CH630530A5 - Bandaging material - Google Patents

Description

The present invention relates to a dressing material.

According to the state of the art, dressing materials consist of woven or knitted materials, which can also be combined with plastic films. Both natural and synthetic fibers are used to manufacture the woven or knitted fabrics. If inflammatory areas that require cooling are to be treated, it is customary to soak these dressings with water. Instead, you can also wet other woven or knitted materials such as rags, towels or handkerchiefs and thus 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; you also use wet towels or handkerchiefs that are wrapped around the calves. However, these methods generally have a number of disadvantages. It is particularly disadvantageous that only a very limited amount of water can be introduced into such textile materials, since otherwise the water will run out and thus wet the surrounding swelling.

It has now been found that the disadvantages inherent in the previous dressings can be eliminated,

if materials based on water-containing polyurethane urea gels are used as dressing materials.

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

The hydrogels and alcohol gels to be used according to the invention, based on polyurethane polyureas, are known in part from DOS 2,347,299. They are usually obtained by reacting prepolymers containing isocyanate groups from polyethers with at least 40% of ethylene oxide units with di- or polyamines or water as chain extenders in the presence of water and / or alcohols as dispersants and of fragrances and optionally other additives.

The term gel for such materials is generally intended to describe the physical nature of the jelly-like or jelly-like end product rather than the exact polymer-physical structure according to today's views of colloid chemistry about this state.

It has been found that dressings based on such gels, preferably polyurethane-polyurea hydrogels, generally offer a number of surprising advantages:

1. The water content in the gels can be greater than 90% by weight and any less. Here is the water

even at a content of 95% by weight, is still absolutely firmly bound in the polymer network and does not run out.

2. The gels are mechanically resilient; they can be stretched elastically, with good tear resistance being observed.

3. No syneresis occurs when the gels or bandages are standing. The water is immobilized so that the gel body can be viewed as if it consisted of solid water.

4. The gels or gel-containing dressings can be frozen at temperatures below the freezing point of the water without the structure being destroyed or damaged. Thawing and re-freezing can then take place reversibly. The process can be repeated any number of times.

5. During use, the gel or the gel-containing dressing material slowly releases water while cooling. The water lost in the process can be stored again in the polymer structure by storage in water, i.e. Water release and water absorption are reversible.

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

7. The gel masses can be easily profiled. In this way, both sheet-like structures and materials of any shape can be obtained. The latter procedure is particularly valuable when dressing materials are to be produced for those parts of the body that are difficult to wrap.

The dressing material according to the invention is characterized in that it consists at least in part of polyurethane urea gel containing water and / or alcohol.

The invention furthermore relates to a process for the preparation of the dressing material mentioned, which is characterized in that a mixture of a prepolymer, water and / or alcohol and isocyanate and urethane groups, prepared from organic polyisocyanate and polyether with at least 40% by weight of ethylene oxide units, and optionally polyamine by a polyaddition reaction between the. called prepolymer and water and / or polyamine as a chain extender in a water and / or alcohol-containing polyurethane urea gel and, before it has reacted, is placed on a support material or between support materials.

Suitable reaction media for the preparation of the gels are water and alcohols or mixtures of the two. The process products can therefore also be differentiated into hydrogels and alcohol gels. Alcohols usually include both volatile monoalcohols, such as ethanol, isopropanol or butanol, and low-volatility polyalcohols, such as e.g. Ethylene glycol, diethylene glycol, glycerin or trimethylolpropane. Preferred according to the invention are gels in which the dispersant consists of at least 50% by weight of water.

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The gels can be produced in various ways. For example, all components, i.e. to combine the prepolymer, the dispersant, ie water and / or alcohol, fragrances, medicinal preparations, the chain extender and optionally other additives in one shot. However, it is advisable to proceed in stages. The fragrances, the medicinal preparations and, if appropriate, further additives and, if appropriate, the crosslinking agents, such as polyamines, are normally dissolved in the dispersant. In parallel to this, an emulsion or solution of the prepolymer is usually prepared in the dispersant and the two are then mixed together, taking into account stoichiometric quantitative ratios. The mixture is expediently poured into molds or applied to textile or non-textile substrates; in any case, the reaction to the gel used as a dressing or as part of the dressing takes place in a few seconds to minutes.

The end product is usually compact or foam-like, depending on the chain extender used. If amines are used as chain extenders, compact gels usually result; If water is used, foam-like products are formed as a result of the parallel reaction of the isocyanate groups with the water to form gaseous carbon dioxide.

Intensive mixing of the starting component usually facilitates the manufacture of the dressing material gels and improves their quality.

