DE2347299A1 - Polyurethane-polyurea gel prepn. - from isocyanate-contg. prepolymers and polyamine chain extenders in water and or alcohols - Google Patents

Abstract

Polyurethane-polyurea gel prepn., by reacting NCO gp.-contg. prepolymers (I) with chain extenders in water and/or alcohols, takes place by using, as (I), reaction products of (1) OH gp.-contg. polyethers contg. >40 wt. % C2H4O-units with (2) polyisocyanates, in NCO/OH ratio >1, esp. 2-10, and using di- or polyamines as chain-extenders. Up to 50 vol. % fillers can be added, e.g. silicates, fibres, soaps, plant nutrients, salts, fertilisers, or aq. solns. of other natural or synthetic polymers. The gels are useful for prodn. of cushioning elements, shock-absorbers, fire-resistive coatings, flame-proof insulators, binders for solid and fibrous fillers, substrates for plant-nutrients. Gels are highly stable. Dispersant, i.e. water or alcohol, is strongly bonded in gel, and does not escape by evaporation or diffusion.

Description

Central area of patents, trademarks and licenses

Sf t- Je Y 509 Leverkusen, Bayerwerk

19 Sep 1973

Process for the production of polyurethane-polyurea gels

The present invention relates to the production of novel stable water- or alcohol-containing polyurethane urea gels. The gels can contain up to 98% by weight of solvent, without significant evaporation of the enclosed solvent in the air.

It is known in principle, polyurethane-polyurea polymers to manufacture. For this purpose, polyisocyanates or reaction products of polyols and excess polyisocyanates are used with polyfunctional amines or with water. While in the first case, depending on the chemical nature and amount of The starting components used, hard to elastic, compact masses are obtained when the chain is lengthened with water and the simultaneous presence of certain additives, such as catalysts or foam stabilizers, Foams, in common parlance as polyurethane foams are designated. The production of these materials, also under technical conditions, is well known and recorded in numerous publications, e.g. in R. Vieweg, A. Höchtlen, Kunststoff-Handbuch Vol. VII, Polyurethane, Hanser-Verlag Munich, 1966.

Le A 15 210 - 1 -

509815/1044

The polyurethane-polyurea polymers are usually produced in such a way that the individual components are mixed with one another in the absence of solvents. at some technical processes, for example the production of certain elastomer coatings or elastic ones Fibers, will the. Reaction also carried out in solvents which are inert towards the isocyanate groups, e.g. in dimethylformamide. According to the teaching of the American patent specification 3.574.I5O are made by reacting polyaryl-polyalkylene-polyisocyanates with certain polyol mixtures in inert organic solvents in which the resulting Polymers is essentially insoluble, polyurethanes obtained, which have a porous structure. While their formation, which is completed after about 8 to 30 minutes, will go through a very unstable gel state, which can be recognized by the fact that the clear solution has an opaque appearance.

Similar processes for the production of microporous moldings by isocyanate polyaddition reactions in poor solvents are also disclosed in DOS 1,694,230, U.S. Patent 3,582,396, U.S. Patent 3,681,125 and DOS 1,769 described.

It has now been found that stable polyurethane-polyurea gels are obtained can be obtained if prepolymers containing isocyanate groups and made from polyethers with more than 40% by weight Reacts ethylene oxide units in water or alcohols with diamines or polyamines as chain extenders. The expression Gel is supposed to describe the physical nature of the jelly-like or jelly-like end product as the exact physical structure of the polymer according to today's views of colloid chemistry about this state reproduce. However, it should not be ruled out that the novel gels are in some cases the same homogeneous

Le A 15 21D - 2 -

509815/1044

.3.

Have a structure as it is generally ascribed to gels today, i.e. that more or less strongly branched polymer networks swollen by water or alcohols the polyurethane-polyureas are present.

The implementation of the individual components with the formation of the new types of water and / or alcohol-containing gels takes place spontaneously without the dispersants reacting with the isocyanate groups via their hydroxyl groups. Due to the high speed of formation, the production of the gels can very easily be designed continuously, which is very advantageous for many purposes.

