WO2022175210A1

WO2022175210A1 - Method for producing polyurethane foam

Info

Publication number: WO2022175210A1
Application number: PCT/EP2022/053554
Authority: WO
Inventors: Joerg Hofmann; Veronica-Alina FAERBER; Stefanie Braun; Michael Traving
Original assignee: Covestro Deutschland Ag
Priority date: 2021-02-16
Filing date: 2022-02-15
Publication date: 2022-08-25

Abstract

The present invention relates to a method for producing polyurethane foams, wherein the components (A) containing (A1) compounds with hydrogen atoms capable of reacting with isocyanates, including (A1.1) polyether carbonate polyol, (A2) propellant and, where appropriate, (A3) adjutants and additives, and (B) di-isocyanates and/or polyisocyanates are reacted with one another, characterized in that the structure of A1.1 is built from a starter compound S1 having a molecular weight from 18 to 200 g/mol on which a first, inner alkylene oxide block containing 0.5 to 30 wt% ethylene oxide structural units, relative to the total mass of alkylene oxide used in the first alkylene oxide block, and a second, outer block of carbon dioxide and alkylene oxide are deposited.

Description

Process for the production of polyurethane foam

The present invention relates to a process for producing polyurethane foams, preferably flexible polyurethane foams, by reacting an isocyanate component with an isocyanate-reactive component which comprises at least one polyether carbonate polyol. The invention further relates to polyurethane foams produced by the process according to the invention and their use, as well as the polyether carbonate polyol used according to the invention.

In the context of an environmentally friendly orientation of production processes, it is generally desirable to use CCE-based starting materials, for example in the form of polyether carbonate polyols, in relatively large quantities. The production of polyether carbonate polyols by catalytic conversion of alkylene oxides (epoxides) and carbon dioxide in the presence of H-functional starter compounds ("starters") has been intensively studied for more than 50 years (e.g. Inoue et al, Copolymerization of Carbon Dioxide and Epoxide with Organometallic Compounds; Die Makromolecular Chemie 130, 210-220, 1969). This reaction is shown schematically in Scheme (I), where R is an organic radical such as alkyl, alkylaryl or aryl, each of which may also contain heteroatoms such as O, S, Si, etc., and where e, f and g are a are integers, and the product shown here in scheme (I) for the polyethercarbonate polyol should only be understood in such a way that blocks with the structure shown can in principle be found again in the polyethercarbonate polyol obtained, the order, number and length of the blocks and the OH However, functionality of the initiator can vary and is not limited to the polyethercarbonate polyol shown in Scheme (I). This reaction (see scheme (I)) is ecologically very advantageous since this reaction represents the conversion of a greenhouse gas such as CO2 into a polymer. The cyclic carbonate shown in scheme (I) is formed as a further product, actually a by-product (for example for R=CH3 propylene carbonate, also referred to below as cPC, or for R=H ethylene carbonate, also referred to below as cEC).

Starter + (e+g) C0 ₂ -

The production of polyurethane foams based on polyether carbonate polyols and isocyanates is known (eg WO 2012/130760 A1, WO 2015/078801). Important when using Such polyurethane foams include resistance to mechanical influences in order to achieve a long service life for the polyurethane foams.

The object of the present invention was therefore to provide a process for producing polyurethane foams comprising polyether carbonate polyols, which leads to polyurethane foams having a higher tensile strength and elongation at break.

Surprisingly, this object has been achieved by a process for the production of polyurethane foams, the components A containing

Al compounds with isocyanate-reactive hydrogen atoms, containing Al.l polyether carbonate polyol,

A2 propellants and optionally A3 auxiliaries and additives and

B di- and/or polyisocyanates, are reacted with one another, characterized in that the structure of Al.l is made up of a starter compound S 1 having a molecular weight of 18 to 200 g/mol on which a first, inner alkylene oxide block containing 0.5 up to 30 wt.

The preferred subject matter of the invention is a process for producing polyurethane foams, preferably flexible polyurethane foams, characterized in that component A1 has the following composition:

Al.l 40 to 100 parts by weight polyether carbonate polyol, preferably with a hydroxyl number according to DIN 53240-1 (June 2013) of 20 mg KOH/g to 120 mg KOH/g,

A1.2 0 to 60 parts by weight of polyether polyol with a hydroxyl number according to DIN 53240-1 (June 2013) of 20 mg KOH/g to 250 mg KOH/g and an ethylene oxide content of 0 to 60% by weight, where Polyetherpolyol Al.2 is free of carbonate units,

A1.3 0 to 20 parts by weight of polyether polyol with a hydroxyl number according to DIN 53240-1 (June 2013) of 20 mg KOH/g to 250 mg KOH/g and an ethylene oxide content of >60% by weight, where Polyetherpolyol Al .3 is free of carbonate units,

A1.4 0 to 40 parts by weight polymer polyol, PHD polyol and/or PIPA polyol,

A1.5 0 to 40 parts by weight of a polyol which does not fall under the definition of components Al.1 to Al.4, where the parts by weight are given in each case based on the sum of the parts by weight of the

Components A1.1 + A1.2 + A1.3 + A1.4 + A1.5 = 100 parts by weight.

The components A1.1 to A1.5 each refer to “one or more” of those mentioned

Links. When using several connections of a component corresponds to the

Quantities of the sum of the parts by weight of the compounds.

