WO2003068879A1

WO2003068879A1 - Aqueous coating agent based on epoxybutene polyethers

Info

Publication number: WO2003068879A1
Application number: PCT/EP2003/001613
Authority: WO
Inventors: Martin Melchiors; Jan Weikard; Rolf Gertzmann; Helmut Greiving; Ulrich Freudenberg; Peter J. Miller
Original assignee: Bayer Materialscience Ag; Bayer Materialscience Llc
Priority date: 2002-02-18
Filing date: 2003-02-18
Publication date: 2003-08-21
Also published as: HK1081216A1; CN1646647A; EP1485438A1; CN1293119C; AU2003210298A1; CA2476476A1; JP2005517761A

Abstract

The invention relates to water-dilutable polyurethanes comprising structural units derived from 3,4-epoxy-1-butene, and aqueous dispersions containing said polyurethanes. The invention also relates to a method for producing said polyurethanes and to the use of the same as aqueous, oxidatively drying and/or UV-crosslinking coating agents.

Description

Aqueous coating agents based on epoxybutene polyethers

The invention relates to water-dilutable polyurethanes which have structural units derived from 3,4-epoxy-1-butene, and to aqueous dispersions which contain these polyurethanes, a process for their preparation and use as aqueous oxidatively drying and / or UV-crosslinking coating compositions ,

Polymeric compounds which can contain the structural units of 3,4-epoxy-1-butene are known in principle. In EP-A 0 217 660, for example

Preparation of poly (α-hydroxycarboxylic acid) copolymers described using ethylenically unsaturated epoxides.

US Pat. No. 5,393,867 discloses hydroxy-functional polyethers which are obtained by polymerizing 3,4-epoxy-1-butene with palladium catalysts.

EP-A 0 859 021 describes compounds with pendant vinyl groups which, by reacting (a) compounds which contain at least one vinyl group and at least one epoxy group, (b) a polybasic compound or its anhydride and optionally (c) a CH-acidic compound are prepared and their epoxidized derivatives.

WO 00/66646 discloses oil-free, oxidatively drying polyester resins which are obtained by derivatizing carboxyl-functional polyesters with 3,4-epoxy-1-butene, and drying the use of these resins in combination with an organic solvent and a drying catalyst in room temperature - the coatings.

Finally, WO 00/66649 discloses coating compositions based on polyether alcohols, which by ring-opening polymer tion of 3,4-epoxybutene can be prepared with water or alcohols. The polyether alcohols produced in this way can serve as reactive thinners or binders in oxidatively drying coatings and as building blocks for such binders.

A disadvantage of the aqueous one-component lacquers previously known in lacquer technology is that, for example, the drying of oxidatively crosslinking water lacquers at room temperature often proceeds only slowly, even with the addition of siccatives as drying accelerators, and only moderate film hardness is achieved. UV-curing aqueous one-component paints, on the other hand, have an inadequate

Networking in areas that have been exposed to a lower dose of UV radiation or not at all (shadow areas). The paint films have an inferior property level at these points.

It was therefore an object of the present invention to provide aqueous dispersions which are capable of oxidative drying and / or crosslinking with UV light and which can be processed into single-component paints with a high level of properties, in particular with regard to film appearance, hardness, resistance to solvents and weather, and rapid drying.

This object was achieved by providing a water-thinnable polymer containing urethane groups, which has the structural units of 3,4-epoxy-1-butene and which can be used as the basis for a one-component aqueous dispersion.

The present invention thus relates to a water-dilutable, urethane-containing polymer with ionic and / or potentially ionic groups, characterized in that the polymer contains the repeating units (AI) of the formula (I) and / or (A2) of the formula (II), CH = CH "

-O- -CH— CH - -O- -CH— CH = CH— CH—

(I) (II) contains.

The repeat units AI, A2 or mixtures A1 / A2 are in the polymer

blocks

or in blocks composed of two structural units with p repetition units, where n, m, p each represent integers from 3 to 100.

It is also possible that the AI or A2 repeat units are distributed differently in the co-polymer.

The content of Al and / or A2 units in the polymer according to the invention is 2 to 80% by weight, preferably 5 to 50% by weight, particularly preferably 8 to 35% by weight.

The structural units AI and / or A2 contained in the polymers according to the invention can be obtained by opening the epoxy ring of 3,4-epoxy-1-butene. It is possible to add 3,4-epoxy-1-butene (single or multiple) to nucleophilic centers of a polymer or oligomer chain by opening the epoxy ring, e.g. an addition to COOH, OH or NH functional chain ends. On the other hand, it is also possible to use a polyether alcohol oligomer or polymer with one or more OH groups, prepared by ring-opening polymerization of 3,4-epoxy-1-butene, optionally in the presence of other monomers polymerizable under these conditions, such as e.g. Ethylene oxide, propylene oxide or

Use butylene oxide as building blocks to build the polyurethane chain. The structural units AI and / or A2 are preferably introduced into the polyurethanes by incorporating hydroxy-functional polyether polyols. Apart from initiator constituents built into the chain, the polyether polyols can be composed entirely of repeating units Al and / or A2 (homopolymer) or else as a copolymer with other monomers polymerizable under these conditions, for example with ethylene oxide, propylene oxide or butylene oxide. A macroinitiator containing repeating units from the above-mentioned comonomers can be used for the production of polyether alcohols by homopolymerizing 3,4-epoxy-1-butene. Suitable catalysts for the production of the polyether alcohols are, for example, KOH, trifluoromethanesulfonic acid or their salts with yttrium or other lanthanide metals, palladium (0) compounds corresponding to US Pat. No. 5,393,867, such as tetrakistrisphenylphosphine-palladium (O).

In the ring-opening polymerization of 3,4-epoxybutene with alcohols as starters to polyether alcohols, double metal cyanide catalysis (DMC-

Catalysis). DMC catalysts and the polymerization of epoxides with such catalysts are e.g. in EP-A 0 700 949.

The polymer according to the invention contains 1 to 40% by weight of urethane groups [NHCOO], preferably 2 to 30% by weight of urethane groups, particularly preferably 5 to 25% by weight and very particularly preferably 15 to 25% by weight of urethane groups.

Furthermore, the polymers according to the invention contain a total of 9 to 100 meq / lOOg of ionic and / or potentially ionic groups in order to achieve dispersibility or solubility in an aqueous medium. The content of the ionic and / or potentially ionic groups is preferably in total 20 to 60 meq / 100 g, particularly preferably in total 25 to 50 meq / 100 g.

The water-dilutable polymer according to the invention is preferably a reaction product A) containing the components (al) 5 to 80% by weight, preferably 10 to 60% by weight, of polyisocyanates,

(a2) 10 to 80% by weight, preferably 40 to 70% by weight, of polyols and / or polyamines with an average molecular weight M _n of at least 400,

(a3) 2 to 15% by weight, preferably 3 to 10% by weight, of compounds which have at least one group which is reactive toward isocyanate groups and at least one ionic and / or potentially ionic group,

(a4) 0 to 20% by weight, preferably 1 to 10% by weight of low molecular weight polyols and / or secondary polyamines,

(a5) 0 to 20% by weight chain stopper,. (a6) 0 to 20% by weight of chain extenders which have at least two groups which are reactive toward isocyanate groups and which are different from (a2), (a3) and (a4).

