DE2730514A1 - PROCESS FOR THE PRODUCTION OF WATER-SOLUBLE POLYURETHANES - Google Patents

Description

Process for the production of water-soluble polyurethanes

Aqueous solutions of polyurethanes or polyurethane ureas have long been known (see e.g. Angewandte Chemie, 82, (1970) pages 53 to 55, there reference cit. 4-8, 10a).

The hydrophilic centers built into the known, water-soluble polyurethanes or polyurethane ureas can represent both salt-like, i.e. ionic groups and hydrophilic non-ionic groups.

The first-mentioned "polyurethane ionomers" include both chemically fixed cations, i.e. in particular chemically incorporated cations Polyurethanes containing ammonium ions as well as chemically fixed anions, i.e. in particular chemically built-in anions Polyurethanes containing sulfonate or carboxylate groups. The latter are nonionic, soluble in water Polyurethanes include, in particular, the polyurethanes or polyurethane ureas containing polyethylene oxide chains.

The solutions of these polyurethanes have different, characteristic sets of properties depending on the type of hydrophilic center. So are polyurethane ionomer solutions because the

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contained in them salt groups are in their solubility practically not dependent on temperature, to heating to boiling stable, non-ionic solutions, however, coagulate on heating (at about 60 ⁰ C), as the polyethylene oxide chain at a higher temperature gradually lose their solubility in water. In contrast to ionomers, however, these solutions are resistant to the addition of practically unlimited amounts of electrolytes and are also stable after freezing and thawing.

The sensitivity to electrolytes is with solutions cationic polyurethanes are particularly large, but solutions of polyurethane polycarboxylates are also sensitive. Low Quantities of aqueous electrolyte solutions cause turbidity, larger quantities lead to slimy or cheesy deposits. Even if flocculation does not occur, the colloid chemical state changes, which for example noticeable in changed viscosity and rheology.

This electrolyte instability is extremely disadvantageous in many cases and makes it difficult or even inhibits the practical use of the products. For example, the use of polyurethane ionomer solutions for the production of Pigment pastes for the surface coating of inorganic Substrates such as fillers and fibers, as dyeing auxiliaries, have a certain resistance to electrolytes necessary.

The present invention now provides new water-soluble polyurethanes available in the form

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their aqueous solution both the advantage of excellent prostate and electrolyte resistance and the advantage have a very good temperature resistance. As was surprisingly found, the production succeeds such water-soluble polyurethanes if both ethylene oxide units are present in the polyurethane hydrophilic segments as well as ionic groups are incorporated. This is quite surprising, since it turned out that mixtures of aqueous solutions of ionic and nonionic polyurethanes are by no means such Have a combination of desirable properties. Rather, such mixtures primarily have the disadvantages of the individual components.

By incorporating hydrophilic polyether segments, either within the main polymer chain or at its ends or Polyurethanes also provide surprisingly effective protection in the form of pendant chains

¹ + + θ
-N-, -S- or COO groups

I I

have achieved against the action of electrolytes. Even with a high content of cationic centers, e.g. more than 20 milliequivalents per 100 g of polyurethane

1+ +

-N- or -S- groups

I I

the solutions are no longer precipitated by dilute sodium chloride solution.

The present invention thus relates to electrolyte-stable ones aqueous solutions of polyurethane ionomers with an essentially linear molecular structure, characterized by

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a) hydrophilic polyalkylene oxide polyether chains with an ethylene oxide unit content of 2 to 50% by weight, based on the entire polyurethane and

β) + θ

b) a content of = N =, -S- or -COO groups from 16 to

■
250 milliequivalents per 100 grams.

Finally, the present invention also relates to the preferred process for the preparation of those according to the invention Polyurethanes which are soluble in water and have an essentially linear molecular structure through the conversion of organic Diisocyanates with terminal isocyanate groups which are difunctional in the sense of the isocyanate polyaddition reaction organic reactive hydrogen atoms Compounds with a molecular weight range from 300 to 600O using the solubility of the polyurethanes ensuring structural components with hydrophilic groups or groups which can be converted into such hydrophilic groups, the at least partial conversion of the latter Groups in hydrophilic groups takes place during or after the polyaddition reaction, and optionally using the chain extenders known per se in polyurethane chemistry, one below 300 Molecular weight and, if appropriate, using the auxiliaries customary in polyurethane chemistry Additives, characterized in that as structural components with hydrophilic groups or with in hydrophilic Groups convertible groups both

a) Mono- or diisocyanates and / or in terms of the isocyanate polyaddition reaction mono- or difunctional compounds with isocyanate-reactive groups

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Having hydrogen atoms with ethylene oxide units hydrophilic chains as well

b) mono- or diisocyanates and / or in the sense of the isocyanate polyaddition reaction mono- or difunctional compounds with isocyanate-reactive groups Hydrogen atoms with ionic groups or groups which can be converted into ionic groups

be used, whereby the type and amount or neutralization or the degree of quaternization of components a) and b) is such that in the polyurethane ultimately obtained 2 to 50% by weight of ethylene oxide units and 16 to 250 milliequivalents per 100 g of ionic groups are present.