In a particularly preferred embodiment, component contains Al

Al.l> 65 to <75 parts by weight, most preferably> 68 to <72 parts by weight, of one or more polyether carbonate polyols, preferably with a hydroxyl number according to DIN 53240-1 (June 2013) of> 20 mg KOH/g to <120 mg KOH/g and preferably a CO ₂ content of 10 to 25% by weight, and

A1.2 <35 to >25 parts by weight, most preferably <32 to >28 parts by weight of one or more

Polyether polyols with a hydroxyl number according to DIN 53240-1 (June 2013) of >20 mg KOH/g to <250 mg KOH/g and an ethylene oxide content of >0 to <60% by weight, the polyether polyols Al.2 free are of carbonate units, with component Al preferably being free from component Al.3 and/or Al.4.

In another embodiment, component includes Al

Al.l> 65 to <75 parts by weight, preferably> 68 to <72 parts by weight, of one or more polyether carbonate polyols, preferably with a hydroxyl number according to DIN 53240-1 (June 2013) of> 20 mg KOH/g to < 120 mg KOH/g and preferably a C0 ₂ content of 10 to 25% by weight, and

A1.2 <35 to >25 parts by weight, preferably <32 to >28 parts by weight, of one or more

Polyether polyols with a hydroxyl number according to DIN 53240-1 (June 2013) of >20 mg KOH/g to <250 mg KOH/g and an ethylene oxide content of >0 to <60% by weight, the polyether polyols Al.2 free are of carbonate units,

A1.3 <20 to> 2 parts by weight, preferably <10 to> 2 parts by weight, based on the sum of

Parts by weight of components Al.l and A1.2, one or more polyether polyols with a hydroxyl number according to DIN 53240-1 (June 2013)> 20 mg KOH / g to <250 mg KOH / g, and an ethylene oxide content of >60% by weight, the polyether polyols A1.3 being free from carbonate units, with component A1 preferably being free from component A1.4.

In another embodiment, component includes Al

Al.l >40 to <100 parts by weight, preferably >60 to <100 parts by weight, particularly preferably >80 to <100 parts by weight, most preferably >65 to <75 parts by weight of one or more Polyethercarbonate polyols, preferably with a hydroxyl number according to DIN 53240-1 (June 2013) from > 20 mg KOH/g to <120 mg KOH/g and preferably a CO ₂ content of 10 to 25% by weight, and

A1.2 <60 to >0 parts by weight, preferably <40 to >0 parts by weight, particularly preferably <20 to >

0 parts by weight, most preferably <35 to >25 parts by weight, of one or more polyether polyols with a hydroxyl number according to DIN 53240-1 (June 2013) of >20 mg KOH/g to <250 mg KOH/g and a content of ethylene oxide from >0 to <60% by weight, the polyether polyols Al.2 being free from carbonate units,

A1.4 <40 to >0.01 parts by weight, preferably <20 to >0.01 parts by weight, particularly preferably <20 to >1 part by weight, most preferably <20 to >2 parts by weight Parts, based on the sum of the parts by weight of components A1.1 and A1.2, of one or more polymer polyols, PHD polyols and/or PIPA polyols,

A1.5 <40 to >0 parts by weight, based on the sum of the parts by weight of components Al.l and A1.2, polyols that do not fall under the definition of components Al.l to A1.4, where component Al is preferably free from component Al.3.

The specified ranges and preferred ranges of components A1.1, A1.2, A1.4 and A1.5 can be freely combined with one another.

The components used in the method according to the invention are described in more detail below.

component Al

Component A1 includes compounds with isocyanate-reactive hydrogen atoms and, according to the invention, contains at least one polyether carbonate polyol A1.1. The polyether carbonate polyol A1.1 is based on a starter compound S1 with a molecular weight of 18 to 200 g/mol, a first, inner alkylene oxide block containing 0.5 to 30% by weight of ethylene oxide, based on the total mass of alkylene oxide in the first alkylene oxide block, and a second, outer block of carbon dioxide and alkylene oxide.

Starter compound S1 with a molecular weight of 18 to 200 g/mol is understood as meaning compounds which have H atoms which are active towards alkoxylation, for example monohydric or polyhydric alcohols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1, 4-butanediol, 1,5-pentanediol, 2-methylpropane-1,3-diol, neopentyl glycol, 1,6-hexanediol, 1,8-octanediol, diethylene glycol, dipropylene glycol, glycerine, trimethylolpropane, pentaerythritol and sorbitol. Mixtures of different starter compounds S1 can also be used.

A first, inner alkylene oxide block is attached to the starter compound S 1 with a molecular weight of 18 to 200 g/mol. The first, inner alkylene oxide block consists of at least two alkylene oxides and contains 0.5 to 30% by weight of ethylene oxide, preferably 1 to 25% by weight, in particular preferably 5 to 22% by weight, particularly preferably 12 to 22% by weight, based in each case on the total mass of the alkylene oxide used in the first alkylene oxide block. The first, inner alkylene oxide block preferably consists only of ethylene oxide and propylene oxide.

A second, outer block of carbon dioxide and alkylene oxide is attached to the first inner alkylene oxide block. The alkylene oxide used for the second block is preferably propylene oxide, ethylene oxide or a mixture of both, particularly preferably at least 90% by weight of propylene oxide, very particularly preferably just propylene oxide.

