WO2011070153A2

WO2011070153A2 - Dimensionally stable polyurethane molded foam bodies

Info

Publication number: WO2011070153A2
Application number: PCT/EP2010/069376
Authority: WO
Inventors: Andre Kamm; Michele Lorusso; Erhan Cubukcu
Original assignee: Basf Se
Priority date: 2009-12-11
Filing date: 2010-12-10
Publication date: 2011-06-16
Also published as: PT2510028E; BR112012013911A2; CN102666625B; ES2544886T3; JP5654038B2; WO2011070153A3; EP2510028B1; CN102666625A; JP2013513684A; KR20120103684A; BR112012013911B1; EP2510028A2

Abstract

The invention relates to a method for producing polyurethane molded foam bodies, wherein a) organic polyisocyanates are mixed with b) polyols, containing b1) polyesterols and b2) polymer polyetherols having a fraction of primary OH groups of less than 50%, c) expanding agents, and optionally d) chain lengthening agents and/or cross-linking agents, e) catalysts and f) other auxiliary agents and/or additives, to form a reaction mixture, introduced in a mold and allowed to fully cure to form a polyurethane molded foam body. The invention further relates to the use of polymer polyetherols and polymer polyesterols for producing polyurethane molded foam bodies and to the use of such polyurethane molded foam bodies as a shoe sole.

Description

Description: The present invention relates to a process for the preparation of polyurethane foam moldings in which a) organic polyisocyanates having b) polyols containing b1) polyesterols and b2) polymer polyetherols having a primary OH content of less than 50%, c) blowing agents, and optionally d) chain extenders and / or crosslinking agents, e) catalysts and f) other auxiliaries and / or additives, mixed into a reaction mixture, placed in a mold and allowed to react to form a polyurethane foam molding. Furthermore, the present invention relates to the use of polymer polyetherols and polymer polyesterols for the production of polyurethane foam moldings and the use of such polyurethane foam moldings as a shoe sole.

There has been a trend towards lighter shoe soles in recent years. The reduction in the density of polyurethane shoe soles, however, leads to problems with the dimensional stability of the moldings. This means that the entire sole becomes smaller or the surface quality of the shoe soles suffers from shrunken areas.

In order to improve the dimensional stability of the polyurethanes, various possibilities are discussed in the literature. For example, DE 2402734 describes the preparation of integral polyurethane foams in which a prepolymer based on polyesterol is mixed with a polyol component based on polyetherols. A disadvantage of polyurethane systems produced in this way is that the incompatibility of the polyester and polyetherols suffers from the mechanical properties and shrinkage of the integral polyurethane foams can not be prevented. Another possibility described in the literature is the use of graft or polymer polyols. Thus, EP 1 042 384 describes the preparation of low-density, dimensionally stable soles based on polyetherol by the use of large amounts of polyether graft polyols. Disadvantages of this process are the markedly poorer mechanical properties in comparison with polyester sol-based shoe soles. Furthermore, the high proportion of polymer polyetherols has a disadvantage on the viscosity of the polyol component.

EP 1 790 675 and EP 1 756 187 describe the use of polymer polyols based on polyesterols in a polyester polyurethane. Due to the higher viscosity of the large amounts of polyester polymer polyol, these systems are much more difficult to process. Further, EP 1 790 675 and EP 1 756 187 disclose the use of polyetherol-based polymer polyols in polyesterol polyurethane system. The writings show in the comparative example that he use of Polymerpolyetherolen leads to an integral foam with insufficient surface and coarse cell structure.

Object of the present invention was to provide a polyurethane foam molding, in particular a polyurethane integral foam, which does not shrink even in density ranges of less than 500 g / L and has an excellent surface finish.

