EP3931230A1

EP3931230A1 - Isocyanate-terminated prepolymers for the production of integral polyurethane foams

Info

Publication number: EP3931230A1
Application number: EP19708820.6A
Authority: EP
Inventors: Jakob MARBACH; Rolf Albach; Sascha Froebel; Marc SCHUMACHER; Markus MEURESCH; Hans-Detlef Arntz; Annika HILL; Stephan KRETSCHMANN; Ludger SCHLAG
Original assignee: Covestro Intellectual Property GmbH and Co KG
Current assignee: Covestro Intellectual Property GmbH and Co KG
Priority date: 2019-02-28
Filing date: 2019-02-28
Publication date: 2022-01-05
Also published as: WO2020173568A1; CN113454134A; US20220106431A1

Abstract

The invention relates to a method for producing a prepolymer for the production of an integral polyurethane foam. According to the invention, the prepolymer is or can be obtained by reaction of a composition that contains or consists of the following components: component A containing or consisting of a polyoxymethylene-polyoxyalkylene block copolymer having a hydroxyl number according to DIN 53240-2 (November 2007) DIN 53240-1:2013-06 of 20 mg KOH/g to 200 mg KOH/g as component A1, optionally a polymer that is different from component A1 and that has an average number of at least 1.7 Zerewitinoff-active hydrogen atoms and a hydroxyl number according to DIN 53240-2 (November 2007) of 40 mg KOH/g to 80 mg KOH/g as component A2, optionally a compound that is different from components A1 and A2 and has at least two Zerewitinoff-active hydrogen atoms and a molecular weight of 50 to 500 g/mol as component A3, component B containing or consisting of di- and/or polyisocyanates with an NCO content according to EN ISO 11909 (2007) of 15 to 45 wt.-% relative to component B, 0.04 to 1.0 wt.-%, relative to the composition, a proton acid as component C, and optionally a component D that contains auxiliary agents, at a characteristic number of 450 to 850. The invention further relates to the prepolymer obtained by the method, to an integral polyurethane foam based on the prepolymer, and to the use thereof.

Description

Isocvanate-terminated prepolymers for the production of polyurethane integral foams

The invention relates to a method for producing a prepolymer for producing a polyurethane integral foam, the composition for producing the prepolymer containing an acid, as well as the prepolymer obtained by the method and a polyurethane integral foam based on the prepolymer.

Molded parts made from integral polyurethane foam have a cellular core and a largely cell-free edge zone. Since the skin that forms during the manufacturing process consists of the same material as the cell core, i.e. it is an integral part of the molded part, this type of polyurethane foam is known as integral foam. Polyurethane integral foam has been widely used as a material for shoe soles, among other things. This is mostly flexible integral foam with a bulk density in the range from 0.3 to 0.6 g / cm ³ . Flexible integral foam is also used in the automotive industry.

Polyurethane integral foam is usually produced by mixing an isocyanate component and a polyol component and, if necessary, auxiliaries and additives with one another and then pouring them into a mold, where they react to form a foam. Such processes are known as reaction injection molding or RIM processes. The components used have a high reactivity, so that they have to be metered and mixed into a reaction mixture in a short time. Furthermore, it must be ensured that a mold can be filled quickly with the reaction mixture. In order to achieve good mixing of the components and to ensure quick filling into the molds, the components must have a low viscosity of <1500 mPa * s at 25 ° C. Since the components may be stored for some time before they are further processed, their properties should not change when they are stored. In these processes, the use of isocyanate-terminated prepolymers as the isocyanate component has proven to be advantageous in order to meet the requirements for the production process and the integral polyurethane foam obtained.

Isocyanate-terminated prepolymers are generally obtained by first preparing a polyether or polyester-polyol by reacting the corresponding monomers with a catalyst, which is then reacted with a poly- or diisocyanate. It has been observed that the viscosity of the prepolymers increases during storage and so does the content of free isocyanate groups required for the subsequent reaction to form the polyurethane sinks. This can probably be attributed to the fact that the terminal isocyanate groups of the prepolymers react with one another and trimerization and / or oligomerization of the isocyanates occurs. This adversely affects both the reactivity of the prepolymer and its processability in the production process of the polyurethane. This effect occurs in particular when using polyols which have been produced by means of double metal cyanide catalysts (DMC catalysts).

Various prepolymers for polyurethane synthesis are known from the prior art.

CN 101353413 discloses a prepolymer with terminal isocyanate groups based on MDI for the production of high-resilience polyurethane foam. The prepolymer is obtained by reacting a polyether polyol with isocyanate and an acid as a polymerization inhibitor. The prepolymer is intended to overcome problems that arise from the use of unmodified MDI in the production of high-resilience polyurethane foam. The publication does not deal with the properties of the prepolymer, but refers exclusively to the properties of the high resilience polyurethane foam obtained.

WO 2014/095679 discloses NCO-modified polyoxymethylene block copolymers and their use as prepolymers for producing flexible polyurethane foams and thermoplastic polyurethanes. The publication discloses that the viscosity of the prepolymer can be controlled in a targeted manner via the length of the polyoxymethylene blocks in relation to the additional oligomers. The document does not deal with the storage stability of the prepolymer.

EP 1 589 071 A1 discloses a polyether polyol for the production of isocyanate-terminated prepolymers for elastomers, sealants based on polyurethane. The polyol is produced by ring-opening polymerization of alkylene oxide in the presence of a DMC catalyst and a phosphoric acid and / or a phosphoric acid ester and is then reacted with an isocyanate. The prepolymer obtained is said to have an improved shelf life. In the experimental part, isocyanate-terminated prepolymers are disclosed which have a viscosity at 25 ° C. of 29700 to 31200 mPa * s. However, prepolymers with such a high viscosity cannot be used in production processes for integral polyurethane foams because they cannot be filled into a mold quickly enough.

There is a need for isocyanate-terminated prepolymers for the production of polyurethane integral skin foams which have a low viscosity of <1500 mPa * s at 25 ° C and their properties hardly change during storage over a period of several months at 25 ° C under a protective gas atmosphere.

The object of the present invention is to provide an isocyanate-terminated prepolymer which has a low dynamic viscosity of <1500 mPa * s at 25 ° C. and which has an improved storage life. This applies in particular to changes in the dynamic viscosity and the NCO content of the prepolymer that occur during storage. In particular, an isocyanate-terminated prepolymer with the aforementioned properties is to be made available, in the production of which a polyol component is used which was produced in the presence of a DMC catalyst and which still contains the DMC catalyst in an amount of 10 to 5000 ppm . Furthermore, the prepolymer should be suitable for use in the production of shoe soles.

This object was achieved by a process for the production of a prepolymer for the production of a polyurethane integral skin foam, the prepolymer being obtained or being obtainable by reacting a composition containing or consisting of the following components:

Component A containing or consisting of

- a polyoxymethylene-polyoxyalkylene block copolymer with a hydroxyl number according to DIN 53240-2 (November 2007) of 20 mg KOH / g to 200 mg KOH / g as component Al,

- optionally a polymer different from component Al with an average number of at least 1.7 Zerewitinoff-active hydrogen atoms and a hydroxyl number according to DIN 53240-2 (November 2007) of 40 mg KOH / g to 80 mg KOH / g as component A2,

- optionally one of the components Al and A2 different compound with at least two Zerewitinoff-active hydrogen atoms and a molecular weight of 50 to 500 g / mol as component A3,

Component B containing or consisting of di- and / or polyisocyanates with an NCO content according to EN ISO 11909 (2007) of 15 to 45% by weight based on component B,

0.04 to 1.0% by weight, based on the composition, of a protic acid as component C, and optionally a component D containing auxiliaries,

with a code from 450 to 850.

An improved storage stability is understood to mean that the dynamic viscosity of the prepolymer changes after storage for six months at 25 ° C. under a protective gas atmosphere not increased by more than 55%. These storage conditions can be simulated by storing a sample at 80 ° C for a period of 3 days under a nitrogen atmosphere. In addition, the NCO content of the prepolymer should not decrease by more than 10% during storage under the conditions mentioned above, so that the reactivity of the prepolymer is sufficiently high for the production of a polyurethane integral foam even after storage.

The isocyanate index (also called index or isocyanate index) is the quotient of the amount of substance [mol] of isocyanate groups actually used and the amount of substance [mol] of isocyanate-reactive groups actually used, multiplied by 100: index = (Moles of isocyanate groups / moles of isocyanate-reactive groups) * 100

The NCO value (also: NCO content, isocyanate content) is determined using EN ISO 11909: 2007. Unless otherwise stated, the values are at 25 ° C.

