EP3215548A1

EP3215548A1 - Novel polyurethane dispersions based on renewable raw materials

Info

Publication number: EP3215548A1
Application number: EP15794493.5A
Authority: EP
Inventors: Kathrin COHEN; Karl Haeberle; Helfried Scheidl; Henning WETTACH
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2014-11-03
Filing date: 2015-10-30
Publication date: 2017-09-13
Also published as: US20170335047A1; JP2018500402A; CN107108839A; WO2016071245A1; KR20170078832A

Abstract

A polyurethane dispersion PUD containing at least one polyurethane P based on at least one polyisocyanate and at least one polyester polyol PES. The polyester polyol PES is based on at least one multivalent alcohol A and at least one dicarboxylic acid D and at least one multivalent alcohol A and/or at least one dicarboxylic acid D is at least partly recovered from renewable raw materials.

Description

New polyurethane dispersions based on renewable raw materials

The present invention relates to polyurethane dispersions PUD comprising at least one polyurethane P based on at least one polyisocyanate and at least one polyester polyol PES, wherein the polyester polyol PES based on at least one polyhydric alcohol A and at least one dicarboxylic acid D, wherein at least one polyhydric alcohol A and / or at least one Dicarboxylic acid D was at least partially obtained from renewable raw materials.

Another object of the present invention are methods for the preparation of polyurethane dispersions PUD and their use.

Polymeric hydroxyl compounds such as polyester polyols react with isocyanates to form polyurethanes which, depending on their specific mechanical properties, find a wide variety of possible uses. In particular, polyester polyols are used because of their favorable properties for high-quality polyurethane products.

Polyurethanes obtained at least partially using renewable raw materials are known, for example, from WO 201 1/083000 A1, WO 2012/17391 1 A1 or WO 2010/031792 A1.

The use of natural raw materials is gaining in importance in the polymer industry as the starting materials may be more cost effective. On the market side, polyurethane products based on renewable raw materials and thus at least partial substitution of petrochemical raw materials are increasingly in demand.

Natural raw materials are in particular substances which are obtained by processing from plants or parts of plants (or even animals). Characteristic of raw materials from renewable sources is a significantly high proportion of the carbon isotope ¹⁴ C. By its determination, the proportion of renewable raw materials can be determined experimentally. Renewable resources differ from those obtained through chemical synthesis or petroleum processing in that they are less homogeneous. Their composition can vary considerably more. Fluctuations in the composition of natural resources depend, for example, on factors such as climate and region in which the plant grows, season of harvest, variations between biological species and subspecies and the type of extraction process used in extraction (extrusion, centrifugation, filtration, distillation , Cutting, pressing, etc.). These variations in the composition of natural raw materials and the presence of further, difficult to separate However, lubricants, such as degradation products or impurities, often cause problems in subsequent processing and therefore limit the industrial benefits of these materials. The production of polyurethane dispersions from renewable resources is of great interest for ecological reasons.

One object of the present invention was to provide polyurethane dispersions using renewable raw materials whose performance properties are at least equivalent to those of polyurethane dispersions based on petrochemical raw materials.

According to the invention, this object has been achieved by polyurethane dispersions PUD comprising at least one polyurethane P based on at least one polyisocyanate and at least one polyester polyol PES, wherein the polyester polyol PES based on at least one polyhydric alcohol A and at least one dicarboxylic acid D, wherein at least one polyhydric alcohol A and / or at least one dicarboxylic acid D was at least partially obtained from renewable raw materials. The expression "wherein at least one polyhydric alcohol A and / or at least one dicarboxylic acid D was obtained at least partially from renewable raw materials" means that either at least one polyhydric alcohol A or at least one dicarboxylic acid D or at least one polyhydric alcohol A and at least one dicarboxylic acid D If polyesterol PES is based on more than one polyhydric alcohol A or more than one dicarboxylic acid D, then at least one of the polyhydric alcohol A and / or at least one of the dicarboxylic acids D should be obtained at least partially from renewable raw materials It is therefore possible, for example, that polyesterol PES is based on a polyhydric alcohol A, at least partly derived from renewable raw materials, and another entirely fully petrochemically produced polyhydric alcohol A.

It is also possible, for example, for polyesterol PES to be based on a dicarboxylic acid D which has been obtained, at least in part, from renewable raw materials and another, completely petrochemically produced dicarboxylic acid D.

The term "based" or "based on" in the context of this application means "made from", the following components not being an exhaustive list.

Polyurethane dispersions PUD according to the invention are generally aqueous. Polyurethane dispersions PUD contain at least one polyurethane P. Polyurethane dispersions PUD generally contain from 10 to 75% by weight of polyurethane, based on the dispersion. In a preferred embodiment, polyurethane dispersions comprise PUD polyurethanes P which have been prepared by the prepolymer mixing process, in particular those prepared by the process according to the invention for the preparation of polyurethane dispersions PUD described below.

Aqueous polyurethane dispersions PUD generally contain 90 to 25% by weight of water, based on the dispersion.

At least one polyester polyol PES is used to prepare the polyurethanes P, the polyester polyol PES being based on at least one polyhydric alcohol A and at least one dicarboxylic acid D, the at least one polyhydric alcohol A and / or the at least one dicarboxylic acid D being obtained at least partially from renewable raw materials has been.

Proof that a feedstock was derived from renewable raw materials is, for example, according to ASTMD6866 14C method possible. For the purposes of this invention, a feedstock is to be considered as "obtained from renewable raw materials" if the amount of carbon-14 (C-14) it contains in about (with a maximum deviation of 6%) corresponds to the content of ASTM D6866 on C -14 in atmospheric C02.

The content of C-14 in a material can be determined by determining the decays of C-14 in that material by liquid scintillation. Preferably, such raw materials are considered to be derived from renewable resources if they contain an amount of C-14 having a radioactive decay of at least 1.5 dpm / gC (decays per minute per gram of carbon), preferably 2 dpm / gC, more preferably 2.5 dpm / gC and most preferably 5 dpm / gC.

The polyester polyols used PES according to the invention preferably have an average functionality in the range of 1, 8 to 2.3, preferably in the range of 1, 9 to 2.2, in particular of 2. Preferably, the polyester polyol PES is a polyester diol. Accordingly, according to a further embodiment, the present invention relates to polyurethane dispersions PUD comprising a polyurethane P based on at least one polyisocyanate and at least one polyester diol, the polyester diol being based on at least one polyhydric alcohol A and at least one dicarboxylic acid D, where at least one polyhydric alcohol A and / or at least one dicarboxylic acid D was at least partially obtained from renewable raw materials. Suitable molecular weight ranges for the polyester polyols PES used according to the invention are known per se to the person skilled in the art. According to a preferred embodiment, the molecular weight of the polyester polyol PES is in the range of 500 to 4000 g / mol, more preferably in the range of 800 and 3000 g / mol and most preferably in the range of 1000 and 2500 g / mol.

Particularly suitable polyester polyols PES according to the invention have an OH number in the range from 25 to 230 mg KOH / g, particularly preferably in the range from 35 to 140 mg KOH / g and very particularly preferably in the range from 40 to 15 mg KOH / g ( KOH number determined according to DIN 53240).

According to the invention, the polyesterpolyol PES is based on at least one polyhydric alcohol A. Suitable polyhydric alcohols A are, for example, polyhydric aliphatic alcohols, for example aliphatic alcohols having 2, 3, 4 or more OH groups, for example 2 or 3 OH groups. Aliphatic alcohols which are suitable according to the invention are, for example, C 2 - to C 12 -alcohols, preferably C 2 - to C 8 -alcohols and very particularly preferably C 2 - to C 6 -alcohols. According to the invention, the at least one polyhydric alcohol A is preferably a diol, suitable diols being known per se to a person skilled in the art.

Suitable aliphatic C 2 - to C 6 -diols are, for example, ethylene glycol, diethylglycol, 3-oxapentane-1, 5-diol, 1, 3-propanediol, 1, 2-propanediol, dipropylene glycol, 1, 4-butanediol, 1, 5 Pentanediol, 1, 6-hexanediol, 2-methyl-1, 3-propanediol and 3-methyl-1, 5-pentanediol. More preferably, the at least one polyhydric alcohol A selected from the group consisting of 1, 3-propanediol and 1, 4-butanediol.

According to a further embodiment, the present invention also relates to polyurethane dispersions PUD comprising at least one polyurethane P, wherein the at least one polyhydric alcohol A is selected from the group consisting of aliphatic C 2 to C 6 diols.

According to a further embodiment, the present invention also relates to polyurethane dispersions PUD comprising at least one polyurethane P, wherein the at least one polyhydric alcohol A is selected from the group consisting of 1, 3-propanediol and 1, 4-butanediol.

In one embodiment, polyesterols PES based on at least one polyhydric alcohol A, wherein at least one alcohol A was at least partially recovered from renewable resources. It is possible that the polyhydric alcohol A was partially or completely recovered from renewable resources. According to the invention it is also possible that a mixture of two or more polyvalent Alcohol A is used. If a mixture of two or more polyhydric alcohols A is used, at least one of the polyhydric alcohols A used can be obtained at least partially from renewable raw materials. Suitable alcohols A, which can be obtained at least partly from renewable raw materials, are, for example, 1,3-propanediol, 1,4-butanediol, ethylene glycol, isosorbide, furandimethanol and tetrahydrofuran dimethanol.

The 1,3-propanediol may accordingly be synthetically produced 1,3-propanediol, but in particular 1,3-propanediol from renewable raw materials ("bio-1,3-propanediol"). Bio-1, 3-propanediol can be obtained for example from corn and / or sugar. Another possibility is the conversion of glycerine waste from biodiesel production. According to a further preferred embodiment of the invention, the at least one polyhydric alcohol A is 1,3-propanediol which has at least partly been obtained from renewable raw materials.