Organic suitable for the preferred, abovementioned process for the preparation of the polyurethane elastomers according to the invention Diisocyanates are those of the general formula R (NCO) 2 »where R stands for an organic radical like him by removing the isocyanate groups from an organic diisocyanate of the molecular weight range 112-1000, preferably 140-400. Particularly preferred diisocyanates suitable for the process according to the invention are those of the general formula given, in which R is a divalent aliphatic hydrocarbon radical with 4-18 carbon atoms, a divalent cycloaliphatic Hydrocarbon radical with 5-15 carbon atoms, a divalent aromatic hydrocarbon radical with 6-15 carbon atoms or an araliphatic hydrocarbon radical with 7-15 carbon atoms. Typical Representatives of organic diisocyanates which are preferred for the process according to the invention are e.g. Tetramethylene diisocyanate, hexamethylene diisocyanate, dodeca-

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methylene diisocyanate, cyclohexane-1,3- and 1,4-diisocyanate, 1-isocyanato-S-isocyanatomethyl-S, 5,5-trimethylcyclohexane, 4,4'-Diisocyanatodicyclohexylmethane or aromatic ones Diisocyanates, such as 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, Mixtures consisting of these isomers, 4,4'-diisocyanatodiphenylmethane, 1,5-diisocyanatonaphthalene, etc.

Suitable for the process according to the invention, in the sense of Isocyanate polyaddition compounds having difunctional terminal compounds which are reactive toward isocyanate of the molecular weight range 300-6000, preferably 500-3000, are in particular

1. the dihydroxy polyesters known per se in polyurethane chemistry from dicarboxylic acids, such as succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, Isophthalic acid, terephthalic acid, tetrahydrophthalic acid, etc. and diols such as ethylene glycol, propylene glycol-1,2, 1,3-propylene glycol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol, 2-methypropanediol-1,3, or the various isomers Bishydroxymethylcyclohexane;

2. the polylactones known per se in polyurethane chemistry, such as those based on the divalent ones mentioned above Alcohol-initiated polymers of f-caprolactone;

3. The polycarbonates known per se in polyurethane chemistry, such as those obtained by reacting, for example, the above-mentioned diols with diaryl carbonates or phosgene are accessible;

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4. the polyethers known per se in polyurethane chemistry, such as those using divalent starter molecules such as water, the above-mentioned diols or polymers or copolymers of styrene oxide produced by amines containing 2 N-H bonds, Propylene oxide, tetrahydrofuran, butylene oxide or epichlorohydrins; Ethylene oxide can also be used proportionally with the proviso that the polyether used is a maximum of about 10 percent by weight of ethylene oxide contains. In general, however, those polyethers are used without. Use of ethylene oxide were obtained;

5. the polyethioethers known per se in polyurethane chemistry, Polythio mixed ethers, polythioether esters *,

6. The polyacetals known per se in polyurethane chemistry, for example from the diols mentioned above and formaldehyde; as

7. Bifunctional terminal polyether esters which are reactive toward isocyanate groups.

In the process according to the invention, preference is given to dihydroxy polyesters, Dihydroxypolylactones, dihydroxypolyethers and dihydroxypolycarbonates are used.

In principle, however, the compounds according to the invention could even without the use of higher molecular weight polyhydroxy compounds, i.e. exclusively with use of diisocyanates and low molecular weight reactants (molecular weight -c300).

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As in the process of the invention for producing the chain extenders with a molecular weight below 300 to be used for water-soluble polyurethanes for example the low molecular weight diols described in the production of the dihydroxy polyesters or else Diamines, such as diaminoethane, 1,6-diaminohexane, piperazine, 2,5-dimethylpiperazine, 1-amino-3-aminomethy1-3,5,5-trimethylcyclohexane, 4,4'-diaminodicyclohexylmethane, 1,4-diaminocyclohexane, 1,2-propylenediamine or hydrazine, amino acid hydrazides, hydrazides of semicarbazidocarboxylic acids, Bis-hydrazide and bis-semicarbazide can be considered.

Suitable components are also e.g. oleyl diethanolamine, Stearyl diethanolamine, adducts of long-chain alkyl isocyanates of diethanolamine or other amino alcohols, esterification products of long-chain fatty acids with glycerine or trimethylolpropane, adducts of 6-24 carbon atoms or amines or phenols with glycide or 3-ethyl-3-hydroxymethyl-oxetane.

In addition to the above-mentioned structural components which are difunctional in the sense of the isocyanate polyaddition reaction, special Cases in which a low degree of branching of the polyurethanes is desired, including those in polyurethane chemistry Trifunctional and higher-functional structural components known per se can also be used in small proportions. However, the starting components are preferably chosen so that the functionality is not on average 2.1 exceeds.

