DE19922377A1 - Production of aqueous polyurethane-polyurea dispersion, used as coating material or adhesive, involves reacting isocyanate prepolymer with mixture of aliphatic ketone or aldehyde and polyamino compound - Google Patents

Abstract

Aqueous polyurethane-polyurea dispersions are produced by making a polyurethane prepolymer with hydrophilic groups and isocyanate groups, reacting this with a mixture (M) of an aliphatic ketone or aldehyde and an amine (A1) with at least 2 primary and/or secondary amino groups and then dispersing the mixture obtained in water. An Independent claim is also included for aqueous dispersions of polyurethane-polyurea obtained by this process.

Description

The present invention relates to a process for the preparation of aqueous dispersion comprising a polyurethane polyurea by

• A) a poly carrying hydrophilic groups and isocyanate groups manufactures urethane prepolymer;
• B) the polyurethane prepolymer with a mixture (M) of one aliphatic ketone or aldehyde and an amine, the minde at least 2 amino groups selected from the group of primary and secondary amino groups, carries, mixes; and
• C) the reaction mixture formed in step (II) in water dispersed.

The invention further relates to aqueous polyurethane polyurea Material dispersions that can be produced by this process as well as their use, e.g. B. as an adhesive, impregnating and Be layering agent.

Polyurethane dispersions are generally known. A good one leadership offers z. B. Plastic Handbook, Vol. 7, 3rd edition. For the coating application area, the coatings should be good mechanical properties such as high tensile strength and high Exhibit hardness. Furthermore, the dispersions should clear themselves Films that are as free as possible from cloudiness or other disturbances len are processed.

The hardness of the PU dispersions can, as is generally known, by the installation of short-chain NCO-reactive connections like simple ones Polyols or polyamines can be increased.

• 1. If polyols are to be used, they become more common in bulk or in suitable solvents in a homogeneous Phase reacted with the isocyanates. One leads through this reaction with HDI as isocyanate, so one puts found that either - when using linear polyols such. B. Butanediol-1,4 - crystalline urethanes are formed which insta lead, settling dispersions or that - at  Use of branched polyols such as B. Neopentyl glycol - the Hardness is not increased to the desired extent.
• 2. If polyamines are to be used, a is usually used Produced NCO group-carrying, hydrophilic prepolymer, this dispersed in water and the polyamines of the dispersion added and reacted in a heterogeneous phase.

This procedure is based on the fact that amines are used Isocyanate are very reactive and, if they are analogous to the poly olen wants to implement, the reaction is very exothermic and is therefore difficult to master and secondly through Subsequent reactions of the ureas formed (e.g. to the biuret) Trü exercises arise that affect the film properties or that even crosslinking of the prepolymer occurs.

The disadvantage of this procedure in the heterogeneous phase is that always in competition with the NCO-amine reaction, the reaction between Isocyanate and water takes place. The relationship of Ge speeds of the amine and water reactions depend on vie Various parameters such as B. feed rate, temperature, Agitation intensity, particle size of the prepolymer dispersion, etc. and is therefore difficult to perform reproducibly. Moreover Precipitation often occurs, especially when you have high Wants to introduce concentrations of urea, d. H. one with high NCO concentrations in the prepolymer.

EPA 000 029 describes a process for producing PUR Known dispersions in which prepolymers containing NCO groups blocked polyamines by reaction of polyamines with Obtain ketones or aldehydes to ketimines (or aldimines) are mixed in the absence of water and then in Water can be dispersed. It is essential that the Ket imines are free of water (EP 29, p. 16, lines 10-14).

However, the dispersions produced by this process are nor, as far as their mechanical properties are concerned, ver in need of improvement, especially what the tear tension from it films produced concerns. In addition, the manufacture of the ket imine or aldimine is technically complex.

From EP-A-319 816 it is known to carry hydrophilic groups NCO-functional PUR prepolymers with mixtures of water, poly to add amine and ketone, this mixture being a coherent has organic phase. For this, the mixture of water, Polyamine and ketone on the one hand and the prepolymer on the other With the help of two-component spray guns directly onto the substrate  applied. This method is expensive in terms of equipment and is only in applicable in special cases.

