JPS5915653B2 - bandage material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the production of novel dressings based on stable polyurethaneurea gels containing water.

Bandages according to the current state of the art consist of woven or knitted fabrics which can also be combined with plastic sheets.

Both natural and synthetic fibers can be used in the production of woven or knitted fabrics.

Bandages that need to have a cooling effect for the treatment of inflammatory swellings are usually soaked in water, but such swellings are also treated with damp towels, handkerchiefs or other woven or knitted fabrics instead of bandages. The same treatment methods can also be used to lower high body temperatures in infants and small children, for example.

In that case, a damp towel or handkerchief is wrapped around the patient's calf.

This procedure has a number of drawbacks, the main one being that fabrics of the above type only retain a very limited amount of water and excess water drips from the bandage and wets the surrounding area.

It has been discovered that the disadvantages of conventionally used bandages can be overcome by using bandages made of materials based on aqueous polyurethaneurea gels.

The material used according to the invention can consist of a gel alone or advantageously of a combination of a gel and an optional support layer based on a textile or non-woven material.

These support layers may be bonded to the polyurethane on one or both sides.

The hydrogels and alcohol gels to be used according to the invention are based on polyurethane polyureas and have been partially already disclosed in DE-A-2347299.

These gels are made by incyanate prepolymers of polyethers containing at least 40% by weight of ethylene oxide units with water and/or alcohol as dispersants and in the presence of fragrances and optionally other additives as chain extenders. Obtained by reacting with diamine or higher polyamine or water.

The term "gel" as used in this specification refers to the physical properties of the gel-like end product rather than the precise physical structure of the polymer according to current views of colloid chemistry.

It has been discovered that bandages based on such gels, preferably polyurethane polyurea hydrogels, have a number of surprising advantages, including: (1) The water content in the gel is greater than 90% by weight; It can also have any value less than or equal to the numerical value.

This water is completely fixed within the polymer network and does not migrate out of the gel even at a water content of 95% by weight.

(2) This gel is also mechanically strong and elastically stretchable.

These gels were discovered to have high ultimate tensile strength.

(3) Syneresis (syneresis) does not occur even if the gel or bandage is left untreated.

Since the water is fixed, this gel may be considered to consist of 6 solid water''.

(4) This gel or a dressing containing this gel can also be frozen at temperatures below the freezing point of water without disruption or damage to the gel structure.

Freezing is reversible and thawing and refreezing can be repeated indefinitely.

(5) When this bandage is used, a cooling effect occurs and water is gradually liberated from the gel or bandage.

The water lost in this process can be returned to the polymer structure by leaving the gel or bandage in water, ie the release and absorption of water is reversible.

(6) This gel product can be easily combined with support materials.

One particularly notable feature is the tight bond obtained between the gel and the textile sheet.

(7) This gel mass can be easily molded.

These are obtained as flat structures and can also be converted into the desired shape in suitable molds.

This shaping is particularly useful when bandages are required for treatment of body parts that are difficult to bandage using conventional methods.

The invention therefore relates to the use of a polyurethaneurea gel containing water and/or alcohol and optionally comprising a support layer, an intermediate layer and/or a covering layer as a dressing.

The invention also relates to a method for producing a dressing based on a polyurethaneurea gel containing water and/or alcohol, which method comprises inocyanate group-containing prepolymers obtained from polyethers containing at least 40% by weight of ethylene oxide units. are mixed with water and/or polyamines as chain extenders in the presence of water and/or alcohol and optionally in the presence of fragrances, straw materials and other additives, and then the resulting mixture It is characterized in that it is applied to the layers of support material or between the layers of support material before the reaction of the components is complete, and that this operating procedure may optionally be accompanied by a shaping step.

Water or alcohol or mixtures thereof can be used to form the gel.

The products of this method are therefore divided into hydrogels and alcohol gels.

The alcohol used may be a readily volatile monohydric alcohol, such as ethanol, impropatol or butanol, or a relatively fixed polyhydric alcohol, such as ethylene glycol, diethylene glycol, glycerol or trimethylolpropane.

In preferred gels according to the invention, at least 50% by weight of the dispersant consists of water.

The preparation of this gel can be carried out in various ways, e.g. all components i.e. prepolymer, dispersant i.e. water and/or
Alternatively, the alcohol, fragrance, drug, chain extender, and other additives can be added all at once, but it is preferable to add these in stages.

In that case, perfumes, straw materials and other additives as well as crosslinking agents, if used, such as polyamines, are dissolved in the dispersant.

