CA2148550A1

CA2148550A1 - Hydrophilic polyurethane-polyureas and their use as dispersants for synthetic resins

Info

Publication number: CA2148550A1
Application number: CA002148550A
Authority: CA
Inventors: Gerhard Merten; Joachim Zoeller; Edmund Urbano
Original assignee: Individual
Current assignee: Hoechst AG
Priority date: 1994-05-09
Filing date: 1995-05-03
Publication date: 1995-11-10
Also published as: CZ118595A3; EP0682049A1; DE4416336A1; KR950032358A; BR9501946A; JPH0848743A; AU1792295A; ZA953669B

Abstract

Hydrophilic polyurethane-polyureas which are useful as dispersants for synthetic resins obtained by reacting:
(A) a polyisocyanate component comprising at least one organic polyisocyanate, (B) at least one isocyanate-reactive fatty acid derivative, (C) if desired, a compound containing more than two functional groups selected from hydroxyl and carboxyl groups, (D) a polyalkylene glycol component having a molecular mass from 500 to 10,000 g/mol, and (E) a compound having at least one active hydrogen atom which reacts faster than water with NCO groups, while maintaining a molar ratio of isocyanate groups to the sum of hydrogen atoms of the isocyanate-reactive groups, such as the hydroxyl and amino groups, based on all of the starting components (A) to (E), of from 0.5:1 to 2:1.

Description

21~8550 HYDROPHILIC POLYURETHANE-POLYUREAS AND THEIR USE AS
DISPERSANTS FOR SY~.~nh-~lC RESINS

Background of the Invention Field of the Invention The present invention relates to hydrophilic polyurethane-polyureas and to their use, for example, as emulsifiers in aqueous dispersions of hydrophobic synthetic resins.

Description of Related Art The range of water-dilutable binder systems is at present still incomplete, so that at present the replacement of all conventional coating compositions with water-based systems is still not possible. In particular, the air-drying alkyd resins, which are generally employed in the form of solutions in aliphatic or aromatic hydrocarbons, still cannot be replaced by fully equivalent water-based compositions. Films of aqueous dispersions of polymers, based, for example, on polyvinyl acetate, polyolefins, or polyacrylates, fall well short of the quality standard of conventional alkyd resins both in their visual impression (evenness, gloss) and in their protective effect (water resistance, weather resistance).
Water-soluble alkyd resins for air-drying coating materials have also so far failed to become established.
Part of the reason for this is that the average molecular mass of the resins has to be lowered to achieve water-solubility, which unavoidably retards the drying.
Moreover, despite their low molecular mass, these resins require relatively large quantities of auxiliary solvents (for example, glycol ethers, which are also toxic solvents) and organic amines.