According to a further embodiment, the present invention also relates to polyurethane dispersions PUD comprising at least one polyurethane P, wherein the at least one polyhydric alcohol A 1, 3-propanediol, which was obtained at least partially from renewable raw materials.

To increase the functionality of the polyester polyols PES, it is also possible to use trifunctional or higher alcohols A as structural components. Examples of these are glycerol, trimethylolpropane and pentaerythritol. It is also possible to use oligomeric or polymeric products having at least two hydroxyl groups. Examples of these are polytetrahydrofuran, polylactones, polyglycerol, polyetherols, polyesterol or α, ω-dihydroxypolybutadiene.

In one embodiment, polyester polyol PES is based in addition to at least one polyhydric alcohol A on at least one dicarboxylic acid D, wherein at least one dicarboxylic acid D was at least partially obtained from renewable raw materials. Suitable dicarboxylic acids D for the preparation of polyester polyols are known per se to the person skilled in the art. In one embodiment, a mixture of at least two dicarboxylic acids D is used, for example a mixture of two, three or 4 dicarboxylic acids D. For example, in the context of the present invention, a mixture of two or three different dicarboxylic acids D selected from the group of C2 - Act to C12 dicarboxylic acids. C2 to C12 dicarboxylic acids are understood to mean dicarboxylic acids which are aliphatic or branched, and two to twelve carbon atoms. have lenstoffatome. It is also possible that dicarboxylic acids D used according to the invention are selected from C 2 - to C 14 -dicarboxylic acids, preferably C 4 - to C 12 -dicarboxylic acids and particularly preferably to C 6 - to C 10 -dicarboxylic acids. In one embodiment, one or more of the dicarboxylic acids D used is also present as carbonic acid diester or as carboxylic acid anhydride. As dicarboxylic acid D can in principle be used aliphatic and / or aromatic dicarboxylic acids. In one embodiment, a mixture of at least two dicarboxylic acids D is used, wherein at least one of the at least two dicarboxylic acids D was at least partially obtained from renewable raw materials. In the context of the present invention, the mixture used may also contain 3 or more dicarboxylic acids D, at least one of the dicarboxylic acids D present being obtained at least partially from renewable raw materials. According to one embodiment of the present invention, the mixture used consists of two dicarboxylic acids D, wherein at least one of the two dicarboxylic acids D was at least partially obtained from renewable raw materials. Suitable dicarboxylic acids D can be obtained from natural raw materials by special treatment processes. Thus, for example, by treating castor oil with sodium or potassium hydroxide at high temperatures in the presence of relatively long-chain alcohols (such as 1- or 2-octanol) sebacic acid in a purity of> 99.5% can be obtained, depending on the reaction conditions. Sebacic acid (1,8-octanedicarboxylic acid) belongs to the homologous series of aliphatic dicarboxylic acids. In addition to sebacic acid, succinic acid and / or 2-methyl-succinic acid are also particularly suitable according to the invention. These can be obtained, for example, from natural raw materials such as sugar or maize by fermentation. Another dicarboxylic acid D which is suitable according to the invention is azelaic acid, which was obtained at least partly from renewable raw materials. Another dicarboxylic acid D which is suitable according to the invention is furandicarboxylic acid which has at least partly been obtained from renewable raw materials. Another dicarboxylic acid D which is suitable according to the invention is tetrahydrofurandicarboxylic acid, which has at least partly been obtained from renewable raw materials

In a particularly preferred embodiment of the invention, the dicarboxylic acid D obtained at least in part from natural raw materials is selected from the group consisting of sebacic acid, azelaic acid, dodecanedioic acid and succinic acid. In a further preferred embodiment of the invention, the mixture used comprises sebacic acid obtained from renewable raw materials.

In a further preferred embodiment of the invention, the mixture used contains azelaic acid obtained from renewable raw materials.

According to a further embodiment, the present invention also relates to polyurethane dispersions PUD containing at least one polyurethane P, which is based on sebacic acid, which was obtained at least partially from renewable raw materials.

According to a further embodiment, the present invention also relates to polyurethane dispersions PUD comprising at least one polyurethane P, which is based on azelaic acid, which was obtained at least partially from renewable raw materials. Also optionally in addition to a dicarboxylic acid D, which was obtained at least partially from renewable raw materials, other dicarboxylic acids used D, are preferably selected from the group of C2 to C12 dicarboxylic acids. Suitable are the aforementioned dicarboxylic acids and especially adipic acid. According to a further embodiment, the present invention also relates to polyurethane dispersions PUD comprising at least one polyurethane P, based on a mixture of at least two dicarboxylic acids D comprising sebacic acid, which was obtained at least partially from renewable raw materials, and adipic acid.

According to a further embodiment, the present invention also relates to polyurethane dispersions PUD comprising at least one polyurethane P, based on a mixture of at least two dicarboxylic acids D comprising azelaic acid, which was obtained at least partially from renewable raw materials, and adipic acid.

In one embodiment, it is also possible that in addition to sebacic acid, which was obtained at least partially from renewable raw materials, at least one further dicarboxylic acid D is contained in the mixture, which is based at least partially on renewable raw materials. Accordingly, according to another embodiment of the present invention, the mixture contains two dicarboxylic acids D, both of which are at least partially obtained from renewable raw materials. For example, the mixture of at least two dicarboxylic acids D may contain at least sebacic acid and adipic acid, wherein it is also possible that sebacic acid and adipic acid were each at least partially obtained from renewable raw materials.

Preferably, the mixture of at least two dicarboxylic acids D to at least 90 wt .-% of sebacic acid and adipic acid, more preferably 95 to 100 wt .-%, in particular from 98 to 99.99 wt .-%.

The mixture of at least two dicarboxylic acids D preferably comprises at least 90% by weight of azelaic acid and adipic acid, more preferably from 95 to 100% by weight, in particular from 98 to 99.99% by weight.

The mixing ratio of the dicarboxylic acids D used in the mixture can vary within wide limits. In this case, the mixing ratio of at least two dicarboxylic acids D in mol% in a preferred embodiment in the range of 90:10 to 10:90, more preferably in the range of 80:20 to 20:80, particularly preferably in the range of 70:30 to 30 : 70 vary.

According to a further preferred embodiment, the mixing ratio of the dicarboxylic acids D sebacic acid to adipic acid in mol% in the range of 90:10 to 10:90, more preferably in the range of 80:20 to 20:80, particularly preferably in the range of 70: 30 to 30:70.

According to a further preferred embodiment, the mixing ratio of the dicarboxylic acids D azelaic acid to adipic acid in mol% in the range of 90:10 to 10:90, more preferably in the range of 80:20 to 20:80, particularly preferably in the range of 70:30 to 30:70.

In one embodiment, the at least used dicarboxylic acid D and preferably also the polyhydric alcohol A used is preferably obtained at least partially from renewable raw materials. At least partially means within the scope of the present invention that at least 25% of the corresponding dicarboxylic acid D or alcohol A has been obtained from renewable raw materials, in particular that it has been obtained from 50 to 100% renewable raw materials, preferably from 75 to 100%. , more preferably from 85 to 100%, especially preferably from 95 to 100%.

According to a further embodiment of the present invention, at least one dicarboxylic acid D and at least one polyhydric alcohol A are used for the preparation of the polyester polyols PES, which have each been obtained at least partially from renewable raw materials. Process for the preparation of polyester polyols PES by polycondensation of the corresponding hydroxy compounds with dicarboxylic acids D preferably at elevated temperature and reduced pressure, preferably in the presence of known catalysts are well known and widely described.

Methods of making polyurethanes P are also well known. For example, polyurethanes P can be prepared by reacting isocyanates with polyester polyol and optionally chain extenders having a molecular weight of from 50 to 499 g / mol, if appropriate in the presence of catalysts and / or customary auxiliaries.

In principle, the ratio of the components used can vary within wide ranges. The ratio of the components used is usually described by the ratio of the NCO groups to the OH groups, where the OH groups is the sum of the OH groups of the polyesterpolyol used PES, chain extender and optionally further additives.

According to the invention, the ratio of NCO to OH groups is, for example, in the range from 0.9 to 1.1, preferably in the range from 0.95 to 1.05. According to the invention, the preparation of polyurethanes P by reacting the isocyanate with the polyester polyol PES and optionally other isocyanate-reactive compounds and optionally chain extenders optionally in the presence of catalysts and / or conventional auxiliaries. The preparation of the polyurethane P can also be carried out via the intermediate stage of prepolymers.

Suitable organic isocyanates are the polyisocyanates customarily used in polyurethane dispersion chemistry, for example aliphatic, aromatic and cycloaliphatic di- and polyisocyanates, the aliphatic hydrocarbon radicals having, for example, 4 to 12 carbon atoms and the cycloaliphatic or aromatic hydrocarbon radicals, for example 6 to 15 carbon atoms or the araliphatic Hydrocarbon radicals have for example 7 to 15 carbon atoms, with an NCO functionality of at least 1, 8, preferably 1, 8 to 5 and particularly preferably 2 to 4, and their isocyanurates, biurets, allophanates and uretdiones.

