Process for the preparation of stabilized polyamines, stabilized polyamines with retarded reactivity and their use in the preparation of polyurethane.

The invention relates to a process for the preparation of solid polyamines stabilized by a polyadduct coating with retarded reactivity, characterized by reacting solid, finely divided polyamines with water-insoluble, bifunctional and / or polyfunctional (cyclo) aliphatic, araliphatic and / or aromatic polyisocyanates in an amount of 0.01 to 25 equivalent% of NCO per equivalent of amine, in a liquid medium of di- and / or polyfunctional polyols and / or plasticizers and / or water (optionally in the presence of non-polar or slightly polar solvents), to a suspension of polyadduct-coated, stabilized polyamines with delayed reactivity in the liquid medium. If appropriate, the stabilized polyamines can be isolated from the liquid medium, for example by filtration. Isolated, stabilized polyamines can then be subsequently suspended in prepolymers containing polyols and / or polyamines or NCO groups, to give PU reactive systems with an extended pot life and increased storage stability.

The subject of the invention are also polyadduct-coated polyamines by the above process in finely divided form, preferably suspended in liquid or low-melting high-molecular polyhydroxyl compounds and / or higher molecular weight polyamino compounds and / or NCO prepolymers, the solid, suspended polyamines having a 0.01 to 25 equivalent % implementation of the NH₂- Groups have been subjected to polyisocyanates and the polyadduct-coated polyamines show a higher crosslinking temperature or slower reaction with polyisocyanates than the unstabilized polyamines.

Another object of the invention is the use of the stabilized polyadduct-coated polyamines, preferably suspended in plasticizers and / or higher molecular weight, low-melting polyhydroxyl compounds and / or higher molecular weight polyamines, as the reaction component which has isocyanate-reactive hydrogens, in polyurethane-forming reactive systems, optionally with the use of low molecular weight aromatic and / or (cyclo) aliphatic polyamines and / or polyols, optionally catalysts, customary auxiliaries or additives, together with (preferably higher molecular weight) polyisocyanate (prepolymer) s for the production of polyurethanes. They are used in particular as a reaction component with reactive hydrogen atoms in curable polyurethane reactive systems that are stable in long-term storage, the stabilized polyamines or their suspensions preferably being mixed with NCO prepolymers to form storage-stable, heat-curable one-component reactive systems.

The production of polyurethane urea elastomers from polyisocyanates, higher molecular weight polyhydroxy compounds and aromatic diamines is known. In order to ensure adequate processing times for reactive systems from the starting components mentioned, the technically most frequently used reactive aromatic isocyanates are expediently reacted with slow-reacting diamines. In this context, especially those aromatic diamines whose basicity and thus reactivity to isocyanates is reduced have proven themselves as diamines in practice. This reduction in reactivity can be achieved by introducing suitable, nucleophilicity-reducing or sterically active, "bulky" substituents. Examples of such substituents are, for example, halogen: for example 3.3^1-Dichloro-4,4'-diaminodiphenylmethane (MOCA) or 3,5-diamino-4-chloro-l-alkylbenzene [DE-OS 2 065 8697, carboxylic acid ester: 3,5-diamino-4-chloro-benzoic acid alkyl ester (DE-OS 2 003 706) or 4,4'-diamino-3,3'-carbethoxy-diphenylmethane [FR-PS 2 104 4427, sulfonic acid amides: 3,5-diamino-4-alkyl-benzenesulfonic acid dibutylamide [EP-A 0 037 0927, p , SS or SRS: 2,2'-diaminodiphenyl disulfide (DE-OS 2 435 872), 1,2-bis (2-aminophenylmercapto) ethane (US Pat. No. 3,920,617), alkyl groups: 4,4^1-Diamino-3,3'-5,5'-tetramethyl-diphenylmethane (DE-OS 2 731 815) or 3,5-diethyl-2,4-diamino-toluene (DETDA).

All of these aromatic chain extenders, however, have only a limited, relatively short casting and pot life in combination with NCO group-containing polyethers or polyesters. They must be processed very quickly, especially in the heat. In many cases, however, the structures of the hard segments formed with the isocyanates are "disturbed" by the substituents required to reduce the amine reactivity, and the reduced amine reactivity necessarily means that the properties of the polyurethanes have deteriorated.

US Pat. No. 3,891,606 describes the crosslinking of NCO prepolymers from polyhydroxyl compounds and an excess of polyisocyanates with aromatic diamines, the reactivity of which to isocyanate groups is reduced by complex formation with certain alkali metal salts. The disadvantage of this process is that it is limited to two special aromatic diamines. In addition, the complex between the aromatic diamine and the alkali metal salt must be prepared in a separate process step.

Little is known about the production of polyurethane ureas by reacting higher molecular weight polyisocyanates with aromatic diamines in the heterogeneous phase.

The subject of DAS 1 122 699 is a process for the production of polyurethane elastomers by crosslinking liquid isocyanate prepolymers by reaction with mixtures of primary diamines and compounds having multiple hydroxyl groups with shaping, in which a dispersion of a powdery crystalline diamine in a liquid having multiple hydroxyl groups Polyester, Polyether or in castor oil is introduced into the prepolymer at a temperature below the melting point of the diamine and the composition is cured at temperatures above the melting point of the diamine in the mixture in a manner known per se.

Furthermore, US Pat. No. 3,105,062 describes a process for the production of polyurethane ureas. Here, an aromatic diamine in the form of a finely ground powder is added to a higher molecular weight, NCO group-containing polyether or polyester. This reaction mixture, which is initially in the form of a two-phase system, then only changes into a reaction melt in the course of solidification at elevated temperature, but, in the absence of thorough mixing, heterogeneous products of inhomogeneous composition are often obtained.

The actual "amine crosslinking" takes place in accordance with the process according to DAS 1 122 699 and US 3 105 062 in the liquid phase at appropriate temperatures. A particular disadvantage of the process are the diamines which melt during processing, such as 1,5-naphthylenediamine (mp. = 189 ° C.) or 4,4'-diaminodiphenyl ether (mp. = 186 ° C), the high temperatures required for liquefaction, since experience has shown that decomposition reactions in the polyurethane occur to a considerable extent, which change the mechanical properties of the process products in an uncontrollable manner. In addition, the storage stability of these heterogeneous reaction mixtures at room temperature is very limited and is only up to several hours. Depending on the choice of the aromatic diamine and in particular the higher molecular weight polyisocyanate (NCO prepolymer based on polyether or polyester), there is an ever increasing viscosity increase with the formation of paste or up to the solid phase which can no longer be processed.

Encapsulation of amines is known per se, for example from US Pat. Nos. 3,396,116 and 3,396,117, where the capsule wall consists of water-soluble alginates, optionally combined with other polymers such as polyvinyl alcohol, polyethylene oxides, polyacrylates or gelatin, which may be post-cured .

According to US Pat. No. 3,384,680, liquid polyamines are bound to finely divided, absorbent materials, then sealed and used for epoxy formulations.

According to US Pat. No. 3,791,980, electrically conductive amines, for example diethylamine, are sprayed under high voltage through nozzles to form charged, round droplets and coated with liquid, meltable material.

DE-OS 3 224 456 describes a microencapsulation of water-insoluble, liquid polyamines, optionally in the presence of water-soluble protective colloids, with water-soluble bisulfite adducts of polyisocyanates in aqueous solution, and the use of such microencapsulated, liquid polyamines in the production of polyurethane resin formulations.

DE-OS 3 224 454 describes the microencapsulation of water-insoluble substances (for example coloring components for carbonless reaction papers) by encapsulation using polyureas from liquid polyamines and water-soluble polyisocyanate derivatives in aqueous solution, if appropriate in the presence of protective colloids (cf. also US Pat. No. 3,575 882, 3 575 515, 3 607 776, 4 076 774 and DE-OS 2 655 048).

Finally, in the Soviet Union. No. 53 52 89 describes a process for the production of encapsulated aromatic diamines which consists in that the corresponding aromatic diamine is subjected to an interaction with excess amounts of diisocyanate in the presence of a hexane / ethyl acetate mixture = 6: 1. The reaction is carried out at room temperature.

These "encapsulated diamines" have been claimed as hardeners for epoxy resins. However, it is not evident from this patent literature to what extent the reactivity of these polyamines, which have been modified in a special solvent mixture, and which also have to be isolated therefrom, is lowered towards isocyanate groups.

In contrast, according to the invention, solid polyamines with a retarded reactivity, preferably directly, which are formed by reaction of the solid polyamines with two and / or multifunctional, low and / or higher molecular weight compounds with aliphatic and / or aromatically bound isocyanate groups and stabilized by means of coating with polyisocyanate addition products (polyadducts) in a higher molecular weight polyhydroxyl compound and / or a plasticizer, the sheath essentially consisting of polyadducts (polyureas) in a thin layer and in only a minor reaction of the NH₂-Groups on the surface of the solid polyamines (for example 0.1 to 25% of the amine groups) is formed. The stabilization reaction by means of a polyadduct coating gives polyamine particles which are only above a "thickening temperature" to be defined in more detail, for example by cracking open the polyadduct sheath, by destroying the sheath by shear forces, facilitating diffusion of the polyamines through the polyadduct layer or even dissolving the polyadduct layer by the action of polar solvents, to react with other polyisocyanates in polyurethane reactive systems.