The water-dilutable polymers according to the invention have an average molecular weight M _n of 1,000 to 50,000, preferably 1,600 to 10,000.

The polyisocyanates, preferably diisocyanates (al), are the compounds known in the polyurethane or paint field, such as aliphatic, cycloaliphatic or aromatic diisocyanates.

Compounds of the general formula Q (NCO) ₂ are suitable, Q being a hydrocarbon radical having 4 to 40 C atoms, preferably 4 to 20 C atoms. Q is preferably an aliphatic C ₄ -C ₂ radical, a cycloaliphatic C ₆ -C ₅ radical, an aromatic C ₆ -C ₅ radical or an araliphatic C -C ₅ radical.

Particularly preferred diisocyanates are, for example, tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,4-diisocyanatocyclohexane, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate), 4,4'-diisocyanatodicyclohexyl methane, 4,4'-diisocyanate 2,2) - propane, 1,4-diisocyanatobenzene, 2,4- or 2,6-diisocyanatotoluene or mixtures of these isomers, 4,4'- or 2,4'-diisocyanatodiphenylmethane, 4,4'-diisocyanato- diphenyl (2,2) propane, p-xylylene diisocyanate and α, α, α ', α'-tetramethyl-m- or -p-xylylene diisocyanate and mixtures consisting of these compounds.

In addition to these simple polyisocyanates, those are also suitable which contain heteroatoms in the radical linking the isocyanate groups and / or have a functionality of greater than or equal to 2 NCO groups per molecule. Examples include polyisocyanates which contain carbodiimide groups, allophanate groups, isocyanurate groups, urethane groups, acylated urea groups, iminooxadiazinedione groups, uretdione groups or biuret groups, and also 4-isocyanato-methyl-1, 8-octane diisocyanate (nonane triisocyanate).

With regard to other suitable polyisocyanates, reference is made, for example, to DE-A 29 28 552, pp. 14-16. Mixtures of these compounds are also suitable.

Component (a2) preferably has an average molecular weight M _n of 400 to 5000, particularly preferably 800 to 2000. The hydroxyl number or amine number is generally 22 to 400, preferably 50 to 200 and particularly preferably 80 to 160 mg KOH / g ,

Suitable polyols (a2) are the compounds known from polyurethane chemistry, such as, for example, polyether polyols, polyester polyols, polycarbonate polyols, polyester amide polyols, polyamide polyols, epoxy resin polyols and their reaction products with CO ₂ , polyacrylate polyols and similar compounds. Such polyols, which can also be used in a mixture, are described, for example, in DE-A 20 20 905,

DE-A 23 14 513 and DE-A 31 24 784 and described in EP-A 0 120 466.

Instead of OH groups, the compounds of component (a2) can also contain primary or secondary amino groups (partially or completely) as NCO-reactive groups. Also suitable as component (a2) are aspartic acid esters of the above-mentioned molecular weight, as listed, for example, in EP-A 0 403 921, pp. 4-5. Such secondary amines can also be used as a mixture with the polyols.

Preferred polyols are the polyether and polyester polyols, particularly preferred are those which have only terminal OH groups and have a functionality of less than or equal to 3, preferably from 2.8 to 2.

Preferred polyesters are the known polycondensates of di- and optionally poly (tri, tetra) ols and mono-, di- and optionally poly (tri, tetra) carboxylic acids or hydroxycarboxylic acids or lactones. Instead of the free polycarboxylic acids, the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols can also be used to prepare the polyesters. Examples of suitable diols are ethylene glycol,

Butylene glycol, diethylene glycol, triethylene glycol, polyalkylene glycols such as polyethylene glycol, further propanediol, butanediol (1,4), hexanediol (1,6), neopentyl glycol or hydroxypivalic acid neopentyl glycol ester. Hexanediol (1,6), neopentyl glycol or hydroxypivalic acid neopentyl glycol esters are preferred compounds. Examples of polyols to be used here include trimethylolpropane, glycerol, erythritol, pentaerythritol, trimethylolbenzene or trishydroxyethyl isocyanurate.

Suitable di- or polycarboxylic acids are, for example, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexane dicarboxylic acid, adipic acid, azelaic acid, sebacic acid, glutaric acid, tetrachlorophthalic acid, maleic acid, fumaric acid, methyl acid, malaconic acid, malaconic acid, itaconic acid, malta acid, 3,3-diethylglutaric acid, 2,2-dimethylsuccinic acid, trimellitic acid or pyromellitic acid. Anhydrides of these acids can also be used if they exist. For the purposes of the present invention, the

Anhydrides consequently encompassed by the term "acid". It can too Monocarboxylic acids are used, provided that the average functionality of the polyol is greater than or equal to 2.

Suitable hydroxycarboxylic acids for the production of a polyester polyol with terminal hydroxyl are, for example, hydroxycaproic acid, hydroxybutyric acid,

Hydroxydecanoic acid, hydroxystearic acid and the like. Suitable lactones are e.g. Caprolactone, butyrolactone and the like.

Polyethene polyols which contain all or part of Al and / or A2 repeating units and also polyoxyethylene polyols, polyoxypropylene polyols, polyoxybutylene polyols or polytetrahydrofurans with terminal OH groups are very particularly preferred.

Furthermore, the polymers according to the invention can contain polyoxyalkylene ethers which are free from Al and / or A2 repeating units, but carry at least one hydroxyl or amino group per molecule, such as e.g. can be produced from an alcohol and from polyethylene oxide / polypropylene oxide blocks with a molecular weight of 400 to 4000.

In a preferred embodiment of the present invention, component (a2) contains, at least in part, an oligoester or polyester which contains mono- and / or polyunsaturated fatty acids. Suitable fatty acids are e.g. Coconut oil fatty acid, soybean oil fatty acid, safflower oil fatty acid, castor fatty acid, ricinic acid, peanut oil fatty acid, tall oil fatty acid or conjuene fatty acid. Suitable other monocarboxylic acids are e.g. Benzoic acid, tert-butylbenzoic acid, hexahydrobenzoic acid,

2-ethylhexanoic acid, isononanoic acid, decanoic acid or octadecanoic acid. Soybean oil fatty acid or a mixture of 70 to 100% by weight of soybean oil fatty acid and 0 to 30% by weight of benzoic acid is preferably used as the monocarboxylic acid. Thus, in addition to the allylic double bonds present in the structural units Al and / or A2, the polymer according to the invention preferably also contains C = C double bonds of mono- or polyunsaturated fatty acids. In a further preferred embodiment, component (a2) at least partially contains a polyol which additionally contains C = C double bonds in acrylic acid ester and / or methacrylic ester units A3) of the formula (III)

CH CR— C = O (III)

having.