The polyether carbonate polyol A1.1 is obtained, for example, by a process comprising the steps

(i) Addition of alkylene oxide containing 0.5 to 30% by weight of ethylene oxide to form a first alkylene oxide block onto a starter compound S 1 having a molecular weight of 18 to 200 g/mol, preferably in the presence of a DMC catalyst, resulting in an alkylene oxide polymer ,

(ii) adding carbon dioxide and alkylene oxide, preferably in the presence of a DMC catalyst, to the alkylene oxide polymer resulting from (i) to form a polyethercarbonate polyol.

Steps (i) and (ii) are preferably carried out in the presence of a DMC catalyst, such as DMC catalysts based on zinc hexacyanocobaltate(III), zinc hexacyanoiridate(III), zinc hexacyanoferrate(III) and cobalt(II) hexacyanocobaltate(III) . A DMC catalyst based on zinc hexacyanocobaltate (Zm|Co(CN)r,|2) is preferably used. However, metal complex catalysts based on the metals zinc and/or cobalt can also be used for the copolymerization of alkylene oxide and carbon dioxide in step (ii). This includes in particular so-called zinc glutarate catalysts (described e.g. in M. H. Chisholm et al., Macromolecules 2002, 35, 6494), so-called zinc diiminate catalysts (described e.g. in S. D. Allen, J. Am. Chem. Soc. 2002, 124, 14284), so-called cobalt salen catalysts (described e.g. in US Pat. No. 7,304,172 B2, US 2012/0165549 A1) and bimetallic zinc complexes with macrocyclic ligands (described e.g. in M. R. Kember et al., Angew. Chem., Int. Ed., 2009, 48, 931). KOH, for example, can also be used for the addition reaction of alkylene oxide onto the starter compound S1 in step (i).

Steps (i) and (ii) can be carried out directly one after the other or separately from one another. For example, the alkylene oxide polymer obtained from step (i) can be purified before carbon dioxide and alkylene oxide are added to the alkylene oxide polymer in step (ii). A purification step is advantageous, for example, when different catalysts are used in steps (i) and (ii). However, it can also be a DMC Catalyst are used in step (i) and left in the resulting alkylene oxide polymer and function as a catalyst in step (ii).

The alkylene oxide polymer resulting from step (i) preferably has a molecular weight of 250 to 2000 g/mol, preferably 400 to 1200 g/mol, particularly preferably 500 to 1000 g/mol.

In a preferred embodiment, step (ii) is carried out as follows:

(a) the alkylene oxide polymer from step (i) is initially taken and, if appropriate, water and/or other readily volatile compounds are removed by elevated temperature and/or reduced pressure ("drying"), with a catalyst being optionally used before or after drying to give the alkylene oxide polymer from step (i) is added,

(ß) optionally, to activate a DMC catalyst, a portion (based on the total amount of alkylene oxides used in the activation and copolymerization in step (ii)) of alkylene oxide is added to the mixture resulting from step (a), this addition a subset of alkylene oxide can optionally take place in the presence of CO2, and the temperature peak ("hotspot") occurring as a result of the following exothermic chemical reaction and/or a drop in pressure in the reactor is then awaited in each case, and step (ß) for activation also can be done multiple times

(g) Alkylene oxide and carbon dioxide are added to the mixture resulting from step (a) or optionally (β), it being possible for the alkylene oxides used in step (β) to be the same as or different from the alkylene oxides used in step (g).

The polyether carbonate polyol Al.1 used according to the invention preferably has a hydroxyl number (OH number) according to DIN 53240-1 (June 2013) from 20 mg KOH/g to 120 mg KOH/g, preferably from 20 mg KOH/g to 100 mg KOH/g g, particularly preferably from 25 mg KOH/g to 90 mg KOH/g. The polyether carbonate polyol Al.l preferably has a CO ₂ content of 10 to 25% by weight, preferably 12 to 20% by weight. The functionality of the polyether carbonate polyol Al.l is preferably from 1 to 6, preferably from 1 to 4, particularly preferably from 2 to 3.

The proportion of built-in CO2 (“units originating from carbon dioxide”; “C0 ₂ content”) in a polyether carbonate polyol can be determined from the evaluation of characteristic signals in the 'HN R spectrum. The example below illustrates the determination of the level of carbon dioxide derived units in a CCE/propylene oxide polyethercarbonate polyol initiated on 1,8-octanediol.

The proportion of built-in CO2 in a polyether carbonate polyol and the ratio of cyclic carbonate to polyether carbonate polyol can be determined using Ή-NMR (a suitable device is from Bruker, DPX 400, 400 MHz; pulse program zg30, waiting time dl: 10 s, 64 scans). will. In each case, the sample is dissolved in deuterated chloroform. The relevant resonances in the Ή-NIVIR (relative to TMS = 0 ppm) are as follows:

Cyclic carbonate (which was formed as a by-product) resonating at 4.5 ppm; carbonate resulting from carbon dioxide incorporated in the polyethercarbonate polyol with resonances at 5.1 to 4.8 ppm; unreacted propylene oxide (PO) resonating at 2.4 ppm; polyether polyol (i.e., without incorporated carbon dioxide) with resonances at 1.2 to 1.0 ppm; the 1.8 octanediol incorporated as a starter molecule (if present) with a resonance at 1.6 to 1.52 ppm.