In the method according to the invention:

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a) Any mono- or diisocyanates and / or mono- or difunctional in the sense of the isocyanate polyaddition reaction Compounds with isocyanate groups reactive hydrogen atoms with ethylene oxide units having hydrophilic chains and

b) any mono- or diisocyanates and / or mono- or difunctional in the sense of the isocyanate polyaddition reaction Compounds with opposite isocyanate groups reactive hydrogen atoms with ionic groups or groups which can be converted into ionic groups can also be used.

The preferred hydrophilic structural components with lateral ethylene oxide units having hydrophilic ones Chains belong to both compounds of the formula

R ¹ R ¹

ι ι

HO-CH-CH ₂ -N-CH ₂ -Ch-OH (I) CO-NH-R-NH-CO-O-X-Y-R "

and / or compounds of the formula

OCN-R-N-CO-NH-R-NCO (II)

CO

Z-X-Y-R "

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Particularly preferred structural components a) are those of the first-mentioned formula (I).

In the above formulas (I) and (II) stand

R for a divalent radical, as obtained by removing the isocyanate groups from a diisocyanate of the formula R (NCO) _{2 of} the type mentioned above,

R ^{1 represents} hydrogen or a monovalent hydrocarbon radical having 1 to 8 carbon atoms, preferably for
Hydrogen or a methyl group,

R "for a monovalent hydrocarbon radical with 1 to Carbon atoms, preferably an unsubstituted alkyl radical with 1 to 4 carbon atoms,

X for the remainder as obtained by removing the terminal one
Oxygen atom from a polyalkylene oxide chain with 5
to 90, preferably 20 to 70 chain links is obtained, which chain links consist of at least 40%, preferably at least 65% of ethylene oxide units and which, in addition to ethylene oxide units, can also represent propylene oxide, butylene oxide or styrene oxide units, with the the latter units propylene oxide units are preferred,

in

Y for oxygen or -NR -, where R ^m with respect to its

Definition R "corresponds,
Z stands for a residue that corresponds to the definition of Y in its meaning.

The compounds of the abovementioned formulas (I) and (II) can be prepared according to the procedures of the DT-OS
314 512 or 2 314 513, with the addition of the

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It is pointed out that the disclosure made there that instead of the polyether alcohols mentioned there as starting material it is also possible to use those whose polyether segment, in addition to ethylene oxide units, also has up to 60 % By weight, based on the polyether segment, of propylene oxide, butylene oxide or styrene oxide, preferably propylene oxide, units exhibit. The proportion of such "mixed poly ether segments" can have specific advantages in special cases le bring with them.

Dihydroxypolyethers also containing ethylene oxide units of the molecular weight range 300-6000, preferably 500-3000, can be used as a hydrophilic structural component in the invention Process can also be used. Also hydrophilic ether groups, i.e. containing polyethylene oxide units Dihydroxy polycarbonates are suitable as hydrophilic structural components.

Further particularly preferred hydrophilic structural components for incorporating terminal or lateral hydrophilic components Chains containing ethylene oxide units are compounds of the formula

HO-XYR "or HR ¹ NXYR"

and / or compounds of the formula

OCN-R-N-CO-Z-X-Y-R "

X, Y, Z, R, R "have the meaning explained above.

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Structural components b) essential to the invention are, for example in the sense of the isocyanate polyaddition reaction, monofunctional or difunctional representatives of the in US Pat. No. 3,479,310, Column 4, line 11 to column 5, line 46, by way of example compounds mentioned or the corresponding compounds accessible by simple neutralization or quaternization with salty groups. Suitable neutralizing or quaternizing agents are, for example compounds mentioned in column 6, lines 14 to 39 of said US patent.

For the incorporation of tertiary sulfonium groups into the polyurethane Examples include those listed in US Pat. No. 3,419,533, column 3, line 75 to column 4, line 51 Connections used as structural components.

In principle, it does not matter in which way the cationic ones Centers built into the polyurethane. For example, in addition to the two patent specifications mentioned Methods listed also produce a polyurethane or NCO prepolymer bearing epoxy groups and by reaction of the epoxy group with a primary or secondary amine introduce the basic center, which is then replaced by a inorganic or organic acid or an alkylating agent is converted into the salt form.

In the method according to the invention, the type and amount of the components a) chosen so that in the polyurethanes according to the invention 2 to 50, preferably 11 to 20 wt .-% in the Ethersegments built-in ethylene oxide units -CH - CH - O- are present. The type and amount or the neutralization or

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The degree of quaternization of components b) in the process according to the invention is chosen so that in the polyurethanes according to the invention 16 to 250 milliequivalents per 100 g, preferably 20 to 100 milliequivalents per 100 g of = N® =, -COO ⁹

Φ
or -S - groups are present. Preferably the sum is

the number of milliequivalents of incorporated ionic groups per 100 g of polyurethane and the number of "pseudomilliequivalents" of built-in ethylene oxide units per 100 g of polyurethane at 40 to 300 and particularly preferably between 60 and 200.

