Process for at least partially removing aldehydes from a composition containing at least one compound having at least one alkylene oxide unit

Abstract

The invention relates to a process for at least partially removing aldehydes from a composition, the process comprising the following steps: a) bringing the composition into contact with at least one cation exchanger and / or an acid at a temperature of 20.0°C to 250.0°C; b) at least partial separation of the aldehydes from the composition and optional treatment of the separated aldehydes, which treatment is selected from the group consisting of condensation, absorption, adsorption, chemical bonding, chemical reaction, oxidation and pyrolysis; a composition having a reduced aldehyde content being obtained; the composition to be treated in step a) containing at least one compound, which has at least one alkylene oxide unit in its chemical structure and a molecular weight of 200 g / mol or more, and 3.5 wt.% or less of alcohols having 1 to 6 carbon atoms, based on the total weight of the composition. The invention also relates to a composition containing at least one compound which has at least one alkylene oxide unit in its chemical structure and a molecular weight of 200 g / mol or more, the total aldehyde content being 1000 ppm or less.

Description

[0001] Process for the at least partial removal of aldehydes from a composition containing at least one compound having at least one alkylene oxide unit

[0002] The invention relates to a process for the at least partial removal of aldehydes from a composition, and to the resulting chemical products with a low aldehyde content. The chemical products are brought into contact with at least one cation exchanger and / or an acid, and the aldehydes are subsequently removed from the product by means of a separation process. This allows the production of products with an aldehyde content reduced by at least 10% of its initial value.

[0003] Background of the invention

[0004] Aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, and butyraldehyde are undesirable byproducts, for example, in the conversion of alkylene oxides (such as ethylene oxide, propylene oxide, butylene oxide) to alkylene oxide adducts such as polyalkylene glycols and nonionic surfactants. These byproducts can only be reduced to a certain extent by adjusting process parameters such as temperature. Due to regulatory requirements or the use of the above-mentioned products in critical applications (e.g., hygiene products), a reduction in the aldehyde content may be necessary.

[0005] State of the art

[0006] EP 0 638 538 A1 describes the removal of formaldehyde from an aqueous acetic acid solution by adding methanesulfonic acid (and optionally a polyol). According to US Pat. No. 5,440,058, formaldehyde is converted into the sodium salt of hydroxymethanesulfonic acid by adding NaHSO . EP 0 309 915 A1 describes the removal of formaldehyde from an aqueous butynediol solution by adding an "acidic agent," such as methanesulfonic acid or a cation exchanger, and methanol, producing dimethyl formal, which is distilled off. According to US Pat. No. 6,187,973, an aqueous ethylene glycol solution containing aldehydes such as formaldehyde, acetaldehyde, and the like is contacted with a solid, bisulfite-treated, strongly basic anion exchange resin, and a solution with a reduced aldehyde content is separated.

[0007] CA 1330350 discloses a process for purifying ethylene glycol using a basic ion exchange resin containing bisulfite or hydroxyl groups. The anion exchange resin adsorbs aldehyde impurities from the ethylene glycol.

[0008] DE 1668052 describes processes for the purification of glycols to remove substances that cause discoloration by means of cation exchangers, whereby essentially formaldehyde-free glycols are already used in the purification process.

[0009] The aldehyde removal in the above-mentioned patents is limited to low molecular weight chemical compounds.

[0010] WO 2019 / 097407 discloses polymeric resins functionalized with primary amines for the removal of aldehydes. The resins are capable of removing aliphatic and aromatic aldehydes from a wide variety of feed streams. The resins form covalent imine bonds with aldehyde impurities. However, the exclusive use of a basic ion exchanger, as claimed in WO 2019 / 0974707, does not achieve a significant reduction of aldehydes in alkoxylates.

[0011] EP 3 228 649 A1 describes a process for the treatment of alkali-catalyzed alkoxylation products using sulfonic acid ion exchangers, comprising providing a mixture containing the alkali-catalyzed alkoxylation product to be treated, alcohol having 1 to 4 carbon atoms and water, treating this mixture with a sulfonic acid cation exchanger at >40 °C, and separating the alkoxylation product from the mixture thus treated.

[0012] Technical task

[0013] The technical object of the present invention was therefore to provide a process with which a significant reduction of aldehydes in alkoxylates can be achieved, especially of alkoxylates with a higher molecular weight. Furthermore, a preferred object was to remove other undesirable impurities from alkoxylates in addition to aldehydes. In particular, the object of the present invention was to reduce or avoid the use of solvents, such as alcohols, in processes for purifying alkoxylates or in processes for removing aldehydes from alkoxylates.

[0014] Description of the invention

[0015] The present invention provides a process for the at least partial removal of aldehydes from a composition, the process comprising the following steps: a) contacting the composition with at least one cation exchanger and / or an acid at a temperature of 20.0 °C to 250.0 °C; b) at least partial separation of the aldehydes from the composition and optionally treatment of the separated aldehydes selected from the group consisting of condensation, absorption, adsorption, chemical bonding, chemical conversion, oxidation and pyrolysis; whereby a composition with a reduced content of aldehydes is obtained; wherein the composition to be treated in step a) contains at least one compound having at least one alkylene oxide unit in its chemical structure and a molecular weight of 200 g / mol or more, and

[0016] 3.5 wt.% or less of alcohols having 1 to 6 carbon atoms, based on the total weight of the composition. In a preferred process, the composition to be treated in step a) (which contains at least one compound having at least one alkylene oxide unit in its chemical structure and a molecular weight of 200 g / mol or more) contains 3.0 wt.% or less, more preferably 2.5 wt.% or less, even more preferably 2.0 wt.% or less, particularly preferably 1.5 wt.% or less, particularly preferably 1.0 wt.% or less, very particularly preferably 0.5 wt.% or less, most preferably 0.1 wt.% or less of alcohols having 1 to 6 carbon atoms, based on the total weight of the composition. More preferably, the composition to be treated in step a) contains no (i.e. 0.0 wt.%) alcohol having 1 to 6 carbon atoms.

[0017] In a further preferred process, the composition to be treated in step a) (which contains at least one compound which has at least one alkylene oxide unit in its chemical structure and a molecular weight of 200 g / mol or more) contains 3.5% by weight or less, preferably 3.0% by weight or less, more preferably 2.5% by weight or less, even more preferably 2.0% by weight or less, particularly preferably 1.5% by weight or less, particularly preferably 1.0% by weight or less of a solvent having 1 to 6 carbon atoms, based on the total weight of the composition. An alcohol having 1 to 6 carbon atoms represents a solvent having 1 to 6 carbon atoms.

[0018] In an alternative preferred process, the composition to be treated in step a) (which contains at least one compound which has at least one alkylene oxide unit in its chemical structure and a molecular weight of 200 g / mol or more) contains 3.5% by weight or less, preferably 3.0% by weight or less, more preferably 2.5% by weight or less, even more preferably 2.5% by weight or less, even more preferably 2.0% by weight or less, even more preferably 1.5% by weight or less, particularly preferably 1.5% by weight or less, and particularly preferably 1.0% by weight or less of a solvent selected from the group consisting of aliphatic ethers, cyclic ethers, hydrocarbons, ketones, alcohols having 1 to 6 carbon atoms, based on the total weight of the composition.

[0019] In a preferred process, the aldehydes are selected from the group of aldehydes with a molecular weight of 200 g / mol or less. More preferably, the aldehydes are selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, and butyraldehyde. This applies to the aldehydes to be removed prior to carrying out the process, to the aldehydes separated by the process, and to the reduced aldehyde content, if present.

[0020] The invention thus provides a process with which aldehydes can be removed not only from chemical products or compositions containing low-molecular-weight glycols, but also from those containing glycols and (poly)alkylene oxide compounds with higher molecular weight. Furthermore, within the scope of the invention, the inventor has discovered that further impurities such as dioxane and metal ions can be removed from such compositions. Furthermore, the inventor of the present invention has found that, in contrast to prior art processes, solvents such as alcohols, in particular alcohols with 1 to 6 carbon atoms, do not need to be added to the composition to be treated in order to achieve the desired purification. The process according to the present invention is advantageous because corresponding alcohols are not provided and do not have to be separated and recycled.This reduces the complexity and costs of the process. The same preferably applies to the solvents mentioned above.

[0021] The composition to be purified or the purified composition with a reduced aldehyde content, wherein the composition to be purified or the purified composition each contains at least one compound having at least one alkylene oxide unit in its chemical structure and a molecular weight of 200 g / mol or more, is understood to be a liquid composition or a liquid, preferably a solution or an emulsion. The liquid aggregate state of the composition is present at least under the conditions of the process according to the invention, in particular at the temperature applied during the process.

[0022] It has surprisingly been found that by treating compositions or chemical products with at least one cation exchanger and / or an acid at temperatures of 20°C to 250°C, preferably at temperatures of 40°C to 140°C (step a) and a subsequent separation process to remove aldehydes (step b), products are obtained with an aldehyde content reduced by at least 10% of the starting value. In a particularly preferred process, step a) is carried out at a temperature of 40°C to 140°C, more preferably at a temperature of 60°C to 120°C, even more preferably at a temperature of 80°C to 120°C, and especially preferably at a temperature of 85°C to 120°C.