Subject -the present patent application is therefore a process for preparing polyurethane-polyurea Gelendurch reaction of isocyanate groups containing prepolymer with chain-extending agents in water and / or alcohols, which is characterized in that as isocyanate groups prepolymers are reaction products of hydroxyl group-containing polyethers having more than 40 wt. 96 ethylene oxide units with polyisocyanates in an NCO / OH ratio greater than 1, and di- or polyamines used as chain extenders.

The gels can be produced in various ways. It is thus possible to add all the components, ie the prepolymer, the dispersant, ie water and / or alcohol, and the chain lengthening agent together in one shot. But you can also first prepare a solution of the prepolymer in water or alcohol and then mix this either with the pure chain extender or a solution of the same in additional water and / or alcohol. In any case, gel formation occurs after a short time .

Le A 15.210 - 3 -

5098 1 5/104

• «f.

Intensive mixing of the starting components facilitates gel formation and the quality of the gels improved. The mixing can in the simplest case in a zone of increased turbulence caused by a mechanical Stirring device is caused, take place. Better results are obtained when using fast running ones Mixing units, for example of centrifugal homogenizing machines or of agitator mixing chambers known from the literature or commercially available polyurethane foaming machines, Intensive mixing can also be achieved by using the mixing devices of polyurethane foaming machines Achieve where mixing by countercurrent injection he follows.

The prepolymer made from ethylene oxide-rich polyethers and polyethers with higher functionality Polyisocyanates that still contain free isocyanate groups at the end are converted by reacting the corresponding Polyether with an excess amount of polyisocyanate, i.e. with an NCO / OH ratio greater than 1, preferably 1.5-20, particularly preferably 2-10, produced.

The optimum ratio for carrying out the process depends in each case on the molecular weight, the functionality and the structure of the polyether. In general, the isocyanate contents of the prepolymers should be between 2 and 20% by weight , preferably between 5 and 10% by weight.

Essentially stoichiometric amounts of prepolymers and amines are required for the formation of the gels. In the The technical implementation of the process is, however, necessary in order to achieve a suitable residence time in the mixing units. proved to be advantageous to work with an excess of the amine component, i.e. at an NHp / NCO ratio greater than 1, preferably from 1 to 1.2.

Le A 15 210 - 4 -

509815/1044

♦ b *

When the gels are formed, the amount of water and / or alcohol present is variable within wide limits and is not critical. Based on the total mass of the gel, the weight of alcohol and / or water can be up to 98 % . However, the properties of the gels obtained are strongly influenced by the quantitative ratio between the polymer and the dispersant. In general, the gels become more stable and harder with increasing polymer content and softer and less structurally stable with decreasing polymer content up to the limit of about 2% by weight.

In addition to water, suitable dispersants are optionally branched (cyclo) aliphatic alcohols having 1 to 8 carbon atoms, for example methanol, ethanol, isopropanol, ethylene glycol and butanol.

It is particularly surprising that the gels according to the invention are extremely stable. Even after long periods of storage there is no visible phase separation, which would be noticeable, for example, through a clouding of the material. The dispersant is very tightly bound in the gel, so that no noticeable evaporation or diffusion of the water and / or Alcohol occurs.

Starting material for the process according to the invention are Polyethers containing at least 2 active hydrogen atoms and having a molecular weight of 500-10,000, preferably 2000-8,000 j which contain at least 40% by weight of ethylene oxide groups. Such polyethers are made by reacting compounds with reactive hydrogen atoms, e.g. Polyalcohols, with ethylene oxide and optionally alkylene oxides such as propylene oxide, butylene oxide, styrene oxide, epichlorohydrin or mixtures of these alkylene oxides produced. Suitable polyalcohols and phenols are e.g. ethylene glycol, Diethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,2-decanediol,

Le A 15 210 - 5 -

50981 5/1044

Butyn-2-diol-1,4, glycerine, butanediol-2,4, hexanetriol-1,3,6, Trimethylolpropane, resorcinol, hydroquinone, 4,6-di-tert-butylpyrocatechol, 3-hydroxy-2-naphthol, 6,7-dihydroxy-naphthol, 2,5-dihydroxy-l-naphthol, 2,2-bis (p-hydroxyphenyl) propane, Bis- (p-hydroxyphenyl) methane and cC, öL, (Ο, -ΤΓίβ-ί Hydroxyphenyl) alkanes such as 1,1,2-tris (hydroxyphenyl) ethane or 1,3-tris (hydroxyphenyl) propane.

