Polyurethane-polyurea dispersions having a reduced content of free nitrogen compounds

Abstract

The present invention relates to the use of at least one organic dialkyl dicarbonate for reducing the content of nitrogen compounds in an aqueous polyurethane-polyurea dispersion containing at least one polyurethane-polyurea and at least one nitrogen compound, wherein the nitrogen compound is selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / or secondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol. The invention also relates to a process for producing an aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds, to an aqueous polyurethane-polyurea dispersion which is obtained or is obtainable by the process according to the invention, and also to an article, cosmetic, coating, adhesive layer, coating formulation, adhesive formulation and / or cosmetic formulation which is obtainable therefrom.

Description

[0001] Polyurethane-polyurea dispersions having a reduced content of free nitrogen compounds

[0002] The present invention relates to the use of at least one organic dialkyl dicarbonate for reducing the content of nitrogen compounds in an aqueous polyurethane-polyurea dispersion containing at least one polyurethane-polyurea and at least one nitrogen compound, wherein the nitrogen compound is selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / or secondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol. The invention also relates to a process for producing an aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds, to an aqueous polyurethane-polyurea dispersion which is obtained or is obtainable by the process according to the invention, and also to an article, cosmetic, coating, adhesive layer, coating formulation, adhesive formulation and / or cosmetic formulation which is obtainable therefrom.

[0003] Aqueous polyurethane dispersions may contain traces of primary and / or secondary amines and hydrazine, for example from incompletely reacted units such as chain-extending, chain-branching or chain-terminating amines which were each provided for converting isocyanate groups to urea. Depending on the circumstances, for example when adding a molar excess of isocyanate-reactive primary and / or secondary amines and hydrazine in the presence of other isocyanate-reactive substances, for instance water or by retrocleavage or urea groups that are already present. Many substances having primary and / or secondary amino groups and also hydrazine are classified as hazardous substances; therefore, the remaining content of these substances in aqueous polyurethane dispersions should ideally be kept as low as possible. Generally speaking, the substances used in polyurethane synthesis having primary and / or secondary amino groups and also hydrazine have a boiling point of greater than 100°C (at 1 atm) or form an azeotrope with water and can therefore not be easily removed by distillation from aqueous systems.

[0004] US3763058A, US3475377A and US3461102A describe the utilization of dicarbonates for modifying the end groups of polyurethane-polyurea polymers.

[0005] US3305533A describes the reaction of hydrazine monocarboxylic acid esters with organic dicarbonates in polyurethane solutions in organic solvents.

[0006] US 11193039B2 describes the utilization of organic dicarbonates in aqueous urethane-acrylate dispersions as an additive, in a function as an antioxidant or as an inhibitor against free-radical polymerization.

[0007] EP162364B1 describes the encapsulation of solid polyisocyanate particles in suspensions, wherein reactive groups of the capsule shell can be deactivated using organic dicarbonates. The use of organic dicarbonates for reducing the content of substances having primary and / or secondary amino groups and also hydrazine in aqueous polyurethane-polyurea dispersions is not described in the prior art.

[0008] It is an object of the present invention to provide an aqueous polyurethane-polyurea dispersion having a low content of primary and secondary amines and also hydrazine, which has consistently high quality and consistently good performance properties up to the time of its processing, in particular by the customer, and is also suitable for being processed in particular for the production of articles, cosmetics, coatings, adhesives or adhesive layers. To ensure long-term stabilization of the aqueous polyurethane-polyurea dispersion, it should be possible to reduce the content of primary and secondary amines and also hydrazine in the presence of established biocides such as isothiazolinones such as 5-chloro-2-methylisothiazolinone and 2-methylisothiazolinone.

[0009] It is a further object of the present invention to provide a process for producing an aqueous polyurethane-polyurea dispersion having a reduced amount of primary and secondary amines and also hydrazine.

[0010] These objects are achieved by the use according to the invention of at least one organic dialkyl dicarbonate for reducing the content of nitrogen compounds in an aqueous polyurethane-polyurea dispersion containing at least one polyurethane-polyurea and at least one nitrogen compound, wherein the nitrogen compound is selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / or secondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol.

[0011] These objects are further achieved by the process according to the invention for producing an aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds, comprising at least the steps of:

[0012] (A) providing an aqueous polyurethane-polyurea dispersion containing at least one polyurethane- polyurea and at least one nitrogen compound selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / or secondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol;

[0013] (B) treating the aqueous polyurethane-polyurea dispersion from step (A) with at least one organic dialkyl dicarbonate; to obtain an aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds. These objects are further achieved by the aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds, which is obtained or is obtainable by the process according to the invention.

[0014] Surprisingly, it was found that the use according to the invention, and also the process according to the invention, made it possible to reduce the content of primary and secondary amines and also hydrazine in aqueous polyurethane-polyurea dispersions by using at least one organic dialkyl dicarbonate, without reducing the quality and performance properties of the dispersion. It is further possible to reduce the content of primary and secondary amines and also hydrazine in the presence of established biocides such as isothiazolinones, thereby making it possible to reduce operating steps and optimize production operations. It is possible for example to reduce the duration of production of aqueous polyurethane-polyurea dispersions. In the production of aqueous polyurethane-polyurea dispersions, it may further be advantageous in the chain-extending of isocyanate-functional prepolymers to add a molar excess of hydrazine or secondary or primary amines relative to the isocyanate groups present, in order to influence the end group functionality of the polymers. A method of reducing the content of free primary and secondary amines and also hydrazine therefore makes it possible to provide products which have hitherto not been viably producible, in terms of the duration of the production process or chemicals legislation labelling of the product.

[0015] The present invention is described in detail below.

[0016] In the context of the invention, “reducing the content of nitrogen compounds” or “reduced content of nitrogen compounds” is understood to mean that the content of nitrogen compounds in the aqueous polyurethane-polyurea dispersion is lower 24 hours after the addition or use of the at least one organic dialkyl dicarbonate than, or relative to, the content of nitrogen compounds in the aqueous polyurethane-polyurea dispersion before the addition or use of the at least one organic dialkyl dicarbonate, wherein the nitrogen compound / nitrogen compounds is / are selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / or secondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol. The expression “have no carbonyl groups” means that there are no covalently bonded carbonyl groups as structural components present in the amines, in particular that there are no carbonyl groups as part of a ketone, aldehyde, ester, carbamate, urethane, urea, carbazate, amide, hydrazide or a carboxylic acid present in the amines. In the context of the invention, “reducing the content of nitrogen compounds” or “reduced content of nitrogen compounds” is preferably understood to mean that at least one primary and / or secondary amine group in the amines, and at least one NH2 group in hydrazine, have reacted with the at least one organic dialkyl dicarbonate to give the corresponding carbamates or carbazates. The at least one nitrogen compound is distinct from the at least one polyurethane-polyurea. Preferably, the content of nitrogen compounds in the aqueous polyurethane- polyurea dispersion 24 hours after the addition or use of the at least one organic dialkyl dicarbonate is reduced by more than 80% by weight, particularly preferably more than 90% by weight, more preferably more than 95% by weight, yet more preferably more than 98% by weight, relative to the content of nitrogen compounds in the aqueous polyurethane-polyurea dispersion before the addition or use of the at least one organic dialkyl dicarbonate, wherein the nitrogen compound / nitrogen compounds is / are selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / or secondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol. In a further step, the reaction product of the nitrogen compound / nitrogen compounds which is / are selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / or secondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol, with the organic dialkyl dicarbonate, can react again once and / or multiple times with an organic dialkyl dicarbonate. Preferably, the content of nitrogen compounds in the aqueous polyurethane-polyurea dispersion 24 hours after the addition or use of the at least one organic dialkyl dicarbonate is in the range from 0% by weight to 0. 1% by weight, particularly preferably in the range from 0% by weight to 0.01% by weight, relative to the total weight of the aqueous dispersion as 100% by weight, wherein the nitrogen compound / nitrogen compounds is / are selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / or secondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol. The content or concentration of nitrogen compounds in the aqueous polyurethane-polyurea dispersion is / was determined or measured as follows:

[0017] The concentrations of free hydrazine were determined by UPLC-UV after derivatization with acetone. To this end, 0.5 g of sample, 6.0 g of water and 0.5 g of 10% CaC12 solution in water were mixed. After 2 hours of mixing time, the solution was centrifuged and 1000 pl of the supernatant and 50 pl of acetone were combined in a 1.5 ml HPLC vial and mixed. This sample was used for injection into an HPLC system having an ACQUITY HSS T3 column (Waters Corporation, Milford, MA, USA). The system was calibrated using a corresponding analysis of a sample which has a known content of hydrazine.

[0018] The concentration of amines, for example ethylenediamine, was determined by gas chromatography following extraction with diethyl ether. The carrier gas was helium and decane was used as internal reference. The signals were detected using a FID detector; the area ratios were evaluated and used to ascertain the amine content.

