WO2009141289A1

WO2009141289A1 - Water-emulsifiable polyisocyanates

Info

Publication number: WO2009141289A1
Application number: PCT/EP2009/055962
Authority: WO
Inventors: Harald Schäfer; Thomas Zech; Angelika Maria Steinbrecher
Original assignee: Basf Se
Priority date: 2008-05-20
Filing date: 2009-05-18
Publication date: 2009-11-26

Abstract

The present invention relates to new, water-emulsifiable polyisocyanates of low viscosity, to processes for preparing them and to their use.

Description

Water emulsifiable polyisocyanates

description

The present invention relates to novel low viscosity water emulsifiable polyisocyanates, to processes for their preparation and to their use.

DE-OS 2908844 describes modified with monofunctional polyethylene oxides polyisocyanates, wherein the ethylene oxide chain must have at least 5 ethylene oxide units.

The examples explicitly disclosed contain less than 5% by weight of a methanol-started polyethylene oxide of average molecular weight 650. The lower the content of the surface-active agent, the lower the gel time of the emulsions thus prepared, so that a low level of surfactant is recommended becomes.

The disadvantage is that polyisocyanates are less emulsifiable with low emulsifier.

EP 959087 A1 describes polyether-modified water-dispersible polyisocyanate mixtures in which the polyether chains are at least 60 mol% linked via allophanate groups with two polyisocyanates each composed of at least two diisocyanates.

In the examples disclosed explicitly methanol-initiated polyethylene oxides of molecular weight 350 or 500 in amounts of 9.1 and 12.2% by weight are used to achieve the water-dispersibility (cyclo) aliphatic polyisocyanates with a high degree of allophanatization.

Due to the high proportion of allophanate groups, the proportion of free isocyanate groups is reduced and the molecular weight is increased.

DE 19958170 A1 describes polyether-modified water-dispersible polyisocyanate mixtures in which the polyether chains are linked to 20 to 59 mol% via allophanate groups with two polyisocyanates each composed of at least two diisocyanates.

In the examples explicitly disclosed, methanol-started polyethylene oxides having a molecular weight of 350 or 500 in amounts of 15.4 and 14.0% by weight, respectively, are used to achieve water dispersibility of (cyclo) aliphatic polyisocyanates with a high degree of allophanatization. Due to the high proportion of allophanate groups, the proportion of free isocyanate groups is reduced and the molecular weight is increased.

No. 5,200,489 describes water-dispersible polyisocyanates of 1,6-hexamethylene diisocyanate which are modified to at least 10% by weight with a monohydroxy-functional polyether in which the ethylene oxide fraction has a molecular weight of 200 to 1,000.

In the explicitly disclosed examples, the water-dispersibility of an isocyanurate of 1 rats is investigated 6-hexamethylene diisocyanate having a viscosity of 3000 mPas at 20 ⁰ C, varying the amount and molecular weight of the polyether. Optimal results of the water dispersibility, based on the amount of the residue, are achieved at molar masses of 550 to 825 and amounts of 12.5 to 20% by weight. The viscosity of the product is not specified.

EP 206059 A2 describes polyisocyanates modified with monofunctional polyalkylene oxides, where the alkylene oxide chain must have at least 10 ethylene oxide units.

Polyisocyanates of various (cyclo) aliphatic isocyanates which are rendered water-dispersible with polyethylene oxide polyethers which have a molecular weight of not less than 840 and which are started on n-butanol or on heterocyclic alcohols are explicitly disclosed. The proportion of polyether alcohols in the polyisocyanate preparation is 1 to 12% by weight of ethylene oxide units arranged within polyether chains.

Ratgruppen The polyisocyanate used in the explicitly disclosed embodiments with isocyanurates have a low viscosity (polyisocyanate 1: 1700 mPas at 23 ⁰ C).

EP 540985 A1 describes polyisocyanates modified with monofunctional polyalkylene oxides, the alkylene oxide chain having on average from 5.0 to 9.9 ethylene oxide units.

In the examples explicitly disclosed, a polyethylene oxide of molar mass 350 initiated in methanol in amounts of 11.3% by weight is used for water-dispersing an isocyanate derivative of 1,6-hexamethylene diisocyanate.

The polyisocyanate with isocyanurate groups used in Example 1 has an average viscosity of 3000 mPas at 23 ⁰ C. The water-dispersible polyisocyanate obtained from this with a monofunctional polyethylene oxide polyether having 3050 mPas at 23 ⁰ C has a higher viscosity than the starting material. Higher-viscosity polyisocyanates with isocyanurate groups based on 1,6-hexamethylene diisocyanate have hitherto not been used as starting materials for water-dispersible polyisocyanates, since the skilled artisan expects an increase in viscosity in view of the viscosity development from the starting materials to the product, as in EP 540985 A1. In order to ensure easy incorporation of the water-dispersible polyisocyanates, low-viscosity products are desired. Alternatively, the viscosity would have to be reduced by the addition of solvents, but this is likewise undesirable because they have to be separated from the coating compositions and then give rise to a VOC load.

Since an important application of water-dispersible polyisocyanates is the use in paints, the water-dispersible polyisocyanates should preferably have a low color number.

The object of the present invention was to develop water-dispersible polyisocyanates which, with good water-dispersibility, have a low viscosity and, when used in coatings, give good coating properties.

The object was achieved by a process for the preparation of water-dispersible polyisocyanates containing isocyanurate groups by reacting a polyisobutene cyanate based on 1, 6-hexamethylene diisocyanate (A) having a viscosity at 20 ⁰ C (of at least 3500 mPas with at least one monofunctional polyalkylene oxide B), which has polymerized on the average 10.5 to 14 ethylene oxide units and wherein the proportion of the polyalkylene oxide (B) on water-dispersible polyisocyanate (sum of (A) and (B)) of 11 to 15% by weight.

Knowing the viscosity development of the products in the course of the reaction, as known from the prior art, it was unpredictable that higher-viscosity polyisocyanates (A) can also give water-dispersible polyisocyanates which are easily incorporated in water.

It has been found that water-dispersible polyisocyanates having acceptable viscosities can also be obtained from higher-viscosity isocyanurate group-containing polyisocyanates based on 1,6-hexamethylene diisocyanate. The coatings obtained with these water-dispersible polyisocyanates show good coating properties, for example a lower tendency to form cracks and / or bubbles.

The water-dispersible polyisocyanates obtained have a viscosity which is low enough to ensure good incorporability into, for example, aqueous polyols for two-component polyurethane coatings, so that it is possible to dispense with the use of solvents to reduce the viscosity or at least reduce their proportion. Component (A) is an isocyanurate group-containing polyisocyanate based on 1,6-hexamethylene diisocyanate.

For the present invention, it is possible to use both those diisocyanates which are obtained by phosgenation of the corresponding amines and those which can be obtained without the use of phosgene, ie. H. after phosgene-free process, are produced. According to EP-AO 126 299 (US Pat. No. 4,596,678), EP-A-126 300 (US Pat. No. 4,596,679) and EP-A-355 443 (US Pat. No. 5,087,739), for example, (cyclo) aliphatic diisocyanates, eg such as 1, 6-hexamethylene diisocyanate (HDI) are prepared by reacting the (cyclo) aliphatic diamines with, for example, urea and alcohols to (cyclo) aliphatic biscarbamic and their thermal cleavage into the corresponding diisocyanates and alcohols. The synthesis is usually carried out continuously in a cyclic process and optionally in the presence of N-unsubstituted carbamic acid esters, dialkyl carbonates and others from the

Reaction process recycled by-products. Thus obtained diisocyanates generally have a very low or even non-measurable proportion of chlorinated compounds, which is advantageous, for example, in applications in the electronics industry.

In one embodiment of the present invention, the isocyanates used have a total hydrolyzable chlorine content of less than 200 ppm, preferably less than 120 ppm, more preferably less than 80 ppm, most preferably less than 50 ppm, in particular less than 15 ppm and especially less than 10 ppm. This can be measured, for example, by ASTM D4663-98. Of course, it is also possible to use monomeric isocyanates having a higher chlorine content, for example up to 500 ppm.

Of course, mixtures of such monomeric isocyanates, which have been obtained by reacting the (cyclo) aliphatic diamines with, for example, urea and alcohols and cleavage of the obtained (cyclo) aliphatic biscarbamic, with such diisocyanates obtained by phosgenation of the corresponding amines, be used.