Simultaneously, an emulsion or solution of the prepolymer in a dispersant is made and the two batches are then mixed in the appropriate stoichiometric proportions.

The resulting mixture is poured into a mold or applied to a textile or non-textile support material.

Whichever procedure is employed, the reaction that produces the bandage or gel used as part of the bandage occurs within seconds or minutes.

The final product obtained can be a bubble-free solid or a foam depending on the chain extender used.

When amines are used as chain extenders, bubble-free gels are obtained; however, when water is used, the reaction of the accompanying incyanate groups with water produces gaseous carbon oxides, resulting in poor product performance. Become a foam.

Vigorous mixing of the starting components facilitates gel formation and improves gel properties.

In the simplest case, mixing may take place in a region of high turbulence produced by a mechanical stirrer.

Better results are obtained using high speed mixing devices such as impeller homogenizers or mixing chambers with agitators of the type described in the literature and used in commercial polyurethane foam machines.

Intensive mixing may also be carried out with the aid of a mixing device of a polyurethane foam machine, in which the components are mixed by countercurrent jetting.

The gel can be cast or spread to produce endless webs of desired thickness before being crosslinked, and these webs can be molded if desired.

It is particularly advantageous to apply the gel to the support material before it is crosslinked.

These supporting materials may consist of woven or knitted fabrics, non-woven webs, foils or mesh fabrics based on natural and/or synthetic polymers, and they may also have a foam structure.

Suitable foams for use as support materials are in particular the well-known flexible and semi-rigid polyurethane foams.

The thickness of the gel layer can vary within wide limits and depends fundamentally only on the requirements of the dressing.

Usually the thickness of the gel layer is between 1 and 50 mm.

The prepolymer used for gel formation consists of a polyether containing at least 40% by weight of ethylene oxide and a highly functional polyisocyanate that still contains free incyanate end groups. By reacting with isocyanate, i.e. 1:
It is made by using an isocyanate:hydroxyl ratio of greater than 1, preferably from 1.5:1 to 20:1, more optimally from 2:1 to 10:1.

The optimum ratio for carrying out this method is the molecular weight of the polyether,
Depends on functionality and structure.

The incyanate content of the prepolymer is usually between 2 and 20.
% by weight, preferably 35 to 10% by weight.

If the amine is used as a chain extender, it is necessary that the prepolymer and amine be used in essentially stoichiometric amounts to make the dressing gel, but this method cannot be used on an industrial scale. When carried out, an excess of the amine component is used in order to obtain a suitable residence time of the reactants in the mixing apparatus, i.e. greater than 1:1 and preferably from 1:1 to 1.2:1 NF2: It has been found advantageous to use the NCO ratio.

If water is used as a chain extender, the isocyanate groups and water may also be used in stoichiometric equivalent proportions;
Substantially more water is used as desired and especially in producing foam gels.

In that case, it is also particularly advantageous to use water as dispersant, so that hydrogels are obtained in the form of foams.

The water in that case serves a dual function, firstly as a reactant reacting with the incyanate groups and secondly as a dispersant.

The amount of water and/or alcohol present when the gel is being formed can vary within wide limits and is not critical.

The weight of alcohol and/or water may be up to 98% based on the total weight of the gel.

However, the properties of the resulting gels are strongly influenced by the ratio of polymer to dispersant.

In general, the resulting gel becomes progressively more stable and stiffer as the polymer content is increased, and becomes softer and structurally less rigid as the polymer content is reduced to a lower limit of about 2% by weight.

The gel used according to the invention preferably has a
Contains 5% by weight of water and/or alcohol.

It is particularly surprising that the gel-based dressings according to the invention are so stable.

Even after long-term storage, this gel does not undergo visible phase separation, which is noticeable by substances that become cloudy, for example.

Dimensional stability is maintained even when the gel is stored at high temperatures, yet no visible phase separation is observed.

The dispersant is very tightly fixed in the gel, but according to its vapor pressure it is suddenly released from the gel and the body of the gel gradually shrinks in proportion to its external dimensions.

At this stage, perfume and agglomerate may also be released from the gel and diffuse into the surrounding area of the gel, such as the patient's skin.

This release of dispersant results in additional cooling, especially when the dispersant is water.

The release of the dispersant from the gel and the reabsorption of the dispersant into the gel are reversible.

This means that if the gel loses some dispersant, it can reabsorb new dispersant, and if the gel is stored in pure dispersant, it can incorporate the dispersant into the polymer structure. means.