Polyester acrylates containing hydroxyl groups and having an OH content of 30 to 300 mg KOH / g are preferably used. A total of 7 groups of monomer components can be used in the preparation of the hydroxy-functional polyester acrylates:

1. (cyclo) alkanediols, e.g. dihydric alcohols with (cyclo) aliphatically bound hydroxyl groups in the molecular weight range 62 to 286, such as ethanediol, 1,2- and 1,3-propanediol, 1,2-, 1,3- and 1,4-butanediol, 1,5-pentanediol , 1, 6-hexanediol, neopentyl glycol, cyclohexane-l, 4-dimethanol, 1,2- and 1,4-cyclohexanediol, 2-ethyl-2-butylpropanediol, diols containing ether oxygen, such as, for example Diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene, polypropylene or polybutylene glycols with a maximum molecular weight of 2000, preferably 1000 and particularly preferably 500. Reaction products of the aforementioned diols with ε-caprolactone or other lactones can also be used as diols Get involved.

2. Trihydric and higher alcohols in the molecular weight range 92 to 254, such as glycerol, trimethylolpropane, pentaerythritol, dipentaerythritol and Sorbitol or polyethers started on these alcohols, such as the reaction product of 1 mol of trimethylolpropane with 4 mol of ethylene oxide.

3. Mono alcohols such as Ethanol, 1- and 2-propanol, 1- and 2-butanol, 1-hexanol, 2-ethylhexanol, cyclohexanol and benzyl alcohol.

4.Dicarboxylic acids in the molecular weight range from 104 to 600 and / or their anhydrides, such as e.g. Phthalic acid, phthalic anhydride, isophthalic acid, tetrahydrophthalic acid, tetra-hydrophthalic anhydride, hexahydrophthalic acid, hexahydrophthalic anhydride, cyclohexanedicarboxylic acid, maleic anhydride, fumaric acid, malonic acid, succinic acid, succinic acid anhydride, dicarboxylic acid, dicarboxylic acid, dicarboxylic acid, adisodic acid, adisodic acid adisodic acid, dicarboxylic acid, dicarboxylic acid, dicarboxylic acid, dicarboxylic acid

5. Highly functional carboxylic acids or their anhydrides such as Trimelliphic acid and trimellitic anhydride.

6. monocarboxylic acids, e.g. Benzoic acid, cyclohexane carboxylic acid, 2-ethylhexanoic acid, caproic acid, caprylic acid, capric acid, lauric acid, natural and synthetic fatty acids.

7. Acrylic acid, methacrylic acid or dimeric acrylic acid.

Particularly preferred hydroxyl-containing polyester acrylates contain the reaction product of at least one component from group 1 or 2 with at least one component from group 4 or 5 and at least one component from group 7.

It is also possible, in the polyester acrylates to be used according to the invention, to also be generally known from the prior art, for example in Progress in

Organic Coatings, 9 (1981), 291-296, described dispersing To incorporate groups. For example, proportionate polyethylene glycols and / or methoxypolyethylene glycols can be incorporated as the alcohol component. Examples of compounds which may be mentioned are polyethylene glycols started on alcohols, polypropylene glycols and their block copolymers and the monomethyl ethers of these polyglycols. Polyethylene glycol 1500 and / or polyethylene glycol is preferred.

500 monomethyl ether.

It is also possible to react some of the (excess) carboxyl groups, in particular that of (meth) acrylic acid, with mono-, di- or polyepoxides. Preferred epoxies are epoxides (glycidyl ether) of monomeric, oligomeric or polymeric bisphenol-A, bisphenol-F, hexanediol and / or butanediol. This reaction can be used in particular to increase the OH number of the polyester acrylate, since one OH group is formed in each case in the epoxy-acid reaction.

The production of polyester acrylates in the sense of the present invention is described, for example, in DE-A-4 040 290, DE-A-3 316 592 and PKT Oldring (Ed.), Chemistry & Technology of UV & EB Formulations For Coatings, Inks & Paints , Vol. 2, 1991, SITA Technology, London, pp. 123-135.

The acid number of the polyester acrylates is less than or equal to 20 mg KOH / g, preferably less than or equal to 10 mg KOH / g and particularly preferably less than or equal to 5 mg KOH / g.

Alternatively, known epoxy acrylates containing hydroxyl groups, polyether acrylates containing hydroxyl groups or polyurethane acrylates containing hydroxyl groups with OH contents of 20 to 300 mg KOH / g can also be used, as well as their

Mixtures with one another and mixtures with unsaturated polyesters containing hydroxyl groups and mixtures with polyester acrylates or mixtures with unsaturated polyesters containing hydroxyl groups with polyester acrylates. The polymer according to the invention thus preferably contains (meth) acrylic ester double bonds in addition to the allylic double bonds present from the structural units in Al and / or A2.

Compounds suitable as component (a3) are those which have at least one group which is reactive toward isocyanate groups and at least one ionic and / or potentially ionic group. Potentially ionic are understood to be those groups which are capable of forming an ionic group. Ionic or potentially ionic groups are, for example, carboxyl, sulfonic acid, phosphoric acid or phosphonic acid groups or their corresponding anions. Carboxyl (at) and / or sulfone (at) groups are preferred. Suitable components (a3) are described, for example, in US Pat. No. 3,412,054, columns 1 and 2, US Pat. No. 3,640,924, column 3 and in DE-A 26 24 442, pages 25 to 26, to which reference is made here.

Also suitable are compounds (a3) containing amino groups, such as, for example, α, δ-diaminovaleric acid or 2,4-diamino-toluenesulfonic acid (5). Mixtures of these compounds (a3) can also be used.

Particularly preferred compounds (a3) are alcohols which have at least one

Carboxyl group, preferably contain 1 to 3 carboxyl groups per molecule. Examples include hydroxypivalic acid, dihydroxycarboxylic acids, such as α, α-dialkylolalkanoic acids, in particular α, α-dimethylolalkanoic acids, such as 2,2-dimethylolacetic acid, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylol pentanoic acid, dihydroxysuccinic acid, also polyhydroxy acids, such as gluconic acid. 2,2-Dimethylolpropionic acid is very particularly preferred.

The low molecular weight polyols and / or secondary polyamines (a4) optionally used to construct the polymers according to the invention generally stiffen the polymer chain. They have a molecular weight of 62 to 400, preferably from 62 to 200 and can contain ahphatic, alicychic or aromatic groups.

Suitable components (a4) are low molecular weight polyols with up to about 20 carbon atoms per molecule, e.g. Ethylene glycol, diethylene glycol, 1,2-

Propanediol, 1,3-propanediol, 1,4-butanediol, 1,3-butylene glycol, cyclohexanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol, bisphenol A (2,2-bis (4-hydroxyphenyl) propane) , hydrogenated bisphenol A (2,2-bis (4-hydroxycyclohexyl) propane) and aspartic acid esters, as described in EP-A 0 403 924, and mixtures thereof. Triols such as trimethylolpropane and / or glycerin can also be used. Also suitable are polyols which contain a maximum of 5 epoxybutene units (A1 / A2) started on water, short-chain polyols or polyamines and have an average molecular weight of less than 400.