Other suitable polyethers are the 1,2-alkylene oxide derivatives of aliphatic or aromatic mono- or polyamines, such as ammonia, methylamine, ethylenediamine, N, N-dimethylethylenediamine, Tetra- or hexamethylenediamine, diethylenetriamine, ethanolamine, diethanolamine, oleyldiethanolamine, Methyl diethanolamine, triethanolamine, aminoethylpiperazine, o-, m- and p-phenylenediamine, 2,4- and 2,6-diaminotoluene, 2,6-diam'ino-p-xylene and polynuclear and condensed aromatic polyamines, such as 1,4-naphthylenediamine, 1,5-naphthylenediamine, benzidine, toluidine, 2,2-dichloro-4,4'-diaminopdiphenylmethane, 1-fluorenamine, 1,4-anthradiamine, 9,10-diamino-phenantrene or 4,4'-diaminoazobenzene. as The starting molecules of the polyether also come from resin-like materials of the phenol and resol type in question.

All these polyethers are built up using ethylene oxide, at least 40 % of the alkylene oxide groups being ethylene oxide.

As starting components to be used according to the invention there are also aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic polyisocyanates into consideration, such as those by W. Siefgen in Justus Liebigs Annalen der Chemie, 562, pages 75 to 136, are described, for example ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, cyclobutane-l ^ -diisocyanate, cyclohexane-l ^ - and -1,4-diisocyanate and any mixtures of these isomers, 1-isocyanato-3 »3» 5-trimethyl-5-isocyanatomethylcyclohexane (DAS 1,202,785),

Le A 15. 210 - 6 -

509815/1044

2,4-land 2,6-hexahydrotoluylene diisocyanate and any mixtures of these isomers, hexahydro-1,3- and / o, 1,4-phenylene diisocyanate, perhydro-2,4 ^f - and / or -4.4 ^L diphenylmethane diisocyanate, 1,3- and 1,4-phenylene diisocyanate, 2,4- and 2,6-tolylene diisocyanate and any mixtures of these isomers, diphenylmethane-2,4 ¹ - and / or -4,4 ^f -diisocyanate, naphthylene -l ^ -diisocyanate, triphenylmethane-4,4 ', 4 "-triisocyanate, polyphenyl-polymethylene-polyisocyanates, as they are obtained by aniline-formaldehyde condensation and subsequent phosgenation and are described, for example, in British patents 874 430 and 848 671, perchlorinated aryl polyisocyanates, as described, for example, in German Auslegeschrift 1.157.601, polyisocyanates containing carbodiimide groups, as described in patent 1.092.007, diisocyanates as described in American patent 3.492.330 containing allophanate groups Polyisocyanates according to British patent specification 994.890, the Belgian patent specification 761.626 and the published Dutch patent application 7.102.524, polyisocyanates containing isocyanurate groups, as they are, for example, in the German patents 1.022.789, 1.222.067 and 1.027.394 and in the German laid-open specifications 1.929.034 and 2; 004.048, polyisocyanates containing urethane groups, as described, for example, in Belgian patent 752,261 or in American patent 3,394,164, polyisocyanates containing acylated urea groups according to German patent 1,230,778, polyisocyanates containing biuret groups, as described, for example, in the German patent 1.101.394, in British patent specification 889.050 and in French patent specification 7.017.514, polyisocyanates prepared by telomerization reactions, as described, for example, in Belgian patent specification 723.640, polyisocyanates containing ester groups, such as them for example in British patents 956,474 and 1,072,956, in the American patent

Le A 15 210 - 7 -

509815/1

3,567,763 and in the German patent specification 1,231,688 are mentioned or reaction products of the above Isocyanates with acetals according to German patent 1,072,385.