In the simplest case, the mixing can take place in a zone of increased turbulence, which is caused by a mechanical stirring device. Better results are obtained, for example, from centrifugal homogenizing machines or from agitator mixing chambers of polyurethane foaming machines known from the literature or commercially available. However, intensive mixing can generally also be achieved by using the mixing devices of polyurethane foaming machines, in which the mixing takes place by countercurrent injection.

Before they harden, the gels can be cast or squeegee into endless, arbitrarily thick webs, which can also be profiled if necessary.

It is particularly advantageous if the gels are supported on carrier materials such as e.g. Fabrics, knitted fabrics, nonwovens, foils and nets based on natural and / or synthetic polymers, which may also be foam-like, may be applied. Foam-like carrier materials are particularly the known soft and semi-hard polyurethane foams. The thickness of the gel layers can vary within wide limits and depends essentially only 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 preparation of the gels from polyethers containing at least 40 wt an NCO / OH ratio greater than 1, preferably 1.5-20, particularly preferably 2-10.

The optimum ratio for carrying out the process normally depends 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 3.5 and 10% by weight.

Amines are used as chain extenders630530

det, essentially stoichiometric amounts of prepolymers and amine are required for the formation of the dressing material gels. When carrying out the process industrially, however, in order to achieve a suitable residence time in the mixing units, it has proven advantageous to work with an excess of the amine component, i.e. with an NH2 / NCO ratio greater than 1, preferably 1-1.2.

If water is used as a chain extender, the NC0 / H20 ratio can also be stoichiometrically equivalent. However, it is also possible, particularly in the production of foam-like gels, to use considerably more water than isocyanate group equivalence would require. It is even of particular advantage to use the water as a dispersing agent, so that foam-like hydrogels result. In this case, the water normally has a double function: firstly, it is a reaction component that reacts with the isocyanate groups and then also the dispersant.

In the formation of the gels, the amount of water and / or alcohol present is generally variable within a wide range 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 generally greatly influenced by the quantitative ratio between polymers and dispersants. In general, the gels become more stable and harder with increasing polymer content and softer and less structurally firm with decreasing polymer content up to the limit of about 2% by weight. The gels to be used according to the invention preferably contain about 30 to 95% by weight of water and / or alcohol.

It is particularly surprising that the gel-based dressings that can be produced according to the invention are normally extraordinarily stable. Even after prolonged storage, there is no visible phase separation in the gels, e.g. through a clouding of the material. The dimensional stability is retained even after storage at higher temperatures, with no phase separations usually being observed here either. The dispersant is very firmly bound in the gel, but can emerge more or less quickly depending on its vapor pressure, the gel body gradually shrinking in proportion to its outer dimensions. During this process, fragrances and medicinal preparations can diffuse out of the gel body and be released into the environment, for example the human skin. A further cooling effect occurs during the release of the dispersant, particularly in the case of water. The gel body is normally reversible in terms of dispersant delivery and uptake. This means that materials which have released part of their dispersing agent, as a rule, absorb it again when it is stored in the pure dispersing agent and incorporate it into the polymer structure.

It is also surprising that the gels can be frozen and thawed as often as required without destroying their structure. This is particularly advantageous, for example, when the water having a high heating or cooling capacity is used as the dispersing agent. The dressings that can be produced 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 preferably at least 2 active ethers with a polyether

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Molecular weight of 500-10,000, preferably 2000-8000, which contain at least 40 wt .-% of ethylene oxide groups. Such polyethers are normally made by reacting compounds with reactive hydrogen atoms, e.g. Polyalcohols, with ethylene oxide and optionally other alkylene oxides such as propylene oxide, butylene oxide, styrene oxide, epichlorohydrin or mixtures of these alkylene oxides.

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, 2-butynediol-1,4, glycerol, 2,4-butanediol, 1,3,6-hexanetriol, trimethylolpropane, resorcinol, hydroquinone, 4,6-di-tert-butylbenzate catechol, 3-hydroxy-2-naphthol, 6,7-di-hydroxy-l-naphthol , 2,5-dihydroxy-l-naphthol, 2,2-bis (p-hydroxyphenyl) propane, bis- (p-hydroxyphenyl) methane and a, a, fi) tris (hydroxyphenyl) alkanes such as, for example 1,1,2-tris (hydroxyphenyl) ethane or 1,3,3-tris (hydroxyphenyl) propane.

Other suitable polyethers are the 1,2-alkylene oxide derivatives of aliphatic or aromatic mono- or polyamines, e.g. Ammonia, methylamine, ethylenediamine, N, N-dimethylethylenediamine, tetra- or hexamethylenediamine, diethylenetriamine, ethanolamine, diethanolamine, oleyldiethanolamine, methyldiethanolamine, tri-ethanolamine, aminoethylpiperazine, o-, m- and p-phenamine , 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'-diaminodiphenyl-methane, 1-fluorenamine, 1,4-anthradiamine, 9,10-diaminophenate, or 4,4'-diaminoazobenzene. Resin-like materials of the phenol and resol type can also be used as starting molecules for the polyethers.