Component Al

Component Al is a polyoxymethylene-polyoxyalkylene block copolymer with a hydroxyl number according to DIN 53240-2 (November 2007) of 20 mg KOH / g to 200 mg KOH / g, preferably from 30 mg KOH / g to 150 mg KOH / g, further preferably from 40 mg KOH / g to 100 mg KOH / g. The composition for producing the prepolymer preferably contains 10.50% by weight to 30.50% by weight of component Al, based on the sum of all components in the composition. Polyoxymethylene-polyoxyalkylene block copolymers for the purposes of the invention refer to polymeric compounds which contain at least one polyoxymethylene block and at least one additional polyoxyalkylene or polyoxyalkylene carbonate block and preferably do not exceed a four-digit molecular weight.

Component Al is preferably produced by the catalytic addition of alkylene oxides and optionally further comonomers onto at least one polymeric formaldehyde starter compound which has at least one terminal hydroxyl group in the presence of a double metal cyanide (DMC) catalyst, wherein

(i) In a first step, the DMC catalyst is activated in the presence of the polymeric formaldehyde starter compound at an activation temperature (Tact) of 20 to 120 ° C, with a partial amount (based on the total amount of the Activation and polymerization, the amount of alkylene oxides used) is added by one or more alkylene oxides ("activation"),

(ii) in a second step, one or more alkylene oxides and, if appropriate, further comonomers are added to the mixture resulting from step (i), the alkylene oxides used in step (ii) being different from the alkylene oxides used in step (i) (“polymerization "), Suitable polymeric formaldehyde starter compounds are in principle those oligomeric and polymeric forms of formaldehyde which have at least one terminal hydroxyl group for reaction with the alkylene oxides and any further comonomers. The term “terminal hydroxyl group” is understood to mean, in particular, a terminal hemiacetal functionality which results as a structural feature via the polymerization of the formaldehyde. For example, the starter compounds can be oligomers and polymers of formaldehyde of the general formula HO (CH ₂ O) nH, where n is an integer> 2 and where polymeric formaldehyde typically has n> 8 repeating units.

Preferred polymeric formaldehyde starter compounds generally have molecular weights from 62 to 30,000 g / mol, preferably from 62 to 12,000 g / mol, particularly preferably from 242 to 6000 g / mol and very particularly preferably from 242 to 3000 g / mol and include from 2 to 1000, preferably from 2 to 400, particularly preferably from 8 to 200 and very particularly preferably from 8 to 100 repeating oxymethylene units. The starter compounds used typically have a functionality (F) of 1 to 3, but in certain cases they can also be more functional, that is to say have a functionality> 3. Open-chain polymeric formaldehyde starter compounds with terminal hydroxyl groups, which have a functionality of 1 to 10, preferably 1 to 5, particularly preferably 2 to 3, are preferably used. Linear polymeric formaldehyde starter compounds which have a functionality of 2 are very particularly preferably used. The functionality F corresponds to the number of OH end groups per molecule.

The preparation of the polymeric formaldehyde starter compounds which are used for the process for the preparation of component Al can be carried out according to known processes (cf., for example, M. Haubs et. Al., 2012, Polyoxymethylenes, Ullmann's Encyclopedia of Industrial Chemistry; G. Reus et. al., 2012, Formaldehyde, ibid). The formaldehyde starter compounds can in principle also be used in the form of a copolymer, 1,4-dioxane or 1,3-dioxolane, for example, being copolymerized as comonomers in addition to formaldehyde. Further suitable formaldehyde copolymers are copolymers of formaldehyde and of trioxane with cyclic and / or linear formals, such as, for example, butanediol formal, or epoxides. It is also conceivable that higher homologous aldehydes, such as, for example, acetaldehyde, propionaldehyde, etc., are incorporated into the formaldehyde polymer as comonomers. It is also conceivable that formaldehyde starter compounds are in turn prepared starting from H-functional starter compounds; in particular, by using polyvalent starter compounds, polymeric formaldehyde starter compounds with a Hydroxy end group functionality F> 2 obtained (cf., for example, WO 1981001712 A1, Bull. Chem. Soc. J "1994, 67, 2560-2566, US 3436375, JP 03263454, JP 2928823).

Mixtures of different polymeric formaldehyde starter compounds or mixtures with other H-functional starter compounds can also be used for the process for producing component Al. Suitable H-functional starter substances (“starters”) which can be used are compounds with H atoms active for the alkoxylation, which have a molar mass of 18 to 4500 g / mol, preferably 62 to 2500 g / mol and particularly preferably 62 to 1000 have g / mol. Groups with active H atoms which are active for the alkoxylation are, for example, -OH, -NH2 (primary amines), -NH- (secondary amines), -SH and -C02H, preferred are -OH and -NH2, and -OH is particularly preferred. As H-functional starter substance, for example, one or more compounds are selected from the group consisting of monohydric or polyhydric alcohols, polyhydric amines, polyhydric thiols, amino alcohols, thioalcohols, hydroxyesters, polyether polyols, polyester polyols, polyester ether polyols, polyether carbonate polyols, polycarbonate polyols, polycarbonates, polyethylene imines, polyether amines , Polytetrahydrofurans (e.g. PolyTHF® from BASF), polytetrahydrofuranamines, polyether thiols, polyacrylate polyols, castor oil, the mono- or diglyceride of ricinoleic acid, monoglycerides of fatty acids, chemically modified mono-, di- and / or triglycerides of fatty acids, and C1- C24 alkyl fatty acid esters containing on average at least 2 OH groups per molecule are used.

It is known that formaldehyde polymerizes even in the presence of small traces of water. In aqueous solution, depending on the concentration and temperature of the solution, a mixture of oligomers and polymers of different chain lengths is formed, which are in equilibrium with molecular formaldehyde and formaldehyde hydrate. So-called paraformaldehyde precipitates out of the solution as a white, poorly soluble solid and is usually a mixture of linear formaldehyde polymers with n = 8 to 100 oxymethylene repeat units.

In one embodiment, polymeric formaldehyde or so-called paraformaldehyde, which is commercially available and inexpensive, is used directly as the starter compound. In particular, polyoxymethylene blocks with a defined molecular weight and functionality can be introduced into the product via the molecular weight and the end group functionality of the polymeric formaldehyde starter compound.

Advantageously, in the process for the production of component Al, the catches of the polyoxymethylene block can be controlled simply via the molecular weight of the formaldehyde starter compound used. Linear formaldehyde Starter compounds of the general formula H0- (CH ₂ 0) nH, where n is an integer> 2, preferably with n = 2 to 1000, particularly preferably with n = 2 to 400 and very particularly preferably with n = 8 to 100, with two terminal hydroxyl groups used. In particular, mixtures of polymeric formaldehyde compounds of the formula HO- (CH 2 O) nH, each with different values for n, can also be used as starter compounds. In a preferred embodiment, the mixtures of polymeric formaldehyde starter compounds of the formula HO- (CH ₂ O) nH used contain at least 1% by weight, preferably at least 5% by weight and particularly preferably at least 10% by weight, of polymeric formaldehyde compounds with n> 20.

In particular, polyoxymethylene block copolymers which have an A-B-A block structure comprising an inner polyoxymethylene block (B) and outer oligomeric blocks (A) can be obtained via the process for producing component Al. It is also possible to use formaldehyde starter compounds with a hydroxyl end group functionality F> 2, which consequently results in homologous block structures B (-A) y with a number y> 2 of outer oligomeric blocks (A), which are correspondingly derived from the functionality of the formaldehyde starter compound used can be shown. It is also possible in principle to use formaldehyde starter compounds with a functionality F <2; this can also be, for example, linear formaldehyde starter compounds with F = 1, which are substituted at one end of the chain with a protective group or by other chemical radicals.

Component Al preferably consists of a polyoxymethylene-polypropylene oxide block copolymer or a polyoxymethylene-polyoxyalkylene carbonate block copolymer, the block copolymer preferably having two terminal polyoxyalkylene blocks.

The outer oligomeric blocks (A) are preferably polyoxyalkylene or polyoxyalkylene carbonate blocks, polyoxyalkylene or polyoxyalkylene carbonate blocks in the context of the invention also being understood as meaning those blocks in which (small) proportions of further comonomers, generally less than 50 mol -%, preferably less than 25 mol%, based on the total amount of all repeat units present in the oligomeric block, are polymerized.