Aliphatic, cycloaliphatic or aromatic di- or polyamines are used as low molecular weight crosslinking agents or chain extenders. Examples of such compounds are: ethylenediamine, hexamethylenediamine, diethylenetriamine, hydrazine, guanidine carbonate, Ν, Ν'-diisopropylhexamethylenediamine, 1,3-bis-aminomethyl-benzene, N, N'-bis- (3-aminopropyl) ethylenediamine, N , N '-Bis (2-aminopropyl) ethylenediamine, N, N ¹ -bis- (2-aminoethyl) -ethylenediamine, 4,4'-dimethylamino-diphenylmethane, 4,4'-dimethylamino-3 »3 ^f -dimethyl- diphenylmethane, 4,4'-diamino-diphenyl-methane, and 2,4- or 2,6-diaminotoluene.

The prepolymers are prepared from the polyethers and the polyisocyanates by known processes, with NCO / OH ratios greater than 1 can be set.

In the preparation of the gels can also be significant Extensive (up to about 50 volume ^) the most diverse fillers are added, such as silicates, the most diverse Silicic acid types, aluminum oxides, the tin oxides, antimony trioxide, titanium dioxide, graphite and graphitized carbon, Soot, retort carbon, drifting sand, powdery types of cement, a wide variety of inorganic and organic color pigments, e.g. iron oxide pigments, lead chromate, lead oxide and Hennige. Short or Use long fibers made from natural or synthetic materials such as cellulose flour. It is also possible in the manufacture of gels soaps, surfactants, plant nutrients, salts, fertilizers or aqueous solutions of other natural or other to add synthetic polymer.

Le A 15 210 - 8 -

509815/1044

As mentioned at the beginning, there is a particular advantage of the invention Method in that it can be made continuous very easily.

The NCO group-containing hydrophilic prepolymer Bowie separately therefrom the chain extender and the dispersant are for this purpose at a temperature above the melting point and below the decomposition point of NCO prepolymer and chain extender continuously introduced into a mixing zone in such a mass flow, that the isocyanate polyaddition has not yet been completed in the mixing zone. That still flowable or deformable, highly water- or alcohol-containing polyurethane gel is then continuously removed from the mixing zone and optionally then passed through a short dwell tube which is provided with a profile mouthpiece is, so that the resulting polyurethane gel is obtained as a molded endless strand, tape or sheet goods.

You can also use the mixing space in addition to the prepolymer, the chain extender and add a gaseous component to the dispersant, which in its volume flow the multiple (1 to 10 times ^ the volume of the liquid Phase can be.

In this way, air-containing gels are created, whose density (kg / nr) depends on the amount of air installed the compact material is more or less greatly reduced.

The volume flows that are continuously fed into the mixing chamber are also used in this process variant expediently chosen so that the polyaddition in the mixing zone is not yet complete. That still flowable or deformable, heavily solvent-based

Le A 15 210 - 9 -

K0 9 8 15/1044

Polyurethane gel foam is then continuously removed from the mixing zone again and, if necessary, subsequently passed through a short dwell tube, which is provided with a profile mouthpiece, so that the resulting polyurethane foam gel is obtained as formed endless strand, tape or sheet goods.

The reaction between the prepolymer and the chain extender is very rapid and highly exothermic. By varying the following parameters, the reaction temperature and thus the reaction rate are adjusted so that the components within the reaction vessel are reacted with one another by about 60-90%, preferably about 75-80 %:

1) Throughput: "The higher the throughput per unit of time chosen for the given dimensions of the mixing vessel and residence zone becomes, the lower the degree of implementation will of course be. The throughput may also be be regulated by a constriction on the outlet nozzle of the mixing zone;

2) temperature of the input components;

3) Amount of chain extender: the greater the excess of the chain extender used compared to the NCO prepolymers, the faster the reaction. In general, NHp / NCO of

worked approx. 1.0 to 1.2.

4) Mixing intensity: It goes without saying that this is also due to the Mixing process the energy supplied to the system has an influence on the reaction rate.