The diisocyanates are preferably isocyanates having 4 to 20 C atoms. Examples of customary diisocyanates are aliphatic diisocyanates, such as tetramethylene diisocyanate, hexamethylene diisocyanate (1,6-diisocyanatohexane), octamethylene diiso- cyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, esters of lysine diisocyanate, tetramethylxylylene diisocyanate, trimethylhexane diisocyanate or tetramethylhexane diisocyanate, cycloaliphatic diisocyanates such as 1,4-, 1,3- or 1,2-diisocyanatocyclohexane, the trans / trans, the cis / cis and the cis / trans isomers of 4,4'- or 2,4'-di (isocyanatocyclohexyl) methane, 1-isocyanato-3,3,5-trimethyl-5- (isocyanatomethyl) cyclohexane (isophorone diisocyanate), 2 , 2-bis (4-isocyanatocyclohexyl) propane, 1, 3- or 1, 4-bis (isocyanatomethyl) cyclohexane or 2,4- or 2,6-diisocyanato-1-methylcyclohexane and aromatic diisocyanates such as 2 , 4- or 2,6-toluene diisocyanate and mixtures thereof, m- or p-xylylene diisocyanate, 2,4'- or 4,4'-diisocyanatodiphenylmethane and mixtures thereof, 1, 3- or 1, 4-phenylene diisocyanate, 1 -Chloro-2,4-phenylene diisocyanate, 1,5-naphthylene diisocyanate, diphenylene-4,4'-diisocyanate, 4,4'-diisocyanato-3,3'-dimethyldiphenyl, 3-methyl diphenylmethane-4,4'-diisocyanate, 1,4-diisocyanatobenzene or diphenyl ether-4,4'-diisocyanate. There may also be mixtures of said diisocyanates.

Preference is given to aliphatic and cycloaliphatic diisocyanates, particular preference being given to isophorone diisocyanate, hexamethylene diisocyanate, meta-tetramethylxylylene diisocyanate (m-TMXDI) and 1,1-methylenebis [4-isocyanato] cyclohexane (H12MDI).

Suitable polyisocyanates are polyisocyanates containing isocyanurate groups, uretdione diisocyanates, polyisocyanates containing biuret groups, polyisocyanates containing urethane or allophanate groups, polyisocyanates containing oxadiazinetrione groups, uretonimine-modified polyisocyanates of straight-chain or branched C 4 -C 20 -alkylene diisocyanates, cycloaliphatic diisocyanates having a total of from 6 to

20 C atoms or aromatic diisocyanates having a total of 8 to 20 carbon atoms or mixtures thereof.

The usable di- and polyisocyanates preferably have a content of isocyanate groups (calculated as NCO, equivalent weight = 42 g / mol) of 10 to 60 wt .-% based on the diisocyanate and polyisocyanate (mixture), preferably 15 to 60 wt .-% and particularly preferably 20 to 55 wt .-%.

Preferred are aliphatic or cycloaliphatic di- and polyisocyanates, e.g. the abovementioned aliphatic or cycloaliphatic diisocyanates, or mixtures thereof.

Also preferred are 1) isocyanurate-containing polyisocyanates of aromatic, aliphatic and / or cycloaliphatic diisocyanates. Particularly preferred in this case the corresponding aliphatic and / or cycloaliphatic isocyanato isocyanurates and in particular those based on hexamethylene diisocyanate and isophorone diisocyanate. The isocyanurates present are, in particular, tris-isocyanatoalkyl- or tris-isocyanato-cycloalkyl isocyanurates, which are cyclic trimers of the diisocyanates, or mixtures with their higher homologs containing more than one isocyanurate ring. The isocyanato-isocyanurates generally have an NCO content of 10 to 30 wt .-%, in particular 15 to 25 wt .-% and an average NCO functionality of 3 to 4.5.

Uretdione diisocyanates having aromatic, aliphatic and / or cycloaliphatic bonded isocyanate groups, preferably aliphatically and / or cycloaliphatically bonded and in particular those derived from hexamethylene diisocyanate or isophorone diisocyanate. Uretdione diisocyanates are cyclic dimerization products of diisocyanates.

The uretdione diisocyanates can be used in the preparations as the sole component or in a mixture with other polyisocyanates, in particular those mentioned under 1). Biuret group-containing polyisocyanates having aromatic, cycloaliphatic or aliphatic bound, preferably cycloaliphatic or aliphatic bound isocyanate groups, in particular tris (6-isocyanatohexyl) biuret or mixtures thereof with its higher homologs. These biuret polyisocyanates generally have an NCO content of 18 to 22 wt .-% and an average NCO functionality of 3 to 4.5.

Urethane and / or allophanate groups containing polyisocyanates having aromatically, aliphatically or cycloaliphatically bonded, preferably aliphatically or cycloaliphatically bonded isocyanate groups, as for example by reacting excess amounts of hexamethylene diisocyanate or isophorone diisocyanate with polyhydric alcohols such. Trimethylolpropane, neopentyl glycol, pentaerythritol, 1, 4-butanediol, 1, 6-hexanediol, 1, 3-propanediol, ethylene glycol, diethylene glycol, glycerol, 1, 2-dihydroxypropane or mixtures thereof can be obtained. These urethane and / or allophanate-containing polyisocyanates generally have an NCO content of 12 to 20 wt .-% and an average NCO functionality of 2.5 to 3.

Oxadiazinetrione-containing polyisocyanates, preferably derived from hexamethylene diisocyanate or isophorone diisocyanate. Such oxadiazinetrione-containing polyisocyanates can be prepared from diisocyanate and carbon dioxide. 6) Uretonimine-modified polyisocyanates.

The polyisocyanates 1) to 6) can be used in a mixture, if appropriate also in a mixture with diisocyanates.

Particularly suitable mixtures of these isocyanates are the mixtures of the respective structural isomers of diisocyanatotoluene and diisocyanatodiphenylmethane; in particular, the mixture of 20 mol% of 2,4-diisocyanatotoluene and 80 mol% of 2,6-diisocyanatotoluene is suitable. Furthermore, the mixtures of aromatic isocyanates such as 2,4-diisocyanatotoluene and / or 2,6-diisocyanatotoluene with aliphatic or cycloaliphatic isocyanates such as hexamethylene diisocyanate or IPDI are particularly advantageous, the preferred mixing ratio of the aliphatic to aromatic isocyanates being 4: 1 to 1: 4 is.

As compounds (a) it is also possible to use isocyanates which, in addition to the free isocyanate groups, contain further blocked isocyanate groups, e.g. Wear uretdione or urethane troops. Optionally, it is also possible to use those isocyanates which have only one

Wear isocyanate group. In general, their proportion is at most 10 mol%, based on the total molar amount of the monomers. The monoisocyanates usually carry further functional groups such as olefinic groups or carbonyl groups and serve to introduce functional groups into the polyurethane, which make possible the dispersion or crosslinking or further polymer-analogous reaction of the polyurethane. Suitable for this purpose are monomers such as isopropenyl-α, α-dimethylbenzyl isocyanate (TMI).

As chain extenders it is possible to use generally known aliphatic, araliphatic, aromatic and / or cycloaliphatic compounds having a molecular weight of 50 to 499 g / mol, preferably 2-functional compounds, for example alkanediols having 2 to 10 C atoms in the alkylene radical, preferably butanediol 1, 4, hexanediol-1, 6 and / or di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona- and / or decalcylene glycols having 3 to 8 carbon atoms, preferably unbranched alkanediols, in particular propane-1, 3-diol and butane-1, 4-diol.

In one embodiment, the chain extender is selected from the group consisting of aliphatic C2-C6 diols, more preferably selected from the group consisting of 1, 3-propanediol, 1, 4-butanediol and 1, 6-hexanediol. According to a further embodiment, the present invention also relates to polyurethane dispersions PUD comprising at least one polyurethane P as described above, wherein the at least one chain extender is selected from the group consisting of C2 to C6 diols.

According to the invention, it is further preferred that the chain extender used was obtained at least partially from renewable raw materials. According to the invention, it is possible that the chain extender used was obtained partially or completely from renewable raw materials.

According to one embodiment, the chain extender is accordingly selected from the group consisting of 1, 3-propanediol and 1, 3-propanediol, which was obtained at least partially from renewable raw materials. According to a further embodiment, the at least one dicarboxylic acid D and the at least one polyhydric alcohol A used for preparing the polyesterpolyols PES and the chain extender used are each at least partially obtained from renewable raw materials. Furthermore, amines carrying more than 2 isocyanate-reactive amino groups are suitable chain extenders. Preferred amines as chain extenders are polyfunctional amines of the molecular weight range from 32 to 500 g / mol, preferably from 60 to 300 g / mol, which contain at least two primary, two secondary or at least one primary and one secondary amino group. Examples of these are diamines such as diaminoethane, diaminopropanes, diaminobutanes, diaminohexanes, piperazine, 2,5-dimethylpiperazine, amino-3-aminomethyl-3,5,5-trimethylcyclohexane (isophoronediamine, IPDA), 4,4 ' Diaminodicyclohexylmethane, 1,4-diaminocyclohexane, aminoethanolamine, hydrazine, hydrazine hydrate or triamines such as diethylenetriamine or 1,8-diamino-4-aminomethyloctane or higher amines such as triethylenetetramine, tetraethylenepentamine or polymeric amines such as polyethyleneamines, hydrogenated polyacrylic nitrile or at least partially hydrolyzed poly-N-vinylformamide each having a molecular weight up to 2000, preferably up to 1000 g / mol.

The amines can also be used in blocked form, for example in the form of the corresponding ketimines (see, for example, CA-1 129 128), ketazines (cf., for example, US Pat. No. 4,269,748) or amine salts (see US Pat. No. 4,292,226) become. Oxazolidines, as used for example in US Pat. No. 4,192,937, also represent blocked polyamines which can be used for the preparation of the polyurethanes for chain extension of the prepolymers. When using such capped polyamines they are generally mixed with the prepolymers in the absence of water and these Mixture then mixed with the dispersion water or a portion of the dispersion water, so that hydrolytically the corresponding polyamines are released. Preference is given to using mixtures of di- and triamines, more preferably mixtures of isophoronediamine and diethylenetriamine.

