EP1999172A1

EP1999172A1 - Aqueous dispersions based on nitrocellulose-polyurethane particles

Info

Publication number: EP1999172A1
Application number: EP07723038A
Authority: EP
Inventors: Rainer Trinks; Thorsten Rische; Thomas Feller; Steffen Hofacker; Harald Blum; Hans-Ulrich Meier-Westhues
Original assignee: Bayer MaterialScience AG
Current assignee: Bayer Intellectual Property GmbH
Priority date: 2006-03-17
Filing date: 2007-03-05
Publication date: 2008-12-10
Also published as: CN101405314A; TW200745261A; JP2009530454A; US20070219296A1; CA2645726A1; WO2007107232A1; DE102006012354A1

Abstract

The invention relates to aqueous dispersions comprising nitrocellulose-polyurethanepolyurea particles, to a process for their preparation and to their use.

Description

Aqueous dispersions based on nitro-cellulose-polyurethane particles

The invention relates to aqueous dispersions comprising nitrocellulose-polyurethane-polyurea particles, a process for their preparation and their use.

Nitrocellulose or cellulose nitrate or cellulose nitric acid ester is used in a wide variety of applications due to its versatile, conductive and end-use properties

Application fields used.

In the prior art, solvent-borne nitrocellulose compositions, e.g. disclosed as furniture coatings, printing inks or overprint varnishes. These paints are exclusively organic solvent-containing systems.

Also, nail varnishes often have substantially a nitrocellulose base in the binder. Again, predominantly organic solvents such as e.g. Ethyl acetate or butyl acetate.

In many cases, however, there is a desire, on the basis of legal requirements and due to occupational health and environmental protection aspects, to replace solvent-containing systems with aqueous systems while at the same time fully or largely maintaining the desired positive application properties.

Various attempts have therefore been described in the prior art to provide nitrocellulose-containing coating systems based on an aqueous carrier medium and to dispense with organic solvents and coalescing aids proportionally or completely.

In US-A 5,670,141, for example, first nitrocellulose-containing aqueous

Emulsions produced, to which complex emulsification steps are necessary. In addition, they also have solvents or plasticizers. Subsequently, the emulsions are then combined with other polymers to form an aqueous system. In this way, mixtures of independently produced nitrocellulose arise on the one hand, with polymer dispersions on the other hand.

Another method is described e.g. in WO-A 92/01817, wherein nitrocellulose emulsions and other aqueous systems are sequentially coated on a substrate, such as e.g. Leather are applied, which always results in several process steps.

Solvent-containing systems based on nitrocellulose and polyurethane are known from the prior art, for example JP-A 03 294 370, JP-A 03 247 624 or JP-A 58-83 001. These described nitrocellulose compositions are used as dispersing media for magnetic powders.

JP-A 63-14735 discloses aqueous resin emulsions based on water-dispersible, urethane-modified vinyl polymers and nitrocellulose. The vinyl polymer has an ionic group and a polyurethane side chain which serves as a dispersing medium for the nitrocellulose. The compositions described there are used as coating agents. The resin emulsion is prepared by dissolving both the vinyl polymer and the nitrocellulose in an organic solvent, then adding water and dispersing the polymer using a neutralizing agent. The organic solvent can be removed before or after the dispersion. A disadvantage of these systems is their lack of storage stability, when the amount of solvent is significantly reduced by distillation.

Due to the pronounced hydrophobicity of the nitrocellulose, a complete replacement of organic solvents and coalescing aids by water, while retaining the same level of properties has not been achieved by the prior art methods. In particular, aqueous dispersions containing nitrocellulose polyurethaneurea particles are not described.

The object of the present invention was therefore to provide stable and sedimentation-free aqueous dispersions based on a polyurethane polymer and nitrocellulose, which have residual organic solvent amounts of less than or equal to 1% by weight with respect to the dispersion and, moreover, do not contain any additional external emulsifiers or external plasticizers capable of migrating , The coating compositions prepared from the dispersions of the invention should be sufficiently film-forming and (mechanically) stable during drying, so that coatings, coatings, sizes, paints, adhesives, binders, printing inks, cosmetics and personal care articles and the like for a variety of substrates formulated so can be.

It has now surprisingly been found that dispersions which have both polyurethane polymer proportions and nitrocellulose fractions and an average particle size of 20 nm to 700 nm, meet the above requirements. It is possible with these polyurethane-nitrocellulose particles to produce stable, aqueous dispersions, without additionally adding plasticizers,

Use emulsifiers or auxiliary solvents.

The invention therefore relates to aqueous dispersions containing polyurethane-nitrocellulose particles having a particle size of from 20 to 700 nm, preferably from 30 to 550 nm, especially preferably from 50 to 400 nm and very particularly preferably from 100 to 330 nm, which comprises a polyurethane fraction which, as constituent components, compounds selected from the group

a) the organic polyisocyanates,

b) the polyols having number-average molecular weights of from 400 to 8000 g / mol, preferably from 400 to 6000 g / mol and more preferably from 600 to 3000 g / mol and having an OH functionality of from 1.5 to 6, preferably 1, 8 to 3, and more preferably from 1.9 to 2.1,

c) the low molecular weight compounds of the molecular weight 62 to 400 g / mol, preferably 62 to 240 g / mol, particularly preferably 88 to 140 g / mol, which have two or more hydroxyl and / or amino groups,

d) the low molecular weight compounds which have a hydroxyl or amino group,

e) the isocyanate-reactive compounds which additionally carry ionic or potentially ionic hydrophilizing groups, and

f) contains the isocyanate-reactive, nonionic hydrophilic compounds and

have a proportion of water-insoluble nitrocellulose.

The water-insoluble nitrocellulose preferably has a nitrogen content of 10.0 to 12.8 wt .-%, more preferably a nitrogen content of 10.7 to 12.6 wt .-%, most preferably a nitrogen content of 10.7 to 12.3 Wt .-% based on dry matter of nitrocellulose, on.

The present invention also provides a process for the preparation of the novel aqueous dispersion comprising polyurethane-nitrocellulose particles, characterized in that the synthesis components containing compounds selected from the group

a) the organic polyisocyanates,

b) the polyols having number-average molecular weights of from 400 to 8000 g / mol, preferably from 400 to 6000 g / mol and more preferably from 600 to 3000 g / mol and having an OH functionality of from 1.5 to 6, preferably 1, 8 to 3, and more preferably from 1.9 to 2.1, c) the low molecular weight compounds of the molecular weight 62 to 400 g / mol, preferably 62 to 240 g / mol, particularly preferably 88 to 140 g / mol, which have two or more hydroxyl and / or amino groups,

d) the low molecular weight compounds which have a hydroxy or amino group,

e) the isocyanate-reactive compounds which additionally carry ionic or potentially ionic hydrophilicizing groups, and

f) the isocyanate-reactive, nonionically hydrophilicizing compounds,

be implemented so that first a urea group-free, isocyanate-functional prepolymer (i), dissolved in a solvent is prepared, (wherein the molar ratio of isocyanate groups to isocyanate-reactive groups 1.05 to 3.5, preferably 1.2 to 3, 0 is particularly preferably 1.3 to 2.5), then the remaining isocyanate groups are amino-chain extended or terminated (ii) and the nitrocellulose dissolved in acetone or 2-

Butanone, after preparation of the prepolymer (i) or after the chain extension (ii) but before the dispersion or after the dispersion (iii) is added before the distillation.

