DE2538716A1 - DRESSES CONTAINING WATER - Google Patents

Description

The present invention relates to the production of novel dressing materials based on stable water-containing materials Polyurethane-urea gels.

According to the state of the art, bandages consist of woven or knitted materials, which are also made of plastic films can be combined. Both natural and synthetic fibers are used to manufacture the woven or knitted fabrics for use. If inflammatory swellings that require cooling are to be treated, it is common to to soak these bandages with water. Instead, you can use other woven or knitted materials, such as rags, Wet towels or handkerchiefs and use them to treat the inflammatory swellings. The same treatment is also common when high body temperatures, for example in infants and young children, are to be reduced; Here, too, wet towels or handkerchiefs are used, which are wrapped around the calves. However, these procedures have a number of disadvantages. A particular disadvantage is that only a very limited amount of water is used in such textile materials can bring in, otherwise the water will run out and wet the area around the swelling.

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It has now been found that the disadvantages adhering to previous dressing materials can be eliminated when used as dressing materials Materials based on water-containing polyurethane urea gels can be used.

The materials used according to the invention can thereby consist both of the gels alone and, preferably, of combinations with any desired carrier layers based on textile or non-textile products. The carrier layers can be coated with the polyurethane either on one side or on both sides be connected.

The hydrogels and alcohol gels to be used according to the invention based on polyurethane-polyureas are known in some cases from DOS 2,347,299. They are preserved through implementation of isocyanate group-containing prepolymers made from polyethers with at least 40% of ethylene oxide units with diamines or polyamines or water as a chain extender in the presence of water and / or alcohols as dispersants, as well as of fragrances and possibly other additives. The term gel for such materials, the aim is 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 it Reflect state.

It has been found that dressing materials based on such Gels, preferably polyurethane-polyurea hydrogels, offer a number of surprising advantages:

1. The water content in the gels can be greater than 90% by weight and any below. The water, even with a content of 95% by weight, is still absolutely solid in the polymer network bound and does not expire.

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2. The gels are mechanically resilient in a satisfactory manner; they can be stretched elastically, with good tear resistance is observed.

3. When the gels or bandages stand up, none occurs Syneresis a. The water is immobilized / so that the gel body can be viewed as if it were made of solid Water.

4. The gels or gel-containing dressings can be at temperatures Freeze below the freezing point of the water without destroying or damaging the structure. Can be reversible then thawing and refreezing take place again. The process can be repeated as often as you like.

5. During use, the water is released slowly with the effect of cooling from the gel or the gel-containing dressing material. That Water lost in the process can be stored in water again in the polymer structure, i.e. water is released and water absorption are reversible.

6. The gel masses can easily be combined with carrier materials. The good adhesion with flat textile structures is particularly noticeable.

7. The gel masses can be easily profiled. So can both sheet-like structures can be obtained as any designed materials in corresponding shapes. The latter Procedure is particularly valuable when dressing materials to be made for those parts of the body that are difficult to wrap around.

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The present patent application therefore relates to the use of polyurethane urea gels containing water and / or alcohols, which may also contain carrier, intermediate and / or cover layers, as dressing material.

The present patent application also relates to a method for the production of bandages containing water and / or alcohols based on polyurethane urea gels, the characterized in that prepolymers containing isocyanate groups and made of polyethers with at least 40% by weight of ethylene oxide units with water and / or polyamines as chain extenders in the presence of water and / or alcohols and possibly fragrances, medicinally active preparations and possibly further additives are mixed and the mixture prior to reacting, optionally with shaping, on or between carrier materials is applied.

Suitable reaction media for the preparation of the gels are water and alcohols or mixtures of both. The process products can therefore also be used in hydrogels and alcohol gels can be distinguished. Both volatile monoalcohols, such as ethanol, isopropanol or butanol, can be used as alcohols in question, as well as non-volatile polyalcohols such as ethylene glycol, Diethylene glycol, glycerine, or trimethylol propane. According to the invention Gels in which the dispersant consists of at least 50% by weight of water are preferred.