According to one embodiment, the present invention also relates to polyurethane dispersions PUD comprising at least one polyurethane P as described above, wherein the at least one chain extender is selected from the group of amines which carry more than 2 isocyanate-reactive amino groups.

Suitable catalysts which in particular accelerate the reaction between the NCO groups of the polyisocyanates and the polyol component, are those according to

Prior art known and customary compounds and the literature can be found. Suitable catalysts in the context of the present invention are, for example, tertiary amines, such as. For example, triethylamine, dimethylcyclohexylamine, N-methylmorpholine, N, N'-dimethylpiperazine, 2- (dimethylaminoethoxy) ethanol, diazabicyclo- (2,2,2) - octane and the like and in particular organic metal compounds such as titanic acid esters, iron compounds such , For example, iron (III) acetylacetonate, tin compounds, e.g. As tin diacetate, tin dioctoate, tin dilaurate or Zinndialkylsalze aliphatic carboxylic acids such as dibutyltin diacetate, dibutyltin dilaurate or the like. The catalysts are usually used in amounts of 0.00001 to 0.1 parts by weight per 100 parts by weight of polyhydroxyl compound.

In addition to catalysts, the constituent components, i. the polyols, isocyanates and chain extenders, also common auxiliaries are added. Examples include surfactants, flame retardants, nucleating agents, lubricants and mold release agents, dyes and pigments, stabilizers, eg. B. against

Hydrolysis, light, heat or discoloration, inorganic and / or organic fillers, reinforcing agents, and metal deactivators .. In order to stabilize the polyurethane according to the invention against aging, stabilizers are preferably added to the polyurethane. Stabilizers in the context of the present invention are additives which protect a plastic or a plastic mixture against harmful environmental influences. Examples are primary and secondary antioxidants, thiosynergists, trivalent phosphorus organophosphorus compounds, hindered amine light stabilizers, UV absorbers, hydrolysis inhibitors, quenchers and flame retardants. Examples of commercial stabilizers are given in Plastics Additive Handbook, 5th Edition, H. Zweifel, ed., Hanser Publishers, Munich, 2001, p.98-S136. Is the invention exposed to polyurethane during its application thermo-oxidative damage, antioxidants can be added. Preferably, phenolic antioxidants are used. Examples of phenolic antioxidants are given in Plastics Additive Handbook, 5th edition, H. Zweifel, ed, Hanser Publishers, Munich, 2001, p.98-107 and S166-S. 121. Preference is given to those phenolic antioxidants whose molecular weight is greater than 700 g / mol. An example of a preferred phenolic antioxidant is pentaerythrityl tetrakis (3- (3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl) propionate) (Irganox®1010) or other high molecular weight condensation products of corresponding antioxidants. The phenolic antioxidants are generally used in concentrations between 0.1 and 5 wt .-%, preferably between 0.1 and 2 wt .-%, in particular between 0.5 and 1, 5 wt .-%, each based on the Total weight of the polyurethane. Furthermore, antioxidants are preferably used which are amorphous or liquid. Even if the polyurethanes according to the invention are significantly more stable to ultraviolet radiation than z. B. with phthalates or benzoates plasticized polyurethanes, stabilization containing only phenolic stabilizers is often not sufficient. For this reason, the polyurethanes according to the invention which are exposed to UV light are preferably additionally stabilized with a UV absorber. UV absorbers are molecules that absorb high-energy UV light and dissipate energy. Common UV absorbers which are used in the art include, for. B. to the group of cinnamic acid esters, the Diphenylcyanacrylate, the Oxalsäureamide (oxanilides), in particular 2-ethoxy-2'-ethyloxanilid, the formaminedines, the Benzylidenemalonate, the Diarylbutadiene, triazines and benzotriazoles. Examples of commercial UV absorbers can be found in Plastics Additive Handbook, 5th edition, H. Zweifel, ed, Hanser Publishers, Munich, 2001, page 1 16-122. In a preferred embodiment, the UV absorbers have a number average molecular weight of greater than 300 g / mol, in particular greater than 390 g / mol. Furthermore, the UV absorbers preferably used should have a molecular weight of not greater than 5000 g / mol, particularly preferably not greater than 2000 g / mol. Particularly suitable as a UV absorber is the group of benzotriazoles. Examples of particularly suitable benzotriazoles are Tinuvin®213, Tinuvin®328, Tinuvin®571, as well as Tinuvin® 384 and Eversorb® 82. The UV absorbers are preferred in amounts between 0.01 and 5% by weight, based on the Total weight of polyurethane metered, more preferably between 0.1 and 2.0 wt .-%, in particular between 0.2 and 0.5 wt .-%, each based on the total weight of the polyurethane. Often, a UV stabilization described above based on an antioxidant and a UV absorber is still not sufficient to ensure good stability of the polyurethane according to the invention against the harmful influence of UV rays. In this case, it is preferable to add, in addition to the antioxidant and the UV absorber, a hindered amine light stabilizer (HALS). A particularly preferred UV stabilization comprises a mixture of a phenolic stabilizer, a benzotriazole and a HALS compound in the preferred amounts described above. However, it is also possible to use compounds which combine the functional groups of the stabilizers, for example sterically hindered piperidylhydroxybenzyl condensation products such as, for example, di (1, 2,2,6,6-pentamethyl-4-piperidyl) -2-butyl -2- (3,5-di-tert-butyl-4-hydroxybenzyl) malonates, Tinuvin®144.

A further subject of the invention are processes for the preparation of polyurethane dispersions PUD comprising the reaction of at least one polyisocyanate with at least one polyester polyol PES, where the polyester polyol is based on at least one polyhydric alcohol A and at least one dicarboxylic acid D, where at least one polyhydric alcohol A and / or at least one dicarboxylic acid D was at least partially obtained from renewable raw materials.

Another object of the present invention is a process for the preparation of aqueous polyurethane dispersions PUD, wherein the aqueous polyurethane dispersions are prepared as follows:

I. Preparation of a polyurethane by reacting a) at least one polyfunctional isocyanate having 4 to 30 carbon atoms, b) diols, of which b1) 10 to 100 mol%, based on the total amount of diols (b), molecular weight of 500 have up to 5000, and b2) 0 to 90 mol%, based on the total amount of diols (b), have a molecular weight of 60 to 500 g / mol, c) optionally further of the diols (b) different polyvalent compounds with reactive Groups which are alcoholic hydroxyl groups or primary or secondary amino groups; and d) monomers other than monomers (a), (b) and (c) having at least one isocyanate group or at least one opposite

Isocyanate groups reactive group, which also carry at least one hydrophilic group or a potentially hydrophilic group, whereby the water dispersibility of the polyurethanes is effected, to a polyurethane in the presence of a solvent S and II. subsequent dispersion of the polyurethane in water, III. wherein after or during step II optionally polyamines can be added, wherein diols b), preferably diol b1) comprise at least one polyester polyol PES based on at least one polyhydric alcohol A and at least one dicarboxylic acid D, wherein at least one polyhydric alcohol A and / or at least one dicarboxylic acid D was at least partially obtained from renewable raw materials.

Suitable solvents S are, for example, acetone, methyl ethyl ketone, N- (cyclo) alkylpyrrolidones, such as N-methylpyrrolidone (NMP), N-ethylpyrrolidone (NEP) or N-cyclohexylpyrrolidone; N-acylmorpholines, such as formylmorpholine or acetylmorpholione, dioxolanes, such as 1,3-dioxolane, tetrahydrofuran.

Suitable monomers in (a) are the polyisocyanates customarily used in polyurethane chemistry, for example aliphatic, aromatic and cycloaliphatic di- and polyisocyanates, the aliphatic hydrocarbon radicals having, for example, 4 to 12 carbon atoms and the cycloaliphatic or aromatic hydrocarbon radicals, for example 6 to 15 carbon atoms or the aliphatic hydrocarbon radicals have, for example, 7 to 15 carbon atoms, with an NCO functionality of at least 1.8, preferably 1.8 to 5 and particularly preferably 2 to 4 in question, and also their isocyanurates, biurets, allophanates and uretisdins.

The diisocyanates are preferably isocyanates having 4 to 20 C atoms. Examples of customary diisocyanates are aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate (1,6-diisocyanatohexane), octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, esters of lysine diisocyanate, tetramethylxylylene diisocyanate, trimethylhexane diisocyanate or tetramethylhexane diisocyanate, cycloaliphatic diisocyanates such as 1, 4, 1, 3 or 1, 2-diisocyanatocyclohexane, the trans / trans, the cis / cis and the cis / trans isomers of 4,4'- or 2,4'-di (isocyanatocyclohexyl) methane, 1-isocyanato-3,3,5-trimethyl-5- (isocyanatomethyl) cyclohexane (isophorone diisocyanate), 2,2-bis (4-isocyanatocyclohexyl) -propane, 1, 3 or 1, 4-bis (isocyanatomethyl ) cyclohexane or 2,4- or 2,6-diisocyanato-1-methylcyclohexane and also aromatic diisocyanates such as 2,4- or 2,6-toluene diisocyanate and their isomer mixtures, m- or p-xylylene diisocyanate, 2,4'-diisocyanate. or 4,4'-diisocyanatodiphenylmethane and their Isomerengem 1, 3, o 1,4-phenylenediisocyanate, 1-chloro-2,4-phenylenediisocyanate, 1,5-naphthylenediisocyanate, diphenyl-4,4'-diisocyanate, 4,4'-diisocyanato-3,3'-dimethyldiphenyl,

3-Methyldiphenylmethane-4,4'-diisocyanate, 1, 4-diisocyanatobenzene or diphenyl ether-4,4'-diisocyanate.