[0023] The process according to the invention can be operated continuously or discontinuously.

[0024] In a further preferred process, the cation exchanger used in step a) is an acidic cation exchanger containing acid groups selected from the group consisting of -SO3H, -COOH, and -OP(OH)s. Thus, the cation exchangers preferably have sulfonic acid groups (-SO3H), carboxyl groups (-COOH), or orthophosphoric acid groups (-OP(OH)s) as functional groups in the uncharged form.

[0025] The matrix of the ion exchange resins can be obtained, for example, by condensation (phenol-formaldehyde matrix) or by polymerization (polystyrene matrix, matrix of copolymers of styrene with divinylbenzene, polyacrylic matrix, matrix of copolymers of acrylates, methacrylates or acrylonitrile with divinylbenzene).

[0026] The ion exchange resins used according to the invention can be in various forms, such as solid grains and particles (pellets, beads), membranes, films, fibers, and fabrics. Solid grains and particles (pellets, beads) are preferred as the ion exchange resins.

[0027] In continuous operation, the ion exchangers can be installed in columns or containers, for example. The columns or containers can have nozzle trays or drainage systems for the inlet and / or outlet of the treated chemical product. The ion exchanger can be operated continuously in various configurations, for example, as a countercurrent, cocurrent, layered-bed, multi-chamber, double-flow, sandwich, or mixed-bed exchanger.

[0028] In discontinuous operation, the ion exchangers can, for example, be present in free form in the composition, i.e. in the chemical product, or in perforated containers that come into contact with the composition.

[0029] In a further preferred process, the acid used in step a) is selected from the group consisting of sulfuric acid, phosphoric acid, phosphonic acid, phosphinic acid, hydrochloric acid, methanesulfonic acid, toluenesulfonic acid and alkylbenzenesulfonic acid, preferably methanesulfonic acid. The concentration of the acids used is preferably 10 wt.% or less, more preferably 5.0 wt.% or less, particularly preferably 2.0 wt.% or less and very particularly preferably 1.0 wt.% or less. In the process in which an acid is used in step a), the compound which has at least one alkylene oxide unit in its chemical structure and a molecular weight of 200 g / mol or more is particularly preferably a compound with a carbon backbone.

[0030] As explained above, according to the invention, in step b), a partial separation of the aldehydes from the composition takes place, preferably followed by a treatment of the separated aldehydes selected from the group consisting of condensation, absorption, adsorption, chemical bonding, chemical conversion, oxidation, and pyrolysis. The preferred step of treating the separated aldehydes selected from the group consisting of condensation, absorption, adsorption, chemical bonding, chemical conversion, oxidation, and pyrolysis following step b) can be referred to as step c).

[0031] In a further preferred embodiment, step b) is carried out by a thermal separation process selected from the group consisting of distillation processes, rectification processes, stripping processes, and flash evaporation processes. The above-mentioned thermal separation processes can also be combined. Furthermore, solvents such as water or entraining agents can be added to the composition to be purified to increase the separation efficiency.

[0032] In process step b), i.e. the thermal separation process, which is selected from the group consisting of distillation processes, rectification processes, stripping processes and flash evaporation processes, the aldehydes are removed from the composition (i.e. from the product (stream)) via the gas phase. In a particularly preferred embodiment, the destination, rectification or stripping process is carried out under vacuum. In the stripping process, the stripping gas used can be, for example, steam, nitrogen, carbon dioxide, air or argon. The substances present in the gas stream, such as aldehydes, can be at least partially removed from the gas phase by conventional processes for off-gas purification or exhaust air purification. It goes without saying that biological off-gas purification is also included.For example, the substances contained in the gas phase, such as aldehydes, can be condensed and thus collected or absorbed using an absorption medium, such as a scrubbing solution. If the absorption capacity of the absorption medium, such as water, is insufficient, absorption can be supplemented by chemical conversion with chemical auxiliaries (chemisorption). Furthermore, the substances contained in the gas stream can, for example, be adsorbed using an adsorption medium, such as activated carbon, or chemically bound or chemically converted using an ion exchanger. Chemical conversion generally includes catalytic and non-catalytic chemical processes. In the non-catalytic chemical process, aldehyde adducts can be formed using chemical auxiliaries, such as bisulfites, to at least partially remove the aldehydes.Furthermore, the substances can be decomposed in the gas phase by oxidation or pyrolysis, which includes the post-combustion process. It goes without saying that the above-mentioned processes—condensation, absorption, adsorption, chemical bonding, chemical conversion, oxidation, and pyrolysis—can also be combined.

[0033] Examples of thermal separation devices that can also be operated under vacuum include distillation columns, rectification columns, evaporators such as forced and natural circulation evaporators, horizontal evaporators, rotary evaporators, falling-film evaporators, thin-film evaporators, short-path evaporators, degassers, or spray dryers, with the evaporator unit preferably being followed by an exhaust gas purification unit or exhaust air purification unit. Venturi scrubbers, spray scrubbers, jet scrubbers, or vortex scrubbers can be used as absorbers. Fixed-bed, rotor, fluidized-bed, and moving-bed adsorbers can be used as adsorbers. To separate gaseous substances, such as aldehydes, as liquids, cooling units for condensation can be connected downstream of the thermal separation devices. Afterburners can also be connected downstream of the thermal separation devices.In the case of biological exhaust gas purification, bioscrubbers, biofilters, and biotrickling bed reactors can be used, among others.

[0034] In an alternative preferred embodiment of the process, step b) is carried out by contacting with an ion exchanger having amino or bisulfite functional groups, wherein step b) is preferably carried out at a temperature of 20 °C to 250 °C. The aldehydes are bound to the ion exchanger and removed from the composition (i.e., from the product stream).

[0035] Amino-functional ion exchangers can, for example, be based on a branched polystyrene matrix containing functional amino groups. The amino-functional ion exchangers are brought into contact with the chemical product (stream) to bind the aldehydes contained therein to the amino group and thus remove them from the product (stream). For example, primary amino groups of the resins can covalently bind the aldehydes to form an imine compound.

[0036] Bisulfite-functional ion exchangers can be produced, for example, by treating a strongly basic ion exchange resin containing hydroxyl groups with a bisulfite solution. This treatment converts the basic ion exchanger into the bisulfite form containing (resin-HSO3') groups. The production of the bisulfite form is illustrated below using the example of treating a strongly basic ion exchange resin with a sodium bisulfite solution:

[0037] Resin-OH' + Na + HSO3' ​​(solution) -> resin-HSOs' + Na + OH' (solution)

[0038] The (resin-HSO3') groups can bind the aldehydes contained in the chemical product in contact and thus remove them from the product (stream), whereby the following reaction mechanism can be expected using the example of the elimination of formaldehyde:

[0039] Resin-HSO3- + HOHO -> Resin-HOCH2SO3-

[0040] In a further preferred process, the content of compounds having at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more in the composition used is at least 10 wt.% based on the total weight of the composition, preferably at least 20 wt.%, preferably at least 50 wt.%, more preferably at least 80 wt.%, even more preferably at least 90.0 wt.%, even more preferably at least 95.0 wt.%, even more preferably at least 98.0 wt.%, even more preferably at least 99.0 wt.%, and most preferably at least 99.5 wt.%. These contents preferably also apply to the composition obtained after step b), which has a reduced content of aldehydes.

[0041] The process according to the invention enables the removal of aldehydes not only in aqueous but also from concentrated compositions or chemical products. Therefore, the water content in the composition used is preferably 90 wt.% or less based on the total weight of the composition, more preferably 70 wt.% or less, even more preferably 50 wt.% or less, more preferably 40 wt.% or less, more preferably 30 wt.% or less, more preferably 20 wt.% or less, even more preferably 10.0 wt.% or less, even more preferably 5.0 wt.% or less, even more preferably 2.0 wt.% or less, even more preferably 1.0 wt.% or less, and most preferably 0.5 wt.% or less. These water contents preferably also apply to the composition obtained after step b), which has a reduced aldehyde content.

[0042] In a further preferred embodiment of the invention, the aldehydes to be removed from the compositions have at least one aldehyde group in their structure. The aldehydes may have further functional groups and may also contain heteroatoms in their structure. In a preferred process, the aldehydes are selected from the group consisting of aldehydes with a molecular weight of 200 g / mol or less. Further preferably, the aldehydes are selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, and butyraldehyde.