Suitable polyisocyanates of component a) are the aromatic, araliphatic, aliphatic or cycloaliphatic polyisocyanates known to those skilled in the art of an NCO functionality of preferably equal to 2.

Examples of suitable polyisocyanates are 1, 4-butylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 2,2,4- and / or 2,4,4-trimethylhexamethylene diisocyanate, the isomeric bis (4,4 ' -isocyanatocyclohexyl) methanes or mixtures thereof of any isomer content, 1,4-cyclohexylene diisocyanate, 1,4-phenylene diisocyanate, 2,4- and / or 2,6-toluene diisocyanate, 1,5-naphthylene diisocyanate, 2,4'- or 4 , 4'-diphenylmethane diisocyanate, 1,3- and 1,4-bis (2-isocyanato-prop-2-yl) -benzene (TMXDI), 1,3-bis (isocyanato-methyl) -benzene (XDI), ( S) -alkyl-2,6-diisocyanatohexanoate or (L) -alkyl 2,6-diisocyanatohexanoate.

Proportionally, it is also possible to use polyisocyanates having an NCO functionality of greater than 2. These include modified diisocyanates having a uretdione, isocyanurate, urethane, allophanate, biuret, iminooxadiazinedione and / or oxadiazinetrione structure and unmodified polyisocyanate having more than 2 NCO groups per molecule, for example 4-isocyanatomethyl-1,8 octane diisocyanate (nonane triisocyanate) or triphenylmethane-4,4 ', 4 "-triisocyanate. Preference is given to polyisocyanates or polyisocyanate mixtures of the abovementioned type having exclusively aliphatically and / or cycloaliphatically bonded isocyanate groups having an average functionality of from 2 to 4, preferably from 2 to 2.6 and more preferably from 2 to

2.4.

Particularly preferred are hexamethylene diisocyanate, isophorone diisocyanate, the isomeric Bis-

(4,4'-isocyanatocyclohexyl) methanes, and mixtures thereof.

Polymeric polyols which can be used as compounds b) have a molecular weight Mn of from 400 to 8000 g / mol, preferably from 400 to 6000 g / mol and more preferably from 600 to 3000 g / mol. Their hydroxyl number is 22 to 400 mg KOH / g, preferably 30 to 200 mg KOH / g and more preferably 40 to 160 mg KOH / g and have an OH functionality of 1.5 to 6, preferably from 1.8 to 3 and more preferably from 1.9 to 2.1.

For the purposes of the present invention, polyols are the organic polyhydroxyl compounds known in polyurethane coating technology, such as the customary polyester polyols, polyacrylate polyols, polyurethane polyols, polycarbonate polyols, polyether polyols, polyester polyacrylate polyols and polyurethane polyacrylate polyols, polyurethane polyester polyols, polyurethane polyether polyols, polyurethane polycarbonate polyols, polyester polycarbonate polyols, alone or in mixtures.

Preferred polyols are polyester polyols, e.g. the known polycondensates of di- and optionally tri - and tetraols and di- and optionally tri- and tetracarboxylic acids or hydroxycarboxylic acids or lactones. Instead of the free polycarboxylic acids, it is also possible to use the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols for the preparation of the polyesters.

Examples of suitable diols are ethylene glycol, butylene glycol, diethylene glycol, triethylene glycol, polyalkylene glycols such as polyethylene glycol, furthermore 1,2-propanediol, 1,3-propanediol, butanediol (1,3) butanediol (1,4), hexanediol (1 , 6) and isomers, neopentyl glycol, the latter three compounds being preferred. Examples of suitable polyols to be used here are trimethylolpropane, glycerol, erythritol, pentaerythritol or trishydroxyethyl isocyanurate.

Suitable dicarboxylic acids are, for example: phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexanedicarboxylic acid, adipic acid,

Azelaic acid, sebacic acid, glutaric acid, maleic acid, fumaric acid, itaconic acid, malonic acid,

Korksäure, 2-Methylsuccinic acid and their possible anhydrides. For the interests of the present Consequently, the anhydrides are included in the invention by the term "acid". Monocarboxylic acids such as benzoic acid and hexanecarboxylic acid may also be used, provided that the average OH functionality of the polyol is> 2. Saturated aliphatic or aromatic acids are preferred, such as adipic acid or isophthalic acid. As polycarboxylic acid which may optionally be used in smaller amounts, trimellitic acid may be mentioned here.

Hydroxycarboxylic acids which can be used as reactants in the preparation of a polyester polyol having terminal hydroxyl groups are, for example, hydroxycaproic acid or hydroxybutyric acid. Suitable lactones are e.g. Caprolactone, butyrolactone and their homologues.

Particularly preferred polyester polyols are hexanediol adipic acid ester, butanediol adipic acid ester, hexanediol neopentyl glycol adipic acid ester and hexanediol phthalic acid ester.

Also preferred as compounds b) are hydroxyl group-containing polycarbonates having a molecular weight Mn of 400 to 6000 g / mol, preferably of 600 to 3000 g / mol, which are e.g. by reaction of carbonic acid derivatives, such as diphenyl carbonate, dimethyl carbonate or phosgene with polyols, preferably diols are obtainable.

As such diols come e.g. Ethylene glycol, 1,2- and 1,3-propanediol, 1,3- and 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol, 1,4-bis-hydroxymethylcyclohexane, 2-methyl-1, 3-propanediol, 2,2,4-trimethylpentanediol-l, 3, dipropylene glycol, polypropylene glycols, dibutylene glycol, polybutylene glycols, bisphenol A, tetrabromobisphenol A but also lactone-modified diols in question. Preferably, the diol component contains from 40 to 100% by weight of 1,6-hexanediol. Proportionally, hexanediol derivatives can also be used, preferably those which, in addition to terminal OH groups, contain ether or ester groups, e.g. Products which can be obtained by reacting 1 mole of hexanediol with at least 1 mole, preferably 1 to 2 moles of caprolactone or by etherification of hexanediol with itself to di- or trihexylenglycol.

Polyether-polycarbonate diols can also be used. The hydroxyl polycarbonates should be substantially linear. However, they may optionally be easily branched by the incorporation of polyfunctional components, especially low molecular weight polyols.

Polyol components b) furthermore include polyether polyols, for example the polyaddition products of styrene oxides, ethylene oxide, propylene oxide, tetrahydrofuran, butylene oxide, epichlorohydrin, and their mixed addition and grafting products, as well as by condensation of polyhydric alcohols or mixtures thereof and by alkoxylation of polyhydric alcohols, amines and amino alcohols obtained polyether polyols. _?

The low molecular weight polyols c) used to build up the polyurethane resins generally cause stiffening and / or branching of the polymer chain and are preferably used during the prepolymer synthesis. The molecular weight is preferably between 62 and 400 g / mol, more preferably between 62 and 200 g / mol. Suitable polyols c) may contain aliphatic, alicyclic or aromatic groups. Mention may be made, for example, of the low molecular weight polyols having up to about 20 carbon atoms per molecule, such as e.g. Ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, cyclohexanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol, neopentyl glycol, bisphenol A (2,2 Bis (4-hydroxyphenyl) propane), hydrogenated bisphenol A (2,2-bis (4-hydroxycyclohexyl) propane), and trimethylolpropane, glycerol or pentaerythritol and mixtures of these and optionally other low molecular weight polyols c). Preference is given to 1,4-butanediol, 1,6-hexanediol, neopentyl glycol and trimethylolpropane.