This object is achieved by a polyurethane foam molding obtainable by a process comprising a) organic polyisocyanates with b) polyols containing b1) polyesterols and b2) polymer polyetherols having a proportion of primary OH groups of less than 50%, c) blowing agents, and optionally d) chain extenders and / or crosslinking agents, e) catalysts and f) other auxiliaries and / or additives, mixed into a reaction mixture, placed in a mold and allowed to react to form a polyurethane moldings.

Polyurethane foam moldings in the context of the invention are polyurethane foams which are produced in a mold. Polyurethane integral foams in the context of the invention are polyurethane foams according to DIN 7726 with a marginal zone, which due to the shaping process has a higher density than the core understood. The total raw density averaged over the core and the edge zone is preferably above 80 g / L to 500 g / L, more preferably from 150 g / L to 450 g / L. Since integral polyurethane foams are also produced in one mold, polyurethane foam moldings also include polyurethane integral foams.

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

Preferably, 4,4'-MDI is used. The preferred 4,4'-MDI can contain from 0 to 20% by weight of 2,4'-MDI and small amounts, to about 10% by weight, of allophanate- or uro-amino-modified polyisocyanates. It is also possible to use small amounts of polyphenylene polymethylene polyisocyanate (polymeric MDI). The total amount of these high-functionality polyisocyanates should not exceed 5% by weight of the isocyanate used. The polyisocyanate component (a) is preferably used in the form of polyisocyanate prepolymers. These polyisocyanate prepolymers are obtainable by reacting polyisocyanates (a-1) described above, for example at temperatures of 30 to 100 ° C., preferably at about 80 ° C., with polyols (a-2) to give the prepolymer.

Polyols (a-2) are known to the person skilled in the art and described, for example, in "Kunststoffhandbuch, Volume 7, Polyurethanes", Carl Hanser Verlag, 3rd edition 1993, Chapter 3.1. The polyols (a-2) used are preferably the polyesterols described under b1).

If appropriate, customary chain extenders or crosslinking agents are added to the said polyols in the preparation of the isocyanate prepolymers. Such substances are described below under d).

Polyols b) contain polyesterols b1) and polymer polyetherols b2) with a proportion of primary OH groups of less than 50% and optionally polymer polyesterols b3) and / or further polyols, for example polyetherols b4).

As polyester b1) polyesterols commonly used in polyurethane chemistry can be used. Polyesterols b1) 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 and polyhydric alcohols, preferably diols having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms. Suitable dicarboxylic acids are, for example: succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid and terephthalic acid. The dicarboxylic acids can be used both individually and as a mixture with one another. Instead of the free dicarboxylic acids, it is also possible to use the corresponding dicarboxylic acid derivatives, for example dicarboxylic acid esters of alcohols having 1 to 4 carbon atoms or dicarboxylic acid anhydrides. 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 in particular adipic acid. Examples of dihydric and polyhydric alcohols, especially diols, are: ethanediol, diethylene glycol, 1,2- or 1,3-propanediol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1, 10 Decanediol, glycerol and trimethylolpropane. Preferably used are ethanediol, diethylene glycol, 1, 4-butanediol, 1, 5-pentanediol and 1, 6-hexanediol. It is also possible to use polyester polyols from lactones, for example ε-caprolactone or hydroxycarboxylic acids, for example ω-hydroxycaproic acid. For the preparation of the polyester polyols, the organic, for example aromatic and preferably aliphatic polycarboxylic acids and / or derivatives and polyhydric alcohols catalyst-free or preferably in the presence of esterification catalysts, conveniently in an atmosphere of inert gas, such as nitrogen, carbon monoxide, helium, argon, inter alia the melt at temperatures of 150 to 250 ° C, preferably 180 to 220 ° C, optionally under reduced pressure, to the desired acid number, which is preferably less than 10, more preferably less than 2, polycondensed. According to a preferred embodiment, the esterification mixture at the abovementioned temperatures up to an acid number of 80 to 30, preferably 40 to 30, under normal pressure and then under a pressure of less than 500 mbar, preferably 50 to 150 mbar, polycondensed. Suitable esterification catalysts are, for example, 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 entrainers, such as benzene, toluene, xylene or chlorobenzene for the azeotropic distillation of the condensation water. For the preparation of the polyester polyols, the organic polycarboxylic acids and / or derivatives and polyhydric alcohols are advantageously polycondensed in a molar ratio of 1: 1 to 1, 8, preferably 1: 1, 05 to 1, 2 polycondensed.