All of these polyethers are usually constructed using ethylene oxide.

As starting components to be used according to the invention, furthermore, aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic polyiso-cyanates, such as those described, B. by W. Siefken in Justus Liebigs Annalen der Chemie, 562, pages 75 to 136, for example 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, l-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (DAS 1202 785), 2, 4- and 2,6-hexahydrotolylene 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-l, 5-diisocyanate, triphenylmethane-4,4'-4 "-triisocyanate, polyphenyl-polymethylene-polyiso-cyanates, as obtained by aniline-formaldehyde condensation and subsequent phosgenation and, for example, in British Patents 874 4 30 and 848 671, perchlorinated aryl polyisocyanates, e.g. German Patent Specification 1,157,601 describes polyisocyanates containing carbodiimide groups, as described in German Patent 1,092,007, diisocyanates as described in American Patent 3,492,330, polyisocyanates containing allophanate groups according to British Patent 994,890, the Belgian patent specification 761 626 and the published Dutch patent application 7 102 524, polyisocyanates containing iso-cyanurate groups, such as, for example in German patents 1 022 789.1 222 067 and 1 027 394 and in German laid-open publications 1 929 034 and 2 004 048, polyisocyanates containing urethane groups, such as those described in e.g. described in Belgian patent specification 752 261 or in American patent specification 3 394 164, polyisocyanates containing acylated urea groups according to German patent specification 1 230 778, polyisocyanates containing biuret groups, such as those e.g. in German Patent 1 101 394, British Patent 889 050 and French Patent 7 017 514, polyisocyanates prepared by telomerization reactions, such as e.g. in Belgian patent 723,640, polyisocyanates containing ester groups, such as those e.g. in British Patents 956 474 and 1 072 956, in American Patent 3 567 763 and in German Patent 1 231 688 or reaction products of the above-mentioned isocyanates with acetals according to German Patent 1072385.

Aliphatic, cycloaliphatic or aromatic di- or polyamines are preferably used as the low molecular weight crosslinking agent or chain extender. Examples of such compounds are: ethylenediamine, hexamethylenediamine, diethylenetriamine, hydrazine, guanidine carbonate, N, N'-bis (3-aminopropyl) ethylenediamine, N, N'-bis (2-aminopropyl) ethylenediamine, N, N '-Bis- (2-aminoethyl) ethylenediamine, 4,4'-dimethylamino-diphenylmethane, 4,4-diamino-diphenylmethane, and 2,4- or. 2,6-diaminotoluene.

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

In the manufacture of the dressing materials, water-soluble and water-insoluble (i.e. water, optionally with the addition of dispersing agents, emulsifiable) additives can also be added to the gel batches to a considerable extent. Examples include hemostatic additives, a wide variety of medications, disinfectants, dyes, fragrances and cosmetic preparations that have an influence on the skin, for example regulating the skin's water balance. Other additives are, for example, natural or other synthetic gel formers, such as gelatin, carraghenates, alginates, polyvinyl alcohol and methyl cellulose.

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

In the production of the dressing material gels, the most varied fillers can also be added to a considerable extent (up to about 50% by volume), such as silicates, the most varied types of silica, aluminum oxides, the tin oxides, antimony trioxide, titanium dioxide, graphite and graphitized carbon, carbon black, Retort coal, flying sand, powdery cement types, a wide variety of inorganic and organic dye pigments, e.g. Iron oxide pigments, lead chromate, lead oxide and red lead. For example, short or long fibers made of natural or synthetic materials such as cellulose flour can also be used as fillers.

If the fillers are also used, it is advantageous, for example, that this delays the release of the dispersant, ie water and / or alcohol and the other additives, and thus extends the effectiveness of the dressing material until it is renewed.

Furthermore, it is generally possible to add a gaseous component (generally air) during the gel formation. It usually arises

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foam-like dressing material gels, the density (kg / m3) of which, depending on the amount of gas installed, is more or less reduced compared to the compact material.

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

For this purpose, the prepolymer containing NCO groups and, separately, the chain extender and the dispersing agent are continuously introduced into a mixing zone at a temperature above the melting point and below the decomposition point of NCO prepolymers and chain extender in such a flow rate that the isocyanate polyaddition in the mixing zone is preferably not yet completely completed. The still flowable or deformable, strongly water- or alcohol-containing polyurethane gel is then continuously removed from the mixing zone and, if necessary, then passed through a short residence time tube, which is provided with a profile mouthpiece, so that the resulting polyurethane dressing gel is normally used as formed endless strand, tape or plate goods.