For chain extension of the NCO-terminated prepolymer, di- or polyamines and hydrazides can be used as component c), e.g. Ethylenediamine, 1,2- and 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, isophoronediamine, isomer mixture of 2,2,4- and 2,4,4-

Trimethylhexamethylenediamine, 2-methylpentamethylenediamine, diethylenetriamine, and 4,4-diamino-dicyclohexylmethane, dimethylethylenediamine, hydrazine or adipic dihydrazide. Preferred are ethylenediamine, diethylenetriamine, isophoronediamine and hydrazine

As component c) are in principle also compounds into consideration, containing active hydrogen with respect to isocyanate groups of different reactivity, such as compounds which have not only a primary amino group but also secondary amino groups or in addition to an amino group (primary or secondary) OH groups. Examples of these are primary / secondary amines, such as 3-amino-1-methylaminopropane, 3-amino-1-ethylaminopropane, 3-amino-1-cyclohexylaminopropane, 3-amino-1-methylaminobutane, furthermore alkanolamines, such as N-aminoethyl- ethanolamine, ethanolamine, 3-aminopropanol, neopentanolamine and more preferably diethanolamine, N- (2-hydroxyethyl) ethylenediamine, N, N'-bis (2-hydroxyethyl) ethylenediamine. These can be used in the preparation of the dispersion according to the invention as chain extenders and / or as chain terminators.

The dispersions according to the invention may optionally contain building blocks d), which are located respectively at the chain ends and terminate them. These building blocks are derived, on the one hand, from monofunctional compounds reactive with NCO groups, such as monoamines, in particular mono-secondary amines or monoalcohols. Preferred are ethanol, n-butanol, 2-ethylhexanol, propylamine, butylamine, stearylamine or dibutylamine. Suitable ionically or potentially ionically hydrophilicizing compounds e) are compounds which have at least one isocyanate-reactive group and at least one functionality, such as, for example, - ^" Y ⁺ , -SO ₃ Y ⁺ , -PO (O ^" Y ⁺ ) ₂ (Y ⁺ = H ⁺ , NH ₄ ⁺ , metal cation), which, upon interaction with aqueous media, undergo a pH-dependent dissociation equilibrium and in this way may be negatively charged or neutral. Preferred isocyanate-reactive groups are hydroxyl or amino groups.

Suitable anionic or potentially anionic hydrophilic compounds according to the definition of component e) are e.g. Mono- and dihydroxycarboxylic acids, mono- and diaminocarboxylic acids, mono- and dihydroxysulfonic acids, mono- and diaminosulfonic acids and also mono- and dihydroxyphosphonic acids or mono- and diaminophosphonic acids and their salts, such as

Dimethylolpropionic acid, dimethylolbutyric acid, hydroxypivalic acid, N- (2-aminoethyl) -β-alanine, 2- (2-aminoethylamino) -ethanesulfonic acid, ethylenediamine-propyl-sulfonic acid or -butylsulfonic acid, 1,2- or 1, 3-propylenediamine-ß-ethylsulfonic acid, malic acid, citric acid, glycolic acid, lactic acid, glycine, alanine, taurine, lysine, 3,5-diaminobenzoic acid, an addition product of IPDI and acrylic acid (EP-A 0 916 647, Example 1) and its alkali and / or ammonium salts; Polyethersulfonate, the propoxylated adduct of 2-butenediol and NaHSO ₃ , for example described in DE-A 2 446 440 (page 5-9, formula I-III). Furthermore, cyclohexylaminopropanesulfonic acid (CAPS) can be used as, for example, in WO-A 01/88006 as a compound corresponding to the definition of component 5).

Preferred compounds e) are those which have carboxy or carboxylate and / or sulfonate groups. Particularly preferred ionic compounds 5) are those which contain carboxyl and / or sulfonate groups as ionic or potentially ionic groups, such as the salts of N- (2-aminoethyl) -β-alanine, of 2- (2-aminoethylamino) -ethanesulfonic acid or the addition product of IPDI and acrylic acid (EP-A 0 916 647, Example 1) and dimethylolpropionic acid.

Suitable nonionic hydrophilic compounds according to the definition of component f) are e.g. Polyoxyalkylene ethers containing at least one hydroxy or amino group. These polyethers contain from 30% to 100% by weight of building blocks derived from ethylene oxide.

Nonionically hydrophilicizing compounds f) are, for example, also monohydric, on average 5 to 70, preferably 7 to 55 ethylene oxide units per molecule having polyalkylenoxidpolyetheralkohole, as they are accessible in a conventional manner by alkoxylation of suitable starter molecules. The polyalkylene oxide polyether alcohols are either pure polyethylene oxide polyethers or mixed polyalkylene oxide polyethers whose alkylene oxide units consist of at least 30 mol%, preferably at least 40 mol%, of ethylene oxide units. Particularly preferred nonionic compounds are monofunctional mixed polyalkylene oxide polyethers which have at least 40 mol% of ethylene oxide and not more than 60 mol% of propylene oxide units.

Suitable starter molecules are e.g. Diethylene glycol monobutyl ether or n-butanol. Alkylene oxides which are suitable for the alkoxylation reaction are, in particular, ethylene oxide and propylene oxide, which can be used in any desired order or even as a mixture in the alkoxylation reaction.

Preference is given to 5 to 40 wt .-% of component a), 55 to 94 wt .-% b), 0.5 to 20 wt .-% of the sum of compounds c) and d), 0.1 to 5 wt. % Component e), 0 to 20 wt .-% component f) is used, wherein the sum of e) and f) is 0.1 to 25 wt .-% and the sum of all components added to 100 wt .-%.

Particularly preferred are 5 to 35 wt .-% of component a), 60 to 90 wt .-% of component b),

0.5 to 15% by weight of the sum of compounds c) and d), 0.1 to 4% by weight of component e), 0 to 15% by weight of component f), where the sum of e) and f) is 0.1 to 19% by weight and the sum of all components adds to 100% by weight.

Very particularly preferred are 10 to 30% by weight of component a), 65 to 85% by weight of component b), 0.5 to 14% by weight of the sum of compounds c) and d), 0.1 up to 3.5% by weight of component e), 0 to 10% by weight of component f), the sum of e) and f) being 0.1 to 13.5% by weight and the sum of all Components added to 100 wt .-%.

Suitable nitrocellulose is water-insoluble nitrocellulose of all viscosity stages. Preference is given to nitrocelluloses which, for example, have the usual collodium qualities (for the term "collodium" see Römpp's Chemie Lexikon, Thieme Verlag, Stuttgart), ie cellulose nitric acid esters having a nitrogen content of 10 to 12.8% by weight, which are present in the Process solvent or process solvent mixture are soluble.

Particularly preferred are cellulose nitric acid esters having a nitrogen content of 10.7 to 12.6 wt .-%, most preferably from 10.7 to 12.3 wt .-%. Examples of such Cellulosesalpeter- are säureester Walsroder ^® nitrocellulose A types (Wolff Cellulosics GmbH & Co. KG,

Bomlitz DE) with a nitrogen content of 10.7 to 11.3 wt .-% or Walsroder ^® nitrocellulose AM types (Wolff Cellulosics GmbH & Co. KG, Bomlitz DE), the nitrogen content of 1 1.3 to 11.8 wt .-% or Walsroder ^® nitrocellulose E types (Wolff Cellulosics GmbH & Co. KG, Bomlitz DE) with a nitrogen content of 11.8 to 12.3 wt .-%.