The polyisocyanates (A) to which the monomeric 1,6-hexamethylene diisocyanate is preferably oligomerized without incorporation of other diisocyanates other than 1,6-hexamethylene diisocyanate are generally characterized as follows:

The polyisocyanates of 1,6-hexamethylene diisocyanate having isocyanurate groups are, in particular, cyclic trimers of 1,6-hexamethylene diisocyanate or mixtures with their higher homologs containing more than one isocyanurate ring. The isocyanato-isocyanurates generally have NEN content of 10 to 28 wt .-%, in particular 15 to 25 wt .-% and an average NCO functionality of 2.6 to 8.

It may be a preferred embodiment to use high viscosity polyisocyanates having a functionality of greater than 3.8, more preferably having a functionality of from 4.0 to 7.0, most preferably having a functionality of from 4.2 to 6.5, such as they are described in EP 1091991.

There is also the less preferred possibility of copolymerizing isocyanurates with diisocyanates other than 1,6-hexamethylene diisocyanate, among these preferably (cyclo) aliphatic diisocyanates, more preferably isophorone diisocyanate or 4,4'-di (isocyanatocyclohexyl) methane.

In minor amounts, the isocyanurates of 1,6-hexamethylene diisocyanate may in particular comprise uretdione, urethane and / or allophanate groups.

In a preferred embodiment, the content of polyisocyanates is the urethane groups (calculated as - (- NH-CO -) - O- with a molecular weight of 59 g / mol) or allophanate groups (calculated as - (N (CONH-) (COO-) having a molecular weight of 101 g / mol) independently of one another contain in each case less than 5% by weight, preferably less than 3% by weight and more preferably less than 2% by weight, based on the sum of components (A) and (B).

The content of uretdione polyisocyanates is generally not more than 15% by weight, preferably not more than 10% by weight and more preferably not more than 3% based on the sum of components (A) and (B).

The polyisocyanate (A) is according to the invention to an isocyanurate-containing polyisocyanate or a mixture thereof, having a viscosity of at least 3500 mPa ^* s, preferably at least 3800, and most preferably at least 4000 mPas at 20 ⁰ C. An upper limit of the viscosity is not essential to the invention, for example it may be up to 10000 mPas, preferably up to 8000, more preferably up to 7000, very preferably up to 6,000 and especially up to 5,000 mPas at 20 ⁰ C.

In this document, the viscosity at 23 ⁰ C according to DIN EN ISO 3219 / A.3 in a cone-plate system with a speed gradient of 1000 S " ¹ indicated, unless otherwise noted.

Despite the use of relatively viscous polyisocyanates (A), low-viscosity and readily water-dispersible polyisocyanates which can be incorporated are obtained. The process for the preparation of the polyisocyanates (A) can be carried out as described in WO 2008/068198, there especially from page 20, line 21 to page 27, line 15, which is hereby incorporated by reference in the present application.

The reaction can be stopped, for example, as described in WO 2008/068198 described from page 31, line 19 to page 31, line 31 and the workup carried out as described there from page 31, line 33 to page 32, line 40, hereby by Reference is part of the present application.

The process for preparing the polyisocyanates (A) can also be carried out, for example, as described in international patent application WO 2008/116897, there especially from page 2, line 29 to page 21, line 29, which is hereby incorporated by reference in the present application.

Alternatively, the reaction can also be stopped, as described in WO 2005/087828 from page 11, line 12 to page 12, line 5, which is hereby incorporated by reference in the present application.

In the case of thermally unstable but also labile catalysts, it is possible to stop the reaction at lower temperatures by adding deactivators. Suitable deactivators are, for example, hydrogen chloride, phosphoric acid, organic phosphates, such as dibutyl phosphate or diethylhexyl phosphate, carbamates, such as hydroxyalkyl carbamate, preferably 2-hydroxyalkyl carbamate, or organic carboxylic acids. Particularly preferred are bis (2-ethylhexyl) phosphate, 2-hydroxyethyl carbamate and 2-hydroxypropyl carbamate

These compounds are added neat or diluted at the appropriate concentration necessary for reaction termination.

In the case of thermally labile catalysts, it is also possible to stop the reaction by heating the reaction mixture to a temperature above at least 80 ^° C., preferably at least 100 ^° C., more preferably at least 120 ^° C. The heating of the reaction mixture usually suffices , as required for the separation of the unreacted isocyanate by distillation in the workup.

Component (B) is polyalkylene oxide of the formula

R ¹ - [- CH ₂ -CH ₂ -O-] _k -H wherein

R ^{1 is} a C ¹ -C 4 -alkyl or C 2 -C 12 -cycloalkyl radical and k is, on average, a number from 10.5 to 14

mean.

It is understood, for example, as meaning methyl, ethyl, isopropyl, n-propyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, n-heptyl, n-octyl or 2- Ethylhexyl, Cs- to Ci2-cycloalkyl means cyclopentyl, cyclohexyl, cyclooctyl or cyclododecyl.

R ¹ is preferably a C ¹ - to C 6 -alkyl radical, particularly preferably a C ¹ - to C ⁴ -alkyl radical, very particularly preferably methyl, ethyl or n-butyl and in particular methyl.

The more carbon atoms the radical R ¹ has, the more nonpolar is the radical and thus reduces the hydrophilicity of the component (B).

Component (B) is preferably a pure polyethylene oxide without random admixtures of other polyalkylene oxides, for example propylene oxide. A small proportion of propylene oxide groups - [- CHb-CH (CHs) -] - in component (B) can then be tolerated if it does not substantially reduce the hydrophilicity of component (B).

The polyalkylene oxide polyether alcohols are generally prepared by alkoxylation of the starting compounds R ¹ OH in the presence of a catalyst, for example an alkali metal or alkaline earth metal hydroxide, oxide, carbonate or bicarbonate.

The production of the polyalkylene oxide polyether alcohols can also be carried out with the aid of multimex cyanide compounds, frequently also referred to as DMC catalysts, which have been known for a long time and are frequently described in the literature, for example in US Pat. No. 3,278,457 and in US Pat. No. 5,783,513.

The DMC catalysts are usually prepared by reacting a metal salt with a cyanometalate compound. To improve the properties of the DMC catalysts, it is customary to add organic ligands during and / or after the reaction. A description of the preparation of DMC catalysts can be found, for example, in US-A 3,278,457.

Typical DMC catalysts have the following general formula: M ¹ a [M ² (CN) _b ] d • f MV < _k • h (H ₂ O) eL • zP

wherein

M ^{1 is} a metal ion selected from the group consisting of Zn ²⁺ , Fe ²⁺ , Fe ³⁺ , Co ²⁺ , Co ³⁺ , Ni ²⁺ , Mn ²⁺ , Sn ²⁺ , Sn ⁴⁺ , Pb ²⁺ , Al ³⁺ , Sr ²⁺ , Cr ³⁺ , Cd ²⁺ , Cu ²⁺ , La ³⁺ , Ce ³⁺ , Ce ⁴⁺ , Eu ³⁺ , Mg ²⁺ , Ti ⁴⁺ , Ag ⁺ , Rh ^{2 +} , Ru ²⁺ , Ru ³⁺ , Pd ²⁺

M ^{2 is} a metal ion selected from the group containing Fe ²⁺ , Fe ³⁺ , Co ²⁺ , Co ³⁺ , Mn ²⁺ , Mn ³⁺ , Ni ²⁺ , Cr ²⁺ , Cr ³⁺ , Rh ³⁺ , Ru ²⁺ , Ir ³⁺

and M ¹ and M ^{2 are the} same or different,

X is an anion selected from the group comprising halide, hydroxide, sulfate, hydrogensulfate, carbonate, bicarbonate, cyanide, thiocyanate, isocyanate, cyanate, carboxylate, oxalate, nitrate or nitrite (NO 2 O) or a mixture of two or more of the above anions or a mixture of one or more of the abovementioned anions with one of the uncharged species selected from CO, H ₂ O and NO,

