EP0000381A1 - Process for the preparation of isocyanate polyaddition products containing lateral hydroxyl groups and products obtained by this process - Google Patents

Abstract

The present invention relates to a novel process for the preparation of essentially linear isocyanate polyadducts with pendant hydroxyl groups, in which essentially linear prepolymers, which have both isocyanate groups and oxazolidine groups, or a mixture comprising essentially linear NCO prepolymers and bisoxazolidines Mix with at least one mole of water per mole of oxazolidine groups present in the reaction mixture in a chain-extended manner.

Description

The present invention relates to a new process for the preparation of new isocyanate polyaddition products having pendant hydroxyl groups and to the compounds obtainable by this process.

The process according to the invention is based on the principle of reacting reactive systems containing isocyanate groups and oxazolidine groups with water, the chain extension reaction essentially taking place with formation of urea groups from the isocyanate groups and the amino groups released hydrolytically from the oxazolidines, while the hydrolytic cleavage of the oxazolidine groups also takes place comparatively inert hydroxyl groups do not participate in the reaction and are present laterally in the process products.

The principle of crosslinking reactive systems containing isocyanate groups and oxazolidine groups under the influence of moisture is already known from numerous publications (cf., for example, DT-OSs 1 952 091, 1 952 092, 2 018 233, 2 446 438, 2 458 588 or U.S. Patents 3,661,923, 3,743,626, 3 864 335 or 4 002 601). In the compositions of these publications are in general to storage stable in the absence of moisture, oxazolidines and isocyanates containing systems which react under the influence of humidity, that is under the influence of _W asserspuren to high molecular weight cross-linked structures. Due to the slow entry of water in the form of atmospheric humidity, both the amino groups and the hydroxyl groups of the hydrolytically split oxazolidine react with the isocyanate groups. This therefore leads less to chain extension reactions than to real crosslinking of the polyisocyanate component, with virtually no pendant hydroxyl groups being present in the resulting process products. Any references to the method according to the invention described below cannot be found in the publications mentioned.

• a) im wesentlichen lineare Präpolymere, welche endständig sowohl Isocyanatgruppen als auch Oxazolidingruppen oder
• b) ein im wesentlichen lineare NCO-Präpolymere und Bisoxazolidine aufweisendes Gemisch

durch Vermischen mit Wasser kettenverlängert, wobei die Wassermenge so bemessen wird, daß pro Mol an im Rekationsgemisch vorliegenden Oxazolidingruppen mindestens 1 Mol Wasser vorliegt.The present invention relates to a process for the preparation of essentially linear isocyanate polyadducts with pendant hydroxyl groups by reacting reactive systems containing free isocyanate groups and oxazolidine groups with water, characterized in that

• a) essentially linear prepolymers which are terminal both isocyanate groups and oxazolidine groups or
• b) a mixture comprising essentially linear NCO prepolymers and bisoxazolidines

chain-lengthened by mixing with water, the amount of water being measured such that at least 1 mol of water is present per mole of oxazoline groups present in the reaction mixture.

The present invention in particular also relates to an embodiment of this process in which chemically incorporated hydrophilic groups and / or prepolymers containing external emulsifiers are used as prepolymers and the water is used in such an excess that immediately aqueous dispersions or solutions of the polyadducts are formed .

The present invention finally also relates to the isocyanate polyaddition products obtainable by the process according to the invention.

The process according to the invention for the first time opens up a possibility of producing predominantly linear polyurethanes which are therefore soluble in common solvents and which have pendant hydroxyl groups and are therefore accessible to a subsequent crosslinking reaction, for example with organic polyisocyanates. Because of their linear structure, the process products according to the invention, with the simultaneous incorporation of hydrophilic groups and / or the use of external emulsifiers, can also be converted without difficulty into aqueous dispersions or solutions, from which simple, crosslinkable fabrics can then also be subsequently produced.

Starting materials for the process according to the invention are essentially linear prepolymers, which have a statistical average of 1.8 to 2.2, preferably 2, terminal isocyanate groups and generally have an average molecular weight of 500 to 10,000, preferably 800 to 4000.

The NCO prepolymers are prepared by known methods in polyurethane chemistry by reacting excess amounts of organic polyisocyanates, preferably diisocyanates, with suitable, preferably difunctional, compounds having groups which are reactive toward isocyanate groups. Starting materials for the preparation of the NCO prepolymers are accordingly

wobei Q für einen aliphatischen Kohlenwasserstoffrest mit 4 bis 12 Kohlenstoffatomen,einen cycloaliphatiachen Kohlenwasserstoffrest mit 6 bis 15 Kohlenatoffatomen, einen aromatischen Kohlenwasserstoffrest mit 6 bis 15 Kohlenstoffatomen oder einen araliphatischen Kohlenwasserstoffrest mit 7 bis 15 Kohlenstoffatomen bedeutet. Beispiele derartiger bevorzugt einzusetzender Diisocyanate sind Tetramethyhdiisocyanat, liexametliylendiisocyanat, Dodecamethylendiisocyanat, 1,4-Diisocyanato-cyclohexan, 1-Isoyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexan, 4,4'-Diisocyanatodicyclohexylmethan, 4,4'-Diisocyanato-dicyclohexylpropan-(2,2), 1,4-Diisocyanatobenzol, 2,4-Diiaocyanatotoluol, 2,6-Diisocyanatotoluol, 4,4'-Diisocyanatodiphenylmethan, 4,4'-Diiaocyanato-diphenylpropan-(2,2), p-Xylylen-diiaocyanat oder α,α,α',α'-Tetramethyl-m- oder p-xylylen-diisocyanat, sowie aus diesen Verbindungen bestehende Gemische.1. any organic polyisocyanates, preferably diisocyanates of the formula

where Q represents an aliphatic hydrocarbon radical having 4 to 12 carbon atoms, a cycloaliphatic hydrocarbon radical having 6 to 15 carbon atoms, an aromatic hydrocarbon radical having 6 to 15 carbon atoms or an araliphatic hydrocarbon radical having 7 to 15 carbon atoms. Examples of such preferred diisocyanates are tetramethyl diisocyanate, liexamethylene diisocyanate, dodecamethylene diisocyanate, 1,4-diisocyanato-cyclohexane, 1-isoyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, 4,4'-diisocyanatodicyclohexylmethane, 4,4'-diisocyanate dicyclohexylpropane- (2,2), 1,4-diisocyanatobenzene, 2,4-diiaocyanatotoluene, 2,6-diisocyanatotoluene, 4,4'-diisocyanatodiphenylmethane, 4,4'-diiaocyanato-diphenylpropane- (2,2), p- Xylylene diiaocyanate or α, α, α ', α'-tetramethyl-m or p-xylylene diisocyanate, and mixtures consisting of these compounds.