Less than a "pseudomilli equivalent" of built-in ethylene oxide units is to be understood here as the amount of ethylene oxide units built into a polyalkylene oxide chain which makes the same contribution to the solubility of the polyurethane in water as a milliequivalent of built-in ionic groups. (The effectiveness of the above ionic groups in terms of their contribution to solubility of the polyurethane depends solely on the number of milliequivalents of ionic groups and not on the type of the ionic groups.) In the case of the aqueous polyurethane solutions, the solubility depends on the concentration of the built-in hydrophilic centers in the polyurethane. As it turned out on the basis of in-depth studies by the applicant, can be used in any water-soluble, exclusively ionically modified polyurethane with otherwise completely analogous molecular structure the ionic groups always by a certain amount of arranged within a polyether chain To replace ethylene oxide that a corresponding exclusively nonionically modified polyurethane obtained which has the same solubility in water, (with an analogous method of preparation of the polyurethane solutions

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is assumed) if the ionically modified polyurethane present milliequivalents of ionic groups by the same number of "pseudomilliequivalents" non-ionic groups are replaced. One milliequivalent of built-in ionic groups corresponds to 0.5 g Ethylene oxide units built into a polyether chain. Accordingly, under a "pseudomilli equivalent" of nonionic groups are 0.5 g of within one To understand polyether chain built-in ethylene oxide units. As a result, it has an exclusively ionically modified one Polyurethane with a content of 40 milliequivalents per 100 g of one of the abovementioned ionic groups the same water solubility as an exclusively nonionically modified one which is constructed and produced analogously Polyurethane with a content of 20 g per 100 g of ethylene oxide incorporated within a polyether chain.

Carrying out the process according to the invention for production the water-soluble polyurethanes can both by the methods of polyurethane chemistry known per se be carried out according to the one-step as well as the two-step process (prepolymer process).

In the production of the water-soluble polyurethanes, the reactants come in an equivalent ratio of isocyanate groups to isocyanate-reactive groups of 0.8: 1 to 2.5: 1, preferably 0.95: 1 to 1.5: 1 for use. When using an excess of NCO, this naturally results in compounds containing NCO groups, which, when converted into an aqueous solution, react further with the water to form the end product with chain extension. Accordingly, the above equivalent includes

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ratio all in the structure of the polyurethanes according to the invention participating components including the amino groups optionally used in the form of aqueous solutions Chain extenders, but not the proportion of the water used to dissolve the polyurethanes, which with any compounds containing NCO groups which may be present reacts with a chain-lengthening reaction. in the In the context of the present invention, any carboxyl groups present in the reaction mixture are otherwise (Component b)) is not considered as isocyanate-reactive groups, which in view of the The inertia of these groups towards isocyanate groups justifies.

Both the one-step and the two-step process can be carried out in the presence or absence be worked by solvents. Suitable solvents, especially when, as described below - during or the intention is to convert the polyurethanes into an aqueous solution after the polyurethane has been produced is, for example, are water-miscible, isocyanate-indifferent solvents with a below 100 C boiling point such as acetone or methyl ethyl ketone.

When carrying out the one-step process, preference is given to the difunctional terminal ends mentioned above under 1. to 7. compounds having groups which are reactive toward isocyanate groups and having a molecular weight range of 500 up to 60OO with the hydrophilic chain extenders a) and b) as well as the chain extender to be used if necessary

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a molecular weight below 500. The mixture thus obtained then becomes the diisocyanate component added in the absence of solvents, after which the reaction mixture is preferably at 50 to 150C lying temperatures, optionally after addition of the catalysts known per se in polyurethane chemistry for Reaction is brought. The amount of diisocyanate components is chosen so that there is an NCO / OH ratio of 0.8 to 1.05. The viscosity increases during the reaction of the reaction mixture, so that one of the solvents mentioned is gradually added to the mixture. Finally, an organic solution of the aureacted polyurethane is obtained, the concentration of which is preferably up 10 to 70, in particular 15 to 55, wt .-% solids is set. This one-step process is recommended in particular the use of tertiary amines with 2 alcoholic hydroxyl groups as component b). If as Component b) compounds are used which have groups convertible into ionic groups, recommends this conversion can be achieved by neutralization or quaternization, known per se, following the polyaddition reaction either in organic solution or in such a way that the polyurethane present in organic solution neutralized during its conversion into an aqueous solution by neutralizing agents present in the water will.

The conversion of the polyurethanes into an aqueous solution is expediently carried out by adding water to the stirred solution or melt. After removal by distillation a purely aqueous solution remains of any solvent present.