The task was therefore to use it as simply as possible To provide dispersions that can be produced as varnish usable and especially for coatings with high hardness and can be processed with high transparency.

The dispersions of the invention can be prepared by

• A) a poly carrying hydrophilic groups and isocyanate groups manufactures urethane prepolymer;
• B) the polyurethane prepolymer with a mixture (M) of one aliphatic ketone and an amine containing at least 2 amino groups selected from the group of primary and secondary ren amino groups, carries, mixed and thereby to a poly converts urethane polyurea; and
• C) the polyurethane polyurea dispersed in water.

In general, the procedure is to get out

• a) diisocyanates with 4 to 30 carbon atoms,
• b) diols, of which
  • 1. 10 to 100 mol%, based on the total amount of diols (b), have a molecular weight of 500 to 5000, and
  • 2. 0 to 90 mol%, based on the total amount of diols (b), have a molecular weight of 60 to 500 g / mol,
• c) monomers different from monomers (a) and (b) with we at least one isocyanate group or at least one alcohol Lischen hydroxyl group, which in addition at least one hy drophile group or a potentially hydrophilic group tra gene, whereby the water dispersibility of the polyurethanes be will work
• d) optionally further ver of the monomers (a) to (c) different multivalent compounds with reactive groups, which are alcoholic hydroxyl groups, primary or secondary amino groups or isocyanate groups and  
• e) optionally different from the monomers (a) to (d) monovalent compounds with a reactive group in which it is an alcoholic hydroxyl group, primary or se secondary amino group or an isocyanate group.

a poly carrying hydrophilic groups and isocyanate groups urethane prepolymer (hereinafter referred to as "prepolymer") poses.

In the field of polyurethane chemistry, it is well known how the molecular weight of the polyurethanes by choosing the proportions of the mutually reactive monomers and the arithmetic mean the number of reactive functional groups per molecule can be put. The NCO content of the prepolymer depends according to the amount of urea units which the polyurethane Po should contain lyurea. Generally the NCO content is of the prepolymer 0.4 to 10 wt .-% (based on the solution medium-free prepolymer).

The starting materials that are used to build the prepolymer are generally used in such proportions that after all alcoholic hydroxyl groups have reacted, the Prepolymer has the above-mentioned NCO content.

The monomers (a) which are usually used in polyurethane Chemistry used diisocyanates.

Particular mention should be made of diisocyanates X (NCO) ₂ , where X represents an aliphatic hydrocarbon radical having 4 to 12 carbon atoms, a cycloaliphatic or aromatic carbon hydrogen radical having 6 to 15 carbon atoms or an araliphatic hydrocarbon radical having 6 to 15 carbon atoms. Examples of such diisocyanates are tetra methylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,4-diisocyanatocyclohexane, 1-isocyanato-3,5,5-tri methyl-5-isocyanatomethylcyclohexane (IPDI), 2,2-bis (4-iso cyanatocyclohexyl) propane, bis- (isocyanatomethyl) cyclohexane, trimethylhexane diisocyanate, 1,4-diisocyanatobenzene, 2,4-diisocyanato-toluene, 2,6-diisocyanatotoluene, 4,4'-diisocyanato-diphenylmethane, 2,4'-diisocyanato-diphenylmethane, p-xylylene diisocyanate, tetra methylxylylene diisocyanate (TMXDI), the isomers of bis- (4-iso-cyanatocyclohexyl) methane (HMDI) such as the trans / trans, the cis / cis and the cis / trans isomer and consisting of these compounds Mixtures.

Mixtures of these are, in particular, mixtures of these isocyanates respective structural isomers of diisocyanatotoluene and diisocya nato-diphenylmethane important; especially the mix from 80 mol% 2,4 diisocyanatotoluene and 20 mol% 2,6-diiso suitable for cyanatotoluene. Furthermore, the mixtures of aroma table isocyanates such as 2,4 diisocyanatotoluene and / or 2,6-diisocyanatotoluene with aliphatic or cycloaliphatic Isocyanates such as hexamethylene diisocyanate or IPDI especially before partial, the preferred mixing ratio of the aliphati to aromatic isocyanates is 4: 1 to 1: 4.