[0019] In the context of the present invention, the word “a”or “an” in connection with countable parameters is to be understood as meaning the number “one” only when this is stated explicitly (for instance by the expression "precisely one"). When reference is made hereinbelow for example to “a polyisocyanate”, the word “a” is to be understood as meaning merely the indefinite article and not the number one; this therefore also covers an embodiment in which two or more, for example structurally dissimilar, polyisocyanates are present.

[0020] “Aqueous dispersion” in the context of the invention means an aqueous dispersion, aqueous emulsion, aqueous suspension, or an intermediate state / intermediate form thereof, preferably an aqueous dispersion, aqueous emulsion and / or aqueous suspension. Particularly preferably, the term “dispersion” means an aqueous emulsion and / or an aqueous suspension.

[0021] According to the invention, the terms “comprising” or “containing” preferably mean “consisting essentially of’ and particularly preferably mean “consisting of’. It should be noted that the features listed individually in the claims can be combined with one another in any technically useful way (even across category boundaries, for example between method and device) and demonstrate further configurations of the invention. The description additionally characterizes and specifies the invention.

[0022] It should also be noted that a conjunction “and / or” used herein between two features and linking them to one another is always to be interpreted in such a way that in a first configuration of the subject matter of the invention only the first feature can be present, in a second configuration only the second feature can be present and in a third configuration both the first and the second feature can be present.

[0023] The present invention relates to the use of at least one organic dialkyl dicarbonate for reducing the content of nitrogen compounds in an aqueous polyurethane-polyurea dispersion containing at least one polyurethane-polyurea and at least one nitrogen compound, wherein the nitrogen compound is selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / or secondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol.

[0024] In a preferred embodiment, the amines have a molecular weight in the range from 31 to 500 g / mol, preferably from 31 to 250 g / mol.

[0025] In a preferred embodiment, the amines are primary amines, preferably selected from the group consisting of ethane- 1,2-diamine, pentamethylene-l,5-diamine, hexamethylene- 1,6-diamine, 1- amino-3,3,5-trimethyl-5-aminomethylcyclohexane (isophorone diamine), 1,4-diaminocyclohexane and bis(4-aminocyclohexyl)methane.

[0026] According to the invention it is generally possible to use any polyurethane-polyurea known to those skilled in the art in aqueous dispersion. In a preferred embodiment, the at least one polyurethane-polyurea was obtained or is obtainable by reacting the following synthesis components:

[0027] (a) at least one diol and / or polyol component,

[0028] (b) at least one di- and / or polyisocyanate component;

[0029] (c) at least one component comprising at least one hydrophilizing group;

[0030] (d) at least one mono-, di- and / or tri-amino-functional and / or hydroxyamino-functional compound; and

[0031] (e) optionally other isocyanate-reactive compounds, wherein the components (a), (b), (c), (d) and (e) are distinct.

[0032] Preferably, at least one building block having a primary and / or secondary amino group is used in at least one of the components (c), (d) and (e). Alternatively, the at least one component having a primary and / or secondary amino group can be introduced in the aqueous polyurethane dispersion via another source, for example via an auxiliary and additive. It is also possible to introduce a plurality of different components having a primary and / or secondary amino group. It is also possible to introduce a component having a primary and / or secondary amino group in a plurality of steps and also when adding additives. It is also possible for components having a primary and / or secondary amino group to be partially independently brought to reaction but for a residual amount to remain in the system, and the content thereof to then be reduced according to the invention. A preferred example is the use of at least one of the components (c), (d) and (e) containing at least one primary and / or secondary amino group for reaction with isocyanate groups, forming urea. If the above operation for urea formation is not brought to completion, the content of excess unreacted primary and / or secondary amino groups can be reduced according to the invention. Primary and / or secondary amino groups on polymeric units can also be reacted according to the invention. A further possibility as a source of primary amino groups is isocyanates, of which the isocyanate groups hydrolyse in water and in which the amino groups formed are not reacted with at least one further isocyanate group to give urea. A further possibility as a source of primary and / or secondary amino groups are hydrolysis products of other components.

[0033] Suitable diol and / or polyol components (a) are compounds having at least two isocyanate-reactive hydrogen atoms and a number-average molecular weight (determined by GPC in THF as eluent at 23°C, calibrated using polystyrene standards) of preferably 62 to 18 000 g / mol, particularly preferably 62 to 4000 g / mol.

[0034] Examples of suitable synthesis components (a) are polyether polyols, polyester polyols, polycarbonate polyols, polylactones and polyamides. Preferred polyols (a) preferably have 2 to 4, particularly preferably 2 to 3 hydroxyl groups, very particularly preferably 2 hydroxyl groups. Mixtures of various such compounds are also possible. While the teaching of the present invention may in principle be realized with any dispersed polyurethane-polyurea polymer, the at least one polyurethane-polyurea present in the aqueous polyurethane-polyurea dispersion preferably contains as component (a) one or more polyester polyols and / or one or more polyether polyols and / or one or more polycarbonate polyols. In a preferred embodiment, the least one polyurethane-polyurea is based on polyether polyols and / or polyester polyols and / or polycarbonate polyols. In a preferred embodiment, the at least one polyurethane-polyurea is based on at least one polyester polyol, preferably polyester diol, and / or at least one polyether polyol, preferably polyether diol, and / or at least one polycarbonate polyol, preferably polycarbonate diol.

[0035] Suitable polyester polyols are in particular linear polyester diols or also sparsely branched polyester polyols, as can be produced in a known manner from aliphatic, cycloaliphatic or aromatic di- or polycarboxylic acids such as succinic acid, methylsuccinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, terephthalic acid, isophthalic acid, o-phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexanedicarboxylic acid, maleic acid, fumaric acid, malonic acid or trimellitic acid, and acid anhydrides such as o-phthalic, trimellitic or succinic anhydride or mixtures thereof with polyhydric alcohols, such as ethanediol, di-, tri-, tetraethylene glycol, propane- 1,2-diol, di-, tri-, tetrapropylene glycol, propane-1, 3-diol, butane- 1,4-diol, butane- 1,3 -diol, butane-2,3-diol, pentane-l,5-diol, hexane- 1,6-diol, 2, 2-dimethylpropane-1, 3-diol, 1,4-dihydroxycyclohexane, 1,4- dimethylolcyclohexane, octane-1, 8-diol, decane- 1,10-diol, dodecane- 1, 12-diol or mixtures thereof, optionally with the additional use of higher-functional polyols such as trimethylolpropane, glycerol or pentaerythritol. Cycloaliphatic and / or aromatic di- and polyhydroxyl compounds are of course also suitable as polyhydric alcohols for producing the polyester polyols. Instead of the free polycarboxylic acid, it is also possible to use for the production of the polyesters the corresponding polycarboxylic anhydrides or corresponding polycarboxylic esters of lower alcohols or mixtures thereof.

[0036] The polyester polyols may also be homopolymers or copolymers of lactones preferably obtained by addition reaction of lactones or lactone mixtures, such as butyrolactone, s-caprolactonc. and / or methyl-8-caprolactone, onto suitable di- and / or higher-functional starter molecules, for example the low-molecular-weight polyhydric alcohols mentioned above as synthesis components for polyester polyols. Preference is given to the corresponding polymers of 8-caprolactone.

[0037] Polycarbonates having hydroxyl groups are also suitable as polyhydroxyl components (a), for example those that can be produced by reacting diols such as butane- 1,4-diol and / or hexane- 1,6-diol with diaryl carbonates, for example diphenyl carbonate, dialkyl carbonates, for example dimethyl carbonate, or phosgene. The at least partial use of polycarbonates having hydroxyl groups can improve the resistance to hydrolysis of polyurethane-urea dispersion adhesives in the event that the aqueous polyurethane-polyurea dispersions are used for producing adhesives.

[0038] Examples of suitable polyether polyols are the polyaddition products of styrene oxides, of ethylene oxide, propylene oxide, tetrahydrofuran, butylene oxide, epichlorohydrin, and mixed addition and grafting products thereof, and also the polyether polyols obtained by condensation of polyhydric alcohols or mixtures of the same and obtained by alkoxylation of polyhydric alcohols, amines and amino alcohols. Polyether polyols particularly suitable as synthesis components (a) are homopolymers, copolymers and graft polymers of propylene oxide, ethylene oxide and tetrahydrofuran, which are accessible by addition of the epoxides mentioned or of tetrahydrofuran onto low-molecular-weight diols or triols, such as those mentioned above as synthesis components for polyester polyols, or onto higher-functional low-molecular-weight polyols such as pentaerythritol or sugar, or onto water.

[0039] Suitable components (a) are also low-molecular-weight diols, triols and / or tetraols such as ethanediol, di-, tri-, tetraethylene glycol, propane- 1,2-diol, di-, tri-, tetrapropylene glycol, propane- 1,3-diol, butane- 1,4-diol, butane-l,3-diol, butane-2,3-diol, pentane-l,5-diol, hexane- 1,6-diol, 2,2- dimethylpropane-l,3-diol, 1,4-dihydroxycyclohexane, 1,4-dimethylolcyclohexane, octane-1, 8-diol, decane- 1,10-diol, dodecane- 1,12-diol, neopentyl glycol, cyclohexane- 1,4-diol, cyclohexane- 1,4- dimethanol, 1,4-, 1,3-, 1,2-dihydroxybenzene or 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), TCD diol, trimethylolpropane, glycerol, pentaerythritol, dipentaerythritol or mixtures thereof, optionally with the additional use of other diols or triols not mentioned.