The gels can be produced in various ways. So it is possible to use all components, i.e. the prepolymer, the dispersant, i.e. water and / or alcohol, fragrances, medical preparations, the chain lengthening agent and possibly to combine other additives in one shot. Appropriately, however, one proceeds in stages. The fragrances that medi-

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Zinischen preparations and optionally other additives and optionally the crosslinking agents, such as polyamines, are in the dispersant dissolved. In parallel, an emulsion or solution of the prepolymer in the dispersant is prepared and then both taking into account stoichiometric proportions mixed together. The mixture is poured into molds or applied to textile or non-textile carrier materials; in in any case, the reaction to the gel, which is used as a dressing material or as part of the dressing material, takes place in a few Seconds to minutes.

The end product depends on the chain modifier used compact or foam-like. If amines are used as chain extenders, compact gels result; becomes water are used, as a result of the parallel reaction of the isocyanate groups with the water to form gaseous Carbon dioxide foam-like products.

Intensive mixing of the starting components facilitates the manufacture of the bandages and their quality improved.

In the simplest case, the mixing can take place in a zone of increased turbulence caused by a mechanical stirring device will take place. Better results are obtained when using fast-running 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 where mixing is done by countercurrent injection.

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Before they harden, the gels can be poured or lolled into endless strips of any thickness, which may be additionally profiled can be.

It is particularly advantageous if the gels are placed on carrier materials, such as woven, knitted fabrics, fleeces, foils, before they harden and nets based on natural and / or synthetic polymers, which may also have a foam-like nature, are applied will. Foam-like carrier materials are particularly the known soft and semi-rigid polyurethane foams. The fat the gel layers can vary within wide limits and essentially only depends on the requirements placed on the dressing material. In general, the thickness of the gel layers is between 1 and 50 mm.

The prepolymers used for the production of the gels from polyethers containing at least 40% by weight ethylene oxide and the higher-functional polyisocyanates, which are still terminally contain free isocyanate groups, by reacting the corresponding polyethers with an excess amount of polyisocyanate, that is, 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 and the functionality and the structure of the polyether. In general, the isocyanate levels should of the prepolymers are between 2 and 20% by weight, preferably between 3.5 and 10% by weight.

If amines are used as chain extenders, then essentially stoichiometric gels are used for the formation of the dressing material Amounts of prepolymer and amine required. In terms of the technical implementation of the process, however, it has to be a to achieve suitable residence time in the mixing units than

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Proven advantageous to work with an excess of the amine component, ie with eil
preferably from 1 - 1.2,

to work, ie with an NH ₂ / NCO ratio greater than 1,

If water is used as a chain extender, the NCO / H ₂ O ratio can also be stoichiometrically equivalent here. However, it is also possible, particularly when producing gels in the form of a foam, to use significantly more water than the isocyanate group equivalence would require. It is then even of particular advantage to also use the water as a dispersant, so that foam-like hydrogels result. In this case the water has a double puncture. On the one hand, it is the reaction component that reacts with the isocyanate groups and then also the dispersant.

When the gels are formed, the amount of water and / or alcohol present is variable within wide limits and is not critical. Based the weight of alcohol and / or water can be up to 98% of the total mass of the gel. By the proportion between Polymers ™ and dispersants, however, the properties strongly influenced the gels obtained. In general, the more the polymer content increases, the more stable and harder the gels become and with decreasing polymer content up to the limit of about 2% by weight, it becomes softer and less structurally stable. Preferably included the gels to be used according to the invention contain about 30 to 95% by weight of water and / or alcohol.

It is particularly surprising that the gel-based bandages according to the invention are extremely stable. Even after If the gels are stored for a longer period of time, there is no visible phase separation, which can be caused, for example, by the material becoming cloudy would make noticeable. Even after storage at higher levels

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Temperatures, the dimensional stability is retained, and also no phase separations can be observed here. The dispersant is very tightly bound in the gel, but can emerge more or less quickly depending on its vapor pressure, whereby the gel body gradually shrinks in proportion to its external dimensions. During this process you can use fragrances and medicinal Preparations diffuse out of the gel body and released into the environment, for example human skin will. A further cooling effect occurs during the release of the dispersant, in particular in the case of water. In terms of The gel body is reversible to the dispersant release and uptake. That means that such materials are a part have given up their dispersant, take it up again when stored in the pure dispersant and in install the polymer framework.