Le A 15 210 - 10 -

5098 15 / Ί044

In general, it is necessary to throttle by varying the mentioned parameters, the reaction temperature to below 60 ⁰ C so that the mixing zone a not yet fully and completely cured gel can be removed. In the process according to the invention, however, the degree of conversion of the reaction mixture can advantageously be monitored in a simple manner by measuring the pH. At a ratio of NHg / NCO of 1.0, the pH of the fully reacted mixture is 7, and the number is 1.2, around 8. In any case, the pH value of the system is between 11 immediately when the starting components are mixed together and 14, then to decrease to its final value in the course of about 10 to 120 seconds.

Is the reaction between prepolymers and chain extenders taking place Too fast compared to the mixing speed, then inhomogeneous gels result as a result of phase separation. By suitable variation of the above parameters can be calibrated however, easily ensure homogeneous gel formation.

What has just been said also applies accordingly if the production of a foam gel is to be designed continuously.

From the above it can be seen that the gels according to the invention make sense on a large scale be produced continuously, since in each case the mixing zone is very small compared to the volume to be mixed have to be. The ancillary equipment such as Lagerkeesel, pumps and Tanks are therefore large compared to the actual production zone. That is also the reason why one has such plants can easily be mounted on trucks in order to manufacture the product directly at the point of use of the consumer (e.g. agriculture or construction industry). A schematic arrangement for continuous Implementation of the method according to the invention is shown in FIG. The liquid phase (water and / or

Le A 15 210 -11-

509815/1044

Alcohol) is taken from tank 1, via the pump (2) and the heat exchanger (3) and blended with the solution of the chain extender from tank 4 via pump (5) and fed to the mixing device (6) in such a way that it reaches the mixing zone 6a separately from the prepolymer. The prepolymer is from tank 7, which is provided with a temperature control jacket, via pump 8 and heat exchanger 9 of the mixing zone 6a of the mixing device (6) supplied. If necessary, a gas is introduced into the interior of the mixing zone via the gas meter 10.

The product leaves the system via the outlet nozzle 11 as continuous goods, which are now fed to further consumption can.

It is of course also possible in continuous operation to add various types of fillers to the gel in the mixer 6. For example, seeds or fertilizers and / or pesticides can be added to the reaction mixture and the Lay strand material directly in seed grooves.

The gels obtained can be used for the most varied of purposes. Due to their high elasticity, they can be used as upholstery elements or shock-absorbing parts, water gels are suitable due to their flame retardancy for the production of fire-resistant linings and water gels containing phytonutrients as substrates for hydroponics. They are also excellent binders for solid and fibrous fillers. Air-based water gels , for example, are excellent flame-retardant insulation materials.

Le A 15 210 - 12 -

509815/1044

Example 1;

a) Production_of_Prep_olYmeren

43.3 kg of a polyether alcohol based on glycerol with 40 wt -.% Propylene oxide and 60% ethylene oxide, a hydroxyl number of 28 and a Mplekulargewicht of 6000 are placed in a kettle, 6.8 kg of hexamethylene diisocyanate was added and with stirring for 6 hours at 110 - 120 ⁰ C heated. The prepolymer obtained has an isocyanate content of 5.13% (calculated 5.0 %) and a viscosity of 7990 centipoise at 25 ° C.

b) Production_ _{> of} the_gel

500 parts by weight of the prepolymer described under la) are emulsified in 4000 parts by weight of water to form a component A; on the other hand, 16 parts by weight of ethylenediamine are dissolved in 5000 parts by weight of water to form a component B. By means of high-pressure injection pumps, both components are conveyed separately into a mixing chamber, in which they are mixed with one another by countercurrent injection. A milky emulsion emerges from the chamber, which is converted into a form in which solidification occurs in the course of 2 seconds. A gel is formed that contains around 95 percent by weight of water and 5 percent by weight of polyurethane-polyurea polymer. The gel is highly elastic and, at 20 % load, has a compressive stress of 4.5 KPa (kilopascals) after the 1st and a compressive stress of 3.0 KPa after the 4th load. It can be repeatedly frozen by cooling to -1O ⁰ C and thawed by heating, without losing its properties.