The weight fraction (in % by weight) of polymer-bound carbonate (LC') in the reaction mixture was calculated according to formula (II),

[ (5,l - 4,8) - (4,5)]* 102

where the value for N ("denominator" N) is calculated according to formula (III):

N = [F(5,l - 4,8) - F(4,5)]* 102 + F(4,5) * 102 + F(2,4) * 58 + 0.33 * F(l, 2 - 1.0) * 58 + 0.25 * F(l.6 - 1.52) * 146

(iii)

The following abbreviations apply:

F(4.5) = area of resonance at 4.5 ppm for cyclic carbonate (corresponds to an H atom)

F(5,1-4.8) = area of resonance at 5.1-4.8 ppm for polyethercarbonate polyol and one H for cyclic carbonate.

F(2,4) = area of resonance at 2.4 ppm for free unreacted PO F(1.2-1.0) = area of resonance at 1.2-1.0 ppm for polyether polyol

F(1,6-1.52) = area of resonance at 1.6 to 1.52 ppm for 1,8 octanediol (initiator) if present.

The factor 102 results from the sum of the molar masses of CO2 (molar mass 44 g/mol) and that of propylene oxide (molar mass 58 g/mol), the factor 58 results from the molar mass of propylene oxide and the factor 146 results from the molar mass of the starter used 1,8-octanediol (if available).

The weight fraction (in % by weight) of cyclic carbonate (CC') in the reaction mixture was calculated according to formula (IV), where the value for N is calculated according to formula (III).

In addition, component A1 can contain other compounds with hydrogen atoms that are reactive toward isocyanates. Component A1.2 comprises polyether polyols with a hydroxyl number according to DIN 53240-1 (June 2013) from 20 mg KOH/g to 250 mg KOH/g, preferably from 20 to 112 mg KOH/g and particularly preferably 20 mg KOH/g 80 mg KOH/g and is free of carbonate units. The compounds according to A1.2 can be prepared by catalytic addition of one or more alkylene oxides onto H-functional starter compounds.

Alkylene oxides having 2 to 24 carbon atoms can be used as alkylene oxides (epoxides). The alkylene oxides having 2 to 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 polyepoxidized fats as mono-, di- and triglycerides, epoxidized fatty acids, Ci-C24 esters of epoxidized fatty acids, epichlorohydrin, glycidol, and derivatives of glycidol, such as methyl glycidyl ether, ethyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, glycidyl methacrylate and epoxy-functional alkoxy silanes, such as 3-glycidyloxypropyltrimethoxy silane, 3-glycidyloxypropyltriethoxy silane, 3-

glycidyloxypropyltripropoxysilane, 3 -glycidyloxypropylmethyldimethoxysilane, 3 -

glycidyloxypropylethyldiethoxysilane, 3-glycidyloxypropyltriisopropoxysilane. Ethylene oxide and/or propylene oxide and/or 1,2-butylene oxide are preferably used as alkylene oxides. The alkylene oxides can be added to the reaction mixture individually, as a mixture or in succession. They can be random or block copolymers. If the alkylene oxides are metered in one after the other, the products produced (polyether polyols) contain polyether chains with block structures.

The H-functional starter compounds have functionalities from 2 to 6 and are preferably hydroxy-functional (OH-functional). Examples of hydroxy-functional starter compounds are propylene glycol, ethylene glycol, diethylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, hexanediol, pentanediol, 3-methyl-1,5-pentanediol, 1,12- Dodecanediol, glycerin, trimethylolpropane, triethanolamine, pentaerythritol, sorbitol, sucrose, hydroquinone, catechol, resorcinol, bisphenol F, bisphenol A, 1,3,5-trihydroxybenzene, methylol-containing condensates of formaldehyde and phenol or melamine or urea. These can also be used in a mixture. 1,2-Propylene glycol and/or glycerol and/or trimethylolpropane and/or sorbitol is preferably used as the starter compound.

The polyether polyols of component A1.2 contain from 0 to 60% by weight, preferably from 0 to 40% by weight, particularly preferably from 0 to 25% by weight, of ethylene oxide.

Component A1.3 comprises polyether polyols with a hydroxyl number according to DIN 53240-1 (June 2013) from 20 mg KOH/g to 250 mg KOH/g, preferably from 20 to 112 mg KOH/g and particularly preferably 20 mg KOH/g 80 mg KOH/g.

In principle, component A1.3 is prepared analogously to component A1.2, but with an ethylene oxide content of >60% by weight, preferably >65% by weight, being set in the polyether polyol.

Suitable alkylene oxides and H-functional starter compounds are the same as described for component A1.2.

However, suitable H-functional starter compounds are preferably those which have a functionality of 3 to 6, particularly preferably 3, so that polyether triols are formed. Preferred starter compounds with a functionality of 3 are glycerol and/or trimethylolpropane, with glycerol being particularly preferred.

In a preferred embodiment, component A1.3 is a glycerol-started trifunctional polyether with an ethylene oxide content of 68 to 73% by weight and an OH number of 35 to 40 mg KOH/g.

Component A1.4 includes polymer polyols, PHD polyols and PIPA polyols.

Polymer polyols are polyols containing proportions of solid polymers produced by free radical polymerization of suitable monomers such as styrene or acrylonitrile in a base polyol such as a polyether polyol and/or polyether carbonate polyol.