There may also be mixtures of said diisocyanates.

Suitable polyisocyanates are polyisocyanates containing isocyanurate groups, uretdione diisocyanates, polyisocyanates containing biuret groups, polyisocyanates containing urethane or allophanate groups, polyisocyanates containing oxadiazinetrione groups, uretonimine-modified polyisocyanates of unbranched or branched C 4 -C 20 -alkylene diisocyanates, cycloaliphatic diisocyanates having a total of from 6 to 20 C atoms or aromatic diisocyanates having a total of 8 to 20 carbon atoms or mixtures thereof. The usable di- and polyisocyanates preferably have a content of isocyanate groups (calculated as NCO, equivalent weight = 42 g / mol) of 10 to 60 wt .-% based on the diisocyanate and polyisocyanate (mixture), preferably 15 to 60 wt .-% and particularly preferably 20 to 55 wt .-%. Preferred are aliphatic or cycloaliphatic di- and polyisocyanates, e.g. the abovementioned aliphatic or cycloaliphatic diisocyanates, or mixtures thereof.

Further preferred

1) isocyanurate-containing polyisocyanates of aromatic, aliphatic and / or cycloaliphatic diisocyanates. Particular preference is given here to the corresponding aliphatic and / or cycloaliphatic isocyanato isocyanurates and in particular those based on hexamethylene diisocyanate and isophorone diisocyanate. The isocyanurates present are, in particular, tris-isocyanatoalkyl- or tris-isocyanato-cycloalkyl isocyanurates, which are cyclic trimers of the diisocyanates, or mixtures with their higher homologs containing more than one isocyanurate ring. The isocyanato-isocyanurates generally have an NCO content of 10 to 30 wt .-%, in particular 15 to 25 wt .-% and an average

NCO functionality from 3 to 4.5. 2) uretdione diisocyanates having aromatic, aliphatic and / or cycloaliphatic bound isocyanate groups, preferably aliphatically and / or cycloaliphatically bonded and in particular those derived from hexamethylene diisocyanate or isophorone diisocyanate. Uretdione diisocyanates are cyclic dimerization products of diisocyanates.

The uretdione diisocyanates can be used in the preparations as the sole component or in a mixture with other polyisocyanates, in particular those mentioned under 1).

3) biuret polyisocyanates having aromatic, cycloaliphatic or aliphatic bound, preferably cycloaliphatic or aliphatic bound isocyanate groups, in particular tris (6-isocyanatohexyl) biuret or mixtures thereof with its higher homologues. These biuret polyisocyanates generally have an NCO content of 18 to 22 wt .-% and an average NCO functionality of 3 to 4.5.

4) polyisocyanates containing urethane and / or allophanate groups with aromatically, aliphatically or cycloaliphatically bonded, preferably aliphatically or cycloaliphatically bonded isocyanate groups, as obtained, for example, by reacting excess amounts of hexamethylene diisocyanate or of isophorone diisocyanate with polyhydric alcohols, such as e.g. Trimethylolpropane, neopentyl glycol, pentaerythritol, 1, 4-butanediol, 1, 6-hexanediol, 1, 3-propanediol, ethylene glycol, diethylene glycol, glycerol, 1, 2-dihydroxypropane or mixtures thereof can be obtained. These urethane and / or allophanate-containing polyisocyanates generally have an NCO content of 12 to 20 wt .-% and an average NCO functionality of 2.5 to 3.

5) oxadiazinetrione-containing polyisocyanates, preferably derived from hexamethylene diisocyanate or isophorone diisocyanate. Such oxadiazinetrione-containing polyisocyanates can be prepared from diisocyanate and carbon dioxide.

6) Uretonimine-modified polyisocyanates.

Particularly suitable mixtures of these isocyanates are the mixtures of the respective structural isomers of diisocyanatotoluene and diisocyanato-diphenylmethane, in particular the mixture of 20 mol% 2,4 diisocyanatotoluene and 80 mol% 2,6-diisocyanatotoluene suitable. Furthermore, the mixtures of aromatic isocyanates such as 2,4-diisocyanatotoluene and / or 2,6-diisocyanatotoluene with aliphatic or cycloaliphatic isocyanates such as hexamethylene diisocyanate or IPDI are particularly advantageous, the preferred mixing ratio of the aliphatic to aromatic isocyanates 4: 1 to 1 : 4.

As compounds (a) it is also possible to use isocyanates which, in addition to the free isocyanate groups, contain further blocked isocyanate groups, e.g. Wear uretdione or urethane troops.

Optionally, it is also possible to use those isocyanates which carry only one isocyanate group. In general, their proportion is at most 10 mol%, based on the total molar amount of the monomers. The monoisocyanates usually carry other functional groups such as olefinic groups or carbonyl groups and nen for the introduction of functional groups in the polyurethane, which allow the dispersion or the crosslinking or further polymer-analogous reaction of the polyurethane. Suitable for this purpose are monomers such as isopropenyl-α, α-dimethylbenzyl isocyanate (TMI).

Preferred diols (b) are relatively high molecular weight diols (b1) which have a molecular weight of about 500 to 5,000, preferably about 100 to 3,000, g / mol. The diols (b1) are, in particular, polyesterpolyols which are known, for example, from U Ilmann's Encyklopadie der technischen Chemie, 4th Edition, Volume 19, pages 62 to 65. Polyester polyols which are obtained by reacting dihydric alcohols A with dibasic carboxylic acids D are preferably used. Instead of the free polycarboxylic acids, it is also possible to use the corresponding polycarboxylic anhydrides or corresponding polycarboxylic acid esters of lower alcohols or mixtures thereof to prepare the polyesterpolyols. The polycarboxylic acids may be aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic and may optionally be substituted, for example by halogen atoms, and / or unsaturated. Examples of these are: suberic acid, azelaic acid, phthalic acid, isophthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylenetetrahydrophthalic anhydride, glutaric anhydride, maleic acid, maleic anhydride, fumaric acid, dimer fatty acids. Preference is given to dicarboxylic acids of the general formula HOOC- (CH 2) _y -COOH, where y is a number from 1 to 20, preferably an even number from 2 to 20, for example succinic acid, adipic acid, dodecanedicarboxylic acid and sebacic acid. Examples of suitable polyhydric alcohols A are ethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,3-diol, butene-1,4-diol, butyne-1,4-diol, pentane. 1, 5-diol, neopentyl glycol, bis (hydroxymethyl) cyclohexanes such as 1, 4-bis (hydroxymethyl) cyclohexane, 2-methyl-propane-1, 3-diol, furthermore diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, Dipropylene glycol, polypropylene glycol, dibutylene glycol and polybutylene glycols into consideration. Preference is given to neopentyl glycol and alcohols of the general formula HO- (CH 2) x -OH, where x is a number from 1 to 20, preferably an even number from 2 to 20. Examples of these are ethylene glycol, butane-1, 4-diol, hexane-1, 6-diol, octane-1, 8-diol and dodecane-1, 12-diol.

Also suitable are polycarbonate diols, as can be obtained, for example, by reacting phosgene with an excess of the low molecular weight alcohols mentioned as synthesis components for the polyesterpolyols. Also suitable are lactone-based polyesterdiols, which are homopolymers or copolymers of lactones, preferably terminal hydroxyl-containing addition products of lactones onto suitable difunctional starter molecules. Suitable lactones are preferably those derived from hydroxycarboxylic acids of the general formula HO- (CH 2) _z -COOH, where z is a number from 1 to 20, preferably an odd number from 3 to 19, for example ε-caprolactone, β-propiolactone, γ-butyrolactone and / or methyl-s-caprolactone and mixtures thereof. Suitable starter components are, for example, the low molecular weight dihydric alcohols mentioned above as the synthesis component for the polyesterpolyols. The corresponding polymers of ε-caprolactone are particularly preferred. Lower polyester diols or polyether diols can also be used as starters for the preparation of the lactone polymers. Instead of the polymers of lactones, it is also possible to use the corresponding, chemically equivalent polycondensates of the hydroxycarboxylic acids corresponding to the lactones.

In addition, suitable monomers (b1) are polyether diols. They are in particular by polymerization of ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin with itself, e.g. in the presence of BF3 or by addition of these compounds, optionally in admixture or one after the other, to starting components having reactive hydrogen atoms, such as alcohols or amines, e.g. Water, ethylene glycol, propane-1, 2-diol, propane-1, 3-diol, 2,2-bis (4-hydroxydiphenyl) propane or aniline available. Particularly preferred is polytetrahydrofuran having a molecular weight of 500 to 5000 g / mol, and especially 1000 to

4500 g / mol. The polyester diols and polyether diols can also be used as mixtures in a ratio of 0.1: 1 to 1: 9.

As diols (b) it is possible, in addition to the diols (b1), to use low molecular weight diols (b2) having a molecular weight of about 50 to 500, preferably from 60 to 200, g / mol.

The monomers (b2) used are, in particular, the synthesis components of the short-chain alkanediols mentioned for the preparation of polyester polyols, where the unbranched diols having 2 to 12 carbon atoms and an even number of carbon atoms and pentanediol-1, 5 and neopentyl glycol to be favoured.

The proportion of diols (b1), based on the total amount of diols (b), is preferably 10 to 100 mol% and the proportion of diols (b2), based on the total amount of diols (b), is 0 to 90 mol -%. The ratio of the diols (b1) to the diols (b2) is particularly preferably from 0.2: 1 to 5: 1, particularly preferably from 0.5: 1 to 2: 1.