A polyoxyalkylene carbonate block within the meaning of the invention denotes a polymeric structural unit 0 [(C ₂ R ¹ R ² R ³ R ⁴ 0) _x (C0 ₂ ) (C ₂ R ¹ R ² R ³ R ⁴ 0) _y ] _z -, where x> 1, y> 0 and z> 1, where R ¹ , R ² , R ³ and R ⁴ independently of one another are hydrogen, an optionally additional heteroatom such as nitrogen, oxygen, silicon, sulfur or phosphorus-containing alkyl or aryl radical and can differ in different repetition units. The term "alkyl" generally includes, in the context of the entire invention, substituents from the group n-alkyl such as methyl, ethyl or propyl, branched alkyl and / or cycloalkyl. In the context of the entire invention, the term "aryl" generally encompasses substituents from the group consisting of mononuclear carbo or heteroaryl substituents such as phenyl and / or polynuclear carbo or heteroaryl substituents, optionally with further alkyl groups and / or heteroatoms such as nitrogen, oxygen, silicon, sulfur or Phosphorus can be substituted. The radicals R ¹ , R ² , R ³ and R ⁴ can be linked to one another within a repeating unit in such a way that they form cyclic structures, such as, for example, a cycloalkyl radical that is incorporated into the polymer chain via two adjacent carbon atoms.

The DMC catalyst is preferably activated in the presence of the polymeric formaldehyde starter compound. The starter compound and the DMC catalyst can optionally be suspended in a suspension medium. It is also possible to use a further liquid starter compound (“costarter”) in the mixture, the DMC catalyst and the polymeric formaldehyde starter compound being suspended in this.

According to the invention, the DMC catalyst is activated at an activation temperature Tact in the range from 20 to 120.degree. C., preferably from 30 to 120.degree. C., particularly preferably from 40 to 100.degree. C. and very particularly preferably from 60 to 100.degree.

"Activation" of the DMC catalyst is to be understood as a step in which a partial amount of alkylene oxide is added to the DMC catalyst suspension at the specific activation temperature and the addition of the alkylene oxide is then interrupted, with the development of heat due to a subsequent exothermic chemical reaction, which can lead to a temperature spike (“hotspot”) and a pressure drop in the reactor is observed due to the conversion of alkylene oxide.

DMC catalysts suitable for the process for producing component Al for use in the homopolymerization of alkylene oxides are known in principle from the prior art (see, for example, US Pat. No. 3,404,109, US Pat. No. 3,829,505, US Pat. No. 3,941 849 and US-A 5 158 922). DMC catalysts, which are described, for example, in US Pat. No. 5,470,813, EP-A 700 949, EP-A 743 093, EP A 761 708, WO 97/40086, WO 98/16310 and WO 00/47649 have a very high activity in the polymerization of alkylene oxides and possibly the copolymerization of alkylene oxides with suitable comonomers and enable the production of polyoxymethylene copolymers with very low catalyst concentrations, so that separation of the catalyst from the finished product is generally no longer necessary. A typical example are the highly active DMC catalysts described in EP-A 700 949, which in addition to a double metal cyanide compound (for example zinc hexacyanocobaltate (III)) and a organic complex ligands (e.g. tert-butanol) also contain a polyether with a number average molecular weight greater than 500 g / mol. Preference is given to using Al DMC catalysts for the synthesis of components which have been prepared with the addition of a base, preferably KOH. Such a particularly preferred DMC catalyst is one according to Example 6 of WO 01/80994 A1. A DMC catalyst containing zinc hexacyanocobaltate, tert-butanol and polypropylene glycol with a number-average molecular weight of approx. 1000 g / mol is preferably used for the synthesis of component Al.

The concentration of DMC catalyst used is typically 10 to 10000 ppm, particularly preferably 20 to 5000 ppm and most preferably 50 to 2000 ppm, based on the mass of the polyoxymethylene block copolymer to be produced. Depending on the requirements of the downstream application, the DMC catalyst can be left in the product or (partially) separated off. The (partial) separation of the DMC catalyst can take place, for example, by treatment with adsorbents and / or filtration. Processes for the separation of DMC catalysts are described, for example, in US-A 4,987,271, DE-A 3132258, EP-A 0 406 440, US-A 5,391,722, US-A 5,099,075, US-A 4,721,818, US-A 4,877,906 and EP- A 0 385 619. According to the invention, component Al and optionally also further components of component A contain a residual content of DMC catalyst (s), so that component A has a total content of DMC catalyst (s) of 10 to 5,000 ppm, preferably from 10 to 3,000 ppm, based in each case on component A.

In a preferred embodiment of the process according to the invention, at least component Al was prepared in the presence of a double metal cyanide catalyst and component Al still contains this double metal cyanide catalyst at least partially, the content of double metal cyanide catalyst based on component A being 10 to 5000 ppm, preferably 1000 up to 2500 ppm, and the content of double metal cyanide catalyst is determined on the basis of the amount of metal content of the double metal cyanide catalyst determined in accordance with DIN-ISO 17025 (August 2005). The amount of metal content in the DMC catalyst can either be determined for the entire polyol component A or, alternatively, separately for each of the components A1 and A2. The amount of catalyst can then be calculated using the information on the content of metal in the DMC catalyst and the molecular weight of the DMC catalyst. It should be noted that double metal cyanide catalysts can contain different metals in different amounts. If the concentration of the double metal cyanide catalyst for the polyol components A1 or A2 was determined individually, the weight-related concentration of the double metal cyanide catalyst for the polyol component A can be calculated as a whole using the weight-related average. Compounds of the general formula (I) are preferred as epoxide (alkylene oxide) for the production of the polyoxymethylene-polyoxyalkylene block copolymers:

used, where R ¹ , R ² , R ³ and R ^{4 are} independently hydrogen or an optionally additional heteroatoms such as nitrogen, oxygen, silicon, sulfur or phosphorus-containing alkyl or aryl radical and can optionally be linked to one another so that they form cyclic structures, such as a cycloalkylene oxide.

Alkylene oxides which are suitable for the polymerization in the presence of a DMC catalyst are preferably used. If different alkylene oxides are used, they can be metered in either as a mixture or one after the other. With the latter metering method, the polyether chains of the polyoxymethylene-polyoxyalkylene block copolymer obtained in this way can for their part likewise have a block structure.

In general, alkylene oxides (epoxides) with 2-24 carbon atoms can be used. The alkylene oxides with 2-24 carbon atoms are, for example, one or more compounds selected from the group consisting of ethylene oxide, propylene oxide, 1-butene oxide, 2,3-butene oxide, 2-methyl-1,2-propene oxide (isobutene oxide), 1-pentene oxide, 2,3-pentene oxide, 2-methyl-1,2-butene oxide, 3-methyl-1,2-butene oxide, 1-hexene oxide, 2,3-hexene oxide, 3,4-hexene oxide, 2-methyl 1,2-pentene oxide, 4-methyl-1,2-pentene oxide, 2-ethyl-1,2-butene oxide, 1-heptene oxide, 1-octene oxide, 1-nonene oxide, 1-decene oxide, 1-undecene oxide, 1-dodecene oxide, 4-methyl-1,2-pentene oxide, butadiene monoxide, isoprene monoxide, cyclopentene oxide, cyclohexene oxide, cycloheptene oxide, cyclooctene oxide, styrene oxide, methyl styrene oxide, pinene oxide, mono- or multiply epoxidized fats as mono-, di- and triglycerides, epoxidized fatty acids, Cl-C24- Esters of epoxidized fatty acids, epichlorohydrin, glycidol, and derivatives of glycidol such as, for example, methyl glycidyl ether, ethyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, glycidyl methacrylate and epoxy-functional alkyoxysilanes such as, for example, 3-glycidyloxy-propyHtrimethoxysilane, 3-glycidyioxypropyltriethoxysilane, 3-glycidyloxypropyltripropoxysilane, 3-glycidyloxypropylmethyl-dimethoxysilane, 3-glycidylysilane, 3-glycidyloxypropyl-glycoxysilane, 3-glycidylysilane, 3-glycidylysilane, 3-glycidyloxypropyl-glycidoxy-propyl-dimethoxysilane, 3-glycidylysilane, 3-glycidyloxy-propylsiloxysilane, 3-glycidylysilane, 3-glycidyloxypropyltrimethoxy The epoxide of the general formula (I) is preferably a terminal epoxide, where R ¹ , R ² and R ^{3 are} hydrogen and R ^{4 is} hydrogen, an alkyl or optionally additional heteroatoms such as nitrogen, oxygen, silicon, sulfur or phosphorus Can be aryl radical and can differ in different repeating units. The alkylene oxides used are preferably ethylene oxide and / or propylene oxide, in particular propylene oxide. The process according to the invention is preferably carried out in such a way that the activation of the catalyst and the conditioning of the polymeric formaldehyde

Starter compound in step (β) is followed by a polymerization step (g) with metering in of one or more alkylene oxides.