~ ~14~$~0 In contrast to these water-soluble resins, aqueous dispersions of synthetic resins, especially alkyd resins should enable an ideal solution to the problem, since in this case it is generally possible to do away with s organic solvents. Also the drying properties would be expected to match those of the conventionally dissolved resins, since it is unnecessary to limit the molecular mass as for the water-soluble resins. Despite this, synthetic resin dispersions of this kind have likewise not hitherto acquired any great significance. The reason is that to date there has not been a successful solution to the problem of stabilizing the dispersions without adversely affecting the other properties.
Synthetic resins, especially alkyd resins, are predominantly hydrophobic substances which do not per se form stable dispersions in water. It is therefore necessary to add emulsifiers. Emulsifiers are generally substances having an amphipathic molecular structure, i.e., they are composed of a hydrophobic and a hydro-philic moiety. As a result of this structure the emulsifier molecules accumulate at the water/resin interface, reduce the interfacial tension, and thus enable the formation of very fine resin droplets in the aqueous phase.
The synthesis of high molecular weight polyurethane-polyureas by chain extension in the aqueous phase is known and is described generally, for example, in DE-A 26 24 442 and in EP-A 0 089 497. The suitability of specific polyurethane-polyureas as emulsifiers, however, was not known.
For synthetic resin dispersions, the best results achieved up to now have been with nonionic emulsifiers formed by condensation of ethylene oxide with octyl- or nonylphenol, i.e., in which the hydrophobic moiety is composed of the alkylphenol radical and the hydrophilic moiety is composed of the polyethylene glycol chain.
Systems of this kind are described in U.S. Patents 3,223,658, 3,269,967, and 3,440,193 and in DD Patent 88 883 and DE-A 27 54 091. Emulsifiers of this kind, ~148550 _ -3-added in quantities of from 5 to 10%, give synthetic-resin dispersions of serviceable stability. The disadvantage is that these emulsifiers remain unchanged in the film and thus bring about a significant reduction in the water resistance. The scope for application of such dispersions is therefore very restricted.
DE-A 39 00 257 describes nonionically hydrophilic polyurethanes which have (meth)acryloyl groups and their use as reactive emulsifiers for urethane (meth)acrylates which are not dispersible in water. With these emulsifiers, however, only a limited number of synthetic resins can be emulsified. For instance, owing apparently to their deficient compatibility, they are unable to emulsify styrene-free unsaturated polyester resins or alkyd resins.
DE-A 40 04 641 describes air-drying polyurethane resins which contain both polyols and monoalcohols having polyunsaturated groups. Up to 40% of conventional alkyd resins can be incorporated into these resins by emulsification. German Patents DE 27 54 141, DE
27 54 092 and DE 24 40 946 describe alkyd resin dispersions which are stabilized in the aqueous phase using emulsifiers which comprise polyethylene glycols, fatty acids, andtor allyl ethers.
Olefinically unsaturated polyurethanes comprising a ~,~-ethylenically unsaturated ether alcohol component are described in EP-A 0 501 247, as is their use as reactive emulsifiers. They are predominantly employed as emulsifiers for unsaturated polyester resins, and are unsuitable for alkyd resins. Owing to their double bonds, these emulsifiers can be incorporated into the film during oxidative drying, thereby improving the water resistance. The low molecular mass of these emulsifiers, however, permits limited migration of the emulsifiers in the film, as a result of which the properties of the resulting film suffer.
A further problem of these alkyd resin emulsions, in addition to slow drying, is their poor pigmentability, since it is generally not impossible with the above-`~ _4_ 21~85~
described emulsions to obtain glossy, highly pigmented films.

SummarY of the Invention An object of the invention was therefore to develop emulsifiers which are able to stabilize hydrophobic synthetic resins in the form of dispersions in water and which do not adversely affect the properties of the films formed after drying, especially with respect to gloss, drying, weather resistance and water resistance.
Another object of the present invention was to provide aqueous synthetic-resin dispersions having storage stability, pigmentability and drying properties which are improved in relation to the known prior art.
These objects have been achieved by the provision of the hydrophilic polyurethane-polyureas of the invention and by their use according to the invention.
In particular, in accordance with the present invention, there are provided hydrophilic polyurethane-polyureas which are obtained by reacting:
(A) a polyisocyanate component comprising at least one organic polyisocyanate, (B) at least one isocyanate-reactive fatty acid derivative, (C) optionally, a compound other than (B), (D) and (E), containing more than two functional groups selected from hydroxyl and carboxyl groups, (D) a polyalkylene glycol component having a molecular mass in the range from 500 to 10,000 g/mol, and (E) a compound having at least one active hydrogen atom which reacts faster than water with NCO groups, while maintaining a molar ratio of isocyanate groups to the sum of hydrogen atoms of the isocyanate-reactive groups, (such as hydroxyl and amino) based on all of the starting components (A) to (E), of from 0.5:1 to 2:1, preferably from 0.7:1 to 1.5:1.
In accordance with another aspect of the invention, there has been provided an aqueous dispersion comprising 214855~
_ -5-a hydrophobic synthetic resin and a hydrophilic polyurethane-polyurea as described above as an emulsifier.
In accordance with the invention, there has also been provided a coating composition comprising the poly-urethane-polyurea and a substrate coated therewith.
Further objects, features, and advantages of the invention will become apparent from the detailed description of preferred embodiments that follows.

Detailed Description of Preferred Embodiments The present invention provides aqueous dispersions of polyurethane-polyureas that are useful as reactive emulsifiers for synthetic resins which are otherwise not dispersible in water, and aqueous dispersions that contain synthetic resins that are otherwise not dispersible in water.
The synthetic resins employed include any desired resins or mixtures thereof, and are preferably any commercial alkyd resin grades. The alkyd resins may be modified slightly in order to increase stability on storage.
The resin dispersion may be prepared in any desired manner. In general, for the preparation of the dispersions, the resins are generally employed in the solvent-free state, although relatively small quantities of solvent may also be added. The amount of solvent must not exceed 10 % of the mass of the resin, preferably less than 5 % is used, most preferred less than 2 %.
To increase its storage stability, the alkyd resin can be modified such that its acid number is as low as possible. This modification can either be carried out during the preparation of the alkyd resin, by esterifi-cation with further alcohols, or else the acid groups can be esterified subsequently using an epoxide. Suitable epoxides include all monoepoxides, which are described, for example, in the handbook "Epoxidverbindungen und Epoxidharze" [Epoxide compounds and epoxy resins] by 21485S~