The polymer according to the invention can optionally also contain building blocks (a5) which are located at the chain ends and terminate them, so-called chain stoppers.

Suitable components (a5) are derived from mono-functional compounds which react with NCO groups, e.g. Monoamines, preferably mono-secondary amines or monoalcohols. Examples include methylamine, ethylamine, propylamine, butylamine, octylamine, laurylamine, stearylamine, isononyloxypropylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, N-methylaminopropylamine, diethyl (methyl) aminopropylamine, morpholine, piperidine or their substituted derivatives. Amidamines from diprimary amines and monocarboxylic acids, monoketimines from diprimary amines, primary / tertiary amines, such as N, N-dimethylaminopropylamine.

Likewise suitable components (a5) are mono-hydroxy-functional esters of acrylic and / or methacrylic acid, so-called (meth) acrylates. Examples of such compounds are the mono- (meth) acrylates of dihydric alcohols, such as ethanediol, the isomeric propanediols and butanediols or (meth) acrylates of polyhydric alcohols, such as, for example, trimethylolpropane, glycerol and pentaerythritol, which on average contain a free hydroxyl group.

Preferred compounds (a5) are those which have active hydrogen

Contain NCO groups of different reactivity. These are, for example, compounds which, in addition to a primary amino group, also contain secondary amino groups or, in addition to an OH group, also COOH groups or, in addition to an amino group (primary or secondary), also OH groups, the latter being preferred. Examples include primary / secondary amines, such as 3-amino-1-methylamino-propane, 3-amino-1-ethylaminopropane, 3-amino-1-cyclohexylaminopropane, 3-amino-1-methylaminobutane, mono-hydroxycarboxylic acids, such as hydroxyacetic acid, Lactic acid or malic acid, furthermore alkanolamines such as N-aminoethylethanolamine, ethanolamine, 3-aminopropanol, neopentanolamine and particularly preferably diethanolamine. Aspartic acid esters based on the abovementioned are also suitable

Amino alcohols as mentioned in EP-A 0 743 333.

If appropriate, the polymer according to the invention can also contain building blocks (a6) which are derived from so-called chain extenders. As such, there are the known, preferably difunctional, NCO groups reactive and preferred

Compounds in question which are not identical to (a2), (a3), (a4) and (a5) and mostly have average molecular weights less than 400. Examples include water, hydrazine, adipic dihydrazide, poly (di) amines, such as ethylenediamine, diethylenetriamine, dimethylethylenediamine, diaminopropane, hexamethylenediamine, isophoronediamine, 4,4'-diaminodicyclohexylmethane, which can also carry substituents such as OH groups , and mixtures of the components mentioned. Such polyamines are disclosed, for example, in DE-A 36 44 371.

The preparation of the polymers according to the invention is described in the prior art, for example in EP-A 0 355 682, EP-A 0 427 028 or DE-A 39 01 190. For example, the preparation can be carried out in such a way that an isocyanate-functional prepolymer is first produced and an OH- and / or NH-functional compound is obtained in a second reaction step by reaction with compounds (a5) and / or (a6) , as disclosed for example in EP-A 0 355 682. However, the preparation can also take place in such a way that the one containing OH groups

Polyurethane resin is formed directly by reacting components (al) to (a6), e.g. described in EP-A 0 427 028.

The polymer A) according to the invention is preferably prepared in such a way that first a polyurethane prepolymer is formed from the components (a1, polyisocyanates), (a2, polyols) and optionally component (a4, low molecular weight polyols) and components (a3) manufactures, which contains on average at least 1.7, preferably 2 to 2.5 free isocyanate groups per molecule and then then completely or partially reacts this prepolymer with the components (a5) and / or (a6) in a non-aqueous system.

The polyisocyanate is used in excess in the process according to the invention over the polyols (a2) to (a4), so that a product with free isocyanate groups results. These isocyanate groups are terminal and / or pendant, preferably terminal. The amount of polyisocyanate is expediently so large that the equivalent ratio of isocyanate groups to the total number of OH groups in the polyols (a2) to (a4) is 1.05 to 2.0, preferably 1.1 to 1.6.

The prepolymer is normally prepared at temperatures of 40 ° to 140 ° C., depending on the reactivity of the isocyanate used. Suitable catalysts, as are known to the person skilled in the art for accelerating the NCO-OH reaction, can be used to accelerate the urethanization reaction. Examples are tert. Amines such as triethylamine, organotin compounds such as dibutyltin oxide, dibutyltin dilaurate or tin bis (2-ethylhexanoate) or other organometallic compounds. The urethanization reaction is preferably carried out in the presence of solvents which are inactive towards isocyanates. Solvents which are compatible with water, such as ethers, ketones and esters, and N-methylpyrrolidone, are particularly suitable for this. The amount of this solvent advantageously does not exceed 25% by weight and is preferably in the range from 5 to 15

% By weight, based in each case on the sum of polyurethane resin and solvent. The polyisocyanate can be added quickly to the solution of the other components.

The prepolymer or its solution is then reacted with the compound according to (a5) and / or (a6), the temperature advantageously being in the range from 0 ° to 90 ° C., preferably from 20 ° to 60 ° C., until the NCO Content in the prepolymer has practically dropped to zero. For this purpose, the compound (a5) is used in a deficit or in a slight excess, the amounts mostly being 40 to 110% by weight, preferably 60 to 105% by weight, of the required stoichiometric

Amount. If less reactive diisocyanates are used to prepare the prepolymer, this reaction can also take place in water at the same time as the neutralization. A portion of the (non-neutralized) COOH groups, preferably 5 to 30% by weight, can optionally be reacted with difunctional compounds reactive with COOH groups, such as diepoxides.

Alternatively, the prepolymer can also be reacted with (a5) in part (based on the isocyanate content) before the remaining isocyanate groups are reacted completely or in part with component (a6) after the dispersion. The neutralization of the carboxyl groups can take place both before the dispersing step by adding the neutralizing agent to the prepolymer and during the dispersing step by adding the neutralizing amine to the dispersing water.

The polymer A) according to the invention can also be prepared by reacting components (a1) to (a6) in a direct reaction to give an OH-functional one Resin. The reaction conditions correspond to the conditions described for the preparation of the prepolymer containing NCO groups. Such a method is described, for example, in EP-A 0 427 028.

A further possibility for the production of the polyurethane polymer according to the invention consists of resins containing COOH and / or SO ₃ H groups, which additionally contain one or more groups reactive with isocyanate, via di- or polyisocyanates with polyether alcohols, which contain at least a proportion of repeating units Al and / or contain A2 to implement. Resins suitable for this purpose are, for example, vinyl polymers, polyesters, epoxies or hybrid resins (for example acrylate-grafted polyesters or polyurethanes), as are known from the prior art.