Y is an anion other than X selected from the group comprising, halide, sulfate, hydrogensulfate, disulfate, sulfite, sulfonate (= RSO ₃ - with R = C ₁ -C 20 -alkyl, aryl, C ₁ -C 20 -alkylaryl), carbonate, Bicarbonate, cyanide, thiocyanate, isocyanate, isothiocyanate, cyanate, carboxylate, oxalate, nitrate, nitrite, phosphate, hydrogen phosphate, dihydrogen phosphate, diphosphate, borate, tetraborate, perchlorate, tetrafluoroborate, hexafluorophosphate, tetraphenylborate,

L is a water-miscible ligand selected from the group comprising alcohols, aldehydes, ketones, ethers, polyethers, esters, polyesters, polycarbonate, ureas, amides, nitriles, and sulfides or mixtures thereof,

P is an organic additive selected from the group comprising polyethers, polyesters, polycarbonates, polyalkylene glycol sorbitan esters, polyalkylene glycol glycidyl ethers, polyacrylamide, poly (acrylamide-co-acrylic acid), polyacrylic acid, poly (acrylamide-co-maleic acid), polyacrylonitrile, polyalkyl acrylates, polyalkyl methacrylates , Polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl acetate, polyvinyl alcohol, poly-N-vinylpyrrolidone, poly (N-vinylpyrrolidone-co-acrylic acid), polyvinyl methyl ketone, poly (4-vinylphenol), poly (acrylic acid-co-styrene), oxazoline polymers, Polyalkyleneimines, maleic acid and maleic anhydride copolymer, hydroxyethylcellulose, polyacetates, ionic surfactants and surface-active compounds, bile acid or its salts, esters or amides, carboxylic esters of polyhydric alcohols and glycosides. such as

a, b, d, g, n, r, s, j, k and t are whole or fractional numbers greater than zero, e, f, h and z are integers or fractions greater than or equal to zero,

in which

a, b, d, g, n, j, k and r and s and t are selected to ensure electroneutrality,

M ^{3 is} hydrogen or an alkali or alkaline earth metal, as well as

M ⁴ alkali metal ions or an ammonium ion (NH ₄ ⁺ ) or alkylammonium ion (R ₄ N ⁺ , R ₃ NH ⁺ , R ₂ NH ₂ ⁺ , RNH ₃ ⁺ with R = C ₁ -C 20 -alkyl).

In a particularly preferred embodiment of the invention, M ^{1 is} Zn ²⁺ and M ^{2 is} Co ³⁺ or Co ²⁺ .

The metals M ¹ and M ² are especially the same if they are cobalt, manganese or iron.

The residues of the catalyst can remain in the product obtained, or be neutralized with an acid, preferably hydrochloric acid, sulfuric acid or acetic acid, the salts can then be removed preferably by, for example, a laundry or by ion exchanger. Optionally, a partial neutralization can take place and the product can be used further without further separation of the salts.

It is a preferred embodiment of the present invention, the component (B), regardless of their preparation to rid of essential metal traces. Preferred is a content of metals (in total) below 500 mg / kg, more preferably below 300 mg / kg and most preferably below 100 mg / kg.

Moreover, or instead, it may be useful to at least partially neutralize bases contained in component (B), preferably with acetic acid or para-toluenesulfonic acid, so that the basicity (determined by potentiometric titration with 0.1 molar hydrochloric acid) is less than 20 mmol / kg, preferably less than 15, more preferably less than 10 and most preferably less than 5 mmol / kg.

By at least one of these measures, preferably by reducing the metal content, it is possible to increase the color number of the resulting water-dispersible polyisocyanates. nate compared to polyalkylene oxides (B), which do not have these features.

Preferably, components (A) and (B) are completely, i. at least 90%, based on hydroxyl groups in component (B), preferably at least 95% and particularly preferably at least 98%, reacted with one another to form the water-dispersible polyisocyanate according to the invention.

However, it is also conceivable, although less preferred, to use components (A) and (B) as an unreacted mixture.

For reacting the components (A) and (B), the isocyanurate of 1,6-hexamethylene diisocyanate (A) and the monofunctional polyethylene oxide (B) are mixed in a ratio which corresponds to the desired proportion of the polyethylene oxide (B) in the final water-dispersible polyisocyanate according to the invention equivalent.

The reaction can be carried out by simple heating, preferably with thorough mixing in the absence of a catalyst.

The temperature is in this reaction usually up to 150 ⁰ C, preferably up to 120 ⁰ C, more preferably below 110 ⁰ C and most preferably below 100 ⁰ C.

In general, the temperature of the reaction should be at least 40 ^° C., preferably at least 50, particularly preferably at least 60, and very particularly preferably at least 70 ^° C.

However, it can also be useful for the reaction to carry out the reaction in the presence of a catalyst capable of accelerating urethanization.

Catalysts are in this case those compounds which, owing to their presence in a starting material mixture, lead to a higher proportion of urethane group-containing reaction products than the same starting material mixture in their absence under the same reaction conditions.

These are, for example, organic amines, in particular tertiary aliphatic, cycloaliphatic or aromatic amines, and / or Lewis acidic organic metal compounds. As Lewis acidic organic metal compounds, for example tin compounds in question, such as tin (II) salts of organic carboxylic acids, such as tin (II) diacetate, tin (II) dioctoate, tin (II) - bis (ethylhexanoate) and tin (II) dilaurate and the dialkyltin (IV) salts of organic carboxylic acids, for example dimethyltin diacetate, dibutyltin diacetate, dibutyltin dibutyrate, dibutyltin bis (2-ethylhexanoate), dibutyltin dilaurate, dibutyltin maleate, dioctyltin dilaurate and dioctyltin diacetate. In addition, zinc (II) salts can be used, such as zinc (II) dioctoate. Metal complexes such as acetylacetonates of iron, titanium, aluminum, zirconium, manganese, nickel, zinc 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, dioctyltin dilaurate, zinc (II) dioctoate, 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. As bismuth and cesium salts include those compounds come into consideration, in which the following anions are used: F, Ch, CIO, ^"CIO3-, CIO ₄ -, Br, J, JO ₃ -, CN, OCN, NO ₂ ^" , NO ₃ ^" , HCO ₃ -, CO ₃ ^{2 "} , S ^2" , SH ^" , HSO ₃ -, SO ₃ ^2" , HSO ₄ ^" , SO ₄ ^2" , S ₂ O ₂ ² -, S ₂ O ₄ ^{2 "} , S ₂ O ₅ ² -, S ₂ O ₆ ² -, S ₂ O ₇ ^2" , S ₂ O ₈ ^{2 "} , H ₂ PO ₂ -, H ₂ PO ₄ ^" , HPO ₄ ^{2 "} , PO ₄ ^{3 "} , P ₂ O ₇ ^4" , (OC _n H _{2n +} I) -, (C _n H _2n -IO ₂ ) -, (C _n H _2n -SO ₂ ) -, and (C _{n +} iH _2n - ₂ O ₄ ) ² -, where n is the numbers 1 to 20.

Preference is given to bismuth and cesium carboxylates in which the anion conforms to the formulas (C _n H _2n -iO ₂ ) - as well as (C _n + iH _2n - ₂ O ₄ ) ² - where n is 1 to 20. Particularly preferred cesium salts have as anions monocarboxylates of the general formula (C _n H _2n -i0 ₂ ) -, where n is the numbers 1 to 20. Particular mention should be made here of formate, acetate, propionate, hexanoate, 2-ethylhexanoate and neodecanoate.

Furthermore, can be used as catalysts:

- Organic metal salts of the formula (A) _n -RO-CO-O ^θ M ^® according to US-A-3,817,939, in which:

A is a hydroxyl group or a hydrogen atom, n is a number from 1 to 3,

R is a polyfunctional linear or branched, aliphatic or aromatic hydrocarbon radical and

M ^ffl in cation, for example an alkali metal cation or a quaternary ammonium cation, such as

Tetraalkylammonium, as well

- Quaternary hydroxyalkylammonium compounds of the formula

R ²⁴ , R ²⁵ , R ²⁶ N 1 -CH ₂ -CH (OH) -R ^{27 Θ} _O - (CO) -R ²⁸ as catalyst according to DE-A-26 31 733 (US Pat. No. 4,040,992) with the definitions of the radicals given there.