[0040] Polyols used may also be reaction products of the polyols mentioned, in particular of the low- molecular-weight polyols, with ethylene oxide and / or propylene oxide.

[0041] The low-molecular-weight components (a) preferably have a molecular weight of 62 to 400 g / mol and are further preferably used in combination with the polyester polyols, polylactones, polyether polyols and / or polycarbonate polyols described above.

[0042] The polyol component (a) is preferably present in the at least one polyurethane-polyurea used according to the invention in an amount of 20% to 94% by weight, particularly preferably 30% to 90% by weight and very particularly preferably 65% to 90% by weight, wherein the sum of the components (a), (b), (c), (d) and optionally (e) present in each case amounts to 100% by weight.

[0043] Suitable as components (b) are any organic compounds having at least two free isocyanate groups per molecule. Preference is given to using diisocyanates of general formula Y(NCO)2, wherein Y is a divalent aliphatic hydrocarbon radical having 4 to 12 carbon atoms, a divalent cycloaliphatic hydrocarbon radical having 6 to 15 carbon atoms, a divalent aromatic hydrocarbon radical having 6 to 15 carbon atoms or a divalent araliphatic hydrocarbon radical having 7 to 15 carbon atoms.

[0044] Examples of such diisocyanates to be preferably used are tetramethylene diisocyanate, methylpentamethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,4-diisocyanatocyclohexane, l-isocyanato-3,3,5-trimethyl-5- isocyanatomethylcyclohexane (isophorone diisocyanate; IPDI), 4,4'- diisocyanatodicyclohexylmethane, 4,4'-diisocyanato-2,2-dicyclohexylpropane, 1,4- diisocyanatobenzene, 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, 4,4'- diisocyanatodiphenylmethane, 2,2'- and 2,4'-diisocyanatodiphenylmethane, tetramethylxylylene diisocyanate, p-xylylene diisocyanate, p-isopropylidene diisocyanate, and mixtures consisting of these compounds.

[0045] In addition to these simple diisocyanates, polyisocyanates containing heteroatoms in the radical linking the isocyanate groups and / or having a functionality of more than 2 isocyanate groups per molecule are also suitable. The former are polyisocyanates having a uretdione, isocyanurate, urethane, allophanate, biuret, carbodiimide, iminooxadiazinedione and / or oxadiazinetrione structure that are prepared for example by modification of simple aliphatic, cycloaliphatic, araliphatic and / or aromatic diisocyanates and are composed of at least two diisocyanates. An example of an unmodified polyisocyanate having more than 2 isocyanate groups per molecule is, for example, 4- isocyanatomethyloctane 1,8 -diisocyanate (nonane triisocyanate).

[0046] Preferred diisocyanates (b) are pentamethylene diisocyanate, methylpentamethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,4-diisocyanatocyclohexane, 1- isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, 4,4'-diisocyanatodicyclohexylmethane,

[0047] 1.3- and l,4-bis(isocyanatomethyl)benzene, 1,3- and l,4-bis(l-isocyanato-l-methylethyl)benzene, bis(4-( 1 -isocyanato- 1 -methylethyl)phenyl) carbonate, 4,4'-diisocyanato-2,2-dicyclohexylpropane,

[0048] 1.4-diisocyanatobenzene, 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, 4,4'- diisocyanatodiphenylmethane, 2,2'- and 2,4'-diisocyanatodiphenylmethane, tetramethylxylylene diisocyanate, p-xylylene diisocyanate, p-isopropylidene diisocyanate, and mixtures consisting of these compounds.

[0049] Particularly preferred components (b) are 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, hexamethylene diisocyanate, 4,4'-diisocyanatodicyclohexylmethane, l-isocyanato-3,3,5-trimethyl- 5-isocyanatomethylcyclohexane, and also mixtures consisting of these compounds.

[0050] Component (b) is present in the at least one polyurethane-polyurea used according to the invention in an amount of generally 5% to 60% by weight, preferably 6% to 45% by weight and particularly preferably 7% to 25% by weight, wherein the sum of the components (a), (b), (c), (d) and optionally (e) present in each case amounts to 100% by weight.

[0051] Suitable components (c) are, for example, components comprising sulfonate or carboxylate groups, for example diamino compounds or dihydroxy compounds additionally bearing sulfonate and / or carboxylate groups, for example the sodium, lithium, potassium, tert-amine salts of N-(2- aminoethyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-2-aminoethanesulfonic acid, N-(3- aminopropyl)-3-aminopropanesulfonic acid, N-(2-aminoethyl)-3-aminopropanesulfonic acid, the analogous carboxylic acids, dimethylolpropionic acid, dimethylolbutyric acid, the reaction products in the sense of a Michael addition of 1 mol of diamine, for example ethane- 1,2-diamine or isophoronediamine, with 2 mol of acrylic acid or maleic acid.

[0052] The acids are preferably used directly in the form of their sulfonate or carboxylate salts. However, it is also possible to add some or all of the neutralizing agents necessary for salt formation only during or after production of the polyurethane-polyureas.

[0053] Tertiary amines particularly suitable and preferred for salt formation include for example triethylamine, dimethylcyclohexylamine and / or ethyldiisopropylamine. Other amines may also be used for salt formation, for example ammonia, diethanolamine, triethanolamine, dimethylethanolamine, methyldiethanolamine, aminomethylpropanol and also mixtures of the amines cited and also other amines. These amines are advantageously added only after formation of the prepolymer which consists of the components (a) and (b).

[0054] It is also possible to use, for neutralization purposes, other neutralizing agents, for example sodium, potassium, lithium and calcium hydroxides.

[0055] Further suitable components (c) are non-ionically hydrophilizing, mono- or difimctional polyethers based on alcohol- or amine-started ethylene oxide polymers or ethylene oxide / propylene oxide copolymers, for example polyether LB 25 (Covestro Deutschland AG, Leverkusen, Germany), diols having a polyether side chain containing ethylene oxide units (for example Ymer N120, Perstorp Holding AB, Malmo, Sweden) or MPEG 750, i.e. methoxypolyethylene glycol having a molecular weight of 750 g / mol, obtainable for example under the trade name Pluriol® 750 from BASF SE, Germany.

[0056] Preferred components (c) are N-(2-aminoethyl)-2-aminoethanesulfonate, N-(2-aminoethyl)-2- aminoethanecarboxylate, and the salts of dimethylolpropionic acid and dimethylolbutyric acid. Component (c) is preferably present in the at least one polyurethane-polyurea used according to the invention in an amount of 0.1% to 15% by weight, particularly preferably 0.5% to 10% by weight, very particularly preferably 0.8% to 5% by weight and yet more preferably 0.9% to 3.0% by weight, wherein the sum of the components (a), (b), (c), (d) and optionally (e) present in each case amounts to 100% by weight.

[0057] Suitable components (d) according to the invention are mono-, di-, trifunctional amines and / or mono- , di-, trifunctional hydroxyamines, for example aliphatic and / or alicyclic primary and / or secondary monoamines, for example methylamine, ethylamine, diethylamine, the isomeric propyl- and butylamines, higher linear aliphatic monoamines and cycloaliphatic monoamines, for example cyclohexylamine. Further examples are amino alcohols, i.e. compounds containing amino and hydroxyl groups in the same molecule, for example ethanolamine, N-methylethanolamine, diethanolamine, diisopropanolamine, 1, 3 -diamino-2 -propanol, N-(2-hydroxyethyl)ethylenediamine, N,N-bis(2-hydroxyethyl)ethylenediamine and 2-propanolamine.

[0058] Further examples are diamines and triamines, for example ethane- 1,2-diamine, hexamethylene- 1,6- diamine, l-amino-3,3,5-trimethyl-5-aminomethylcyclohexane (isophoronediamine), piperazine, 1,4- diaminocyclohexane, bis(4-aminocyclohexyl)methane, and diethylenetriamine. Adipic dihydrazide, hydrazine, and hydrazine hydrate are additionally suitable. It is of course also possible to use mixtures of a plurality of the compounds (d) mentioned, optionally also together with compounds (d) that are not mentioned.

[0059] Preferred components (d) are ethane- 1,2-diamine, l-amino-3,3,5-trimethyl-5- aminomethylcyclohexane, diethylenetriamine, diethanolamine, ethanolamine, N-(2- hydroxyethyl)ethylenediamine, and N,N-bis(2-hydroxyethyl)ethylenediamine.

[0060] Components (d) serve as di- or trifunctional chain extenders, preferably in order to build up higher molecular weights, or in the form of monofunctional compounds to limit molecular weights, and / or optionally as a means of incorporating additional reactive groups such as free hydroxyl groups. If (poly)amines (d) are not used, the polymers formed are pure polyurethanes which more preferably do not contain any urea groups.