Within the aforementioned cellulose nitric acid esters of certain nitrogen contents, all viscosity stages are suitable in each case. Low-viscosity cellulose nitric acid esters of different nitrogen contents are classified according to ISO 14446 into the following groups:>30A,> 3OM, ^'

> 30E. Medium-viscosity cellulose nitric esters of different nitrogen contents are classified according to ISO 14446 into the following groups: 18 E to 29 E, 18 M to 29 M, 18 A to 29 A. Highly viscous cellulose nitric esters of different nitrogen contents, corresponding to ISO 14446 are: <17 E, <17 M and <17 A.

It is also possible to use mixtures of different types of the abovementioned suitable cellulose nitric esters.

The nitrocellulose is usually supplied in a phlegmatized form in commercial form. Typical phlegmatizers are, for example, alcohols or water. The content of phlegmatizing agent is between 5 to 40 wt .-%. Nitrocelluloses which have been moistened with alcohols or water are preferably used to prepare the dispersions according to the invention. In a particularly preferred form, nitrocellulose moistened with 10 to 40% by weight of isopropanol (based on the total mass of the delivery form) is used. As examples called "Walsroder ^® nitrocellulose E 560 isopropanol 30%" or "Walsroder ^® nitrocellulose A 500 isopropanol 30%" or "Walsroder ^® nitrocellulose E560 / water 35%."

The process for preparing the dispersions of the invention may be in one or more

Stage / -n be carried out in homogeneous or multistage reaction, partially in disperse phase. After complete or partial polyaddition from a) -f), a dispersion, emulsification or dissolution step takes place. This is followed, if appropriate, by a further polyaddition or modification in disperse phase.

For the preparation of the dispersions of the invention is that of the prior art

Production of PU dispersions known acetone method used.

For the preparation of the dispersion according to the invention by the acetone process are usually the components b) to f), which may have no primary or secondary amino groups and the polyisocyanate components a) for the preparation of an isocyanate-functional polyurethane prepolymer completely or partially and optionally with a with Water-miscible but diluted with isocyanate-inert solvents and diluted to room temperature. heated in the range of 50 to 120 ⁰ C. To accelerate the isocyanate addition reaction, the catalysts known in polyurethane chemistry can be used.

Suitable solvents are immiscible with water indefinitely and have a boiling point at atmospheric pressure of 40 to 100 ⁰ C and do not react or only very slowly with the synthesis components. Particularly suitable is tetrahydrofuran and the usual aliphatic, ketofunctional solvents such as acetone, 2-butanone or tetrahydrofuran, which may be added not only at the beginning of the preparation, but optionally also in parts later. Preference is given to acetone and 2-butanone. Particularly preferred is acetone. Subsequently, the optionally not added at the beginning of the reaction components of a) - f) are added.

In the preparation of the polyurethane prepolymer, the molar ratio of isocyanate groups to isocyanate-reactive groups is 1.05 to 3.5, preferably 1.1 to 3.0, particularly preferably 1.1 to 2.5.

The reaction of the components a) - f) to the prepolymer takes place partially or completely, but preferably completely. Thus, polyurethane prepolymers containing free isocyanate groups are obtained in bulk or in solution.

After or during the preparation of the polyurethane prepolymers, if this has not yet been carried out in the starting molecules, the partial or complete salt formation of the potentially anionically dispersing groups takes place. In the case of potentially anionic groups, bases such as tertiary amines, e.g. Trialkylamines having 1 to 12, preferably 1 to 6 carbon atoms used in each alkyl radical. Examples of these are trimethylamine, triethylamine,

Methyldiethylamine, tripropylamine, N-methylmorpholine, methyldiisopropylamine, ethyldiisopropylamine and diisopropylethylamine. The alkyl radicals may, for example, also carry hydroxyl groups, as in the case of the dialkylmonoalkanol, alkyldialkanol and trialkanolamines. As a neutralizing agent also inorganic bases, such as aqueous ammonia solution or sodium or potassium hydroxide can be used. Preference is given to ammonia, triethylamine, triethanolamine, dimethylethanolamine, diisopropylethylamine, sodium hydroxide or potassium hydroxide.

The molar amount of the bases is between 50 and 125%, preferably between 70 and 100%, of the molar amount of the acid groups to be neutralized. The neutralization can also take place simultaneously with the dispersion in which the dispersing water already contains the neutralizing agent.

Subsequently, in a further process step, if not yet done or only partially done, the resulting prepolymer with the aid of aliphatic ketones such as acetone or 2-butanone. Subsequently, possible NH ₂ - and / or NH-functional components c) to e) are reacted with the remaining isocyanate groups. This chain extension / termination can be carried out either in a solvent before dispersion, during dispersion or in water after dispersion. The chain extension is preferably carried out in water before dispersion.

If compounds corresponding to the definition of e) with NH ₂ or NH groups are used for chain extension, the chain extension of the prepolymers preferably takes place before the dispersion.

The degree of chain extension, ie the equivalent ratio of NCO-reactive groups of the compounds used for chain extension to free NCO groups of the prepolymer, is between 40 and 150%, preferably between 50 and 120%, particularly preferably between 60 and 120%.

The amine components [c), d), f)] can optionally be used individually or in mixtures in water- or solvent-diluted form in the process according to the invention, wherein in principle any order of addition is possible.

When water or organic solvents are used as the diluent, the diluent content is preferably 70 to 95% by weight.

The preparation of the dispersion according to the invention from the prepolymers takes place after the chain extension. For this purpose, the dissolved and chain-extended polyurethane polymer may be subjected to high shear, such as, e.g. vigorous stirring, either added to the dispersing water or, conversely, the dispersing water is stirred into the prepolymer solutions. Preferably, the water is added to the dissolved prepolymer.

The solvent still present in the dispersions after the dispersion step is then usually removed by distillation. A removal already during the dispersion is also possible. The dispersions according to the invention generally have one

Residual solvent content of <3 wt .-%, preferably <1 wt .-% to.

The nitrocellulose is preferably dissolved in ketofunctional organic solvents such as acetone or 2-butanone prior to addition to the prepolymer (i). Most preferably, the nitrocellulose is dissolved in acetone. The content of nitrocellulose in the acetone solution is 5 to 95 wt .-%, preferably 5 to 70 wt .-% and particularly preferably 5 to 50 wt .-%. The addition of the acetone nitrocellulose solution may take place during the dissolution step after preparation of the prepolymer before (i) or after (ii) chain extension but before dispersion or after dispersion prior to distillation (iii).

Preferably, the addition of the dissolved nitrocellulose occurs after preparation of the prepolymer (i), i. before or after the chain extension step (ii), but before the dispersion (iii).

In a particularly preferred embodiment, the addition of the dissolved nitrocellulose after the chain extension step (ii) takes place before dispersion (iii).

The content of nitrocellulose in the resulting inventive dispersion, based on total solids, is 0.5% by weight to 85% by weight, preferably 5% by weight to 75% by weight, particularly preferably 10 to 60% by weight. %.

The solids content of the dispersion according to the invention is between 10 to 70 wt .-%, preferably between 20 to 65 wt .-% and particularly preferably between 30 to 63 wt .-%.

The polyurethane-nitrocellulose particles containing in the dispersions of the invention have an average particle size between 20 and 700 nm, preferably between 30 and 550 nm, more preferably between 50 and 400 nm and most preferably between 100 and

330 nm.

The dispersions of the invention may additionally contain antioxidants and / or light stabilizers and / or other auxiliaries and additives such as defoamers and thickeners. Finally, fillers, non-migratory plasticizers, pigments, silica sols, aluminum, clay dispersions, leveling agents or thixotropic agents may also be present. Depending on the desired property profile and intended use of the dispersions according to the invention, up to 70%, based on the total dry substance, of such fillers may be present in the end product.