According to the invention, suitable diols b), preferably b1), are at least partially polyester polyols PES based on at least one polyhydric alcohol A and at least one dicarboxylic acid D, wherein at least one polyhydric alcohol A and / or at least one dicarboxylic acid D at least partially renewable raw materials was obtained, as described above. In one embodiment, diols used are b), preferably b1), at least 10% by weight, preferably at least 30% by weight, more preferably at least 50% by weight, very preferably at least 70% by weight and especially preferably at least 90% by weight Polyester polyols PES, which are based on at least one polyhydric alcohol A and at least one dicarboxylic acid D, wherein at least one polyhydric alcohol A and / or at least one dicarboxylic acid D was obtained at least partially from renewable raw materials.

In one embodiment, as diols b), preferably b1) exclusively polyester polyols PES are used, based on at least one polyhydric alcohol A and at least one dicarboxylic acid D, wherein at least one polyhydric alcohol A and / or at least one dicarboxylic acid D at least partially from renewable raw materials was won.

The monomers (c) other than the diols (b) generally serve for crosslinking or chain extension. They are generally more than divalent non-aromatic alcohols, amines having 2 or more primary and / or secondary amino groups, and compounds which, in addition to one or more alcoholic Hydroxyl groups carry one or more primary and / or secondary amino groups.

Alcohols of a higher valence than 2, which may serve to establish a certain degree of branching or crosslinking, are known, for example. Trimethylolbutane, trimethylolpropane, trimethylolethane, pentaerythritol, glycerol, sugar alcohols, such as e.g. Sorbitol, mannitol, diglycerol, threitol, erythritol, adonite (ribitol), arabitol (lyxite), xylitol, dulcitol (galactitol), maltitol or isomalt, or sugar. Also suitable are monoalcohols which, in addition to the hydroxyl group, carry a further isocyanate-reactive group, such as monoalcohols having one or more primary and / or secondary amino groups, e.g. Monoethanolamine.

Polyamines having 2 or more primary and / or secondary amino groups can be used in the prepolymer mixing process, especially if the chain extension or crosslinking in the presence of water to take place (step III), as a mine usually faster than alcohols or Water react with isocyanates. This is often required when aqueous dispersions of high molecular weight crosslinked polyurethanes or polyurethanes are desired. In such cases, prepolymers having isocyanate groups are prepared, these are rapidly dispersed in water and then chain-extended or crosslinked by addition of compounds having a plurality of isocyanate-reactive amino groups.

Amines suitable for this purpose are generally polyfunctional amines of the molecular weight range from 32 to 500 g / mol, preferably from 60 to 300 g / mol, which contain at least two primary, two secondary or at least one primary and one secondary amino group. Examples of these are diamines such as diaminoethane, diaminopropane, diaminobutanes, diaminohexanes, piperazine, 2,5-dimethylpiperazine, amino-3-aminomethyl-3,5,5-trimethyl-cyclohexane (isophoronediamine, IPDA), 4,4 ' Diaminodicyclohexylmethane, 1,4-diaminocyclohexane, aminoethylethanolamine, hydrazine, hydrazine hydrate or triamines such as diethylenetriamine or 1,8-diamino-4-aminomethyloctane or higher amines such as triethylenetetramine, tetraethylenepentamine or polymeric amines such as polyethyleneamines, hydrogenated polyacrylonitriles or at least partially hydrolyzed poly-N-vinylformamide each having a molecular weight of up to 2000, preferably up to 1000 g / mol.

The amines can also be used in blocked form, for example in the form of the corresponding ketimines (see, for example, CA-1 129 128), ketazines (cf., for example, US Pat. No. 4,269,748) or amine salts (see US Pat. No. 4,292,226) become. Oxazolidines, as used for example in US Pat. No. 4,192,937, are also blocked polyamines used for the preparation of the polyurethanes for chain extension of the prepolymers can be. When using such capped polyamines they are generally mixed with the prepolymers in the absence of water and this mixture is then mixed with the dispersion water or a part of the dispersion water, so that the corresponding polyamines are hydrolytically released.

Preference is given to using mixtures of di- and triamines, more preferably mixtures of isophoronediamine and diethylenetriamine. The proportion of polyamines can be up to 10, preferably up to 8 mol% and particularly preferably up to 5 mol%, based on the total amount of components (b) and (c).

The polyurethane prepared in step I can as a rule have up to 10% by weight, preferably up to 5% by weight, of unreacted NCO groups.

The molar ratio of NCO groups in the polyurethane produced in step I to the sum of primary and secondary amino groups in the polyamine is generally selected in step III to be between 3: 1 and 1: 3, preferably 2: 1 and 1 : 2, more preferably 1, 5: 1 and 1: 1.5; most preferably at 1: 1.

Furthermore, chain termination in minor amounts, i. preferably in amounts of less than 10 mol%, based on the components (b) and (c), monoalcohols are used. They serve mainly to limit the molecular weight of the polyurethane. Examples are methanol, ethanol, isopropanol, n-propanol, n-butanol, isobutanol, sec-butanol, tert-butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 1,3-propanediol monomethyl ether, n-hexanol, n- Heptanol, n-octanol, n-decanol, n-dodecanol (lauryl alcohol) and 2-ethylhexanol.

In order to achieve the water-dispersibility of the polyurethanes, the polyurethanes, besides components (a), (b) and (c), are monomers (d) which are different from components (a), (b) and (c) and have at least one isocyanate group or at least one group which is reactive toward isocyanate groups and moreover at least one hydrophilic group or a group which can be converted into hydrophilic groups. In the following text, the term "hydrophilic groups or potentially hydrophilic groups" is abbreviated to "(potentially) hydrophilic groups". The (potentially) hydrophilic groups react much more slowly with isocyanates than the functional groups of the monomers which serve to build up the polymer main chain. The (potentially) hydrophilic groups may be nonionic or, preferably, ionic, ie cationic or anionic, hydrophilic groups or potentially ionic hydrophilic groups, and more preferably anionic hydrophilic groups Groups or act on potentially anionic hydrophilic groups.

The proportion of components with (potentially) hydrophilic groups in the total amount of components (a), (b), (c) and (d) is generally such that the molar amount of (potentially) hydrophilic groups, based on the amount by weight of all monomers (a) to (b), 30 to 1000, preferably 50 to 500 and particularly preferably 80 to 300 mmol / kg.

Suitable nonionic hydrophilic groups are, for example, mixed or pure polyethylene glycol ethers of preferably 5 to 100, preferably 10 to 80, repeating units of ethylene oxide. The polyethylene glycol ethers may also contain propylene oxide units. If this is the case, the content of propylene oxide units should not exceed 50% by weight, preferably 30% by weight, based on the mixed polyethylene glycol ether.

The content of polyethylene oxide units is generally 0 to 10, preferably 0 to 6 wt .-%, based on the amount by weight of all monomers (a) to (d).

Preferred monomers with nonionic hydrophilic groups are the polyethylene glycol and diisocyanates which carry a terminally etherified polyethylene glycol radical. Such diisocyanates and processes for their preparation are disclosed in US Pat. Nos. 3,905,929 and 3,920,598.

Ionic hydrophilic groups are especially anionic groups such as the sulfonate, the carboxylate and the phosphate group in the form of their alkali metal or ammonium salts and cationic groups such as ammonium groups, in particular protonated tertiary amino groups or quaternary ammonium groups.

Suitable monomers with potentially anionic groups are usually aliphatic, cycloaliphatic, araliphatic or aromatic mono- and dihydroxycarboxylic acids which carry at least one alcoholic hydroxyl group or one primary or secondary amino group.

Such compounds are exemplified by the general formula

RG-R ⁴ -DG, wherein RG is at least one isocyanate-reactive group

DG at least one (potentially) hydrophilic group and R ^{4 is} an aliphatic, cycloaliphatic or aromatic radical containing 1 to 20 carbon atoms.

Examples of RG are -OH, -SH, -NH ₂ or -NHR ^5, wherein R ⁵ is methyl, ethyl, / ^'so-propyl, n-propyl, n-butyl, / so-butyl, s / butyl, feri Butyl, cyclopentyl or cyclohexyl can be.

Preferably such components are e.g. mercaptoacetic acid, mercaptopropionic acid, thiolactic acid, mercaptosuccinic acid, glycine, iminodiacetic acid, sarcosine, alanine, β-alanine, leucine, isoleucine, aminobutyric acid, hydroxyacetic acid, hydroxypivalic acid, lactic acid, hydroxysuccinic acid, hydroxydecanoic acid, dimethylolpropionic acid, dimethylolbutyric acid, ethylenediaminetriacetic acid, hydroxy dodecanoic acid, hydroxyhexadecanoic acid, 12-hydroxystearic acid, aminonaphthalenecarboxylic acid, hydroxethanesulfonic acid, hydroxypropanesulfonic acid, mercaptoethanesulfonic acid, mercaptopropanesulfonic acid, aminomethanesulfonic acid, taurine, aminopropanesulfonic acid, N-cyclohexylaminopropanesulfonic acid, N-cyclohexylaminoethanesulfonic acid and their alkali, alkaline earth or ammonium salts and particularly preferably the monohydroxycarboxylic and -sulfonsäuren and Monoaminocar- bon- and -sulfonsäuren.

Very particular preference is given to dihydroxyalkylcarboxylic acids, in particular having 3 to 10 carbon atoms, as are also described in US Pat. No. 3,412,054. In particular, compounds of the general formula HO-R ¹ -CR ³ (COOH) -R ² -OH in which R ¹ and R ^{2 are} a C 1 to C ₄ alkanediyl moiety and R ^{3 is} a C 1 to C ₄ al - kyl unit stands. Above all, dimethylol butyric acid and especially dimethylolpropionic acid (DMPA) are preferable.