[0061] Component (d) is preferably present in the at least one polyurethane-polyurea used according to the invention in an amount of 0.1% to 10% by weight, particularly preferably 0.2% to 5% by weight and very particularly preferably 0.5% to 3% by weight, wherein the sum of the components (a), (b), (c), (d) and optionally (e) present in each case amounts to 100% by weight. Components (e) for optional co-use according to the invention may be for example aliphatic, cycloaliphatic or aromatic monoalcohols having 2 to 22 C atoms, for example ethanol, butanol, hexanol, cyclohexanol, isobutanol, benzyl alcohol, stearyl alcohol, 2-ethylethanol.

[0062] Components (e) may preferably be present in the at least one polyurethane used according to the invention in an amount of 0% to 20% by weight, particularly preferably 0% to 10% by weight, wherein the sum of the components (a), (b), (c), optionally (d) and optionally (e) in each case amounts to 100% by weight.

[0063] The lateral and / or terminal carboxyl groups can in principle be incorporated into the polymer skeleton via any of the synthesis components (a) to (e). They are preferably incorporated via components (c), (d) and optionally (e).

[0064] Incorporation via component (c) can be accomplished for example by using dimethylolpropionic acid or dimethylolbutyric acid in the absence of neutralizing agent or with neutralizing agent added in a substoichiometric amount.

[0065] Compounds suitable for the incorporation of carboxyl groups as component (d) are, for example, those which contain only one isocyanate-reactive amino group and thus, in the production of the polyurethanes according to the invention, result in terminal carboxyl groups by reaction with the isocyanate component. Linear aliphatic, branched aliphatic, aliphatic-aromatic and aromatic aminocarboxylic acids are suitable. Examples include aminocarboxylic acids having a primary or secondary amino group, such as alanine, 6-aminohexanoic acid, aminoundecanoic acid, 8- aminooctanoic acid, 5 -aminopentanoic acid, 4-aminobutyric acid, aminobenzoic acid, 4- aminomethylcyclohexanecarboxylic acid, 2-aminohexanoic acid, 4-aminocyclohexanecarboxylic acid, 12-aminododecanoic acid and / or 9-aminononacarboxylic acid.

[0066] Compounds suitable for the incorporation of carboxyl groups as component (d) are, for example, diaminocarboxylic acids which each have 2 isocyanate-reactive amino groups and thus, in the production of the at least one polyurethane, result in lateral carboxyl groups by reaction with the isocyanate component. Examples of these are lysine, arginine and / or histidine.

[0067] Compounds suitable for the incorporation of carboxyl groups as component (e) are, for example, hydroxycarboxylic acids which contain only one hydroxyl group, for example hydroxypivalic acid, hydroxyacetic acid and / or 2-hydroxypropanoic acid.

[0068] In order to produce the aqueous polyurethane-polyurea dispersions, use may be made of any processes known from the prior art such as emulsifying shear force, acetone, prepolymer mixing, melt emulsification, ketimine and solid spontaneous dispersing processes or derivatives thereof. A summary of these methods can be found in Methoden der organischen Chemie [Methods of Organic Chemistry] (Houben-Weyl, Erweiterungs- und Folgebande zur 4. Auflage [Expansion and Supplementary Volumes for the 4th Edition], volume E20, H. Bartl and J. Falbe, Stuttgart, New York, Thieme 1987, pages 1671 to 1682). According to the invention, preference is given to the melt emulsification, prepolymer mixing, and acetone processes. Particular preference is given to the acetone process. The use and implementation of the acetone process is prior art and is known to those skilled in the art from EP -A 0 232 778, for example.

[0069] In a preferred embodiment, the at least one polyurethane-polyurea is present in an amount of 5 to 64% by weight, preferably 30 to 60% by weight, particularly preferably 40 to 50% by weight, in each case relative to the total aqueous polyurethane-polyurea dispersion.

[0070] The at least one organic dialkyl dicarbonate has the formula R-O-C(=O)-O-C(=O)-O-R', wherein R and R' are alkyl groups and R and R’ are preferably identical. Examples include dimethyl dicarbonate, diethyl dicarbonate and di-tert-butyl dicarbonate, preferably dimethyl dicarbonate and diethyl dicarbonate, very particularly preferably dimethyl dicarbonate.

[0071] In a preferred embodiment, the at least one organic dialkyl dicarbonate is selected from the group consisting of dimethyl dicarbonate, diethyl dicarbonate, dipropyl dicarbonate, diisopropyl dicarbonate, methyl ethyl dicarbonate, di-tert-butyl dicarbonate, diisobutyl dicarbonate and / or mixtures of at least two thereof; the organic dialkyl dicarbonate is preferably dimethyl dicarbonate, diethyl dicarbonate and / or a mixture thereof, and is particularly preferably dimethyl dicarbonate.

[0072] In a preferred embodiment, the at least one organic dialkyl dicarbonate is present in an amount of 0.001 g / kg to 100 g / kg, preferably of 0.1 g / kg to 50 g / kg, particularly preferably of 0.1 g / kg to 20 g / kg, relative to the total aqueous polyurethane-polyurea dispersion.

[0073] In a preferred embodiment, the content of nitrogen compounds in the aqueous polyurethane-polyurea dispersion before the addition or use of the at least one organic dialkyl dicarbonate is in the range from 0.0001% by weight to 5% by weight, preferably from 0.01% by weight to 1% by weight, relative to the total weight of the aqueous polyurethane-polyurea dispersion as 100% by weight, wherein the nitrogen compound or nitrogen compounds is / are selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / or secondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol.

[0074] In a preferred embodiment, the content of nitrogen compounds in the aqueous polyurethane-polyurea dispersion 24 hours after the addition or use of the at least one organic dialkyl dicarbonate is in the range from 0% by weight to 0. 1% by weight, particularly preferably from 0% by weight to 0.01% by weight, relative to the total weight of the aqueous dispersion as 100% by weight, wherein the nitrogen compound or nitrogen compounds is / are selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / or secondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol.

[0075] In a preferred embodiment, the content of nitrogen compounds in the aqueous polyurethane-polyurea dispersion 24 hours after the addition or use of the at least one organic dialkyl dicarbonate is reduced by more than 80% by weight, preferably more than 90% by weight, particularly preferably more than 95% by weight, yet more preferably more than 98% by weight, relative to the content of nitrogen compounds in the aqueous polyurethane-polyurea dispersion before the addition or use of the at least one organic dialkyl dicarbonate as 100% by weight, wherein the nitrogen compound or nitrogen compounds is / are selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / or secondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol.

[0076] The content of nitrogen compounds in the aqueous polyurethane-polyurea dispersion is / was determined or measured as follows:

[0077] The concentrations of free hydrazine were determined by UPLC-UV after derivatization with acetone. To this end, 0.5 g of sample, 6.0 g of water and 0.5 g of 10% CaC12 solution in water were mixed. After 2 hours of mixing time, the solution was centrifuged and 1000 pl of the supernatant and 50 pl of acetone were combined in a 1.5 ml HPLC vial and mixed. This sample was used for injection into an HPLC system having an ACQUITY HSS T3 column (Waters Corporation, Milford, MA, USA). The system was calibrated using a corresponding analysis of a sample which has a known content of hydrazine.

[0078] The concentration of amines, for example ethylenediamine, was determined by gas chromatography following extraction with diethyl ether. The carrier gas was helium and decane was used as internal reference. The signals were detected using a FID detector; the area ratios were evaluated and used to ascertain the amine content.

[0079] In a preferred embodiment, the aqueous polyurethane-polyurea dispersion contains at least one compound having a biocidal effect which is distinct from the organic dialkyl dicarbonate, wherein the at least one compound having a biocidal effect is preferably a bactericide, fungicide and / or algicide, particularly preferably at least one isothiazolinone, is more preferably selected from the group consisting of chloromethylisothiazolinone, methylisothiazolinone, benzisothiazolinone, octylisothiazolinone, butylbenzisothiazolinone, dichlorooctylisothiazolinone and / or mixtures of at least two thereof, is yet more preferably selected from the group consisting of 5-chloro-2- methylisothiazolinone / 2 -methylisothiazolinone and / or mixtures thereof, wherein the at least one compound having a biocidal effect is preferably present in an amount of 1 to 1000 mg / kg relative to the total aqueous polyurethane-polyurea dispersion.

[0080] In the context of the present invention, “having a biocidal effect” means that the corresponding compound can control microorganisms, in particular bacteria and / or fungi, and prevent them from reproducing or kill them.

[0081] Suitable compounds having a biocidal effect include all biocides known to those skilled in the art, for example algicides, bactericides, fungicides against fungi, insecticides, antimycotic agents against yeasts, and virucides.

[0082] The compound having a biocidal effect used is preferably at least one bactericide, fungicide against fungi, antimycotic agent against yeasts and / or a mixture of at least two thereof. The compound having a biocidal effect used is preferably at least one biocide for in-can preservation.

[0083] In addition to the aforementioned components the aqueous dispersion may also contain any component appearing suitable to a person skilled in the art. Examples of components additionally present include binders, biocides, in-can preservatives, assistant and additive substances, in particular emulsifiers and light stabilizers, in particular UV absorbers, also fillers and auxiliaries, in particular anti-settling agents, defoaming and / or wetting agents, levelling agents, reactive diluents , plasticizers, neutralizing agents, catalysts, auxiliary solvents, thickeners, additives, in particular pigments, dyes or matting agents, tackifiers, or mixtures thereof, known in coatings and adhesives technology.