In a further embodiment of the process according to the invention, the alkylene oxides are polymerized in the presence of a further comonomer. As further comonomers, for example, all oxygen-containing cyclic compounds, in particular cyclic ethers, such as e.g. Oxetane, THF, dioxane or cyclic acetals such as e.g. 1,3-dioxolane or 1,3-dioxepane, cyclic esters such as e.g. g-butyrolactone, g-valerolactone, -caprolactone, or cyclic

Acid anhydrides such as Maleic anhydride, glutaric anhydride or phthalic anhydride and carbon dioxide are used. Carbon dioxide is preferably used as comonomer.

Further co-monomers can be metered in as a pure substance, in solution or as a mixture with one or more alkylene oxides. The metering in of further comonomers can also take place in parallel with the metering in or following the metering in of the alkylene oxides. In a preferred embodiment of the process according to the invention, in addition to the addition of the alkylene oxide (s) onto the polymeric formaldehyde starter compound, the addition of carbon dioxide (CO 2) as a further comonomer also takes place. This can be used to produce polyoxymethylene-polyoxyalkylene carbonate copolymers. Compared to existing products (e.g. polyether polyols in the polyurethane sector or polyoxymethylene (co) polymers in the POM sector), these also contain CO2 as a cost-effective and environmentally friendly comonomer. Since CO2 etc. is a waste product of the generation of energy from fossil raw materials and is fed to a new chemical recycling, the incorporation of CO2 into the polymer structures results in economic as well as ecological advantages (favorable CCE balance of the product polymers, etc.).

Polyoxymethylene-polyoxyalkylene carbonate block copolymers in the context of the invention denote polymeric compounds which contain at least one polyoxymethylene block and at least one polyoxyalkylene carbonate block. Polyoxymethylene-polyoxyalkylene carbonate block copolymers are of particular interest as starting materials in the polyurethane sector and for applications in the polyoxymethylene (POM) sector. By changing the CCE content, the physical properties can be adapted to the respective application, which opens up new areas of application for these block copolymers. In particular let polyoxymethylene-polyoxyalkylene carbonate copolymers are made available via the process according to the invention, a high content of built-in CO2 being achieved, the products having a comparatively low polydispersity and very few by-products and decomposition products of the polymeric formaldehyde.

Component A2

Component A2 optionally contained in the composition is a polymer different from component Al with an average number of at least 1.7 Zerewitinoff-active hydrogen atoms and a hydroxyl number according to DIN 53240-2 (November 2007) of 40 mg KOH / g to 80 mg KOH / g, preferably from 45 mg KOH / g to 65 mg KOH / g, more preferably from 50 mg KOH / g to 60 mg KOH / g. The composition for producing the prepolymer preferably contains 0.50% by weight to 3.50% by weight of component A2, based on the sum of all components in the composition.

Component A2 preferably has an average number of Zerewitinoff-active hydrogen atoms of at most 4, more preferably component A2 has an average number of 1.9 to 2.5 Zerewitinoff-active hydrogen atoms. Hydrogen bound to N, O or S is called Zerewitinoff active hydrogen (or “active hydrogen”). Such can be determined in a manner known per se by reactivity with a corresponding Grignard reagent. The amount of Zerewitinoff-active H atoms is typically measured via the methane release that is released when the substance to be tested reacts with methyl magnesium bromide (CH3-MgBr) according to the following reaction equation (formula 1):

CH ₃ -MgBr + ROH -> CH ₄ + Mg (OR) Br (1)

Zerewitinoff-active H atoms typically come from C-H acidic organic groups, -OH, -SH, -NH2 or -NHR with R as the organic residue and -COOH.

Component A2 preferably contains or consists of a polyether polyol, polyester polyol, polyether ester polyol, polycarbonate polyol or polyacrylate polyol or mixtures thereof. In a preferred embodiment, component A2 contains or consists of a branched polypropylene oxide.

The polymer contained in component A2 preferably has a number-average molecular weight Mn of> 62 g / mol to <8000 g / mol, preferably from> 90 g / mol to <5000 g / mol and particularly preferably from> 92 g / mol to <2000 g / mol on. The number average molecular weight can in the present invention according to DIN 55672-1 (August 2007) by means of gel permeation chromatography with tetrahydrofuran as the eluent using polystyrene standards. With an average number of at least 2 Zerewitinoff-active hydrogen atoms, component A2 preferably has a number-average molecular weight Mn of 3740-750 g / mol, preferably 2800-1120 g / mol.

Preferred components A2 are polyethers based on polypropylene oxide and a starter molecule. Suitable starter molecules for the polyether polyols are, for example, water, ethylene glycol, diethylene glycol, butyl diglycol, glycerol, diethylene glycol, trimethylolpropane, propylene glycol, pentaerythritol, sorbitol, sucrose, ethylene diamine, toluene diamine, triethanolamine, 1,4-butanediol and 1,6-hexanediol, Hydroxyl-containing esters of such polyols with dicarboxylic acids.

Suitable polyester polyols are, inter alia, polycondensates of di- and also tri- and tetraoienes and di- and also tri- and tetracarboxylic acids or hydroxycarboxylic acids or lactones. Instead of the free polycarboxylic acids, it is also possible to use the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols to prepare the polyesters. Examples of suitable diols are ethylene glycol, butylene glycol, diethylene glycol, triethylene glycol, polyalkylene glycols such as polyethylene glycol, also 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol and isomers, Neopentyl glycol or neopentyl glycol hydroxypivalate. In addition, polyols such as trimethylolpropane, glycerol, erythritol, pentaerythritol, trimethylolbenzene or trishydroxyethyl isocyanurate can also be used.

Polycarboxylic acids that can be used are, for example, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexanedicarboxylic acid, adipic acid, azelaic acid, sebacic acid, glutaric acid, tetrachlorophthalic acid, maleic acid, fumaric acid, 2-succinic acid, 2-succinic acid, diethylalic acid, malonic acid. 2-Dimethylsuccinic acid, dodecanedioic acid, endomethylene-tetrahydrophthalic acid, dimer fatty acid, trimer fatty acid, citric acid, or trimellitic acid can be used. The corresponding anhydrides can also be used as the acid source. If the average functionality of the polyol to be esterified is> 2, monocarboxylic acids such as benzoic acid and hexanecarboxylic acid can also be used. Hydroxycarboxylic acids that can also be used as reactants in the production of a polyester polyol with terminal hydroxyl groups are, for example, hydroxycaproic acid, hydroxybutyric acid, hydroxydecanoic acid,

Hydroxystearic acid and the like. Suitable lactones include caprolactone, butyrolactone and homologues. Polycarbonate polyols which can be used are polycarbonates containing hydroxyl groups, for example polycarbonate diols. These can be obtained by reacting carbonic acid derivatives, such as diphenyl carbonate, dimethyl carbonate or phosgene, with polyols, preferably diols. Examples of such diols are ethylene glycol, 1,2- and 1,3-propanediol, 1,3- and 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol, 1,4-bishydroxymethylcyclohexane, 2 -Methyl-1,3-propanediol, 2,2,4-trimethylpentanediol-1,3, dipropylene glycol, polypropylene glycols, dibutylene glycol, polybutylene glycols, bisphenol A and lactone-modified diols of the type mentioned above.

Polyetherester polyols that can be used are those compounds containing ether groups, ester groups and OH groups. Organic dicarboxylic acids with up to 12 carbon atoms are suitable for the production of the polyetherester polyols, preferably aliphatic dicarboxylic acids with> 4 to <6 carbon atoms or aromatic dicarboxylic acids, which are used individually or in a mixture. Examples are suberic acid, azelaic acid, decanedicarboxylic acid, maleic acid, malonic acid, phthalic acid, pimelic acid and sebacic acid, and in particular glutaric acid, fumaric acid, succinic acid, adipic acid, phthalic acid, terephthalic acid and isoterephthalic acid. As derivatives of these acids, for example, their anhydrides and their esters and half-esters with low molecular weight, monofunctional alcohols with> 1 to <4 carbon atoms can be used. Polyether polyols obtained by alkoxylating starter molecules such as, for example, polyhydric alcohols, are used as a further component for the production of the polyether ester polyols. The starter molecules are at least bifunctional, but can optionally also contain proportions of higher-functional, in particular trifunctional, starter molecules.