PHD (polyurea dispersion) polyols are prepared, for example, by in situ polymerization of an isocyanate or an isocyanate mixture with a diamine and/or hydrazine in a polyol, preferably a polyether polyol. The PHD dispersion is preferably prepared by reacting an isocyanate mixture used from a mixture of 75 to 85% by weight of 2,4-tolylene diisocyanate (2,4-TDI) and 15 to 25% by weight of 2,6-tolylene diisocyanate (2.6 TDI) with a Diamine and/or hydrazine in a polyether polyol, preferably a polyether polyol and/or polyether carbonate polyol prepared by alkoxylating a trifunctional starter (such as glycerol and/or trimethylolpropane) in the presence of carbon dioxide in the case of the polyether carbonate polyol. Processes for preparing PHD dispersions are described, for example, in US Pat. Nos. 4,089,835 and US 4,260,530.

The PIPA polyols are polyether polyols and/or polyether carbonate polyols modified by polyisocyanate polyaddition with alkanolamines, preferably triethanolamine-modified, the polyether carbonate polyol having a functionality of 2.5 to 4 and a hydroxyl number of 3 mg KOH/g to 112 mg KOH/g (molecular weight 500 to 18,000). Preferably, the polyether polyol is "EO-capped", i.e. the polyether polyol has terminal ethylene oxide groups. PIPA polyols are described in detail in GB 2 072 204 A, DE 31 03 757 A1 and US Pat. No. 4,374,209.

All polyhydroxy compounds known to those skilled in the art that do not fall under the definition of components A1.1 to A1.4 and preferably have an average OH functionality of >1.5 can be used as component A1.5.

These can be, for example, low molecular weight diols (e.g. 1,2-ethanediol, 1,3- or 1,2-propanediol, 1,4-butanediol), triols (e.g. glycerol, trimethylolpropane) and tetraols (e.g. pentaerythritol), polyester polyols, polythioether polyols or Polyacrylate polyols and polyether polyols, polyether carbonate polyols or polycarbonate polyols which do not fall under the definition of components Al.1 to A1.4. For example, ethylenediamine and triethanolamine started polyethers can also be used.

Component A2

Blowing agents such as chemical and/or physical blowing agents are used as component A2.

Water or carboxylic acids and mixtures thereof, for example, are used as the chemical blowing agent A2.1. These react with isocyanate groups to form the propellant gas, for example in the case of water, carbon dioxide is formed and in the case of z. B. formic acid produces carbon dioxide and carbon monoxide. At least one compound selected from the group consisting of formic acid, acetic acid, oxalic acid and ricinoleic acid is preferably used as the carboxylic acid. Water is particularly preferably used as the chemical blowing agent.

For example, low-boiling organic compounds such as e.g. B. hydrocarbons, ethers, ketones, carboxylic acid esters, carbonic acid esters, halogenated hydrocarbons. Particularly suitable are organic compounds which are inert towards the isocyanate component B and have boiling points below 100° C., preferably below 50° C., at atmospheric pressure. These boiling points have the advantage that the organic compounds evaporate under the influence of the exothermic polyaddition reaction. Examples of such preferably used organic compounds are alkanes such as heptane, hexane, n- and isopentane, preferably technical mixtures of n- and isopentanes, n- and isobutane and propane, cycloalkanes such as cyclopentane and/or cyclohexane , Ethers such as furan, dimethyl ether and diethyl ether, ketones such as acetone and methyl ethyl ketone, carboxylic acid alkyl esters such as methyl formate, dimethyl oxalate and ethyl acetate and halogenated hydrocarbons such as methylene chloride, dichloromonofluoromethane, difluoromethane, trifluoromethane, difluoroethane, tetrafluoroethane, chlorodifluoroethane, 1,1-dichloro- 2,2,2-trifluoroethane, 2,2-dichloro-2-fluoroethane and heptafluoropropane. Also preferred is the use of (hydro)fluorinated olefins, such as HFO 1233zd(E) (trans-1-chloro-3,3,3-trifluoro-l-propene) or HFO 1336mzz(Z) (cis-l,l ,l,4,4,4-hexafluoro-2-butene) or additives such as FA 188 from 3M (l,l,l,2,3,4,5,5,5-nonafluoro-4-(trifluoromethyl)pent- 2-en). Mixtures of two or more of the organic compounds mentioned can also be used. The organic compounds can also be used in the form of an emulsion of small droplets.

In a particular embodiment, the component contains A2

A2.1 0.5 to 5 parts by weight (based on A=100 parts by weight) chemical blowing agents and/or

A2.2 0 to 15 parts by weight (based on A=100 parts by weight) of physical blowing agents Particular preference is given to using water as component A2.

Component A3

Auxiliaries and additives are used as component A3, such as a) catalysts (activators), b) surface-active additives (surfactants), such as emulsifiers and foam stabilizers, in particular those with low emissions such as products from the Tegostab ^® LF series, c) additives such as reaction retardants ( e.g. acidic substances such as hydrochloric acid or organic acid halides), cell regulators (such as paraffins or fatty alcohols or dimethylpolysiloxanes), pigments, dyes, flame retardants (such as tricresyl phosphate), stabilizers against aging and weathering, plasticizers, fungistatic and bacteriostatic substances, fillers (such as barium sulfate, kieselguhr, soot or whiting) and release agents. Preferred catalysts are aliphatic tertiary amines (e.g. trimethylamine, tetramethylbutanediamine), cycloaliphatic tertiary amines (e.g. 1,4-diaza(2,2,2)bicyclooctane), aliphatic amino ethers (e.g. dimethylaminoethyl ether and N,N,N-trimethyl-N- hydroxyethyl bisaminoethyl ether), cycloaliphatic amino ethers

(e.g. N-ethylmorpholine), aliphatic amidines, cycloaliphatic amidines, urea, derivatives of urea (such as aminoalkylureas), in particular (3-dimethylaminopropylamine)urea) and tin catalysts (such as dibutyltin oxide, dibutyltin dilaurate, tin octoate).