Particularly suitable as catalysts for the process are quaternary ammonium salts corresponding to the formula

R ¹⁰ -

With

Y ^θ = carboxylate (R ¹³ COO-), fluoride (P), carbonate (R ¹³ O (CO) O ^" ) or hydroxide (OH-),

as described for Y = OH in US Patent 4,324,879 and in German Offenlegungsschriften 2,806,731 and 2,901,479.

Preferably, the radical Y ^θ is a carboxylate, carbonate or hydroxide and more preferably a carboxylate or hydroxide.

R ¹³ is hydrogen, C 1 to C 20 alkyl, C 6 to C 12 aryl or C 7 to C 20 arylalkyl, each of which may optionally be substituted.

Preferably, R ^{13 is} hydrogen or Ci to Cio-alkyl.

Preferred quaternary ammonium salts are those in which the radicals R ⁹ to R ^{12 represent} identical or different alkyl groups having 1 to 20, preferably 1 to 4, carbon atoms, which are optionally substituted by hydroxyl or phenyl groups.

Two of the radicals R ⁹ to R ¹² can also form a heterocyclic, five-, six- or seven-membered ring together with the nitrogen atom and optionally a further nitrogen or oxygen atom. The radicals R ⁹ to R ¹¹ may in any case also represent ethylene radicals which together with the quaternary nitrogen atom and another tertiary nitrogen atom form a bicyclic triethylenediamine structure, provided that the radical R ¹² then represents a hydroxyalkyl group having 2 to 4 carbon atoms, in which the hydroxyl group is preferably located at the 2-position to the quaternary nitrogen atom. The hydroxy-substituted radical or the hydroxy-substituted radicals may also contain other substituents, for example C 1 -C 4 -alkyl-hydroxy substituents. The ammonium ions may also be part of a mono- or poly-ring system, for example derived from piperazine, morpholine, piperidine, pyrrolidine, quinuclidine or di-aza-bicyclo [2.2.2] octane.

Examples of groups having from 1 to 20 carbon atoms R ⁹ to R ¹² are each independently methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl , 2,4,4-trimethylpentyl, nonyl, isononyl, decyl, dodecyl, tetradecyl, heptadecyl, octadecyl, 1, 1-dimethylpropyl, 1, 1-dimethylbutyl, 1,1,3,3-tetramethylbutyl, benzyl, 1 -Phenylethyl, 2-phenylethyl, α, α-dimethylbenzyl, benzhydryl, p-tolylmethyl, 1- (p-butylphenyl) -ethyl, p-chlorobenzyl, 2,4-dichlorobenzyl, p-methoxybenzyl, m-ethoxybenzyl, 2-cyanoethyl , 2-cyanopropyl, 2-methoxycarbonethyl, 2-ethoxycarbonylethyl, 2-butoxycarbonylpropyl, 1, 2-di- (methoxycarbonyl) -ethyl, 2-methoxyethyl, 2-ethoxyethyl, 2-butoxyethyl, diethoxymethyl, diethoxyethyl, chloromethyl, 2-chloroethyl , Trichloromethyl, trifluoromethyl, 1, 1-dimethyl-2-chloroethyl, 2-methoxyisopropyl, 2-ethoxyethyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 4-hydroxybutyl, 6-hydroxyhexyl, 2-hydroxy-2,2 -dimethylethyl, 2-P 4-phenoxybutyl, 6-phenoxyhexyl, 2-methoxyethyl, 2-methoxypropyl, 3-methoxypropyl, 4-methoxybutyl, 6-methoxyhexyl, 2-ethoxyethyl, 2-ethoxypropyl, 3-ethoxypropyl, 4-ethoxybutyl, 6-ethoxyhexyl, phenyl, toIyI, xylyl, α-naphthyl, β-naphthyl, 4-diphenylyl, chlorophenyl, dichlorophenyl, trichlorophenyl, difluorophenyl, methylphenyl, dimethylphenyl, trimethylphenyl, ethylphenyl, diethylphenyl, isopropylphenyl, tert-butylphenyl, dodecylphenyl, methoxyphenyl, dimethoxyphenyl, methylnaphthyl, isopropylnaphthyl, chloronaphthyl, 2,6-dimethylphenyl, 2,4,6-trimethylphenyl, 2,6-dimethoxyphenyl, 2,6-dichlorophenyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl , Methylcyclopentyl, dimethylcyclopentyl, methylcyclohexyl, dimethylcyclohexyl, diethylcyclohexyl, butylcyclohexyl, chlorocyclohexyl, dichlorocyclohexyl, dichlorocyclopentyl, norbornyl or norbornenyl.

Preferred are independently of one another the radicals R ⁹ to R ¹² Ci to C ₄ -AlkVl. R ¹² can additionally be benzyl, or a radical of the Fomel

wherein R ¹⁴ and R ^{15 can be} independently hydrogen or Ci to C ₄ -AlkVl.

Particularly preferred radicals R ⁹ to R ¹² are independently methyl, ethyl and n-butyl and for R ¹² additionally benzyl, 2-hydroxyethyl and 2-hydroxypropyl.

The following catalysts may preferably be used for the process according to the invention: Quaternary ammonium hydroxides, preferably N, N, N-trimethyl-N-benzylammonium hydroxide and N, N, N-trimethyl-N- (2-hydroxypropyl) -ammonium hydroxide, according to DE-A-38 06 276.

Hydroxyalkyl-substituted quaternary ammonium hydroxides according to EP-A-10 589 (US Pat. No. 4,324,879).

Organic metal salts of the formula (A) _n -RO-CO-O ^ M * according to US Pat. No. 3,817,939, in which A, a hydroxyl group or a hydrogen atom, n is a number from 1 to 3, R is a polyfunctional linear or branched, aliphatic or aromatic hydrocarbon radical and M is a cation of a strong base, for example an alkali metal cation or a quaternary ammonium cation, such as tetraalkylammonium.

Preferred catalysts are zinc (II) salts, among these especially zinc acetylacetate.

Also preferred is dibutyltin dilaurate.

Depending on the activity, the catalyst is normally used in amounts of 0.0005 to 10 mol% with respect to isocyanate groups used, preferably 0.001 to 8, more preferably 1 to 7 and very particularly preferably 2 to 5 mol%.

It may also be useful to carry out the urethanization of the polyethylene oxide (B) simultaneously with the trimerization of 1, 6-hexamethylene diisocyanate, as described in WO 2008/116764, there especially from page 19, line 32 to page 22, line 36th

In a preferred embodiment, the reaction of components (A) and (B) is carried out in such a way that in the water-dispersible polyisocyanate according to the invention the proportion of polyethylene oxide chains bound via allophanate groups is less than 20%, based on the entirety of the polyethylene oxide chains, particularly preferably not more is 15%, more preferably not more than 10% and in particular not more than 5%.

It is a preferred embodiment of the present invention to carry out the reaction of components (A) and (B) in such a way that the proportion of polyethylene oxide chains bound to a polyisocyanate via urethane groups is higher than the proportion of allophanate groups bound to a polyisocyanate Polyethylene oxide chains, it is preferably at least 1, 2 times higher, more preferably it is at least 1, 5 times higher, and most preferably at least 2 times higher. This feature leaves more reactive isocyanate groups in the water-dispersible polyisocyanate according to the invention.

Another object of the present invention are mixtures of the inventive water-dispersible polyisocyanates with polyisocyanates (C), which are other than the polyisocyanate (A).

Polyisocyanates (C) are obtainable by reacting at least one monomeric isocyanate.

The monomeric isocyanates used may be aromatic, aliphatic or cycloaliphatic, preferably aliphatic or cycloaliphatic, which is referred to in this document briefly as (cyclo) aliphatic, particularly preferred are aliphatic isocyanates.

Aromatic isocyanates are those which contain at least one aromatic ring system, ie both purely aromatic and also araliphatic compounds.

Cycloaliphatic isocyanates are those containing at least one cycloaliphatic ring system.

Aliphatic isocyanates are those which contain exclusively straight or branched chains, ie acyclic compounds.

The monomeric isocyanates are preferably diisocyanates which carry exactly two isocyanate groups. In principle, however, it may also be monoisocyanates with an isocyanate group.

In principle, higher isocyanates having on average more than 2 isocyanate groups are also considered. For example, triisocyanates such as triisocyanato, 2,4,6-triisocyanatotoluene, triphenylmethane triisocyanate or 2,4,4'-triisocyanato-diphenyl ether or the mixtures of di-, tri- and higher polyisocyanates suitable for example by phosgenation of corresponding aniline / Formaldehyde condensates are obtained and represent methylene bridges Polyphenylpolyiso- cyanate.