Starter molecules for these polyether polyols are, for example, diols with number average molecular weights Mn of preferably> 18 g / mol to <400 g / mol or from> 62 g / mol to <200 g / mol such as 1,2-ethanediol, 1,3-propanediol , 1,2-propanediol, 1,4-butanediol, 1,5-pentenediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,10-decanediol , 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-butene -l, 4-diol and 2-butyne-1,4-diol, ether diols such as diethylene glycol, triethylene glycol, tetraethylene glycol, dibutylene glycol, tributylene glycol, tetrabutylene glycol, dihexylene glycol, trihexylene glycol, tetrahexylene glycol and diethylene glycols such as diethylene glycols of alkyls.

In addition to the diols, polyols with number average functionalities from> 2 to <8, or from> 3 to <4 can also be used, for example 1,1,1-trimethylolpropane, triethanolamine, Glycerol, sorbitan and pentaerythritol as well as polyethylene oxide polyols started on triols or tetraoene with average molecular weights of preferably> 62 g / mol to <400 g / mol or from> 92 g / mol to <200 g / mol.

Polyetherester polyols can also be prepared by the alkoxylation of reaction products obtained by reacting organic dicarboxylic acids and diols. As derivatives of these acids, for example, their anhydrides can be used, such as phthalic anhydride.

Polyacrylate polyols can be obtained by free radical polymerization of olefinically unsaturated monomers containing hydroxyl groups or by free radical copolymerization of olefinically unsaturated monomers containing hydroxyl groups with optionally other olefinically unsaturated monomers. Examples of these are ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, isobornyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, styrene, acrylic acid, acrylonitrile and / or methacrylonitrile. Suitable olefinically unsaturated monomers containing hydroxyl groups are, in particular, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, the hydroxypropyl acrylate isomer mixture obtained by addition of propylene oxide onto acrylic acid, and the hydroxypropyl methacrylate isomer mixture obtained by addition of propylene oxide onto methacrylic acid. Terminal hydroxyl groups can also be present in protected form. Suitable free radical initiators are those from the group of the azo compounds, such as, for example, azoisobutyronitrile (AIBN), or from the group of the peroxides, such as, for example, di-tert-butyl peroxide.

Component A2 can be produced by means of DMC catalysis or by other known production methods. In the case of the use of a DMC catalyst, essentially the same information applies here as described above for component A1.

Component A3

Component A3 optionally contained in the composition is a compound different from components A1 and A2 with at least two Zerewitinoff-active hydrogen atoms and a molecular weight of 50 to 500 g / mol. Component A3 is preferably an oligoalkylene oxide with an OH number between 460 and 700 mg KOH / g and a functionality of 1.8 to 2.4. Component A3 preferably contains or consists of diethanolamine, ethylenediamine, glycerine, triproylene glycol, trimethylolpropane or mixtures thereof, with component A3 preferably containing or consisting of tripylene glycol. The composition for producing the prepolymer preferably contains 1.00% by weight to 8.00% by weight of component A3, based on the sum of all components in the composition.

Component B (isocyanate)

Component B contains or consists of di- and / or polyisocyanates with an NCO content according to EN ISO 11909 (2007) of 15 to 45% by weight, preferably 25 to 35% by weight, based on component B.

The isocyanate component B can in particular comprise an aliphatic or aromatic di- or polyisocyanate. Examples are 1,4-butylene diisocyanate, 1,5-pentane diisocyanate, 1,6-hexamethylene diisocyanate (HDI) or their dimers, trimers, pentamers, heptamers or nonamers or mixtures thereof, isophorone diisocyanate (IPDI), 2,2,4- and / or 2,4,4-trimethylhexamethylene diisocyanate, the isomeric bis (4,4'-isocyanatocyclohexyl) methanes or mixtures thereof with any isomer content, 1,4-cyclohexylene diisocyanate, 1,4-phenylene diisocyanate, 2,4- and / or 2,6 -Tolylene diisocyanate (TDI), 1,5-naphthylene diisocyanate, 2,2'- and / or 2,4'- and / or 4,4'-diphenylmethane diisocyanate (MDI) and / or higher homologues (polymeric MDI), 1,3 - and / or 1,4-bis (2-isocyanato-prop-2-yl) -benzene (TMXDI), 1,3-bis- (isocyanatomethyl) benzene (XDI), as well as alkyl-2,6-diisocyanatohexanoate ( Lysine diisocyanate) with Ci to C _ö -alkyl groups. MDI is preferred.

In addition to the above-mentioned polyisocyanates, modified diisocyanates with uretdione, isocyanurate, urethane, carbodiimide, uretonimine, allophanate, biuret, amide, iminooxadiazinedione and / or oxadiazinetrione structure and unmodified polyisocyanate with more than 2 NCO- Groups per molecule such as, for example, 4-isocyanatomethyl-1,8-octane diisocyanate (nonane triisocyanate) or triphenylmethane-4,4 ', 4 "triisocyanate can also be used. Component B preferably contains carbodiimide-modified diisocyanates with an NCO content according to EN ISO 11909 (2007) from 20 to 50% by weight, more preferably 25 to 35% by weight, based on the carbodiimide-modified diisocytes.

The composition for producing the prepolymer preferably contains 67.85% by weight to 77.65% by weight of component B, based on the sum of all components in the composition.

Component C (acid) Component C is preferably an inorganic acid, a carboxylic acid, a halogenated carboxylic acid, a dicarboxylic acid, a hydroxycarboxylic acid, a sulfonic acid, a phosphoric acid, a phosphoric acid derivative, a paratoluenesulfonic acid, a sulfonic acid or an ammonium salt. Component C is more preferably an aromatic carboxylic acid or an unsaturated or saturated carboxylic acid, an unsaturated or a saturated dicarboxylic acid or an aromatic dicarboxylic acid.

Component C is preferably selected from the group consisting of benzoyl chloride, o-chlorobenzoic acid, ammonium nitrate, ammonium chloride, boron trichloride, boron trifluoride, bromoacetic acid, chloroacetic acid, trichloroacetic acid, 2-chloropropionic acid, citric acid, malonic acid diethyl ester, diphenylacetic acid, nitrous acid, formic acid, Fumaric acid, maleic acid, citraconic acid, adipic acid, glutaric acid, succinic acid, malonic acid, phthalic acid, isophthaloyl chloride, terephthaloyl chloride, malic acid, tartaric acid, uric acid (2,6,8-trihydroxypurine), picric acid (2,4,6-trinitrophenol), phosphoric acid Diphosphoric acid, dibutyl phosphate, sulfuric acid, hydrochloric acid, methanesulfonic acid and p-toluenesulfonic acid chloride. Preferred component C is dibutyl phosphate, hydrochloric acid or 2-chloropropionic acid.

The composition preferably contains 0.04 to 0.5% by weight, more preferably 0.04 to 0.3% by weight, based in each case on the composition, of component C.

In a particularly preferred embodiment, the composition for producing the prepolymer contains 0.05 to 0.2% by weight of component C, based on the sum of all components in the composition.

The amount of component C used is preferably chosen such that the molar amount of substance of the metals of the double metal cyanide catalyst n _Met (DMC) determined according to DIN - ISO 17025 (August 2005) for the molar amount of substance of component C n (C) follows the relationship: n _Met (DMC) · f = n (C), where f is a number from 1.0 to 20.0, preferably from 1.2 to 10.0, more preferably from 3.0 to 6.0, particularly preferably from 3 , 5 to 5.0.

Component D

Component D optionally contained in the composition contains auxiliaries, the auxiliaries preferably being compounds with an antioxidative effect, so-called antioxidants. Suitable antioxidants are preferably sterically hindered phenols, which can preferably be selected from the group consisting of 2,6-di-tert-butyl-4-methylphenol (Ionol), pentaerythritol tetrakis (3- (3,5-di tert-butyl-4-hydroxyphenyl) propionate), octadecyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, triethylene glycol bis (3-tert-butyl-4 -hydroxy-5-methylphenyl) propionate, 2,2'-thio-bis (4-methyl-6-tert-butylphenol) and 2,2'-thio-diethyl-bis [3- (3,5-di-tert -butyl-4-hydroxyphenyl) propionate]. If necessary, these can be used individually or in any combination with one another. The composition for producing the prepolymer preferably contains 0.10 to 0.20% by weight of component D, based on the sum of all components in the composition.

In a further preferred embodiment of the process according to the invention, the prepolymer is obtained or is obtainable by reacting a composition containing or consisting of

10.50% by weight to 30.50% by weight of component Al,

0.50% by weight to 3.50% by weight of component A2,

1.00% by weight to 8.00% by weight of component A3,

67.85% to 77.65% by weight of component B,

0.05 to 0.2% by weight of component C,

0.10 to 0.20% by weight of component D,

the% by weight being based on the sum of all components of the composition, with an index from 600 to 650, preferably with an index from 610 to 630.