Particularly preferred catalysts are (i) urea, derivatives of urea and/or (ii) the abovementioned amines and amino ethers, characterized in that the amines and amino ethers contain a functional group which reacts chemically with the isocyanate. Preferably the functional group is a hydroxyl group, a primary or secondary amino group. These particularly preferred catalysts have the advantage that they have greatly reduced migration and emission behavior. Examples of particularly preferred catalysts are: (3-dimethylaminopropylamine)-urea, 1,1'-((3-

(dimethylamino)propyl)imino)bis-2-propanol, N-[2-[2-(dimethylamino)ethoxy]ethyl]-N-methyl-

1.3-propanediamine and 3-dimethylaminopropylamine.

Component B

Aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic polyisocyanates are used as component B, for example those of the formula (V)

Q(NCO)n (V) in which n is an integer between 2-4, preferably 2 or 3, and

Q is an aliphatic hydrocarbon radical having 2-18, preferably 6-10 carbon atoms, a cycloaliphatic hydrocarbon radical having 4-15, preferably 6-13 carbon atoms or an araliphatic hydrocarbon radical having 8-15, preferably 8-13 carbon atoms stands.

As a rule, the technically easily accessible polyisocyanates are particularly preferred, e.g

2,4- and 2,6-tolylene diisocyanate, and any mixtures of these isomers ("TDI"); Polyphenylpolymethylene polyisocyanates, such as those produced by aniline-formaldehyde condensation and subsequent phosgenation ("crude MDI") and polyisocyanates containing carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, urea groups or biuret groups ("modified polyisocyanates"), in particular those modified polyisocyanates which differ from 2,4- and/or 2,6-tolylene diisocyanate or from 4,4'- and/or 2,4'- diphenylmethane diisocyanate. Preferably, as component B at least one Compound selected from the group consisting of 2,4- and 2,6-tolylene diisocyanate, 4,4'- and 2,4'- and 2,2'-diphenylmethane diisocyanate and polyphenylpolymethylene polyisocyanate ("multi-core MDI") used.

A diphenylmethane diisocyanate mixture is very particularly preferably used as component B, consisting of a) 45 to 90% by weight of 4,4'-diphenylmethane diisocyanate and b) 10 to 55% by weight of 2,2'-diphenylmethane diisocyanate and/or 2 ,4'-diphenylmethane diisocyanate and c) 0 to 45 wt. or pMDI-based carbodiimides, uretdiones or uretdionimines.

In an alternative, very particularly preferred embodiment, a diphenylmethane diisocyanate mixture is used as component B, consisting of a) 35 to 45% by weight of 4,4'-diphenylmethane diisocyanate and b) 1 to 5% by weight of 2,2'-diphenylmethane diisocyanate and/or 2,4'-diphenylmethane diisocyanate and c) 50 to 64% by weight of polyphenyl polymethylene polyisocyanate ("multi-core MDI") and/or 2,2'-, 2,4'-, 4,4'-diphenylmethane diisocyanate -, and/or pMDI-based carbodiimides, uretdione or uretdione imines.

Component K

If appropriate, a component K can also be used in order to reduce the proportion of cyclic carbonates in the polyurethane foam. Examples of components K which can be used are: a) esters of monobasic or polybasic carboxylic acids, the pKa values of the (first) dissociation of the carboxylic acids being 0.5 to 4.0, such as methyl and ethyl esters of oxalic acid and/or malonic acid , b) mono-, di- and polysulfonates of mono- and polyfunctional alcohols, such as para-

Methyl toluenesulfonate and/or mixtures of (C10-

C21) Alkanesulfonic acid phenyl esters, c) esters of phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, phosphonous acid and phosphinous acid, such as, for example, phosphoric acid triethyl ester and alkoxylated phosphoric acid d) oligomeric alkyl phosphates.

Component K is preferably used in the process according to the invention in a proportion of 0.01 to 10.00 parts by weight, based on the sum of the parts by weight of component Al.1+A1.2 = 100 parts by weight used. It is preferred that component K is present in a proportion of 0.01 to 8.00 parts by weight, particularly preferably 0.05 to 6.00 parts by weight, particularly preferably 0.1 to 6.00 parts by weight -Tie., based in each case on the sum of the parts by weight of component Al.1+A1.2=100 parts by weight.

The polyurethane foams obtained according to the invention are preferably flexible polyurethane foams or semirigid polyurethane foams. To produce the polyurethane foams, the reaction components are reacted by the known one-step process, the prepolymer process or the semiprepolymer process, mechanical equipment often being used.

The polyurethane foams can be produced as molded foams or also as block foams, it being possible for the molded foams to be produced in a hot-curing or cold-curing manner.

The invention therefore relates to a process for producing the polyurethane foams, the polyurethane foams produced by this process and their use.