The aqueous dispersions of the invention may e.g. be used in single-coat paints or in the clear or topcoat layer (top layer) of multi-layer structures.

The preparation of the coating can be carried out by the different spraying methods such as air pressure, airless or electrostatic spraying using single or optionally two-component spray systems. However, the paints and coating compositions containing the dispersions of the invention can also by other methods, for example by brushing, rolling, pouring, knife coating, dipping, printing or further the

State of the art known methods are applied. The present invention also relates to coating compositions containing the dispersions of the invention.

The present invention is the use of the dispersions according to the invention for the production of products in the field of cosmetics.

Another object of the present invention is the use of the invention

Dispersions for producing coated substrates.

Suitable substrates are for example woven and non-woven textiles, leather, paper, hardboard, paper-like materials, wood, glass, plastics of various kinds, ceramics, stone, concrete, bitumen, metals or glass or carbon fibers.

The novel dispersions are likewise suitable for the preparation of sizes, adhesive systems or printing inks.

The present invention furthermore relates to a substrate structure comprising one or more layers which are coated, bonded or bonded with the dispersions according to the invention.

The dispersions of the invention are stable and storable.

Examples:

Substances used and abbreviations:

Diaminosulphonate: NH ₂ -CH ₂ CH ₂ -NH-CH ₂ CH ₂ -SO ₃ Na (45% in water)

Desmophen ^® 2020 / C2200: polycarbonate polyol, OH number 56 mg KOH / g, number average

Molecular weight 2000 g / mol (Bayer MaterialScience AG, Leverkusen, DE)

PolyTHF ^® 2000: Polytetramethylenglykolpolyol, OH number 56 mg KOH / g, number average molecular weight 2000 g / mol (BASF AG, Ludwigshafen, DE)

PolyTHF ^® 1000: Polytetramethylenglykolpolyol, OH number 112 mg KOH / g, number-average number average molecular weight 1000 g / mol (BASF AG, Ludwigshafen, DE)

Polyether LB 25: monofunctional polyether based on ethylene oxide / propylene oxide number-average molecular weight 2250 g / mol, OH number 25 mg KOH / g (Bayer MaterialScience AG, Leverkusen, DE)

IPA: isopropanol

Desmodur ^® W: bis (4,4'-isocyanatocyclohexyl) methane (Bayer MaterialScience AG, Leverkusen, Germany)

• Walsroder ^® nitrocellulose E330 / EPA 30%:

Low-viscosity nitrocellulose with a nitrogen content between 11.8 and 12.3%, ISO 14446: 34 E, Wolff Cellulosics GmbH & Co. KG, Bomlitz DE

• Walsroder ^® Nitrocellulose El 160 / IPA 30%:

high-viscosity nitrocellulose with a nitrogen content of between 11.8 and 12.3%, ISO 14446: 7 E, Wolff Cellulosics GmbH & Co. KG, Bomlitz DE

• Walsroder ^® Nitrocellulose A500 / IPA 30%:

high-viscosity nitrocellulose with a nitrogen content between 10.7 to 11.3%, ISO 14446: 27A, Wolff Cellulosics GmbH & Co. KG, Bomlitz DE • Walsroder ^® nitrocellulose E560 / IPA 30%:

medium-viscosity nitrocellulose with a nitrogen content between 11.8 and 12.3%, ISO 14446: 23 E, Wolff Cellulosics GmbH & Co. KG, Bomlitz DE

• Walsroder ^® nitrocellulose E560 / water 30%

Medium viscosity nitrocellulose with a nitrogen content between 11.8% to 12.3%, ISO

14446: E23, Wolff Cellulosics GmbH & Co. KG, Bomlitz, DE

The solids contents were determined according to DIN-EN ISO 3251.

NCO contents were determined volumetrically in accordance with DIN-EN ISO 11909, unless expressly stated otherwise.

The mean particle sizes of the dispersions were determined by means of laser correlation spectroscopy measurements (Zetasizer 1000, Malvern Instruments, Malvern, UK).

The OH numbers were determined according to DIN 53240-2.

The stated nitrogen contents of the nitrocellulose in wt .-% refer to the dry matter of nitrocellulose.

Variation of nitrocellulose types:

Example 1: 10% Walsroder® ^® nitrocellulose E330 / IPA 30%

310.3 g of a difunctional polyester polyol based on adipic acid and hexanediol and neopentyl glycol (average molecular weight 1700 g / mol, OHN = 66 mg KOH / g of substance) was heated to 65.degree. Subsequently, at 65 ° C within 5 min 54.9 g of hexamethylene diisocyanate were added and stirred at 100 ⁰ C until the theoretical NCO value of

3.3% was achieved. The finished prepolymer was dissolved with 503.8 g of acetone at 5O ⁰ C and then added a solution of 20.6 g diaminosulphonate, 3.2 g of ethylenediamine and 102.7 g of water min within 5 s. The stirring time was 15 min. Was then added over 5 minutes a solution of 59.9 g Walsroder® ^® nitrocellulose E330 / IPA 30% and 145.3 g of acetone. The dispersion was carried out by adding 515.3 g of water within 10 min. In a subsequent distillation step, the removal of the solvents was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 40.9% and an average particle size of 196 nm. Example 2: 30% Walsroder® ^® nitrocellulose E330 / IPA 30%

233.8 g of a difunctional polyester polyol according to Example 1 was heated to 65 ° C. Subsequently, 41.3 g of hexamethylene diisocyanate were added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. The finished prepolymer was dissolved with 400 g of acetone at 50 ⁰ C and then a solution of

15.6 g of diaminosulfonate, 2.4 g of ethylenediamine and 77.3 g of water added within 5 min. The stirring time was 15 min. Was then added over 5 minutes a solution of 174.2 g Walsroder® ^® nitrocellulose E 330 / IPA 30% and 422.4 g of acetone. The dispersion was carried out by adding 523.7 g of water within 10 min. In a subsequent distillation step, the removal of the solvents was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 39.9% and an average particle size of 156 nm.

Example 3: 10% Walsroder ^® nitrocellulose El 160 / IPA 30%

310.3 g of a difunctional polyester polyol according to Example 1 was heated to 65 ° C. Subsequently, 54.9 g of hexamethylene diisocyanate were added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. The finished prepolymer was dissolved with 341.5 g of acetone at 50 ⁰ C and then added a solution of 20.6 g of diaminosulfonate, 3.2 g of ethylenediamine and 102.7 g of water within 5 min. The stirring time was 15 min. Subsequently, IPA 30 and 307.7 g of acetone were added within 5 minutes a solution of 59.9 g Walsroder® ^® nitrocellulose El 160 /. The dispersion was carried out by adding 515.3 g of water within 10 min. In a subsequent distillation step, the removal of the solvents was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 38.0% and an average particle size of 314 nm.

Example 4; 30% Walsroder ^® Nitrocellulose El 160 / IPA 30%

233.8 g of a difunctional polyester polyol according to Example was heated to 65 ° C. Subsequently, 41.3 g of hexamethylene diisocyanate were added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. The finished prepolymer was dissolved with 322.9 g of acetone at 50 ⁰ C and then added a solution of 20.2 g of diaminosulfonate, 2.4 g of ethylenediamine and 77.3 g of water within 5 min.