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

In addition to polyesterols b1), it is also possible to use further polyols, for example polyetherphenyl b4). As polyetherols b4) it is possible to use all polyetherols customarily used in polyurethane chemistry. Polyetherols b4) can be 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 which contains 2 to 3 reactive hydrogen atoms bonded or by cationic polymerization with Lewis acids, such as antimony pentane. tachloride 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. Furthermore, it is also possible to use as catalysts multimetal cyanide compounds, so-called DMC catalysts. The alkylene oxides can be used individually, alternately in succession or as mixtures. Preference is given to mixtures of 1, 2-propylene oxide and ethylene oxide. Suitable starter molecule are water or dihydric and trihydric alcohols, such as ethylene glycol, 1, 2- and 1, 3-propanediol, diethylene glycol, dipropylene glycol, 1, 4-butanediol, glycerol or trimethylolpropane into consideration. The polyether polyols, preferably polyoxypropylene polyoxyethylene polyols, preferably have a functionality of from 2 to 3 and number average molecular weights of from 1, 000 to 8,000, preferably from 2,000 to 6,000, g / mol. Preferably, based on the weight of the polyesterol b1), less than 50 wt .-%, more preferably less than 20%, most preferably less than 5 wt .-% and in particular no polyetherol used.

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 further monomers, a macromer and, if appropriate, a moderator using a free-radical initiator, usually azo or peroxide compounds, in a polyetherol or polyesterol as the continuous phase. In this case, polymer polyols which have been prepared in a polyetherol as the continuous phase are referred to as polymer polyetherols and polymer polyols which have been prepared in a polyesterol as continuous phase, as Polymerpolyestero- le b3). The polyetherol or polyesterol, which is the continuous phase and thus the dispersant, is often referred to as a carrier polyol. Exemplary of the preparation of polymer polyols are the patents US 4568705, US 5830944, EP 163188, EP 365986, EP 439755, EP 664306,

EP 622384, EP 894812 and WO 00/59971.

This is usually an in situ polymerization of acrylonitrile, styrene or preferably mixtures of styrene and acrylonitrile, for example in a weight ratio of 90:10 to 10:90, preferably 70:30 to 30:70. Suitable carrier polyols are all polyols described under b1) and b4). The polyetherols for the preparation of the polymer polyetherols have a content of primary OH groups of less than 50% by weight, more preferably less than 30% and in particular less than 10%. Macromers, also referred to as stabilizers, are linear or branched polyetherols or polyester polyols having molecular weights> 1000 g / mol and containing 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 acryloyl chloride, carboxylic acid anhydrides such as maleic anhydride, fumaric acid, acrylate and methacrylate derivatives, ethylenically unsaturated epoxides such as 1-vinylcyclohexene-3, 4-epoxide, 1-butadiene monoxide, vinyl glycidyl ether, glycidyl methacrylate and allyl glycidyl ether and isocyanate derivatives, such as 3-iso propenyl 1, 1-dimethylbenzyl isocyanate, isocyanato-ethyl methacrylate, are added to an already existing polyol. Another approach is the preparation of a polyol by alkoxydation of propylene oxide and ethylene oxide using starting molecules having hydroxyl groups and ethylenic unsaturation. Examples of such macromers are described in US 4390645, US 5364906, EP 0461800, US 4997857, US 5358984, US 5990232, WO 01/04178 and US 6013731.