The stabilized polyamines are preferably prepared by reacting the finely divided polyamines in higher and optionally low molecular weight compounds containing OH groups and / or in plasticizers, optionally with the addition of organic solvents. It is less practical to filter the stabilized, coated polyamines formed by filtration, e.g. separate from the plasticizers, isolate and only then suspend in low or high molecular weight polyhydroxy compounds and / or higher molecular weight polyamines and / or NCO prepolymers. Any organic solvents that may be used can be removed again by distillation (in vacuo) if the temperature is not too high (below the thickening temperature).

The stabilized polyamines still contain at least 75%, preferably more than 85%, in particular more than 90%, but at most 99.9%, preferably at most 99.8%, in particular at most 99.5% of the originally present (primary and / or secondary) ) Amino groups of the unmodified polyamines.

When mixed with NCO prepolymers, the stabilized polyamines have a considerably reduced reaction rate or a significantly increased storage stability compared to mixtures with unstabilized, solid polyamines. These long-term storage-stable reactive mixtures can be cured by simple heating, a rapid polyaddition reaction taking place above a certain temperature (“thickening temperature”). This "thickening temperature" can be varied and a high storage stability can also be set at higher storage temperatures by a simple variation of the reaction conditions, for example temperature in the coating reaction, selection of the reaction medium or type and amount of the isocyanate stabilizers used for the stabilization. The optimal stabilization conditions under formation of the solid, polyadduct-coated polyamines can be determined for the respective PU reactive mixtures (one-component PU mixtures) by simple series tests.

The long-term storage-stable, easily flowable, possibly easily meltable, heterogeneous PUR reactive systems formed with the stabilized polyamines can also be cured by adding polar solvents (e.g. dimethylformamide); in some cases, the action of strong shear forces is sufficient, but it is this is a less widely applicable form of polyurethane formation. However, heat curing is preferred, in which the long-term storage-resistant PUR reactive systems according to the invention can be reacted even in a relatively low temperature range (above the thickening temperature, preferably 55 55 ° C, particularly preferably at 100 to 140 ° C), high-quality polyurethane ( urea) elastomers, coatings, laminates, bonds or cellular elastomers can be produced.

The invention thus relates to a process for the preparation of solid polyamines stabilized by a polyadduct coating with retarded reactivity, characterized in that solid polyamines having at least two primary and / or secondary amino groups, preferably diprimary diamines, in particular aromatic diamines, with melting points> 50 ° C, preferably> 80 ° C, in finely divided form, for example with a particle size of 0.5 to 200 microns, preferably 1 to 50 microns, with water-insoluble, di- or higher-functional, low and / or higher molecular weight polyisocyanates with aliphatic and / or aromatically bound isocyanate groups as stabilizers in an amount of 0.1 to 25 equivalent% NCO per primary or secondary amino group of the polyamine, preferably 0.2 to 15 equivalent%, in particular 0.5 to 10 X equivalent%, in a liquid medium composed of low and / or higher molecular weight polyhydroxyl compounds (preferably higher molecular weight polyhydroxyl compounds with molecular weights of 400 to 10,000), and / or plasticizers, optionally in the presence of non-polar or slightly polar solvents, preferably based on aliphatic, cycloaliphatic or aromatic hydrocarbons, halohydrocarbons, ethers, ketones or esters, at temperatures below the melting temperature of the polyamines, preferably up to about 70 ° C., particularly preferably at 0 to 50 ° C., to form a suspension of polyadduct-coated, stabilized polyamines in the liquid medium, and optionally removing the solvents used, or isolating the stabilized polyamines and isolating the isolated, Stabilized polyamines suspended in preferably higher molecular weight polyhydroxyl compounds and / or higher molecular weight polyamino compounds.

The invention furthermore relates to a partially surface reaction with water-insoluble, di- and / or higher-functional polyisocyanates, preferably more than 2,1-functional polyisocyanates, polyadduct-coated, stabilized, solid, finely divided polyamines of retarded reactivity with an amino group residual content of at least 75%, preferably at least 85% and in particular at least 90% and less than 99.9%, preferably less than 99.8% and in particular less than 99.5% of the amino groups originally present, suspended in higher molecular weight polyhydroxy compounds with molecular weights from 400 to 10,000, preferably 500 to 6000, and / or higher molecular weight polyamino compounds with molecular weights from 400 to 10,000, preferably 500 to 6000 and aromatic amino groups, and / or plasticizers, wherein the suspension optionally contains further low and / or higher molecular weight polyhydroxyl compounds and / or non-stabilized low and / or higher molecular weight polyamino compounds.

The suspensions are preferably produced by the process described. The further low and / or higher molecular weight polyols and / or polyamines are admixed in particular after the stabilization reaction of the solid polyamines has been carried out with the insufficient amounts of polyisocyanates.

The subject of the invention is also the use of polyadduct-coated, stabilized, solid polyamines with retarded reactivity, in accordance with the disclosed production processes and compositions, in particular in the form of PU one-component reactive mixtures, for the production of polyurethanes (polyurethane ureas).

The slow-reacting polyamines allow both polyurethane production, in which the reaction time (pot life) is extended (e.g. with casting systems), but they also allow the construction of (one-component) PU reactive systems that are stable in long-term storage at low temperatures, which can only be caused by the effect of temperature or the addition of polar solvents are reacted. One-component PU reactive systems are understood to mean mixtures which already contain the reactive components in amounts such that the desired polymeric polyurethane (urea) is formed directly by "curing", for example heat curing.

If stabilized polyamines are only partially used in addition to non-stabilized polyamines, then a step-by-step build-up of polyurethanes (ureas) can also be achieved, since then the non-stabilized polyamines first react with a clear viscosity and polymer build-up and only then - if necessary in another or application or use stage, the stabilized polyamines, for example at elevated temperature, the reaction to the now highly polymeric polyurethane (urea). The higher molecular weight polyamines are preferably used as non-stabilized polyamines; However, proportions of low molecular weight, preferably aromatic di- or polyamines can also be used.

The subject of the invention is therefore in particular the use of the polyadduct-coated, stabilized, solid polyamines with retarded reactivity, optionally suspended in low and / or higher molecular weight polyhydroxyl compounds, higher molecular weight polyamines and / or plasticizers according to the disclosed production processes and compositions, for the production of polyurethane (urea) out<ul id="ul0001" list-style="none"><li>A) low and / or higher molecular weight compounds bearing H groups reactive toward isocyanate,</li><li>B) low and / or higher molecular weight polyisocyanates and / or NCO prepolymers, it being possible for the isocyanates to be wholly or partly also in blocked form,</li><li>C) optionally polyurethane catalysts and</li><li>D) if appropriate customary auxiliaries and / or additives and / or monofunctional chain terminators,</li></ul>wherein the NCO groups from B) and the reactive H groups from A) are used in equivalence ratios of A: B of 1.5: 1 to 0.8: 1, preferably 1.25: 1 to 0.9: 1 become, characterized in that one as A) polyadduct-coated, stabilized, solid polyamines with retarded reactivity, suspended in low and / or higher molecular weight polyhydroxyl compounds (preferably higher molecular weight polyhydroxyl compounds with a molecular weight of 500 to 6000), and / or higher molecular weight polyamines and / or plasticizers, the suspension optionally additionally comprising low molecular weight, di- or polyfunctional chain extenders or crosslinking agents, preferably di- and / or polyols of molecular weight 62 to 399 and / or low molecular weight di- and / or polyamines (molecular weight 32 , 60 to 399), can be used

and converting the curable, flowable or easily meltable, preferably long-term stable PU reactive systems by heat, shear forces and / or polar solvents into solid or foamed PU plastics, coatings or coatings.

If higher molecular weight polyamines are used as the suspending medium, they are not used from the outset as a suspending medium for the solid polyamines, but only subsequently added to the stabilized polyamine suspensions in (higher molecular weight) polyols and / or plasticizers or as the sole suspending medium for beforehand (e.g. through Filtration) uses isolated, stabilized polyamines.

A preferred embodiment is also that, for example suspending polyamines suspended in higher molecular weight polyols stabilized by polyadduct coating in higher molecular weight NCO prepolymers, the amount of reactive hydrogen atoms and that of the NCO groups being chosen in this way, for example in equivalent ratios of 1.25: 1 to 0.8: 1, that high molecular weight polyurethane (urea) s form when these (storage-stable) one-component mixtures are brought to full conversion by heating.

I.) Starting materials for the stabilized polyamine suspensions A) according to the invention and their preparation

Suitable starting components for the preparation of the solid polyamines stabilized according to the invention are all di- or more than difunctional polyamines or any mixtures thereof which have at least two primary and / or secondary amino groups, provided that they have a melting point above 50 ° C., preferably&gt; 80 ° C. These can be aliphatic, cycloaliphatic, araliphatic, but preferably aromatic and heterocyclic polyamines (the claimed amines are referred to briefly as polyamines in the present application). Examples of such compounds, preferably diamines, are listed in the following list, together with their melting points:<tables id="tabl0001" num="0001"><img file="EP0171015A2_D0001.tif" /></tables><tables id="tabl0002" num="0002"><img file="EP0171015A2_D0002.tif" /></tables><tables id="tabl0003" num="0003"><img file="EP0171015A2_D0003.tif" /></tables>The solid, finely divided polyamines suitable for the stabilization reaction may only dissolve to a small extent, for example L 3%, preferably &lt;1%, in the polyhydroxyl compounds, plasticizers and, if appropriate, solvents used for the stabilization reaction of the polyamines. After carrying out the stabilization reaction with polyisocyanates, the stabilized polyamine particles covered on the surface with polyureas are considerably less soluble and have higher softening temperatures.