These monomeric isocyanates have no significant reaction products of the isocyanate groups with itself.

The monomeric isocyanates are preferably isocyanates having 4 to 20 C atoms. Examples of customary diisocyanates are aliphatic diisocyanates, such as tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, hexamethylene diisocyanate (1,6) Diisocyanatohexane), octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, derivatives of lysine diisocyanate, trimethylhexane diisocyanate or tetramethylhexane diisocyanate, cycloaliphatic diisocyanates such as 1,4,4,1,3 or 1,2-diisocyanatocyclohexane, 4,4'- or 2, 4'-di (isocyanatocyclohexyl) methane, 1-isocyanato-3,3,5-trimethyl-5- (isocyanatomethyl) cyclohexane (isophorone diisocyanate), 1, 3- or 1, 4-bis (isocyanatomethyl) cyclohexane or 2,4- , or 2,6-diisocyanato-1-methylcyclohexane and 3 (or 4), 8 (or 9) -bis (isocyanatomethyl) -tricyclo [5.2.1.0 ²⁶ ] decane isomer mixtures, and also aromatic diisocyanates such as 2,4- or 2,6-tolylene diisocyanate and isomer mixtures thereof, m- or p-xylylene diisocyanate, 2,4'- or 4,4'-diisocyanatodiphenylmethane and isomer 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'-dimethyldi phenyl, 3-methyldiphenylmethane-4,4'-diisocyanate, tetramethylxylylene diisocyanate, 1,4-diisocyanatobenzene or diphenyl ether-4,4'-diisocyanate.

Particularly preferred are 1, 6-hexamethylene diisocyanate, 1, 3-bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate and 4,4'- or 2,4'-di (isocyanatocyclohexyl) methane, most preferably isophorone diisocyanate and 1, 6- Hexamethylene diisocyanate, particularly preferred is 1,6-hexamethylene diisocyanate.

There may also be mixtures of said isocyanates.

Isophorone diisocyanate is usually present as a mixture, namely the cis and trans isomers, usually in the ratio of about 60:40 to 80:20 (w / w), preferably in the ratio of about 70:30 to 75:25 and most preferably in the ratio of about 75:25.

Dicyclohexylmethane-4,4'-diisocyanate may also be present as a mixture of the different cis and trans isomers.

For the present invention, it is possible to use both those diisocyanates which are obtained by phosgenation of the corresponding amines and those which are prepared without the use of phosgene, ie by phosgene-free processes. For example, EP-A-0 126 299 (US Pat. No. 4,596,678), EP-A-126,300 (US Pat. No. 4,596,679) and EP-A-355 443 (US Pat. No. 5,087,739) (cycloaliphatic diisocyanates, for example 1, 6-hexamethylene diisocyanate (HDI), isomeric aliphatic diisocyanates having 6 carbon atoms in the alkylene radical, 4,4'- or 2,4'-di (isocyanatocyclohexyl) methane and 1-isocyanato-3-isocyanato-methyl-3,5,5-trimethyl - cyclohexane (isophorone diisocyanate or IPDI) are prepared by reacting the (cyclo) aliphatic diamines with, for example, urea and alcohols to (eye- lo) aliphatic Biscarbaminsäureestern and their thermal cleavage into the corresponding diisocyanates and alcohols. The synthesis is usually carried out continuously in a cyclic process and optionally in the presence of N-unsubstituted carbamic acid esters, dialkyl carbonates and other by-products recycled from the reaction process. Thus obtained diisocyanates generally have a very low or even non-measurable proportion of chlorinated compounds, which is advantageous, for example, in applications in the electronics industry.

The polyisocyanates (C) to which the monomeric isocyanates can be oligomerized are generally characterized as follows:

The average NCO functionality of such compounds is generally at least 1.8, and may be up to 8, preferably 2 to 5 and more preferably 2.4 to 4.

The content of isocyanate groups after the oligomerization, calculated as NCO = 42 g / mol, is, unless stated otherwise, usually from 5 to 25% by weight.

The polyisocyanates (C) are preferably the following compounds:

1) isocyanurate-containing polyisocyanates of aromatic, aliphatic see and / or cycloaliphatic diisocyanates. Particular preference is given here to the corresponding aliphatic and / or cycloaliphatic isocyanato-isocyanurates and in particular those based on isophorone diisocyanate. The isocyanurates present are in particular trisisocyanatoalkyl or trisisocyanatocycloalkyl 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 2.6 to 8.

2) polyisocyanates containing uretdione groups with 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 polyisocyanates containing uretdione groups are used in this context

Invention in admixture with other polyisocyanates, in particular those mentioned under 1). For this purpose, the diisocyanates can be reacted under reaction conditions under which both uretdione groups and the other polyisocyanates are formed, or first the uretdione groups are formed and these are subsequently converted to the other polyisocyanates or the

Diisocyanates are first reacted to the other polyisocyanates and these then to uretdione-containing products.

3) having biuret polyisocyanates with aromatic, cycloaliphatic or aliphatic bound, preferably cycloaliphatic or aliphatic bonded

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 2.8 to 6.

4) polyisocyanates containing urethane and / or allophanate groups with aromatically, aliphatically or cycloaliphatically bonded, preferably aliphatically or cycloaliphatically bonded isocyanate groups, as described, for example, by reacting excess amounts of diisocyanate, for example hexamethylene diisocyanate or isophorone diisocyanate, with monohydric or polyhydric alcohols ( C). These urethane and / or allophanate-containing polyisocyanates generally have an NCO content of 12 to 24 wt .-% and an average NCO functionality of 2.5 to 4.5. Such polyisocyanates containing urethane and / or allophanate groups can be used uncatalyzed or, preferably, in the presence of catalysts such as, for example, ammonium carboxylates or hydroxides, or allophanatization catalysts, e.g. Zn (II) compounds, each in the presence of mono-, di- or polyhydric, preferably monohydric alcohols produced.

5) oxadiazinetrione-containing polyisocyanates, preferably derived from hexamethylene diisocyanate or isophorone diisocyanate. Such oxadiazinetrione-containing polyisocyanates are of diisocyanate and carbon dioxide accessible.

6) polyisocyanates containing iminooxadiazinedione groups, preferably derived from hexamethylene diisocyanate or isophorone diisocyanate. Such iminooxadiazine-dione-containing polyisocyanates can be prepared from diisocyanates by means of special catalysts.

7) Uretonimine-modified polyisocyanates.

8) carbodiimide-modified polyisocyanates.

9) Hyperbranched polyisocyanates, as are known, for example, from DE-A1 10013186 or DE-A1 10013187.

10) polyurethane-polyisocyanate prepolymers of di- and / or polyisocyanates with alcohols.

1 1) polyurea-polyisocyanate prepolymers.

12) The polyisocyanates 1) -11), preferably 1), 3), 4) and 6) may, after their preparation, comprise polyisocyanates having aryl, cycloaliphatic or aliphatic bound groups in biuret group or urethane / allophanate groups, preferably (cyclo) aliphatically bound isocyanate groups are transferred. The formation of biuret groups takes place, for example, by addition of water or reaction with amines. The formation of urethane and / or allophanate groups by reaction with mono-, di- or polyhydric, preferably monohydric alcohols, optionally in the presence of suitable catalysts. These biuret or urethane / allophanate groups containing polyisocyanates generally have an NCO content of 18 to 22 wt .-% and an average NCO functionality of 2.8 to 6 on.

13) Hydrophilic modified polyisocyanates, i. Polyisocyanates which contain, in addition to the groups described under 1-12, those which formally arise by addition of molecules with NCO-reactive groups and hydrophilicizing groups to the isocyanate groups of the above molecules. The latter are nonionic groups such as alkyl polyethylene oxide and / or ionic, which are derived from phosphoric acid, phosphonic acid, sulfuric acid or sulfonic acid, or their salts.

14) Modified polyisocyanates for dual-cure applications, ie polyisocyanates containing in addition to the groups described under 1-12 those formally by the addition of molecules with NCO-reactive groups and by UV or actinic radiation crosslinkable groups are formed on the isocyanate groups of the above molecules. These molecules are, for example, hydroxyalkyl (meth) acrylates and other hydroxy-vinyl compounds.