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When performing the two-step process, preference is given to initially in the melt from excess diisocyanate, higher molecular weight compound with opposite isocyanate groups reactive groups of the above under 1. to 7. exemplified type and hydrophilic chain extender a) and optionally b) while maintaining an NCO / OH ratio from 1.1: 1 to 3.5: 1, preferably 1.2: 1 up to 2.5: 1, in the absence of solvents or even in the presence of solvents, an NCO prepolymer prepared, which in the absence of solvents then, for example in a suitable solvent is recorded. The solution of the prepolymer thus obtained can then be mixed with the chain extender in a manner known per se of the type exemplified above with a molecular weight below 300 reacted will. A special variant of the two-stage process is recommended for the production of the polyurethane solutions according to the invention, in which the solution of the NCO prepolymer described with the solution of the chain extender - here the diamines or hydrazine derivatives mentioned are preferably used as chain extenders - in small amounts Amounts of water or a water / solvent mixture added so that the NCO / NH ratio between 2.5 and 1.05. This reaction can take place at room temperature or, preferably, at 25-60 ° C. By subsequent Addition of the remaining water and subsequent removal of the solvent finally becomes the aqueous Obtained polyurethane solution. In this process variant, however, it is also possible to use the chain extender in the Total amount of water finally present in the solution (50-200% by weight, based on solid polyurethane)

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to solve. When carrying out the two-stage process, it is entirely possible and often also preferred to use the component b) not to be incorporated into the prepolymer, but rather aqueous solutions of diaminocarboxylates in the case of the described Chain extension reaction instead of or in combination with the above-mentioned diamines or hydrazine derivatives to use.

However, the two-stage process described is preferably carried out in a solvent-free manner without major difficulties in such a way that the NCO prepolymer described Manufactures solvent-free and stirred into the water as a melt, the amino groups mentioned here as well having ionic or nonionic chain extenders can be present in dissolved form in water.

Of course, it is also possible, as is customary with solid thermoplastics, to melt the polyurethane from the Build components, e.g. in a mold, on a steel belt or in a screw, to shred the solid product and then to dissolve in water.

The water-soluble polyurethanes of the invention are of predominantly linear molecular structure and are due to a content of built-in within a polyether chain Ethylene oxide from 2 to 50, preferably 11 to 20 wt .-%

Φ θ ffi

and a content of = N =, -COO or -S - groups of

16 to 250, preferably 20 to 100 milliequivalents per 100 g. Preferably the pendent Polyalkylene oxide chain, the ethylene oxide units essential to the invention has over groupings

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i) the formula

-N-CO-NH-R-NH-CO-O-X-Y-R "

or

ii) the formula

-N-CO-Z-X-Y-R "

connected, where

R, R ", R ¹ ", X, Y and Z have the meanings given above.

The variant of the invention described above Process represents only a preferred, but not the only, route to the polyurethanes according to the invention. Another route to the polyurethanes according to the invention consists, for example, in the introduction of the nonionic ones lateral hydrophilic groups in a group which already has ionic groups or which can be converted into ionic groups, preferably linear polyurethane elastomer by reacting this elastomer with hydrophilic monoisocyanates the formula

OCN-R-NH-CO-O-X-Y-R "

in which

R, X, Y, R ″ and R ″ ^{1 have} the meanings given above.

Dio production of such hydrophilic monoisocyanates happens in analogy to the procedure described in DT-OS 2 314 512 but also here in addition to what is made there

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Disclosure it is pointed out that instead of the monofunctional polyether alcohol mentioned there as starting material also those can be used whose polyether segment except Ethylene oxide units also up to 60, preferably up to 35 Gev /.- 'i, based on polyether segment on propylene oxide, butyloxide or Styrene oxide, preferably propylene oxide units.

In the production of the polyurethanes according to the invention under Use of these hydrophilic monoisocyanates is preferably a linear polyurethane from the starting materials mentioned produced using an equivalent ratio of isocyanate groups: isocyanate groups reactive Groups of preferably 1: 1, which ionic groups or /. groups which can be converted into ionic groups, however, are not yet hydrophilic Has polyether segments. This linear polyurethane elastomer is then in the melt or in a suitable Solvent, for example of the type mentioned above, reacted with the hydrophilic monoisocyanates at 50 to 150 ° C., with

in particular an addition of the isocyanate group of the hydrophilic monoisocyanate to the active hydrogen atoms of the urethane and / or urea groups present in the linear polyurethane occurs. Any groups that can be converted into ionic groups are then at least partially converted into the ct. corresponding ionic groups transferred. In this embodiment of the production of the polyurethanes according to the invention, when using structural components containing carboxyl groups, the carboxyl groups of which are then to be converted into carboxylate groups by neutralization, care must be taken that only compounds containing carboxyl groups are used whose carboxyl groups are opposite to isocyanate groups have a lower reactivity towards isocyanate groups than urethane or urea groups.