A.M. Paquin, Springer Verlag, Berlin 1958, chapter IV, and in Lee Neville "Handbook of Epoxy Resins", 1967, chapter 2. Particularly suitable are epoxidized fatty acids and Cardura~ E10 (Versatic acid glycidyl ester from Shell Chemie). However, it is possible to use any type of alkyd resin, either alone or in combination with other resins which are to be dispersed. Also, resins other than alkyd resin can also be dispersed in water by use of the emulsifier of the present invention.
The polyurethane-polyureas according to the invention can be prepared by reacting the starting components (A) to (E) mentioned above in proportions suitable to give a polyurethane-polymer resin.
Preferably from 0.1 to 1 mol of component (B), from 0 to 0.8 mol of component (C), from 0.1 to 0.8 mol of component (D) and from 0.01 to 0.3 mol of component (E) are employed per mole of component (A). It is particularly preferred to employ from 0.2 to 0.6 mol of component (B), from 0 to 0.6 mol of component (C), from 0.2 to 0.6 mol of component (D), and from 0.02 to 0.25 mol of component (E) per mole of component (A).
Component (A) comprises at least one organic polyisocyanate. Any desired polyisocyanates, include resins including isocyanate groups, or mixtures of polyisocyanate can be used. Suitable polyisocyanates for the invention include aliphatic, cycloaliphatic, and/or aromatic polyisocyanates containing at least two isocyanate groups per molecule and having a molecular mass of from 168 to 1,000 g/mol, preferably from 168 to 300 g/mol. Preference is given to compounds having from two to four isocyanate groups per molecule, and particular preference to those having two or three isocyanate groups per molecule. Mixtures of different polyisocyanates can also be used, in which case it is also possible to mix polyisocyanates of different functionalities. It is preferred to use diisocyanates which may contain up to 20 mol % of higher-functional isocyanates as a further constituent of the mixture.

21485~0 _ 7 Suitable aromatic polyisocyanates include the isomers or isomer mixtures of phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, biphenylene diisocyanate, naphthylene diisocyanate and diphenyl-methane diisocyanate, and biphenyl tetraisocyanate,preferably naphthyl tetraisocyanate, tolylene diiso-cyanate, and xylylene diisocyanate.
Examples of useful cycloaliphatic polyisocyanates include isophorone diisocyanate (l-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, "IPDI"), cyclo-pentylene diisocyanate, and the hydrogenation products of aromatic diisocyanates, such as cyclohexylene diiso-cyanate, methylcyclohexylene diisocyanate, and dicyclo-hexylmethane diisocyanate.
Examples of aliphatic polyisocyanates are diisocyanates of the formula O = C = N - (CR2)r - N = C = O