The stirring time was 15 min. Subsequently, IPA 30% and 900.7 g of acetone were added within 5 minutes a solution of 175.5 g Walsroder® ^® nitrocellulose E 1 160 /. The dispersion was carried out by adding 525.6 g of water within 10 min. In a subsequent distillation Lation step, the removal of the solvent was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 38.0% and an average particle size of 523 nm.

Example 5: 10% Walsroder® ^{Nitrocellulose} A500 / IPA 30%

310.3 g of a difunctional polyester polyol according to Example was heated to 65 ° C. Subsequently, 54.9 g of hexamethylene diisocyanate were added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. When completed, the prepolymer was dissolved at 411, 4 g of acetone at 50 ⁰ C. and subsequently a solution of 20.6 g diaminosulphonate, 3.2 g of ethylenediamine and 102.7 g of water min within 5 s. The stirring time was 15 min. Was then added over 5 minutes a solution of 59.9 g Walsroder® ^® nitrocellulose A500 / IPA 30% and 167.8 g of acetone. The dispersion was carried out by adding 515.3 g of water within 10 min. In a subsequent distillation step, the removal of the solvents was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 42.0% and an average particle size of 283 nm.

Example 6: 30% Walsroder® ^{Nitrocellulose} A500 / IPA 30%

233.8 g of a difunctional polyester polyol according to Example 1 was heated to 65 ° C. Subsequently, 41.3 g of hexamethylene diisocyanate were added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. The finished prepolymer was dissolved with 322.9 g of acetone at 50 ⁰ C and then added a solution of 20.2 g of diaminosulfonate, 2.4 g of ethylenediamine and 77.3 g of water within 5 min. The stirring time was 15 min. 30% and 491.3 g of acetone was then added over 5 minutes a solution of 175.5 g Walsroder® ^® nitrocellulose A500 / IPA. The dispersion was carried out by adding 525.6 g of water within 10 min. In a subsequent distillation step, the removal of the solvents was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 41.0% and an average particle size of 141 nm.

Variation of the nitrocellulose mass fraction in the solids content

Example 7: 20% Walsroder® ^® nitrocellulose E560 / BPA 30%

276.3 g of a difunctional polyester polyol according to Example 1 was heated to 65 ° C. Subsequently, 48.9 g of hexamethylene diisocyanate were added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. The finished prepolymer was dissolved with 381.7 g of acetone at 50 ⁰ C and then a solution of

18.4 g of diaminosulfonate, 2.4 g of ethylenediamine and 91.4 g of water added within 5 min. The stirring time was 15 min. Subsequently, within 5 min, a solution of 120.1 g Walsroder® ^® nitrocellulose E560 / IPA 30% and 428.4 g of acetone. The dispersion was carried out by adding 528.9 g of water within 10 min. In a subsequent distillation step, the removal of the solvents was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 40.0% and an average particle size of 252 nm.

Example 8: 30% Walsroder® ^® nitrocellulose E560 / IPA 30%

233.8 g of a difunctional polyester polyol according to Example 1 was heated to 65 ° C.

Subsequently, 41.3 g of hexamethylene diisocyanate were added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. The finished prepolymer was dissolved with 322.9 g of acetone at 50 ⁰ C and then a solution of

20.2 g of diaminosulfonate, 2.4 g of ethylenediamine and 77.3 g of water added within 5 min. The stirring time was 15 min. Subsequently, 30 and 696.0 g of acetone were added within 5 minutes a solution of 175.5 g Walsroder® ^® nitrocellulose E560 / IPA. The dispersion was carried out by adding 525.6 g of water within 10 min. In a subsequent distillation step, the removal of the solvents was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 41.0% and an average particle size of 160 nm.

Example 9: 40% Walsroder® ^® nitrocellulose E560 / IPA 30%

199.8 g of a difunctional polyester polyol according to Example 1 was heated to 65 ° C. Subsequently, 35.3 g of hexamethylene diisocyanate was added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. The finished prepolymer was dissolved with 276.0 g of acetone at 50 ⁰ C and then a solution of

17.3 g of diaminosulfonate, 2.0 g of ethylenediamine and 66.1 g of water added within 5 min. The stirring time was 15 min. 30% and 925.1 g of acetone was then added over 5 minutes a solution of 233.2 g Walsroder® ^® nitrocellulose E560 / IPA. The dispersion was carried out by adding 536.6 g of water within 10 min. In a subsequent distillation step, the removal of the solvents was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 40.0% and an average particle size of 261 nm.

Example 10; 50% Walsroder ^® Nitrocellulose E560 / IPA 30%

114.8 g of a difunctional polyester polyol according to Example 1 was heated to 65 ° C. Subsequently, 20.3 g of hexamethylene diisocyanate was added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. The finished prepolymer was dissolved with 240.1 g of acetone at 5O ⁰ C and then added a solution of 13.4 g of diaminosulfonate, 0.9 g of ethylenediamine and 38.0 g of water within 5 min. The stirring time was 15 min. 30% and 804.4 g of acetone was then added over 5 minutes a solution of 202.8 g Walsroder® ^® nitrocellulose E560 / IPA. The dispersion was carried out by adding 380.5 g of water within 10 min. In a subsequent distillation step, the removal of the solvents was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 42.9% and an average particle size of 172 nm.

Example 11; 60% Walsroder ^® Nitrocellulose E560 / IPA 30%

131.8 g of a difunctional polyester polyol according to Example 1 was heated to 65 ° C. Subsequently, 23.3 g of hexamethylene diisocyanate was added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. The finished prepolymer was dissolved with 275.7 g of acetone at 5O ⁰ C and then added a solution of 17.5 g of diaminosulfonate, 0.7 g of ethylenediamine and 43.6 g of water within 5 min.

The stirring time was 15 min. 30%, and 1391.1 g of acetone was then added over 5 minutes a solution of 350.7 g Walsroder® ^® nitrocellulose E560 / IPA. The dispersion was carried out by adding 560.5 g of water within 10 min. In a subsequent distillation step, the solvents were removed in vacuo and a storage-stable PUR dispersion having a solids content of 39.0% and an average particle size of 222 nm was obtained.

Process variants of nitrocellulose addition:

Example 12: 10% Walsroder® ^® nitrocellulose E560 / IPA 30% (addition of the nitrocellulose before the chain extension)

280.5 g of a difunctional polyester polyol according to Example 1 was heated to 65 ° C.

Subsequently, 49.6 g of hexamethylene diisocyanate was added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. The finished prepolymer was dissolved with 481.3 g of acetone at 50 ⁰ C and then added a solution of 61.0 g of Walsroder ^® nitrocellulose E560 / IPA 30% and 170.7 g of acetone within 5 min. Subsequently, a solution of 15.9 g of diaminosulfonate, 2.5 g of ethylenediamine and

92.8 g of water added within 5 min. The stirring time was 15 min .. The dispersion was carried out by adding 473.0 g of water within 10 min. In a subsequent distillation step, the removal of the solvents in vacuo and there was a storage - -

stable PUR dispersion having a Festköφergehalt of 37.0% and an average particle size of 269 nm.

Example 13: 20% Walsroder® ^® nitrocellulose E560 / IPA 30% (addition of the nitrocellulose before the chain extension)

276.3 g of a difunctional polyester polyol according to Example 1 was heated to 65 ⁰ C.