It is of course also possible to use the polyfunctional polyisocyanates known per se in polyurethane chemistry, or else modified polyisocyanates containing, for example, carbodiimide groups, allophanate groups, isocyanurate groups, urethane groups and / or biuret groups.

2. Any organic compounds with at least two groups which are reactive towards isocyanate groups, in particular a total of two amino compounds, thiol groups, carboxyl groups and / or hydroxyl groups containing organic compounds of the molecular weight range 62-10,000, preferably 1,000 to 6,000. The corresponding dihydroxy compounds are preferably used. The use of trifunctional or higher-functional compounds in the sense of the isocyanate rolyaddition reaction in small proportions to achieve a certain degree of branching is possible, as is the possible use of trifunctional or higher-functional rolyisocyanates mentioned above for the same purpose.

• Bernsteinsäure, Adipinsäure, Korksäure, Azelainsäure, Sebacinsäure, Phthalsäure. Isophthalsäure, Trimellitëäure, Phthalsäureanhydrid, Tetrahydrophthalsäureanhydrid, Hexahydrophthalsäureanhydrid, Tetrachlorphthalsäureanhydrid, Endomethylentetrahydrophthalsäureanhydrid, Glutaraäureanhydrid, Maleinsäure, Maleineäureanhydrid, Fumarsäure, dimere und trimere Fettsäuren wie Ölsäure, gegebenenfalls in Mischung mit monomeren Fettsäuren, Terephthalsäuredimethylester, Terephthalsäure-bis-glykolester. Als mehrwertige Alkohole kommen z.B. Äthylenglykol, JPropylenglykol-(1,2) und -(1,3), Butylenclykol-(1,4) und -(2,3), Hexandiol-(1,6), Octandiol-(1,8), Neopentylglykol-Cyclohexandimethanol-(1,4-Bis-hydroxymethylcyclohexan), 2-Methyl-1,3-propandiol, Glycerin, Trimethylolpropan, Hexantriol-(1,2,6), Butantriol-(1,2,4), Trimethyloläthan, Pentaerythrit, Chinit, Mannit und Sorbit, Methylglykosid, ferner Diäthylenglykol, Triäthylenglykol, Tetraäthylenglykol, Polyäthylenglykole, Dipropylenglykol, rolypropylenglykole, Dibutylenglykol und Polybutylenglykole in Frage. Die Polyester können anteilig endständige Carboxylgruppen aufweisen. Auch Polyester aus Lactonen, z.H.ε-Caprolacton oder Hydroxycarbonsäuren, z.B.ω-Hydroxycapronsäure, sind einsetzbar.

Hydroxyl compounds which are preferably used are the hydroxypolyesters, hydroxypolyethers, hydroxypolythioethers, hydroxypolyacetals, hydroxypolycarbonates and / or hydroxypolyesteramides known per se in polyurethane chemistry. The hydroxyl group-containing polyesters are, for example, reaction products of polyhydric, preferably dihydric and optionally additionally trihydric alcohols with polyhydric, preferably dihydric, carboxylic acids. Instead of the free polycarboxylic acids, the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols or mixtures thereof can be used to prepare the polyesters be used. The polycarboxylic acids can be aliphatic, cycloaliphatic, aromatic and / or heterocyclic in nature and optionally substituted, for example by halogen atoms, and / or unsaturated. Examples include:

• Succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid. Isophthalic acid, Trimellitëäure, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylenetetrahydrophthalic anhydride, Glutaraäureanhydrid, maleic acid, Maleineäureanhydrid, fumaric acid, dimeric and trimeric fatty acids such as oleic acid, optionally mixed with monomeric fatty acids, dimethyl terephthalate, terephthalic acid-bis-glykolester. Polyhydric alcohols include, for example, ethylene glycol, JP propylene glycol (1,2) and - (1,3), butylene glycol (1,4) and - (2,3), hexanediol (1,6), octanediol (1, 8), neopentyl glycol cyclohexanedimethanol- (1,4-bis-hydroxymethylcyclohexane), 2-methyl-1,3-propanediol, glycerin, trimethylolpropane, hexanetriol- (1,2,6), butanetriol- (1,2,4) , Trimethylolethane, pentaerythritol, quinite, mannitol and sorbitol, methylglycoside, also diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycols, dipropylene glycol, rolypropylene glycols, dibutylene glycol and polybutylene glycols in question. The polyesters can have a proportion of terminal carboxyl groups. Polyesters made from lactones, zHε-caprolactone or hydroxycarboxylic acids, for example ω-hydroxycaproic acid, can also be used.

The polyethers which are preferred according to the invention and preferably have two hydroxyl groups are those of the type known per se and are obtained, for example, by polymerization of epoxides such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin with themselves, for example in the presence of BF ₃ , or by adding these epoxides, optionally in a mixture or in succession, to starting components with reactive water atoms such as alcohols and amines, for example water, ethylene glycol, (1,3) or - (1,2), 4,4'-dihydroxy-diphenylpropane, Aniline.

Polyethers modified by vinyl polymers, e.g. by polymerization of styrene or acrylonitrile in the presence of polyethers (American patents 3,383,351, 3,304,273, 3,523,093, 3,110,695, German patent 1,152,536) are also suitable. The proportionally higher-functionality polyethers to be used, if appropriate, are formed in an analogous manner by known alkoxylation of higher-functionality starter molecules, e.g. Ammonia, ethanolamine, ethylenediamine or sucrose.

Among the polythioethers, the condensation products of thiodiglycol with itself and / or with other glycols, dicarboxylic acids, formaldehyde, aminocarboxylic acids or amiroalcohols should be mentioned in particular. Je nacl. the CO components, the products are polythio ether, tolythio ether, polythio ether anude.