The diisocyanates or polyisocyanates (C) listed above may also be present at least partially or preferably completely in blocked form.

Classes of compounds used for blocking are described in D.A. Wicks, Z. W. Wicks, Progress in Organic Coatings, 36, 148-172 (1999), 41, 1-83 (2001) and 43, 131-140 (2001).

Examples of classes of compounds used for blocking are phenols, imidazoles, triazoles, pyrazoles, oximes, N-hydroxyimides, hydroxybenzoic acid esters, secondary amines, lactams, CH-acidic cyclic ketones, malonic esters or alkyl acetoacetates.

In a preferred embodiment of the present invention, the polyisocyanate (C) is selected from the group consisting of isocyanurates, biurets, urethanes and allophanates, preferably from the group consisting of isocyanurates, urethanes and allophanates, more preferably from the group consisting of isocyanurates and Allophanates, in particular is an isocyanurate group-containing polyisocyanate.

In a particularly preferred embodiment, the polyisocyanate (C) is isocyanurate-containing polyisocyanates of 1,6-hexamethylene diisocyanate.

In a further particularly preferred embodiment, the polyisocyanate (C) is an isocyanurate-containing polyisocyanate of isophorone diisocyanate or a uretdione-containing polyisocyanate of 1,6-hexamethylene diisocyanate.

When the water-dispersible polyisocyanate according to the invention is used in admixture with other polyisocyanates (C), care must be taken that the amount of reaction product of polyisocyanate (A) and polyethylene oxide (B) is chosen such that it is sufficient to use the total amount of polyisocyanates ( A) and (C) to disperse.

A further subject matter of the present invention is polyurethane coating compositions comprising - at least one water-dispersible polyisocyanate according to the invention,

optionally at least polyisocyanate (C),

- At least one hydroxyl-containing binder (D). The hydroxy-containing binders (D) are preferably aqueous solutions, emulsions or dispersions of polyols: polyacrylate, polyester, polyurethane, polyetherol, Polycarbonatol dispersions, and their hybrids and / or mixtures of mentioned polyols. Hybrid means graft copolymers and other chemical reaction products containing chemically bound moieties with different (or even the same) of said moieties.

Polyacrylatols can be prepared as primary or secondary dispersions, emulsions, solutions. These are made from olefinically unsaturated monomers. These are first acid group containing comonomers with e.g. Carboxyl, sulfonic acid and / or phosphonic acid groups or their salts, e.g. (Meth) acrylic acid, vinylsulfonic acid or vinylphosphonic acid. These are, secondly, hydroxyl group-containing comonomers, such as hydroxyalkyl esters or amides of (meth) acrylic acid, e.g. 2-hydroxyethyl and 2- or 3-hydroxypropyl (meth) acrylate. Third, these are unsaturated comonomers that have neither acidic nor hydroxyl groups, such as alkyl esters of (meth) acrylic acid, styrene and derivatives, (meth) acrylonitrile, vinyl esters, vinyl halides, vinylimidazole, and others. The properties may e.g. about the composition of the polymer, or e.g. be influenced via the glass transition temperatures of the comonomers (with different hardness).

Polyacrylatoles for aqueous applications are described for example in EP 358979 (US 5075370), EP 557844 (US 6376602), EP 1141066 (US 6528573). An example of a commercially available polyacrylate secondary emulsion is Bayhydrol® A 145 (a product of Bayer MaterialScience). Examples of a polyacrylate

Primary emulsions are Bayhydrol® VP LS 2318 (a product from Bayer MaterialScience) and Luhydran® grades from BASF AG.

Other examples include Macrynal® VSM 6299w / 42WA from Cytec, and Setalux® AQ grades from Nuplex Resins such as Setalux® 6510 AQ-42, Setalux® 651 1 AQ-47, Setalux® 6520 AQ-45, Setalux® 6801 AQ -24, Setalux® 6802 AQ-24, and Joncryl® from BASF Resins.

Polyesterols for aqueous applications are described, for example, in EP 537568 (US Pat. No. 5,344,873), EP 610450 (US Pat. No. 6,319,981) and EP 751,197 (US Pat. No. 5,741,849). Polyester esters for aqueous applications are, for example, WorleePol grades from Worlee- Chemie GmbH, Necowel® grades from Ashland-Südchemie-Kernfest GmbH, and Setalux® 6306 SS-60 from Nuplex Resins.

Polyurethane-polyol dispersions for aqueous applications are described, for example, under EP 469389 (US 559805). They are marketed, for example, under the brand name Daotan® of DSM NV. Polyetherols for aqueous applications are described for example under EP 496210 (US 5304400).

Hybrids and mixtures of the various polyols are described, for example, in EP 424705 (US Pat. No. 4,197,998), EP 496205 (US Pat. No. 5,389,642), EP 542085 (5308912), EP 542105 (US Pat. No. 5,331,039), EP 543228 (US Pat. No. 5,336,711), EP 578940 (US Pat. US 5349041), EP 758007 (US 5750613), EP 751197 (US 5741849), EP 1 141065 (US 6590028).

Polyester / polyacrylates are described, for example, under EP 678536 (US Pat. No. 5,654,391). An example of a polyester / polyacrylate secondary emulsion is Bayhydrol® VP LS 2139/2 (a product of Bayer MaterialScience).

Polyols for aqueous applications are otherwise known under the following brand names: Macrynal®, Viacryl® from Cytec; Bayhydrol® from Bayer MaterialScience (polyacrylate, polyurethane, polyester / polyacrylate, polyester / polyurethane, fatty acid-modified polyester / polyacrylate, polycarbonate dispersions), Alberdingk® and Alberdur® from Alberdingk Boley , Plusaqua® (alkyd, polyester, silicone-polyester) from Omya, Necowel® from Ashland-Südchemie-Kernfest GmbH (alkyd resins), Daotan® from DSM NV (formerly Solutia) (polyester, polycarbonate, fatty acid). based, polyester-urethane-acrylic hybrids), Neocryl® (eg AF-10: acrylic-fluoro-copolymer) from DSM NeoResins.

For incorporation of the water-emulsifiable polyisocyanates according to the invention, it is generally sufficient to distribute the polyisocyanate obtained according to the invention in the aqueous dispersion of the polyol. To generate the emulsion, an energy input of 0 to not more than 10 ⁸ W / m ³ is usually required.

The dispersions generally have a solids content of 10 to 85, preferably from 20 to 70 wt .-% and a viscosity of 10 to 500 m Pas (measured at a temperature of 20 ⁰ C and a shear rate of 250 S " ¹ .

In the dispersion thus prepared, the average particle size (z average), measured by means of dynamic light scattering with the Malvern® Autosizer 2 C, is generally <1000 nm, preferably <500 nm and particularly preferably <200 nm. In the normal case, the diameter is 20 up to 80 nm.

The polyisocyanates obtained according to the invention can be used for the production of polyurethanes and one-component or two-component polyurethane coatings and paints prepared therewith for coating various substrates, such. As wood, wood veneer, paper, cardboard, cardboard, foil, textile, leather, nonwoven, plastic surfaces, glass, ceramics, mineral building materials and metals, which may optionally be pre-coated or pretreated. When used in coating compositions, the polyisocyanates according to the invention can be used in particular in primers, fillers, pigmented topcoats, basecoats and clearcoats in the field of car repair or large vehicle painting. Particularly suitable are those coating compositions for applications in which a particularly high application safety, outdoor weather resistance, optics, solvent, chemical and water resistance are required, such as in the car repair and large vehicle painting.

Such coating compositions are suitable as or in inner or outer coatings, ie those applications that are exposed to daylight, preferably of building parts, decorative finishes, coatings on (large) vehicles and aircraft and industrial applications, bridges, buildings, electricity pylons, tanks , Containers, pipelines, power plants, chemical plants, ships, cranes, piles, sheet piling, fittings, pipes, fittings, flanges, couplings, halls, roofs, structural steel, furniture, windows, doors and parquet, can-coating and coil-coating Such coating compositions are also suitable for floor coverings, such as in parking decks or in hospitals. In particular, the coating compositions according to the invention are used as or in automotive clearcoat, basecoat and topcoat paints, primers and fillers, in particular in the refinish range.