Subsequently, 48.9 g of hexamethylene diisocyanate were added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. The finished prepolymer was dissolved with 381.7 g of acetone at 5O ⁰ C and then a solution of

Add 120.1 g of Walsroder ^® Nitrocellulose E560 / IPA 30% and 428.4 g of acetone within 5 min. Subsequently, a solution of 18.4 g of diaminosulfonate, 2.4 g of ethylenediamine and

91.4 g of water added within 5 min. The stirring time was 15 min .. The dispersion was carried out by adding 528.9 g of water within 10 min. In a subsequent distillation step, the removal of the solvents was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 39.0% and an average particle size of 176 nm.

Example 14: 30% Walsroder® ^® nitrocellulose E560 / IPA 30%

Subsequently, 41.3 g of hexamethylene diisocyanate was added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. The finished prepolymer was dissolved with 322.9 g of acetone at 50 ⁰ C and then a solution of

174.2 g Walsroder® ^® nitrocellulose E560 / IPA 30% and 690.9 g of acetone were added within 5 min. Subsequently, a solution of 15.6 g of diaminosulfonate, 2.1 g of ethylenediamine and 77.3 g of water was added within 5 min. The stirring time was 15 min .. The dispersion was carried out by adding 523.7 g of water within 10 min. In a subsequent distillation step, the removal of the solvents was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 39.0% and an average particle size of 388 nm.

Example 15: 10% Walsroder® ^® nitrocellulose E560 / EPA 30% (addition of the nitrocellulose after dispersion)

310.3 g of a difunctional polyester polyol according to Example 1 was heated to 65 ° C.

Subsequently, 54.9 g of hexamethylene diisocyanate were added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. The finished prepolymer was dissolved with 411.4 g of acetone at 50 ⁰ C and then added a solution of 20.6 g of diaminosulfonate, 3.2 g of ethylenediamine and 102.7 g of water within 5 min. The stirring time was 15 min .. The dispersion was carried out by adding 515.3 g of water within 10 min. Then a solution of 59.9 g Walsroder® ^® nitrocellulose E560 / IPA was 30% and 297.7 g of acetone were added within 5 min. In a subsequent

Distillation step carried out the removal of the solvents in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 38.0% and an average particle size of 260 nm.

Example 16: 30% Walsroder® ^® E nitrocellulose E560 / IPA 30% (addition of the nitrocellulose after dispersion)

233.8 g of a difunctional polyester polyol according to Example was heated to 65 ° C. Subsequently, 41.3 g of hexamethylene diisocyanate were added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. The finished prepolymer was dissolved with 753.4 g of acetone at 50 ⁰ C and then added a solution of 15.6 g of diaminosulfonate, 2.4 g of ethylenediamine and 77.3 g of water within 5 min.

The stirring time was 15 min .. The dispersion was carried out by adding 523.7 g of water within 10 min. Then a solution of 174.2 g Walsroder® ^® nitrocellulose E560 / IPA 30% and 690.9 g of acetone was added over 5 min. In a subsequent distillation step, the solvents were removed in vacuo and a storage-stable PUR dispersion having a solids content of 38.0% and an average particle size of 376 nm was obtained.

OH-functional dispersions according to the invention:

Example 17: 30% Walsroder® ^® nitrocellulose E560 / IPA 30

233.8 g of a difunctional polyester polyol according to Example was heated to 65 ° C. Subsequently, 41.3 g of hexamethylene diisocyanate were added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. The finished prepolymer was dissolved with 322.9 g of acetone at 50 ⁰ C and then added a solution of 20.2 g of diaminosulfonate, 4.1 g of N- (2-hydroxyethyl) ethylenediamine and 77.3 g of water within 5 min. The stirring time was 15 min. Subsequently, a solution of 176.5 g of Walsroder® nitrocellulose E560 / IPA 30% and 700.2 g of acetone was added within 5 min.

The dispersion was carried out by adding 529.4 g of water within 10 min. In a subsequent distillation step, the removal of the solvents in vacuo and it was a storage-stable PUR dispersion having a solids content of 40.0%, a particle size of 313 nm and an OH content of 0.16 wt .-% was obtained with respect to solid resin.

Example 18: 30% Walsroder® ^® nitrocellulose E560 / EPA 30%

233.8 g of a difunctional polyester polyol according to Example 1 was heated to 65 ° C. Subsequently, 41.3 g of hexamethylene diisocyanate were added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was reached. The finished prepolymer was dissolved with 322.9 g of acetone at 50 ° C and then a solution of 20.2 g of diaminosulfonate, 5.9 g of N, N'-bis (2-hydroxyethyl) ethylenediamine and 77.3 g of water within metered in from 5 min. The stirring time was 15 min. 30% and 704.5 g of acetone was then added over 5 minutes a solution of 177.6 g Walsroder® ^® nitrocellulose E560 / EPA. The dispersion was carried out by adding 533.1 g of water within 10 min. In a subsequent distillation step, the removal of the solvent was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 41.8% and an average particle size of 289 nm and an OH content of 0.32 wt .-% with respect to solid resin ,

Nonionic-stabilized dispersion according to the invention

Example 19: 10% Walsroder® ^® nitrocellulose E560 / EPA 30%

264.4 g of Desmophen ^® C2200, 31.5 g of polyether LB 25 and 6.3 g of neopentyl glycol were heated to 65 ° C. Was and 11.3 g of isophorone diisocyanate was then added and stirred at 100 ⁰ C until the theoretical NCO value at 65 ° C within 5 min 67.9 g Desmodur ^® W reaches 2.43%. The finished prepolymer was dissolved with 434.9 g of acetone at 50 ⁰ C and then added a solution of 2.4 g of diethylenetriamine, 2.5 g of hydrazine hydrate and 15.3 g of water within 10 min. The stirring time was 5 min. Subsequently, a solution of 61.1 g of Walsroder® nitrocellulose E560 / DPA 30% and 242.5 g of acetone was added within 5 min. The dispersion was carried out by adding 625.6 g of water within 15 min. In a subsequent distillation step, the removal of the solvents was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 40.0% and an average particle size of 283 nm. Other dispersions of the invention;

Example 20: 30% Walsroder® ^® nitrocellulose E560 / IPA 30%

140.0 g of a difunctional polyester polyol based on adipic acid and hexanediol (average molecular weight 840 g / mol, OHN = 106 mg KOH / g substance), 7.7 g of trimethylolpropane and 6.5 g of 1,6-hexanediol were heated to 65.degree heated. Subsequently, at 65 ° C within

Was 5 min 99.6 g of Desmodur ^® W, 18.1 g of hexamethylene diisocyanate and 68.0 g of acetone was added and stirred under reflux until the theoretical NCO value of 4.46% was reached. The finished prepolymer was dissolved with 392.6 g of acetone at 50 ° C and then added a solution of 4.6 g of hydrazine hydrate and 20.1 g of water within 5 min. The stirring time was 5 min. Subsequently, a solution of 28.4 g of diaminosulfonate and 78.0 g of water was added within 10 min. Subsequently, a solution of 176.1 g Walsroder® ^® nitrocellulose E560 / IPA was 30% and 698.5 g of acetone. The dispersion was carried out by adding 500.9 g of water within 10 min. In a subsequent distillation step, the solvents were removed in vacuo and a storage-stable PUR dispersion having a solids content of 39.0% and an average particle size of 192 nm was obtained.