As polyacetals e.g. the compounds which can be prepared from glycols, such as diethylene glycol, triethylene glycol, 4,4'-diethoxy-diphenyldimethylmethane, hexanediol and formaldehyde. Polyacetals suitable according to the invention can also be prepared by polymerizing cyclic acetals.

Suitable polycarbonates having hydroxyl groups are those of the type known per se. e.g. by reacting diols such as propanediol (1,3), butanediol (1.4) and / or hexanediol (1,6), diethylene glycol, triethylene glycol, tetraethylene glycol with diaryloarbonates, e.g. Diphenyl carbonate, or phosgene, can be produced.

The polyester amides and polyamides include e.g. the predominantly linear condensates obtained from polyvalent saturated and unsaturated carboxylic acids or their anhydrides and polyvalent saturated and unsaturated amino alcohols, diamines, polyamines and their mixtures. Polyhydroxyl compounds already containing urethane or urea groups can also be used.

Low molecular weight polyols can also be used, e.g. Ethanediol, rropanediol-1,2 and -1,3, butanediol-1,4 and -1,3, pentanediols, hexardiols, trimethylolpropane, hexanetriols, glycerol and fentaerythritol.

Representatives of the poly (cyanate) and hydroxyl compounds to be used in the process according to the invention are e.g. in High Polymers, Vol. XVI, "Polyurethanes, Chemistry and Technology", written by Saunders-Frisch, Interacience Publiahers, New York, London, Volume I, 1962, pages 32-42 and pages 44-54 and Volume II, 1964, Pages 5-6 and 198-199, as well as in the plastics manual, volume VII, Vieweg-Höchtlen, Carl-Hanser-Verlag, Munich, 1966, e.g. on pages 45 to 71.

If hydrophilically modified prepolymers are to be used in the process according to the invention in accordance with the above-mentioned special embodiment, their preparation takes place according to known processes of the prior art, for example according to those in DT-OSs 1 495 745, 1 495 847, 2 446 440, 2 340 512, _U S-PS 3 479 310, GB-PS'en 1 158 088 or 1 076 688 described methods. This means that in the preparation of the prepolymers, in addition to the starting materials already mentioned by way of example, chemically fixed hydrophilic groups, preferably in the sense of the isocyanate additine reaction, mono- and in particular difunctional structural components of the type described in the above-mentioned references regarding the production of aqueous polyurethane dispersions or solutions, ie diisocyanates, diamines or dihydroxy compounds or diisocyanates or glycols containing ionic or potential ionic groups or polyethylene oxide units, for example, are also used.

The preferred hydrophilically modified structural components include in particular the sulfonate group-containing aliphatic diols according to _DT - _O S 2 446 440, the cationic or also anionic internal emulsifiers which can be incorporated according to German patent application P 26 51 506.0 and also the monofunctional incorporable polyethers described in this patent application.

In the preparation of the NCO prepolymers according to known principles of the prior art, the reactants are generally used in such proportions that a ratio of isocyanate groups to hydrogen atoms reactive towards NCO, preferably from hydroxyl groups, from 1.05 to 10, preferably from 1.1 to 3 correspond.

The order in which the individual reaction partners are added is largely arbitrary. You can either mix the hydroxyl compounds and add the polyisocyanate, or you can gradually add the mixture of hydroxyl compounds or the individual hydroxyl compounds to the polyisocyanate component.

The NCO prepolymers are preferably produced in the melt at 30 to 190 ^° C., preferably at 50 to 120 ^° C. Of course, the prepolymers could also be produced in the presence of organic solvents.

Suitable solvents, e.g. in an amount up to 25% by weight, based on the solid, could be used e.g. Acetone, methyl ethyl ketone, ethyl acetate, dimethylformamide or cyclohexanone.

• a) eine mittlere NCO-Funktionalität von 1,8 bis 2,2, vorzugsweise 2,
• b) einen Gehalt an kationischen oder anioniachen eingebauten Gruppen von 0 bis 100, vorzugsweise 0,1 bis 100 und insbesondere 0,5 bis 50 Milli-Äquivalent pro 100 g Feststoff,
• c) einen Gehalt an seitenständig, endständig und/oder innerhalb der Hauptkette eingebauten, innerhalb eines Polyäthersegments vorliegenden Äthylenoxid-Einheiten von 0 bis 30, vorzugsweise 0,5 bis 30 und insbesondere 1 bis 20 Gew.-%, bezogen auf das Gesamtgewicht des Präpolymeren und
• d) ein mittleres Molekulargewicht von 500 bis 10.000, vorzugsweise 800 bis 4.000 aufweisen.

The nature and proportions of the starting materials used in the preparation of the NCO prepolymers are preferably chosen so that the NCO prepolymers

• a) an average NCO functionality of 1.8 to 2.2, preferably 2,
• b) a content of cationic or anionic groups from 0 to 100, preferably 0.1 to 100 and in particular 0.5 to 50 milliequivalents per 100 g of solid,
• c) a content of laterally, terminally and / or incorporated within the main chain, present within a polyether segment of ethylene oxide units from 0 to 30, preferably 0.5 to 30 and in particular 1 to 20 wt .-%, based on the total weight of the prepolymer and
• d) have an average molecular weight of 500 to 10,000, preferably 800 to 4,000.

As already stated, the preferred NCO prepolymers include those which are either ionic groups of the type mentioned under b), ie in particular —COO ^- , —SO ₃ ^- or = N ⁺ =, or nonionic groups of the type mentioned under c) or have both ionic and nonionic groups of the type mentioned. However, it is also possible to use NCO prepolymers in the process according to the invention, in the production of which none of the hydrophilic structural components mentioned under 3, were used, in which the content of the groups mentioned under b) or c) is therefore 0.

If such NCO prepolymers are used, which moreover have the properties mentioned under a) and d) above, the preparation of aqueous dispersions or solutions of the process products according to the invention is only possible when carrying out the process according to the invention if external emulsifiers are also used . Suitable such emulsifiers are described, for example, by R. Heusch in "Emulsions", Ullmann, Volume 10, pages 449-473, Weinheim 1975. Both ionic emulsifiers such as e.g. Alkali and ammonium salts of long-chain pet acids or long-chain aryl (alkyl) sulfonic acids, as well as non-ionic emulsifiers such as e.g. ethoxylated alkylbenzenes with an average molecular weight of 500 to 10,000.