In order to stabilize the solid, finely divided polyamines, in undersized amounts (at least 0.1, preferably at least 0.2 and in particular at least 0.5; at most up to 25, preferably up to 15, preferably up to 10 equivalent%, based on the amino groups of the polyamines), water-insoluble, liquid, if appropriate also solidified [or resinous, but then present in dissolved form di- and / or polyisocyanates, in particular higher-functional polyisocyanates an average NCO functionality of&gt; 2.1, preferably&gt; 2.5. Biuretized, dimerized, trimerized, allophanated or carbodiimidized or polyisocyanates modified with polyols, in particular (cyclo) aliphatic or araliphatic, di- and / or in particular higher-functionality polyisocyanates are preferred. Mixtures of the polyisocyanates mentioned can also be used. The polyisocyanates or their modification products generally have average molecular weights of up to 850, preferably up to 750, in particular up to 550, and preferably average molecular weights of at least 168.

Examples are hexamethylene diisocyanate, undecamethylene diisocyanate, dodecamethylene diisocyanate, lysine methyl ester diisocyanate, menthane diisocyanate, isophorone diisocyanate, cyclohexane diisocyanate, α, α, α ', α'-tetramethyl-m / p-hexahydroxylylene diisocyanate, 4-isocyanyl diisocyanate, 4-isocyanyl diatomate, 4-isocyanyl diisocyanate, 4-isocyanyl diisocyanate, 4-isocyanyl diisocyanate, 4-isocyanyl diisocyanate, Dicyclohexylmethane diisocyanates, 1,6,11-triisocyanatoundecane, substituted 1,5-diisocyanatopentane derivatives according to EP-A 77 105 (e.g. 1-methyl-1,5-pentane diisocyanate) or their oligomeric derivatives (for example in accordance with EP-A 77 104) m / p xylylene diisocyanate or α, α ', α'-tetramethylxylylene diisocyanates (m or p isomers). Polyisocyanates with an NCO functionality of more than two (in particular_P,2.1), for example biuretized, dimerized, carbodiimidized, allophanized, trimerized or polyol-modified polyisocyanates, for example based on the abovementioned diisocyanates, in particular based on hexamethylene diisocyanate, isophorone diisocyanate or dicyclohexylmethane diisocyanate, and also tolylene diisocyanates.

Aromatic, low molecular weight diisocyanates, for example tolylene diisocyanates or diphenylmethane diisocyanates, are often less favorable, but it is better to use the higher molecular weight, aromatic polyisocyanates with NCO functionalities 2.1, which are NCO prepolymers of more than bifunctional polyols (mixtures) and the diisocyanates mentioned , or also trimer of the diisocyanates mentioned or Mixed trimers of tolylene diisocyanates or diphenylmethane diisocyanates and aliphatic diisocyanates such as hexane diisocyanate, dicyclohexylmethane diisocyanates or isophorone diisocyanate. Diisocyanates with long-chain alkyl substituents, for example C12-C18-alkyl-2,4-benzenediisocyanate, are also suitable.

The surface reaction of the solid polyamines with the polyisocyanates used for stabilization takes place in a liquid medium which is not a (good) solvent for the solid polyamines. Suitable plasticizers are, for example, plasticizers such as dialkyl adipate or trialkyl phosphates, in particular less polar, long-chain trialkyl esters such as stearyl esters. In this case, proportions of volatile, less polar solvents (e.g. aliphatic hydrocarbons) are also used and, if appropriate, are removed again after the covering or after the coating reaction which has taken place on the surface.

However, the stabilization reaction is preferably carried out directly in the higher molecular weight polyols, the suspension or paste obtained then generally being used without separating off the suspension medium. Suspensions with a weight ratio of stabilized, solid polyamine to suspension medium of 20:80 to 80:20, in particular 40:60 to 60:40, are preferred.

Those polyols which are also used for the production of the NCO-functional prepolymers and which are described in detail as polyol components for the production of NCO prepolymers can be used for the suspension.

Since the higher molecular weight polyols serve as a suspending medium for the solid, finely suspended polyamines and compete with the polyamines in the reaction with the stabilizer polyisocyanates, they should be liquid as possible at room temperature (or at temperatures of L 60⁰ melting) and low viscosity, have as little solvent as possible on the suspended polyamines and differ as strongly as possible from the amine reactivity in their OH group reactivity. For these reasons, polyols with secondary OH groups, for example polyoxypropylene polyols, are generally preferred. The less reactive the amines, the more preferred are the polyols which predominantly carry secondary OH groups, since these secondary OH groups react more slowly with isocyanates.

In the case of solid, aliphatic, cycloaliphatic or araliphatic polyamines, the reactivity of the amino group is so much greater than that of OH groups that it is practically irrelevant whether the polyols carry primary or secondary OH groups.

In the case of aromatic polyamines, the difference in reactivity is NH₂/ OH lower, therefore polyols are preferred there which at least partially carry secondary OH groups. If the aromatic polyamines are still less reactive than unsubstituted diamines through appropriate substitution, polyols containing secondary hydroxyl groups are predominantly preferred.

In practically all cases, however, it is possible to use both polyols with primary and secondary OH groups as the suspending medium. With smaller differences in reactivity, however, hydroxyl groups then increasingly take part in the reaction with the polyisocyanates and, in addition to the stabilization reaction while covering the diamines, polyols are optionally linked to one another with an increase in viscosity or occasionally attached to the diamine particles via the polyisocyanates. These reactions could also explain the improved sedimentation stability of such suspensions, which was surprisingly observed after the stabilization reaction in polyols.

Preferred, higher molecular weight polyols are polyether and polyester polyols, in particular polyether polyols such as polyoxypropylene polols or polyoxyethylene / oxypropylene polyols with preferably secondary OH groups.

In the stabilization reaction or subsequently, low-molecular polyols (molecular weights 62-399) can also be added to the stabilized diamine suspension. These low molecular weight polyols then act as chain extenders in the conversion to the high polymer polyurethane plastics. However, since the desired improved properties of the polyurethanes are often obtained by using the di- or polyfunctional amines, generally less than 80% of the amine equivalents, preferably less than 50%, should be replaced by OH groups from low molecular weight polyols; this applies both in suspension A) and for the overall reactive system for polyurethane production. To carry out the stabilization reaction, the solid polyamine is reacted with a suitable stabilizing polyisocyanate in the suspension medium. The polyamine can first be suspended in the medium and then the polyisocyanate can be mixed in, or the polyisocyanate is first finely divided or dissolved in the suspension medium and then the solid polyamine is suspended.

The "isocyanate stabilizers" are used in an amount of 0.1 to 25 equivalent% NCO per equivalent of NH₂ used in polyamine, preferably 0.2 to 15 equivalent%, in particular 0.5 to 10 equivalent%.

The polyurea coating can also be used with even higher proportions, for example 30 equivalent% NCO per NH₂, are carried out, but such high conversions mostly reduce the proportions of the reactive amino groups when using the stabilized polyamines in PUR reactive systems and make them impractical.

Temperatures below the respective melting points of the polyamine are chosen as the temperature of the coating reactions. They are generally below 70 ° C, preferably 0 to 50 ° C.

In the reactive systems according to the invention with the use of the stabilized polyamines, on the one hand there is a demand for a pot life as long as possible (pouring and processing time) at room temperature or slightly elevated temperatures, for example 50-70 ° C., and on the other hand the rapid networking of the reactive systems at elevated temperatures eg above 100 ° C. The conditions imposed by practice can be largely controlled by the chemical constitution of the aliphatic or aromatic "isocyanate" stabilizers for the diamines. If a certain limit amount of stabilizer is exceeded, then under normal heating conditions (110-140 ° C) only unsatisfactory crosslinking occurs. It is therefore advisable to determine the optimum amount of the respective isocyanate stabilizer for the desired formulation, in which case the curing temperature or curing time are determined if the reactive systems have a sufficient processing time at room temperature or moderately elevated temperature. In general, the stabilizing effect of low molecular weight, aromatic diisocyanates is less than that of aliphatic diisocyanates. The stabilizing effect increases with increasing functionality of the isocyanates. Triisocyanates are generally more effective than diisocyanates. The stabilizing effect generally also increases with the amount of stabilizers.

It is preferred to carry out the "stabilization reaction" of the polyamines directly in a medium which, after the reaction, is further suitable as a reaction component in the reactive systems for the construction of high molecular weight polyurethanes (urea). Polyols are therefore preferred as the reaction medium. For certain applications, for example in the coating sector, plasticizers can also be used alone or in part as a medium. Volatile solvents, which, however, do not noticeably dissolve the polyamines, can also be used, but this is very little desirable for technical reasons, since they have to be removed in an additional step.

A stabilization reaction of the polyamines with the water-insoluble polyisocyanates can also take place in water as a medium if the polyamines do not dissolve significantly therein. To this end, the water-insoluble polyisocyanates can be added in the form of solutions in water-miscible solvents (for example tetrahydrofuran or dioxane) or in water-immiscible, inert solutions, for example ethyl acetate or toluene. After the surface modification, the stabilized polyamines can then be suctioned off and (carefully) dried. However, sufficiently large amounts of water remain bound in / on the particles, so that when they are used in PU reactive systems there is usually also a water / NCO reaction which mostly leads to the formation of bubbles. Such stabilized polyamines can therefore (practically only) be used practically for foamed or cellular polyurethane plastics.