in which r is an integer from 2 to 20, in particular from 6 to 8, and R is hydrogen or a lower alkyl radical having from 1 to 8 carbon atoms, preferably 1 or 2 carbon atoms.
Examples of these include trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, propylene diisocyanate, ethylethylene diisocyanate, dimethylethylene diisocyanate, methyltrimethylene diisocyanate, and trimethylhexane diisocyanate.
Particular preference is given to diphenylmethane diisocyanate and tolylene diisocyanate and to the isomer mixtures thereof, and to isophorone diisocyanate, dicyclohexylmethane diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, and hexamethylene diisocyanate. Vinyl polymers which contain isocyanate groups and are formed by copolymerization of, for example, cyanatoethyl (meth)acrylate or dimethyl-isopropylbenzyl isocyanate with alkyl (meth)acrylatesand/or (alkyl)vinylbenzenes can also be used. Mixed aliphatic/aromatic isocyanate compounds are similarly ~14~5~0 _ 8 suitable. One example of a particularly preferred compound is tetramethylxylylene diisocyanate.
Diisocyanates of the type specified later by way of example are preferred as component (A), although polyisocyanates of higher functionality, for example, biuret-, isocyanurate- or urethane-modified polyisocyanates based on the above-mentioned simple diisocyanates are also suitable. These derivatives generally have a molecular mass of up to 1000 g/mol. The preparation of such derivatives is described in, for example, U.S. Patents No. 3,124,605, No. 3,183,112, No.
3,919,218, and No. 4,324,879, each of which is incorporated by reference.
The isocyanate-reactive fatty acid derivative (B) may be any such compound. By "derivative" it is meant that the fatty acid has been modified to contain groups which are reactive with isocyanate groups. Any type of compound so modified can be used. Preferred compounds contain from 10 to 40 carbon atoms, at least one hydroxyl or amino group and, if desired, at least one C=C double bond. The number of isocyanate-reactive functional groups is generally from one to four, preferably one or two. Examples of these fatty acid derivatives include fatty alcohols such as lauryl alcohol, stearyl alcohol, oleyl alcohol, linoleyl alcohol, or linolenyl alcohol.
Ethoxylated fatty alcohols containing from 1 to 30, preferably 1 to 20, and more preferably from 1 to 10, ethylene oxide units can also be employed, for example, GenapolX 0-020 (Hoechst AG).
Further useful compounds are the alcohols which are obtained by reacting an unsaturated acid with an epoxide, such as a monoepoxide, for example, a fatty acid such as linseed oil fatty acid or soy oil fatty acid with an epoxide such as Cardura0 E10 or other epoxides. Partial esters of polyhydroxy compounds, for example, glycerol, trimethylolpropane or pentaerythritol, and partially hydrolyzed fats can also be employed, examples being Ligalub0 40/1 (fatty acid glycerol monoester from 214855~

g P. Graeven Fettchemie). Also suitable are fatty amines such as, for example, Genamin~ (Hoechst AG).
Component (C) is an optional component and is any compound which is of relatively high functionality and contains more than 2, generally from 3 to 8, particularly preferably from 3 to 6, hydroxyl and/or carboxyl groups.
In this context it is possible to use those compounds which contain only hydroxyl groups. Useful examples include trimethylolpropane, trimethylolethane, glycerol, ditrimethylolpropane, pentaerythritol, and dipenta-erythritol. Other suitable compounds contain at least one, preferably from one to three and particularly preferably one or two hydroxyl groups and at least one, preferably from one to three and particularly preferably one or two carboxyl groups. Suitable hydroxycarboxylic acids are, for example, bishydroxyalkane carboxylic acids, dimethylolpropionic acid, glycolic acid, malic acid, tartaric acid, tartronic acid, citric acid, and 2,6-dihydroxybenzoic acid. Compounds containing only hydroxyl groups are also useful. Similarly, mixtures of two or more of these compounds may also be used.
Component (D) comprises one or more polyalkylene glycols, which are preferably linear, having a number-average molecular mass of from 500 to 10,000 g/mol, preferably from 1,000 to 6,000 g/mol. Any such glycols are useful. Preference is given to polyalkylene ether glycols which have a content of ethylene oxide units of at least 80 mol %, preferably up to 100 mol %, of the alkylene oxide units. "Mixed" polyalkylene glycols of this kind are formed, for example, by using mixtures of different alkylene oxides, for example, ethylene oxide and propylene oxide in a molar ratio of from about 8 to 2, for the preparation of the polyether glycols by alkoxylation of appropriate divalent initiator molecules &uch as, for example, water, ethylene glycol, or propylene glycol.
The compounds employed as component (E) are those which are also called "chain extenders" in the art. Any compounds having at least one active hydrogen atom which ~1~855~