Tertiary amines are particularly suitable for neutralizing the resulting product containing COOH and / or SO ₃ H groups, for example trialkylamines having 1 to 12, preferably 1 to 6, carbon atoms in each alkyl radical. Examples are trimethylamine,

Triethylamine, methyldiethylamine, tripropylamine and diisopropylethylamine. The alkyl radicals can, for example, also carry hydroxyl groups, as in the case of the dialkylmonoalkanol, alkyldialkanol and trialkanolamines, e.g. Dimethylethanolamine, which preferably serves as a neutralizing agent. Inorganic bases, such as ammonia or sodium or

Potassium hydroxide can be used. The neutralizing agent is usually used in a molar ratio to the acid groups of the prepolymer from 0.3: 1 to 1.3: 1, preferably from 0.5: 1 to 1: 1.

The neutralization of the COOH or S0 ₃ H groups can be done before, during or in

Follow up to the urethanization reaction. As a rule, the neutralization step is carried out between room temperature and 100 ° C., preferably from 40 to 80 ° C. It can be carried out in any manner, for example by adding the water-containing neutralizing agent to the polyurethane resin or vice versa. However, it is also possible that the neutralizing agent is added first Add polyurethane resin and only then the water. In general, solids contents of 20 to 70% by weight, preferably 30 to 50% by weight, are obtained in this way.

The present invention also relates to aqueous dispersions

(A) 20 to 70% by weight, preferably 25 to 50% by weight, of at least one water-dilutable polymer containing urethane groups according to the invention,

(B) 0 to 20% by weight, preferably 0-10% by weight, of organic cosolvents and

(C) 10 to 70% by weight, preferably 30 to 60% by weight of water.

A mixture of several polymers (A) according to the invention can also be used.

Suitable organic cosolvents (B) are the conventional paint solvents known per se, such as, for example, ethyl acetate, butyl acetate, ethylene glycol monomethyl or ethyl ether acetate, 1-methoxypropyl-2-acetate, 3-methoxy-n-butyl acetate, acetone, 2 -Butanone, 4-methyl-2-pentanone, cyclohexanone, toluene, xylene, chlorobenzene, white spirit, mixtures which contain above all more highly substituted aromatics, as described, for example, under the names Solvent Naphtha, Solvesso ^® (Exxon Mobil Chem. Comp., Houston), Cypar ^® (Shell Chemicals, UK), cyclo Sol ^® (Shell Chem.), Tolu

Sol ^® (Shell Chem.), Shellsol ^® (Shell Chem.) Are commercially available, carbonic acid esters such as dimethyl carbonate, diethyl carbonate, 1, 2-ethylene carbonate and 1,2-propylene carbonate, lactones such as ß-propiolactone, γ-butyrolactone, ε -Caprolactone and ε-methylcaprolactone, but also solvents such as propylene glycol diacetate, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, diethylene glycol ethyl and butyl ether acetate, N-methylpyrrolidone and N-methylcaprolactam, or any mixture of such solvents.

The organic cosolvents (B) can be added to the water-dilutable polymer containing urethane groups according to the invention or its dispersion subsequently or during production. Usually at least part of the organic Solvent added during the preparation or dispersion of the polymer according to the invention. For the production of low-co-or low-co-dispersions, it is also possible to use auxiliary solvents during the production process which are removed in a later step.

When used as a coating agent, the dispersions containing the water-dilutable, urethane-containing polymers according to the invention are used either alone or in combination with other aqueous binders. Such aqueous binders can e.g. B. of polyester, polyacrylate, polyepoxide or polyurethane polymers. The combination with radiation-curable binders, e.g. in EP-A-0 753 531 is possible. The dispersions containing the polymers according to the invention can be used as such or in combination with the auxiliaries and additives known from coating technology, such as e.g. Pigments, fillers and paint aids e.g. Anti-settling agents, defoaming and / or wetting agents, leveling agents, reactive thinners,

Plasticizers, catalysts, auxiliary solvents or thickeners can be used to produce coatings.

The present invention also relates to coating compositions comprising the water-dilutable polymers containing urethane groups according to the invention.

The dispersions containing the polymers according to the invention are used as binders for the production of coatings. Such coatings can be applied to any substrates, e.g. Wood, metal, plastic, paper, leather, textiles, felt, glass or mineral substrates.

The production of oxidatively drying aqueous coatings is preferred, characterized in that the coating agent contains the water-thinnable, urethane group-containing polymers (A) as a binder.

Siccatives can be added to accelerate the oxidative crosslinking. An advantage of the dispersions which contain the polymers (A) according to the invention is that the production of fast-drying coatings is possible without the addition of siccatives.

Likewise preferred is the production of UV-curing coatings, characterized in that the coating agent contains, as a binder, the water-dilutable polymers (A) according to the invention (A) and one or more photoinitiators.

The UV-curing coatings produced in this way are distinguished from the UV-curing lacquers of the prior art by particularly good shadow curing. In particular when coating shaped articles, in contrast to flat articles, the problem frequently arises that UV-curing coatings are soft, sticky and / or not resistant in places where no or only a small dose of UV light acts. Post-curing via a second mechanism that is not dependent on UV light is advantageous here.

Suitable photoinitiators are e.g. aromatic ketone compounds such as benzophenones, alkylbenzophenones, 4,4'-bis (dimethylamino) benzophenone (Michlers

Ketone), anthrone and halogenated benzophenones. Also suitable are acylphosphine oxides, such as. B. 2,4,6-trimethyl-benzoyl-diphenylphosphine oxide, phenyl-glyoxylic acid ester, anthraquinone and its derivatives, benzil ketals and hydroxyalkylphenones. Mixtures of these compounds can also be used.

The coating compositions comprising the polymers (A) according to the invention can be applied in known ways, for example by brushing, pouring, knife coating, spraying, spraying, spinning, rolling or dipping. The paint film can be dried at room temperature or elevated temperature, but also by baking at up to 200 ° C. Drying is preferably carried out at room temperature or only slightly above. Are UV-curing constituents in the disper- contain ions, the drying process can also include exposure to UV light.

During the drying of the coatings, water and, if appropriate, further solvent are first removed from the coating using known methods, followed by irradiation with UV light and finally oxidative drying.

The present invention also relates to substrates coated with coating compositions comprising the water-dilutable polymers (A) containing urethane groups.

Examples

All percentages are percentages by weight.

Example 1

1022 g of isophthalic acid, 6900 g of soybean oil fatty acid, 1278 g of benzoic acid, 3353 g of pentaerythritol and 911 g of phthalic anhydride are weighed into a 151 reaction vessel with stirrer, heating device and water separator with cooling device and heated to 140 ° C. in one hour under nitrogen. In a further 8 hours, the mixture is heated to 220 ° C. and condensed at this temperature until an acid number of less than 3 is reached. The polyester resin thus obtained has a viscosity (determined as the flow time of a 75% strength solution of the polyester in xylene in a DLN 4 beaker at 23 ° C.) of 105 seconds and an OH number of 175 mg KOH / g.