Example 21: 10% Walsroder® ^® nitrocellulose E560 / IPA 30%

252.0 g of Desmophen ^® C2200, 10.1 g of polyether LB 25, 3.2 g of neopentyl glycol and 8.8 g of dimethylaminoethyl lolpropionsäure were heated to 65 ° C. And 12.7 g of isophorone diisocyanate was then added and stirred until reached the theoretical NCO value of 2.81% as long as at 100 ⁰ C was at 65 ° C within 5 min 76.3 g of Desmodur ^® W. The finished prepolymer was dissolved with 6.5 g of triethylamine and 434.9 g of acetone at 5O ⁰ C and then lentriamin a solution of 2.7 g diethylenetriamine, 2.9 g of hydrazine hydrate and 17.2 g of water within 10 min metered , The stirring time was 5 min. The mixture was then added within 5 min harvester, a solution of 59.4 g WAIS ^® nitrocellulose E560 / EPA 30% and 235.7 g of acetone. The dispersion was carried out by adding 605.6 g of water within 15 min. In a subsequent distillation step, the removal of the solvents was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 38.0% and an average particle size of 130 nm.

Example 22: 30% Walsroder® ^® nitrocellulose E560 / EPA 30%

196.0 g of Desmophen ^® C2200, 7.9 g of polyether LB 25, 2.5 g of neopentyl glycol and 8.2 g of dimethylaminoethyl lolpropionsäure were heated to 65 ° C. Subsequently, at 65 ° C within 5 min 60.7 g of Desmodur ^® W and 11.0 g of isophorone diisocyanate was added and stirred at 100 ⁰ C until the theoretical NCO value of 2.76% was reached. The finished prepolymer was dissolved with 6.1 g of triethylamine and 450.9 g of acetone at 50 ⁰ C and then added a solution of 2.1 g diethylenetriamine, 2.2 g of hydrazine hydrate and 13.4 g of water within 10 min , The stirring time was 5 min. Subsequently, within 5 min, a solution of 181.2 g

Walsroder® ^® nitrocellulose E560 / IPA 30% and 718.8 g of acetone. The dispersion was carried out by adding 620.1 g of water within 15 min. In a subsequent distillation step, the removal of the solvents was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 40.0% and an average particle size of 310 nm.

Example 23: 20% Walsroder® ^® nitrocellulose E560 / EPA 30%

292.5 g of a difunctional polyester polyol based on adipic acid and 1,4-butanediol (average molecular weight 2250 g / mol, OH number = 50 mg KOH / g of substance) were heated to 65.degree. Subsequently, at 65 ° C within 5 min 19.7 g of 1, 6-hexamethylene diisocyanate and 13.0 g of isophorone diisocyanate was added and stirred at 80 ⁰ C until the theoretical

NCO value of 1.18% was reached. The finished prepolymer was dissolved with 300.0 g of acetone at 50 ⁰ C and then added a solution of 1.7 g of diethanolamine, 8.5 g of diaminosulfonate and 51.0 g of water within 10 min. The stirring time was 60 min. 30% and 468.4 g of acetone was then added over 5 minutes a solution of 118.1 g Walsroder® ^® nitrocellulose E560 / IPA. The dispersion was carried out by adding 564.3 g of water within

15 minutes. In a subsequent distillation step, the removal of the solvents was carried out in vacuo and there was obtained a storage-stable PUR dispersion having a solids content of 40.0% and an average particle size of 243 nm.

Example 24: 40% Walsroder® nitrocellulose E560 / water 30% 212.5 g of a difunctional polyester polyol based on adipic acid and hexanediol and

Neopentyl glycol (average molecular weight 1700 g / mol, OHN = ca. 66 mg KOH / g substance) was heated to 65 ° C. Subsequently, 37.6 g of hexamethylene diisocyanate was added at 65 ° C within 5 min and stirred at 100 ⁰ C until the theoretical NCO value of 3.3% was exceeded. The finished prepolymer was dissolved with 375 g of acetone at 50 ⁰ C and then a solution of 20.2 g of diaminosulfonate, 2.2 g of ethylenediamine and 90.0 g

Water added within 5 min. The stirring time was 15 min. Subsequently, a solution of 268.0 g of Walsroder® nitrocellulose E560 / H2O 30%, a medium-viscosity nitrocellulose with a nitrogen content of between 11.8 and 12.3%, ISO 14446: 23, was obtained within 5 minutes E, and 893.4 g of acetone were added and stirred for 30 minutes. The dispersion was carried out by adding 458.4 g of water within 10 min. In a subsequent distillation step, the solvents were removed in vacuo and a storage-stable PUR dispersion having a solids content of 41.0% and an average particle size of 279 nm was obtained.

Claims

claims

1. Aqueous dispersions containing polyurethane-nitrocellulose particles with a particle size of 20 to 700 nm, which has a polyurethane content, which compounds as components of the group

a) the organic polyisocyanates,

b) the polyols having number average molecular weights of 400 to 8000 g / mol and having an OH functionality of 1, 5 to 6,

c) the low molecular weight compounds of molecular weight 62 to 400 g / mol, which have two or more hydroxyl and / or amino groups,

d) the low molecular weight compounds which have a hydroxyl or amino group,

f) contains the isocyanate-reactive, nonionic hydrophilic compounds

and a proportion of water-insoluble nitrocellulose.

2. Aqueous dispersions according to claim 1, characterized in that the nitrocellulose has a nitrogen content of 10.7 to 12.6 wt .-%, based on dry matter of the nitrocellulose having.

3. Aqueous dispersions according to claim 1, characterized in that the polyols b) polyester polyols or hydroxyl-containing polycarbonates of molecular weight Mn from 400 to 6000 g / mol.

4. Aqueous dispersions according to claim 1, characterized in that the polyols b) are hexanediol adipic acid ester, butanediol adipic acid ester, hexanediol neopentyl glycol adipic acid ester, butanediol adipic acid ester and hexanediol phthalate.

5. Aqueous dispersions according to claim 1, characterized in that the nitrocellulose with 10 to 40 wt .-% isopropanol (based on the total mass of the delivery form) is moistened.

6. A process for the preparation of the aqueous dispersion according to claim 1, characterized in that the synthesis components containing compounds selected from the group

a) the organic polyisocyanates,

b) the polyols having number average molecular weights of 400 to 8000 g / mol and having an OH functionality of 1.5 to 6,

d) the low molecular weight compounds which have a hydroxyl or amino group,

f) the isocyanate-reactive, nonionically hydrophilicizing compounds,

be implemented so that first a urea group-free, isocyanate-functional prepolymer (i) is prepared, (Process according to claim 6, characterized in that the molar ratio of isocyanate groups to isocyanate-reactive groups

1.05 to 3.5), then the remaining isocyanate groups are amino-chain extended or terminated (ii) and the nitrocellulose dissolved in acetone or

2-butanone after preparation of the prepolymer (i) or after chain extension (ii) but before dispersion or after dispersion (iii) is added prior to distillation.

7. The method according to claim 6, characterized in that the nitrocellulose is dissolved in acetone before addition to the prepolymer.

8. The method according to claim 6, characterized in that the addition of the nitrocellulose after preparation of the prepolymer (i) or after the chain extension step (ii), but before the dispersion (iii) takes place.

9. The method according to claim 6, characterized in that the addition of the dissolved nitrocellulose after the chain extension step (ii) before the dispersion (iii) takes place.

10. Coating composition containing aqueous dispersions according to claim 1.

11. Use of the aqueous dispersions according to claim 1 for the preparation of coated substrates.

12. Use of the aqueous dispersions according to claim 1 for the preparation of sizes, adhesive systems or printing inks.

13. Use of the aqueous dispersions according to claim 1 for the production of products in the field of cosmetics.

14. Substrate structure comprising one or more layers which are coated, bonded or bonded with aqueous dispersions according to claim 1.