[0084] In a preferred embodiment, the aqueous polyurethane-polyurea dispersion additionally contains components selected from binders, assistant and additive substances, fillers, auxiliaries, levelling agents, reactive diluents, plasticizers, neutralizing agents, catalysts, auxiliary solvents, thickeners, additives, tackifiers and mixtures thereof.

[0085] In a preferred embodiment of the use according to the invention, the at least one organic dialkyl dicarbonate is used in the process according to the invention for reducing the content of nitrogen compounds in an aqueous polyurethane-polyurea dispersion.

[0086] The present invention further prelates to a process for producing an aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds, comprising at least the steps of:

[0087] (A) providing an aqueous polyurethane-polyurea dispersion containing at least one polyurethane- polyurea and at least one nitrogen compound selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / or secondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol; (B) treating the aqueous polyurethane-polyurea dispersion from step (A) with at least one organic dialkyl dicarbonate; to obtain an aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds.

[0088] Details and preferred embodiments of the organic dialkyl dicarbonate and of the at least one compound having biocidal activity have already been described above and apply correspondingly to the use according to the invention. Details and preferred embodiments of the aqueous polyurethane- polyurea dispersion provided in step (A) of the process according to the invention have already been described above and apply correspondingly to the process according to the invention.

[0089] In a preferred embodiment, the amines have a molecular weight in the range from 31 to 500 g / mol, preferably from 31 to 250 g / mol.

[0090] In a preferred embodiment, the amines are primary amines, preferably selected from the group consisting of ethane- 1,2-diamine, pentamethylene-l,5-diamine, hexamethylene- 1,6-diamine, 1- amino-3,3,5-trimethyl-5-aminomethylcyclohexane (isophorone diamine), 1,4-diaminocyclohexane and bis(4-aminocyclohexyl)methane.

[0091] In the context of the present invention, "providing” means that the aqueous polyurethane-polyurea dispersion may be present in any form which appears suitable to those skilled in the art and in which it is possible to treat it according to step (B) of the process according to the invention. The aqueous polyurethane-polyurea dispersion is preferably provided in a container or reactor, for example a stirred reactor. The addition of the at least one organic dialkyl dicarbonate may further also be carried out after transferring the aqueous polyurethane-polyurea dispersion into a mixing vessel, in particular fitted with a stirrer or recirculation pump. The addition of the at least one organic dialkyl dicarbonate and the treatment of the aqueous polyurethane-polyurea dispersion with at least one organic dialkyl dicarbonate may also be carried out directly in the delivery container of the dispersion.

[0092] According to the invention, the aqueous dispersion has the concentrations of ingredients described above. However, it is also possible according to the invention for the aqueous polyurethane-polyurea dispersion to be diluted or concentrated before step (A). Suitable concentrations of the at least one polyurethane-polyurea present are 5 to 64% by weight, preferably 30 to 60% by weight, very particularly preferably 40 to 50% by weight, in each case relative to the total aqueous polyurethane- polyurea dispersion. According to the invention, the aqueous polyurethane-polyurea dispersion may be mixed with at least one further aqueous polymer dispersion, for example with an aqueous dispersion of at least one further film-forming polymer, before step (B) of the process according to the invention.

[0093] Step (B) of the process according to the invention can generally be carried out at any temperature that appears suitable to those skilled in the art. In a preferred embodiment, step (B) is carried out at 1°C to 100°C, preferably at 5°C to 50°C, particularly preferably at 10°C to 30°C.

[0094] Step (B) of the process according to the invention can generally be carried out at any pressure that appears suitable to those skilled in the art, preferably at atmospheric pressure.

[0095] In step (B) the aqueous polyurethane-polyurea dispersion may preferably be stirred, in particular using apparatuses known to those skilled in the art, in particular propeller stirrers, anchor stirrers, dissolver disks, helical stirrers, jet stirrers, for example Visco-Jet®. The mixing and / or dissolution in step (B) of the process according to the invention may also be carried out by pumped recirculation of the aqueous polyurethane-polyurea dispersion (A) using, for example, peristaltic pumps, diaphragm pumps, eccentric screw pumps.

[0096] Details and preferred embodiments of the at least one organic dialkyl dicarbonate used in step (B) of the process according to the invention have already been described above and apply correspondingly to the process according to the invention.

[0097] In the treatment in step (B), reaction of the at least one organic dialkyl dicarbonate in water, i.e. hydrolysis with the water of the polyurethane dispersion, releases at least one alcohol. Examples are the release of ethanol from diethyl dicarbonate or methanol from dimethyl dicarbonate. These alcohols may be removed from the product, for example by distillation, or may optionally also remain in the product mixture in part. The carbon dioxide formed in the reaction of the at least one organic dialkyl dicarbonate in the water, i.e. hydrolysis with the water of the polyurethane-polyurea dispersion, either remains physically dissolved in the dispersion, reacts with water to form carbonic acid or carbonates, and / or may be removed from the dispersion. Partial or complete removal of the carbon dioxide formed is possible by heating the dispersion or by applying vacuum.

[0098] Before adding the at least one organic dialkyl dicarbonate to the aqueous polyurethane-polyurea dispersion, the dialkyl dicarbonate may be dissolved in a suitable solvent. Examples include water- miscible solvents, for example water, monoalcohols, for example methanol or ethanol, glycols, for example propylene glycol, ketones, for example acetone or 2-butanone, or N-alkyl pyrrolidones such as N-methyl-2 -pyrrolidone, N-ethyl-2 -pyrrolidone or N-butyl -2 -pyrrolidone. Use is preferably made of solvents which do not decompose the organic dialkyl dicarbonate or deactivate its effect. Further additives may also be added to the dialkyl dicarbonate before addition to the aqueous dispersion. In a preferred variant, the dialkyl dicarbonate is added in pure form, i.e. without further premixing or pre-dilution.

[0099] In a preferred embodiment, metered addition of the at least one organic dialkyl dicarbonate is effected via a nozzle. In a further preferred embodiment, metered addition of the at least one organic dialkyl dicarbonate is effected via a mixing apparatus. In a further preferred embodiment, the added amount and metered addition rate of the at least one organic dialkyl dicarbonate is controlled using a liquid flowmeter unit and a metering unit coupled thereto.

[0100] What is ultimately obtained after step (B) of the process according to the invention as a result of reactions including the hydrolysis of the at least one organic dialkyl dicarbonate is an aqueous polyurethane-polyurea dispersion which is largely free of the organic dialkyl dicarbonate used. Before it is applied or used, the aqueous polyurethane-polyurea dispersion obtained preferably no longer contains any organic dialkyl dicarbonate.

[0101] According to the invention, it is possible to add at least one compound having a biocidal effect which is distinct from the at least one organic dialkyl dicarbonate before, after or simultaneously with step

[0102] (B).

[0103] However, it is also possible for the aqueous polyurethane-polyurea dispersion obtained in step (B) to be supplied to further workup steps, for example the addition of thickeners, pigments, colour pastes, further processing auxiliaries, for example defoamers, wetting auxiliaries, coagulation auxiliaries and / or stabilizers, for example further antioxidants and UV stabilizers, that are suitable for the further processing. Processes for adding the components mentioned are known per se to those skilled in the art.

[0104] According to the invention, it is possible for the aqueous dispersion to be used after step (B) for producing articles, cosmetics, coatings, adhesive layers or adhesives.

[0105] In a preferred embodiment, step (B) is followed by at least the following step (C):

[0106] (C) production of articles, cosmetics, coatings, adhesive layers or adhesives from the aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds obtained in step (B). Appropriate processes carried out in step (C) of the process according to the invention are known per se to those skilled in the art, for example

[0107] • dip coating, in particular for the production of gloves, preferably for use in the medical field,

[0108] • production of aqueous adhesive dispersions that are processed with and without crosslinkers, for example isocyanate or polycarbodiimide crosslinkers,

[0109] • production of latent-reactive adhesive layers, adhesive films or adhesive powders, for example described in EP -A 0 922 720 or EP 2 099 840 Bl,

[0110] • production and / or coating of textiles, leather or synthetic leather and microfibre-based textiles or synthetic leather,

[0111] • use of polyurethane dispersion in hairspray, sunscreens, etc.,

[0112] • use in sizes in the production of carbon fibres, glass fibres or fibres of other mineral materials which are preferably used for producing fibre-reinforced composite materials,

[0113] • coatings on plastics, metallic materials, wood, composite materials, ceramic materials, mineral substrates such as stone,

[0114] • and also on previously coated substrates.

[0115] Preferred articles according to the invention are selected for example from articles produced by dip coating, for example disposable gloves or condoms, covers or sleeves for medical devices, probes, endoscopes, coated textiles, bandages, films for wound dressings, medical foams or wearable patches.

[0116] Cosmetics preferred according to the invention are selected for example from hairspray, sun cream, conditioner or mascara, etc., wherein the at least one polyurethane-polyurea used serves more preferably here as a film-former.