607 g of the polyester described above are placed in a 41-reaction vessel with a cooling, heating and stirring device and together with 58 g of dimethylol propionic acid, 150 g of a linear polyether diol with an OH number of 75 mg KOH / g, which is characterized by ring-opening Polymerization of 3,4-epoxy-1-butene with 3,4-dihydroxy-1-butene was prepared as a starter, 75 g of N-methylpyrrolidone, 75 g

Dipropylene glycol dimethyl ether and 22 g triethylamine heated to 80 ° C and homogenized for 30 min. 185 g of l-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI) are then added with vigorous stirring, the mixture is heated to 100 ° C. (using the exothermic nature of the reaction) and the mixture is kept at this temperature for as long as possible until no more NCO groups can be found.

The linear polyether diol is obtained by adding a solution of 37 g (0.42 mol) of 3,4-di-hydroxy-1-butene, 600 g of 3,4-epoxy-1-butene and 1 ml of trimethyl orthobenzoate to 50 g of a DMC Catalyst according to EP-A 0 700 049, dissolved in 5 ml of toluene, at 120 ° C. The rate of addition was chosen so that the

Reaction temperature does not exceed 155 ° C. The reaction temperature will then kept at 150 ° C until the 3,4-epoxy-1-butene has completely reacted. The product has a molecular weight of 2074 mol determined by GPC and a polydispersity of M _w / M _n = 1.15.

Then is distilled at 95 ° C with 1000 g of dist. Dispersed water and adjusted with water and triethylamine to a viscosity of 930 mPas (D = 40 s ^"1 , 23 ° C).

The aqueous urethane-modified polyester resin obtained in this way has an acid number of 26 mg KOH / g, an average particle size of 150 nm and a solids content of 45.6%.

Example 2

607 g of the polyester from Example 1 are placed in a 41 reaction vessel with a cooling, heating and stirring device and together with 58 g of dimethylolpropionic acid,

150 g of a linear polyether diol with an OH number of 73 mg KOH / g and a number average molecular weight of 1300, which by ring-opening polymerization of a mixture of 3,4-epoxy-1-butene and propylene oxide (molar ratio 50:50) with tripropylene glycol as Starter was prepared, 150 g of N-methylpyrrolidone and 22 g of triethylamine were heated to 80 ° C. and homogenized for 30 minutes. 185 g of l-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI) are then added with vigorous stirring, and the mixture is heated to 100 ° C. (using the exothermic nature of the reaction) and the mixture is kept as long this temperature until no more NCO groups can be determined.

The linear polyether diol was prepared according to Example 1, except that the reaction of the catalyst, starter, propylene oxide and 3,4-epoxy-1-butene was carried out in an autoclave.

Then at 95 ° C with 1000 g of dist. Dispersed water and adjusted with water and triethylamine to a viscosity of 640 mPas (D = 40 s ^"1 , 23 ° C). The aqueous urethane-modified polyester resin thus obtained has an acid number of 26 mg KOH / g, an average particle size of 170 nm and a solids content of 45.8%.

Example 3

612 g of the polyester from Example 1 are placed in a 41 reaction vessel with a cooling, heating and stirring device and together with 58 g of dimethylolpropionic acid, 150 g of a polyether triol with an OH number of 56 mg KOH / g and a number average molecular weight of 4200, which was prepared by ring-opening polymerization of a mixture of 3,4-epoxy-1-butene and propylene oxide (molar ratio 50:50) with a propylene oxide polyether of OH number 238 started on glycerol, 150 g of N-methylpyrrolidone and 22 g of triethylamine are heated to 80 ° C. and homogenized for 30 minutes. Then 180 g of 1-isocyanato

3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI) with vigorous stirring, heats up (using the exotherm of the reaction) to 100 ° C and keeps the mixture at this temperature until no more NCO groups are found to let.

Then is distilled at 95 ° C with 1000 g of dist. Dispersed water and adjusted with water and triethylamine to a viscosity of 1070 mPas (D = 40 s ^"1 , 23 ° C).

The aqueous urethane-modified polyester resin thus obtained has an acid number of 27 mg KOH / g, an average. Particle size of 200 nm and a solids content of 46.1%. Example 4

602 g of the polyester from Example 1 are placed in a 41 reaction vessel with a cooling, heating and stirring device and together with 58 g of dimethylolpropionic acid, 150 g of the linear polyether diol of OH number 75 mg used in Example 1

KOH / g, 150 g of N-methylpyrrolidone and 22 g of triethylamine are heated to 80 ° C. and homogenized for 30 minutes. Then 190 g of l-isocyanato-3,3,5-trimethyl-5-isocyanatomefethylcyclohexane (IPDl) are added with vigorous stirring, the mixture is heated to 100 ° C. (using the exothermic nature of the reaction) and the mixture is kept at this temperature for as long as possible until no more NCO groups can be found.

Then at 95 ° C with 1000 g of dist. Dispersed water and adjusted with water and triethylamine to a viscosity of 620 mPas (D = 40 s ^"1 , 23 ° C).

The aqueous urethane-modified polyester resin thus obtained has an acid number of

26 mg KOH / g, an average particle size of 240 nm and a solids content of 45.7%.

Example 5

1347 g of trimethylolpropane, 5631 g of soybean oil fatty acid, 3722 g of phthalic anhydride and 2614 g of neopentyl glycol are weighed into a 151 reaction vessel with stirrer, heating device and water separator with cooling device and heated to 140 ° C. in one hour under nitrogen. In a further 8 hours, the mixture is heated to 220 ° C. and condensed at this temperature until an acid number of less than 3 is reached. The polyester resin thus obtained has a viscosity (determined as the flow time of an 80% solution of the polyester in xylene in a DIN 4 cup at 23 ° C.) of 59 seconds and an OH number of 46 mg KOH / g.

In a 41-reaction vessel with a cooling, heating and stirring device, 1410 g of the polyester precursor described above and together with 151 g of dimethylol propionic acid, 390 g of the linear polyether diol of OH number 75 mg KOH / g and 650 g of N-methylpyrrolidone described in Example 1, heated to 100 ° C. and homogenized for 30 minutes. The mixture is then cooled to 70 ° C. and 650 g of l-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI) are added with vigorous stirring. The reaction mixture is kept under stirring at this temperature until an NCO content of

2.5% is reached (approx. 10 - 15 h). Then 114 g of triethylamine are stirred in homogeneously.

In a 61-reaction vessel with a cooling, heating and stirring device, 2080 g of the NCO prepolymer thus obtained, heated to 55 ° C., are then added

Stir within 5 - 10 min in 1395 g of distilled water preheated to 30 ° C. Water. A mixing temperature of approx. 40 ° C is reached. The crude dispersion is cooled to about 30 ° C. and a solution of 36.4 g of ethylenediamine in 815 g of distilled water is then added with stirring. Water too. The mixture is stirred for a further 2 hours at 35-40 ° C. and then adjusted to a viscosity of 2300 mPas (D = 40 s ^{* 1} , 23 ° C.) with water and triethylamine.

The polyurethane dispersion produced in this way has an acid number (100%) of 25 mg KOH / g, an average particle size of 42 nm and a solids content of 37.2%.