These external emulsifiers are thoroughly mixed with the NCO-Pril polymers before the process according to the invention is carried out. They are generally used in amounts of 1 to 30, preferably 5 to 20 parts by weight, based on the weight of the NCO prepolymer. It is also possible to increase the hydrophilicity of the hydrophilic modified NCO prepolymers by using such external emulsifiers, although this is generally not necessary.

As already explained, the incorporation of hydrophilic groups or the use of external emulsifiers is not absolutely necessary when carrying out the process according to the invention, but generally only takes place if the process products according to the invention are to be obtained in the form of aqueous dispersions or solutions. It is therefore entirely conceivable for the method according to the invention for example in the solvent mentioned above by way of example, solutions of the process products according to the invention then being obtained in these solvents.

aufweisen, wobei

• R₁ und R₂ für gleiche oder verschiedene Reste stehen und Wasserstoff, aliphatische Kohlenwasserstoffreste mit 1-4 Kohlenstoffatomen, cycloaliphatische Kohlenwasserstoffreste mit 5-7 Kohlenstoffatomen oder aromatische Kohlenwasserstoffreste mit 6-10 Kohlenstoffatomen bedeuten bzw. zusammen mit dem Ring-Kohlenstoffatom gemeinsam einen 5- oder 6- gliedrigen cycloaliphatischen KohlenwasserstoffRing bilden können,
• X für einen Rest der Formel
  
  steht, wobei R₃ und R₄ für gleiche oder verschiedene Reste stehen und C₁-C₄-Alkylreste, vorzugsweise jedoch Wasserstoff bedeuten und m 2 oder 3 bedeuten,
• Y für einen Rest der Formel
  
  steht, in welcher R₃ und R₄ die bereits genannte Bedeutung haben und n für eine ganze Zahl von 2 bis 6 steht.

The above-mentioned NCO prepolymers with 1.8-2.2, preferably 2, terminal isocyanate groups are preferably used in the process according to the invention in a mixture with bisoxazolidines. "Bisoxazolidines" are to be understood here as meaning any organic compounds which have 2 oxazolidine groups which form a hydroxyl and a secondary amino group under the influence of water and are otherwise inert under the conditions of the process according to the invention. The preferred bisoxazolidines include those which have 2 groups of the formula

have, where

• R ₁ and R _{2 represent} identical or different radicals and are hydrogen, aliphatic hydrocarbon radicals with 1-4 carbon atoms, cycloaliphatic hydrocarbon radicals with 5-7 carbon atoms or aromatic hydrocarbon radicals with 6-10 carbon atoms or together with the ring carbon atom together represent a 5- or can form a 6-membered cycloaliphatic hydrocarbon ring,
• X for a residue of the formula
  
  where R ₃ and R _{4 are the} same or different radicals and are C ₁ -C ₄ alkyl radicals, but preferably hydrogen and m are 2 or 3,
• Y for a residue of the formula
  
  stands in which R ₃ and R _{4 have} the meaning already mentioned and n stands for an integer from 2 to 6.

verknüpft sind, wobei

• A und A' für gleiche oder verschiedene Reste stehen und -COO- oder -OCO-NH- bedeuten und
• Z für einen zweiwertigen aliphatischen Kohlenwasserstoffrest mit 2-14 Kohlenstoffatomen, einen zweiwertigen cycloaliphatischen Kohlenwasserstoffrest mit 5-14 Kohlenstoffatomen oder einen Arylenrest mit 6-15 Kohlenstoffatomen steht.

The particularly preferred bisoxazolidines include those in which 2 radicals of the above formula have a divalent radical of the formula

are linked, whereby

• A and A 'represent the same or different radicals and are -COO- or -OCO-NH- and
• Z represents a divalent aliphatic hydrocarbon radical with 2-14 carbon atoms, a divalent cycloaliphatic hydrocarbon radical with 5-14 carbon atoms or an arylene radical with 6-15 carbon atoms.

In the process according to the invention, either mixtures of the exemplified NCO prepolymers with the exemplified bisoxazolidines or predominantly linear prepolymers containing isocanate groups and oxazolidine groups are used.

in welcher

• R₁, R₂, X und Y die bereits genannte Bedeutung haben,hergestellt werden.

These latter prepolymers can be obtained in a simple manner by reacting the predominantly difunctional NCO prepolymers mentioned above with hydroxyl-containing oxazolidines of the formula

in which

• R ₁ , R ₂ , X and Y have the meaning already mentioned, are produced.

In this preparation of the prepolymers containing isocyanate groups and oxazolidines, the reactant partners are preferably used in proportions such that 0.37-0.53, preferably 0.4-0.51 mol, hydroxyl groups of the hydroxyoxyzolidine are accounted for per mole of isocyanate groups of the NCO prepolymer. This gives reaction mixtures which have about 0.6-1.1, preferably about 0.65-1.05, oxazoline groups per remaining isocyanate group. Since the monohydroxyoxazolidines are monofunctional compounds, there is no appreciable increase in molecular size in this reaction. The reaction products are therefore also just like the NCO prepolymers used as starting materials essentially linear connections.

Both the hydroxyoxazolidines and the bisoxazolidines mentioned are compounds known from the literature (see, for example, the references mentioned at the beginning with regard to the moisture-curing oxazolidine compositions of the prior art). Bisoxazolidines or hydroxyoxazolidines to be used with particular preference are the corresponding compounds mentioned in US Pat. No. 4,002,601 or DT-OS 2,446,438.