[0117] Coatings preferred according to the invention are selected for example from primer, filler, base coat and top coat systems, coatings of wood, metal and plastics, textiles, leather, synthetic leather, each in various industries, for example in cars, large vehicles, ACE (agricultural, construction & earth moving equipment), industrial coatings, furniture or fibreglass sizing.

[0118] Adhesives preferred according to the invention are selected for example from polyurethane dispersion adhesives and polyurethane-polyurea dispersion adhesives which are processed as either 1- or 2-component systems, non-reactive and reactive adhesive films, adhesive powders or adhesive layers, in each case applied to substrate surfaces. The present invention also relates to an aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds, which is obtained or is obtainable by the process according to the invention. Details and preferred embodiments of the aqueous polyurethane dispersion, of the organic dialkyl dicarbonate, and also of the at least one compound having a biocidal effect have already been described above and apply correspondingly to the aqueous polyurethane-polyurea dispersion according to the invention having a reduced content of nitrogen compounds, which is obtained or is obtainable by the process according to the invention.

[0119] The present invention also relates to articles, cosmetics, coating, adhesive layer, coating formulation, adhesive formulation and / or cosmetic formulation containing at least the aqueous polyurethane- polyurea dispersion according to the invention having a reduced content of nitrogen compounds.

[0120] Various aspects of the subject matter described herein are set out in the following numbered clauses: Clause 1. Use of at least one organic dialkyl dicarbonate for reducing the content of nitrogen compounds in an aqueous polyurethane-polyurea dispersion containing at least one polyurethane- polyurea and at least one nitrogen compound, wherein the nitrogen compound is selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / or secondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol.

[0121] Clause 2. The use of clause 1, characterized in that the amines have a molecular weight in the range from 31 to 500 g / mol, preferably from 31 to 250 g / mol.

[0122] Clause 3. The use of clause 1 or 2, characterized in that the amines are primary amines, preferably selected from the group consisting of ethane- 1,2-diamine, pentamethylene-l,5-diamine, hexamethylene- 1,6-diamine, l-amino-3,3,5-trimethyl-5-aminomethylcyclohexane (isophorone diamine), 1,4-diaminocyclohexane and bis(4-aminocyclohexyl)methane.

[0123] Clause 4. The use of any of clauses 1 to 3, characterized in that the content of nitrogen compounds in the aqueous polyurethane-polyurea dispersion before the addition or use of the at least one organic dialkyl dicarbonate is in the range from 0.0001% by weight to 5% by weight, preferably from 0.01% by weight to 1% by weight, relative to the total weight of the aqueous polyurethane- polyurea dispersion as 100% by weight.

[0124] Clause 5. The use of any of clauses 1 to 4, characterized in that the content of nitrogen compounds in the aqueous polyurethane-polyurea dispersion 24 hours after the addition or use of the at least one organic dialkyl dicarbonate is reduced by more than 80% by weight, preferably more than 90% by weight, particularly preferably more than 95% by weight, yet more preferably more than 98% by weight, relative to the content of nitrogen compounds in the aqueous polyurethane- polyurea dispersion before the addition or use of the at least one organic dialkyl dicarbonate as 100% by weight. Clause 6. The use of any of clauses 1 to 5, characterized in that the aqueous polyurethanepolyurea dispersion contains at least one compound having a biocidal effect which is distinct from the organic dialkyl dicarbonate, wherein the at least one compound having a biocidal effect is preferably a bactericide, fungicide and / or algicide, particularly preferably at least one isothiazolinone, yet more preferably is selected from the group consisting of chloromethylisothiazolinone, methylisothiazolinone, benzisothiazolinone, octylisothiazolinone, butylbenzisothiazolinone, dichlorooctylisothiazolinone and / or mixtures of at least two thereof, yet more preferably is selected from the group consisting of 5-chloro-2-methylisothiazolinone / 2- methylisothiazolinone and / or mixtures thereof, wherein the at least one compound having a biocidal effect is preferably present in an amount of 1 to 1000 mg / kg relative to the total aqueous polyurethane-polyurea dispersion.

[0125] Clause 7. The use of any of clauses 1 to 6, characterized in that the at least one organic dialkyl dicarbonate is selected from the group consisting of dimethyl dicarbonate, diethyl dicarbonate, dipropyl dicarbonate, diisopropyl dicarbonate, methyl ethyl dicarbonate, di-tert-butyl dicarbonate, diisobutyl dicarbonate and / or mixtures of at least two thereof, preferably dimethyl dicarbonate, diethyl dicarbonate and / or a mixture thereof, and particularly preferably is dimethyl dicarbonate. Clause 8. The use of any of clauses 1 to 7, characterized in that the at least one polyurethane- polyurea is present in an amount of 5 to 64% by weight, preferably 30 to 60% by weight, particularly preferably 40 to 50% by weight, in each case relative to the total aqueous polyurethane-polyurea dispersion.

[0126] Clause 9. The use of any of clauses 1 to 8, characterized in that the aqueous polyurethane- polyurea dispersion contains additional components are present selected from binders, assistants and additives, fdlers, auxiliaries, levelling agents, reactive diluents, plasticizers, neutralizing agents, catalysts, auxiliary solvents, thickeners, additives, tackifiers and mixtures thereof.

[0127] Clause 10. The use of any of clauses 1 to 9, characterized in that the at least one polyurethane- polyurea was obtained or is obtainable by reacting the following synthesis components:

[0128] (a) at least one diol and / or polyol component,

[0129] (b) at least one di- and / or polyisocyanate component;

[0130] (c) at least one component comprising at least one hydrophilizing group;

[0131] (d) at least one mono-, di- and / or tri-amino-functional and / or hydroxyamino-functional compound; and

[0132] (e) optionally other isocyanate-reactive compounds, wherein the components (a), (b), (c), (d) and (e) are distinct.

[0133] Clause 11. Process for producing an aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds, comprising at least the steps of:

[0134] (A) providing an aqueous polyurethane-polyurea dispersion containing at least one polyurethane-polyurea and at least one nitrogen compound selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / or secondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol;

[0135] (B) treating the aqueous polyurethane-polyurea dispersion from step (A) with at least one organic dialkyl dicarbonate; to obtain an aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds.

[0136] Clause 12. The process of clause 11, characterized in that, after step (B), at least the following step (C) is carried out:

[0137] (C) production of articles, cosmetics, coatings, adhesive layers or adhesives from the aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds obtained in step (B).

[0138] Clause 13. The process of clause 11 or clause 12, characterized in that the amines have a molecular weight in the range from 31 to 500 g / mol, preferably from 31 to 250 g / mol.

[0139] Clause 14. The process of any of clauses 11 to 13, characterized in that the amines are primary amines, preferably selected from the group consisting of ethane- 1,2-diamine, pentamethylene-1,5- diamine, hexamethylene- 1,6-diamine, l-amino-3,3,5-trimethyl-5-aminomethylcyclohexane

[0140] (isophorone diamine), 1,4-diaminocyclohexane and bis(4-aminocyclohexyl)methane.

[0141] Clause 15. The process of any of clauses 11 to 14, characterized in that the content of nitrogen compounds in the aqueous polyurethane-polyurea dispersion before the addition or use of the at least one organic dialkyl dicarbonate is in the range from 0.0001% by weight to 5% by weight, preferably from 0.01% by weight to 1% by weight, relative to the total weight of the aqueous polyurethane- polyurea dispersion as 100% by weight.

[0142] Clause 16. The process of any of clauses 11 to 15, characterized in that the content of nitrogen compounds in the aqueous polyurethane-polyurea dispersion 24 hours after the addition or use of the at least one organic dialkyl dicarbonate is reduced by more than 80% by weight, preferably more than 90% by weight, particularly preferably more than 95% by weight, yet more preferably more than 98% by weight, relative to the content of nitrogen compounds in the aqueous polyurethane- polyurea dispersion before the addition or use of the at least one organic dialkyl dicarbonate as 100% by weight.

[0143] Clause 17. The process of any of clauses 11 to 16, characterized in that the aqueous polyurethane-polyurea dispersion contains at least one compound having a biocidal effect which is distinct from the organic dialkyl dicarbonate, wherein the at least one compound having a biocidal effect is preferably a bactericide, fungicide and / or algicide, particularly preferably at least one isothiazolinone, yet more preferably is selected from the group consisting of chloromethylisothiazolinone, methylisothiazolinone, benzisothiazolinone, octylisothiazolinone, butylbenzisothiazolinone, dichlorooctylisothiazolinone and / or mixtures of at least two thereof, yet more preferably is selected from the group consisting of 5-chloro-2-methylisothiazolinone / 2- methylisothiazolinone and / or mixtures thereof, wherein the at least one compound having a biocidal effect is preferably present in an amount of 1 to 1000 mg / kg relative to the total aqueous polyurethane-polyurea dispersion.