Another surprising feature of this gel is that it can be repeatedly frozen and thawed many times without destroying its structure.

This property is particularly advantageous when water is used as a dispersant due to its high heat capacity or cooling capacity.

The bandage according to the invention can therefore be stored indefinitely in a refrigerator or cooling room until needed.

The starting material required for the gel used in the present invention has a molecular weight of 50
0 to 10,000, preferably 2,000 to 8,000, which polyethers have at least 2 active hydrogen atoms and contain at least 40% by weight of ethylene oxide groups.

Polyethers of this type contain compounds containing reactive hydrogen atoms, such as polyhydric alcohols, ethylene oxide and optionally other alkylene oxides such as propylene oxide, butylene oxide, styrene oxide, epichlorohydrin or mixtures of these alkylene oxides. It is produced by reacting.

The following are examples of suitable polyhydric alcohols and phenols: ethylene glycol, diethylene glycol, polyethylene glycol, furopane-1,2-diol, propane-1,3-diol, butane-1,4-diol, hexane-1,2-diol. 1,6-diol, decane-1,2-diol, butyne-2-diol-(1,4), glycerol, butane-2,4-diol, hexane-L3,6-
Doliol, trimethylol-propane, resorcinol, hydroquinone, 4,6-di-tert-butylpyrocatechol, 3-oxy-2-naphthol, 6,7-cyoxy-1-naphthol, 2,5-dioxy-1-naphthol, 2,2-bis-(p-oxyphenyl)-propane, bis-(p-oxyphenyl)-methane and α, α,
ω-tris(oxyphenyl)-alkane e.g. 1,
1,2-tris-(oxyphenyl)-ethane or 1,
1,3-tris-(oxyphenyl)-propane.

Other suitable polyethers include aliphatic or aromatic mono- or polyamines such as ammonia, methylamine, ethylenediamine, N,N-dimethylethylenediamine, tetramethylenediamine or hexamethylenediamine, diethylenetriamine, ethanolamine, jetanolamine, oleyl glycol. Tanolamine, methyljetanolamine, triethanolamine, aminoethylhyherazine, o, m and p flurenamine, 24-diaminotoluene and 2,6-diaminotoluene, 2,6-
Cyamitsu-p-xylene and polynuclear and condensed aromatic polyamines such as 1,4-naphthylenediamine, 1,5-
naphthylene diamine, benzidine, toluidine, 2,2
-dichloro-4,4'-diaminodiphenylmethane, 1
-Fluorenamine, 1,4-anthodiamine, 9.
There are 1,2-alkylene oxide derivatives of 10-diaminophenanthrene and 4,4 diaminoazobenzene.

Resin materials such as phenols and resols may also be used as starting molecules for polyethers.

Ethylene oxide is included in the synthesis of all these polyethers.

The starting components used in the invention are also described, for example, by Justus Liebigs Annalen de
r Chemie.

Aliphatic, cycloaliphatic, aromatic aliphatic of the type described by W. 5iefken, 562, pp. 75-136;
Includes aromatic and heterocyclic polyisocyanates.

The following are examples of these: ethylene diisocyanate, tetra-methylene-1°4-diisocyanate, hexamethylene-1,6-diisocyanate, dodecane-1,6-diisocyanate.
1,12-diisocyanate, cyclobutane-1,3-
Diisocyanate, cyclohexane-1,3-diisocyanate and cyclohexane-1,4-diisocyanate and mixtures of these isomers, ■-Incyanato 3
．． 3.5-trimethyl-5-incyanato-methyl-
Cyclohexane (German Application No. 1202785), hexahydrotolylene-2,4-diisocyanate and hexahydrotolylene-2,6-diisocyanate and mixtures of these isomers, hexahydrophenylene-
1°3- and/or -1,4-diisocyanate, perhydrodiphenylmethane-2,4'- and/or -4,
4'-diisocyanate, ferrene-1,3- and -
1,4-diincyanate, tolylene-2,4-diisocyanate and tolylene-2,6-diisocyanate and mixtures of these isomers, diphenylmethane-2,4'
- and/or -4,4'-diisocyanate, naphthylene-1,5-diisocyanate, triphenylmethane-
It is obtained by condensing 4,4',4''-triisocyanate with aniline-formaldehyde and then phosgenation, for example, British Patent Nos. 874,430 and 8.
48671, for example the perchlorinated aryl polyisocyanates described in DE 1157601, carbodiimide groups as described in DE 1092007. Containing polyisocyanates, the diisocyanates described in US Pat. No. 3,492,330, US Pat. No. 994,890, Belgian Patent No. 761,626 and Dutch Patent Application Publication No. 7
102524, such as German Patent No. 1'022789;
Specifications No. 222067 and No. 1027394 and West German Published Application No. 1929034 and No. 200404
8, such as the urethane group-containing polyisocyanates described in Belgian Patent No. 752,261 or US Pat. No. 3,394,164, West German Patent No. 1230
Acylated urea group-containing polyisocyanates according to No. 778, such as German Patent No. 1101394, British Patent No. 889050 and French Patent No. 7017
514, such as those described in Belgian Patent No. 723,640, polyisocyanates made by telomerization reactions, such as British Patents No. 956,474 and British Patent No. 1,072,956. Specification, U.S. Patent No. 35677
63 and DE 1231688 and the reaction products of said incynates with acetals according to DE 1072385.