During radical polymerization, the macromers are incorporated into the polymer chain. This forms copolymers with polyether or polyester and a 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 macromers can be up to more than 90% by weight and is usually from 1 to 60% by weight, preferably from 1 to 40% by weight and more preferably from 1 to 15% by weight, based in each case 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 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, methylthio glycolates, cyclohexyl mercaptan and enol ether compounds, morpholines and α- (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-ethyl hexanoates, di-t-butyl peroxides, diisopropyl peroxide carbonate, t-butyl peroxy-2-ethyl hexanoates, t-butyl perpivalates, t-butyl perneo decanoates, t-butyl perbenzoates, t-butyl percrotonates, t-butyl perisobutyrates, t-butyl peroxy-1-methylpropanoates, t-butyl peroxy-2-ethyl pentanoates, t-butyl peroxyoctanoates and di-t-butyl butyl perphthalate, 2,2'-azobis (2,4-dimethyl-valeronitrile), 2,2'-azobisisobutyronitrile (AI BN), dimethyl-2,2'-azobisisobutyrate, 2,2'-azobis (2-methylbutyronitrile ) (AMBN), 1,1'-azobis (1-cyclohexane-carbonitrile). The proportion of initiators is usually 0.1 to 6 wt .-%, based on the total weight of the monomers used to prepare the polymer polyol. The radical polymerization for the preparation of polymer polyols is usually carried out at temperatures of 70 to 150 ° C and a pressure of 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 to 140 ° C at a pressure of atmospheric pressure to 15 bar.

Polymer polyols are made in continuous processes using continuous feed and off-stream stirred tanks, stirred tank cascades, tubular reactors and loop reactors with continuous feed and drain, 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. The following solvents may be used for example: benzene, toluene, xylene, acetonitrile, hexane, heptane, dioxane, ethyl acetate, N, N-dimethylformamide, Ν, Ν-dimethylacetamide, etc. Preference is given to benzene, xylene and toluene.

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, alpha-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4 - Methylstyrene, 2,4-dimethylstyrene, ethylstyrene, I so propyl styrene, butylstyrene, phenylstyrene, cyclohexylstyrene, benzylstyrene and similar derivatives; substituted styrenes such as cyanostyrene, nitrostyrene, Ν, Ν-dimethylaminostyrene, acetoxystyrene, methyl 4-vinylbenzoate, phenoxystyrene, p-vinylphenyoxide and similar derivatives; Acrylates and substituted acrylates such as acrylonitrile, acrylic acid, methacrylic acid, methacrylic acrylate, 2-hydroxyethyl acrylate, methyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, isopropyl methacrylate, octyl methacrylate, methacrylonitrile, ethyl-alpha-ethoxy acrylate, methyl-alpha-aceto-amino acrylate, butyl acrylate, 2 Ethylhexyl acrylate, phenyl acrylate, phenyl methacrylate, acrylamide, N, N-dimethylacrylamide, Ν, Ν-dibenzylacrylamide, N-butylacrylamide, methacryloylformamide and like derivatives; Vinyl esters, vinyl ethers, vinyl ketones, etc., such as vinyl acetate, vinyl butyrate, isopropenyl acetate, vinyl formate, vinyl acrylates, 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-vinyl acetamide, N-vinylpyrrolidone, vinylimidazole, din-vinylsulfoxide, divinylsulfone, sodium vinylsulfonate, methylvinylsulfonate, N-vinylpyrrole, vinylphosphonate, and similar derivatives; Dimethyl fumarate, dimethyl maleate, maleic acid, crotonic acid, fumaric acid, itaconic acid, monomethyl itaconate, t-butylaminoethyl methacrylate, dimethylaminoethyl methacrylate, glycidyl acrylate, allyl alcohol, glycol monoester of itaconic acid, vinylpyridine and similar derivatives. Preferred ethylenically unsaturated monomers are styrene, acrylonitrile, acrylates and acrylamides. In a preferred embodiment, acrylonitrile, styrene, in particular styrene and acrylonitrile in the ratio between 1: 3 to 3: 1 are used as ethylenically unsaturated monomers. Preferably, a macromer is further added to the polymerization. Optionally, the polymerization is further carried out using a moderator and using a radical initiator.