The polyurethane foams obtainable according to the invention are used, for example, in the following areas: furniture upholstery, textile inserts, mattresses, automobile seats, headrests, armrests, sponges and components, as well as seat and instrument paneling, and can have indexes of 60 to 250, preferably 70 to 120, particularly preferably 75 to 120 and bulk densities of 4 to 600 kg/m ³ , preferably 60 to 120 kg/m ³ (semi-rigid foam) or preferably 15 to 55 kg/m ³ (flexible foam).

The isocyanate number (also called number 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, these are the values at 25°C.

The preferred flexible polyurethane foams preferably have a bulk density according to DIN EN ISO 3386-1-98 in the range from 15 to 55 kg/m 3 , preferably from 20 to 50 kg/m ³ . examples

The invention is explained in more detail using the examples below, but without being restricted thereto.

Test methods:

The compressive strength of the polyurethane foams was determined according to DIN EN ISO 3386-1 in the September 2010 version in the direction of foaming and the bulk density according to DIN EN ISO 845 in the October 2009 version.

The compression set (DVR) was measured according to DIN EN ISO 1856 in the January 2008 version with 90% compression set at 70°C for 22 hours.

The values for tensile strength and elongation at break were determined at 22°C and 48% relative humidity in accordance with DIN EN ISO 1798 in the April 2008 version.

The OH numbers (hydroxyl numbers) were determined in accordance with the provisions of DIN 53240-1 (June 2013).

The emissions in the flexible polyurethane foams were determined in accordance with the LGA Pollutant Tested certification. The emissions were measured after conditioning the sample in the test chamber for 7 days. Test chamber conditions: 23°C±1°C, area-specific air flow rate: 0.5 m ³ /(m ² -h) ± 0.05 m ³ /(m ² -h) and rel. Humidity 50%±3%.

Raw materials:

AO polymer 1 Alkylene oxide polymer based on a propylene glycol/glycerol mixture and addition of 90% by weight of propylene oxide and 10% by weight of ethylene oxide, based in each case on the total mass of the alkylene oxide used, functionality of 2.8 and molecular weight of 670 g/ mol produced by DMC catalysis

AO-Polymer 2 Alkylene oxide polymer based on a propylene glycol/glycerol mixture and addition of 80% by weight of propylene oxide and 20% by weight of ethylene oxide, based in each case on the total mass of the alkylene oxide used, functionality of 2.8 and molecular weight of 670 g/ mol produced by DMC catalysis

AO polymer 3 Alkylene oxide polymer based on a propylene glycol/glycerol mixture and addition of 100% by weight of propylene oxide, based on the total mass of the alkylene oxide used, functionality of 2.8 and molecular weight of 670 g/mol, produced by DMC catalysis

Al.1-1 polyether carbonate polyol based on AO polymer 1 and subsequent addition of carbon dioxide and 100% by weight of propylene oxide, functionality of 2.8, OH number of 55 mg KOH/g, CO ₂ content of 14% by weight, produced by DMC catalysis

Al.1-2 polyether carbonate polyol based on AO polymer 2 and subsequent addition of carbon dioxide and 100% by weight of propylene oxide, functionality of 2.8, OH number of 55 mg KOH/g, CCE content of 14% by weight % produced by DMC catalysis

Al.5-1 polyether carbonate polyol based on AO polymer 3 and subsequent addition of carbon dioxide and 100% by weight of propylene oxide, functionality of 2.8, OH number of 55 mg KOH/g, CO ₂ content of 14% by weight. -%, produced by DMC catalysis

A2.1-1 Water

A3-1 silicone stabilizer (Tegostab BF2370)

A3-2 Amine Catalyst (Niax Al)

A3-3 Tin Catalyst (DABCO T9)

B-l Mixture of 2,4- and 2,6-tolylene diisocyanate in a weight ratio of

80:20

Production of polyurethane foams:

The flexible polyurethane foams described in Table 1 were produced in a discontinuous process.

Components A1-1 to A3-2 are weighed in according to the recipe (see Table 1) and stirred at room temperature for 20 seconds at a speed of 680 rpm. Then the necessary amount of component A3 -3 is added and the mixture is stirred at a speed of 680 rpm for 10 seconds with an agitator.

The previously weighed amount of component B1 is added and stirred with a stirrer at a speed of 750 rpm for 10 seconds. The mass is then added to a 1 m ³ mold. The walls of the 1 m ³ form were previously covered on the inside with polyethylene foil.

The height of the flexible polyurethane foam blocks was about 74-82 cm. The finished flexible polyurethane foam was stored in the post-reaction store for approx. 20-24 hours before it was sawn into test specimens for testing. Two specimens were analyzed to determine the mechanical properties of the flexible polyurethane foams. Table 1 shows the mean of the measurements in each case. Table 1: Formulations and mechanical properties

* Comparative Example Table 1 shows the mechanical properties of the polyurethane foams obtained from Examples 1 to 3. According to the process according to the invention, a polyether carbonate polyol A1.1 was used in each of Examples 1 and 2. The polyurethane foams from Examples 1 and 2 achieve tensile strength values of 110 kPa and 121 kPa, respectively, and values of 137% and 150%, respectively, for the elongation at break. In contrast, a polyether carbonate polyol A1.5-1 based on an alkylene oxide polymer with 100% by weight of propylene oxide was used in example 3 (comparison). The resulting polyurethane foam from Example 3 has a tensile strength of only 88 kPa and an elongation at break of 81%.