Also suitable are corresponding dihydroxysulfonic acids and dihydroxyphosphonic acids, such as 2,3-dihydroxypropanephosphonic acid, and the corresponding acids in which at least one hydroxyl group has been replaced by an amino group, for example those of the formula

H ₂ NR -CR ³ (COOH) -R ² -NH ₂ in which R ¹ , R ² and R ^{3 may have} the same meanings as stated above. Otherwise suitable are dihydroxy compounds having a molecular weight above 500 to 10,000 g / mol with at least 2 carboxylate groups, which are known from DE-A 4,140,486. They are obtainable by reacting dihydroxyl compounds with tetracarboxylic acid dianhydrides such as pyromellitic dianhydride or cyclopentanetetracarboxylic anhydride in a molar ratio of 2: 1 to 1:05 in a polyaddition reaction. Particularly suitable dihydroxy compounds are the monomers (b2) listed as chain extenders and the diols (b1).

Potentially ionic hydrophilic groups are, above all, those which can be converted by simple neutralization, hydrolysis or quaternization reactions into the above-mentioned ionic hydrophilic groups, e.g. Acid groups, anhydride groups or tertiary amino groups.

Ionic monomers (d) or potentially ionic monomers (d) are e.g. in Ullmann's Encyklopadie der technischen Chemie, 4th Edition, Volume 19, pp. 311-313 and for example in DE-A 1 495 745.

Particularly preferred monomers for cationic monomers (d) are monomers having tertiary amino groups, for example: tris (hydroxyalkyl) amines, N, N'-bis (hydroxyalkyl) alkylamines, N-hydroxyalkyl-dialkylamines, tris ( aminoalkyl) -amines, N, N'-bis (aminoalkyl) -alkylamines, N-aminoalkyl-dialkylamines, where the alkyl radicals and alkanediyl units of these tertiary amines independently of one another consist of 2 to 6 carbon atoms. Further, polyethers having tertiary nitrogen atoms preferably having two terminal hydroxyl groups, e.g. by the alkoxylation of two amine-containing hydrogen atoms, e.g. Methylamine, aniline, or Ν, Ν'-dimethylhydrazine, in a conventional manner are accessible, into consideration. Such polyethers generally have a molecular weight between 500 and 6000 g / mol. These tertiary amines are either with acids, preferably strong mineral acids such as phosphoric acid, sulfuric acid or hydrohalic acids, strong organic acids such as formic, acetic or lactic acid, or by reaction with suitable quaternizing agents such as C 1 to C 6 alkyl halides, e.g. Bromides or chlorides, or di-Cd-C6-alkyl sulfates or di-d- to C6-Alkylcarbon- bonaten converted into the ammonium salts.

Suitable monomers (d) with isocyanate-reactive amino groups are amino carboxylic acids such as lysine, β-alanine, the adducts of aliphatic diprimary diamines mentioned in DE-A2034479 to α, β-unsaturated carboxylic acids such as N- (2-aminoethyl ) -2-aminoethanecarboxylic acid and the corresponding N-aminoalkylamino noalkylcarboxylic acids, wherein the alkanediyl units consist of 2 to 6 carbon atoms, into consideration.

If monomers having potentially ionic groups are used, their conversion into the ionic form may take place before, during, but preferably after the isocyanate polyaddition, since the ionic monomers are often difficult to dissolve in the reaction mixture. The anionic hydrophilic groups are particularly preferably in the form of their salts with an alkali ion or an ammonium ion as the counterion.

Hydroxycarboxylic acids are preferred among these compounds, with particular preference being given to dihydroxyalkylcarboxylic acids, very particular preference to a, a-bis (hydroxymethyl) -carboxylic acids, in particular dimethylolbutyric acid and dimethylolpropionic acid, and especially dimethylolpropionic acid.

In an alternative embodiment, the polyurethanes may contain both nonionic hydrophilic and ionic hydrophilic groups, preferably simultaneously nonionic hydrophilic and anionic hydrophilic groups. In the field of polyurethane chemistry, it is well known how the molecular weight of the polyurethanes can be adjusted by selecting the proportions of the monomers reactive with one another and the arithmetic mean of the number of reactive functional groups per molecule. Normally, the components (a), (b), (c) and (d) and their respective molar amounts are chosen so that the ratio A: B with

A) the molar amount of isocyanate groups and

B) the sum of the molar amount of the hydroxyl groups and the molar amount of the functional groups which can react with isocyanates in an addition reaction

0.5: 1 to 2: 1, preferably 0.8: 1 to 1, 5, particularly preferably 0.9: 1 to 1, 2: 1. Most preferably, the ratio A: B is as close as possible to 1: 1. In addition to components (a), (b), (c) and (d), monomers having only one reactive group are generally added in amounts of up to 15 mol%, preferably up to 8 mol%, based on the total amount of the components (a), (b), (c) and (d) used. The polyaddition of components (a) to (d) is generally carried out at reaction temperatures of 20 to 180 ° C, preferably 50 to 150 ° C under atmospheric pressure.

The required reaction times can range from a few minutes to a few hours. It is known in the field of polyurethane chemistry how the reaction time is influenced by a large number of parameters such as temperature, concentration of the monomers, reactivity of the monomers.

To accelerate the reaction of the diisocyanates, the conventional catalysts can be used. In principle, all catalysts customarily used in polyurethane chemistry come into consideration.

These are, for example, organic amines, in particular tertiary aliphatic, cycloaliphatic or aromatic amines, and / or Lewis-acidic organic metal compounds. As the Lewis acidic organic metal compounds, e.g. Tin compounds, such as tin (II) salts of organic carboxylic acids, e.g. Tin (II) acetate, tin (II) octoate, tin (II) ethyl hexoate and tin (II) laurate and the dialkyltin (IV) salts of organic carboxylic acids, eg dimethyltin diacetate, di-butyltin diacetate, dibutyltin dibutyrate, dibutyltin bis (2-ethylhexanoate), dibutyltin dilaurate, dibutyltin maleate, dioctyltin dilaurate and dioctyltin diacetate. Metal complexes such as acetylacetonates of iron, titanium, aluminum, zirconium, manganese, nickel and cobalt are also possible. Other metal catalysts are described by Blank et al. in Progress in Organic Coatings, 1999, Vol. 35, pages 19-29.

Preferred Lewis-acidic organic metal compounds are dimethyltin diacetate, dibutyltin dibutyrate, dibutyltin bis (2-ethylhexanoate), dibutyltin dilaurate, diocytotin dilaurate, zirconium acetylacetonate and zirconium 2,2,6,6-tetramethyl-3, 5-heptanedionate.

Also bismuth and cobalt catalysts and cesium salts can be used as catalysts. Suitable cesium salts are those compounds in which the following anions are used: F ^~ C, CIO-, CIO3 ^" , CIO4 ^" , Br, J-, JO3 ^" , CN-, OCN-, NO2-, NO3-, HCO3 -, CO3 ² -, S ² -, SH-, HSO ³ -, SO 3 ² -, HSO ₄ -, SO ₄ ² -, S2O ^{2 2} -, S2O4 ² -, S ₂ 0 ₅ ² -, S ₂ 0 ₆ ² -, S2O7 ² -, S ₂ 0 ₈ ² -, H2PO2-, H2PO4-, HPO4 ² -, PO4 ³ -, P2O7 ⁴ -,

(OCnH2n + i) ^" , (CnH2n-iO2) ^" , and (C _n + i where n is the numbers 1 to 20. Cesium carboxylates are preferred in which the anion obeys the formulas (CnH 2n-iO 2) ^" and (Cn + i H 2n-204) ^2" where n is 1 to 20. Particularly preferred cesium salts have, as anions, monocarboxylates of the general formula (CnH 2n-iO 2) ^" , where n is the numbers 1 to 20. Formate, acetate, propionate, hexanoate and 2-ethylhexanoate are to be mentioned here in particular.

Rührkessel come into consideration as polymerization, especially when provided by the concomitant use of solvents for a low viscosity and good heat dissipation.

If the reaction is carried out in bulk, extruders, in particular self-cleaning multiple-screw extruders, are particularly suitable because of the usually high viscosities and the usually short reaction times.

In the so-called "prepolymer mixing process", first a prepolymer is prepared which carries isocyanate groups. The components (a) to (d) are in this case chosen so that the ratio A: B is greater than 1, 0 to 3, preferably 1, 05 to 1, 5. The prepolymer is first dispersed in water and simultaneously and / or chain-extended by reaction of the isocyanate groups with amines carrying more than 2 isocyanate-reactive amino groups, or with amines containing 2 isocyanate-reactive amino groups, chain extended. Chain extension also occurs when no amine is added. In this case, isocyanate groups are hydrolyzed to amino groups, which react with remaining isocyanate groups of the prepolymers with chain extension.

The mean particle size (z average), measured by dynamic light scattering with the Malvern® Autosizer 2 C, the dispersions according to the invention is not essential to the invention and is generally <1000 nm, preferably <500 nm, more preferably <200 nm and most preferably between 20 and below 200 nm. Polyurethane dispersions PUD generally have a solids content of 10 to 75, preferably from 20 to 65 wt .-% and a viscosity of 10 to 500 mPas (measured at a temperature of 20 ° C and a shear rate of 250 s ^_1 .

For some applications it may be useful to adjust the polyurethane dispersions PUD to another, preferably a lower, solids content, for example by dilution.

In addition, polyurethane dispersions PUD can be mixed with other components typical of the applications mentioned, for example surfactants, detergents, dyes, pigments, dye transfer inhibitors and optical brighteners. The dispersions may be subjected to physical deodorization after preparation, if desired.