The invention further relates to a prepolymer obtained by or obtainable by the process according to the invention. The prepolymer preferably has an NCO content according to EN ISO 11909 (2007) of 15 to 30% by weight, preferably 18 to 21% by weight, based on the mass of the prepolymer. After storage at 80 ° C. for three days, the prepolymer preferably has an NCO content according to EN ISO 11909 (2007) which is not more than 10%, more preferably not more than 3%, lower than the NCO content of the prepolymer at the beginning of storage.

In one embodiment, the prepolymer has a dynamic viscosity at 50 ° C. according to DIN 53019 (2008) of <0.30 Pa * s, preferably <0.15 Pa * s. After storage at 80 ° C. for three days, the prepolymer preferably has a dynamic viscosity at 50 ° C. according to DIN 53019 (2008) which is not more than 50%, more preferably not more than 40% higher than the dynamic viscosity of the prepolymer at the beginning of storage. The dynamic viscosity according to DIN 53019 (2008) is measured with a rheometer with a cone-plate configuration with a distance of 1 mm, at 25 ° C, a shear of 0.01 to 1000 1 / s, the dynamic Viscosity is the mean value of all measuring points measured for a period of 10 minutes at an interval of 10 seconds.

The invention also relates to a polyurethane integral skin foam, obtained by or obtainable by reacting a composition containing or consisting of

- a prepolymer obtained by or obtainable by the process according to the invention,

- a polyol component with a hydroxyl number according to DIN 53240-2 (November 2007) of 140 mg KOH / g to 200 mg KOH / g,

- optional auxiliaries and additives,

with a code from 85 to 110.

The integral polyurethane foam preferably has a molded part density of 450 to 700 g / l, more preferably 550 to 650 g / l, the molded part density being calculated from the volume and the mass of a test body from the integral polyurethane foam.

The polyurethane integral skin foam preferably has a Shore A hardness according to DIN ISO 7619-1 (2012) of 50 to 65, more preferably 55 to 62.

The polyurethane integral skin foam preferably has a tensile strength according to DIN EN ISO 1798 (2008) of 2.5 to 9 MPa, more preferably 3 to 5 MPa.

The integral polyurethane foam preferably has a tensile elongation according to DIN EN ISO 1798 (2008) of 200 to 400%, more preferably 250 to 380%.

The polyurethane integral skin foam preferably has a tear strength according to DIN EN ISO 8067 (2009) of 15 to 20 kN / m, more preferably 15 to 18 kN / m.

The integral polyurethane foam preferably has a rebound resilience according to DIN 53512 (2000) of 15 to 25%, more preferably of 20 to 25%.

The invention further relates to the use of the prepolymer according to the invention or the integral polyurethane foam according to the invention for the production of shoe soles, in particular for the production of shoe soles for sports shoes or hiking shoes.

In a first embodiment, the invention relates to a process for the production of a prepolymer for the production of a polyurethane integral skin foam, the prepolymer is obtained or is obtainable by reacting a composition containing or consisting of the following components:

Component A containing or consisting of

- a polyoxymethylene-polyoxyalkylene block copolymer with a hydroxyl number according to DIN 53240-2 (November 2007) DIN 53240-1: 2013-06 of 20 mg KOH / g to 200 mg KOH / g as component Al,

with a code from 450 to 850.

In a second embodiment, the invention relates to a method according to embodiment 1, where component Al consists of a polyoxymethylene-polypropylene oxide block copolymer or a polyoxymethylene-polyoxyalkylene carbonate block copolymer, the block copolymer preferably having two terminal polyoxyalkylene blocks.

In a third embodiment, the invention relates to a process according to one of embodiments 1 or 2, wherein at least component Al was produced in the presence of a double metal cyanide catalyst and component Al still contains this double metal cyanide catalyst at least partially, the content of double metal cyanide catalyst being based on component A is 10 to 5000 ppm, preferably 1000 to 2500 ppm, and the content of double metal cyanide catalyst is determined on the basis of the amount of metal from the double metal cyanide catalyst determined according to DIN-ISO 17025 (August 2005).

In a fourth embodiment, the invention relates to a method according to embodiment 3, the amount of component C used being selected such that the molar amount of substance of the metals in the double metal cyanide catalyst n _Met (DMC) is determined according to DIN - ISO 17025 (August 2005) for molar amount Amount of substance of component C n (C) the relationship follows: n _Met (DMC) · f = n (C), where f is a number from 1.0 to 20.0, preferably from 1.2 to 10.0, more preferably from 3.0 to 6.0, particularly preferably from 3.5 to 5.0.

In a fifth embodiment, the invention relates to a method according to one of the preceding embodiments, wherein component Al has a hydroxyl number according to DIN 53240-2 (November 2007) of 30 mg KOH / g to 150 mg KOH / g, preferably from 40 mg KOH / g to 100 mg KOH / g.

In a sixth embodiment, the invention relates to a method according to one of the preceding embodiments, where component A2 contains or consists of a polyether polyol, polyester polyol, polyetherester polyol, polycarbonate polyol or polyacrylate polyol or mixtures thereof, with component A2 preferably containing or consisting of a branched polypropylene oxide.

In a seventh embodiment, the invention relates to a method according to one of the preceding embodiments, where component A3 contains or consists of diethanolamine, ethylenediamine, glycerol, triproylene glycol, trimethylolpropane or mixtures thereof, where component A3 preferably contains or consists of tripylene glycol.

In an eighth embodiment, the invention relates to a method according to one of the preceding embodiments, component B being carbodiimide-modified diisocyanates with an NCO content according to EN ISO 11909 (2007) of 20 to 50% by weight based on the carbodiimide-modified diisocyanates, contains.

In a ninth embodiment, the invention relates to a method according to one of the preceding embodiments, where component C is an inorganic acid, a carboxylic acid, a halogenated carboxylic acid, a dicarboxylic acid, a hydroxycarboxylic acid, a sulfonic acid, a phosphoric acid or a phosphoric acid derivative, with component C preferably being dibutyl phosphate , Hydrochloric acid or 2-chloropropionic acid.

In a tenth embodiment, the invention relates to a method according to one of the preceding embodiments, where component C is 0.04 to 0.5% by weight, preferably 0.04 to 0.3% by weight, based in each case on the composition, in the composition are included. In an eleventh embodiment, the invention relates to a method according to one of the above embodiments, wherein the prepolymer is obtained or is obtainable by reacting a composition containing or consisting of

10.50% by weight to 30.50% by weight of component Al,

0.50% by weight to 3.50% by weight of component A2,

1.00% by weight to 8.00% by weight of component A3,

67.85% to 77.65% by weight of component B,

0.05 to 0.2% by weight of component C,

0.10 to 0.20% by weight of component D,

In a twelfth embodiment, the invention relates to a prepolymer obtained by or obtainable by a process according to one of embodiments 1 to 11.

In a thirteenth embodiment, the invention relates to a prepolymer according to

Embodiment 12, wherein the prepolymer has an NCO content according to EN ISO 11909 (2007) of 15 to 30% by weight, preferably 18 to 21% by weight, based on the mass of the prepolymer.

In a fourteenth embodiment, the invention relates to a prepolymer according to

Embodiment 12 or 13, wherein the prepolymer, after storage at 80 ° C. for three days, has an NCO content according to EN ISO 11909 (2007) which is not more than 10%, preferably not more than 3%, lower than the NCO -Content of the prepolymer at the beginning of storage.

In a fifteenth embodiment, the invention relates to a prepolymer according to one of embodiments 12 to 14, the prepolymer having a dynamic viscosity at 50 ° C. according to DIN 53019 (2008) <0.30 Pa * s, preferably <0.15 Pa * s, has, measured with a rheometer with a cone-plate configuration with a distance of 1 mm, at 25 ° C, a shear of 0.01 to 1000 1 / s, wherein the dynamic viscosity is the mean value of all measurement points that for a Period of 10 minutes were measured at intervals of 10 seconds.

In a sixteenth embodiment, the invention relates to a prepolymer according to one of embodiments 12 to 15, wherein the prepolymer, after storage at 80 ° C. for three days, has a dynamic viscosity at 50 ° C. according to DIN 53019 (2008) that is not more than 50 %, preferably not more than 40% higher than the dynamic viscosity of the prepolymer at the beginning of storage, the dynamic viscosity being measured in each case using a rheometer a cone-plate configuration with a distance of 1 mm, at 25 ° C, a shear of 0.01 to 1000 1 / s, where the dynamic viscosity is the mean value of all measuring points, which for a period of 10 minutes at an interval of 10 seconds were measured.