[0043] The process according to the invention achieves excellent purification, particularly with regard to aldehydes. In a preferred process, after step b), a composition is obtained in which the total aldehyde content is reduced by at least 10% of the starting value, more preferably by at least 30%, preferably by at least 50%, more preferably by at least 80%, even more preferably by at least 90%, even more preferably by at least 95%, even more preferably by at least 98%, and even more preferably by at least 99%. In a preferred process, the total aldehyde content is defined as the total content of aldehydes having a molecular weight of 200 g / mol or less. In a further preferred process, the total aldehyde content is defined as the total content of aldehydes selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, and butyraldehyde.In a particularly preferred process, a composition is obtained after step b) in which the total content of aldehydes is reduced to 1000 ppm or less, more preferably to 900 ppm or less, preferably to 800 ppm or less, more preferably to 500 ppm or less, even more preferably to 400 ppm or less, even more preferably to 300 ppm or less, even more preferably to 200 ppm or less, even more preferably to 150 ppm or less, even more preferably to 100 ppm or less, even more preferably to 50 ppm or less, and most preferably to 10 ppm or less. In a particularly preferred embodiment, these residual aldehyde contents refer to a composition whose content of compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more is at least 10 wt.-% based on the total weight of the composition, particularly preferably at least 50 wt.%. In a preferred process, the total aldehyde content is defined as the total content of aldehydes having a molecular weight of 200 g / mol or less. In a further preferred process, the total aldehyde content is defined as the total content of aldehydes selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, and butyraldehyde. The term "ppm" refers to the total aldehyde content in mg per 1 kg of the composition.

[0044] In a further very particularly preferred process, a composition is obtained after step b) whose content of compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more is at least 10 wt.% based on the total weight of the composition, particularly preferably at least 50 wt.-%, and in which the total content of aldehydes is reduced to 1000 ppm or less, more preferably to 900 ppm or less, preferably to 800 ppm or less, more preferably to 500 ppm or less, even more preferably to 400 ppm or less, even more preferably to 300 ppm or less, even more preferably to 200 ppm or less, even more preferably to 150 ppm or less, even more preferably to 100 ppm or less, even more preferably to 50 ppm or less, and most preferably to 10 ppm or less, wherein the total content of aldehydes is defined as the total content of aldehydes which have a molecular weight of 200 g / mol or less, wherein the total content of aldehydes is further preferably defined as the total content of aldehydes selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde and butyraldehyde.The term “ppm” refers to the total content of aldehydes in mg per 1 kg of the composition.

[0045] In addition to the removal of aldehydes, it has surprisingly been found that dioxane can also be removed using the process according to the invention. With regard to dioxane, the following description refers primarily to 1,4-dioxane. However, other dioxane isomers are also contemplated. Therefore, the dioxane comprises one or more substances selected from the group consisting of 1,2-dioxane, 1,3-dioxane, and 1,4-dioxane, preferably 1,4-dioxane.Therefore, in a further preferred process, step b) is carried out by a thermal separation process selected from the group consisting of distillation processes, rectification processes, stripping processes and flash evaporation processes, wherein after step b) a composition is obtained in which the dioxane content is reduced to 1000 ppm or less, more preferably to 900 ppm or less, preferably to 800 ppm or less, more preferably to 500 ppm or less, even more preferably to 400 ppm or less, even more preferably to 300 ppm or less, even more preferably to 200 ppm or less, even more preferably to 150 ppm or less, even more preferably to 100 ppm or less, even more preferably to 50 ppm or less, and most preferably to 10 ppm or less.In a particularly preferred embodiment, these residual dioxane contents mentioned here refer to a composition whose content of compounds having at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more is at least 10 wt.%, based on the total weight of the composition, particularly preferably at least 50 wt.%. The term "ppm" refers to the amount of dioxane in mg per 1 kg of the composition. In addition to the separation of aldehydes, the process according to the invention can also remove the alkoxylation catalyst, such as NaOH or KOH, or metal cyanide complex catalysts as disclosed in US 5,158,922 or US 2003 / 0119663, using a cation exchanger in step a).Therefore, in a further preferred process, in step a) the composition is brought into contact with at least one cation exchanger, wherein after step b) a composition is obtained in which the content of metal ions is reduced to 1000 ppm or less, more preferably to 900 ppm or less, preferably to 800 ppm or less, more preferably to 500 ppm or less, even more preferably to 400 ppm or less, even more preferably to 300 ppm or less, even more preferably to 200 ppm or less, even more preferably to 150 ppm or less, even more preferably to 100 ppm or less, even more preferably to 50 ppm or less, and most preferably to 10 ppm or less.In a particularly preferred embodiment, these residual contents of metal ions mentioned here refer to a composition whose content of compounds having at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more is at least 10 wt.% based on the total weight of the composition, particularly preferably at least 50 wt.%. In a preferred embodiment, the metal ions are selected from the group consisting of Na(I), K(I), Zn(II), Fe(II), Fe(III), Co(II), Co(III), Ni(II), Mn(II), Mn(III), Ir(III), Rh(III), Ru(II), V(IV), V(V), Co(II), Sn(II), Pb(II), Mo(IV), Mo(VI), Al(III), V(IV), V(V), Sr(II), W(IV), W(VI), Cu(II), Cr(II) and Cr(III). The term “ppm” refers to the amount of metal ions in mg per 1 kg of the composition.

[0046] Compounds that have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more

[0047] In another particularly preferred process, the composition or compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more are obtained from a polymerization of alkylene oxides or an alkoxylation process. In the present application, the molecular weight stated for "compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more" always refers to the number-average molecular weight. The terms "number-average molecular weight" and "number-average molecular weight" are used synonymously here. Furthermore, the terms "molecular weight" and "molar mass" are used synonymously.

[0048] The number-average molecular weight can be calculated, for example, from the quantities used in the synthesis. For example, if a fatty alcohol with 5 ethylene oxide (EO) units is to be synthesized, a corresponding mass ratio of fatty alcohol to ethylene oxide (EO) is weighed during the synthesis of this alkoxylate, with one EO unit corresponding to 44.05 g / mol. The number-average molecular weight of the ethoxylated fatty alcohol is calculated by adding the molecular weight of the fatty alcohol (e.g., 1-octadecanol: 270.5 g / mol) and the 5 ethylene oxide units (5*44.05 g / mol).

[0049] The number-average molecular weights can be determined by cryoscopy, ebullioscopy, vapor pressure osmometry (for molar masses up to approximately 50,000 g / mol), osmometry (for molar masses up to approximately 10,000 g / mol), or NMR spectroscopy. Furthermore, the number-average molecular weight can be determined from the molar mass distribution using gel permeation chromatography (GPC) and mass spectrometry (MALDI-TOF).

[0050] Furthermore, the number-average molecular weight can be determined according to the OECD guidelines (Guidelines for the Testing of Chemicals, Section 1) using test no. 118 (Determination of the Number-Average Molecular Weight and the Molecular Weight Distribution of Polymers using Gel Permeation Chromatography).

[0051] Compounds having the following formula (I) can be used as alkylene oxides where R 2 and R 3independently of one another represent hydrogen or a hydrocarbon radical; where the hydrocarbon radical can be a cycloaliphatic hydrocarbon radical, preferably a linear or branched hydrocarbon radical, in particular a hydrocarbon radical having 1 to 20, preferably 1 to 6, carbon atoms, particularly preferably a methyl, ethyl or phenyl radical. The radicals R 2 and R 3 can also be part of a cyclic group, R 2 and R 3 then form a divalent residue. The hydrocarbon residues R 2 and R 3 can in turn carry functional groups such as halogens, hydroxyl groups, and glycydyloxypropyl groups. Such alkylene oxides include epichlorohydrin, 2,3-epoxy-1-propanol, as well as polyfunctional epoxy compounds such as 1,2-ethyl, 1,4-butyl, and 1,6-hexyl diglycidyl ether. Preferably, at least one of the two radicals R 2 or R 3a hydrogen. Particularly preferred alkylene oxides are those selected from the group consisting of ethylene oxide, propylene oxide, 1,2- or 2,3-butylene oxide, isobutylene oxide, 1,2-dodecene oxide, cyclohexene oxide, vinylcyclohexene oxide, and styrene oxide.

[0052] Glycidyl compounds, such as glycidyl ethers or glycidyl esters, whose at least one glycidyloxypropyl group is bonded to a linear or branched alkyl radical of 1 to 24 carbon atoms, an aromatic or cycloaliphatic radical via a linkage to the ether or ester function, can also be used as alkylene oxides. This class of compounds includes, for example, allyl, butyl, 2-ethylhexyl, cyclohexyl, benzyl, C12 / C14 fatty alcohol, phenyl, p-tert-butylphenyl, and o-cresyl glycidyl ethers. Preferred glycidyl esters include, for example, glycidyl methacrylate, glycidyl acrylate, and neodecanoic acid glycidyl ester.

[0053] In a further particularly preferred process, the compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more have at least one (poly)alkylene oxide group with at least 1, preferably with at least 2, preferably with at least 3, more preferably with at least 4 and even more preferably with at least 5 alkylene oxide units, even more preferably with at least 6, even more preferably with at least 8, even more preferably with at least 10, even more preferably with at least 12, even more preferably with at least 15, even more preferably with at least 50 and most preferably with at least 100 alkylene oxide units. The upper limit of the alkylene oxide units is not particularly limited. In preferred embodiments, the number of alkylene oxide units is 500 or less, more preferably 200 or less and even more preferably 150 or less.The alkylene oxide units are preferably selected from the group consisting of ethylene oxide, propylene oxide and butylene oxide, particularly preferably ethylene oxide and / or propylene oxide.