Le A 15 210 '- 13 -

50981 5/1044

Example 2;

a) Production_of_ the_pre20lYmer

38.6 kg of a trifunctional polyether started on glycerol, which contains 40 percent by weight propylene oxide and 60 percent by weight ethylene oxide units, has a hydroxyl number of 28 and a molecular weight of 6000, are placed in a kettle, 11.4 kg of hexamethylene diisocyanate are added and the mixture is stirred for 6 hours heated 120 ⁰ C - to 110th The prepolymer obtained has an isocyanate content of 10.3 % (calculated 10.0 %) and a viscosity of 1269 centipoise at 25 ° C.

30 parts by weight of the prepolymer described under 2a) are emulsified in 60 parts by weight of water to form an A component; At the same time, 1.56 parts by weight of ethylenediamine are dissolved in 10 parts by weight of water to form a B component. By means of pumps, 90 parts by weight of component A and 11.56 parts by weight of component B are conveyed separately to the mixing chamber of a polyurethane foaming machine, in which the mixing takes place by means of a stirrer. The emerging mixture forms a very hard, pressure-resistant water gel in a mold after one second, which has a polymer content of 30 % .

Example 3:

a) Manufacture of the prep oil

687 g of a trifunctional polyether started on glycerine, which contains 40 percent by weight propylene oxide and 60 % ethylene oxide units, has a hydroxyl number of 28 and a molecular weight of 6000

Le A 15 210 - 14 -

50981 5/1044

4 ·

placed in a flask, 113 g of tolylene diisocyanate (80% 2,4- and 20% 2,6-isomer mixture) was added and heated with stirring for 2.5 hours 12O ⁰ C. The resulting prepolymer has an isocyanate content of 5 »6% (calculated 5.0 96) and a viscosity of 5680 centipoise at 25 ⁰ C

A mixture of 100 parts by weight of water and 20 parts by weight of the prepolymer prepared according to 3a) is placed in a beaker and a solution of 0.8 parts by weight of ethylenediamine in 100 parts by weight of water is added with thorough stirring with a mechanical stirrer. A water gel with a polymer content of 10 % and a compressive stress of 1.2 KPa (kilopascals) forms immediately after the 1st exposure at 20% total exposure. The gel can be repeatedly frozen by cooling and thawing by heating without losing its properties.

Example 4;

615 g of a trifunctional polyether started on glycerol, which contains 30 percent by weight propylene oxide and 70 percent by weight ethylene oxide units, has a hydroxyl number of 26.5 and a molecular weight of 6460, are placed in a flask, 185 g of hexa methylene diisocyanate are added and stirred for 6 hours 130 ⁰ C heated. The resulting prepolymer has an isocyanate content of 9.6 % (calculated 10.0 90 and a viscosity of 2900 centipoise at 25 ° C.

Le A 15 .210 - 15 -

5098 15/10 44

A mixture of 100 parts by weight of water and 20 parts by weight of the prepolymer prepared according to 4a) is placed in a beaker and a solution of 1.37 parts by weight of ethylenediamine in 100 parts by weight of water is added with thorough stirring with a mechanical stirrer. After 4 hours, a water gel with a polymer content of 10% forms, which at 20 % load has a compressive stress of 4.1 KPa (kilopascals) after the 1st load and is highly elastic.

A mixture of 100 parts by weight of methanol and 20 parts by weight of the prepolymer prepared according to 4a) is placed in a beaker and a solution of 1.37 parts by weight of ethylenediamine and 100 parts by weight of methanol is added with thorough stirring with a mechanical stirrer. After 25 seconds, a methanol gel with a polymer content of 10 % has formed, which is very stable.

Example 5:

590 g of a trifunctional polyether started on glycerol, which contains 55 percent by weight propylene oxide and 45 percent by weight ethylene oxide units, has a hydroxyl number of 56 and a molecular weight of 3000, are placed in a flask, 210 g of hexamethylene diisocyanate are added and the mixture is stirred for 4.5 hours at 120 ⁰ C heated. The resulting prepolymer has an isocyanate content of 10.2 (calculated 10.0 %) and a viscosity of 1670 centipoise at 25 ° C.