As compounds (a) it is also possible to use isocyanates which are ne ben the free isocyanate groups further blocked isocyanate groups, e.g. B. uretdione groups, or carbodiimide groups.

With regard to good film formation and elasticity come as diols (b) primarily higher molecular weight diols (b1), which a Molecular weight from about 500 to 5000, preferably from about Have 1000 to 3000 g / mol.

The diols (b1) are in particular polyester polyols which, for. B. from Ullmann's encyclopedia of technical chemistry, 4th edition, volume 19, pages 62 to 65 are known. Polyester polyols are preferably used which are obtained by reacting dihydric alcohols with dihydric carboxylic acids. 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 or their mixtures for the preparation of the polyester polyols. The polycarboxylic acids can be aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic and optionally, e.g. B. by halogen atoms, substituted and / or unsaturated. Examples include: suberic acid, azelaic acid, phthalic acid, isophthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endo methylene tetrahydrophthalic anhydride, glutaric anhydride; Maleic acid, maleic anhydride, alkenyl succinic acid (anhydride), fumaric acid, dimeric fatty acids. Preferred are dicarboxylic acids of the general formula HOOC- (CH ₂ ) _y -COOH, where y is a number from 1 to 20, preferably an even number from 2 to 20, e.g. B. succinic acid, adipic acid, dodecanedicarboxylic acid and sebacic acid.

As polyhydric alcohols such. B. ethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,3-diol, butene-1,4-diol, butyne-1,4-diol, pentane-1,5- diol, neopentyl glycol, bis (hydroxy methyl) cyclohexanes such as 1,4-bis (hydroxymethyl) cyclohexane, 2-methyl propane-1,3-diol, methyl pentanediols, also diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, Polypropylene glycol, dibutylene glycol and poly butylene glycols into consideration. Alcohols of the general formula HO- (CH ₂ ) _x -OH are preferred, where x is a number from 1 to 20, before being an even number from 2 to 20. Examples include ethylene glycol, butane-1,4-diol, hexane-1,6-diol, octane-1,8-diol and dodecane-1,12-diol. Neopentyl glycol and 1,5-pentanediol are further preferred.

Also come polycarbonate diols, such as z. B. by implementation of phosgene with an excess of that as build-up components for the low molecular weight polyester polyols Alcohols can be obtained.

Lactone-based polyester diols are also suitable, which are homopolymers or copolymers of lactones, preferably end products which have hydroxyl groups and which are end products of lactones with suitable difunctional starter molecules. Suitable lactones are preferably those which are derived from compounds of the general formula HO- (CH ₂ ) _z -COOH, where z is a number from 1 to 20 and an H atom of a methylene unit also by a C ₁ - to C ₄ -alkyl radical may be substituted. Examples are epsilon-caprolactone, β-propiolactone, γ-butyrolactone and / or methyl-epsilon-caprolactone and mixtures thereof. Appropriate starter components are e.g. B. the above-mentioned as a building component for the polyester polyols low molecular weight dihydric alcohols. The corresponding polymers of epsilon caprolactone are particularly preferred. Lower polyester diols or polyether diols can also be used as starters for the preparation of the lactone polymers. Instead of the polymers of lactones, the corresponding chemically equivalent polycondensates of the hydroxy carboxylic acids corresponding to the lactones can also be used.

In addition, the monomers (b1) are polyether diols. They are in particular by polymerization of ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin with themselves, for. B. in the presence of BF ₃ or by Anla approximation of these compounds, optionally in a mixture or one after the other, on starting components with reactive hydrogen atoms, such as alcohols or amines, for. B. water, ethylene glycol, propane-1,2-diol, propane-1,3-diol, 1,2-bis (4-hydroxydi phenyl) propane or aniline available. Polytetrahydrofuran with a molecular weight of 240 to 5000 and especially 500 to 4500 is particularly preferred.

Polyhydroxyolefins are also suitable, preferably those with 2 terminal hydroxyl groups, e.g. B. α-ω-dihydroxypolybutadiene, α-ω-Dihydroxypolymethacrylester or α-ω-Dihydroxypolyacrylester as monomers (c1). Such connections are made, for example known from EP-A-0622378. Other suitable polyols are poly acetals, polysiloxanes and alkyd resins.