[0054] In a further particularly preferred process, the compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more have at least one (poly)alkylene oxide group of the formula -(C2H4-O)i-(C3H6-O) m -(C4H8-O)n- or -(C2H4-O)i-(C3H6-O) m- (C4H8-O)nH, where I, m and n are each independently a number of 0 or more, and where the sum of I, m and n is a number of 1 or more, preferably the sum of I, m and n is a number of 2 or more, preferably the sum of I, m and n is a number of 3 or more, more preferably 4 or more, even more preferably 5 or more, even more preferably 6 or more, even more preferably 8 or more, even more preferably 10 or more, even more preferably 12 or more, particularly preferably 15 or more, especially preferably 50 or more, and most preferably 100 or more. The upper limit of the alkylene oxide units is not particularly limited. In further embodiments, it is preferred that the sum of I, m and n is a number from 1 to 500, more preferably the sum of I, m and n is a number from 1 to 200 and even more preferably the sum of I, m and n is a number from 1 to 150.In a further particularly preferred embodiment, the sum of I, m and n is a number from 2 to 500, preferably the sum of I, m and n is a number from 2 to 200 and particularly preferably the sum of I, m and n is a number from 2 to 150.

[0055] In a further particularly preferred process, the compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more have at least one polyoxyalkylene group of the formula -(CXH2X-O)Y- or -(C x H2x-O) y-H, where x is a number 2, 3 or 4, and y is a number of 1 or more, preferably y is a number of 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 8 or more, 10 or more, 12 or more, 15 or more, 50 or more, 100 or more. The upper limit of the alkylene oxide units is not particularly limited. In further embodiments, it is preferred that y is a number from 1 to 500, more preferably y is a number from 1 to 200, and even more preferably y is a number from 1 to 150. In another particularly preferred embodiment, y is a number from 2 to 500, preferably y is a number from 2 to 200, and particularly preferably y is a number from 2 to 150.

[0056] In preferred embodiments, the molecular weight of the compounds having at least one alkylene oxide unit in their chemical structure is 250 g / mol or more, preferably 300 g / mol or more, more preferably 400 g / mol or more, even more preferably 500 g / mol or more, particularly preferably 1,000 g / mol or more, and particularly preferably 2,000 g / mol or more. The upper limit of the molecular weight of the compounds having at least one alkylene oxide unit in their chemical structure is not particularly limited. In preferred embodiments, the molecular weight of the compounds having at least one alkylene oxide unit in their chemical structure is 100,000 g / mol or less, preferably 50,000 g / mol or less, more preferably 25,000 g / mol or less, even more preferably 20,000 g / mol or less, particularly preferably 15,000 or less and particularly preferably 12,000 g / mol or less.

[0057] In a further particularly preferred process, the alkylene oxide units of the compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more are selected from the group consisting of ethylene oxide, propylene oxide, and butylene oxide. In a further preferred embodiment of the process, the compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more are (poly)alkylene oxide adducts with at least one further radical selected from the group consisting of carboxylic acid radicals, carboxylic acid ester radicals, carboxamide radicals, phenol radicals, and alcohol radicals. The alkylene oxide units are preferably selected from the group consisting of ethylene oxide, propylene oxide, and butylene oxide, particularly preferably ethylene oxide and / or propylene oxide.

[0058] (Poly)-alkylene oxide adducts within the meaning of this description are reaction products of alkoxylatable starting materials such as carboxylic acids such as ethylhexanoic acid, benzoic acid or fatty acids such as caprylic acid, capric acid, lauric acid, coconut fatty acid, palmitic acid, stearic acid, oleic acid, ricinoleic acid or with several carboxyl groups such as citric acid, agaric acid and propane-1,2,3-tricarboxylic acid, trimellitic acid, trimesic acid, pyromellitic acid and mellitic acid and mixtures thereof, carboxylic acid esters such as triglycerides such as castor oil, rapeseed oil, soybean oil, sunflower oil, coconut fat or diglycerides such as glycerol dioleate or monoglycerides such as glycerol monooleate or sorbitan esters such as sorbitan monolaurate, sorbitan monooleates, sorbitan trioleate, sorbitan monostearate, sorbitan sesquiisostearate or polyglycerol- fatty acid esters such as polyglycerol cocoate, polyglycerol riciolate, polyglycerol oleate or fatty acid esters such as methyl oleate, carboxylic acid amides such as fatty acid amides such as coconut fatty acid amide,Coconut fatty acid monoethanolamide, coke fatty acid diethanolamide, oleic acid amide, phenols such as alkylphenols, tristyrylphenol, monohydric alcohols such as methanol, ethanol, propanol, butanol, ethylhexanol, methoxyethanol, methyl diglycol or fatty alcohols such as lauryl alcohol, stearyl alcohol, oleyl alcohol or oxo alcohols such as isotridecyl alcohol, linear or branched oxo alcohol Ci2-Ci5, or cyclic alcohols such as cyclohexanol or Guerbet alcohols such as butyloctanol, hexyldecanol and octyldecanol or polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, diethylene glycol, glycerin, polyglycerin, alkyl glycosides, sorbitol, mannitol, sorbitan, isosorbitol, trimethylolpropane, pentaerythritol, dipentaerythritol and mixtures thereof. The (poly)alkylene oxide adducts have at least one alkylene oxide unit, ie they have 1-500, preferably 1-200,more preferably 1-150 alkylene oxide units. The alkylene oxide units are preferably selected from the group consisting of ethylene oxide, propylene oxide, and butylene oxide, particularly preferably ethylene oxide and / or propylene oxide. The described (poly)alkylene oxide adducts can be composed of identical or different alkylene oxides, for example, of block-like or randomly arranged ethylene oxide and propylene oxide, so that the present application also encompasses such "mixed" alkylene oxide adducts.

[0059] In an alternative preferred embodiment of the process, the compounds having at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more are selected from the group consisting of polyglycols, polyalkylene glycols, block copolymers, carboxylic acid alkoxylates, carboxylic acid polyglycol esters, alkoxylated carboxylic acid esters, alkoxylated carboxamides, alkoxylated phenols, and alcohol alkoxylates. The alkylene oxide units are preferably selected from the group consisting of ethylene oxide, propylene oxide, and butylene oxide, particularly preferably ethylene oxide and / or propylene oxide.

[0060] Compounds that have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more are preferably derived from the group of C2-C4 alkylene oxides, preferably C2-C3 alkylene oxides. The alkylene oxide units are particularly preferably derived from ethylene oxide or propylene oxide or a mixture thereof. In a particular embodiment, the compounds that have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more are polyglycols having the formula H-[O-C2H4] P -[O-C3H6]q-[O-C4H8] r-OH, where p, q and r are each independently a number of 0 or more, and the sum of p, q and r is a number of 5 or more, preferably the sum of p, q and r is a number of 6 or more, preferably 8 or more, more preferably 10 or more, even more preferably 12 or more, particularly preferably 15 or more, especially preferably 50 or more, and most preferably 100 or more. The upper limit of the alkylene oxide units is not particularly limited. In further embodiments, it is preferred that the sum of p, q and r is a number from 5 to 500, more preferably the sum of p, q and r is a number from 5 to 200, and even more preferably the sum of p, q and r is a number from 5 to 150.In a further particularly preferred embodiment, the sum of p, q and r is a number from 10 to 500, preferably the sum of p, q and r is a number from 10 to 200 and particularly preferably the sum of p, q and r is a number from 10 to 150.

[0061] In a particular embodiment, the compounds that have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more are nonionic surfactants. Exemplary nonionic surfactants are selected from the group consisting of carboxylic acid alkoxylates, carboxylic acid polyglycol esters, alkoxylated carboxylic acid esters, alkoxylated carboxylic acid amides, alkoxylated phenols, block copolymers based on poly(alkylene oxides), and alcohol alkoxylates. It is understood that the above-mentioned nonionic surfactant classes may have additional functional groups or heteroatoms in their structure.

[0062] Examples of carboxylic acid alkoxylates and carboxylic acid polyglycol esters are based on 2-ethylhexanoic acid, benzoic acid, or fatty acid alkoxylates or fatty acid polyglycol esters based on caprylic acid, capric acid, lauric acid, coconut fatty acid, palmitic acid, stearic acid, oleic acid, ricinoleic acid, and mixtures thereof. Carboxylic acid alkoxylates and carboxylic acid polyglycol esters that may contain multiple ester groups in their structure include, for example, alkoxylates or polyglycol esters based on citric acid, agaric acid, and propane-1,2,3-tricarboxylic acid, trimellitic acid, trimesic acid, pyromellitic acid, and mellitic acid, and mixtures thereof.