A physical deodorization may consist in that the dispersion with water vapor, an oxygen-containing gas, preferably air, nitrogen or supercritical carbon dioxide, for example, in a stirred tank, as described in DE-AS 12 48 943, or in a countercurrent column, as in DE-A 196 21 027 described, is stripped. The amount of the solvent S according to the invention in the preparation of the polyurethane is generally selected so that the proportion in the finished aqueous polyurethane dispersion, that is, after step II and optionally step III, does not exceed 30% by weight, preferably not more than 25 , more preferably not more than 20 and most preferably not more than 15 wt .-%.

The proportion of solvent S in the finished aqueous polymer dispersion, in particular polyurethane dispersion, is generally at least 0.01% by weight, preferably at least 0.1, particularly preferably at least 0.2, very particularly preferably at least 0.5 and in particular at least 1% by weight. ,

Polyurethane dispersions PUD, in particular aqueous polyurethane dispersions PUD, are advantageously suitable for coating, impregnating and bonding substrates. Suitable substrates are wood, wood veneer, paper, cardboard, textiles, leather, artificial leather, fleece, plastic surfaces, glass, ceramics, mineral building materials, clothing, vehicle interiors, vehicles, metals or coated metals. They are used, for example, in the production of films or films, for impregnating textiles or leather, as dispersants, as pigment driers, as primers, as adhesion promoters, as water repellents, as detergent additive or as additive in cosmetic preparations or for the production of moldings or hydrogels.

When used as coating compositions, polyurethane dispersions PUD can be used in particular as primers, fillers, pigmented topcoats and clearcoats in the field of car repair or large vehicle painting. The coating compositions are particularly suitable for applications in which a particularly high application safety, outdoor weathering resistance, appearance, solvent resistance, chemical resistance and water resistance are required, such as in car repair and large vehicle painting. The polyurethane dispersions PUD invention are very environmentally friendly by the use of renewable raw material and show properties that are at least equivalent to those based on petrochemical raw materials. In addition, polyurethane dispersions of PUD or polyurethane dispersions prepared by the process according to the invention show at least one of the following advantages over polymer dispersions or polyurethane dispersions known from the prior art: ^" an improved LCA through the use of renewable raw materials.

Another object of the present invention are polyurethane dispersions prepared by a process according to the invention. Another object of the present invention are coating compositions comprising at least one polyurethane dispersion according to the invention and articles coated therewith.

Another object of the invention is the use of polyurethane dispersions of the invention for coating, bonding or impregnation of surfaces such as leather, wood, textile, synthetic leather, metal, plastics, clothing, furniture, automotive interiors, vehicles, paper, organic polymers, in particular polyurethane.

Another object of the invention are coating compositions containing aqueous polyurethane dispersions and coating compositions which have been prepared from polyurethane dispersions of the invention.

Examples:

Polyesterol 1 is composed of sebacic acid (from renewable raw materials), adipic acid (molar ratio 1/1) and propanediol-1, 3 (from renewable raw materials), molecular weight 1400 g / mol.

Polyesterol 2 is composed of adipic acid, neopentyl glycol and hexanediol-1, 6 (molar ratio 1/1), molecular weight 1400 g / mol.

example 1 420 g (0.30 mol) of polyesterol 1, 27.0 g of 1,4-butanediol, 100 g of acetone and 0.30 ml of dibutyltin dilaurate were placed in a stirred vessel with thermometer and reflux condenser and heated to 65.degree. To this was added 89.8 g (0.404 mol) of isophorone diisocyanate and 106.7 g of 4,4'-dicyclohexylmethane diisocyanate and stirred at 95 ° C. After 210 minutes, it was diluted with 850 g of acetone.

The NCO content of the solution was determined to be 1.16% (calculated: 1.10%).

The solution was cooled to 50 ° C and 42.0 g (0.10 mol) of a 40% aqueous solution of the Michael adduct of ethylene diamine added to sodium acrylate. Then was dispersed by adding 1200 g of water. Immediately after the end of the dispersion, a mixture of 50 g of water, 2.7 g (0.016 mol) of isophoronediamine and 5.8 g (0.056 mol) of diethylenetriamine was added.

After distillation of the acetone, a finely divided polyurethane dispersion having a solids content of 37.2% was obtained. Example 2 (comparison)

420 g (0.30 mol) of polyesterol 2, 27.0 g of 1,4-butanediol, 100 g of acetone and 0.30 ml of dibutyltin dilaurate were placed in a stirred vessel with thermometer and reflux condenser and heated to 65.degree. To this was added 89.8 g (0.404 mol) of isophorone diisocyanate and 106.7 g of 4,4'-dicyclohexylmethane diisocyanate and stirred at 95 ° C. After 210 minutes, it was diluted with 850 g of acetone.

The NCO content of the solution was determined to be 1.16% (calculated: 1.10%).

After distillation of the acetone, a finely divided polyurethane dispersion having a solids content of 38.4% was obtained.

Out

120 g Lepton Black NB

150 g Lepton Filing FCG,

400 g of polyurethane dispersion and

100 g of Corial Ultrasoft NT liquors were prepared and thickened with Lepton Paste VL to an outlet viscosity of 35 sec in Ford cup 4 mm. These liquors were applied to full grain leather using a 8.0 g / ft ² reverse roll coater. Lepton ^® Black NB is a carbon (soot) -based pigment preparation from BASF SE for use in aqueous finishes.

Lepton ^® Filier FCG is an aqueous dispersion of inorganic matting agents with casein, grease and waxes from BASF SE for use in aqueous finishes.

Corial ^® Ultrasoft NT is an aqueous acrylate polymer dispersion from BASF SE for use in aqueous finishes. Lepton ^® Paste VL is a PU dispersion in the mixture with water and higher-grade alcohols from BASF SE for use in aqueous finishes.

Table 1 summarizes the test results:

Polyurethane dispersions according to the invention, which are based on renewable raw materials, have the same service properties, such as polyurethane dispersions, which are composed of petrochemical raw materials.

Claims

claims

1 . Polyurethane dispersion PUD comprising at least one polyurethane P based on at least one polyisocyanate and at least one polyester polyol PES, wherein the polyester polyol PES based on at least one polyhydric alcohol A and at least one dicarboxylic acid D, wherein at least one polyhydric alcohol A and / or at least one dicarboxylic acid D at least partially was derived from renewable raw materials.

2. The polyurethane dispersion according to claim 1, wherein the at least one dicarboxylic acid D is sebacic acid, azelaic acid, succinic acid, furandicarboxylic acid or tetrahydrofurandicarboxylic acid.

3. Polyurethane dispersion according to one of claims 1 to 2, wherein the at least one dicarboxylic acid comprises D sebacic acid, which was obtained at least partially from renewable raw materials, and adipic acid.

4. Polyurethane dispersion according to any one of claims 1 to 3, wherein the at least one polyhydric alcohol A has been obtained at least partially from renewable raw materials.

5. A polyurethane dispersion according to any one of claims 1 to 4, wherein the at least one polyhydric alcohol A is selected from the group consisting of C2-C6 aliphatic diols.

6. A polyurethane dispersion according to any one of claims 1 to 5, wherein the at least one polyvalent is selected from the group consisting of 1, 3-propanediol and 1, 4-butanediol.

7. Polyurethane dispersion according to one of claims 1 to 6, wherein the polyurethane contains at least one chain extender.

8. A polyurethane dispersion according to any one of claims 1 to 7, wherein the polyurethane dispersion is aqueous.

9. A process for preparing a polyurethane dispersion comprising the reaction of at least one polyisocyanate and at least one polyester polyol PES, wherein the polyester polyol PES based on at least one polyhydric alcohol A and at least one dicarboxylic acid D, wherein at least one polyhydric alcohol A and / or at least one dicarboxylic acid D at least partially derived from renewable raw materials. Method according to claim 9, comprising the following steps:

I. Preparation of a polyurethane by reacting a) at least one polyfunctional isocyanate having 4 to 30 carbon atoms, b) diols, of which b1) 10 to 100 mol%, based on the total amount of diols (b), a molecular weight of Have from 500 to 5000, and b2) from 0 to 90 mol%, based on the total amount of the diols (b), have a molecular weight of 60 to 500 g / mol, c) optionally further of the diols (b) different polyvalent compounds with reactive groups which are alcoholic hydroxyl groups or primary or secondary amino groups; and d) monomers other than monomers (a), (b) and (c) having at least one isocyanate group or at least one isocyanate group reactive group in addition, at least one hydrophilic group or a potentially hydrophilic group, whereby the water dispersibility of the polyurethanes is effected, to a polyurethane in the presence of a solvent S and

II. Subsequent dispersion of the polyurethane in water,

III. optionally after or during step II can add polyamines, wherein diol b1) comprises at least one polyester polyol PES based on at least one polyhydric alcohol A and at least one dicarboxylic acid D, wherein at least one polyhydric alcohol A and / or at least one dicarboxylic acid D was at least partially obtained from regrowing the raw materials.

Polyurethane dispersion prepared by a process according to claim 9 or 10. Use of polyurethane dispersions according to claims 1 to 10 or prepared by a process according to claims 1 to 12 for the coating, impregnation or bonding of wood, wood veneer, paper, cardboard, cardboard, textile, leather, artificial leather, fleece, plastic surfaces, glass , Ceramics, mineral building materials, clothing, vehicle interiors, vehicles, metals or coated metals.

Coating composition comprising an aqueous polyurethane dispersion PUD according to Claims 1 to 10 or prepared by a process according to Claims 1 to 12.