In a preferred embodiment, the solids content of acrylonitrile, styrene and macromer, wherein the proportion of acrylonitrile 10 to 75 wt .-% and preferably 25 to 35 wt .-%, the proportion of styrene 30 to 90 wt .-%, preferably 55 to 70 wt .-% and the proportion of macromer 1 to 10 wt .-%, preferably 3 to 6 wt .-%, 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 10 to 90 wt .-%, particularly preferably 15 to 60 and in particular 20 to

55 wt .-%, based on the total weight of the polymer polyol on. In this case, the solids content, based on the total weight of the polyol component b) is preferably 1 to 10 wt .-%, particularly preferably 2 to 7 wt .-% and in particular 2.5 to 6 wt .-%.

The solids content of polymer polyols is calculated from the percentage ratio of the monomers used and of the macromers to the carrier polyols used and is usually determined gravimetrically on the finished polymer polyol from the percentage ratio of the solids mass to the total mass of the polymer polyol.

The proportion of polymer polyetherol b2) in the total weight of the polyol component b) is preferably 0.5 to 20 wt .-%. The proportion of polymer polyesterol b3) in the total weight of the polyol component b) is preferably 0 to 30 wt .-%, more preferably 1 to 10 wt .-%. If polymer polyetherol b2) and polymer polyesterol b3) are used together, the ratio of polymer polyetherol b2) to polymer polyesterol b3) is preferably 1:20 to 20: 1, more preferably 1: 5 to 5: 1. In this case, a combination of polymer polyetherol b2) and polymer polyesterol b3) is preferably used for the production of polyurethane foam moldings having a height of at least 1.5 cm, more preferably of at least 5 cm. The term "height" of the polyurethane foam molding is understood to mean the greatest distance in the mold for producing the polyurethane foam molding according to the invention in the direction of rise of the foam Further, blowing agents c) are present in the production of polyurethane foam moldings These blowing agents c) can contain water in addition to water additionally generally known chemically and / or physically kende compounds are used. Chemical blowing agents are compounds which form gaseous products by reaction with isocyanate, such as, for example, water or formic acid. Physical blowing agents are understood as compounds which are dissolved or emulsified in the starting materials of polyurethane production and evaporate under the conditions of polyurethane formation. These are, for example, hydrocarbons, halogenated hydrocarbons, and other compounds, such as perfluorinated alkanes, such as perfluorohexane, chlorofluorocarbons, and ethers, esters, ketones, acetals or mixtures thereof, for example (cyclo) aliphatic hydrocarbons having 4 to 8 Carbon atoms, or fluorocarbons, such as Solkane ^® 365 mfc Solvay Fluorides LLC. In a preferred embodiment, the blowing agent employed is a mixture containing at least one of these blowing agents and water, in particular water as the sole blowing agent. If no water is used as blowing agent, preferably only physical blowing agents are used.

The content of water in a preferred embodiment is from 0.1 to 2 wt .-%, preferably 0.2 to 1, 5 wt .-%, particularly preferably 0.3 to 1, 2 wt .-%, based on the total weight of components a) to f). In a further preferred embodiment, microbubbles containing physical blowing agent are added to the reaction of components a) to f) as additional blowing agent. The hollow microspheres can also be used in admixture with the abovementioned propellants. The hollow microspheres usually consist of a shell of thermoplastic polymer and are filled in the core with a liquid, low-boiling substance based on alkanes. The production of such hollow microspheres is described, for example, in US Pat. No. 3,615,972. The hollow microspheres generally have a diameter of 5 to 50 μm. Examples of suitable hollow microspheres are available from Akzo Nobel under the trade name Expancell® ^®.