[0063] Examples of alkoxylated carboxylic acid esters are alkoxylates based on triglycerides such as castor oil, rapeseed oil, soybean oil, sunflower oil, coconut fat, or diglycerides such as glycerol dioleate or monoglycerides such as glycerol monooleate, or sorbitan esters such as sorbitan monolaurate, sorbitan monooleate, sorbitan trioleate, sorbitan monostearate, sorbitan sesquiisostearate, or polyglycerol fatty acid esters such as polyglycerol cocoate, polyglycerol riciolate, polyglycerol oleate, or fatty acid esters such as methyl oleate, and mixtures thereof. The carboxylic acid esters used as starting compounds generally contain at least one hydroxyl and / or carboxyl group or are partially saponified prior to alkoxylation. Furthermore, conversion of the carboxylic acid esters to the corresponding alkoxylates is possible using an insertion alkoxylation process.

[0064] Examples of alkoxylated carboxylic acid amides are alkoxylates based on fatty acid amides such as coconut fatty acid amide, coconut fatty acid monoethanolamide, coke fatty acid diethanolamide, oleic acid amide and mixtures thereof.

[0065] Examples of alkoxylated phenols are alkoxylates based on alkylphenol derivatives such as n-propylphenols, isopropylphenols, butylphenols, amylphenols, hexylphenols, heptylphenols, octylphenols, nonylphenols, dodecylphenols, methylphenols (cresols), dimethylphenols (xylenols) and ethylphenols or tristyrylphenol and mixtures thereof.

[0066] Examples of block copolymers based on poly(alkylene oxides) are ethylene oxide-propylene oxide block polymers.

[0067] Examples of alcohol alkoxylates are alkoxylated monohydric alcohols based on methanol, ethanol, propanol, butanol, ethylhexanol, methoxyethanol, methyl diglycol or fatty alcohol alkoxylates based on lauryl alcohol, stearyl alcohol, oleyl alcohol or oxo alcohol alkoxylates based on isotridecyl alcohol, linear or branched oxo alcohol Ci2-Ci5, or alkoxylated cyclic alcohols such as cyclohexanol or Guerbet alcohol alkoxylates based on butyloctanol, hexyldecanol and octyldecanol or alkoxylated polyhydric alcohols, polyols based on ethylene glycol, propylene glycol, butanediol, diethylene glycol, glycerol, polyglycerol, alkyl glycosides, sorbitol, mannitol, sorbitan, isosorbitol trimethylolpropane, pentaerythritol, dipentaerythritol and their Mixtures.

[0068] The present invention further provides a composition comprising at least one compound having at least one alkylene oxide unit in its chemical structure and a molecular weight of 200 g / mol or more, wherein the total aldehyde content is 1000 ppm or less. In a preferred embodiment, the total aldehyde content is defined as the total content of aldehydes having a molecular weight of 200 g / mol or less. In a further preferred embodiment, the total aldehyde content is defined as the total content of aldehydes selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, and butyraldehyde. The term "ppm" refers to the total aldehyde content in mg per 1 kg of the composition.

[0069] As explained above, it has surprisingly been found that the treatment according to the invention of compositions comprising compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more gives products, ie corresponding compositions, having an aldehyde content which is reduced by at least 10% of the starting value.

[0070] Preferred embodiments or preferred features of the compositions comprising compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more, as well as the compounds themselves, are as already described above with regard to the process according to the invention.

[0071] In a preferred embodiment of the composition, the content of compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more is at least 10 wt.% based on the total weight of the composition, preferably at least 20 wt.%, preferably at least 50 wt.%, more preferably at least 80 wt.%, even more preferably at least 90.0 wt.%, even more preferably at least 95.0 wt.%, even more preferably at least 98.0 wt.%, even more preferably at least 99.0 wt.%, and most preferably at least 99.5 wt.%.

[0072] In a further preferred embodiment of the composition, the water content in the composition is preferably 90 wt% or less based on the total weight of the composition, more preferably 70 wt% or less, even more preferably 50 wt% or less, more preferably 40 wt% or less, even more preferably 30 wt% or less, more preferably 20 wt% or less, even more preferably 10.0 wt% or less, even more preferably 5.0 wt% or less, even more preferably 2.0 wt% or less, even more preferably 1.0 wt% or less, and most preferably 0.5 wt% or less.

[0073] In a further preferred embodiment of the composition, the total aldehyde content is 900 ppm or less, preferably 800 ppm or less, more preferably 500 ppm or less, even more preferably 400 ppm or less, even more preferably 300 ppm or less, even more preferably 200 ppm or less, even more preferably 150 ppm or less, even more preferably 100 ppm or less, even more preferably 50 ppm or less, and most preferably 10 ppm or less. In a particularly preferred embodiment, these residual aldehyde contents refer to a composition whose content of compounds having at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more is at least 10 wt.%, based on the total weight of the composition, particularly preferably at least 50 wt.%.As already mentioned above, in a preferred embodiment, the total aldehyde content is defined as the total content of aldehydes having a molecular weight of 200 g / mol or less. In a further preferred embodiment, the total aldehyde content is defined as the total content of aldehydes selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, and butyraldehyde.

[0074] In a further particularly preferred embodiment of the composition, the content of compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more is at least 10 wt.% based on the total weight of the composition, particularly preferably at least 50 wt.-%, wherein the total content of aldehydes is 1000 ppm or less, preferably 900 ppm or less, preferably 800 ppm or less, more preferably 500 ppm or less, even more preferably 400 ppm or less, even more preferably 300 ppm or less, even more preferably 200 ppm or less, even more preferably 150 ppm or less, even more preferably 100 ppm or less, even more preferably 50 ppm or less, and most preferably 10 ppm or less, wherein the total content of aldehydes is defined as the total content of aldehydes having a molecular weight of 200 g / mol or less, wherein the total content of aldehydes is further preferably defined as the total content of aldehydes selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde and butyraldehyde. The term “ppm” refers to the total content of aldehydes in mg per 1 kg of the composition.

[0075] As mentioned above, in addition to aldehydes, dioxane can also be removed. Therefore, in a further preferred embodiment of the composition, the dioxane content is 1000 ppm or less, more preferably 900 ppm or less, preferably 800 ppm or less, more preferably 500 ppm or less, even more preferably 400 ppm or less, even more preferably 300 ppm or less, even more preferably 200 ppm or less, even more preferably 150 ppm or less, even more preferably 100 ppm or less, even more preferably 50 ppm or less, and most preferably 10 ppm or less. The dioxane is preferably selected from the group consisting of 1,2-dioxane, 1,3-dioxane and 1,4-dioxane, particularly preferably 1,4-dioxane.In a particularly preferred embodiment, these residual dioxane contents mentioned here refer to a composition whose content of compounds having at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more is at least 10 wt.%, based on the total weight of the composition, particularly preferably at least 50 wt.%. The term "ppm" refers to the amount of dioxane in mg per 1 kg of the composition.

[0076] In addition to the separation of aldehydes, the alkoxylation catalyst, such as NaOH or KOH, can also be removed using a cation exchanger after step a) of the process. Therefore, in a further preferred embodiment of the composition, the metal ion content is 1000 ppm or less, more preferably 900 ppm or less, preferably 800 ppm or less, more preferably 500 ppm or less, even more preferably 400 ppm or less, even more preferably 300 ppm or less, even more preferably 200 ppm or less, even more preferably 150 ppm or less, even more preferably 100 ppm or less, even more preferably 50 ppm or less, and most preferably 10 ppm or less.In a particularly preferred embodiment, these residual contents of metal ions mentioned here refer to a composition whose content of compounds having at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more is at least 10 wt.% based on the total weight of the composition, particularly preferably at least 50 wt.%. In a preferred embodiment, the metal ions are selected from the group consisting of Na(I), K(I), Zn(II), Fe(II), Fe(III), Co(II), Co(III), Ni(II), Mn(II), Mn(III), Ir(III), Rh(III), Ru(II), V(IV), V(V), Co(II), Sn(II), Pb(II), Mo(IV), Mo(VI), Al(III), V(IV), V(V), Sr(II), W(IV), W(VI), Cu(II), Cr(II) and Cr(III). The term “ppm” refers to the amount of metal ions in mg per 1 kg of the composition.

[0077] The following Table A lists further preferred embodiments of the composition according to the invention, wherein the composition, which comprises at least one compound having at least one alkylene oxide unit in its chemical structure and a molecular weight of 200 g / mol or more, is defined in terms of the combination of the achieved or achievable contents of aldehyde and dioxane or of aldehyde, dioxane, and metal ions. The numerical values ​​are given in ppm and mean the stated numerical value in ppm or less. Preferably, the content of compounds having at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more is at least 10 wt.%, based on the total weight of the composition, particularly preferably at least 50 wt.%.The following Table A also lists preferred embodiments of the process with respect to the composition obtained after step b) with reduced levels of undesirable impurities (aldehyde and dioxane; aldehyde, dioxane, and metal ions) as indicated in the table. Table A: Preferred embodiments of the process and composition with respect to the impurities aldehydes, dioxane, and metal ions:.