Example 6 (comparative example):

Production of a fatty acid-based urethane-modified polyester dispersion

1126 g of the polyester precursor from Example 1 are placed in a 41 reaction vessel with a cooling, heating and stirring device and heated to 80 ° C. together with 87.5 g of dimethylolpropionic acid, 244 g of N-methylpyrrolidone and 33 g of triethylamine and 30 homogenized min. Then 286.5 g of l-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI) are added with vigorous stirring, the mixture is heated to 100 ° C. (using the exothermic nature of the reaction) and the mixture is kept as long as possible this temperature until no more NCO groups can be determined. Then 14.4 g of ethoxylated nonylphenol are added, dispersed in about 1400 g of water, homogenized and adjusted with water and triethylamine to a viscosity of 1100 mPas (D = 40 s ^"1 , 23 ° C.). The aqueous urethane-modified polyester resin obtained has an acid number of 27 mg KOH / g and a solids content of 45%.

Application example 1 (oxidatively drying topcoats):

The dispersions of Examples 1-5 and Comparative Example 6 are ^® with Octasoligen Co 7 aqua (cobalt siccative, 50% in water, Borchers GmbH) corresponding to a concentration of 0.06% Co metal on the solid resin (binder 100% ig), diluted with water to a run-out time of approx. 30 seconds (DIN 4 cup, 23 ° C) and applied with a squeegee to degreased glass plates or degreased steel sheets (dry film thickness 50 μm). After drying at room temperature, trouble-free paint films with good results are obtained

Property level.

Application properties of oxidatively drying lacquers according to Application Example 1 based on the dispersions from Examples 1 - 6:

*: Ratings from 0 - 5 possible; 0 = film undamaged, 5 = film very badly damaged Table 1 shows that the dispersions, prepared in accordance with Examples 1-5 according to the invention, have improved water resistance. In Comparative Example 6, there is both a clear drop in gloss after 3 hours and a slight wrinkle after 8 hours, and after 24 hours a strong wrinkle of the film, which is also no longer reversible. The varnishes, based on Examples 1 to 5, however, show significantly better results.

Example 7

In a 2 1 four-necked flask with stirring device, reflux condenser and internal thermometer, 163.8 g of the linear polyether diol of OH number 75 mg KOH / g described in Ex. 1, 181 g of a polytetramethylene ether glycol with an OH number of 56 mg KOH / g, 37.2 g of dimethylolpropionic acid, 18.3 g of 1,6-hexanediol and 97.4 g of N-methylpyrrolidone were mixed together and heated to 70 ° C. before 275.5 g

Desmodur ^® W (product from Bayer AG, Leverkusen) can be added quickly. The temperature is kept at 80 ° C. before it is reduced from 4.4% to 70 ° C. when the NCO content of the prepolymer is reached and 19.6 g of triethylamine are added. After 10 minutes, 500 g of the prepolymer are placed in a second, equipped with a stirrer and filled with 670 g of water (20 ° C.) within 5 minutes

Piston transferred. After 10 minutes of intensive stirring, within 5 minutes. a mixture of 5.2 g of hydrazine hydrate, 8.4 g of ethylenediamine and 74.4 g of water was added. The mixture is then stirred at 40 ° C. until no more NCO can be detected in the dispersion. The polyurethane dispersion has an average particle size of 69 nm and a solids content of 35.3%.

A clearcoat consisting of 87.9% of this polyurethane dispersion, 3.0% butyl glycol, 1.0% Byk ^® 028 (defoamer, Byk Chemie, Wesel), 0.2% Byk ^® 024 (defoamer, Byk) , 0.2% Byk ^® 346 (substrate wetting additive, Byk), 0.5% Byk ^® 381 (leveling additive, Byk), 0.2% TS ^® 100 (matting agent,

Degussa AG, Frankfurt), 2.0% Aquamat ^® 263 (wax / slip additive, Byk) and 2.0% Acrysol ^® RM 8 (5%, thickeners, Fa. Rohm & Haas, Philadelphia) will microns with a doctor blade with a gap width of 200 knife-coated onto a glass plate and dried at room temperature 7d. A clear, glossy film with a pendulum hardness (drying for 14 days at room temperature) of 115 seconds is obtained.

Example 8

163.8 g of the linear polyether diol of the OH number 73 mg KOH / g described in Example 2 and 181 g of a polytetramethylene ether glycol with an OH- are in a 2 1 four-necked flask with stirring device, reflux condenser and internal thermometer.

Number of 56 mg KOH / g, 37.2 g dimethylolpropionic acid, 18.3 g 1,6-hexanediol and 97.4 g N-methylpyrrolidone were mixed together and heated to 70 ° C. before 275.5 g Desmodur W (product of the Bayer AG, Leverkusen) can be added quickly. The temperature is kept at 80 ° C. before it is reduced from 4.4% to 70 ° C. when the NCO content of the prepolymer is reached and 19.6 g of triethylamine are added. After 10 minutes, 500 g of the prepolymer are transferred within 5 minutes to a second 2 l flask equipped with a stirrer and filled with 670 g of water (20 ° C.). After 10 minutes of intensive stirring, within 5 minutes. a mixture of 5.2 g of hydrazine hydrate, 8.4 g of ethylenediamine and 74.4 g of water was added. Then the mixture is stirred at 40 ° C. until none in the dispersion

NCO is more detectable. The polyurethane dispersion has an average particle size of 70 nm and a solids content of 35.3%.

A clear lacquer consisting of 87.9% of this polyurethane dispersion, 3.0% butyl glycol, 1.0% Byk ^® 028 (defoamer, from Byk), 0.2% Byk ^® 024 (defoamer, from Byk),

0.2% Byk ^® 346 (substrate wetting additive, Byk), 0.5% Byk ^® 381 (leveling additive, Byk), 0.2% TS ^® 100 (matting agent, Degussa,), 2.0% Aquamat ^® 263 (wax / slip additive, from Byk) and 2.0% Acrysol ^® RM 8 (5%, thickener, from Rohm & Haas) are knife-coated onto a glass plate with a doctor blade with a gap width of 200 μm and 7d dried at room temperature. You get a clear, shiny film with a pendulum hardness (drying 14 days at RT) of 80 seconds.

Example 9 Oligomer precursor for Example 10

3200 g of castor oil and 1600 g of soybean oil and 2.4 g of dibutyltin oxide are weighed into a 51 reactor with a distillation attachment. A stream of nitrogen (5 l / h) is passed through the reactants. The mixture is heated to 240 ° C. within 140 minutes. After 7 h at 240 ° C is cooled. The OH number is 109 mg KOH / g, the acid number 2.5 mg KOH / g.