The hollow microspheres are generally added in an amount of 0.5 to 5 wt .-%, based on the total weight of components b), c) and d). As chain extenders and / or crosslinking agents d) substances having a molecular weight of preferably less than 500 g / mol, particularly preferably from 60 to 400 g / mol are used, chain extenders having 2 isocyanate-reactive hydrogen atoms and crosslinking agent 3 isocyanate-reactive hydrogen atoms. These can preferably be used individually or in the form of mixtures. Preference is given to using diols and / or triols having molecular weights of less than 400, more preferably from 60 to 300 and in particular from 60 to 150. For example, aliphatic, cycloaliphatic and / or araliphatic diols having 2 to 14, preferably 2 to 10 carbon atoms, such as ethylene glycol, 1, 3-propanediol, 1, 10-decanediol, 1, 2, 1, 3, 1, 4-dihydroxycyclohexane, diethylene glycol, dipropylene glycol and 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. Particularly preferred chain extenders (d) are monoethylene glycol, 1,4-butanediol, glycerol or mixtures thereof. If chain extenders, crosslinking agents or mixtures thereof are used, these are expediently used in amounts of from 1 to 60% by weight, preferably from 1.5 to 50% by weight and in particular from 2 to 40% by weight, based on the weight of the components b) and d) are used. As catalysts e) for the preparation of the polyurethane foams, preference is given to using compounds which greatly accelerate the reaction of the polyols b) and optionally chain extenders and crosslinking agents d) with the organic, optionally modified polyisocyanates a). Examples which may be mentioned are amidines, such as 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine, tertiary amines, such as triethylamine, tributylamine, dimethylbenzylamine, N-methyl-, N-ethyl-, N-cyclohexylmorpholine,

Ν, Ν, Ν ', Ν'-tetramethylethylenediamine, Ν, Ν, Ν', Ν'-tetramethyl-butanediamine, Ν, Ν, Ν ', Ν'-tetramethyl-hexanediamine, pentamethyl-diethylenetriamine, tetramethyl-diaminoethyl ether, Bis (dimethylaminopropyl) urea, dimethylpiperazine, 1, 2-dimethylimidazole, 1-azabicyclo- (3,3,0) -octane and preferably 1,4-diazabicyclo- (2,2,2) -octane and alkanolamine compounds such as triethanolamine, triisopropanolamine, N-methyl- and N-ethyldiethanolamine and dimethylethanolamine. Also contemplated are organic metal compounds, preferably organic tin compounds such as stannous salts of organic carboxylic acids, e.g. Tin (II) acetate, stannous octoate, stannous (II) ethylhexanoate, and stannous (II) laurate and the dialkyltin (IV) salts of organic carboxylic acids, e.g. Dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate and dioctyltin diacetate; and bismuth carboxylates such as bismuth (III) neodecanoate, bismuth 2-ethylhexanoate and bismuth octanoate or mixtures thereof. The organic metal compounds can be used alone or preferably in combination with strongly basic amines. When component (b) is an ester, it is preferred to use only amine catalysts.

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

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

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

Examples of suitable further 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 molecular weights of 60 to 400 g / mol, such as in 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 a carboxylic acid and optionally a ca hydrobromic acid, as disclosed, for example, in US Pat. No. 4,764,537. Preferably, reaction mixtures according to the invention contain no further release agents.

Fillers, in particular reinforcing fillers, are the conventional, customary organic and inorganic fillers, reinforcing agents, weighting agents, coating compositions, etc., to be understood. Specific examples are: inorganic fillers, such as silicate minerals, for example phyllosilicates, such as antigorite, bentonite, serpentine, hornblende, amphiboles, chrysotile and talc, metal oxides, such as kaolin, aluminum oxides, titanium oxides, zinc oxide and iron oxides, Metal salts such as chalk and barite, and inorganic pigments such as Cadmiumsul- fid, zinc sulfide and glass, etc. Preferably used are kaolin (China Clay), aluminum silicate and coprecipitates of barium sulfate and aluminum silicate. Suitable organic fillers are, for example, carbon black, melamine, rosin, cyclopentadienyl resins and graft polymers and also cellulose fibers, polyamide, polyacrylonitrile, polyurethane and polyester fibers based on aromatic and / or aliphatic dicarboxylic acid esters and in particular carbon fibers.