[0078] In a further preferred embodiment of the composition, the compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more have at least one (poly)alkylene oxide group with at least 1, preferably with at least 2, preferably with at least 3, more preferably with at least 4 and even more preferably with at least 5 alkylene oxide units, even more preferably with at least 6, even more preferably with at least 8, even more preferably with at least 10, even more preferably with at least 12, even more preferably with at least 15, even more preferably with at least 50 and most preferably with at least 100 alkylene oxide units. The upper limit of the alkylene oxide units is not particularly limited. In preferred embodiments, the number of alkylene oxide units is 500 or less, more preferably 200 or less and even more preferably 150 or less.The alkylene oxide units are preferably selected from the group consisting of ethylene oxide, propylene oxide and butylene oxide, particularly preferably ethylene oxide and / or propylene oxide.

[0079] In a further preferred embodiment of the composition, the compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more have at least one (poly)alkylene oxide group of the formula -(C2H4-O)i-(C3H6-O) m -(C4H8-O)n- or -(C2H4- O)i-(C3H6-O) m-(C4H8-O)nH, where I, m and n are each independently a number of 0 or more, and where the sum of I, m and n is a number of 1 or more, preferably the sum of I, m and n is a number of 2 or more, preferably the sum of I, m and n is a number of 3 or more, more preferably 4 or more, even more preferably 5 or more, even more preferably 6 or more, even more preferably 8 or more, even more preferably 10 or more, even more preferably 12 or more, particularly preferably 15 or more, especially preferably 50 or more, and most preferably 100 or more. The upper limit of the alkylene oxide units is not particularly limited. In further embodiments, it is preferred that the sum of I, m and n is a number from 1 to 500, more preferably the sum of I, m and n is a number from 1 to 200 and even more preferably the sum of I, m and n is a number from 1 to 150.In a further particularly preferred embodiment, the sum of I, m and n is a number from 2 to 500, preferably the sum of I, m and n is a number from 2 to 200 and particularly preferably the sum of I, m and n is a number from 2 to 150. In a further preferred embodiment of the composition, the compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more have at least one (poly)alkylene oxide group of the formula -(CXH2X-O)Y- or -(C. x H2x-O) y-H, where x is a number 2, 3 or 4, and y is a number of 1 or more, preferably y is a number of 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 8 or more, 10 or more, 12 or more, 15 or more, 50 or more, 100 or more. The upper limit of the alkylene oxide units is not particularly limited. In further embodiments, it is preferred that y is a number from 1 to 500, more preferably y is a number from 1 to 200, and even more preferably y is a number from 1 to 150. In another particularly preferred embodiment, y is a number from 2 to 500, preferably y is a number from 2 to 200, and particularly preferably y is a number from 2 to 150.

[0080] In a further preferred embodiment of the composition, the molecular weight of the compounds having at least one alkylene oxide unit in their chemical structure is 250 g / mol or more, preferably 300 g / mol or more, more preferably 400 g / mol or more, even more preferably 500 g / mol or more, particularly preferably 1,000 g / mol or more, and particularly preferably 2,000 g / mol or more. The upper limit of the molecular weight of the compounds having at least one alkylene oxide unit in their chemical structure is not particularly limited. In preferred embodiments, the molecular weight of the compounds having at least one alkylene oxide unit in their chemical structure is 100,000 g / mol or less, preferably 50,000 g / mol or less, more preferably 25,000 g / mol or less, even more preferably 20,000 g / mol or less, particularly preferably 15,000 or less and particularly preferably 12,000 g / mol or less.

[0081] In a further preferred embodiment of the composition, the alkylene oxide units of the compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more are selected from the group consisting of ethylene oxide, propylene oxide, and butylene oxide. In a further preferred embodiment of the composition, the compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more are (poly)alkylene oxide adducts with at least one further radical selected from the group consisting of carboxylic acid radicals, carboxylic acid ester radicals, carboxamide radicals, phenol radicals, and alcohol radicals. The alkylene oxide units are preferably selected from the group consisting of ethylene oxide, propylene oxide, and butylene oxide, particularly preferably ethylene oxide and / or propylene oxide.

[0082] In a further preferred embodiment of the composition, the compounds having at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more are selected from the group consisting of polyglycols, polyalkylene glycols, block copolymers, carboxylic acid alkoxylates, carboxylic acid polyglycol esters, alkoxylated carboxylic acid esters, alkoxylated carboxylic acid amides, alkoxylated phenols, and alcohol alkoxylates. The alkylene oxide units are preferably selected from the group consisting of ethylene oxide, propylene oxide, and butylene oxide, particularly preferably ethylene oxide and / or propylene oxide.

[0083] In a further preferred embodiment of the composition, the compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more are polyglycols having the formula H-[O-C2H4] P -[O-C3H6]q-[O-C4H8] r-OH, where p, q and r are each independently a number of 0 or more, and the sum of p, q and r is a number of 5 or more, preferably the sum of p, q and r is a number of 6 or more, preferably 8 or more, more preferably 10 or more, even more preferably 12 or more, particularly preferably 15 or more, especially preferably 50 or more, and most preferably 100 or more. The upper limit of the alkylene oxide units is not particularly limited. In further embodiments, it is preferred that the sum of p, q and r is a number from 5 to 500, more preferably the sum of p, q and r is a number from 5 to 200, and even more preferably the sum of p, q and r is a number from 5 to 150.In a further particularly preferred embodiment, the sum of p, q and r is a number from 10 to 500, preferably the sum of p, q and r is a number from 10 to 200 and particularly preferably the sum of p, q and r is a number from 10 to 150.

[0084] Description of the characters

[0085] Figure 1 shows a schematic arrangement for a continuous process for the reduction of aldehydes with two heatable double-jacketed columns.

[0086] Figure 2 shows a schematic arrangement for a continuous process for the reduction of aldehydes with a heatable double-jacketed column and an evaporation unit.

[0087] Figure 1 shows a schematic arrangement for a continuous process for the reduction of aldehydes using two heatable double-jacketed stainless steel columns. The product stream (A) to be purified is passed through two consecutive columns (1, 2), with the first column (1) containing an acidic SO 3 H ion exchanger and the downstream column (2) containing a basic NH 2 ion exchanger. The two columns (1, 2) can be operated, for example, at a temperature of 100 °C. The resulting purified product stream (B) contains reduced levels of aldehydes.

[0088] Figure 2 shows a schematic arrangement for a continuous process in which the product stream (A) to be purified is passed through a heatable jacketed column (1) containing an acidic SO 3 H ion exchanger. An evaporation unit is installed at the outlet of the column (1), which allows the released aldehydes to be removed from the exiting product stream via the gas phase using a vacuum (C). The column (1) can be operated, for example, at a temperature of 100 °C. The resulting purified product stream (B) contains reduced levels of aldehydes.

[0089] The following examples illustrate the features and advantages of the invention using various embodiments. Examples

[0090] Within the scope of the invention, investigations were conducted to reduce the aldehyde content of polyglycol compounds and various alkoxylates produced for experimental purposes at high alkoxylation temperatures. A sulfonic acid-functional ion exchanger "Lewatit SP 112 H" from Lanxess, referred to in the examples as "SO 2 H ion exchanger," was used as the cation exchanger. The product "Lewatit VP OC 1065" from Lanxess was used as the basic ion exchanger, hereinafter referred to as "NH 2 ion exchanger." The aldehydes contained in the chemical compositions were separated from other substances by HPLC after derivatization with 2,4-dinitrophenylhydrazine solution and measured and quantified by UV detection (following B. Reindl, HJ. Stan, J. Agric. Food Chem., 30 (1982) 849-854 and JR Dahlgran, MN Jameson, J. Assoc. Off. Anal. Chem., 71 / 3 (1988) 560-563).In the following examples, the term “ppm” refers to the amount of the measured substance or ions in mg per 1 kg of the composition.

[0091] Example 1: Treatment of alkoxylated rapeseed oil (18EO / 6PO) with SO3H or NH2 ion exchanger

[0092] To study the influence of the ion exchanger on the reduction of aldehydes, 100 g of alkoxylated rapeseed oil containing 18EO (equivalent to 18 ethylene oxide units) and 6PO (equivalent to 6 propylene oxide units) were stirred in a 150 mL beaker at 100 °C for 30 min. The experiment was carried out without and with 10 wt. % of the acidic SO3H or basic NFh ion exchanger, respectively. In the presence of an ion exchanger, it was separated after treatment, and the acetaldehyde and propionaldehyde contents of the remaining product were determined. The results are summarized in Table 1. The alkoxylated rapeseed oil containing 18EO and 6PO had an acetaldehyde content of 6840 ppm and a propionaldehyde content of 805 ppm before treatment. This experiment demonstrates that significant aldehyde reduction is achieved by the acidic SO 3 H ion exchanger. The basic N-F ion exchanger alone did not result in significant aldehyde reduction.