The polyols can also be used as mixtures in a ratio of 0.1: 1 to 1: 9 can be used.

In addition to the introduction of the urea groups, the hardness and the elastic modulus of the polyurethanes are further increased, in addition to the diols (b1) as low-molecular weight diols (b) Diols (b2) with a molecular weight of about 62 to 500, preferably from 62 to 200 g / mol.

Above all, the structural components of the for monomers (b2) the production of short-chain polyester polyols Alkanediols used, the unbranched diols with 2 to 12C atoms and an even number of C atoms as well Pentane-1,5-diol are preferred.

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

In order to achieve the water dispersibility of the polyurethanes, are the polyurethanes in addition to components (a), (b), (d) and (e) from mono different from components (a), (b), (d) and (e) meren (c), the at least one isocyanate group or at least an alcoholic hydroxyl group or an amine NH group and moreover at least one hydrophilic group or one Group that can be converted into a hydrophilic group, tra gen, built. In the following text the term "hydrophilic Groups or potentially hydrophilic groups "with" (potentially) hy drophilic groups ". The (potentially) hydrophilic groups react with isocyanates much more slowly than the function nellen groups of the monomers that build the polymer backbone serve.

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

The (potentially) hydrophilic groups cannot be ionic or preferably around (potentially) ionic hydrophilic group pen act.

Polyalkylene oxide Re come as nonionic hydrophilic groups ste, in particular polyethylene glycol ether from preferably 5 to 100, preferably 10 to 80 repeating ethylene oxide units, in Consideration. The content of polyethylene oxide units is general 0 to 10, preferably 0 to 6 wt .-%, based on the Weight amount of all monomers (a) to (e).

Preferred monomers with nonionic hydrophilic groups are Polyethylene oxide diols, polyethylene oxide monools and the reaction products from a polyethylene glycol and a diisocyanate, the carry a terminally etherified polyethylene glycol residue. Derar term diisocyanates and processes for their preparation are in the patents US 3 905 929 and US 3 920 598.

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

Potentially ionic hydrophilic groups are primarily those that by simple neutralization, hydrolysis or quaterni sation reactions in the above-mentioned ionic hydrophilic Have groups transferred, e.g. B. carboxylic acid groups, Anhydride groups or tertiary amino groups.

(Potentially) ionic monomers (c) are e.g. B. in Ullmanns Encyclopedia of Technical Chemistry, 4th Edition, Volume 19, Pp. 311-313 and for example in DE-A 14 95 745 in detail described.

Suitable monomers with (potentially) anionic groups are usually aliphatic, cycloaliphatic, araliphatic or aromatic carboxylic acids and sulfonic acids which carry at least one alcoholic hydroxyl group or amine NH group. Dihydroxyalkylcarboxylic acids are preferred, especially with 3 to 10 carbon atoms, as are also described in US Pat. No. 3,412,054. In particular, compounds of the general formula

in which R ¹ and R ^{2 is} a C ₁ - to C ₄ -alkanediyl unit and R ^{3 is} a C ₁ - to C ₄ -alkyl unit and especially dimethylol propionic acid (DMPA) is preferred.

Corresponding dihydroxysulfonic acids and Dihydroxyphosphonic acids such as 2,3-dihydroxypropanephosphonic acid.

As monomers (c) with amino groups reactive towards isocyanates come aminocarboxylic acids such as lysine, β-alanine, which in the DE-A-20 34 479 adducts of aliphatic diprimary Di amines on α, β-unsaturated carboxylic or sulfonic acids into consideration.

Such compounds obey, for example, the formula (c1)

H ₂ NR ⁴ -NH-R ⁵ -X (c1)

in the
-R ⁴ and R ⁵ independently of one another for a C ₁ to C ₆ alkanediyl unit, preferably ethylene
and X represents COOH or SO ₃ H.

Particularly preferred compounds of formula (c1) are N- (2-aminoethyl) -2-aminoethane carboxylic acid and the as well as the N- (2-aminoethyl) -2-aminoethanesulfonic acid or the corresponding Alkali salts, Na being particularly preferred as the counter ion.