In a preferred form such coating compositions are used at temperatures between ambient temperature to 80 ⁰ C, preferably ⁰ to 60 C, particularly preferably ⁰ to 40 C. Preferably, these are those items that can not be cured at high temperatures, such as large machinery, aircraft, large capacity vehicles, wood, and refinish applications.

Optionally, the isocyanate groups may also be blocked in the polyisocyanates according to the invention. Such blocking groups are described in D.A. Wicks, Z.W. Wicks, Progress in Organic Coatings, 36, 148-172 (1999), 41, 1-83 (2001) and 43, 131-140 (2001).

Preferred blocking groups are phenols, imidazoles, triazoles, pyrazoles, oximes, N-hydroxyimides, hydroxybenzoic acid esters, secondary amines, lactams, CH-acidic cyclic ketones, malonic esters or alkyl acetoacetates.

These groups mentioned can be reacted with the polyisocyanates according to the invention as desired.

Imidazolic groups as groups which are reactive towards isocyanate groups, referred to here for short as "imidazoles", are known, for example, from WO 97/12924 and EP 1591 17, triazoles from US 4482721, CH-acidic cyclic ketones are, for example described in DE-A1 102 60 269, there especially in paragraph [0008] and preferably in paragraphs [0033] to [0037], particularly preferably cyclopentanone-2-carboxylic acid ester and in particular cyclopentanone-2-carboxylic acid ethyl ester.

Preferred imidazoles are, for example, those imidazoles which, in addition to the free NH group, also contain a further functional group, such as e.g. -OH, -SH, -NH-R, -NH2, -CHO, such as, for example, 4- (hydroxymethyl) imidazole, 2-mercapto-imidazole, 2-aminoimidazole, 1- (3-aminopropyl) imidazole, 4, 5-diphenyl-2-imidazolethiol, histamine, 2-imidazole-carboxaldehyde, 4-imidazole carboxylic acid, 4,5-imidazole-dicarboxylic acid, L-histidine, L-carnosine, and 2,2'-bis- (4,5-dimethyl imidazole).

Suitable triazoles are 3-amino-1, 2,4-triazole, 4-amino-1, 2,4-triazole, 3,5-diamino-1, 2,4-triazole, 1H-1, 2,4-triazole-3-thiol , 5-methyl-1 H-1, 2,4-triazole-3-thiol and 3-amino-5-mercapto-1, 2,4-triazole.

Preference is given to phenols, oximes, N-hydroxyimides, lactams, imidazoles, triazoles, malonic esters and alkylacetonates; particularly preferred are lactams, phenols, imidazoles, triazoles and malonic esters, and very particular preference is given to phenols.

It is an advantage of the polyisocyanates according to the invention that they have a lower viscosity, an improved dispersibility and / or an increased content of NCO groups compared to other water-emulsifiable polyisocyanates of similar composition but different preparation.

Examples

Temperature dependence of the viscosity

The viscosity of an isocyanurate polyisocyanate based on 1, 6-hexamethylene diisocyanate (Basonat® HH OO, BASF SE, Ludwigshafen, Germany) with a functionality of 3.7 was determined at 23 ⁰ C to 3250 mPas and at 20 ⁰ C to 4250 mPas.

Polyalkylene oxide 1:

Monofunctional polyethylene oxide prepared on methanol and prepared by potassium hydroxide catalysis, having an OH number of 160 mg KOH / g, measured to DIN 53 240, corresponding to a molecular weight of 350 g / mol. The remaining catalyst residues were then neutralized with acetic acid and the product was desalted. In this case, formed potassium acetate is removed. Polyalkylene oxide 2:

Monofunctional polyethylene oxide prepared on methanol and prepared by potassium hydroxide catalysis, having an OH number of 12 mg KOH / g, measured to DIN 53 240, corresponding to a molecular weight of 500 g / mol. The remaining catalyst residues were then neutralized with acetic acid and the product was desalted. In this case, formed potassium acetate is removed.

Polyalkylene oxide 3:

Monofunctional polyethylene oxide prepared on methanol and prepared by potassium hydroxide catalysis, having an OH number of 75 mg KOH / g, measured to DIN 53 240, corresponding to a molecular weight of 750 g / mol. The remaining catalyst residues were then neutralized with acetic acid and the product was desalted. In this case, formed potassium acetate is removed.

Polyalkylene oxide 4:

Monofunctional polyethylene oxide prepared on methanol and prepared by potassium hydroxide catalysis, having an OH number of 56 mg KOH / g, measured to DIN 53 240, corresponding to a molecular weight of 1000 g / mol. The remaining catalyst residues were then neutralized with acetic acid and the product was desalted. In this case, formed potassium acetate is removed.

example 1

At 60 ⁰ C are employed 100 g Basonat® HI 100 (BASF commercial product, isocyanurate based on 1, 6-hexamethylene diisocyanate with an NCO content of 22.3%, viscosity 4250 mPas (20 ⁰ C)) 14.9 g of Polyalkylene oxide 2 in the presence of 5 ppm of bismuth 2-ethylhexanoate to. After 30 minutes, a finely divided water-dispersible resin having an NCO content of 18.1%, a viscosity (23 ° C.) of 2380 mPas and a color number of 15 Hazen is obtained.

Example 2

At 60 ⁰ C are employed 100 g Basonat® HI 100 (BASF commercial product, isocyanurate based on 1, 6-hexamethylene diisocyanate with an NCO content of 22.3%, viscosity 4250 mPas (20 ⁰ C)) 14.9 g of Polyalkylene oxide 2 in the presence of 40 ppm of bismuth 2-ethylhexanoate to. After 15 minutes, a very readily water-dispersible resin having an NCO content of 17.98%, a viscosity (23 ° C.) of 2507 mPas and a color number of 19 Hazen.

EXAMPLE 3 At 80 ° C are employed 100 g Basonat® HI 100 (BASF commercial product, isocyanurate based on 1, 6-hexamethylene diisocyanate with an NCO content of 22.3%, viscosity 4250 mPas (20 ⁰ C)) 14.9 g of polyalkylene oxide 2 for six hours. This gives a fine Partly water-dispersible resin with NCO content 18.24%, a viscosity (23 ° C) of 2387 mPas and a color number of 16 Hazen.

Comparative Example 1

At 60 ⁰ C are employed 100 g Basonat® HI 100 (BASF commercial product, isocyanurate based on 1, 6-hexamethylene diisocyanate with an NCO content of 22.3%, viscosity 4250 mPas (20 ⁰ C)) with 7.5 g of Polyalkylene oxide 2 in the presence of 40 ppm of bismuth 2-ethylhexanoate to. After 15 minutes, a water-dispersible resin having an NCO content of 19.70%, a viscosity (23 ° C.) of 2674 mPas and a color number of 20 Hazen is obtained.

Comparative Example 2

At 60 ⁰ C is set 100 g of Basonat® HI 100 (commercial product of BASF, isocyanurate based on 1, 6-hexamethylene diisocyanate with NCO content of 22.3%, viscosity 4250 mPas (20 ⁰ C)) with 23.5 g of Polyalkylene oxide 2 in the presence of 40 ppm of bismuth 2-ethylhexanoate to. After 15 minutes, a very finely divided water-dispersible resin having an NCO content of 16.21%, a viscosity (23 ° C) of 2345 mPas and a color number of 20 Hazen.

Comparative Example 3

At 60 ° C, 100 g Basonat® Hl 100 (commercial product of BASF, isocyanurate based on 1, 6-hexamethylene diisocyanate with NCO content of 22.3%, viscosity 4250 mPas (20 ⁰ C)) with 14.9 g of Polyalkylene oxide 1 in the presence of 40 ppm bismuth-2-ethylhexanoate to. After 15 minutes, a very water-dispersible resin having an NCO content of 17.61%, a viscosity (23 ° C.) of 2800 mPas and a color number of 20 Hazen is obtained.

Comparative Example 4

At 80 ° C, 100 g of Basonat® HI 100 (commercial product of BASF, isocyanurate based on 1, 6-hexamethylene diisocyanate with NCO content of 22.3%, viscosity 4250 mPas (20 ⁰ C)) with 14.9 g of Polyalkylene oxide 1 four hours to. A very readily water-dispersible resin having an NCO content of 17.55%, a viscosity (23 ° C.) of 2992 mPas and a color number of 21 Hazen is obtained.