reacts faster than water with NC0 is useful. The functional groups of these compounds may be hydroxyl groups, primary and secondary amino groups, and/or mercapto groups. The number of functional groups is at least one, preferably from two to four and particularly preferably two or three. The suitable compounds may carry only one kind of functional group or may carry different functional groups in the same molecule.
Examples include primary and secondary amines, hydrazine, and substituted hydrazines having at least two isocyanate-reactive hydrogen atoms. Particular preference is given to diamines and polyamines, examples being ethylenediamine, butylenediamine, tolylenediamine, isophoronediamine, 3,3'-dichlorobenzidine, triethylene-tetramine, diethylenetriamine, hydrazine, and substituted hydrazines such as dimethylhydrazine. Examples of further suitable chain extenders which carry different functional groups are alkanolamines such as N-aminoethyl-ethanolamine, ethanolamine, and diethanolamine.
Carboxyl-containing amines or hydrazine derivatives, for example, lysine, glutamic acid, and adipic acid mono-hydrazide, may also be used. Similarly, mixtures of such compounds can also be employed.
The hydrophilic polyurethane-polyureas of the invention may be prepared in any desired manner, but are preferably prepared in two steps. First, a hydrophilic isocyanate-functional prepolymer is synthesized which then, after dispersion in water, is reacted with the chain extenders described under (E).
The preparation of the prepolymer by reacting the above-mentioned starting components (A) to (D) may be carried out in bulk or in solvents which are inert toward isocyanate groups, such as ketones, tertiary alcohols, ethers or esters, specific examples being acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, or toluene, or mixtures of such solvents, while maintaining preferred reaction temperatures of from 20 to 200C, in particular from 50 to 150C. In this context, components (B) to (D) can be reacted with component (A) simultaneously or in 2148~5~

steps. In practice, for example, one possible procedure is to introduce components (B) to (D) as initial charge and to react them within the above-mentioned temperature ranges with the isocyanate (A) until the NC0 content has fallen to a specific value, which requires calculation.
This prepolymer is then dispersed in water and reacted with component (E) at temperatures of, for example, from 40 to 100C. After a reaction period of, for example, from 1 to 5 hours and, if desired, after adding ammonia or amines, the aqueous dispersion of the polyurethane-polyurea is obtained.
In this context, in principle, the nature and proportions of the starting components are chosen within the above-mentioned ranges such that the ratio of the number of isocyanate groups to the number of hydrogen atoms in hydroxyl groups and amino groups in components (A) to (D) is from 0.5:1 to 2:1, preferably from 0.7:1 to 1.5:1.
The urethane formation reactions can be catalyzed in a manner known per se, for example, by tin octoate, dibutyltin dilaurate, or tertiary amines. Likewise, the polyurethane can be protected against premature and unwanted polymerization and/or oxidation by addition of appropriate inhibitors and antioxidants, respectively, in quantities of in each case from of, for example, 0.001 to 0.3% based on the mass of the overall mixture.
The hydrophilic polyurethane-polyureas, possibly containing unsaturated groups, which are obtained in this way have a number-average molecular mass Mn (which can be determined by the method of gel permeation chromatography using polystyrene as standard) which can be varied depending on intended use of the polymer, and which is generally from 2,000 to 20,000 g/mol, preferably from 2,000 to 15,000 g/mol. A content by mass of olefinic double bonds (calculated as -C=C-, molecular mass =
24 g/mol) is generally from 0 to 6%, preferably from 1 to 4%, and a content by mass of ethylene oxide units -CH2-CH2-0-, incorporated by way of polyethylene glycol, 21485~0 _ -12-is generally from 20 to 90%, preferably from 30 to 85~, and with particular preference from 40 to 80%.
These hydrophilic polyurethane-polyureas can be used / in any desired number, and are valuable emulsifiers for hydrophobic synthetic resins which are not dispersible by themselves in water. Such synthetic resins have, for example, a number-average molecular mass Mn (determined as above) of from 500 to 10,000 g/mol, preferably from 500 to 5,000 g/mol.
The synthetic resin dispersions may be prepared in any desired manner. For example, to prepare such synthetic-resin dispersions, the synthetic resins are first of all mixed with the above-described polyurethane-polyurea dispersions, if desired in the presence of the inert solvents described above. The mixtures generally contain from 20 to 97 parts by weight, preferably from 40 to 95 parts by weight, of the above-identified hydrophobic synthetic resins as a mixture with from 3 to 80 parts by weight, preferably from 5 to 60 parts by weight, of the above-mentioned, emulsifying, hydrophilic polyurethane-polyureas. It is, however, important to select the nature and proportions of the individual components, within the framework of the statements which have been made, in such a way that the content by mass of ethylene oxide units originating from component (D) in the water-dispersible mixtures is not more than 20%, preferably not more than 15%. The mixtures can be prepared simply by mixing the individual components, if desired in the presence of further solvents such as, for example, hydrocarbons, alcohols, ketones, glycol ethers, or N-methylpyrrolidone.
To prepare the aqueous synthetic-resin dispersions of the invention, the mixtures according to the invention are dispersed in water, either by simply stirring water into the mixture of the synthetic resins with the polyurethane-polyurea dispersions, using conventional dissolvers, or by pouring the mixture into water with vigorous stirring. If desired, it is possible first to add some of the water to the above-described mixture and ~14855~