Le A 15 210 - 16 -

509815/1044

b) Manufacture of a water gel

A mixture of 100 parts by weight of water and 20 parts by weight of the prepolymer described under 5a) are placed in a beaker and a solution of 1.39 parts by weight of ethylenediamine in 100 parts by weight of water is added with thorough stirring with a mechanical stirrer. After 5 seconds, a water gel with a polymer content of 10 % has formed, which is highly elastic and at 20 % load has a compressive stress of 6.1 KPa (kilopascals) after the 1st load.

c) Manufacturing_a_ethanol_gel_

The procedure is as described in Example 5b), only that ethyl alcohol is used instead of water. After 29 seconds, an ethanol gel with a polymer content of 10 % has formed, which is highly elastic and stable.

Examples 6-8:

A mixture of 100 parts by weight of water and 15 parts by weight of the prepolymer prepared according to la) are placed in a beaker and brought together with thorough mechanical mixing with a solution of the amines given below in 100 parts by weight of water. After the reaction time given below, a stable water gel with a polymer content of around 7.5 % has formed.

Le A 15 210 - 17 -

Table 1

example A m i η Type Parts by weight reaction time 1,3-Dxaminomethylbenzene 1.28 (lake.) 6th Tetraethylene pentainine 0.71 2 7th Guanidine carbonate 1.13 1 8th 100

example 9z

Manufacturing_of_fiber_reinforced_gel

The preparation of the water gel described in Example 1 b) is repeated, but with sufficient cellulose powder being mixed into component B that 2.5 percent by weight of cellulose powder is present in the finished gel. After the two components have been mixed, the gel solidifies after around one second. A gel has then formed that is highly elastic and with a 20 % load a compressive stress of 6.8 KPa (kilopascals) after the. Has burden. The gel can be repeatedly frozen by cooling to -10 ⁰ C and thawed by heating, without losing its properties.

The examples in Table 2 below were carried out with a continuous working machine according to FIG. 1 executed.

Le A 15 210

- 18 -

509815 / ΊOAA

Table 2

Pre-polymer chain extension indicator liquid phase temperature pH des
play NCO medium NH ₅ / NCO (distilled gel at the outlet

% kg / h kg / h ^c H ₅ O) of the machine when
^d kg / h pe run

Fixed remarks substance content

5.13 30 ethylenediamine

(Dissolved twice in H ₃ O) *

1.2

406

25th

8-9

soft gel (dimensionally stable)

a 5.07

cn b O C. CO d CD

30th

450

25th

8-9

20 42.5

20 42.5

24 ethylenediamine 87.5

24

1.2
1.2
1.0 563
385
128 30th
30th
45 HOOCO
H I I
VOVO 1.0 156 45 11 (Water with 0.1%
Nutrient salt) 1.2 186 35 9-1 1.2 300 30th 9 1.1 372 35 8th

5.5

.3.3

4.7

10.5

8.9-

very soft, no longer completely homogeneous gel

solid rope

solid rope

a 2.3 15 ethylenediamine 29.5

(l # ig)
b 20 42.5

30th

5.8 soft strands

5.6 homogeneous gel

6.5 cut-resistant gel

a

30th

(Water with 0.1%
Nutrient salt)

58 1.1 372 45 8

b 5.13 30 ethylenediamine (2 * ig dissolved in H ₉ O) * 1.2 406

+ 1600 l / h air 25 8

6.5 cut-resistant gel

Foam gel

Le A 15 210

- 19 -

Claims (3)

Patent claims: ** · * '· 1, 'Process for the production of polyurethane polyurea gels by reacting prepolymers containing isocyanate groups with chain extenders in water
and / or alcohols, characterized in that reaction products of polyethers containing hydroxyl groups are used as prepolymers containing isocyanate groups
more than 40 percent by weight of ethylene oxide units
Polyisocyanates in an NC0 / 0H ratio greater than 1, and
used as chain extender di- or polyamines. 2. The method according to claim 1, characterized by the use of a centrifugal homogenizing machine for mixing of the components. 3. The method according to claim 1, characterized by the use a device with a countercurrent injection chamber for mixing the components. Le A 15 210 - 20 - 509 815/104 A