[0144] Clause 18. The process of any of clauses 11 to 17, characterized in that the at least one organic dialkyl dicarbonate is selected from the group consisting of dimethyl dicarbonate, diethyl dicarbonate, dipropyl dicarbonate, diisopropyl dicarbonate, methyl ethyl dicarbonate, di-tert-butyl dicarbonate, diisobutyl dicarbonate and / or mixtures of at least two thereof, preferably dimethyl dicarbonate, diethyl dicarbonate and / or a mixture thereof, and particularly preferably is dimethyl dicarbonate.

[0145] Clause 19. The process of any of clauses 11 to 18, characterized in that the at least one polyurethane-polyurea is present in an amount of 5 to 64% by weight, preferably 30 to 60% by weight, particularly preferably 40 to 50% by weight, in each case relative to the total aqueous polyurethane-polyurea dispersion.

[0146] Clause 20. The process of any of clauses 11 to 19, characterized in that the aqueous polyurethane-polyurea dispersion contains additional components are present selected from binders, assistants and additives, fdlers, auxiliaries, levelling agents, reactive diluents, plasticizers, neutralizing agents, catalysts, auxiliary solvents, thickeners, additives, tackifiers and mixtures thereof.

[0147] Clause 21. The process of any of clauses 11 to 20, characterized in that the at least one polyurethane-polyurea was obtained or is obtainable by reacting the following synthesis components:

[0148] (a) at least one diol and / or polyol component,

[0149] (b) at least one di- and / or polyisocyanate component;

[0150] (c) at least one component comprising at least one hydrophilizing group;

[0151] (d) at least one mono-, di- and / or tri-amino-functional and / or hydroxyamino-functional compound; and

[0152] (e) optionally other isocyanate-reactive compounds, wherein the components (a), (b), (c), (d) and (e) are distinct.

[0153] Clause 22. The process of any of clauses 11 to 21, characterized in that the at least one organic dialkyl dicarbonate is present in an amount of 0.001 g / kg to 100 g / kg, preferably from 0. 1 g / kg to 50 g / kg, particularly preferably from 0.1 g / kg to 20 g / kg, relative to the total aqueous polyurethane- polyurea dispersion.

[0154] Clause 23. Use according to any of clauses 1 to 10, characterized in that the at least one organic dialkyl dicarbonate is used in a process according to any of clauses 11 to 22 for reducing the content of nitrogen compounds in an aqueous polyurethane-polyurea dispersion.

[0155] Clause 24. Aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds, which is obtained or is obtainable by the process according to any of clauses 11 to 22. Clause 25. Article, cosmetic, coating, adhesive layer, coating formulation, adhesive formulation and / or cosmetic formulation containing at least the aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds according to clause 24. The present invention will now be elucidated using examples.

[0156] Experimental

[0157] Materials and sources

[0158] The polyurethane dispersions used (Baybond ® PU 406, Imgranil ® DLC-F) were obtained from Covestro Deutschland AG, Leverkusen, DE.

[0159] All other chemicals were obtained from Sigma-Aldrich Chemie GmbH, Taufkirchen, Germany, unless otherwise stated.

[0160] DMDC: Dimethyl dicarbonate

[0161] DEDC: Diethyl dicarbonate

[0162] HyHy: Hydrazine hydrate (7803-57-8, 64% hydrazine solution in water)

[0163] Preventol® D7 : Lanxess Deutschland GmbH, Cologne, DE

[0164] Unless otherwise stated, all percentages are percentages by weight (% by weight).

[0165] Unless otherwise stated, all procedures and analytical measurements were performed at a temperature of 23°C (room temperature).

[0166] Methods:

[0167] Method for determining the hydrazine content

[0168] The concentrations of free hydrazine are determined by UPLC-UV after derivatization with acetone.

[0169] Sample preparation

[0170] 0.5 g of sample, 6.0 g of water and 0.5 g of 10% CaC12 solution in water are mixed. After 2 hours of mixing, the solution is centrifuged. 1000 pl of the supernatant and 50 pl of acetone are combined in a 1.5 ml HPLC vial and mixed. This sample is used for injection into an HPLC system having an ACQUITY HSS T3 column (Waters Corporation, Milford, MA, USA). The system is calibrated using a corresponding analysis of a sample which has a known content of hydrazine.

[0171] Method for determining the ethylenediamine content

[0172] Ethylenediamine is determined by gas chromatography following extraction with diethyl ether. The carrier gas is helium and decane is used as internal reference. The signals are detected using a FID detector; the area ratios are evaluated and used to ascertain the ethylenediamine content. Examples:

[0173] Trial 1

[0174] A sample of the polyurethane dispersion Baybond® PU 406 (non-ionically hydrophilized PU dispersion with polyether backbone, Covestro Deutschland AG, Leverkusen, Germany) was admixed with about 2000 ppm of hydrazine hydrate (relative to the original dispersion) with stirring at room temperature and left to stand overnight. The mixture was then divided into 4 parts of 100 g each. The samples were stirred in a container with a magnetic stirrer bar and the following was added: a) 1.0 g of formaldehyde solution (32% in water) b) 1.0 g of glucose c) 1.0 g of dimethyl dicarbonate

[0175] Each mixture was stirred at room temperature for 5 hours. After another day at room temperature, about 24 hours after addition of the additives, the hydrazine content was analyzed. The analysis gave the following results:

[0176] [a) and b) are reference examples not according to the invention]

[0177] Evaluation: Formaldehyde and glucose did not lead to a substantial depletion of the hydrazine content in the sample. In contrast, dimethyl dicarbonate led to a significant reduction in the hydrazine content in the sample. Trial 2

[0178] A sample of the polyurethane dispersion Baybond® PU 406 (non-ionically hydrophilized PU dispersion with polyether backbone, Covestro Deutschland AG, Leverkusen, Germany) was admixed with about 700 ppm of hydrazine hydrate (relative to the original dispersion) with stirring at room temperature and left to stand overnight. The mixture was then divided into 3 parts of 100 g each. The samples were stirred in a container with a magnetic stirrer bar and the following was added: a) nothing b) 1.0 g of dimethyl dicarbonate c) 1.0 g of di-tert-butyl dicarbonate

[0179] Each mixture was stirred at room temperature for 5 hours. After another day at room temperature, about 24 hours after addition of the additives, the hydrazine content was analyzed.

[0180] The analysis gave the following results:

[0181] [a) is a reference example not according to the invention]

[0182] Evaluation: At a lower starting amount of hydrazine than in example 1, the addition of 1% dimethyl dicarbonate led to a reduction in the hydrazine content to below the detection limits of the methods used (sample b)). Di-tert-butyl dicarbonate also leads to a considerable reduction in the hydrazine content (sample c)).

[0183] Trial 3

[0184] A sample of the polyurethane dispersion Baybond PU 406 (non-ionically hydrophilized PU dispersion with polyether backbone, Covestro Deutschland AG, Leverkusen, Germany) was admixed with about 100 ppm of ethylenediamine (relative to the original dispersion) with stirring at room temperature and left to stand overnight. The mixture was then divided into 4 parts of 100 g each. The samples were stirred in a container with a magnetic stirrer bar and the following was added: a) nothing (reference) b) 0.1 g of dimethyl dicarbonate c) 1.0 g of dimethyl dicarbonate d) 5.0 g of dimethyl dicarbonate

[0185] Each mixture was stirred at room temperature for 5 hours. After another day at room temperature, about 24 hours after addition of the additives, the ethylenediamine content was analyzed.

[0186] The analysis gave the following results:

[0187] [a) is a reference example not according to the invention]

[0188] Evaluation: Even the addition of small amounts of dimethyl dicarbonate (see example b)) leads to a reduction in the ethylenediamine content to below the detection limits of the analytical techniques used.

[0189] Trial 4

[0190] A sample of the polyurethane dispersion Baybond PU 406 (non-ionically hydrophilized PU dispersion with polyether backbone, Covestro Deutschland AG, Leverkusen, Germany) was admixed with about 1100 ppm of ethylenediamine (relative to the original dispersion) with stirring at room temperature and left to stand overnight. The mixture was then divided into 4 parts of 100 g each. The samples were stirred in a container with a magnetic stirrer bar and the following was added: a) nothing (reference) b) 0.1 g of dimethyl dicarbonate c) 1.0 g of dimethyl dicarbonate d) 5.0 g of dimethyl dicarbonate

[0191] Each mixture was stirred at room temperature for 5 hours. After another day at room temperature, about 24 hours after addition of the additives, the ethylenediamine content was analyzed. The analysis gave the following results:

[0192] [a) is a reference example not according to the invention]

[0193] Evaluation: The addition of very small amounts of dimethyl dicarbonate (0.1%, see example b)) leads to a slight reduction in the ethylenediamine content. Compared to batch 2, in this case more than 70% free ethylenediamine is still detectable because of the significantly higher starting amount of ethylenediamine. However, the addition of 1% dimethyl dicarbonate already leads to a reduction in the ethylenediamine content to a value below the detection limits of the analytical techniques used.

[0194] Trial 5 A biocide-free sample of Impranil DLC-F (anionically hydrophilized PU dispersion with polycarbonate backbone, Covestro Deutschland AG, Leverkusen, Germany) was admixed with the substances in the following table with stirring at room temperature:

[0195] Each mixture was stirred at room temperature for 5 hours.