then to pour this mixture, with stirring, into the remaining quantity of water. In this way it is possible to obtain stable oil-in-water emulsions.
The aqueous dispersions which are obtained in this way are valuable aqueous binders for coating compositions. They can be used as such or in combination with auxiliaries and additives which are known from paint technology, for example, fillers, pigments, solvents, and/or leveling aids, to produce coatings on any desired substrates.
Through the use of the emulsions according to the invention, aqueous dispersions of alkyd resins with an alkyd content of up to 60% by mass can be prepared. A
typical alkyd content is 25 through 55~ .
Examples of suitable substrates include, for example, paper, cardboard packaging, leather, wood, plastics, nonwovens, films, textiles, ceramic materials, mineral materials, glass, metal, coated metal, synthetic leather, and photographic materials such as, for example, paper bearing a photographic layer.
These coating compositions can be applied in any known manner, for example, by spraying, knife coating, rolling, brushing, dipping, or flow coating. After evaporation of the water and of any inert solvents which may have been used in addition, the crosslinking of the coatings can take place, for example, by curing with metal salts of siccative acids and (hydro)peroxides or other siccatives at temperatures between room temperature and 250C.
The present invention is illustrated by the following, non-limiting examples. In the examples below, all quantities should be read as masses and all percentages as contents by mass.

Examples: Preparation of the polyurethane-polyurea disper~ions a I ~f855~

Example E 1 56 g of linseed oil fatty acid and 52 g of Cardura~
E10 (glycidyl esters of neodecanoic acid) (catalyst:
chromium octoate) are reacted at 120C until an acid number of c 1 mg KOH/g is reached (raw material III).
54 g of dimethylolpropionic acid are dissolved at about 80C in 200 g of polyethylene glycol 1000. 100 g of Solvesso0 100 mixture of branched aliphatic hydrocarbons with medium boiling range and the raw material III are added to the solution. Then, after heating to 80C, 98 g of tetramethylxylylene diisocyanate (TMXDI) and 70 g of tolylene diisocyanate are added dropwise at a rate such that the temperature does not exceed 85C (about 30 min).
Once all the isocyanate has been added, the mixture is subsequently stirred at temperature for one hour and then the reaction temperature is raised to 90C. The temperature is maintained until the isocyanate content has fallen to 1.59%. 1400 g of heated, deionized water are then added over the course of 10 minutes with vigorous stirring. This is followed immediately by the rapid dropwise addition (over about 5 min) of 7.5 g of triethylenetetramine dissolved in 75 g of water. After a reaction period of 3 hours at 80C, 5 ml of 25%
strength ammonia solution are added, and then the mixture is cooled. A pasty dispersion is obtained.

Example E 2 14 g of dimethylolpropionic acid are suspended at about 80C in 100 g of polyethylene glycol with a molar mass of 1000 g/mol. 100 g of Solvesso0 100 and 59 g of Genapol0 O-100 (ethoxylated fatty alcohol) are added to the suspension. Then, after heating to 70C, 27 g of tetramethylxylylene diisocyanate (TMXDI) and 35 g of tolylene diisocyanate (TDI) are added dropwise at a rate such that the temperature does not exceed 70C (about 30 min). Once all the isocyanate has been added, stirring is continued at temperature for one hour and then the reaction temperature is raised to 90C. The temperature is maintained until the isocyanate content 214855~
_ -15-has fallen to 1.7%. 500 g of heated, deionized water are then added over the course of 10 minutes with vigorous stirring. This is followed immediately by the rapid dropwise addition (over about 5 min) of 3.75 g of triethylenetetramine dissolved in 37.5 g of water. After a reaction period of 3 hours at 80C, 5 ml of 25%
strength ammonia solution are added and the mixture is cooled. A pasty dispersion is obtained.

Example E 3 59 g of Genapol~ O-100 are mixed with 200 g of polyethylene glycol with a molar mass of 2000 g/mol, and the mixture is heated to 70C. 100 g of SolvessoX 100 are added to the solution. After the mixture has been heated to 70C, 54 g of tetramethylxylylene diisocyanate (TMXDI) are then added dropwise at a rate such that the temperature does not exceed 70C (about 30 min). Once all the TMXDI has been added, stirring is continued at temperature for one hour and then the reaction temperature is raised to 90C. The temperature is maintained until the isocyanate content has fallen to 1.4%. 500 g of heated, deionized water are then added over the course of 10 minutes with vigorous stirring.
This is followed directly by the rapid dropwise addition (over about 5 min) of 3.75 g of triethylenetetramine dissolved in 37~5 g of water. After a reaction time of 3 hours at 80C the mixture is cooled. A pasty dispersion is obtained.