In principle, it is also possible to isolate the stabilized polyamine particles, for example from plasticizers or polyols, (for example by filtration). The isolated particles can then be suspended in other polyols or also in higher molecular weight polyamines. This process is of course cumbersome and less preferred, but it can be advantageous under certain circumstances if suspensions of stabilized polyamines of a certain type are to be obtained which, under certain circumstances, cannot be built up directly in the suspending media, for example in higher molecular weight polyamines as the direct suspending medium.

II) Use of the stabilized polyamine suspensions in polyurethane reactive systems

The stabilized polyamine suspensions are used as components A) for the production of polyurethanes as compounds bearing H atoms which are reactive toward isocyanates. Compared to the isocyanate or NCO prepolymer component B), they can be used alone if they already contain all the desired components with reactive H atoms in the stoichiometrically desired amount.

If appropriate, however, other compounds with reactive hydrogen atoms, for example further higher molecular weight di- or multifunctional polyols, higher molecular weight di- or multi-functional polyamines (including the -hydrazides), and optionally further low molecular weight di- or multi-functional compounds with reactive hydrogen atoms, for example Polyols, polyamines, polyamino alcohols, polyhydrazide compounds and the like, compounds known as chain extenders or crosslinking agents are used in addition to the stabilized polyamine suspensions.

Suitable isocyanate components B), which can be used as low molecular weight di- or polyfunctional isocyanates or for the preparation of the low or high molecular weight, isocyanate group-containing prepolymers, are aliphatic, cycloaliphatic, araliphatic, aromatic and / or heterocyclic polyisocyanates as they come from a Numerous publications are known for use in the construction o f polyurethane and for example by W. Siefken in Justus Liebigs Annalen der Chemie 562, pages 75 to 136, 1949, and for example in DE-OS 2 854 384 and 2 920 501. Examples are: Ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3- and -1,4-diisocyanate and any mixtures of these isomers, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane, 2,4- and 2,6-hexahydrotoluenediisocynate as well as any mixtures of these isomers, hexahydro-1,3- and / or -1 , 4-phenylene diisocyanate, perhydro-2,4'- and / or -4,4'-diphenylmethane diisocyanate, 1,3- and 1,4-phenylene diisocyanate, 2,4- and 2,6-tolylene diisocyanates and any mixtures of these isomers, diphenylmethane-2,4'- and / or 4,4'-diisocyanates, naphthylene-1,5-diisocyanates, triphenylmethane-4,4 ', 4 "triisocyanates, polyphenyl polymethylene polyisocyanates, as obtained by aniline-formaldehyde condensation and subsequent phosgenation and described, for example, in British Patents 874,430 and 848,671, perchlorinated aryl polyisocyanates, as described, for example are described in DE-AS 1 157 601, polyisocyanates containing carbodiimide groups, as described in DE-PS 1 092 007, diisocyanates, as described in US Pat. No. 3,492,330, polyisocyanates containing allophanate groups, such as, for example in GB-PS 994 890, BE-PS 761 626 and published Dutch patent application 7 102 524, polyisocyanates containing isocyanurate groups, such as those described, for example in the DE-PS 1 022 789, 1 222 067 and 1 027 394 and in the DE-OSs 1 929 034 and 2 004 048, polyisocyanates containing urethane groups, as described for example in BE-PS 752 261 or in the US -PS 3,394,164 are described, acylated urea group-containing polyisocyanates according to DE-PS 1 230 778, biuret group-containing polyisocyanates such as, for example in DE-PS 1 101 394, in GB-PS 889 050 and in FR-PS 7 017 514 are described, polyisocyanates prepared by telomerization reactions, as described for example in BE-PS 723 640, polyisocyanates containing ester groups, as mentioned for example in GB-PS 965 474 and 1 072 956, in US-PS 3 567 763 and in DE-PS 1 231 688, as well as reaction products of the above-mentioned isocyanates with acetals according to DE-PS 1 072 385 . It is also possible to use any mixtures of these polyisocyanates.

The technically easily accessible polyisocyanates, for example, are generally particularly preferred 2,4- and 2,6-tolylene diisocyanate and any mixtures of these isomers ("TDI"), polyphenyl-polymethylene polyisocyanates, such as those produced by aniline-formaldehyde condensation and subsequent phosgenation ("crude MDI"), 4, Polyisocyanates containing 4'- and / or 2,4'-diphenylmethane-4,4'-diisocyanate and carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, urea groups or biuret groups ("modified polyisocyanates").

The polyisocyanates or the isocyanate prepolymers prepared from the polyisocyanates mentioned and the above-mentioned higher and / or lower molecular weight polyols are said to be in liquid form in the reaction with the finely divided, suspended aromatic diamine.

The production of the NCO prepolymers is known in principle and is described, for example, in DE-OS 2 854 384 and 2 920 501. The polyisocyanates or the NCO prepolymers can also be used in the form of their form "partially" or "completely" blocked on the NCO groups with conventional blocking agents (such as ketoximes, lactams, malonic esters, phenols).

The polyisocyanates can also be used in a stabilized form with retarded reactivity, in accordance with the processes according to DE-OS 3 112 054, 3 228 723, 3 228 724, 3 228 670 and 3 230 757 and EP-A 2 230 757 .

Depending on the application, the NCO prepolymers are essentially linear (eg when used with elastomers) or branched (eg for coatings, coatings, paints or foams). The content of free (or blocked) NCO groups is generally between 0.5 and 20% NCO, but can be even higher, for example up to 25% NCO. The NCO content determines, for example, the "hardness" of the PU plastics. For elastomers it is generally between 1 and 12%, preferably 1.5 to 7.5%.

As starting components for the preparation of the low and / or higher molecular weight isocyanate pre-adducts B), or Higher molecular weight, di- or polyfunctional polyhydroxyl compounds with a molecular weight of approximately 400 to 10,000, preferably 500 to 6000 and melting points 460'C, are suitable as suspension medium and also, if appropriate, additional reaction component with H atoms which are reactive towards NCO in the PU reactive systems. These are at least two, preferably 2 to 4, hydroxyl-containing polyesters, polyethers, polythioethers, polyacetals, Polycarbonates and polyester amides as are known per se for the production of homogeneous and cellular polyurethanes. Examples of this are detailed, for example, in DE-OS 2 920 501 and DE-OS 2 854 384.

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, polycarboxylic acid anhydrides or polycarboxylic acid esters of lower alcohols. The polycarboxylic acids can be aliphatic, cycloaliphatic, aromatic and / or heterocyclic in nature and optionally, for example by halogen atoms, substituted and / or unsaturated. Examples include: Succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, trimellitic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylenetetrahydrophthalic anhydride, glutaric anhydride, maleic acid, maleic anhydride, fumaric acid, oleic acid, dimeric and trimeric fatty acids, optionally in admixture with monomeric fatty acids, terephthalic acid dimethyl ester and Terephthalic acid bis-glycol ester. As polyhydric alcohols come, for example Ethylene glycol, propanediol- (1,2) and - (1,3), butanediol- (1,4) and - (2,3), hexanediol- (1,6), octanediol- (1,8), neopentylglycol, 1,4-bis-hydroxymethylcyclohexane, 2-methyl-1,3-propanediol, glycerol, trimethylolpropane, hexanetriol (1,2,6), butanetriol (1,2,4), trimethylolethane, pentaerythritol, quinite, mannitol and Sorbitol, 1,4,3,6-dianhydrohexite, methyl glycoside, also di-, tri-, tetra- and polyethylene glycol, di-, tri-, tetra- and polypropylene glycol, di-, tri-, tetra- and polybutylene glycol in question. The polyesters can have a proportion of terminal carboxyl groups. Polyesters of lactones, for example ai-caprolactone or hydroxycarboxylic acids, for example ω-hydroxycaproic acid, can also be used.

The at least two, usually two to eight, preferably two to three, hydroxyl-containing polyethers which are possible according to the invention are also of the type known per se and are, for example, obtained by polymerizing tetrahydrofuran and / or epoxides such as ethylene oxide, propylene oxide, butylene oxide, Styrene oxide or epichlorohydrin with itself, for example in the presence of BF₃, or by addition of these epoxides, optionally in a mixture or in succession, to starting components with reactive hydrogen atoms such as water, alcohols, amino alcohols, amines, sugar and other known starting components, for example ethylene glycol, propanediol- (1,3) or - (1,2), Trimethylolpropane, 4,4'-dihydroxydiphenylpropane, aniline, ammonia, ethanolamine or ethylenediamine. Also sucrose polyether, such as described in DE-AS 1 176 358 and 1 064 938 are possible according to the invention. Examples are higher molecular weight polyoxyalkylene polyols, for example polyoxytetramethylene glycols or ethoxylation and / or propoxylation products of low molecular weight diols and polyols or mono-, di- and polyamines, for example propoxylated trimethylolpropane, propoxylated ethylenediamine or linear or branched polypropylene glycol ethers, which may contain ethylene oxide in statistical, block or terminal form and have a total molecular weight of 400 to 10,000, preferably 600 to 6000. Also modified by vinyl polymers, such as, for example by polymerization of styrene and acrylonitrile in the presence of polyethers (US Pat. Nos. 3,383,351, 3,304,273, 3,523,093, 3,110,695, DE-PS 1,152,536) are suitable, as are OH-containing polybutadienes. Polyethers with secondary OH groups are preferred as the suspending medium.