The N-hydroxyalkyl oxazolidines are prepared by methods known from the literature, a ketone or an aldehyde being condensed with a bis- (hydroxyalkyl) amine with cyclizing dehydration and the water of reaction being removed azeotropically by an inert entrainer or by the excess carbonyl compound becomes.

eignen sich insbesondere nachstehend aufgeführte Aldehyde und Ketone:

• Formaldehyd, Acetaldehyd, Propionaldehyd, Butyraldehyd, Isobutyraldehyd, Benzaldehyd, Tetrahydrobenzaldehyd, Aceton, Methyläthylketon, Methylpropylketon, Methylisopropylketon, Diäthylketon, Methylbutylketon, Methylisobutylketon, Methylt-butylketon, Diisobutylketon, Cyclopentanon und Cyclohexanon. Bevorzugt einzusetzende Carbonylverbindungen sind entsprechend der vorstehenden Definition der bevorzugten Reste R, und R₂ Formaldehyd sowie die genannten aliphatischen Aldehyde bzw. Ketone.

As carbonyl compounds

Aldehydes and ketones listed below are particularly suitable:

• Formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, benzaldehyde, tetrahydrobenzaldehyde, acetone, methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, diethyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl t-butyl ketone, cycloshexanone ketone and diisobopentyl ketone. According to the above definition of the preferred radicals R, and R ₂ , carbonyl compounds to be used with preference are formaldehyde and the aliphatic aldehydes or ketones mentioned.

eignen sich besonders Bis-(2-hydroxyäthyl)-amin und Bis-(2-hydroxypropyl)-amin. Im Prinzip ebenso geeignet sind jedoch auch beispielsweise Bis-(2-hydroxybutyl)-amin, Bis-(2-hydroxyhexyl)-amin, Bis-(3-hydroxyhexyl)-amin, oder N-(2-hydroxypropyl)-N-(6-hydroxyhexyl)-amin.As bis (hydroxyalkyl) amines

Bis- (2-hydroxyethyl) amine and bis- (2-hydroxypropyl) amine are particularly suitable. In principle, however, bis- (2-hydroxybutyl) amine, bis (2-hydroxyhexyl) amine, bis (3-hydroxyhexyl) amine, or N- (2-hydroxypropyl) -N- ( 6-hydroxyhexyl) amine.

(in der Z die oben angegebene Bedeutung besitzt) z.B. Hexamethylendiisocyanat, 3,3,5-Trimethyl-5-isocyanatomethyl- cyclohexylisocyanat (IPDI), 4,4'-Diisocyanato-dicyclohexylmethan, 2,4- und 2,6-Diisocyanatotoluol oder 4,4'-Diisocyanatodiphenylmethan herstellen. Auch die Umsetzung mit Dicarbonsäuren, aliphatischer, cycloaliphatischer oder aromatischer Natur der Formel

führt zu erfindungsgemäß einsetzbaren, Estergruppen aufweisenden Bisoxazolidinen.Starting from the hydroxyoxazolidines described above, the bisoxazolidines to be used according to the invention, preferably having urethane groups, can be reacted with diisocyanates of the formula

(in which Z has the meaning given above), for example hexamethylene diisocyanate, 3,3,5-trimethyl-5-isocyanatomethylcyclohexyl isocyanate (IPDI), 4,4'-diisocyanatodicyclohexylmethane, 2,4- and 2,6-diisocyanatotoluene or Prepare 4,4'-diisocyanatodiphenylmethane. Also the reaction with dicarboxylic acids, aliphatic, cycloaliphatic or aromatic in nature of the formula

leads to bisoxazolidines containing ester groups which can be used according to the invention.

In addition to the dicarboxylic acids, their bischlorides can also be used with the elimination of HCl or the bisesters with the elimination of alcohol. In addition, it is possible to use the OH- To implement group with stoichiometric amounts of hydroxycarboxylic acids or the corresponding lactones. The use of, for example, hydroxypropionic acid, hydroxybutyric acid, hydroxycaproic acid, etc., or their lactones, can be used here. However, this additional modification is less preferred.

• a) die beispielhaft genannten Oxazolidin- und Isocyanatgruppen aufweisenden Präpolymeren oder
• b) Gemische der beispielhaft genannten NCO-Präpolymeren mit den beispielhaft genannten Bisoxazolidinen, in welchen die Mengenverhältnisse der Komponenten im allgemeinen so gewählt sind, daß für jedes Mol Isocyanatgruppen 0,6 bis 1,1, vorzugsweise 0,65 bis 1,05, Mol Oxazolidingruppen vorliegen,

mit Wasser vermischt. Hierbei wird das Wasser nicht wie in den eingangs genannten Vorveröffentlichungen in Form von Luftfeuchtigkeit sondern in flüssiger Form eingesetzt. Wesentlich ist hierbei, daß die Wassermenge so bemessen wird, daß sie mindestens zur Hydrolyse der Oxazolidingruppen ausreicht, d.h. daß pro Mol Oxazolidingruppen mindestens 1 Mol Wasser zum Einsatz gelangt. Im allgemeinen wird man jedoch stets einen mindestens 100 %igen Überschuß über diese Menge an Wasser einsetzen, selbst wenn nicht die Herstellung von wäßrigen Dispersionen oder Lösungen der erfindungsgemäßen Verfahrensprodukte sondern beispielsweise deren Lösungen in organischen Lösungsmitteln hergestellt werden sollen. Durch den Zusatz des Wassers in flüssiger Form und durch die genannte Wassermenge wird eine Additionsreaktion zwischen den Isocyanatgruppen und den aus den Oxazolidingruppen hydrolytisch gebildeten Hydroxylgruppen weitgehend ausgeschlossen, da selbst bei Verwendung eines Oxazolidin-Unterschusses bezogen auf Isocyanatgruppen dann stets eine Kettenverlängerungsreaktion zwischen den Isocyanatgruppen und dem überschüssig vorliegenden Wasser im Vergleich zur Additionsreaktion zwischen Isocyanatgruppen und Hydroxylgruppen vorrangig abläuft. Bei der Herstellung von wäßrigen Lösungen bzw. Dispersionen bei der Durchführung des erfindungsgemäßen Verfahrens wird das Wasser im allgemeinen in Mengen von 4₀ bis 300 , vorzugsweise 55 bis 230 Gew.%, bezogen auf Oxazolidin- und Isocyanatgruppen aufweisendes Reaktivsystem eingesetzt.When carrying out the method according to the invention