Example 10 (comparative example):

Production of a fatty acid-based polyurethane dispersion

339 g of polytetramethylene ether glycols with an OH number of 56 mg KOH / g, 248 g of the polyester oligomer precursor, 70 g of dimethylolpropionic acid, 34 g of 1,6-hexanediol and 34 g of N-methylpyrrolidone are heated to 70 ° C. and stirred until a clear solution is obtained. Then 516 g of Desmodur ^® W (Bayer AG, Leverkusen) are added and heated to 100 ° C. The mixture is stirred at this temperature until the NCO content is 4.1%. The mixture is then cooled to 70 ° C. and 52.6 g of triethylamine are added.

650 g of this solution are dispersed with vigorous stirring in 601 g of water, which is placed at a temperature of 30 ° C. After dispersion, stirring is continued for 5 minutes. A solution of 3.9 g of hydrazine hydrate and 10.2 g of ethylenediamine in 200 g of water is then added within 5 minutes. To completely react the isocyanate groups, the mixture is stirred at 45 ° C. until no more NCO groups can be detected. The polyurethane dispersion produced in this way has an average particle size of 60 nm and a solids content of 35%.

0.2% Byk ^® 346 (substrate wetting additive, Byk), 0.5% Byk ^® 381 (leveling additive, Byk), 0.2% TS ^® 100 (matting agent, Degussa), 2.0% Aquamat ^® 263 (wax / slip additive, Byk) and 2.0% Acrysol ^® RM 8 (5%, thickener, Rohm & Haas) is knife-coated onto a glass plate with a doctor blade with a gap width of 200 μm and 7d at Room temperature dried. A clear, glossy film with a pendulum hardness (drying for 14 days at room temperature) of 75 seconds is obtained.

Example 11 (according to the invention): UV-curing and oxidatively drying dispersion

In a 21 l reaction vessel with stirrer, internal thermometer and gas inlet (air stream 2 to 3 1 / h), 313.0 g of the polyester acrylate Laromer ^® PE 44F (polyester acrylate; BASF AG, Ludwigshafen, DE), OH content about 80 mg KOH / g, and 87.7 g of polyether diol of example 1, 21.0 g of dimethylolpropionic acid, 0.5 g of dibutyltin dilaurate, provided 172.2 g of acetone, 79.9 g Desmodur ^® I (isophorone diisocyanate, Bayer AG, Leverkusen, DE) and 39.4 g Desmodur ^® H (hexamethylene diisocyanate; Bayer AG, Leverkusen, DE) was added and heated such that constant acetone refluxing was obtained. The mixture is stirred at this temperature until the reaction mixture has an NCO content of 1.6% by weight. Then on

Cooled 40 ° C, and 15.8 g of triethylamine are quickly added. After 10 minutes, the reaction mixture is poured into 938.1 g of water at 18 ° C. with rapid stirring. After the dispersion has formed, 8.0 g of ethylenediamine in 23.5 g of water are added. After stirring for 30 minutes without heating or cooling, the product is distilled in vacuo (50 mbar, max. 50 ° C) until a solid of

38.6 wt .-% is reached. The viscosity of the dispersion was 24.7 s flow time in DLN 4 beaker, the pH was determined to be 8.6, and the mean particle size after laser correlation spectroscopy measurement (Zetasizer 1000, Malvern Instruments, Malvern, UK) was 60.0 nm.

Example of use 12

In a portion of the dispersion of the invention according to Example 11 1.5 wt .-% Irgacure ^® 500 (photoinitiator, Fa. Ciba, Lampertheim, DE) are stirred calculated on the solids content of the dispersion. After standing overnight, the dispersion is drawn onto a glass plate using a 150 μm bone doctor. The coated glass plate is stored for 40 minutes at room temperature. A clear, transparent and dry to the touch film is formed. The coated glass plate is then moved at a speed of 5 m / min under a medium pressure mercury lamp (power 80 W / cm lamp length). The film, UV-cured in this way, shows a König pendulum hardness of 59 minutes 30 minutes after irradiation. The pendulum hardness increases to 82 within 36 hours of storage at room temperature.

Claims

Patent claims

1. Water-dilutable polymer containing urethane groups with ionic and/or potentially ionic groups, characterized in that the polymer contains the repeating units (AI) of the formula (I) and/or (A2) of the formula (II)

CH=CH,

-CH— CH- -O CH— CH=CH— CH—

(I) (II) contains.

Water-dilutable polymer according to claim 1, characterized in that the repeating units AI, A2 or mixtures A1/A2 in the polymer in blocks

or in blocks mixed from both structural units with p repeat units, where n, m, p each represent integers from 3 to 100.

Water-dilutable polymer according to claims 1 or 2, characterized in that the polymer is a reaction product containing the components

(al) 5 to 80% by weight of polyisocyanates,

(a2) 10 to 80% by weight of polyols and/or polyamines of a medium

Molecular weight M _n of at least 400, (a3) 2 to 15% by weight of compounds that have at least one opposite

isocyanate group-reactive group and at least one ionic and/or potentially ionic group, (a4) 0 to 20% by weight of low molecular weight polyols and/or secondary ones

Polyamines, (a5) 0 to 20% by weight of chain stoppers,

(a6) 0 to 20% by weight of chain extenders which have at least two groups reactive towards isocyanate groups and from (a2),

(a3) and

(a4) are different.

4. Water-dilutable polymer according to claim 1, characterized in that it additionally contains C = C double bonds in structural units of monounsaturated or polyunsaturated fatty acids.

5. Water-dilutable polymer according to claim 1, characterized in that it additionally contains C = C double bonds in acrylic acid and / or methacrylic acid ester units A3 of the formula (III),

CH^CR—C (III)

having.

6. Water-dilutable polymer according to one or more of claims 1 to 5, characterized in that the polymer has a content of ionic and / or potentially ionic groups of 9 to 100 meq / 100g.

7. Water-dilutable polymer according to one or more of claims 1 to 6, characterized in that ionic and / or potentially ionic

Groups are carboxyl and/or sulfonic acid groups.

8. Water-dilutable polymer according to one or more of claims 1 to 7, characterized in that the polymer has a urethane group [NHCOO] content of 1 to 40% by weight.

9. Water-dilutable polymer according to one or more of claims 1 to 8, characterized in that the polymer has a content of structural units Aj and / or A ₂ of 2 to 80% by weight.

10. Containing aqueous dispersion

(A) 20 to 70% by weight of at least one water-dilutable, urethane group-containing polymer according to claim 1, (B) 0 to 20% by weight of organic co-solvents and

(C) 10 to 70% by weight water.

11. Coating agent containing a water-thinnable, urethane group-containing polymer according to claim 1.

12. A process for producing oxidatively drying coatings, characterized in that the coating agent contains water-thinnable, urethane group-containing polymers according to claim 1 as a binder.

13. A process for producing UV-curing coatings, characterized in that the coating agent contains water-thinnable, urethane group-containing polymers according to claim 1 as well as one or more photoinitiators as a binder.

14. Use of the water-thinnable, urethane group-containing polymers according to claim 1 for producing oxidatively drying coatings.

15. Use of the water-thinnable, urethane group-containing polymers according to claim 1 for producing UV-curing coatings.

6. Substrates coated with coating agents containing water-thinnable, urethane group-containing polymers according to claim 1.