Among the polythioethers, the condensation products of thiodiglycol with themselves and / or with other glycols, dicarboxylic acids, formaldehyde, aminocarboxylic acids or amino alcohols should be mentioned in particular.

Examples of suitable polyacetals are the compounds which can be prepared from glycols, such as diethylene glycol, triethylene glycol, 4,4'-dioxethoxydiphenyldimethylmethane, hexanediol and formaldehyde. Polyacetals suitable according to the invention can also be prepared by polymerizing cyclic acetals.

Suitable polycarbonates containing hydroxyl groups are those of the type known per se, which can be obtained, for example, by reacting diols such as propanediol (1,3), butanediol (1,4) and / or hexanediol (1,6), di- , Tri- or tetraethylene glycol with diaryl carbonates, for example diphenyl carbonate, or with phosgene.

The polyester amides and polyamides include, for example, 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 and optionally modified natural polyols, such as castor oil, carbohydrates or starch, can also be used. Addition products of alkylene oxides with phenol-formaldehyde resins or with urea-formaldehyde resins can also be used in the process according to the invention.

Polybutadienes having hydroxyl end groups are also suitable according to the invention, since they result in particularly elastic and hydrolysis-stable products. If appropriate, it is also possible to use polyhydroxyl compounds which contain high molecular weight polyadducts or polycondensates or polymers in finely dispersed or else dissolved form.

Polyhydroxy compounds containing polyadduct are obtained if polyaddition reactions (for example reactions between polyisocyanates and amino-functional compounds) or polycondensation reactions (for example between formaldehyde and phenols and / or amines) are carried out in situ in the abovementioned compounds containing hydroxyl groups.

Polyhydroxyl compounds modified by vinyl polymers, as obtained, for example, by polymerizing styrene and acrylonitrile in the presence of polyethers or polycarbonate polyols, are also suitable for the process according to the invention.

Representatives of these compounds to be used according to the invention are, for example, in High Polymers, Vol. XVI, "Polyurethanes, Chemistry and Technology", written by Saunders-Frisch, Interscience Publishers, New York, London, Volume I, 1962, pages 32-42 and pages 44 and 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, and in DE-OS 2 854 384 and 2 920 501.

Suitable polyols are also hydroxyl-containing polymers, for example copolymers of olefinically unsaturated monomers and olefinically unsaturated monomers with active hydrogen. They are described, for example, in EP-A 62 780, page 5 and their examples. They are preferably used for sealing, filling, adhesive or underbody protection compounds. Mixtures of the abovementioned compounds with at least two hydrogen atoms which are reactive toward isocyanates and have a molecular weight of 400-10,000, for example mixtures of polyethers and polyesters, can of course be used.

Low molecular weight (T 60 ° C.), higher molecular weight polyamines with aromatic and / or aliphatic amino groups and molecular weights of 400 to 10,000, preferably 500 to 6000, can also be used as higher molecular weight suspending agents and / or additional higher molecular compounds with H atoms reactive towards NCO.

The higher molecular weight polyamino compounds with aromatic amino groups with a molecular weight range of 400 to 10,000, preferably 500 to 6000, are in particular those polyamino compounds which are obtained by hydrolysis of corresponding NCO prepolymers based on higher molecular weight polyhydroxyl compounds and excess aromatic diisocyanates by (preferably basic) Hydrolysis can be made. Examples of this process are given in DE-OS 2 948 419, DE-OS 3 039 600, DE-OS 3 112 118, EP-A 61 627, EP-A 71 132 and EP-A 71 139. The first-mentioned patent also mentions other prior art processes for producing aromatic amino compounds of higher molecular structure, as are suitable for the process according to the invention. The process according to DE-OS 2 948 419 and the other cited patents are preferably polyether-polyamines, but also polyester-, polyacetal-, polythioether- or polycaprolactone-polyamines, preferably 2- or 3-functional polyamines, which contain urethane groups (from the reaction of the corresponding higher molecular weight polyhydroxyl compounds with the excess polyisocyanates) and which carry the amino groups on the rest of the (former) polyisocyanate. However, the aromatic, higher molecular weight polyamines can also be prepared by other processes, for example by reacting NCO prepolymers with excess amounts of aminophenylethylamine, or other diamines in accordance with DE-AS 1 694 152; FR-PS 1 415 317 describes another synthesis possibility by converting the NCO prepolymers with formic acid into the N-formyl derivatives and saponifying them. The reaction of NCO prepolymers with sulfamic acid according to DE-AS 1 155 907 also leads to higher molecular weight polyamines.

In addition to higher molecular weight polyamine compounds (from aromatic polyisocyanates) bearing amino groups bonded to aromatic radicals, higher molecular weight polyamino compounds bearing amino groups bonded to aliphatic radicals can also be prepared.

High molecular weight aliphatic di- and polyamines can also be used, as can be obtained, for example, by reductive amination of polyoxyalkylene glycols with ammonia according to BE-PS 634 741 or US Pat. No. 3,654,370. Other higher molecular weight polyoxyalkylene polyamines can be prepared by methods such as those described in the "Jeffamine, Polyoxypropylene Amines" company publication_Texaco Chemical Co., 1978, can be prepared, for example by hydrogenation of cyanoethylated polyoxypropylene glycols (DE-OS 1 193 671), by amination of polypropylene glycol sulfonic acid esters (US Pat. No. 3,236,895), by treatment of a polyoxyalkylene glycol with epichlorohydrin and a primary Amine (FR-PS 1 466 708) or by reacting NCO prepolymers with enamines containing hydroxyl groups, Aldimines or ketimines and subsequent hydrolysis according to DE-OS 2 546 536. Suitable higher molecular weight aliphatic di- and polyamines are also those according to DE-OS 29 48 419 and DE-OS 3 039 600 by alkaline hydrolysis of NCO prepolymers (with aliphatic diisocyanates) with bases accessible via the carbamate stage polyamines. These higher molecular weight polyamines have molecular weights of approximately 400 to 10,000, preferably 500 to 6000 and particularly preferably from 1000 to 3000.

The long-term storage-stable one-component reactive systems according to the invention are optionally produced with the use of further low-molecular chain extenders or crosslinking agents. These low molecular weight chain extenders or crosslinkers are bifunctional or multifunctional compounds which contain hydroxyl groups (polyols) bonded to aliphatic and / or cycloaliphatic groups and / or NH which are bonded to aromatic, including heterocyclic rings with an aromatic character₂-Groups (polyamines) and molecular weights between 62 and 399. Low molecular weight diols with hydroxyl groups bonded to aliphatic or cycloaliphatic groups are preferred, as are aromatic diamines in the molecular weight range 108 to 399.

These compounds generally have 2 to 8, preferably 2 to 4, particularly preferably 2, hydrogen atoms which are reactive toward isocyanates, such as hydroxyl and / or amino groups. Mixtures of different compounds can of course also be used. Examples of such compounds are: ethylene glycol, trimethylene glycol, 2,3-butanediol and / or -1,4, 1,6-hexanediol, neopentyl glycol, 1,4-bis-hydroxyethyl-cyclohexane, 1,4-dihydroxycyclohexane, terephthalic acid -bis (ß-hydroxyethyl) ester, 1,4,3,6-dianhydrohexite, 1,4-monoanhydrotetrite, and less preferably diols with secondary hydroxyl groups, for example propylene glycol, 2,3-butanediol, or 2,5-pentanediol. The following may be mentioned as polyvalent compounds: trimethylolpropane, trimethylolethane, hexanetriol-1,2,6, glycerol, pentaerythritol, quinite, mannitol, sorbitol, castor oil, and also di-, tri- and tetraethylene-, -propylene- and -butylene-glycols, also bis-2-hydroxyethyl) hydroquinone, bis (2-hydroxyethyl) resorcinol, formose or formite. Also suitable are diols or polyols containing tertiary amines, for example N-methyldiethanolamine, triethanolamine or N, N'-bis-hydroxyethylpiperazine.

However, low molecular weight, non-stabilized aromatic polyamines, preferably diamines, can also be used.

Aromatic polyamines are also to be understood as meaning those amines which contain the amino group bonded to heterocyclic radicals with an aromatic character. Examples of suitable aromatic polyamines are: p-phenylenediamine, 2,4- / 2,6-toluenediamines, diphenylmethane-4,4'- and / or -2,4'- and / or -2,2'-diamines, 3 , 3'-dichloro-4,4'-diaminodiphenylmethane, 3- (C₁-C₈) Alkyl-4,4'-diaminodiphenylmethane, the 3,3'-di- (C₁-C₄) -4,4'-diaminodiphenylmethane and the 3,3 ', 5,5'-tetra- (C₁-C₄) -alkyl-4,4'-diaminodiphenylmethanes, the 4,4'-_Di-aminodiphenyl sulfides, sulfoxides or sulfones, diamines containing ether groups according to DE-OS 1 770 525 and 1 809 172 (US Pat. Nos. 3,654,364 and 3,736,295), optionally substituted in the 5-position, 2-halo-1 , 3-phenylenediamines (DE-OS 2 001 772, 2 025 896 and 2 065 869), bisanthranilic acid esters (DE-OS 2 040 644 and 2 160 590), 2,4-diaminobenzoic acid ester according to DE-OS 2 025 900, and by one or two (C₁-C₄) Alkyl groups substituted toluenediamines. 3,5-Diethyl-2,4- and / or -2,6-diaminotoluene (especially their technical (80/20) or (65/35) isomer mixtures), unsymmetrically tetraalkyl-substituted diaminodiphenylmethanes, for example 3.5, are particularly preferred -Diethyl-3'-5'-diisopropyl-4,4'-diaminodiphenylmethane and its isomer mixtures according to DE-OS 2 902 090, 4,4'-diaminobenzanilide, and 3,5-diaminobenzoic acid (C₁-C₄) alkyl ester, 4,4'- and / or 2,4'-diamino-diphenylmethane, and naphthylene-1,5-diamine.