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

The present invention further provides a process for producing a polyurethane foam molding, in particular an integral polyurethane foam in which the components a) to c) and optionally d), e) and / or f) are mixed together in amounts such that the equivalence ratio of NCO- Groups of polyisocyanates (a) to the sum of the reactive hydrogen atoms of components (b), (c) and (d) 1: 0.8 to 1: 1, 25, preferably 1: 0.9 to 1: 1, 15.

The polyurethane foam moldings according to the invention are preferably prepared by the one-shot process with the aid of the low-pressure or high-pressure technique in closed, suitably tempered molds. The molds are usually made of metal, e.g. Aluminum or steel. These procedures are described for example by Piechota and Röhr in "integral foam", Carl Hanser Verlag, Munich, Vienna, 1975, or in the "Plastics Handbook", Volume 7, Polyurethane, 3rd edition, 1993, Chapter 7.

The starting components a) to f) are preferably mixed at a temperature of 15 to 90 ° C, more preferably from 25 to 55 ° C and optionally introduced the reaction mixture under elevated pressure in the mold. The mixing can be carried out mechanically by means of a stirrer or a stirring screw or under high pressure in the so-called countercurrent injection method. The mold temperature is expediently from 20 to 160.degree. C., preferably from 30 to 120.degree. C., particularly preferably from 30 to 60.degree. In the context of the invention, the mixture of components a) to f) is referred to as reaction mixture at reaction conversions of less than 90%, based on the isocyanate groups.

The amount of the reaction mixture introduced into the mold is so determined that the shaped bodies obtained, in particular integral foam, have a

Density of preferably 80 g / L to 500 g / L, more preferably from 150 g / L to 450 g / L. exhibit. The degrees of compaction for the production of the poly- Urethane integral foams are in the range of 1, 1 to 8.5, preferably from 1, 7 to 7.0.

The polyurethane foam molded articles according to the invention are preferably used as a shoe sole and particularly preferably as an (intermediate) sole, for example for street shoes, sports shoes, sandals and boots. In particular, the integral polyurethane foams according to the invention are used as a midsole for sports shoes or as sole material for high-heeled women's shoes. The thickness of the sole at the thickest point is preferably more than 3 cm, more preferably more than 5 cm. Furthermore, polyurethane foams according to the invention can be used in the interior of transport vehicles, for example in cars, as steering wheels, headrests or control buttons or as chair armrests. Other uses are as an armrest for chairs or as motorcycle seats. In the following, the invention will be illustrated by means of examples. Examples

Used feedstocks

Polyol 1: polyesterol based on adipic acid, monoethylene glycol, diethylene glycol and glycerol with an OH number of 91 mg KOH / g and a viscosity of

261 mPas at 75 ° C

Polyol 2: Polyesterol based on a mixture of succinic acid, glutaric acid and

Adipic acid, monoethylene glycol and glycerol with an OH number of 58 mg KOH / g and a viscosity of 430 mPas at 100 ° C.

Polyol 3: Polyesterol based on a mixture of succinic acid, glutaric acid, adipic acid and monoethylene glycol having an OH number of 56 mg KOH / g and a viscosity of 650 mPas at 75 ° C.

Polyol 4: graft polyol based on a polyetherol based on glycerol, propylene oxide and ethylene oxide with an ethylene oxide cap, a solids content of 45 wt .-%, an OH number of 20 mg KOH / g and a

Viscosity of 7500 mPas at 25 ° C

Polyol 5: polyetherol based on glycerol, propylene oxide and ethylene oxide with one

Ethylene / propylene oxide Mischcap, an OH number of 56 mg KOH / g and a viscosity of 460 mPas at 25 ° C.