The gel obtained can be used as such as a dressing. However, a combination with a carrier is expediently carried out. For this purpose, for example, the well-mixed gel mass is used continuously or discontinuously in conventional coating systems, e.g. by knife coating, brushing or watering on the textile or non-textile documents.

The dressings obtained can be brought to the market in open form. However, it is expedient for them to be welded into water vapor-impermeable films which can be opened if necessary. This assembly can also be carried out on standard welding machines.

The dressings obtained can be used for a wide variety of purposes in the medical and cosmetic fields. Examples include bandages against inflammatory swellings, calf wraps for lowering the body temperature of small children, wikel for local or general lowering of the body temperature, especially during operations on the hypothermic human body, face masks and ice packs.

example 1

a) Preparation of the prepolymer:

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

For this purpose, 1200 parts by weight of a polyether, which was obtained by the addition of 60% by weight of ethylene oxide and 40% by weight of propylene oxide to glycerol and which has a hydroxyl number of 28, are added dropwise with stirring within 3 hours. The reaction mixture is stirred at 80 ° C. for a further hour. 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) Production of the dressing:

7 parts by weight of the prepolymer described under a) are added to 59 parts by weight of water over the course of 3 seconds with mechanical stirring (stirring speed 1165 revolutions / min). After a stirring time of 50 seconds, the reaction mixture is poured into a mold.

The shape has an interior with the dimensions 25 cm x 8 cm x 0.5 cm. An 8 cm wide cotton fabric (gauze bandage, 34 g / m2) is placed lengthways on the 25 x 8 cm base, which protrudes 10 cm on both sides.

After 60 seconds from the start of mixing, the reaction sets in with slight foaming (start time). The setting time is 90 seconds. The blowing reaction is complete after 10 minutes. The molded body is removed from the mold after 5 minutes and sealed in an aluminum foil which is coated with polyethylene on the side facing the dressing material. The density of the gel body is 660 kg / m3.

The packaged dressing is stored at -20 ° C for 24 hours. Then the water in the dressing is allowed to thaw and return to room temperature. Even if this process is repeated several times, the usage properties of the dressing material are not changed.

Example 2

The procedure is exactly as in Example 1b, but instead of the cotton fabric, a fabric based on polyamide with a mesh size of 1 mm and a weight of 130 g / m2 is used.

Example 3

The procedure is exactly as in Example 1b, but instead of the cotton fabric, a fabric based on polyamide (130 g / m2) is used and a polyethylene film corresponding to the base area of the shape of 25 cm x 8 cm is placed on the reaction mixture at the start of the reaction in such a way that it is complete is covered by the polyethylene film.

Example 4

The procedure is exactly the same as in Example 1b, but instead of 59 parts by weight of water, an emulsion of 0.2 part by weight of the dye with the color index no. 42,085.3.5 parts by weight of a perfume oil (mixture of 60% by weight of isobornyl acetate and 40% by weight of the condensation product of 1 mol of nonylphenol and 10 mol of ethylene oxide) and 55.3 parts by weight of water.

Example 5

The procedure is exactly the same as in Example 1b, but instead of 49 parts by weight of water, an emulsion of 56 parts by weight of water and 3 parts by weight of a wound and burn ointment is used with the composition: Phenolum lique-factum 1 g, bismuth sabgallicum 5 g, Emplastrum Lithar-gyri 20 g, ointment base ad 100 g.

Example 6

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

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 of water and 13 parts by weight of propan-2-ol is used.

Example 8

The procedure is exactly the same as in Example 1b, but the reaction mixture used is a mixture of 9.5 parts by weight of the prepolymer described in Example la 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 has a density of 630 kg / m3.

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Example 9

The procedure is exactly the same as in Example 1b, but the reaction mixture used is a mixture of 9.5 parts by weight of the prepolymer described in Example la and 53.5 parts by weight of 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 is 45 seconds, the start time is 60 seconds and the setting time is 70 seconds. The density of the gel mass is 630 kg / m3.

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Claims (4)

630530 PATENT CLAIMS 1. dressing material, characterized in that it consists at least in part of water and / or alcohol-containing polyurethane urea gel. 2. Dressing material according to claim 1, characterized in that it contains one or more layers of a carrier material as an intermediate and / or cover layer. 3. A method for producing a dressing material according to claim 2, characterized in that a mixture of a prepolymer prepared from organic polyisocyanate and polyether with at least 40 weight percent ethylene oxide units, isocyanate and urethane groups, water and / or Alcohol and optionally polyamine are converted by a polyaddition reaction between the prepolymer mentioned and water and / or polyamine as a chain extender into a water and / or alcohol-containing polyurethane urea gel and, before it has reacted, is brought onto a support material or between support materials. 4. The method according to claim 3, characterized in that fragrances, medicinally active preparations or other additives are added to the mixture.