However, diols or diamines with additional groups can also be used, for example bis (2-hydroxyethyl) adipic acid, bis (2-hydroxyethyl) terephthalate, diol urethanes, diol ureas or polyols which contain sulfonate and / or contain phosphonate groups, for example 1,6-hexamethylene-bis- (2-hydroxyethyl urethane), 4,4'-diphenylmethane bis- (2-hydroxyethyl urea) or the adduct of Na bisulfite with 1,4-butenediol, or its Alkoxylation products. Further low molecular weight compounds are described in detail in DE-OS 2 854 384.

Further chain extenders or crosslinking agents which may be used are, for example, ethylenediamine, propylenediamine, hexane-1,6-diamine, 2,2,4-trimethyl-1,6-diaminohexane, 2,5-dimethyl-2,5-diaminohexane, 1.10 -Decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, bis-aminomethyl-hexahydro-4,7-methano-indane (TCD-diamine), 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 1-amino- 3,3,5-trimethyl-5-aminomethyl-cyclohexane (isophoronediamine), 2,4-and / or 2,6-hexahydrotoluenediamine, 2,4'- and / or 4,4'-diaminodicyclohexylmethane, m- or p-xylylenediamine, bis (3-aminopropyl) methylamine, bis-N, N '- (3-aminopropyl) piperazine and 1-amino -2-amino-methyl-3,3,5- (3,5,5) -trimethylcyclopentane, 2,2-dialkylpentane-1,5-diamine or triamines such as 1,5,11-triaminoundecane, 4-aminomethyl-1 , 8-diaminooctane, lysine methyl ester, cycloaliphatic triamines according to DE-OS 2 614 244, 4,7-dioxadecane-1,10-diamine, 2,4- and 2,6-diamino-3,5-diethyl-1- methylcyclohexane and mixtures thereof, alkylated diaminodicyclohexylmethanes, for example 3,3'-dimethyl-4 ', 4'-diaminodicyclohexylmethane or 3,5-diisopropyl-3', 5'-diethyl-4,4'-diaminodicyclohexylmethane, perhydrogenated diaminonaphthalenes, perhydrogenated diaminoanthrazenes, or higher amines such as Diethylenetriamine, triethylenetetramine, pentaethylene hexamine, dipropylenetriamine, tripropylenetetramine, or N, N'-dimethyl-ethylenediamine, 2,5-dimethylpiperazine, 2-methylpiperazine, piperazine (hydrate) and 2-hydroxyethylpiperazine.

The following can also be used as low molecular chain extenders: hydrazine, mostly in the form of hydrazine hydrate, C.₁-C₆alkyl-substituted hydrazines, for example methylhydrazine, ethylhydrazine, hydroxyethylhydrazine or N, N'-dimethylhydrazine. Other suitable chain extenders are compounds with hydrazide end groups, for example di- or polyhydrazides such as carbodihydrazide, hydracrylic acid hydrazide, oxalic acid dihydrazide, adipic acid dihydrazide, terephthalic acid dihydrazide, isophthalic acid hydrazide or compounds with hydrazide and semicarbazide or amino, carboxylic acid or amino, carboxylic acid or amino ß-semicarbazidopropionic acid hydrazide, 2-semicarbazidoethylene carbazine ester, aminoacetic acid hydrazide, ß-aminopropionic acid hydrazide or biscarbamate ester or bissemicarbazide such as ethylene-biscarbamate ester or ethylene-bis-semicarbazide or isophorone-bis-semicarbazide.

Furthermore, compounds which are monofunctional with respect to isocyanates in a proportion of from 0.01 to 10% by weight can also be used in the customary manner as so-called chain terminators. Such monofunctional compounds are, for example Monoamines, such as butyl or dibutylamine, stearylamine, pyrrolidine, 4-amino-2,2,6,6-tetramethylpiperidine, aniline or tolylamine, monoalcohols such as butanol, 2-ethylhexanol, cyclohexanol, ethylene glycol monoethyl ester, monooximes such as butanone oxime or other monofunctional compounds such as N, N-dimethylhydrazine or acetic acid hydrazide or benzoic acid hydrazide.

The conventional polyurethane catalysts, with particularly good effect tertiary amines or metal catalysts, can be used as catalysts C) for the long-term storage-stable one-component systems.

These are, for example, tertiary amines, such as triethylamine, tributylamine, N-methylmorpholine, N-ethylmorpholine, N-cocomorpholine, N, N, N ', N'-tetramethyl-ethylenediamine, 1,4-diaza-bicyclo- (2,2,2) octane, N-methyl-N'-dimethylaminoethyl-piperazine, N, N-dimethylbenzylamine, bis- (N, N-diethylaminoethyl) adipate, N, N-diethylbenzylamine, pentamethyl-diethylenetriamine, N , N-dimethylcyclohexylamine, N, N, N ', N'-tetramethyl-1,3-butanediamine, N, N-dimethyl-B-phenylethylamine, 1,2-dimethylimidazole and 2-methylimidazole.

Tertiary amines which have hydrogen atoms active with respect to isocyanate groups are, for example, triethanolamine, triisopropanolamine, N-methyl-diethanolamine, N-ethyl-diethanolamine, dimethylethanolamine, and also their reaction products with alkylene oxides, such as propylene oxide and / or ethylene oxide.

Silaamines with carbon-silicon bonds, as described, for example, in DE-PS 1 229 290, are also suitable as catalysts, for example 2,2,4-trimethyl-2-silamorpholine and 1,3-diethylaminomethyl tetramethyl disiloxane.

Suitable catalysts are also nitrogen-containing bases such as tetraalkylammonium hydroxides, alkali metal hydroxides such as sodium hydroxide, alkali phenolates such as sodium phenolate or alkali metal alcoholates such as sodium methylate. Hexahydrotriazines can also be used as catalysts.

Organic metal compounds, in particular organic tin compounds and lead compounds, can also be used as catalysts. Preferred organic tin compounds are tin (II) salts of carboxylic acids such as tin (II) acetate, tin (II) octoate, tin (II) ethylhexoate and tin (II) laurate and the dialkyltin salts of carboxylic acids, such as dibutyl tin diacetate, dibutyltin dilaurate, dibutyltin maleate or dioctyltin diacetate.

Further representatives of catalysts to be used according to the invention and details on the mode of action of the catalysts are in the plastics manual, volume VII, edited by Vieweg and Höchtlen, Carl-Hanser-Verlag, Munich 1966, for example on pages 96 to 102, and in DE -OS 3 230 757.

The catalysts are generally used in an amount between about 0.001 and 10% by weight, based on the reactive mixture.

The following may be mentioned as auxiliaries and additives D): dyes or pigments, fillers such as silica gel, gypsum, talc, activated carbon, metal powder, UV absorbers or stabilizers such as phenolic antioxidants, light stabilizers, blowing agents, surface-active additives such as emulsifiers or foam stabilizers, optionally cell regulators , Antiblocking agents, silicones, flame retardants, or fungistatic and / or bacteriostatic substances.

Fillers that can be used are, for example, fiber materials, ie all known inorganic and / or organic, fibrous reinforcing materials, for example glass fibers, graphite fibers and asbestos fibers or fiber materials derived from an organic polymer, for example from a polyester such as polyethylene terephthalate, or preferably aromatic polyamides, such as m-phenylene / isophthalic acid polyamide, or poly-p-phenylene terephthalamide, or also polycaprolactam. These fiber materials can also be in the form of a mat, tape, continuous fibers, fleece, fabric or as a staple fiber tangled mixture. Glass fibers which are equipped with sizes are preferred in order to give the fibers an affinity for polyurethanes. The amount of filler to be incorporated depends on the desired improvement in the mechanical properties, in general 5 to 60% by weight of fiber material are used.

If polyurethane foams are to be produced by the process according to the invention, then water and / or volatile organic substances are also used as blowing agents. Examples of suitable organic blowing agents are acetone, ethyl acetate, methanol, ethanol, halogen-substituted alkanes such as methylene chloride, chloroform, ethylidene chloride, vinylidene chloride, monofluorotrichloromethane, chlorodifluoromethane, dichlorodifluoromethane, butane, hexane, heptane or diethyl ether.

A blowing effect can also be achieved by adding compounds which decompose at higher temperatures with the elimination of gases, for example nitrogen, for example azo compounds such as azoisobutyronitrile. Further examples of propellants as well as details on the use of propellants can be found in the Plastics Manual, Volume VII, published by Vieweg and Höchtlen, Carl-Hanser-Verlag, Munich 1966, for example on pages 108 and 109, 453 and 455 and 507 to 510.