The adducts of the abovementioned are also particularly preferred aliphatic diprimary diamines on 2-acrylamido-2-methylpropane sulfonic acid as z. B. are described in D 19 54 090.

If monomers with potentially ionic groups are used which can be converted into the ionic form before, during, but preferably after the isocyanate polyaddition, because the ionic monomers in the reaction mixture often only difficult to solve. The carboxylate or are particularly preferably Sulphonate groups in the form of their salts with an alkali ion or an ammonium ion as a counter ion.  

The monomers (d) differ from the monomers (a) to (c) are generally used for crosslinking or chains renewal. There are generally no more than two-valued ones phenolic alcohols, amines with 2 or more primary and / or se secondary amino groups as well as compounds in addition to one or several alcoholic hydroxyl groups one or more primary and / or wear secondary amino groups.

Alcohols with a higher valence than 2, for adjustment a certain degree of branching or networking NEN, z. B. trimethylolpropane, glycerin or sugar.

Suitable amines are generally polyfunctional amines Molecular weight range from 32 to 500 g / mol, preferably from 60 up to 300 g / mol, which selected at least two amino groups from the group of primary and secondary amino groups Examples of this are diamines such as diaminoethane and diamino propanes, diaminobutanes, diaminohexanes, piperazine, 2,5-dimethyl piperazine, amino-3-aminomethyl-3,5,5-trimethyl-cyclohexane (Iso phorondiamine, IPDA), 4,4'-diaminodicyclohexylmethane, 1,4-diamino cyclohexane, aminoethylethanolamine, hydrazine, hydrazine hydrate or Triamines such as diethylenetriamine or 1,8-diamino-4-aminomethyl octane.

For the same purpose, three and higher quality isocyanates are used. Commercial Compounds are, for example, isocyanurate or biuret of hexamethylene diisocyanate.

Monomers (e) which may also be used are monoiso cyanates, monoalcohols or amines with a primary or secondary ren amino group. In general, their share is a maximum of 10 mol%, based on the total molar amount of the monomers. This mono Functional connections usually carry additional functions nelle groups such as olefinic groups or carbonyl groups and are used to introduce functional groups into the poly urethane, the dispersion or crosslinking or other enable polymer-analogous implementation of the polyurethane. In Be For this purpose, monomers such as isopropenyl-alpha, alpha-dime are used thylbenzyl isocyanate (TMI) and esters of acrylic or methacrylic acid such as hydroxyethyl acrylate or hydroxyethyl methacrylate.

Monomers (d) and (e) with amino groups are generally only used in minor quantities. The molar ratio of the primary and secondary amino groups of the amines, which are used to manufacture The prepolymers are used to primary and secondary där amino groups of the amines used to prepare the mixture  (M) used is generally less than 10 mol%.

The polyaddition of components (a) to (e) generally takes place mean at reaction temperatures of 20 to 180 ° C, preferably 50 up to 150 ° C under normal pressure or under autogenous pressure.

The required response times can be a few minutes extend to a few hours. It is in the field of Polyurethane chemistry is known as the reaction time by a lot number of parameters such as temperature, concentration of the monomers, Reactivity of the monomers is influenced.

To accelerate the reaction of the diisocyanates, the usual catalysts, such as dibutyltin dilaurate, stannous octoate or diazabicyclo- (2,2,2) octane.

As polymerizers for performing steps I, II and III are stirred kettles, especially if by using solvents for a low viscosity and good heat dissipation is ensured.

Preferred solvents are infinitely miscible with water, have a boiling point at normal pressure of 40 to 100 ° C and do not react or react only slowly with the monomers.

To prepare the mixture (M) with which the prepolymers are made an amine containing at least 2 amino groups, selected from the group of primary and secondary amino groups pen, carries or mixtures of these amines. Are particularly suitable aliphatic amines, especially diamines.