[0196] The next day, 0.1 g of Preventol D7 solution diluted to half with demineralized water was admixed with each sample, with stirring. After 2 weeks of storage at room temperature, analysis was performed on the chloromethylisothiazolinone content (CMIT content) using HPLC-MS. The analysis gave the following results:

[0197] [a) and d) are reference examples not according to the invention]

[0198] Evaluation: Mixing ethylenediamine with Preventol D7 in a PU dispersion led to a significant depletion in the content of the active ingredient CMIT (sample a)) compared to the reference sample d).

[0199] Adding a small amount of dimethyl dicarbonate (0.1% relative to the dispersion, see example b)) leads to a certain stabilization of the CMIT content, although ethylenediamine was also admixed with this sample beforehand. This demonstrates the partial deactivation of ethylenediamine with a small amount of DMDC.

[0200] Adding a larger amount of dimethyl dicarbonate (1.0% relative to the dispersion, see example c)) leads to a significant stabilization of the CMIT content, although ethylenediamine was also admixed with this sample beforehand. The DMDC content in this sample is in the same range as in sample d) which did not have ethylenediamine admixed therewith. It was thus found that the CMIT-depleting effect of ethylenediamine could be effectively suppressed by adding DMDC and the resulting reaction of the ethylenediamine with DMDC.

[0201] There were no noticeable changes to the polyurethane dispersions during and after the addition of the additives dimethyl dicarbonate and diethyl dicarbonate. Average particle size (measured by a Zetasizer, Malvern Panalytical Ltd, UK) and dispersion viscosity (Haake Viscotester iQ, Fisher Scientific GmbH, Schwerte, DE) do not change significantly, but rather only within the range of typical variations of the analytical methods, after addition of the additive dimethyl dicarbonate. Films of the dispersions were applied to glass plates (squeegee 210 pm slot width) and dried at 50°C for 1 hour and then at 120°C for 1 hour. There were no visually detectable differences in flow, film quality or the colour of the films after addition of the additive dimethyl dicarbonate compared to the films without addition of the additives.

Claims

Claims1. Use of at least one organic dialkyl dicarbonate for reducing the content of nitrogen compounds in an aqueous polyurethane-polyurea dispersion containing at least one polyurethane-polyurea and at least one nitrogen compound, wherein the nitrogen compound is selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / or secondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol.

2. The use according to claim 1, characterized in that the amines have a molecular weight in the range from 31 to 500 g / mol, preferably from 31 to 250 g / mol.

3. The use according to claim 1 or claim 2, characterized in that the amines are primary amines, preferably selected from the group consisting of ethane- 1,2-diamine, pentamethylene-1,5- diamine, hexamethylene- 1,6-diamine, l-amino-3,3,5-trimethyl-5-aminomethylcyclohexane (isophorone diamine), 1,4-diaminocyclohexane and bis(4-aminocyclohexyl)methane.

4. The use according to any of claims 1 to 3, characterized in that the aqueous polyurethane- polyurea dispersion contains at least one compound having a biocidal effect which is distinct from the organic dialkyl dicarbonate, wherein the at least one compound having a biocidal effect is preferably a bactericide, fungicide and / or algicide, particularly preferably at least one isothiazolinone, yet more preferably is selected from the group consisting of chloromethylisothiazolinone, methylisothiazolinone, benzisothiazolinone, octylisothiazolinone, butylbenzisothiazolinone, dichlorooctylisothiazolinone and / or mixtures of at least two thereof, yet more preferably is selected from the group consisting of 5-chloro- 2-methylisothiazolinone / 2 -methylisothiazolinone and / or mixtures thereof, wherein the at least one compound having a biocidal effect is preferably present in an amount of 1 to 1000 mg / kg relative to the total aqueous polyurethane-polyurea dispersion.

5. The use according to any of claims 1 to 4, characterized in that the at least one organic dialkyl dicarbonate is selected from the group consisting of dimethyl dicarbonate, diethyl dicarbonate, dipropyl dicarbonate, diisopropyl dicarbonate, methyl ethyl dicarbonate, di-tert-butyl dicarbonate, diisobutyl dicarbonate and / or mixtures of at least two thereof, preferably dimethyl dicarbonate, diethyl dicarbonate and / or a mixture thereof, and particularly preferably is dimethyl dicarbonate.

6. Process for producing an aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds, comprising at least the steps of:(A) providing an aqueous polyurethane-polyurea dispersion containing at least one polyurethane-polyurea and at least one nitrogen compound selected from hydrazine, amines and mixtures thereof, wherein the amines have at least one primary and / orsecondary amino group, no carbonyl groups and a molecular weight in the range from 31 to 1000 g / mol;(B) treating the aqueous polyurethane-polyurea dispersion from step (A) with at least one organic dialkyl dicarbonate; to obtain an aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds.

7. The process according to claim 6, characterized in that, after step (B), at least the following step (C) is carried out:(C) production of articles, cosmetics, coatings, adhesive layers or adhesives from the aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds obtained in step (B).

8. The process of claim 6 or claim 7, characterized in that the amines have a molecular weight in the range from 31 to 500 g / mol, preferably from 31 to 250 g / mol.

9. The process according to any of claims 6 to 8, characterized in that the amines are primary amines, preferably selected from the group consisting of ethane- 1,2-diamine, pentamethylene- 1,5-diamine, hexamethylene- 1,6-diamine, l-amino-3,3,5-trimethyl-5- aminomethylcyclohexane (isophorone diamine), 1,4-diaminocyclohexane and bis(4- aminocyclohexyl)methane .

10. The process according to any of claims 6 to 9, characterized in that the content of nitrogen compounds in the aqueous polyurethane-polyurea dispersion before the addition or use of the at least one organic dialkyl dicarbonate is in the range from 0.0001% by weight to 5% by weight, preferably from 0.01% by weight to 1% by weight, relative to the total weight of the aqueous polyurethane-polyurea dispersion as 100% by weight.

11. The process according to any of claims 6 to 10, characterized in that the content of nitrogen compounds in the aqueous polyurethane-polyurea dispersion 24 hours after the addition or use of the at least one organic dialkyl dicarbonate is reduced by more than 80% by weight, preferably more than 90% by weight, particularly preferably more than 95% by weight, yet more preferably more than 98% by weight, relative to the content of nitrogen compounds in the aqueous polyurethane-polyurea dispersion before the addition or use of the at least one organic dialkyl dicarbonate as 100% by weight.

12. The process according to any of claims 6 to 11 , characterized in that the aqueous polyurethane- polyurea dispersion contains at least one compound having a biocidal effect which is distinct from the organic dialkyl dicarbonate, wherein the at least one compound having a biocidal effect is preferably a bactericide, fungicide and / or algicide, particularly preferably at least one isothiazolinone, yet more preferably is selected from the group consisting ofchloromethylisothiazolinone, methylisothiazolinone, benzisothiazolinone, octylisothiazolinone, butylbenzisothiazolinone, dichlorooctylisothiazolinone and / or mixtures of at least two thereof, yet more preferably is selected from the group consisting of 5-chloro- 2-methylisothiazolinone / 2 -methylisothiazolinone and / or mixtures thereof, wherein the at least one compound having a biocidal effect is preferably present in an amount of 1 to 1000 mg / kg relative to the total aqueous polyurethane-polyurea dispersion.

13. The process according to any of claims 6 to 12, characterized in that the at least one organic dialkyl dicarbonate is selected from the group consisting of dimethyl dicarbonate, diethyl dicarbonate, dipropyl dicarbonate, diisopropyl dicarbonate, methyl ethyl dicarbonate, di-tert- butyl dicarbonate, diisobutyl dicarbonate and / or mixtures of at least two thereof, preferably dimethyl dicarbonate, diethyl dicarbonate and / or a mixture thereof, and particularly preferably is dimethyl dicarbonate.

14. The process according to any of claims 6 to 13, characterized in that the at least one polyurethane-polyurea is present in an amount of 5 to 64% by weight, preferably 30 to 60% by weight, particularly preferably 40 to 50% by weight, in each case relative to the total aqueous polyurethane-polyurea dispersion.

15. The process according to any of claims 6 to 14, characterized in that the at least one polyurethane-polyurea was obtained or is obtainable by reacting the following synthesis components:(a) at least one diol and / or polyol component,(b) at least one di- and / or polyisocyanate component;(c) at least one component comprising at least one hydrophilizing group;(d) at least one mono-, di- and / or tri -amino-functional and / or hydroxyamino-functional compound; and(e) optionally other isocyanate-reactive compounds, wherein the components (a), (b), (c), (d) and (e) are distinct.

16. The process according to any of claims 6 to 15, characterized in that the at least one organic dialkyl dicarbonate is present in an amount of 0.001 g / kg to 100 g / kg, preferably from 0. 1 g / kg to 50 g / kg, particularly preferably from 0.1 g / kg to 20 g / kg, relative to the total aqueous polyurethane-polyurea dispersion.

17. Aqueous polyurethane-polyurea dispersion having a reduced content of nitrogen compounds, which is obtained or is obtainable by the process according to any of claims 6 to 16.

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