Surface-active additives (emulsifiers and foam stabilizers) can also be used. Suitable emulsifiers are, for example, the sodium salts of castor oil sulfonates or also of fatty acids or salts of fatty acids with amines such as oleic acid diethylamine or stearic acid diethanolamine. Alkali or ammonium salts of sulfonic acids such as dodecylbenzenesulfonic acid or dinaphthylmethane disulfonic acid or also of fatty acids such as ricinoleic acid or of polymeric fatty acids can also be used as surface-active additives.

Water-soluble polyether siloxanes are particularly suitable as foam stabilizers. These compounds are generally designed such that a copolymer of ethylene oxide and propylene oxide is linked to a polydimethylsiloxane radical. Foam stabilizers of this type are described, for example, in US Pat. No. 2,764,565.

There can also be reaction retarders, for example acidic substances such as hydrochloric acid or organic acid halides, cell regulators of the type known per se, such as paraffins or fatty alcohols or dimethylpolysiloxanes, and pigments or dyes and flame retardants of the type known per se, for example Tris-chloroethyl phosphate or ammonium phosphate and polyphosphate, also stabilizers against aging and weather influences, plasticizers and / or fungistatic and bacteriostatic substances, fillers such as barium sulfate, diatomaceous earth, soot or sludge chalk are also used.

Further examples of surface-active additives and foam stabilizers to be used according to the invention, as well as cell regulators, reaction retarders, stabilizers, flame-retardant substances, plasticizers, dyes and fillers, as well as fungistatic and bacteriostatic substances, and details on the use and action of these additives are given in the Plastics Manual, Volume VI by Vieweg and Höchtlen, Carl Hanser Verlag, Munich 1966, described for example on pages 103 to 113 and in DE-OSs 2 854 384 and 2 920 501.

III) PU reactive mixtures and their processing

Depending on the viscosity or melting behavior of the starting components, easily pourable, doctorable or solid, easily meltable (one-component) PU reactive mixtures are obtained at room temperature. These reactive mixtures represent a heterogeneous suspension of the solid, stabilized diamines in the polyol and / or polyamine components and the polyisocyanates or NCO prepolymers. The heat crosslinking of this mixture is optionally carried out in accelerated form when suitable catalysts D) are added. If only the polyamine compounds, which are significantly more reactive towards NCO groups, are used, there is no need to add catalysts.

Another feature of the one-component PU reactive systems is that the one-component systems stabilized according to the invention crosslink within a few minutes after reaching a temperature (which is dependent on the amount and type of stabilizer isocyanate). This means that on the one hand below this temperature ("thickening temperature") even a long flow path of the still uncrosslinked reactive mixture allows the hot mold to be filled completely, but on the other hand the subsequent rapid solidification of the casting batches after the temperature has increased permits rapid demolding cycles. The advantage of the invention is also the very long storage time of the starting reactive systems, even at higher storage temperatures (for example up to 60 ° C.). The advantage over the prior art, where a reaction delay in one-component systems can only be achieved by "heterogeneity" of one or more components, is additionally considerably improved here by protection by means of a polyadduct coating, the "protection" only by the heat shock (or very strong Shear or dissolving using highly polar solvents) can be removed. Using the polyamine suspensions according to the invention, the possible uses of one-component systems are significantly broadened. An essential feature of the one-component systems according to the invention is that solid aromatic diamines, such as, for example, are also used in these systems Use 4,4'-diaminodiphenylmethane, 2,4- or 2,6-diaminotoluene, 1,5-diaminonaphthalene or 3,3 ', 5,5'-tetramethyl-4,4'-diamino-diphenylmethane as stabilized chain extenders of retarded reactivity can without losing the character of a one-component system. If, on the other hand, these diamines mentioned are reacted in an unstabilized form in one of the previously customary process techniques with NCO prepolymers, this sometimes results much shorter casting times, so that a perfect course of these approaches in the tool part is not possible.

The PU one-component reactive systems according to the invention, which may contain catalysts, are essentially solidified by heat shock. At room temperature or slightly elevated temperature, surprisingly, no crosslinking reaction occurs even in the presence of these highly effective catalysts, so that catalyst-containing mixtures can also be referred to as one-component systems which are stable in long-term storage.

The processing of the one-component systems according to the invention depends on their nature. Liquid systems that can be cast at room temperature can be processed in the casting process; if necessary, they are heated briefly before processing, for example to 50-70 ° C. Processing can also be carried out by centrifugal casting;

Hollow bodies can be produced by introducing the reactive mass into heated molds with distribution on the surface by means of appropriate rotational movements.

Even after the slush molding process, heated molds can be filled with the reactive compound. After a certain heating time / reaction on the heated mold surface, excess, unreacted reaction mass is poured out of the molds again.

If blowing agents are also used, cellular polyurethanes can be produced, which may have an integral density structure.

Systems that are no longer castable but still running can, for example, be applied with a squeegee to the desired documents, e.g. textile documents such as nonwovens, knitted fabrics and fabrics, (split) leather, matrices (e.g. suede leather-silicone matrices), or intermediate supports (e.g. release papers) Formation of coatings or dressings, applied and then solidified by heat shock.

Plastic systems (pastes) can be hot-pressed under pressure and shaping, whereby 5 to 15 minutes are sufficient for solidification at 120 ° C.

Surface coatings, impression molds or moldings can also be produced by immersion processes by immersing the heated molds to be coated in the reactive composition.

The reactive mass can also be pressed through slots or nozzles into hot media (hot air or hot liquids) and thereby solidified.

The reactive composition can be partially or largely reacted to form polyurethane in heated extruders and extruded in this form through slots or nozzles and, if appropriate, completely reacted in hot media, or introduced into hot molds, from which it can be removed from the mold after a short time. The reactive composition can also be processed using the reaction injection molding (RIM) process.

Solid systems, in particular based on higher melting starting polyols (45 to 65 ° C) are processed either under pressure and molding (injection molding) or at about or above the melting temperature of the polyol. The procedure can be such that the previously produced one-component systems in the form of solid granules are introduced into a mold warmed to above the melting point of the polyol (generally below 60 ° C.). After the granules have melted and the mold has been filled with them, the mold is heated to 100 to 140 ° C and the contents solidified.

The solidification temperature of the one-component systems according to the invention depends on the amount and chemical constitution of the polyisocyanates used to stabilize the polyamines. As the solidification temperature increases, the solidification time to form the polyurethanes decreases. Depending on the temperature, the baking time can range from less than 1 minute to several hours. Sometimes it is advantageous to anneal the plastics at 100 ° C for a while after demolding to ensure complete hardening.

However, the one-component reactive systems can also be cured by adding preferably highly polar solvents such as dimethylformamide, N-methylpyrrolidone, or moderately polar solvents such as propylene carbonate, dioxane or glycol monomethyl ether acetate. Depending on the amount of these solvents, the stabilizing effect in the one-component systems can be partially or completely eliminated. The casting time (pot life) of such batches can be controlled by the amount of such solvent additives. With small quantities, systems with a pot life of several days at room temperature are obtained, while with higher doses, solidification occurs quickly or even suddenly after 10 to 15 minutes. The amount of such solvents also depends on the amount and type of stabilizer (quality of the polyadduct skin on the polyamino surface) and is determined for the respective systems after practical preliminary tests. The technical advantage of such reaction mixtures is that these systems solidify even without the addition of heat. Of course, the thermal solidification time of the one-component systems can also be reduced by suitable metering of the solvents, with sufficient storage stability still being possible.

Furthermore, the one-component systems according to the invention can also be solidified by using high shear forces, for example in high-speed agitators. The heat that occurs during brief stirring usually does not reach the crosslinking thickening temperature of the one-component systems, so that the polyurea skin located on the surface of the polyamine particles is destroyed only by mechanical stress during the stirring process.

Further embodiments of the stabilization under different conditions or methods for producing the one-component reactive systems and their curing can also be found in the examples.

Preferred PU reactive systems are those which contain higher molecular weight polyamines as components and thus produce high-quality elastomers, coatings, cellular elastomers and molded parts with, if appropriate, a density distribution with a cellular inner core and denser outer skin.

example 1

To a suspension of 7.25 g (45.8 mmol) of powdered 1,5-diaminonaphthalene (NDA) (particle size 10-50 _Nm) in 20 g of dioctyl phthalate, the polyisocyanate X mentioned below is added in the stated amount. The reaction mixture is left to stir at room temperature for a few hours to form the stabilized diamine with retarded reactivity. 100 g of an NCO-containing pre-adduct (NCO = 3.6% by weight), which was prepared in a known manner from a linear polypropylene glycol ether (MW = 2000, OHZ = 56) and 2,4-diisocyanatotoluene, are then added. The two components (NH_2/NCO reaction). Depending on the extent of the deactivation of the NDA particles due to superficial polyurea formation, a temporally different viscosity build-up of the reaction batches is observed at room temperature.

The point in time at which the viscosity of the batches has reached a value of 40,000 mPas is now determined.<tables id="tabl0004" num="0004"><img file="EP0171015A2_D0004.tif" /></tables><tables id="tabl0005" num="0005"><img file="EP0171015A2_D0005.tif" /></tables>The deactivating influence of the polyisocyanates on the NH₂/ NCO reaction is clearly recognizable in this test series, especially when using IPDI and biuretized 1,6-diisocyanatohexane compared to the zero test (No. a).