Example E 4 14 g of dimethylolpropionic acid are suspended at about 80C in 100 g of polyethylene glycol with a molar mass of 1000 g/mol. 100 g of Solvesso~ 100 and 59 g of GenapolX O-100 (ethoxylated fatty alcohol) are added to the suspension. The mixture is heated to 70C and then 27 g of tetramethylxylylene diisocyanate (TMXDI) and 35 g of tolylene diisocyanate (TDI) are added dropwise at a rate such that the temperature does not exceed 70C
(about 30 min). Once all the isocyanate has been added, - 21~85~ ~

stirring is continued at temperature for one hour and then the reaction temperature is raised to 90C. The temperature is maintained until the isocyanate content has fallen to 1.7%, and 100 g of Solvesso~ 100 are added.
Then 500 g of heated, deionized water are added over the course of 10 minutes with vigorous stirring. This is followed immediately by the rapid dropwise addition (over about 5 min) of 3.75 g of triethylenetetramine dissolved in 37.5 g of water. After a reaction period of 3 hours at 80C, 5 ml of 25% strength ammonia solution are added and the mixture is cooled. A pasty dispersion is obtained.

Example E 5 27 g of dimethylolpropionic acid are suspended at about 80C in 100 g of polyethylene glycol 1000. 50 g of Solvesso0 100 and 27 g of Genamin~ OL 100 (ethoxylated fatty amine) are added to the suspension. The mixture is heated to 70C and then 51.2 g of tetramethylxylylene diisocyanate (TMXDI) and 37 g of tolylene diisocyanate (TDI) are added dropwise at a rate such that the temperature does not exceed 70C (about 30 min). Once all the isocyanate has been added, stirring is continued at temperature for one hour and then the reaction temperature is raised to 90C. The temperature is maintained until the isocyanate content has fallen to 1.1%. Then 400 g of heated, deionized water are added over the course of 10 minutes with vigorous stirring.
This is followed immediately by the rapid dropwise addition (over about 5 min) of 3.75 g of triethylenetetramine dissolved in 37.5 g of water. After a reaction period of 3 hours at 80C, 5 ml of 25%
strength ammonia solution are added and the mixture is cooled. A pasty dispersion is obtained.

Example D 1 140 g of the emulsifier E 1 are added to 200 g of a commercial alkyd resin having an oil content of 68%
(e.g., AlftalatX AR 680 100% alkyd resin based on ~148553 .
ricinene oil, oil length = 68) and the mixture is stirred at 70C for about 30 minutes until it is homogeneous.
Following the addition of 1 ml of 25% strength aqueous ammonia, 200 g of deionized water heated to 70C are added dropwise very slowly (about 3 hours) with vigorous stirring. A milky, structurally viscous dispersion is obtained.

Example D 2 140 g of the emulsifier E 4 are added to 200 g of a commercial alkyd resin having an oil content of 56%
(Alftalat~ SAS 560 100% alkyd resin based on soy bean oil, oil length = 56) which has been reacted with CarduraX E10 to an acid number of below 1 mg of KOH per g of resin and the mixture is stirred at 70C for about 30 minutes until it is homogeneous. Following the addition of 1 ml of 25% strength aqueous ammonia, 200 g of deionized water heated to 70C are added dropwise very slowly (about 3 hours) with vigorous stirring. A milky, structurally viscous dispersion is obtained.

Example D 3 140 g of the emulsifier E 4 are added to 200 g of a commercial alkyd resin having an oil content of 63%
(Alftalat~ AS 632 100% alkyd resin based on soy bean oil, oil length = 63) which has been reacted with Cardura2 E10 to an acid number of below 1 and the mixture is stirred at 70C for about 30 minutes until it is homogeneous.
Following the addition of 1 ml of 25% strength aqueous ammonia the mixture is poured with vigorous stirring into water heated at 70C.