The low molecular weight crosslinkers or chain extenders used are aliphatic,
Alicyclic or aromatic diamines or higher polyamines such as ethylene diamine, hexamethylene diamine, diethylene triamine, hydrazine, guanidine carbonate, N, N
'-Bis-(3-aminopropyl)-ethylenediamine, N,N'-bis-(2-aminopropyl)-ethylenediamine, N,N'-bis-(2-amineethyl)-ethylenediamine, 4,4'-dimethyl Amino-diphenylmethane, 4,4'-diamino-diphenyl-methane and 2,4-diaminotoluene and 2,6-diaminotoluene may also be used.

The preparation of prepolymers from polyethers and polyisocyanates is carried out by known methods using NCO:OH ratios greater than 1:1.

Substantial amounts of water-soluble and water-insoluble additives (i.e., additives that can be emulsified in water with the addition of dispersants if desired) are added to the reaction mixture to make the gel used in the manufacture of the dressing. good.

Examples of suitable additives are hemostatic agents, various drugs, disinfectants, dyes, perfumes and dermatological cosmetics, for example for regulating the moisture content of the skin.

Other suitable additives include natural or synthetic gel-forming agents such as gelatin, carrgeenat, etc.
es), alginate, polyvinyl alcohol and methylcellulose.

All these additives may be added to the gel composition in amounts up to 20% by volume.

Equivalent amounts (up to 50% by volume) of various fillers may be added to the gel preparation, including, for example, silicates obtained from various silicides, aluminum oxide, tin oxide. , antimony trioxide, titanium dioxide, graphite and graphite carbon, carbon black, retort carbon, air-borne sand
5and), fine powder cement and various inorganic and organic dye pigments such as iron oxide pigments, lead chromate,
Contains lead oxide and red lead.

Short or long fibers of natural or synthetic materials, such as powdered cellulose, may also be used as fillers.

One of the advantages of using a filler is that the filler slows the release of dispersants, i.e. water and/or alcohol and other additives, reducing the amount of time the dressing can be left on the patient before it needs to be renewed. It is to prolong the

If desired, a gaseous component (usually air) may be added to the reaction mixture during gel formation.

This results in a gel dressing with a foamed structure, the unit weight (kV'm'') of which is essentially lower than the unit weight of the non-cellular material, depending on the amount of gas incorporated.

One particular advantage of the method according to the invention is that it can be carried out very easily and continuously.

In a continuous process, the isocyanate prepolymer and then separately the chain extender and dispersant are heated at a rate above the melting point and below the decomposition point of the isocyanate prepolymer and chain extender at such a rate that the incyanato polyaddition reaction is not completed in the mixing zone. is continuously introduced into the mixing zone at a temperature of .

The polyurethane gel obtained in a still flowable and deformable state with a high content of water or alcohol is continuously removed from the mixing zone and, if necessary, this gel is transferred to a short reaction tube fitted with a molding spout. The polyurethane gel thus produced is passed through a fully formed seamless strand,
Obtained as a band or sheet.

This gel can then be used as a bandage on its own, but
The gel can be applied to a woven or non-woven support by applying a tightly mixed mass of gel in conventional coating equipment, for example by knife smearing or by brushing or casting, continuously or intermittently. Preferably, it is combined with a support material.

Although the bandage thus obtained can be sold uncovered, it is preferred that the bandage be sealed in a water-resistant foil that can be opened as required.

This packaging method can also be performed on conventional commercial automatic heat sealing machines.

Finished bandages are used for a variety of purposes in the medical and cosmetic fields, for example, they can be used as bandages for the treatment of inflammatory swellings, as leg compresses for cooling infants, and in particular for performing surgeries on local cooling patients. Used as a compress and facial mask and ice pack for local or general hypothermia.