It is also surprising that the gels without their destruction Structure can be frozen and thawed again as often as required. This is particularly advantageous when used as a dispersant the water, which has a high heating or cooling capacity, is used. The dressing materials according to the invention can therefore be safely stored in refrigerators or freezers until they are used.

The starting material for the gels to be used according to the invention are polyethers containing at least 2 active hydrogen atoms with a molecular weight of 500-10,000, preferably 2000-8000, which contain at least 40% by weight of ethylene oxide groups. Such polyethers are made by reacting compounds with reactive hydrogen atoms, such as polyalcohols, with ethylene oxide and optionally other alkylene oxides such as propylene oxide, butylene oxide, styrene oxide, epichlorohydrin or Mixtures of these alkylene oxides produced.

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Suitable polyhydric alcohols and phenols are for example ethylene glycol, diethylene glycol, polyethylene glycol / 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, decanediol-1, 2, butyn-2-diol-1, 4, glycerol, butanediol-2,4, hexanetriol-1,3,6, trimethylolpropane, resorcinol, hydroquinone, 4,6-di-tert-butylbenzatechol, 3-hydroxy-2-naphthol, 6,7-dihydroxy-1 -naphthol, 2,5-dihydroxy-l-naphthol, 2,2-bis (p-hydroxyphenyl) propane, bis- (p-hydroxyphenyl) methane and oC, cC, c <y, -Tris (hydroxyphenyl) - alkanes such as 1,1,2-tris- (hydroxyphenyl) -ethane or 1,1,3-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, Ν, Ν-dimethylethylenediamine, Tetra- or hexamethylenediamine, diethylenetriamine, ethanolamine, diethanolamine, oleyldiethanolamine, methyldiethanolamine, Triethanolamine, aminoethylpiperazine, o-, m- and p-phenylenediamine, 2,4- and 2,6-diaminotoluene, 2,6-diamino-p-xylene, and polynuclear and condensed aromatic polyamines such as 1,4-naphthylenediamine, 1,5-naphthylenediamine, benzidine, toluidine, 2,2-dichloro-4,4'-diaminodiphenylmethane, 1-fluorenamine, 1,4 anthradiamine, 9,10-diaminophenantrene, or 4,4'-diaminoazobenzene. As starting molecules of the polyethers, resinous materials of the phenolic and resol types are also suitable.

All of these polyethers are built up using ethylene oxide.

The starting components to be used according to the invention are also aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic polyisocyanates, such as those described by W. Siefken in Justus Liebig's Annalen der Chemie, 562, pages 75 to 136, are described, for example ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexa-

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methylene diisocyanate,!, ^ - dodecane diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3- and 1,4-diisocyanate and any mixtures of these isomers, i-isocyanato-S / S / S-trimethyl-S-isocyanatomethyl -cyclohexane (DAS 1.202.785), 2,4- and 2,6-hexahydrotoluylene diisocyanate and 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 diisocyanate and any mixtures of these isomers, diphenylmethane-2,4'- and / or -4,4'-diisocyanate, naphthylene-1,5-diisocyanate, triphenylmethane-4,4 ^l -4 "-triisocyanate, polyphenyl-polymethylene-polyisocyanate, as obtained by aniline-formaldehyde condensation and subsequent phosgenation and, for example, in British patents 874 430 and 848 671, perchlorinated aryl polyisocyanates, as described, for example, in German Auslegeschrift 1,157,601, polyiso containing carbodiimide groups cyanates, as they are described in the German patent specification 1.092.007, diisocyanates, as they are described in the American patent specification 3.492.330, polyisocyanates containing allophanate groups according to the British patent specification 994.890, the Belgian patent specification 761.626 and the published Dutch patent application 7.102.524, Polyisocyanates containing isocyanurate groups, such as those described, for example, in German patents 1,022. 789, 1.222.067 and 1.O27.394 and in the German Offenlegungsschriften 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, are acylated Polyisocyanates containing urea groups according to German Patent 1.230.778, polyisocyanates containing biuret groups, as described, for example, in German Patent 1.101.394, British Patent 889.050 and French Patent 7.017.514