Comparative Example 5

At 80 ° C, 100 g of Basonat® HI 100 (commercial product of BASF isocyanurate based on 1, 6-hexamethylene diisocyanate with NCO content of 22.3%, viscosity 4250 mPas (20 ⁰ C)) with 20.48 g of polyalkylene oxide 1 in four hours. A very readily water-dispersible resin having an NCO content of 16.81%, a viscosity (23 ° C.) of 3039 mPas and a color number of 20 Hazen is obtained. Comparative Example 6

At 80 ⁰ C are employed 100 g Basonat® HI 100 (BASF commercial product, isocyanurate based on 1, 6-hexamethylene diisocyanate with an NCO content of 22.3%, viscosity 4250 mPas (20 ⁰ C)) 14.9 g of Polyalkylene oxide 3 for four hours. A very readily water-dispersible resin having an NCO content of 18.2%, a viscosity (23 ° C.) of 2442 mPas and a color number of 30 Hazen is obtained.

Comparative Example 7 At 60 ⁰ C are employed 100 g Basonat® HI 100 (BASF commercial product, isocyanurate based on 1, 6-hexamethylene diisocyanate with an NCO content of 22.3%, viscosity 4250 mPas (20 ⁰ C)) 14.9 g of polyalkylene oxide 4 in the presence of 40 ppm of bismuth 2-ethylhexanoate to. After 15 minutes, a readily water-dispersible resin having an NCO content of 17.8% is obtained, which is solidified at room temperature to give a waxy solid.

Comparative Example 8

At 60 ° C, 100 g of an isocyanurate based on 1, 6-hexamethylene diisocyanate with NCO content of 24.4%, viscosity 2465 mPa ^* s at 20 ° C) with 14.9 g of polyalkylene oxide 2 for four hours at 85 set ° C and one hour at 100 ° C. This gives a readily water-dispersible resin having an NCO content of 20.1% of a viscosity of 1890 mPa ^* s at 23 ° C. and a color number of 22 Hazen.

Application Comparative Experiments: Test Method:

Acetone resistance: The coatings were baked for 30 minutes at 60 ⁰ C. To test the acetone resistance rubbed with an acetone-soaked cotton ball over the surface until the paint layer was rubbed down to the substrate. The indication of the acetone resistance is given in number of double strokes required until breakthrough. The higher the number of double strokes, the more chemical-resistant the paint is to acetone. The values can be considered as a measure of the crosslink density of the paint.

The pendulum hardness was determined to König (EN ISO 1522).

Lacquer films were stored for 24 h at 23 ± 2 ° C and 50 ± 10% humidity.

Recipe 1: Polyol component: 576 g Luhydran® S 937 T, about 50% BASF SE

14 g of butylglycol diacetate Merck Schuchardt OHG

37.2 g butylglycol acetate Merck Schuchardt OHG 37 g of distilled water

8.4 g of dimethylethylamine, 1: 1 in water

21, 6 g of distilled water

3.5g BYK® 340 BYK

697.7g total, about 37% in water

The polyol component was allowed to swell for at least 24 hours. Polyol and isocyanate components were mixed homogeneously with a Dispermat®.

Application tests, quantities in g. The polyisocyanates were used 80% in dipropylene glycol dimethyl ether (Proglyde® DMM, Sigma-Aldrich, Germany). The amounts of polyisocyanates in the following table refer to the 80% solution.

The values are given after storage over the specified period (min = minutes, h = hour, d = day) at the indicated temperature (RT: room temperature 23 ° C.).

The polyisocyanate obtained according to Inventive Example 3 gives a clear lacquer (V1), while Comparative Example 1 (V2) and Comparative Example 2 (V3) lead to a slightly cloudy lacquer. The gloss of paint V2 is also significantly lower. The pendulum hardness development at room temperature and pendulum hardness with forced drying is worse in the comparative examples, as well as the crosslinking density (acetone double strokes), which does not develop as quickly in V3 paint as in the paint V1. In another series of tests, polyol and isocyanate components were homogeneously mixed by hand incorporation.

Examples 1 and 3 according to the invention lead to a clear lacquer, while comparative examples 3 and 6 provide a cloudy lacquer, Comparative Example 6 also contains coagulum particles. The gloss of the two comparative examples is also significantly lower. The pendulum hardness development at room temperature and pendulum hardness with forced drying is worse in Comparative Example 3, as well as the crosslinking density (Acetoppeloppelhübe) developed in Comparative Example 6 is not so fast.

In a further series of experiments, the polyisocyanates were homogeneously mixed with the polyol component by incorporation by hand. The formulation was applied hourly after mixing and tested for acetone resistance after storage for one week at room temperature. The resistance is a measure of the pot life of the formulation.

It turns out that the pot life with the isocyanate from example 3 is longer by about one hour than when using the isocyanate from comparative example 8.

Claims

claims

1. A process for the preparation of water-dispersible polyisocyanates, by reacting an isocyanurate polyisocyanate based on 1, 6-hexamethylene diisocyanate (A) having a viscosity at 20 ⁰ C of at least 3500 mPas with at least one monofunctional polyalkylene oxide (B), in the statistical average 10th , 5 to 14 ethylene oxide units in copolymerized form and wherein the proportion of the polyalkylene oxide (B) on water-dispersible polyisocyanate based on the sum of (A) and (B) of 1 1 to 15% by weight.

2. The method according to claim 1, characterized in that it is in component (B) to polyalkylene oxide of the formula

in which

R ^{1 is} a C ¹ -C 4 -alkyl or C ₂ -C 12 -cycloalkyl radical and k is, on average, a number from 10.5 to 14

mean.

3. The method according to claim 2, characterized in that R ¹ is a C ¹ to C ⁴ alkyl radical.

4. The method according to claim 2, characterized in that R ¹ is a methyl radical.

5. The method according to any one of the preceding claims, characterized in that the component (B) to at least 90%, based on hydroxyl groups in component (B), with component (A).

6. The method according to any one of the preceding claims, characterized in that the content of polyisocyanates, the urethane groups (calculated as - (- NH-CO) -O- with a molecular weight of 58 g / mol) or allophanate groups (calculated as -

(N (CONH-XCOO-) with a molecular weight of 101 g / mol), in the end product independently of each other is less than 5% by weight.

7. The method according to any one of the preceding claims, characterized in that the polyalkylene oxide (B) has a basicity (determined by potentiometric

Titration with 0.1 molar hydrochloric acid) of less than 20 mmol / kg.

8. The method according to any one of the preceding claims, characterized in that the polyalkylene oxide (B) has a content of metals (in total) below 500 mg / kg.

9. The method according to any one of the preceding claims, characterized in that in addition to the polyisocyanate (A) at least one polyisocyanate (C) is reacted, which is other than the polyisocyanate (A).

10. The method according to any one of the preceding claims, characterized in that the reaction of the components (A) and (B) leads so that the proportion of urethane on a polyisocyanate bound polyethylene oxide chains (B) is higher than the proportion of about Allophanate groups bound to a polyisocyanate polyethylene oxide chains.

1 1. Polyurethane coating compositions containing

at least one water-dispersible polyisocyanate obtained according to one of the preceding claims 1 to 9,

optionally at least polyisocyanate (C) which is other than the polyisocyanate (A), and - at least one hydroxyl-containing binder (D).

12. polyurethane coating compositions according to claim 1 1, characterized in that the hydroxyl-containing binder (D) is selected from the group consisting of aqueous solutions, emulsions or dispersions of polyacrylate, polyesterol, polyurethane, Polyetherol- and Polycarbonatol-

Dispersions, and their hybrids and / or mixtures.

13. Use of polyurethane coating compositions according to claim 11 or 12 for coating wood, wood veneer, paper, cardboard, cardboard, foil, textile, leather, fleece, plastic surfaces, glass, ceramics, mineral building materials and

Metals, each of which may optionally be precoated or pretreated.

14. Use of water-dispersible polyisocyanates obtained according to any one of claims 1 to 9 in one-component or two-component polyurethane polyurethanes.

15. Use of water-dispersible polyisocyanates obtained according to one of claims 1 to 9 in primers, fillers, pigmented topcoats, basecoats and clearcoats in the field of car repair or Großfahrzeuglackie- tion.