The flexible polyurethane foams produced according to the invention also have low emission values in the measurements according to LGA certification.

Claims

patent claims

1. Process for the production of polyurethane foams, the components A containing

A1 containing compounds with hydrogen atoms which are reactive towards isocyanates

Al.l polyether carbonate polyol,

A2 propellants and optionally A3 auxiliaries and additives and

2. The method according to claim 1, characterized in that component Al has the following composition:

Al.l 40 to 100 parts by weight polyether carbonate polyol with a hydroxyl number according to DIN 53240-1 (June 2013) of 20 mg KOH/g to 120 mg KOH/g,

A1.2 0 to 60 parts by weight of polyether polyol with a hydroxyl number in accordance with DIN 53240-1 (June

2013) from 20 mg KOH/g to 250 mg KOH/g and an ethylene oxide content of 0 to 60% by weight, with polyether polyol A1.2 being free of carbonate units,

A1.3 0 to 20 parts by weight of polyether polyol with a hydroxyl number in accordance with DIN 53240-1 (June

2013) from 20 mg KOH/g to 250 mg KOH/g, and an ethylene oxide content of > 60% by weight, with polyether polyol A1.3 being free of carbonate units,

A1.4 0 to 40 parts by weight polymer polyol, PHD polyol and/or PIPA polyol,

A1.5 0 to 40 parts by weight of a polyol which is not included in the definition of the components

Al.1 to Al.4, the parts by weight being stated in each case based on the sum of the parts by weight of the components Al.1+Al.2+Al.3+Al.4+Al.5=100 parts by weight.

3. The method according to claim 1 or 2, characterized in that the proportion of ethylene oxide units in the first alkylene oxide block of Al.l 1 to 25 wt .-%, preferably 5 to 22 wt .-% is.

4. The method according to any one of claims 1 to 3, characterized in that the first alkylene oxide block consists only of ethylene oxide and propylene oxide units.

5. The method according to any one of claims 1 to 4, characterized in that the alkylene oxide added on in the second block contains at least 90% by weight of propylene oxide.

6. The method according to claim 1, characterized in that the polyether carbonate polyol Al.I is obtained by a process comprising the steps

(i) addition of alkylene oxide containing 0.5 to 30% by weight of ethylene oxide to form a first alkylene oxide block onto a starter compound S1 having a molecular weight of 18 to 200 g/mol, preferably in the presence of a DMC catalyst, resulting in an alkylene oxide polymer,

(ii) Addition of carbon dioxide and alkylene oxide, preferably in the presence of a DMC catalyst, onto the alkylene oxide polymer resulting from (i) to form a polyether carbonate polyol.

7. The method according to claim 6, characterized in that the alkylene oxide polymer resulting from step (i) has a molecular weight of 250 to 2000 g/mol, preferably 400 to 1200 g/mol.

8. The method according to any one of claims 1 to 7, characterized in that the starter compound S1 is one or more compounds selected from the group consisting of ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1, 4-butanediol, 1,5-pentanediol, 2-methylpropane-1,3-diol, neopentyl glycol, 1,6-hexanediol, 1,8-octanediol, diethylene glycol, dipropylene glycol, glycerol, trimethylolpropane, pentaerythritol and sorbitol.

9. The method according to any one of claims 1 to 8, characterized in that the method is carried out at an isocyanate index of 75-120.

10. polyurethane foam, preferably flexible polyurethane foam, produced by a method according to any one of claims 1 to 9.

11. Use of a polyurethane foam according to claim 10 for the production of furniture upholstery, textile inserts, mattresses, automobile seats, headrests, armrests, sponges, headliners, door panels, seat covers or components.

12. A process for preparing polyethercarbonate polyols, comprising the steps

(i) Addition of alkylene oxide containing from 0.5 to 30% by weight of ethylene oxide to form a first alkylene oxide block onto a starter compound S1 with a molecular weight of 18 to 200 g/mol, preferably in the presence of a DMC catalyst, resulting in an alkylene oxide polymer,

13. The method according to claim 12, characterized in that in step (ii)

(a) a portion of the alkylene oxide polymer resulting from (i) and/or a suspending agent which has no H-functional groups is initially charged in a reactor, optionally together with DMC catalyst,

(ß) optionally, to activate a DMC catalyst, a portion (based on the total amount of alkylene oxide used in the activation and copolymerization) of alkylene oxide is added to the mixture resulting from step (a), this addition of a portion of alkylene oxide optionally can take place in the presence of CO2, and in which case the temperature peak (“hotspot”) and/or a drop in pressure in the reactor that occurs as a result of the following exothermic chemical reaction is then awaited in each case, and in which step (ß) for activation can also take place several times,

(g) the alkylene oxide polymer resulting from (i), alkylene oxide and optionally a suspending agent which does not have H-functional groups and carbon dioxide are metered into the reactor during the reaction.

14. The method according to claim 12 or 13, characterized in that the alkylene oxide polymer resulting from step (i) has a molecular weight of 250 to 2000 g/mol, preferably 400 to 1200 g/mol.

15. Polyether carbonate polyol based on a starter compound S 1 with a molecular weight of 18 to 200 g / mol, on which a first, inner alkylene oxide block containing 0.5 to 30 wt .-% ethylene oxide units, based on the total mass of the alkylene oxide used in the first block, and a second, outer block of carbon dioxide and alkylene oxide is attached.