Particularly preferred amines are ethylene diamine, tetramethylene diamine, hexamethylene diamine, propylene diamine, the isomer mixture of 2,2,4- and 2,4,4-trimethylhexamethylene diamine, 1,3- and 1,4-xylylenediamine, bis- (2-aminoethyl) - amine and methyl bis (3-aminopropyl) amine and the amines with the following structural formulas

As aldehydes or ketones which are used to prepare the mixtures (M) are used, especially those with 2 to 8, preferably 3 to 6 carbon atoms, e.g. B. acetaldehyde, propionaldehyde, Butyraldehyde, isobutyraldehyde, acetone, methyl ethyl ketone, methyl isobutyl ketone, diisopropyl ketone, cyclopentanone and cyclohexanone or mixtures thereof.  

The mixtures (M) are expediently prepared by the son the ketone or the aldehyde and the amine in the absence Auxiliary or solvent at 10 to 100 ° C at normal pressure mixed. The mixing ratio is generally so chooses that on 1 mol groups selected from the group of pri polar and secondary amino groups, at least 0.2, preferably 1 to 20, particularly preferably 1 to 10 mol of carbonyl groups in Ke clay or aldehyde function come.

The mixing is not critical and can be done for example conditions that one gives a mixture component to the other and ver stirs.

As a further mixture component for the production of the mixtures (M) water can optionally be used. Is preferred however, no water or no more than 1 mole of water per mole Aldehyde or ketone used.

The mixtures (M) can already immediately after the Vermi who mix the mixture components with the prepolymer the. The mixture (M) is preferably mixed with the Prepolymer, however, only after more than 1 min after mixing of the mixture components.

It is believed that immediately after mixing the Mix components part of the amino and carbonyl groups spontaneously to form imine groups in a condensation reaction occur so that the mixture (M) in the form of a mixture of unum set amine and ketone or aldehyde and partially or fully there is always iminized aldehyde or ketone.

The prepolymer and the blend (M) are mixed by for example, the mixture (M) is stirred into the prepolymer and 1 to 60, preferably 1 to 30 min at 10 to 80, preferably 20 to 60 ° C to a polyurethane polyurea.

The polyurethane polyurea is then dispersed in water yaws, for example by introducing water with stirring.

In addition to the installation of the urea groups in the polyurethane bottom lyurea over the mixtures (M) it is possible in one Step IV to generate additional urea groups by following the in Step (I) and (II) produced reaction mixture, if it is still carries free isocyanate groups during or after the dispersion in water with amines selected from at least 2 groups the group of primary and secondary amino groups. For this purpose, the amines are either added to the dispersing water  or the dispersion after dispersing with the amines transferred.

Amines suitable for this purpose are those which are also used as monomers (d) Structure of the prepolymer are recommended. This approach is particularly recommended when higher than difunctional Amines are to be used.

In this case, the molar ratio is expediently the isocyanate groups of the polyurethane produced in step I. prepolymers to the primary and secondary amino groups of the Amines which are used to prepare the mixture (M), 5: 1 to 1.01: 1.

The molar ratio of the primary and secondary amino groups the amines used in Step IV to the primary ones and secondary amino groups of the amines which are used to prepare the Mixture (M) are used, is preferably 0: 1 to 2: 1 particularly preferably 0: 1 to 1: 1.

Usually, if in the production of the polyurethane Po a solvent was used, the largest Part of the solvent is then removed from the dispersion, for example by distillation under reduced pressure. Before the dispersions have a solvent content of few less than 10 wt .-% and are particularly preferably free of Lö solvents.

The dispersions generally have a solids content of 10 to 75, preferably 20 to 65 wt .-% and a viscosity of 10 to 500 m.Pas (measured at a temperature of 20 ° C and a shear rate of 250 s ^-1 ).

The polyurethane-polyurea dispersions thus produced can NEN auxiliary agents and additives such as blowing agents, defoamers, Emulsifiers, thickeners and thixotropic agents, colorants how dyes and pigments are added.

The polyurethane-polyurea dispersions according to the invention are particularly easy to manufacture and are suitable due to their gu mechanical properties and their high hardness as a binder for the production of paints.  