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Furthermore, a mode of operation is particularly preferred in which a prepolymer with terminal NCO groups is reacted with a monofunctional hydrophilic polyether, so that a polymeric polyurethane with terminal hydrophilic polyether segments is formed. Of course you can
Such a product can also be obtained by a one-step process by using a corresponding hydrophilic monofunctional polyether in the construction of the polyurethane as
Structure component is also used. Finally, of course, you can also use a prepolymer terminated
OH, SH, NH, NHR or COOH groups with a hydrophilic
Monoisocyanate of the formula

OCN-R-NH-CO-O-X-Y-R "

realize. Here, R, X, Y, R ″ have the meaning given above.

This group of polyurethanes according to the invention is through the grouping

-U-R-NH-CO-O-X-Y-R "marked,

U stands for -0-CO-NH-, -NH-CO-NH-, -NH-CO-, -S-CO-NH-

and
R, X, Y, R "have the meaning given above.

If polyurethanes are produced with terminal monofunctional hydrophilic polyethers, care is preferably taken to ensure that these products are at least slightly branched, for example by using a proportion of tri- or
polyfunctional structural components or by partially
Allophanatization, trimerization or biuretization.

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The polyurethane according to the invention thus obtained, which is present as a melt or as a solution, can then be mixed by mixing be converted into an aqueous solution with water and, if appropriate, subsequent distillation of the auxiliary solvent.

The aqueous polyurethane solutions according to the invention are clear and show no Tyndall effect even when diluted to a solids content of e.g. 5-10%. At room temperature Layers that have dried out from the solutions dissolve again smoothly and barely in water.

Despite their relatively high content of ionic groups, the solutions are largely insensitive to electrolytes; this allows, for example, acid-catalyzed crosslinking with formaldehyde or formaldehyde derivatives; so is hers Pigmentation with electrolyte-active pigments or dyes possible. Another property of the invention Dispersions are their compatibility with alum solutions in paper sizing.

The solutions of the polyurethane compounds in water are stable, Can be stored and shipped and can be used at any later point in time, e.g. B. foragebend be processed. They dry generally inevitable to form stable plastic coatings on, however, the shape of the process products also take place in the presence of crosslinking agents known per se. Depending on the chosen chemical composition and the content of urethane groups, polyurethanes with different properties are obtained. So can be soft sticky Cash registers, thermoplastic and rubber-elastic products of the

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various degrees of hardness up to glass-hard thermosets can be obtained. The hydrophilicity of the products can also be fluctuate within certain limits. The elastic products can be used for higher tenperotures, for example 100 - 18o C, Process thermoplastically as long as they are not chemically cross-linked

The process products are to be coated or coated and for impregnating woven and non-woven Textiles, leather, paper, wood, metals, ceramics, jtein, 3eton, bitumen, hard fiber, straw, glass, porcelain, plastics of various types, glass fibers, for antistatic and crease-free finishing, as a binder for fleeces, Adhesives, adhesion promoters, lamination agents, water repellants, Veichaacher, binders, e.g. B. for cork or wood flour. Glass fibers, asbestos, paper-like materials, plastic or Cuaai waste, ceramic materials, as auxiliary materials ic stuff printing and in the paper industry, as an additive to polymers, Suitable as a sizing agent, for example for glass fibers, and for leather finishing.

By using vinyl polymers or active or Inactive fillers, one can deal with the properties of the process products. Can be used, for example Polyethylene, polypropylene, polyvinyl acetate, ethylene-vinyl acetate copolyraerisate, which may be (partially) saponified and / or grafted with vinyl chloride, Styrene-butadiene copolymers, ethylene (graft) copolymers, Polyacrylates, carbon black, silica, asbestos, talc, kaolin, titanium dioxide, gloss as a powder or in the form of fibers, cellulose. Depending on Desired signature image and intended use of the 2nd products can be up to £ 7o, based on total dry matter, such fillers may be included in the final product.

Of course, dyes, fillers, pigments, plasticizers or theological properties can also be used Additives are added, as well as e.g. polymer dispersions, RuIi- and cresolic acid brine.

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The drying of the products obtained by various application techniques can be carried out at room temperature or at elevated temperatures the temperature.

The following examples are intended to explain the composition, production and some physical properties.

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example 1

262 g (0.444 mol) of a polyethylene oxide / polypropylene oxide diol started on propylene glycol with a proportion of polyethylene oxide of 70 wt .-%, OHZ 190 are together with 50 g (0.023 mol) of a nonionic-hydrophilic chain extender, which is carried out in analogy to the procedure described in US Pat. No. 3,905,929 by implementing equivalent parts

i) a polyether monoalcohol made from n-butanol, ethylene oxide and propylene oxide (in a weight ratio of 83:17) with an OH number of 30;