• a) the prepolymers containing the exemplified oxazolidine and isocyanate groups or
• b) Mixtures of the exemplified NCO prepolymers with the exemplified bisoxazolidines, in which the proportions of the components are generally chosen so that for every mole of isocyanate groups 0.6 to 1.1, preferably 0.65 to 1.05, mol Oxazolidine groups are present,

mixed with water. Here, the water is not used in the form of atmospheric moisture, as in the previous publications mentioned at the beginning, but in liquid form. It is important here that the amount of water is such that it is at least sufficient for the hydrolysis of the oxazolidine groups, ie that at least 1 mole of water is used per mole of oxazoline groups. In general, however, an at least 100% excess over this amount of water will always be used, even if it is not the production of aqueous dispersions or solutions of the process products according to the invention but, for example, that their solutions are to be prepared in organic solvents. By adding the water in liquid form and by the amount of water mentioned there is an addition reaction between the isocyanate groups and the hydroxyl groups formed hydrolytically from the oxazolidine groups is largely ruled out, since even when using an oxazolidine deficit based on isocyanate groups, a chain extension reaction between the isocyanate groups and the excess water always takes place in comparison to the addition reaction between isocyanate groups and hydroxyl groups. In the preparation of aqueous solutions or dispersions in the process of the invention the water generally in amounts of from 4 ₀ to 300, preferably 55-230 wt.%, Based on oxazolidine and isocyanate groups reactive system used.

• Das Isocyanatgruppen und Oxazolidingruppen aufweisende Reaktivgemisch wird in einem geeigneten Lösungsmittel, welches vorzugsweise mit Wasser mischbar sein sollte, zu einer 5 bis 95 , vorzugsweise 20 bis 70 gew.-%igen Lösung gelöst. Zu dieser Lösung wird dann unter Rühren das Wasser als solches oder im Gemisch mit mit Wasser mischbarem Lösungsmittel zugesetzt. Die Temperatur hierbei liegt im allgemeinen zwischen O und 80°c. Es bildet sich dann sofort eine Lösung des erfindungsgemäßen Verfahrensprodukts in dem Lösungsmittel bzw. Lösungsmittel/Wasser-Gemisch. Geeignete Lösungsmittel sind beispielsweise Dimethylformamid, Dimethylsulfoxid, Aceton, Methyläthylketon oder aber auch Gemische von beispielsweise tertiären Alkoholen wie tert.-Butanol mit aromatischen Lösungsmitteln wie z.B. Toluol.

In the preparation of solutions of the process products according to the invention in organic solvents, the procedure for carrying out the process according to the invention is generally as follows:

• The reactive mixture containing isocyanate groups and oxazolidine groups is dissolved in a suitable solvent, which should preferably be miscible with water, to give a 5 to 95, preferably 20 to 70% by weight solution. The water as such or in a mixture with water-miscible solvent is then added to this solution with stirring. The temperature here is generally between 0 and 80 ° C. A solution of the process product according to the invention is then immediately formed in the solvent or solvent / water mixture. Suitable solvents are, for example, dimethylformamide, dimethyl sulfoxide, acetone, methyl ethyl ketone or else mixtures For example, tertiary alcohols such as tert-butanol with aromatic solvents such as toluene.

In the particularly preferred embodiment of the process according to the invention with simultaneous production of aqueous dispersions or solutions of the process products according to the invention in water, either the reactive system which has been hydrophilically modified as described or contains an external emulsifier, in particular if it is a liquid, is mixed directly with the water stirred, or one proceeds according to the principle set out above with the use of an auxiliary solvent, the auxiliary solvent advantageously being a water-miscible solvent having a boiling point below 100 ° C., which can be removed by distillation after the reaction according to the invention has taken place. In this production of aqueous dispersions or solutions, the dispersion or dissolution of the prepolymers and their chain extension take place practically simultaneously. A decisive advantage over the previously known methods of the prior art for the solvent-free or low-solvent production of aqueous polyurethane dispersions is that intimate mixing with the chain extender takes place before the prepolymers are brought into contact with the water, or even before they are brought into contact with water The chain-extending group (oxazolidine group) is chemically fixed, so that the chain extension leads to particularly homogeneous products. The process according to the invention is particularly suitable for the production of aqueous dispersions or solutions which have a solids content of 10 to 70, preferably 30 to 65,% by weight.

The particles of the discontinuous phase in the dispersions generally have a diameter of 50 to 1000 nm. The production of sols with an average particle diameter of the discontinuous phase of about 1-50 nm or clear, aqueous solutions in which the solid is present in molecularly disperse form or at most in the form of associates is also possible according to the invention.

Whether or not solutions or dispersions of the polyurethanes in water are obtained in the process according to the invention depends above all on the molecular weight and the hydrophilicity of the dissolved or dispersed particles, which in turn depends on the suitable choice of type and quantitative ratios of the starting materials, in particular in the preparation of the NCO prepolymers , can be adjusted according to the known principles of polyurethane chemistry. For example, the use of an NCO prepolymer with a mean NCO functionality slightly below 2 leads to the polyaddition reaction being terminated before excessively high molecular weights are reached. The polyurethanes produced by the process according to the invention and present in aqueous dispersion or solution are on a par with the known polyurethanes produced in organic solvents. Films made from them have excellent mechanical strength and hydrolysis resistance and can be used for a wide variety of applications.

Because of the pendant hydroxyl groups built into the process products according to the invention, these can be shaped after shaping, for example by evaporation of the solvent or water after the solution or the dispersion a chemically or thermally activated crosslinking agent was added to cross-link _l. Suitable crosslinking agents are, for example, polyisocyanates with blocked isocyanate groups or melamine resins which are reactive towards hydroxyl groups. Even if the process products according to the invention are not chemically crosslinked via the pendant hydroxyl groups, these can be advantageous since they often increase the physical affinity of the process products according to the invention for substrates which are coated with the compounds according to the invention

All parts mentioned in the following examples are parts by weight.