Experimental part example 1

400 g (0.200 mol) of a polyesterol from adipic acid, neopentyl glycol and 1,6-hexanediol with an OH number of 56 and 20.1 g (0.150 mol) DMPA were pre-mixed with 70 g acetone in a stirred kettle placed and for 40 min at 95 ° C with 149.5 g (0.890 mmol) HDI implemented. The mixture was then cooled to 30 ° C. and with 530 g Diluted acetone. The NCO content of the solution was 3.87% by weight (calculated: 3.88% by weight). For this, a solution of 71.5 g (0.420 mol) of IPDA is added to 150 g of acetone, the temperature rose to 47 ° C. After 5 minutes, 15.0 g (0.148 mol) of triethyl amine and 800 g of water stirred in. After a further 5 min 8.2 g (0.08 mol) of DETA was stirred into 200 g of water. To Distillation of the acetone became a speck-free, approx. 40% by weight obtain aqueous PUD.

A cast film obtained from the dispersion was completely clear.

Example 2

400 g (0.200 mol) of a polyesterol from adipic acid, neopentyl glycol and 1,6-hexanediol with an OH number of 56 and 20.1 g (0.150 mol) DMPA were pre-mixed with 70 g acetone in a stirred kettle placed and for 40 min at 95 ° C with 149.5 g (0.890 mmol) HDI implemented. The mixture was then cooled to 30 ° C. and with 530 g Diluted acetone. The NCO content of the solution was 3.87% by weight (calculated: 3.88% by weight). For this, a solution of 71.5 g (0.420 mol) IPDA in 150 g cyclopentanone, the Temperature rose to 46 ° C. After 5 minutes, 15.0 g (0.148 mol) Triethylamine and 800 g of water stirred in. After another 5 min 8.2 g (0.08 mol) of DETA were stirred into 200 g of water. To Distillation of the acetone became a speck-free, approx. 40% by weight obtain aqueous PUD.

A cast film obtained from the dispersion was completely clear.

Example 3

400 g (0.200 mol) of a polyesterol from adipic acid, neopentyl glycol and 1,6-hexanediol with an OH number of 56 and 20.1 g (0.150 mol) DMPA were pre-mixed with 150 g acetone in a stirred kettle placed and for 40 min at 95 ° C with 121.1 g (0.720 mmol) HDI implemented. The mixture was then cooled to 30 ° C. and 450 g Diluted acetone. The NCO content of the solution was 2.76% by weight. (calculated: 2.72% by weight). A solution of 42.5 was used  g (0.250 mol) IPDA added to 41.7 g butanone. After 5 min 12.0 g (0.119 mol) of triethylamine and 700 g of water were stirred in. After a further 5 minutes, 8.2 g (0.08 mol) of DETA were added to 200 g of water stirred in. After the acetone was distilled, one was spotted obtain free, about 40% by weight aqueous PUD.

Comparative Example 1 (addition of pure IPDA)

The procedure was as in the example, but the IPDA was not thinly added. Immediately after the IPDA was added white precipitate that continues even during the further steps no longer dissolved.

The dispersion had a large number of specks.

A cast film obtained from the dispersion was whitish-cloudy.

Comparative Example 2 (addition of IPDA in THF)

The procedure was as in the example, but the IPDA was resolved added in 150 g of THF. Formed immediately after the addition of the IPDA a white precipitate, which continues even during the rest Steps no longer resolved.

The dispersion had a large number of specks.

A cast film obtained from the dispersion was whitish-cloudy.

Comparative Example 3

400 g (0.200 mol) of a polyesterol from adipic acid, neopentyl glycol and 1,6-hexanediol with an OH number of 56 and 20.1 g (0.150 mol) DMPA were pre-mixed with 70 g acetone in a stirred kettle placed and for 40 min at 95 ° C with 149.5 g (0.890 mmol) HDI implemented. The mixture was then cooled to 30 ° C. and with 530 g Diluted acetone. The NCO content of the solution was 3.87% by weight (calculated: 3.88% by weight). After 5 minutes, 15.0 g (0.148 mol) of triethylamine and 800 g of water are stirred in. After another 5 min. 71.5 g (0.420 mol) IPDA and 8.2 g (0.08 mol) DETA in 200 g of water are stirred in. After distillation of the acetone, a speck-free, about 40% by weight aqueous PUD obtained.

A cast film obtained from the dispersion was whitish-cloudy.  

Comparative Example 4

The procedure was as in Example 3, but instead of Solution of IPDA in butanone 68.4 g (0.250 mol) of the bis-ketimine from IPDA and butanone.