[0093] The number average molecular weight (M n ) of the alkoxylated rapeseed oil used was calculated as follows: 299.3 g / mol (rapeseed oil) + 18 * 44.05 g / mol (ethylene oxide) + 6 * 58.08 g / mol (propylene oxide) = 1,440.6 g / mol. The molecular weight of the rapeseed oil was derived from the saponification number of 187.5 mg KOH / g according to DIN EN ISO 3681, DGF C-V3.

[0094] Table 1: Influence of the ion exchanger on the aldehyde content of an alkoxylated rapeseed oil with 18EO and 6PO (initial value acetaldehyde: 6840 ppm, propionaldehyde: 805 ppm).

[0095] Example 2a: Treatment of alkoxylated rapeseed oil (18EO / 6PO) with SO3H and NFL ion exchanger

[0096] To investigate the influence of the combination of an acidic ion exchanger followed by a basic ion exchanger on the reduction of aldehydes, 100 g of alkoxylated rapeseed oil with 18EO and 6PO were stirred in a 150 mL beaker at 60 °C, 80 °C, or 100 °C for 15 or 30 min with 5 or 10 wt. % of the acidic SO 3 H ion exchanger (process step A). ​​After treatment, the ion exchanger was separated from the product, and a sample was taken to determine the aldehyde content. In the second process step B, 5 or 10 wt. % of the basic NH 2 ion exchanger was added to the product and stirred at various temperatures for 15 or 30 min. The ion exchanger was then removed, and the aldehyde content was determined. The alkoxylated rapeseed oil with 18EO and 6PO had an acetaldehyde content of 7050 ppm and a propionaldehyde content of 990 ppm before treatment. The results are summarized in Table 2a.From this series of experiments it is evident that a combined treatment first with an acidic and then with a basic NH2 ion exchanger enables a significant aldehyde reduction, with a higher proportion of ion exchanger and a higher temperature of 100 °C favoring the reduction.

[0097] The number average molecular weight (M n ) of the alkoxylated rapeseed oil used was calculated as follows: 299.3 g / mol (rapeseed oil) + 18 * 44.05 g / mol (ethylene oxide) + 6 * 58.08 g / mol (propylene oxide) = 1,440.6 g / mol. The molecular weight of the rapeseed oil was derived from the saponification number of 187.5 mg KOH / g according to DIN EN ISO 3681, DGF C-V3.

[0098] Table 2a: Influence of a combination of ion exchangers on the aldehyde content of an alkoxylated rapeseed oil + 18EO + 6PO.

[0099] Example 2b: Treatment of alkoxylated sorbitan monolaurate (20 EO) with SO3H and NH2 ion exchanger

[0100] The test procedure corresponds to Example 2a), but instead of the alkoxylated rapeseed oil with 18EO and 6PO, a sorbitan monolaurate with 20EO was investigated. The sorbitan monolaurate with 20EO had an acetaldehyde content of 1070 ppm before treatment. The results are summarized in Table 2b. From this series of experiments, it is evident that a combined treatment with an acidic and subsequent treatment with a basic ion exchanger enables a significant aldehyde reduction. The number-average molecular weight (M n ) of the alkoxylated sorbitan monolaurate used was calculated as follows: 541.5 g / mol (sorbitan monolaurate) + 20 * 44.05 g / mol (ethylene oxide) = 1,422.5 g / mol.

[0101] Table 2b: Influence of a combination of ion exchangers on the aldehyde content of an ethoxylated sorbitan monolaurate + 20EO.

[0102] Example 2c: Treatment of alkoxylated isotridecyl alcohol (7 EO) with SO3H and NH2 ion exchanger

[0103] The experimental procedure corresponds to Example 2a), but instead of the alkoxylated rapeseed oil with 18EO and 6PO, an isotridecyl alcohol with 7EO was investigated. The isotridecyl alcohol with 7EO had an acetaldehyde content of 17 ppm before treatment. The results are summarized in Table 2c, showing that a combined treatment with an acidic and then a basic ion exchanger enables a significant aldehyde reduction. The number-average molecular weight (M n) of the ethoxylated isotridecyl alcohol used was calculated as follows: 196.9 g / mol (isotridecyl alcohol) + 7 * 44.05 g / mol (ethylene oxide) = 505.2 g / mol. The molecular weight of the isotridecyl alcohol was derived from the hydroxyl number as 285 mg KOH / g according to Ph. Eur. 2.5.3.

[0104] Table 2c: Influence of a combination of ion exchangers on the aldehyde content of an ethoxylated isotridecyl alcohol + 7EO.

[0105] Reference Example 3a: Treatment of ethoxylated coconut fatty acid (9EO) by steam distillation

[0106] 350 g of ethoxylated coconut fatty acid with 9EO were weighed into a steam distillation apparatus consisting of a 500 mL flask with a distillation head, steam inlet tube, and a stirring unit. The product was heated to 105 °C with stirring. When 105 °C was reached, saturated steam was introduced over a period of 240 min, with the distillate being collected in a receiver. When the temperature reached 105 °C, a sample was taken (corresponding to a residence time of 0 min) and then after steam treatment of 60 or 240 min at 105 °C. The samples were analyzed for their aldehyde and 1,4-dioxane content. The results are summarized in Table 3a. Before treatment, the coconut fatty acid ethoxylate had a formaldehyde content of 58 ppm, an acetaldehyde content of 2740 ppm and a 1,4-dioxane content of 3200 ppm.

[0107] The number average molecular weight (M n) of the ethoxylated coconut fatty acid used was calculated as follows: 209.0 g / mol (coconut fatty acid) + 9 * 44.05 g / mol (ethylene oxide) = 605.4 g / mol. The molecular weight of the coconut fatty acid was derived from the acid number of 268.5 mg KOH / g according to DIN EN ISO 3682.

[0108] Table 3a (reference example): Aldehyde and 1,4-dioxane content of an ethoxylated coconut fatty acid with 9EO treated by steam distillation at 105 °C for 240 min.

[0109] Example 3b: Treatment of ethoxylated coconut fatty acid (9EO) using SO3H ion exchanger and steam distillation

[0110] The experimental procedure was the same as in Example 3a, except that 2 wt.% of the acidic SO 3 H ion exchanger was added to the ethoxylated coconut fatty acid with 9EO at the beginning. The results are summarized in Table 3b. As Table 3b shows in comparison to Table 3a, the presence of an acidic SO 3 H ion exchanger had a significant impact on reducing the aldehyde content. The 1,4-dioxane content could also be reduced.

[0111] Table 3b: Aldehyde and 1,4-dioxane content of an ethoxylated coconut fatty acid with 9EO treated by steam distillation at 105 °C in the presence of an SO 5 H ion exchanger for 240 min.

[0112] Example 3c: Treatment of ethoxylated coconut fatty acid (9EO) using methanesulfonic acid and steam distillation

[0113] The experimental procedure corresponds to Example 3a, whereby 0.5 wt.% methanesulfonic acid was initially added to the ethoxylated coconut fatty acid with 9EO. The results are summarized in Table 3c. As Table 3c shows in comparison to Table 3a, the presence of methanesulfonic acid had a significant impact on reducing the aldehyde content. The 1,4-dioxane content could also be reduced. Table 3c: Aldehyde and 1,4-dioxane content of an ethoxylated coconut fatty acid with 9EO, which was treated by steam distillation at 105 °C in the presence of methanesulfonic acid for 240 min.

[0114] Reference Example 4a: Treatment of ethoxylated coconut fatty acid (9EO) by distillation

[0115] In a distillation apparatus consisting of a 500 mL flask with a distillation head and a stirring unit, 350 g of an ethoxylated coconut fatty acid with 9EO were weighed and 35 g of water were added. The coconut fatty acid with 9EO was produced by ethoxylating coconut fatty acid with ethylene oxide using caustic potash as a catalyst. The mixture of coconut fatty acid with 9EO and water was heated to 80 °C with stirring, and a sample was taken when a temperature of 80 °C was reached (corresponding to a residence time of 0 min). A vacuum was then applied (final pressure: 200 mbar), and the water and byproducts were distilled off. Samples were taken after 60 and 240 min, respectively, while breaking the vacuum. The samples were analyzed for their aldehyde, 1,4-dioxane, and potassium content. The results are summarized in Table 4a.Before treatment, the coconut fatty acid ethoxylate had a formaldehyde content of 58 ppm, an acetaldehyde content of 2740 ppm, a 1,4-dioxane content of 3200 ppm, and a potassium content of 1100 ppm. The number-average molecular weight (M n ) of the ethoxylated coconut fatty acid used was calculated as follows: 209.0 g / mol (coconut fatty acid) + 9 * 44.05 g / mol (ethylene oxide) = 605.4 g / mol. The molecular weight of the coconut fatty acid was derived from the acid number of 268.5 mg KOH / g according to DIN EN ISO 3682.

[0116] Table 4a (reference example): Aldehyde, 1,4-dioxane and potassium contents of an ethoxylated coconut fatty acid with 9EO treated by distillation at 80 °C under vacuum with 10 wt% water for 240 min.