In a seventeenth embodiment, the invention relates to a polyurethane integral skin foam obtained by or obtainable by reacting a composition containing or consisting of

- a prepolymer according to one of the embodiments 12 to 16,

- optional auxiliaries and additives,

with a code from 85 to 110.

In an eighteenth embodiment, the invention relates to a polyurethane

Integral foam according to embodiment 17, wherein the polyurethane integral foam has a molded part density of 450 to 700 g / l, preferably from 550 to 650 g / l, the molded part density being calculated from the polyurethane integral foam using the volume and mass of a test body.

In a nineteenth embodiment, the invention relates to a polyurethane

Integral foam according to embodiment 17 or 18, characterized in that the polyurethane integral foam has a Shore A hardness according to DIN ISO 7619-1 (2012) of 50 to 65, preferably 55 to 62.

In a twentieth embodiment, the invention relates to a polyurethane

Integral foam according to one of the embodiments 17 to 19, wherein the polyurethane integral foam has a tensile strength according to DIN EN ISO 1798 (2008) of 2.5 to 9 MPa, preferably from 3 to 5 MPa.

In a twenty-first embodiment, the invention relates to a polyurethane integral skin foam according to one of embodiments 17 to 20, the polyurethane integral skin foam having a tensile elongation according to DIN EN ISO 1798 (2008) of 200 to 400%, preferably 250 to 380%.

In a twenty-second embodiment, the invention relates to a polyurethane integral skin foam according to one of embodiments 17 to 21, wherein the polyurethane Integral foam has a tear strength according to DIN EN ISO 8067 (2009) of 15 to 20 kN / m, preferably 15 to 18 kN / m.

In a twenty-third embodiment, the invention relates to a polyurethane integral skin foam according to one of embodiments 17 to 22, the polyurethane integral skin foam having a rebound resilience according to DIN 53512 (2000) of 15 to 25%, preferably of 20 to 25%.

In a twenty-fourth embodiment, the invention relates to the use of a prepolymer according to one of embodiments 12 to 16 or a polyurethane integral skin foam according to one of embodiments 17 to 23 for the production of shoe soles, in particular for the production of shoe soles for sports shoes or hiking shoes.

Examples

The present invention is further illustrated by the following examples, but without being restricted thereto.

Synthesis of prepolymers

Various prepolymers were presented and their dynamic viscosity and their NCO content were investigated before and after storage for 3 days at 80 ° C. under a nitrogen atmosphere.

Methods

Amount of catalyst: The levels of Co and Zn in the polyoxymethylene-polypropylene oxide block copolymer (polyol 2) were determined in accordance with DIN - ISO 17025 (August 2005). The amount of catalyst in polyol 2 was calculated from this on the basis of the molecular weight of the DMC catalyst. Since only the polyol contained 2 DMC catalyst residues, the determined corresponds

Amount of substance thus the total amount of DMC catalyst in component A.

OH number: The OH number (hydroxyl number) was determined in accordance with DIN 53240-2 (November 2007).

NCO content: The NCO content was determined in accordance with EN ISO 11909 (2007). Dynamic viscosity: The dynamic viscosity was determined according to DIN 53019 (2008), using a Physica MCR 501 rheometer from Anton Paar. A cone-plate configuration with a distance of 1 mm was selected (DCP25 measuring system). The prepolymer (0.1 g) was applied to the rheometer plate and subjected to a shear of 0.01 to 1000 at 25 ° C 1 / s and the viscosity was measured every 10 s for 10 min. The viscosity given is averaged over all measuring points.

Penetration depth:

To determine the penetration depth, a testing machine is used in which a test stamp is pressed into a cup with the polyurethane foam to be tested with the aid of a defined weight for a defined period of time. In the present invention, the test stamp was in the form of a rod with a diameter of 8 mm. The reaction mixture was mixed for 10 seconds with a Pendraulik upright stirrer at 1400 rpm and placed in a paper cup with a volume of 245 ml. 75 seconds after the start of mixing, the test stamp of the machine with a weight of 505 g was pressed into the fresh foam for 90 seconds and the depth of penetration was then recorded. The smaller the penetration depth, the more the foam has already reacted. In order to determine the optimum, the test is carried out at various indices, the smallest penetration depth being assumed as the optimum.

Molded part and free foam density: The molded part and free foam density were calculated from the volume and the mass of the test specimen.

Shore A hardness: The Shore A hardness was determined in accordance with DIN ISO 7619-1 (2012)

Tensile strength and elongation: The tensile strength and elongation were determined in accordance with DIN EN ISO 1798 (2008).

Tear strength: The tear strength was determined in accordance with DIN EN ISO 8067 (2009). Rebound resilience: The rebound was determined in accordance with DIN 53512 (2000).

materials

Isocyanate 1: 4,4'-methylenediphenyl diisocyanate, NCO content 33.6% by weight; Desmodur® 44M

(Covestro AG Germany)

Isocyanate 2: carbodiimide-modified 4,4'-methylenediphenyl diisocyanate, NCO content 29.5

Wt%; Desmodur® CD-S (Covestro AG Germany)

Isocyanate 3: 5% by weight of HCl in a mixture of 2,4'-methylenediphenyl diisocyanate and 4,4'-methylenediphenyl diisocyanate (11: 9 parts by weight) obtained by gassing MDI with hydrogen chloride Polyol 1: 1,2-propylene glycol-started polypropylene oxide with an OH number of 56 mg

KOH / g, produced under KOH catalysis (contains 0.54 wt.% H2SO4)

Polyol 2: polyoxymethylene-polypropylene oxide block copolymer with an OH number of 57 mg KOH / g produced with double metal cyanide catalysis, the double metal cyanide catalyst being produced according to Example 6 of WO 01/80994 A1

Polyol 3: Glycerol-started polypropylene oxide with an OH number of 56 mg KOH / g, produced under KOH catalysis

Polyol 4: tripropylene glycol from Sigma Aldrich

2-chloropropionic acid (CPA) from Sigma Aldrich

Dibutyl phosphate (DBP)

Antioxidant: Irganox 1135 commercial product from BASF, benzene propionic acid-3,5- bis (1,3-dimethyl-ethyl) -4-hydroxy C7-C9 alkyl ester

Reference example 1

Production of an unstabilized prepolymer based on polypronylene oxide

A 1 L four-necked flask with gas inlet, reflux condenser, stirrer and dropping funnel was initially charged with 361 g of isocyanate 1, pressurized with nitrogen and heated to 80 ° C. with stirring. A polyol mixture consisting of 92.8 g of polyol 1, 12.5 g of polyol 3, 33.6 g of polyol 4 and 0.48 g of Irganox 1135 was added to this solution so that the temperature did not exceed 80.degree. After the addition was complete, the mixture was stirred at 80 ° C. for 2 hours.

Reference example 2

Production of an unstabilized prepolymer based on POM-PO block copolymers

A 6 L four-necked flask with gas inlet, reflux condenser, stirrer and dropping funnel was initially charged with 3560 g of isocyanate 1 and 50 g of isocyanate 2, charged with nitrogen and heated to 80 ° C. with stirring. A polyol mixture consisting of 925 g of polyol 2, 125 g of polyol 3, 335 g of polyol 4 and 4.8 g of Irganox 1135 was added to this solution so that the temperature did not exceed 80.degree. After the addition was complete, the mixture was stirred at 80 ° C. for 2 hours.

Reference example 3

Production of a CPA-stabilized prepolymer based on POM-PO block copolymers In a 6 L four-necked flask with gas inlet, reflux condenser, stirrer and dropping funnel, 4327 g of isocyanate 1 were placed, subjected to nitrogen and heated to 80 ° C. with stirring. A polyol mixture consisting of 1113 g of polyol 2, 150 g of polyol 3, 403 was added to this solution g polyol 4 and 5.7 g Irganox 1135 as well as 0.6 g CPA were added so that the temperature does not exceed 80 ° C. After the addition was complete, the mixture was stirred at 80 ° C. for 2 hours.

Example 4 (according to the invention)

Production of an HCl-stabilized prepolymer based on POM-PO block copolymers In a 4 L four-necked flask with gas inlet, reflux condenser, stirrer and dropping funnel, 2113 g of isocyanate 1, 30 g of isocyanate 2 and 23.4 g of isocyanate 3 were placed, with nitrogen applied and heated to 80 ° C with stirring. A polyol mixture consisting of 555 g of polyol 2, 75 g of polyol 3, 210 g of polyol 4 and 3.0 g of Irganox 1135 was added to this solution so that the temperature did not exceed 80.degree. After the addition was complete, the mixture was stirred at 80 ° C. for 2 hours.