example

eingerührt und die Mischung anschließend unter kräftigem Rühren mit 5060 Teilen entionten Wassers versetzt. Die entstandene wäßrige Dispersion hatte einen Feststoffgehalt von 30 % und eine Viskosität von 14 Sekunden (Fordbecher, 4 mm). Sie zeigte im durchscheinenden Licht einen Tyndall-Effekt. Die Dispersion trocknet zu einem klaren, farblosen und klebfreien Film auf, der folgende mechanische Daten besitzt:1237.5 parts of a polybutylene adipate (MW = 2250) and 191.3 parts of a four-propoxylated adduct of 2-butenediol-1,4 and sodium bisulfite (MW = 425), hereinafter referred to as "adduct", were at 120 ° C in Water jet vacuum dewatered 488.4 parts of 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane were added to this mixture at 70 ° C. and the mixture was stirred after raising the temperature to 100 ° C. until the NCO content of the Melt was 5.3%. After cooling to 60 ° C, 437.4 parts of a bisoxazolidine of the formula

stirred in and then mixed with vigorous stirring with 5060 parts of deionized water. The resulting aqueous dispersion had a solids content of 30% and a viscosity of 14 seconds (Ford cup, 4 mm). It showed a Tyndall effect in the translucent light. The dispersion dries to a clear, colorless and tack-free film, which has the following mechanical data:

Tensile strength: 37.2 MPa

Elongation at break: 620%

330 parts of the dispersion were mixed with 15 parts of a hexamethyl / butyloxymethylmelamine and cast into a film. After drying, the film was heated to 130 ° C for 20 minutes. The mechanical values measured on this film were:

Tensile strength: 45.3 MPa

Elongation at break: 410%

The film was not sticky after moistening with toluene and acetone and did not dissolve in hot DMF.

Example 2

versetzt. Unter kräftigem Rühren wurden 5100 Teilen entionten Wassers zugegeben. Die entstandene Dispersion hatte einen Festkörpergehalt von 30 % und eine Viskosität von 18 Sekun- . den (Fordbecher, 4 mm). Sie zeigte im durchscheinenden Licht einen Tyndall-Effekt.The NCO prepolymer from Example 1 was at 60 ° C with 361.8 parts of a bisoxazolidine of the formula

transferred. 5100 parts of deionized water were added with vigorous stirring. The resulting dispersion had a solids content of 30% and a viscosity of 18 seconds. den (Ford cup, 4 mm). It showed a Tyndall effect in the translucent light.

The dispersion dries to a clear, colorless and tack-free film which, after the water has been completely removed, has a Shore A hardness of 78. After heating to 130 ° C. for 20 minutes, the hardness had risen to 85 (Shore-A) and the film was only swellable in hot DMF, but no longer soluble.

Example 3

eingerührt und die Mischung anschließend unter kräftigem Rühren mit 4070 Teilen entionten Wassers versetzt. Die entstandene wäßrige Dispersion hatte einen Feststoffgehalt von 30 % und eine Viskosität von 15 Sekunden (Fordbecher, 4 mm). Die Dispersion zeigte im durchscheinenden Licht einen Tyndall-Effekt. Die Dispersion trocknete nach dem Vergießen zu einem klaren, harten Film auf, der jedoch mit dem Fingernagel leicht zu ritzen war. Die Bleistifthärte betrug HB-H. Nach 20-minütigem Erhitzen auf 130°C war die die auf 3 H angestiegen.600 parts of a polyethylene diol phthalate (MG-2000) and 525 parts of a polyethylene diol phthalate adipate (MG-1750) and 170.4 parts of the adduct described in Example 1 were dewatered at 120 ° C. in a water jet vacuum. 285.6 parts of hexamethylene diisocyanate were added to this mixture at 70 ° C. and the mixture was raised after the temperature had risen Stirred 100 ° C until the _NCO content of the melt was 4.8%. After cooling to 80 ° C 209 parts of an oxazolidine of the formula

stirred in and the mixture then mixed with vigorous stirring with 4070 parts of deionized water. The resulting aqueous dispersion had a solids content of 30% and a viscosity of 15 seconds (Ford cup, 4 mm). The dispersion showed a Tyndall effect in the translucent light. After pouring, the dispersion dried into a clear, hard film, which was easy to scratch with a fingernail. The pencil hardness was HB-H. After heating at 130 ° C. for 20 minutes, the temperature had risen to 3 hours.

Example 4

eingerührt und die Mischung anschließend unter kräftigem Rühren mit 2230 Teilen entionten Wassers versetzt. Es entstand eine wäßrige Dispersion mit einem Feststoffgehalt von 40 % und einer Viskosität von 20 Sekunden (Fordbecher, 4 mm). Die Dispersion zeigte im durchscheinenden Licht einen Tyndall-Effekt.300 parts of a Polyäthandiolphthalats (MW = 2000) and 612.5 parts of a Polyäthandiolphthaladadipates (MG-1750) and 13.4 parts of 1,1,1-trishydroxymethylpropane and 148.8 parts of the adduct described in Example 1 were at 120 ° C in Water jet vacuum drained. 285.6 parts of hexamethylene diisocyanate were added to this mixture at 70 ° C. and the mixture was stirred after the temperature had been raised to 100 ° C. until the NCO content of the melt was 4.3%. After cooling to 80 ° C, 252.7 parts of an oxazolidine of the formula

stirred in and then mixed with vigorous stirring with 2230 parts of deionized water. The result was an aqueous dispersion with a solids content of 40% and a viscosity of 20 seconds (Ford cup, 4 mm). The dispersion showed a Tyndall effect in the translucent light.

Example 5

eingerührt und die Mischung anschließend unter kräftigem Rühren mit 6160 Teilen entionten Wassers versetzt. Die entstandene Dispersion hatte einen Festkörpergehalt von 30 %. Die Dispersion zeigte im durchscheinenden Licht einen Tyndall-Effekt.1000 parts of an ethanediol / 1,4-butanediol / diethylene glycol polyadipate (MW = 2000) and 1100 parts of an adduct from stoichiometric amounts (i) of a polyether alcohol started on n-butanol and consisting of 83% ethylene oxide and 17% propylene oxide (MG - 1900) , (ii) hexamethylene diisocyanate and (iii) diethanolamine were dewatered at 120 ° C in a water jet vacuum. 369.2 parts of hexamethylene diisocyanate were added to this mixture and, after the temperature had been raised to 100 ° C., the mixture was stirred until the NCO content of the melt was 4.1%. After cooling to 30 ° C, 358.2 parts of an oxazolidine of the formula

stirred in and then mixed with vigorous stirring with 6160 parts of deionized water. The resulting dispersion had a solids content of 30%. The dispersion showed a Tyndall effect in the translucent light.