Polyol 6: graft polyol based on polyol 5 with a solids content of 45 wt .-% of an OH number of 30 mg KOH / g and a viscosity of 4500 mPas at 25 ° C.

Polyol 7: Graftpolyol PM 245® from Synthesia based on polyesterol having an OH number of 60 mg KOH / g

KV1: Monethylene glycol

V1: triethanolamine V2: glycerin

Cat 1 Dabco dissolved in monoethylene glycol

Cat 2 Niax A1® from Air Products

Stabi Dabco DC 193® from Air Products

IS0 1: monomer MDI

ISO 2: monomeric MDI containing about 25 weight percent carbodiimide modified monomeric MDI

DI BIS: Diglycol-bis-chloroformate

FP: color paste

Prepolymer Preparation: Prepolymer 1 (Prepol):

In a 2 L 4-necked flask with nitrogen inlet, stirrer, condenser and dropping funnel, 927.9 g of ISO 1, 75 g of ISO 2 and 0.15 g of DI BIS were initially charged and heated to about 60 ° C. At 60 ° C 496.95 g of the polyol 1 were added slowly over a period of 30 minutes and stirred at 80 ° C for 2 hours. The prepolymer obtained had an NCO content of 20.0% prepolymer 2 (Prepo 2):

In a 2 L 4-necked flask with nitrogen inlet, stirrer, condenser and dropping funnel, 884.85 g of ISO 1, 180 g of ISO 2 and 0.15 g of DI BIS were initially charged and heated to about 60 ° C. At 60 ° C 435g of the polyol 2 were added slowly over a period of 30 minutes and stirred at 80 ° C for 2 hours. The prepolymer obtained had an NCO content of 21, 8%

The inventive examples E1 to E4 and the comparative examples V1 to V4 were carried out. For this purpose, the components indicated in Table 1 (in parts by weight) were mixed with the labeled isocyanate prepolymers at specified isocyanate index and foamed once each free and once in a sole mold with the heights specified in the table height in cm (HH), so moldings with a density of 380 g / L emerged. The density of the free-foamed polyurethane foam in g / L (density fr) is also given in Table 1. Table 1:

24 hours after preparation, the moldings were examined. In this case, both the foam-free foam and the molded body according to Comparative Examples V 1 to V4 showed a significant shrinkage or local shrinkage on the surface of the free-foamed foam and the moldings according to the inventive examples E1 to E4 showed no signs of shrinkage. Furthermore, the moldings were characterized by a good surface quality. The shaped body according to Example E3 had a coarse, inhomogeneous cell structure in the upper third of the sole, which could be compressed under load (human body) and thus had a negative effect on the stability of the shoe. The combination of polymer polyetherol and polymer polyesterol according to Example E4, this disadvantage could be eliminated. The polyurethane integral foam according to Example E4 showed a homogeneous microcellular foam structure.

Claims

claims

Process for the preparation of polyurethane foam moldings in which a) organic polyisocyanates with

b) Polyols containing

b1) polyesterols

b2) polymer polyetherols with a proportion of primary OH groups of less than 50%,

c) propellants, and optionally

d) chain extenders and / or crosslinking agents,

e) catalysts and

f) other aids and / or additives,

is mixed into a reaction mixture, placed in a mold and allowed to react to a polyurethane foam molding.

A method according to claim 1, characterized in that component b) as component b3) contains a polymer polyesterol.

A method according to claim 1 or 2, characterized in that the density is 80 to 500 g / L.

Use of a mixture of polymer polyetherols and polymer polyesterols for the production of polyurethane foam moldings.

Polyurethane foam molding obtainable according to one of claims 1 to 3.

6. Use of a polyurethane foam molding according to claim 5 as a shoe sole.