[0117] Example 4b: Treatment of ethoxylated coconut fatty acid (9EO) using SO3H ion exchanger and distillation

[0118] The experimental procedure corresponds to Example 4a, whereby 2 wt. % of the acidic SO 3 H ion exchanger was added to the ethoxylated coconut fatty acid with 9EO with water at the beginning. The results are summarized in Table 4b. As Table 4b shows in comparison to Table 4a, the presence of an acidic SO 3 H ion exchanger has a significant influence on the reduction of the aldehyde content. The 1,4-dioxane content could also be reduced. Furthermore, the potassium content could be significantly reduced by using a cation exchanger, with the potassium ions originating from the use of caustic potash as a catalyst in the ethoxylation reaction. Therefore, the process according to the invention can be used to produce products that have a reduced content of aldehydes, 1,4-dioxane, and cations, relative to the starting value.

[0119] Table 4b: Aldehyde, 1,4-dioxane and potassium contents of an ethoxylated coconut fatty acid with 9EO treated by distillation at 80 °C under vacuum in the presence of an SO 5 H ion exchanger and 10 wt% water for 240 min.

[0120] Example 5: Purification of alkoxylated rapeseed oil (18EO / 6PO) using columns equipped with SO3H ion exchanger or NH2 ion exchanger

[0121] For the experiment, a continuous process for the reduction of aldehydes was used, using two heatable, sequentially connected double-jacketed stainless steel columns (as shown in Figure 1) with a volume of approximately 250 cm 3and a feed pump with a flow rate of approximately 2 g / min were used. The first column was filled with approximately 150 g of the acidic SO 5 H ion exchanger, and the downstream column with approximately 150 g of a basic NF 4 H ion exchanger. Both columns were operated at a temperature of 100 °C. The liquid product stream consisted of an alkoxylated rapeseed oil with 18EO and 6PO with an initial acetaldehyde content of 6840 ppm and a propionaldehyde content of 805 ppm. After a pre-run of 2 h, a sample of approximately 20 g was taken every hour from the exiting product stream and analyzed for aldehyde content. The results are summarized in Table 5. The results from Table 5 show that the aldehyde content can be reduced by more than 90% under the above conditions.

[0122] The number average molecular weight (M n) of the alkoxylated rapeseed oil used was calculated as follows: 299.3 g / mol (rapeseed oil) + 18 * 44.05 g / mol (ethylene oxide) + 6 * 58.08 g / mol (propylene oxide) = 1,440.6 g / mol. The molecular weight of the rapeseed oil was derived from the saponification number of 187.5 mg KOH / g according to DIN EN ISO 3681, DGF C-V3.

[0123] Table 5: Time evolution of the aldehyde content of an alkoxylated rapeseed oil containing 18EO and 6PO, treated by a continuous process according to Figure 1.

[0124] Example 6: Purification of polyethylene glycol 400 using columns equipped with SO5H ion exchanger or NH2 ion exchanger

[0125] The experiment was carried out analogously to Example 5, whereby the product stream consisted of polyethylene glycol 400 with an initial formaldehyde content of 68 ppm. The results are summarized in Table 6. The results from Table 6 show that the formaldehyde content can be reduced by more than 90% under the above conditions. The number-average molecular weight (M n ) of the polyethylene glycol 400 used with 399.4 g / mol was derived from the hydroxyl number of 281 mg KOH / g according to Ph. Eur. 2.5.3.

[0126] Table 6: Time evolution of the formaldehyde content of a polyethylene glycol 400 treated by a continuous process according to Figure 1.

[0127] Example 7: Purification of alkoxylated rapeseed oil (18EO / 6PO) using a column equipped with SO3H ion exchanger followed by an evaporation unit

[0128] For the experiment, a continuous process for the reduction of aldehydes was used, using a heatable double-jacketed stainless steel column (as shown in Figure 2) with a volume of approximately 250 cm 3and a feed pump with a flow rate of approximately 2 g / min was used. An evaporation unit was installed at the column outlet, which allowed the released aldehydes to be removed from the outgoing product stream via the gas phase using a vacuum (approximately 200 mbar). The column was filled with approximately 150 g of the acidic SO 3 H ion exchanger. The column was operated at a temperature of 100 °C. The liquid product stream consisted of an alkoxylated rapeseed oil with 18EO and 6PO with an initial acetaldehyde content of 6440 ppm and a propionaldehyde content of 818 ppm. After a pre-run of 2 h, a sample of approximately 20 g was taken from the outgoing product stream every hour and analyzed for aldehyde content. The results are summarized in Table 7.

[0129] The results from Table 7 show that the aldehyde content can be reduced by more than 60% under the above conditions.

[0130] The number average molecular weight (M n ) of the alkoxylated rapeseed oil used was calculated as follows: 299.3 g / mol (rapeseed oil) + 18 * 44.05 g / mol (ethylene oxide) + 6 * 58.08 g / mol (propylene oxide) = 1,440.6 g / mol. The molecular weight of the rapeseed oil was derived from the saponification number of 187.5 mg KOH / g according to DIN EN ISO 3681, DGF C-V3.

[0131] Table 7: Time evolution of the aldehyde content of an alkoxylated rapeseed oil containing 18EO and 6PO, treated by a continuous process according to Figure 2.

Claims

Patent claims 1. A process for the at least partial removal of aldehydes from a composition, the process comprising the following steps: a) contacting the composition with at least one cation exchanger and / or an acid at a temperature of 20.0 °C to 250.0 °C; b) at least partial separation of the aldehydes from the composition and optionally treatment of the separated aldehydes selected from the group consisting of condensation, absorption, adsorption, chemical bonding, chemical conversion, oxidation, and pyrolysis; whereby a composition with a reduced content of aldehydes is obtained; wherein the composition to be treated in step a) contains at least one compound having at least one alkylene oxide unit in its chemical structure and a molecular weight of 200 g / mol or more, and Contains 3.5% by weight or less of alcohols having 1 to 6 carbon atoms based on the total weight of the composition.

2. The process according to claim 1, characterized in that step a) is carried out at a temperature of 40 °C to 140 °C 3. The process according to claim 1 or 2, characterized in that the cation exchanger used in step a) is an acidic cation exchanger containing acid groups selected from the group consisting of -SO3H, -COOH, and -OP(OH)3.

4. The process according to claim 1 or 2, characterized in that the acid used in step a) is selected from the group consisting of sulfuric acid, phosphoric acid, phosphonic acid, phosphinic acid, hydrochloric acid, methanesulfonic acid, toluenesulfonic acid and alkylbenzenesulfonic acid, preferably methanesulfonic acid.

5. The process according to any one of claims 1 to 4, characterized in that step b) is carried out by a thermal separation process selected from the group consisting of distillation processes, rectification processes, stripping processes and flash evaporation processes.

6. The process according to any one of claims 1 to 4, characterized in that step b) is carried out by bringing into contact with an ion exchanger having amino or bisulfite functional groups, wherein step b) is preferably carried out at a temperature of 20 °C to 250 °C.

7. The process according to any one of claims 1 to 6, characterized in that the content of compounds having at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more in the composition used is at least 10 wt.% based on the total weight of the composition.

8. The process according to any one of claims 1 to 7, characterized in that after step b) a composition is obtained in which the total content of aldehydes is reduced by at least 10% of the initial value.

9. The process according to any one of claims 1 to 8, characterized in that after step b) a composition is obtained in which the total content of aldehydes is reduced to 1000 ppm or less.

10. The process according to any one of claims 1 to 9, characterized in that step b) is carried out by a thermal separation process selected from the group consisting of distillation processes, rectification processes, stripping processes and flash evaporation processes, wherein after step b) a composition is obtained in which the content of dioxane is reduced to 1000 ppm or less.

11. Process according to any one of claims 1 to 10, characterized in that the compounds containing at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more, have at least one (poly)alkylene oxide group, with at least 1, preferably with at least 2, more preferably with at least 3, more preferably with at least 4 and even more preferably with at least 5 alkylene oxide units.

12. Process according to any one of claims 1 to 11, characterized in that the compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more are (poly)alkylene oxide adducts with at least one further radical selected from the group consisting of carboxylic acid radicals, carboxylic acid ester radicals, carboxamide radicals, phenol radicals and alcohol radicals.

13. Process according to any one of claims 1 to 11, characterized in that the compounds which have at least one alkylene oxide unit in their chemical structure and a molecular weight of 200 g / mol or more are selected from the group consisting of polyglycols, polyalkylene glycols, block copolymers, carboxylic acid alkoxylates, carboxylic acid polyglycol esters, alkoxylated carboxylic acid esters, alkoxylated carboxylic acid amides, alkoxylated phenols and alcohol alkoxylates.

14. Composition containing at least one compound having at least one alkylene oxide unit in its chemical structure and a molecular weight of 200 g / mol or more, characterized in that the total content of aldehydes is 1000 ppm or less.

15. The composition according to claim 14, characterized in that the dioxane content is 1000 ppm or less.

16. The composition according to claim 14 or 15, characterized in that the content of metal ions is 1000 ppm or less.

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