ii) 1,6-hexane diisocyanate and

iii) diethanolamine

is prepared and has an average molecular weight of 2140, dehydrated for 1 hour at 120 ° C and 15 Torr in a water jet pump vacuum. The mixture is allowed to cool to 80.degree. C., 102.3 g of 1,6-hexane diisocyanate are added and the mixture is stirred at 120.degree. C. for 2 hours. The prepolymer obtained has an NCO content of 2.07%, it is diluted with 100 ml of acetone while cooling, then 9.5 g (0.08 mol) of N-methyl diethanolamine are added at 60 ° C. (bath temperature) and 1 Stirred for an hour at an outside temperature of 60 ° C. The mixture is diluted with a further 200 ml of acetone under constant temperature conditions, 1.6 g (0.022 mol) of 1,2-diaminopropane, dissolved in 50 ml of acetone, are added, the mixture is stirred for one hour and then quaternized for one hour with 9.5 g (0.075 mol) Dimethyl sulfate. The ammonium salt formation is achieved by addition of 8 g H ₃ PO ₄ (85%) completed in 50 ml of water was further stirred at 6O ⁰ C external temperature until IR spectroscopy no more NCO can be detected (which, in general, after 1 hour of Case is) and diluted at 50 ⁰ C with 750 ml of water. After distilling off the

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Acetone at 50 C in a water jet pump vacuum remains a cationic polyurethane solution with a solids content of 37.5% by weight, a viscosity of 700 cP at 22 ° C., a pH of 2.4 and based on 100 g of polyurethane 20 milliequivalents of quaternary nitrogen and 100 pseudo milliequivalents of ethylene oxide units. 50 g of this polyurethane solution adjusted to 10% solids can be mixed with 10 g of a 10% saline solution without coagulation occurring (see general instructions for determining the electrolyte stability of ionic PU solutions).

General regulation for determining the electrolyte stability of ionic PU solutions

50 ml of an ionic PU solution adjusted to 10% solids are placed in an Erlenmeyer flask and taken under vigorous stirring with a magnetic stirrer at room temperature drop by drop from a storage burette with 10% aqueous NaCl solution added. As the cloudiness increases, the solution usually coagulates suddenly, at least in one of them Consumption of saline solution <20 ml. With even higher electrolyte stability the determination of the end point sometimes causes difficulties, since the coagulation is only hesitant under partial Flocculation occurs. In this case, the endpoint determination is made easier if the saline solution added in 5 ml portions, stirred for 5 minutes after each addition and then assessed.

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Example 2

177 g (0.300 mol) of a polyether diol started on propylene glycol according to Example 1 and 175 g (0.100 mol) of a polyester diol from adipic acid, Phthalic anhydride and ethylene glycol and 107.5 g (0.050 mol) of the nonionic hydrophilic chain extender according to Example 1 were dehydrated for one hour at 120 ° C., 15 torr, cooled to 80 ° C. and admixed with 109 g (0.650 mol) of hexane diisocyanate. It is left for 2 hours Stir at 120 C, a prepolymer with an NCO content of 2.19% results. It is diluted with 200 ml of acetone while cooling. At a bath temperature of 60 ° C are 11.9 g (0.100 mol) of N-methyl diethanolamine added and stirred at 60 ° C. for 60 minutes. At the same temperature, 3.6 g (0.050 mol) of 2-diaminopropane are added, along with a further 200 ml of acetone diluted for 60 min. Stirred and then quaternized with 11.9 g (0.094 mol) of dimethyl sulfate. An hour later you will be able to remove it in the IR spectrum NCO groups still detectable 80 g of water are added and diluted with a total of a further 1200 ml of acetone and the NCO-free after 3 hours acetone polyurethane solution mixed with 8 g of phosphoric acid (85%). At 50 ° C., the mixture is diluted with 1.4 l of water preheated to 50 ° C. and the acetone is distilled off in a water jet pump vacuum. A cationic, aqueous polyurethane solution is obtained has a viscosity of 4500 cP and a solids content of 20.5% and a pH of 2.3. 50 ml of the to 10% solids The adjusted solution can be mixed with 25 ml of a 10% saline solution be mixed before the first visible precipitation occurs.

1) Based on 100 g of solid, the solution contains 17 milliequivalents N, as well as 68 pseudo-milliequivalent ethylene oxide units.

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Example 3 (comparative example)

As a comparative example to Example 2, a similar polyurethane solution without hydrophilic ethylene oxide units was prepared, the proportion of quaternary nitrogen being increased so that it corresponded to the sum of milliequivalents of quaternary nitrogen and pseudomilli-equivalent of ethylene oxide according to Example 2.
Composition:
175 g (0.100 mol) of a polyester diol according to Example 2, 84 g (0.500 mol) hexane diisocyanate-1,6

34 grams (0.285 moles) of N-methyl diethanolamine 5.7 g (0.078 moles) of 1,2-diaminopropane

34 g (0.270 moles) dimethyl sulfate

8 g o-phosphoric acid (85%)
800 ml water (preheated to 50 ° C)

The aqueous polyurethane solution was prepared according to the example The resulting cationic polyurethane solution has a solid content of 31% by weight, a viscosity of 600 cP at 22 ° C. and a pH value from 1, 8 up. Based on 100 g of solid, the solution contains 85 milliequivalents of quaternary nitrogen. 50 ml of the adjusted to 10% solids Solutions coagulate even if less than 1 ml of a 10% saline solution is added.

