polyaddition product according to claim 1, characterized in that it contains as solid particles d) inorganic fillers.

Cellular polyisocyanate polyaddition product according to claim 1, characterized in that it contains as solid particles d) polymers prepared by free-radical polymerization.

Cellular polyisocyanate polyaddition product according to claim 3, characterized in that it contains as solid particles d) homopolymers or copolymers of styrene, acrylonitrile, acrylates and acrylamides.

Cellular polyisocyanate polyaddition product according to claim 4, characterized in that it contains as solid particles d) homopolymers of polyacrylonitrile.

Cellular polyisocyanate polyaddition product according to one of claims 3 to 5, characterized in that the solid particles d) are added in the form of polymer polyol which contains the polymers dispersed in a carrier polyol.

7. Zelliges polyisocyanate polyaddition product according to claim 6, characterized in that the carrier polyol is a polyester polyol. 22

8. Cellular polyisocyanate polyaddition product according to claim 6, characterized in that the carrier polyol is a polyether polyol.

9. Cellular polyisocyanate polyaddition product according to claim 6, characterized in that the carrier polyol is a mixture of polyester polyol and polyether polyol.

10. Zelliges polyisocyanate polyaddition product according to one of claims 6 to 9, characterized in that the carrier polyol has a functionality of 2.

1 1. Cellular polyisocyanate polyaddition product according to one of claims 1 to 10, characterized in that the polyisocyanates a) contain further aromatic polyisocyanates. 12. Zelliges polyisocyanate polyaddition product according to any one of claims 1 to 1 1, characterized in that the polyisocyanates contain a) at least 20 wt .-% 1, 5-naphthylene diisocyanate (NDI).

13: Cellular polyisocyanate polyaddition product according to one of claims 1 to 12, characterized in that the content of water 0.01 wt .-% to 5 wt .-% based on the total weight of components a) to h).

14. Use of cellular polyisocyanate polyaddition products, as defined in any one of claims 1 to 13, for the preparation of damping elements.