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are polyisocyanates produced by telomerization reactions, as described e.g. in Belgian patent specification 723.640. Polyisocyanates containing ester groups, as for example in the British patents 956,474 and 1,072,956, in the American patent 3,567,763 and are mentioned in German Patent 1.231.688 or reaction products of the above-mentioned isocyanates with acetals according to the German patent specification T.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'-bis- (3-aminopropyl) -ethylenediamine , Ν, Ν ^1- bis (2-aminopropyl) -ethylenediamine, Ν, Ν'-bis- (2-aminoethyl) -ethylenediamine, 4,4'-dimethylamino-diphenylmethane, 4.4 ^l -diamino-diphenyl-methane , as well as 2,4- and 2,6-diamihotoluene.

The production of prepolymers from the polyethers and the Polyisocyanates are carried out according to known processes, with NCO / OH ratios set greater than 1.

In the manufacture of the dressing materials can, also to a considerable extent Extent of water-soluble and water-insoluble (i.e. in water if necessary with the addition of dispersants, emulsifiable) additives are added to the gel batches. Examples of this are around .Hemostatic additives, various kinds of medication, Disinfectants, dyes, fragrances and cosmetic Preparations which have an influence on the skin, for example regulate the water balance of the skin. Other additives are natural or other synthetic gel formers, such as gelatin, carraghenate, alginates, polyvinyl alcohol and methyl cellulose.

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All of these additives can be added to the gel masses in amounts of up to about 20% by volume.

The most varied of types can also be used to a considerable extent (up to about 50% by volume) in the production of the dressing material gels Fillers are added, such as silicates, various types of silica, aluminum oxides, tin oxides, antimony trioxide, Titanium dioxide, graphite and graphitized coal, soot, retort carbon, drifting sand, powdery types of cement, the most diverse inorganic and organic dye pigments, e.g. Iron oxide pigments, lead chromate, lead oxide and red lead. Short or long fibers made of natural or natural fibers can also be used as fillers Use synthetic materials such as pulp flour.

If the fillers are also used, it is advantageous that this results in the release of the dispersant, that is to say of water and / or alcohol and the other additives is delayed and so the effectiveness of the dressing material until it is renewed is extended.

It is also possible to use a gaseous gel during gel formation Add component (generally air). This creates foam-like dressing gels with a density (kg / m) Depending on the amount of gas installed, it is more or less reduced compared to the compact material.

A particular advantage of the method according to the invention is that it can very easily be made continuous.

The prepolymers containing NCO groups and separately therefrom the Chain extenders 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 in such a mass flow continuously in

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a mixing zone introduced so that the isocyanate polyaddition is not yet fully completed in the mixing zone. That still Flowable or deformable polyurethane gel with a high water or alcohol content is then continuously removed from the mixing zone and if necessary then passed through a short dwell tube, which is provided with a profile mouthpiece, so that the The resulting polyurethane bandage gel is obtained as molded endless strand, tape or sheet goods.

The gel obtained can be used as such as a dressing material. Appropriately, however, there is a combination with one Carrier. For this purpose, the well mixed gel mass is used in the usual Continuous or discontinuous coating systems, e.g. by knife-coating, brushing or pouring with the textlien or connected to non-textile documents.

The bandages obtained can be placed on the market in open form. However, welding is expediently carried out in foils that are impermeable to water vapor and can be opened if necessary. This assembly can also be done on the commercially available automatic welding machines.

The bandages obtained can be used for the most diverse Purposes in the medical and cosmetic field are used. Examples are dressings against inflammatory swellings, Calf wraps for lowering the body temperature of small children, wraps for local or general lowering the body temperature, especially during operations on the hypothermic human body, face masks and ice packs.

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example 1

a) Preparation of the prepolymer:

159 parts by weight of tolylene diisocyanate are placed in a reaction vessel (80% 2,4- and 20% 2,6-isomer) heated to 80 ° C.