Example 5 (according to the invention)

Preparation of a CPA-stabilized prepolymer based on POM-PO block copolymers In a 500 mL four-necked flask with gas inlet, reflux condenser, stirrer and dropping funnel, 356 g of isocyanate 1 and 5.0 g of isocyanate 2 were placed, charged with nitrogen and stirred up 80 ° C heated. A polyol mixture consisting of 92.3 g of polyol 2, 12.5 g of polyol 3, 33.4 g of polyol 4, 0.5 g of Irganox 1135 and 0.5 g of CPA was added to this solution, so that the temperature was 80 ° C does not exceed. After the addition was complete, the mixture was stirred at 80 ° C. for 2 hours.

Example 6 (according to the invention)

Production of a DBP-stabilized prepolymer based on POM-PO block copolymers In a 4 L three-necked flask with gas inlet, reflux condenser, stirrer and dropping funnel, 1795 g of isocyanate 1 and 2.4 g of isocyanate 2 were placed, charged with nitrogen and stirred up 80 ° C heated. A polyol mixture consisting of 466 g of polyol 2, 63.1 g of polyol 3, 169 g of polyol 4, 2.4 g of Irganox 1135 and 1.5 g of DBP was added to this solution so that the temperature does not exceed 80.degree . After the addition was complete, the mixture was stirred at 80 ° C. for 2 hours.

Storage stability of the prepolymers

The prepolymers obtained in Examples 1-5 were stored for 3 days at 80 ° C. under a nitrogen atmosphere. The dynamic viscosity and the NCO value of the prepolymers before and after aging are shown in Table 1. The prepolymer should have an NCO content of 15 to 25% by weight and a dynamic viscosity at 50 ° C. 100 to 500 mPa * s.

The quantities given in Table 1 below are in% by weight based on the sum of the mass of all components. ü _Met (DMC) = molar amount of substance of the metals of the double metal cyanide catalyst determined according to DIN - ISO 17025 (August 2005)

n (C) = molar amount of substance of component C.

Table 1: Composition and properties of the prepolymers

With the storage conditions in the examples presented above, storage of 6 months at a temperature of 25 ° C. under a protective gas atmosphere was simulated.

The reference prepolymer 2 contains a polyoxymethylene-polyoxyalkylene block copolymer, but no acid. This example shows that prepolymers based on a polyoxymethylene-polyoxyalkylene block copolymer without an acid have a dynamic viscosity that is too high to be used in a manufacturing process for a polyurethane, especially if a quick filling of a mold before the components are allowed to react got to. In addition, prepolymer 2 has too low an NCO content, in particular after storage.

The prepolymers 4, 5 and 6 according to the invention are prepolymers which contain a polyoxymethylene-polyoxyalkylene block copolymer and an acid in the range according to the invention. These prepolymers have a sufficiently low dynamic viscosity to be used for the production of a polyurethane integral foam. This is especially true for the dynamic viscosity after storage. The NCO content is also sufficiently high, especially after storage, so that the prepolymer has sufficient reactivity for the reaction with a polyol component to form a polyurethane. The prepolymers 4, 5 and 6 according to the invention have a reactivity comparable to that of the reference prepolymer 1. The reference prepolymer 1 does not contain a polyoxymethylene-polyoxyalkylene block copolymer and corresponds to a polyether-based prepolymer customarily used for the production of integral polyurethane foams.

Synthesis of polyurethane integral skin foams

The prepolymers 1 to 5 were processed together with a polyol component to form integral polyurethane foams.

The following starting materials were used for the synthesis of the polyurethane integral skin foams:

- Prepolymers from Ex. 4 and 6 as described above

Bayflex S 99-312, commercial product from Covestro Deutschland AG, polyol mixture with a hydroxyl number according to DIN 53240-1: 2013-06 of 171 mg KOH / g, Bayflex S 99-312 does not contain any polyoxymethylene-polypropylene oxide block copolymer

Desmodur 0960, commercial product from Covestro Deutschland AG, isocyanate mixture with an NCO content according to EN ISO 11909 (2007) of 20.4% Desmodur 0960 does not contain a prepolymer with a polyoxymethylene-polypropylene oxide block copolymer Table 2: Composition of the polyurethane integral skin foams

The properties of the prepolymers during synthesis and the mechanical properties of the integral polyurethane foam obtained were investigated. The results are summarized in Table 2.

Table 3: Properties of the polyurethane integral skin foams

Claims

1. A process for the production of a prepolymer for the production of a polyurethane integral skin foam, the prepolymer being obtained or being obtainable by reacting a composition containing or consisting of the following components:

Component A containing or consisting of

0.04 to 1.0% by weight, based on the composition, of a protic acid as

Component C,

and optionally a component D containing auxiliaries,

with a code from 450 to 850.

2. The method according to claim 1, characterized in that component Al consists of a polyoxymethylene-polypropylene oxide block copolymer or a polyoxymethylene-polyoxyalkylene carbonate block copolymer, the block copolymer preferably having two terminal polyoxyalkylene blocks.

3. The method according to claim 1 or 2, characterized in that at least component Al was prepared in the presence of a double metal cyanide catalyst and component Al still contains this double metal cyanide catalyst at least partially, the content of double metal cyanide catalyst based on component A 10 up to 5000 ppm, preferably 1000 to 2500 ppm, and the content of double metal cyanide Catalyst based on the amount of metal content of the double metal cyanide catalyst determined according to DIN-ISO 17025 (August 2005).

4. The method according to claim 3, characterized in that the amount used

Component C is selected in such a way that the molar amount of substance of the metals of the double metal cyanide catalyst n _Met (DMC) determined according to DIN - ISO 17025 (August 2005) for the molar amount of substance of component C n (C) follows the relationship: n _Met (DMC) F = n (C), where f is a number from 1.0 to 20.0, preferably from 1.2 to 10.0, more preferably from 3.0 to 6.0, particularly preferably from 3.5 to 5 , 0, is.

5. The method according to any one of the preceding claims, characterized in that

Component Al has a hydroxyl number according to DIN 53240-2 (November 2007) of 30 mg KOH / g to 150 mg KOH / g, preferably 40 mg KOH / g to 100 mg KOH / g.

6. The method according to any one of the preceding claims, characterized in that

Component A2 is a polyether polyol, polyester polyol, polyether ester polyol,

Contains or consists of polycarbonate polyol or polyacrylate polyol or mixtures thereof, component A2 preferably containing or consisting of a branched polypropylene oxide.

7. The method according to any one of the preceding claims, characterized in that

Component A3 Diethanolamine, Ethylenediamine, Glycerine, Triproyleneglycol,

Contains or consists of trimethylol propane or mixtures thereof, with component A3 preferably containing or consisting of tripylene glycol.

8. The method according to any one of the preceding claims, characterized in that

Component B contains carbodiimide-modified diisocyanates with an NCO content according to EN ISO 11909 (2007) of 20 to 50% by weight based on the carbodiimide-modified diisocyanates.

9. The method according to any one of the preceding claims, characterized in that

Component C is an inorganic acid, a carboxylic acid, a halogenated carboxylic acid, a dicarboxylic acid, a hydroxycarboxylic acid, a sulfonic acid, a phosphoric acid or is a phosphoric acid derivative, component C preferably being dibutyl phosphate, hydrochloric acid or 2-chloropropionic acid.

10. The method according to any one of the preceding claims, characterized in that of component C 0.04 to 0.5 wt .-%, preferably 0.04 to 0.3 wt .-%, each based on the composition, in the composition are included.

11. The method according to any one of the preceding claims, characterized in that the prepolymer is obtained or is obtainable by reacting a composition containing or consisting of

- 10.50% by weight to 30.50% by weight of component Al,

- 0.50% by weight to 3.50% by weight of component A2,

- 1.00% by weight to 8.00% by weight of component A3,

- 67.85% by weight to 77.65% by weight of component B,

- 0.05 to 0.2% by weight of component C,

- 0.10 to 0.20% by weight of component D,

12. Prepolymer, obtained by or obtainable by a process according to any one of claims 1 to 11.

13. Polyurethane integral skin foam, obtained by or obtainable by reacting a composition containing or consisting of

- a prepolymer according to any one of claim 12,

- optional auxiliaries and additives,

with a code from 85 to 110.

14. Use of a prepolymer according to claim 12 or a polyurethane integral foam according to claim 13 for the production of shoe soles, in particular for the production of shoe soles for sports shoes or hiking boots.