The batches can each be cured by heating at 135 to 140 ° C. for 1 hour to give elastomeric polyurethanes (urea).

Example 2

To a suspension of 40 g 1,5-diaminonaphthalene (NDA) in 50 g of a linear polypropylene glycol ether (MW = 2000, OHZ = 56) is added a solution of 7.5 g trimerized IPDI (NCO = 14, 8%) in 5 g of toluene (corresponds to 5.2 eq.% Isocyanate on eq. Amine). After a stirring time of 4-5 h, 14 g of this suspension of the stabilized diaminonaphthalene were intimately mixed with 100 g of the NCO pre-adduct mentioned in Example 1, consisting of a linear polypropylene glycol ether and 2,4-diisocyanatotoluene (NCO = 3.6%). The viscosity is gradually increased at room temperature and a viscosity of 40,000 mPas is obtained after 65 minutes.

By heating the reactive mixture to 130 ° C., an elastomeric polyurethane urea is obtained.

Example 3

If 100 g of the NCO pre-adduct mentioned in Examples 1 and 2 are mixed with 14 g of a suspension of 40 g of NDA in 50 g of the linear polypropylene glycol ether in which the 1,5-diaminonaphthalene was not deactivated by the addition of trimeric IPDI, so a viscosity of 40,000 mPas is reached after just 21 minutes.

In comparison to Example 2 (deactivated NDA), the polyaddition of the starting components takes place at a significantly higher rate (factor-v3).

Example 4

The following polyisocyanates X were added to a suspension of 50 g of 2,4-diaminotoluene (TDA) in 50 g of a linear polypropylene glycol ether (MW = 2000, OHZ = 56) in the stated amount. After a stirring time of several hours at a slightly elevated temperature (up to 50 ° C.), 10.5 g of the now deactivated TDA / polyether suspension, cooled to room temperature, were mixed with 100 g of the NCO preadduct described in Example 1 (NCO = 3.6 %) intimately mixed. There is a gradual increase in viscosity at room temperature. As a measure of the reactivity of the deactivated TDA towards the NCO groups, the point in time until 10,000 or 40,000 mPas / RT is reached is determined.<tables id="tabl0006" num="0006"><img file="EP0171015A2_D0006.tif" /></tables><tables id="tabl0007" num="0007"><img file="EP0171015A2_D0007.tif" /></tables>

Also in this example is the deactivating influence on the NCO / NH₂-Reaction, especially when using IPDI and biuretized 1,6-diisocyanatohexane, clearly recognizable.

Compared to the comparison test (no. A), the reaction mixtures mentioned have a sometimes considerably longer casting time (pot life).

Example 5

To a suspension of 40 g of 1,5-diamino-naphthalene (NDA) in 50 g of a linear polypropylene glycol ether (MW = 2000, OHZ = 56), the amounts of biuretized 1,6-diisocyanatohexane (NCO = 22, 5%) added. After a stirring time of 4-5 h at 30-50 ° C., 14 g of this suspension (6.2 g deactivated NDA and 7.8 g polyether as suspension medium) were mixed with 100 g of the NCO pre-adduct based on polyether (see Example 1; NCO = 3.6%) mixed.

The crosslinking temperature of the reaction mixture is now determined as a measure of the deactivation of the NDA present in the heterogeneous phase. For this purpose, a thin film of the mixture is applied on a KOFLER heating bench over a temperature range of 40 to 250 ° C. After 15 minutes the minimum temperature at which this film begins to crosslink elastically is determined. If the crosslinking temperature is&gt; 50 - 60 ° C, experience shows that the reaction batch is stable for months at room temperature and retains after 1 - 2 days (after the reaction of the polyether present in small quantities in the NDA / suspension with the NCO pre-adduct ) its viscosity constant.<tables id="tabl0008" num="0008"><img file="EP0171015A2_D0008.tif" /></tables><tables id="tabl0009" num="0009"><img file="EP0171015A2_D0009.tif" /></tables>If the liquid reaction mixture specified under c), which is stable at room temperature with the exclusion of moisture after a brief degassing in a vacuum, is poured into a mold provided with a release agent and heated for 1 to 2 hours at 140 ° C., a highly elastic PUR elastomer with the following mechanical properties is obtained :<tables id="tabl0010" num="0010"><img file="EP0171015A2_D0010.tif" /></tables>

Example 6

14 g of the deactivated NDA / polyether suspension described in Example 5 with 100 g of an NCO preadduct of a linear polyester based on adipic acid and ethylene glycol with a molecular weight of 2000 (OHZ = 56) and 2,4-diisocyanatotoluene (NCO content of Pre-adduct = 3.6% by weight) stirred at 50-60 ° C., the reaction batches obtained show the following crosslinking temperatures (KOFLER-Bank method, see Example 5):<tables id="tabl0011" num="0011"><img file="EP0171015A2_D0011.tif" /></tables>Here too, the reaction batches c) to f) are stable in storage at room temperature with the exclusion of moisture. If the batch described under c) (crosslinking temperature: 120 ° C.) is crosslinked at 140 ° C. under the processing conditions mentioned in Example 5, a PUR elastomer with the following mechanical value level is obtained:<tables id="tabl0012" num="0012"><img file="EP0171015A2_D0012.tif" /></tables>

Example 7

1.5 g of biuretized 1,6-diisocyanatohexane are added to a suspension of 40 g of finely powdered 4-aminobenzoic acid (4-aminoanilide) (4,4'-diamino-benzanilide) in 50 g of the linear polypropylene glycol ether (OHZ = 56) . The reaction mixture is stirred for a further 3-5 hours at room temperature.<ul id="ul0002" list-style="none"><li>a) 22 g of this suspension were mixed with 100 g of the aforementioned polyether-based NCO pre-adduct (NCO = 3.6%) (Example 5). The reaction mixture is stable in storage at room temperature and shows a crosslinking temperature of 120 - 125 ° C on the KOFLER bench. If the liquid mixture is brought to a temperature of 130 - 140 ° C in a vacuum after a short degassing phase, a bubble-free PUR elastomer with the following mechanical properties is obtained after 1 to 2 hours:<img file="EP0171015A2_D0013.tif" /></li><li>b) If the NCO pre-adduct based on polyether is replaced by a corresponding NCO prepolymer based on polyester (polyester made of adipic acid and ethylene glycol, MW 2000, OHZ = 56), 22 g of the 4,4'-diamino-benzanilide / Polyether suspension per 100 g NCO pre-adduct (NCO = 3.6%) is also a PUR system that is stable at room temperature, which can be brought into a pourable state by melting (50 - 60 ° C) before processing (crosslinking temperature: 115 - 120 ° C). The PUR elastomer produced under the processing conditions already mentioned (1 to 2 h at 130 - 140 ° C) has the following mechanical properties:<img file="EP0171015A2_D0014.tif" /></li></ul>

Example 8

When using the suspension described in Example 7 of 40 g of 4,4'-diaminobenzanilide in 50 g of a linear polypropylene glycol ether, but which was not treated by adding 1.5 g of biuretized 1,6-diisocyanatohexane, the results under 7a and 7b described the following pouring times (pot lives):<ul id="ul0003" list-style="none"><li>a) 100 g of NCO pre-adduct / base: polyether 22 g of suspension (not deactivated) casting time at room temperature = 15-25 min, ie after this time the reaction mixture can no longer be processed using the customary casting methods.</li><li>b) 100 g NCO pre-adduct / base: polyester 22 g suspension (not deactivated) casting time at 70-80 ° C: 5 to 10 min.</li></ul>

Example 9

4 g of isophorone diisocyanate (IPDI) were added to a suspension of 40 g of ethylene glycol bis (p-amino-benzoic acid ester) in 50 g of a linear polypropylene glycol ether (MW = 4000, OHZ = 28). After standing for one day at room temperature, 26 g of this suspension were mixed with 100 g of an NCO pre-adduct based on a polypropylene glycol ether (MW = 2000, OHZ = 56) and 2,4-diisocyanatotoluene (NCO = 3.6% by weight) . The reaction mixture is now stable in storage at room temperature (exclusion of moisture), but solidifies after a few hours at a temperature of 120-130 ° C. After an annealing time of 24 h at 110⁰C the following mechanical values ​​were measured on a sample plate:<tables id="tabl0013" num="0013"><img file="EP0171015A2_D0015.tif" /></tables>

Without the deactivating addition of IPDI, the pouring time of the above combination is approx. 120 min at room temperature.

Example 10

4 g of IPDI were added to a suspension of 40 g of 4,4'-diamino-3,3'-dicarboxymethyl-diphenylmethane in 70 g of a linear, high molecular weight polypropylene glycol ether (MW = 4000, OHZ = 28). After stirring for several hours at 30-50 ° C., 35 g of this suspension were mixed with 100 g of the polyester-based NCO pre-adduct (NCO = 3.6%). The crosslinking temperature in this approach is 110-120 ° C. After 1 to 2 days the viscosity of the reaction mixture remains constant. A solidification takes place only by heat impact, whereby at 120 - 130 ° C an elastic PUR material with a hardness of 72 Shore A is created.

Without the stabilizing addition of 4 g IPDI, the suspension (35 g) in combination with the NCO pre-adduct (100 g) shows a pouring time of 2-3 hours at room temperature. The mixture is therefore not stable in storage at room temperature.