Example D 4 140 g of the emulsifier E 4 are added to 200 g of a commercial oil-free polyester having an OH number of 115 and an acid number of 5 (Alftalat~ AN 950, oil length =
95) and the mixture is stirred at 70C for about 30 minutes until it is homogeneous.

Following the addition of 1 ml of 25% strength aqueous ammonia, 200 g of deionized water heated to 70C
are added dropwise very slowly (about 3 hours) with vigorous stirring. A milky, structurally viscous dispersion is obtained.
All of the other emulsifiers listed are processed in accordance with the above-described examples to give dispersions.
While the invention has been described with reference to certain preferred embodiments, numerous modifications, alterations, and changes to the preferred embodiments are possible without departing from the spirit and scope of the invention.

Claims

1. A hydrophilic polyurethane-polyurea obtained by reacting:
(A) a polyisocyanate component comprising at least one organic polyisocyanate, (B) at least one isocyanate-reactive fatty acid derivative, (C) optionally a compound other than the used (B), (D), or (E) containing more than two functional groups selected from hydroxyl and carboxyl groups, (D) a polyalkylene glycol component having a number-average molecular mass from about 500 to about 10,000 g/mol, and (E) a compound having at least one active hydrogen atom which reacts faster than water with NCO groups, while maintaining a molar ratio of isocyanate groups to the sum of hydrogen atoms of the isocyanate-reactive groups, based on all of the starting components (A) to (E), of from about 0.5:1 to about 2:1.

2. A hydrophilic polyurethane-polyurea as claimed in claim 1, wherein the molar ratio of isocyanate groups to the sum of hydrogen atoms of the hydroxyl and amino groups, based on all starting components (A) to (E), is from about 0.7:1 to about 1.5:1.

3. A hydrophilic polyurethane-polyurea as claimed in claim 1, wherein from about 0.1 to about 1 mol of component (B), from 0 to about 0.8 mol of component (C), from about 0.1 to about 0.8 mol of component (D), and from about 0.01 to about 0.3 mol of component (E) are employed per mole of component (A).

4. A polyurethane-polyurea as claimed in claim 1, wherein component (B) is unsaturated.

5. A polyurethane-polyurea as claimed in claim 1, wherein component (B) is selected from fatty alcohols, fatty amines, ethoxylated fatty alcohols or ethoxylated fatty amines having from 1 to 30 ethylene oxide units.

6. A polyurethane-polyurea as claimed in claim 1, wherein component (B) comprises an ethoxylated fatty alcohol having from 1 to 20 ethylene oxide units.

7. A polyurethane-polyurea as claimed in claim 1, wherein component (B) comprises a reaction product of a fatty acid with a polyol, wherein the polyol may contain amino groups.

8. A polyurethane-polyurea as claimed in claim 1, wherein component (B) comprises a reaction product of a fatty acid and a monoepoxide.

9. A polyurethane-polyurea as claimed in claim 1, wherein component (C) is present and comprises a bishydroxyalkanecarboxylic acid.

10. A polyurethane-polyurea as claimed in claim 1, wherein component (C) is present and comprises dimethylolpropionic acid.

11. A polyurethane-polyurea as claimed in claim 1, wherein component (D) comprises a polyalkylene ether glycol having a content of ethylene oxide units which is at least about 80% of the total alkylene oxide units.

12. A polyurethane-polyurea as claimed in claim 1, wherein component (E) comprises a diamine or polyamine.

13. A polyurethane-polyurea as claimed in claim 1, wherein the number-average molecular mass of the polyurethane-polyurea is from about 2,000 to about 20,000 g/mol, the content by mass of olefinic double bonds is from 0 to about 6%, and the content by mass of ethylene oxide units is from about 20 to about 90%.

14. An aqueous dispersion comprising a hydrophobic synthetic resin and a hydrophilic polyurethane-polyurea as claimed in claim 1 as an emulsifier.

15. An aqueous dispersion as claimed in claim 14, wherein the synthetic resin comprises an alkyd resin.

16. An aqueous dispersion as claimed in claim 14, which is free of organic solvents.

17. An aqueous dispersion as claimed in claim 14, comprising from about 20 to about 97 parts by weight of hydrophobic synthetic resin and from about 3 to about 80 parts of hydrophilic polyurethane-polyurea.

18. A coating composition comprising an aqueous dispersion as claimed in claim 14.

19. A substrate coated with a coating composition as claimed in claim 18.

20. An aqueous dispersion comprising a polyurethane-polyurea as claimed in claim 1.