Example 6

eingerührt und die Mischung anschließend unter kräfigem Rühren mit 3320 Teilen entionten Wassers versetzt. Die entstandene Dispersion hatte einen Festkörpergehalt von 40 % und eine Viskosität von 18 Sekunden (Fordbecher, 4 mm). Sie zeigte im durchscheinenden Licht einen Tyndall-Effekt. Die Dispersion trocknet zu einem klaren, farblosen und elastischen Film auf, der folgende mechanische Daten besitzt:1192.5 parts of a polybutanediol adipate (MW-2250) and 137.5 parts of a propylene started on bisphenol A. oxide polyether (MW = 550) and 85.5 parts of a polyether alcohol started on n-butanol from 85% ethylene oxide and 15% propylene oxide and 85.2 parts of the adduct described in Example 1 were dewatered at 120 ° C. in a water jet vacuum. 488.4 parts of 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane were added to this mixture at 70 ° C., and the mixture was stirred after the temperature had been raised to 100 ° C. until the NCO content was 5.0 % amounted to. After cooling to 60 ° C, 437.4 parts of a bisoxazolidine of the formula

stirred in and then mixed with vigorous stirring with 3320 parts of deionized water. The resulting dispersion had a solids content of 40% and a viscosity of 18 seconds (Ford cup, 4 mm). It showed a Tyndall effect in the translucent light. The dispersion dries to a clear, colorless and elastic film, which has the following mechanical data:

Tensile strength: 28.6 MPa

Elongation at break: 930%

250 parts of the dispersion were mixed with 20 parts of a butanone-capped triisocyanatohexylbiuret. After a film had dried on, it was heated to 160 ° C. for 30 minutes. The mechanical data measured on this film were:

Tensile strength: 41.7 MPa

Elongation at break: 430%

Example 7

eingerührt und die Mischung anschließend unter kräftigem Rühren mit einer Mischung aus 2260 Teilen entionten Wassers und 76 Teilen Äthylenglykolmonoäthylester versetzt. Es bildete sich eine Dispersion mit einem Festkörpergehalt von 40 %. Sie zeigte im durchscheinenden Licht einen Tyndall-Effekt.500 parts of a polyethylene phthalate (MW = 2000) and 332 Parts of a polypropylene glycol ether (MW = 550) started on bisphenol A and 13.4 parts of trishydroxymethylpropane and 104 parts of the adduct described in Example 1 were dewatered at 120 ° C. in a water jet vacuum. 320 parts of hexane diisocyanate were added to this mixture at 70 ° C. and the mixture was stirred after the temperature had been raised to 100 ° C. until the NCO content was 4.7%. After cooling to 40 ° C, 246 parts of an oxazolidine of the formula

stirred in and then mixed with vigorous stirring with a mixture of 2260 parts of deionized water and 76 parts of ethylene glycol monoethyl ester. A dispersion with a solids content of 40% was formed. It showed a Tyndall effect in the translucent light.

Example 8

und 84 Teilen Äthylenglykolmonoäthyläther wurden unter kräftigem Rühren 2500 Teile entionten Wassers zugesetzt. Es entstand eine Dispersion mit einem Festkörpergehalt von 38 %. Sie zeigte im durchscheinenden Licht einen Tyndall-Effekt. Nach dem Ausgießen und Auftrocknen bildete sich ein klarer zäher Film, der hohe Härte besaß.552 parts of a polypropylene glycol ether (MW = 550) started on bisphenol A were dewatered at 120 ° C. in a water jet vacuum and mixed at 70 ° C. with 320 parts of hexane diisocyanate. After the temperature had been raised to 100 ^° C., the mixture was stirred until the NCO content was 8.7. The mixture was cooled to 50 ° C and 238 parts of an adduct of 20 moles of ethylene oxide with 1 mole of iso-nonylphenol were dissolved in it. After adding 320 parts of an oxazolidine of the formula

and 84 parts of ethylene glycol monoethyl ether, 2500 parts of deionized water were added with vigorous stirring. A dispersion with a solids content of 38% was formed. It showed a Tyndall effect in the translucent light. After pouring out and drying, a clear, tough film was formed which was extremely hard.

Example 9

12 Stunden lang gerührt. Darauf wurden 105 Teile Äthylenglykolmonoäthyläther zugesetzt und bei 50⁰C 1590 Teile entionten Wassers eingerührt. Die entstandene Dispersion hatte einen Festkörpergehalt von 40 % und zeigte im durchscheinenden Licht einen Tyndall-Effekt. Sie trocknete zu einem klaren zähen und glänzenden Film auf.556 parts of a polypropylene glycol ether (MW = 550) started on bisphenol A and 93.6 parts of the adduct described in Example 1 were dewatered at 120 ° C. in a water jet vacuum. 320 parts of hexane diisocyanate were added to this mixture at 70 ° C. and the mixture was stirred after the temperature had been raised to 100 ° C. until the NCO content was 6.3%. At 70 ° C after mixing with 80 parts of an oxazolidine of the formula

Stirred for 12 hours. Thereupon, 105 parts of ethylene glycol monoethyl ether were added and stirred in 1590 parts water at 50 ⁰ C entionten. The resulting dispersion had a solids content of 40% and showed a Tyndall effect in the translucent light. It dried into a clear, tough and shiny film.

Claims (3)

1) Process for the preparation of essentially linear isocyanate polyadducts having pendant hydroxyl groups by reacting reactive systems containing free isocyanate groups and oxazolidine groups with water, characterized in that a) essentially linear prepolymers which are terminal both isocyanate groups and oxazolidine groups or b) a mixture comprising essentially linear NCO prepolymers and bisoxazolidines
chain extended by mixing with water, wherein the amount of water is dimensioned such that at least 1 mol per mol of _'water is present in present in the reaction mixture oxazolidine. 2) Method according to claim 1, characterized in that the prepolymers used are hydrophilically modified and / or an external emulsifier-containing prepolymers and a large excess of water with respect to the chain extension reaction, so that an aqueous dispersion or solution of the polyadducts is obtained directly. 3) Isocyanate polyaddition products which contain pendant hydroxyl groups and are obtainable according to claim 1.