Testing the mechanical properties

Dispersions of Example 3 and Comparative Example 4 were poured onto glass plates and left to dry at room temperature for 48 hours. A tensile test according to DIN 53504 was carried out on the films thus obtained.

It can be seen that a 15% higher tensile strength is obtained.

Abbreviations

PUD = polyurethane-polyurea dispersion
RT = room temperature
OH number = hydroxyl number
ADS = adipic acid
B14 = 1,4-butanediol
HDI = hexamethylene diisocyanate
DBTL = dibutyltin dilaurate
DMPA = dimethylol propionic acid
FG = solids content
IPDA = isophoronediamine
DETA = diethylene triamine

Claims (12)

1. A process for producing an aqueous dispersion containing a polyurethane polyurea by

• A) produces a polyurethane prepolymer carrying hydrophilic groups and isocyanate groups;
• B) the polyurethane prepolymer is mixed with a mixture (M) of an aliphatic ketone or aldehyde and an amine which carries at least 2 amino groups selected from the group of primary and secondary amino groups; and
• C) the reaction mixture formed in step (II) is dispersed in water.

2. The method according to claim 1, characterized in that the I prepolymer containing hydrophilic groups and isocyanate groups is composed essentially of

• a) diisocyanates with 4 to 30 carbon atoms,
• b) diols, of which
  • 1. 10 to 100 mol%, based on the total amount of diols (b), have a molecular weight of 500 to 5000, and
  • 2. 0 to 90 mol%, based on the total amount of diols (b), have a molecular weight of 60 to 500 g / mol,
• c) Monomers different from the monomers (a) and (b) with at least one isocyanate group or at least one alcoholic hydroxyl group or a primary or secondary amino group, which in addition carry at least one hydrophilic group or a potentially hydrophilic group, which makes the polyurethane more water dispersible is caused
• d) optionally further from the monomers (a) to (c) different polyvalent compounds with reactive groups, which are alcoholic hydroxyl groups, primary or secondary amino groups or isocyanate groups and
• e) optionally from the monomers (a) to (d) different monovalent compounds having a reactive group which is an alcoholic hydroxyl group, primary or secondary amino group or an isocyanate group.

3. The method according to claim 1 or 2, characterized in that the prepolymer prepared in step I immediately before Mixing with the mixture (M) has an NCO content of 0.4 to Has 10 wt .-%. 4. The method according to claims 1 to 3, characterized in net that as an aliphatic amine ethylenediamine, hexa methylenediamine, isophoronediamine or diethylenetriamine, either which is used alone or in a mixture. 5. The method according to claims 1 to 4, characterized in net that as ketone acetone, methyl ethyl ketone or Mixtures of them. 6. The method according to claims 1 to 5, characterized in net that the mixture (M) is prepared by the ketone or the aldehyde and the amine in the absence of other auxiliary or solvent mixed at 10 to 100 ° C. 7. The method according to claims 1 to 6, characterized in net that the molar ratio of the primary and secondary Amino groups as the starting compounds for the preparation of Mixture (M) amines used to the isocyanate groups of prepolymers produced in step I 10: 1 to 0.1: 1 is. 8. The method according to claims 1 to 7, characterized in net that the molar ratio of the isocyanate groups in Step I made polyurethane prepolymers to the primary ren and secondary amino groups of the amines, which for the manufacture tion of the mixture (M) are used, 5: 1 to 1.01: 1 is and during or after the dispersion at least one amine, the at least 2 amino groups  chooses from the group of primary and secondary amino groups pen, carries, clogs (step IV). 9. The method according to claim 8, characterized in that the molar ratio of the primary and secondary amino groups the amines used to prepare the mixture (M) become the primary and secondary amino groups of the amine, that is used in step IV, 0.01: 1 to 2: 1 be wearing. 10. The method according to claims 1 to 9, characterized in net that as monomers a) at least 50 mol% hexamethylene uses diisocyanate. 11. Aqueous dispersion containing a polyurethane polyurine fabric available according to claims 1 to 10. 12. Use of the dispersions according to claim 10 as coating agent or adhesive.