Example 4

133 g (0.074 mol) of a polyester diol made from adipic acid and tetraethylene glycol with an average molecular weight of 1,800 and 125 g (0.058 mol) of the nonionic hydrophilic chain

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extender according to Example 1 are drained for 30 minutes at 15 ° C and 120 Rorr, cooled to 80 ⁰ C and 61.3 g of hexane diisocyanate -1. 6 added. After stirring for 2 hours at 120 C 35 wt obtain a prepolymer having an NCO content of 5, -. ⁰ Jo. While cooling, it is diluted with 100 ml of acetone, at 60 C (bath temperature) 23.8 g (0.200 mol) of N-methyldiethanolamine diluted with 50 ml of acetone are added, stirred for one hour at 60 ° C, 0.25 g (0.003 mol) 1,2-Diaminopropane was added and quaternized one hour later at the same temperature with 23.8 g (0.189 mol) of dimethyl sulfate. 30 minutes after the addition of dimethyl sulfate, 20 ml of water are added, and the mixture is then stirred at a bath temperature of 60 ° C. until NCO can no longer be detected by IR spectroscopy. 6 g of 85% phosphoric acid and then 900 ml of water are added and the acetone is removed at 50 ° C. in a water jet vacuum. The resulting aqueous polyurethane solution has a solids content of 30 wt -. "J" having a viscosity of 67 cP at 22 ° C and a pH value of 2, 3 to 100 g of solids containing 53 milliequivalents of the quaternary nitrogen and 50 pseudo milliequivalents of ethylene oxide. 50 ml of a sample of this solution adjusted to 10% solids tolerate the addition of 100 ml of a 10% saline solution without coagulation occurring.

Example 5:

230 g of a technical polyethylene glycol mixture with a medium Molecular weight of 230 (as it is obtained as a residue from the distillation of tetraethylene glycol) and 119 g of N-methyldiethanolamine are mixed ».-

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mixed together and in the stirred mixture at 80 C 262 g of a technical polyisocyanate mixture, as it is as a distillation residue incurred in the production of hexane diisocyanate-1, 6 (NCO content approx. 32% by weight) was slowly added dropwise. 30 minutes after the end of the dropwise addition, NCO can no longer be detected by IR spectroscopy. 173 g of phosphoric acid (85%) and 1769 g of water are then added simultaneously with cooling. The resulting low viscosity polyurethane solution With a solids content of 30% by weight, it has a pH of 1, 6. 50 ml of a sample of this dispersion adjusted to 10% solids tolerate 100 ml of a 10% saline solution without coagulation.

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Claims (2)

Claims 1) Electrolyte-stable aqueous solutions of polyurethane ionomers with an essentially linear molecular structure, characterized by a) hydrophilic polyalkylene oxide polyether chains with a content of bound ethylene oxide units from 2 to 50 wt .-%, based on the total polyurethane, and (B QQ b) a content of = N =, -S- or -COO groups of 16 to 250 milliequivalents per 100 g. 2) Process for the preparation of water-soluble polyurethanes with an essentially linear molecular structure through the reaction of organic diisocyanates with in the sense the isocyanate polyaddition reaction has bifunctional terminal hydrogen atoms which are reactive toward isocyanate groups containing organic compounds of the molecular weight range 300 to 6000 with the inclusion of the structural components with or in such hydrophilic groups ensuring the solubility of the polyurethanes groups convertible to hydrophilic groups, the at least partial conversion of the latter groups takes place in hydrophilic groups during or after the polyaddition reaction, and optionally under Concomitant use of the chain extenders known per se in polyurethane chemistry, one below 300 Molecular weight and, if appropriate, using the auxiliaries and additives customary in polyurethane chemistry Additives, characterized in that as structural components with hydrophilic groups or with in hydrophilic Groups convertible groups both Le A 18 233 - 31 - 809883/0361 ORIGINAL INSPECTED 77105 i a) Mono- or diisocyanates and / or in terms of the isocyanate polyaddition reaction mono- or difunctional compounds with isocyanate-reactive groups Hydrogen atoms with ethylene oxide units containing hydrophilic chains as well b) mono- or diisocyanates and / or in the sense of the isocyanate polyaddition reaction mono- or difunctional compounds with isocyanate-reactive groups Hydrogen atoms with ionic groups or groups which can be converted into ionic groups be used, whereby the type and amount or neutralization or the degree of quaternization of components a) and b) is such that in the polyurethane ultimately obtained 2 to 50% by weight of incorporated ethylene oxide units and 16 to 250 milliequivalents per 100 g of ionic groups are present. Le A 18 233 - 32 - B09883 / 036 1