For this purpose, 1200 parts by weight are added within 3 hours with stirring a polyether added dropwise / the by addition of 60% by weight of ethylene oxide and 40% by weight of propylene oxide of glycerol and which has a hydroxyl number of 28. The reaction mixture becomes another at 80.degree Hour stirred. It is then allowed to cool to room temperature with stirring. The prepolymer obtained has an isocyanate content of 4.2% by weight and a viscosity of 5200 centipoise at 25 ° C.

b) Manufacture of the dressing material:

To 59 parts by weight of water verden 7 parts by weight of the under a) the prepolymers described within 3 seconds with mechanical stirring (stirring speed 1165 revolutions / min.) admitted. After 50 seconds of stirring, the reaction mixture is poured into a mold.

The shape has an interior with the dimensions 25 cm 8 cm χ 0.5 cm. There is an 8 cm on the 25 cm χ 8 cm base

2 wide cotton fabrics (gauze bandage, 34 g / m) lengthways inserted that protrudes 10 cm on both sides.

After 60 seconds from the start of mixing, the reaction begins with slight foaming (start time). The setting time is 90 seconds. After 10 minutes there is the blowing reaction

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completed. The molding is removed from the mold after 5 minutes and in an aluminum foil which is coated with polyethylene on the side facing the bandage material.

3 The density of the gel body is 660 kg / m.

The packaged bandage material is stored at -20 ° C for 24 hours. The water in the bandage is then allowed to thaw and return to room temperature. Also at Repeating this process several times does not change the properties of the dressing material.

Example 2

The procedure is exactly as in Example 1b, but instead of the cotton fabric, a fabric based on polyamide is also used

a mesh size of 1 mm and a weight of 130 g / m.

Example 3

The procedure is exactly as in Example 1b, used instead of the Cotton fabric, however, a fabric based on polyamide

2
(130 g / m) and, at the start of the reaction, place a polyethylene film corresponding to the base area of the mold of 25 cm 8 cm on the reaction mixture in such a way that it is completely covered by the polyethylene film.

Example 4

The procedure is exactly as in Example 1b, but instead of 59 parts by weight of water, an emulsion of 0.2 parts by weight

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dividing the dye with the color index no. 42 085, 3.5 parts by weight a perfume oil (mixture of 60% by weight isobornyl acetate and 40% by weight of the condensation product 1 mole of Nony! Phenol and 10 moles of ethylene oxide) and 55.3 parts by weight of water.

Example 5

The procedure is exactly as in Example 1b, used instead of 59 parts by weight of water, however, an emulsion of 56 parts by weight of water and 3 parts by weight of a wound and burn ointment with the composition: Phenolum liquefaction 1g, Bismutum sabgallicum 5g, Emplastrum Lithargyri 20g, ointment base ad 100g.

Example 6

The procedure is exactly as in Example 1b, used instead of 59 parts by weight of water, however, a suspension of 55 parts by weight of water and 4 parts by weight of powdered titanium dioxide.

Example 7

The procedure is exactly as in Example 1b, but instead of 59 parts by weight of water, a mixture of 46 parts by weight is used Water and 13 parts by weight propan-2-ol.

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Example 8

The procedure is exactly as in Example 1b, but a mixture of 9.5 parts by weight of that in Example is used as the reaction mixture 1a and 53.5 parts by weight of a solution consisting of 52 parts by weight of water and 1.5 parts by weight of the aluminum salt of acetic acid. The gel mass

3
has a density of 63O kg / m.

Example 9

The procedure is exactly as in Example 1b, but a mixture of 9.5 parts by weight of that in the example is used as the reaction mixture 1a described prepolymers and 53.5 parts by weight a mixture of 52 parts by weight of water and 1.5 parts by weight of menthol. From the start of mixing of the two reactants: the stirring time 45 seconds, the start time 60 Seconds and the setting time 70 seconds. The density of the gel mass is 630 kg / m.

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Claims (2)

Patent claims 1. Use of water and / or containing alcohol Polyurethane urea gels, which may contain carrier, intermediate and / or contain cover layers as dressing material. 2) Process for the production of bandages containing water and / or alcohols based on polyurethane urea gels, characterized in that isocyanate groups containing prepolymers of polyethers with at least 40 % By weight of ethylene oxide units with water and / or polyamines as chain extenders in the presence of water and / or alcohols, and optionally fragrances, medicinally active preparations and optionally further additives are mixed and the mixture before reacting, possibly with shaping, on or between carrier materials is applied. Le A 16 684 - 18 - 709810/0543