Example 1 (a) Prepolymer preparation Nitrilene diisocyanate (80% 2,4-isomer and 2
, 6-isomer (20%) were heated to 80° C. in a reaction vessel.

1200 parts by weight of a polyether having a hydroxyl number of 28 obtained by chemically adding 60% by weight of ethylene oxide and 40% by weight of propylene oxide to glycerol was added dropwise to this with stirring over a period of 3 hours.

The reaction mixture was then heated at 80° C. for an additional hour and cooled to room temperature with stirring.

The resulting prepolymer had an incyanate content of 4.2 parts by weight and a viscosity of 5200 centipoise at 25°C.

(b) Manufacture of the bandage: 7 parts by weight of the prepolymer described in (a) were added to 59 parts by weight of water over a period of 3 seconds with mechanical stirring (stirring speed 1165 revolutions/min).

The reaction mixture was stirred for 50 seconds before pouring the mixture into molds.

The internal dimensions of this mold were 25X8X0.5CrrL.

Width 8CrfL cotton fabric (cotton muslin bandage, 34g/4r
? ) is placed longitudinally on a substrate of dimensions 25 x 8 crrL such that 10 crrL of the bandage overlaps the substrate at both ends.

60 seconds after the start of mixing, the reaction started with some foaming (cream time).

Gel time is 90 seconds.

The foaming reaction was completed after 10 minutes. The molded product was removed from the mold after 5 minutes and then sealed in an aluminum boiler coated with polyethylene on the side facing the bandage.

The density of this gel product was 660 kg/m3.

The sealed bandage was stored at -20°C for 24 hours.

The water in the bandage was then allowed to melt and return to room temperature.

Even when this method was repeated in bankruptcy, the usage characteristics of this bandage did not change.

Example 2 The operating procedure is exactly the same as shown in Example 1(b), but
A polyamide-based fabric with a mesh of 1 mr/L and a weight of 130977 d was used instead of the cotton fabric.

Example 3 The operating procedure is exactly the same as shown in Example 1(b), but
A polyamide-based fabric (130,9/w?) was used instead of the cotton fabric, and the dimensions of the base material for the father mold (25X8crrL)
A polyethylene foil matching the above was placed over the reaction mixture at the beginning of the reaction so that the mixture was completely covered with the foil.

Example 4 The operating procedure is exactly the same as shown in Example 1(b), but
Color index No. 4208 instead of 59 parts by weight of water
0.2 parts by weight of No. 5 dye, fragrance oil (inbornyl acetate 6
An emulsion of 3.5 parts by weight of a mixture of 0% by weight and 40% by weight of a condensation product of 1 mol of nonylphenol and 10 mol of ethylene oxide and 55.3 parts by weight of water was used.

Example 5 The operating procedure is exactly the same as shown in Example 1(b), but
50 parts by weight of water, 56 parts by weight of water and 3 parts of ointment for cuts and burns.
Parts by weight were replaced with emulsions.

The composition of the ointment is as follows: liquid phenol (Ph
1 g
, basic bismuth gallate (Bismutum sab
gal icum) 5g1 single lead plaster (Empl
astrum l ithargyri) 20g, ointment base 100g or less.

Example 6 The operating procedure is exactly the same as shown in Example 1(b), but
A suspension of 55 parts by weight of water and 4 parts by weight of powdered titanium dioxide was used instead of 59 parts by weight of water.

Example 7 The operating procedure is exactly the same as shown in Example 1(b), but
Add 46 parts by weight of water instead of 59 parts by weight.
A mixture with 13 parts by weight of all was used.

Example 8 The operating procedure is exactly the same as shown in Example 1(b), but
The reaction mixture used was a mixture of 9.5 parts by weight of the prepolymer described in Example 1(a) 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. there were.

The density of this gel mass is 630 kg/? It was 7Z2.

Example 9 The operating procedure was exactly as shown in Example 1 (b), but the reaction mixture used was 9.5 parts by weight of the prepolymer described in Example 1(a), 52 parts by weight of water and 1.5 parts by weight of methanol. 5 parts by weight and 53.5 parts by weight.

The stirring time was 45 seconds, the cream time was 60 seconds and the gel time was 70 seconds, measured from the beginning of the process of mixing the two reactants.

The density of this gel was 630 kg/7f.

Claims (1)

Claims: 1. A dressing material comprising (a) a layer of polyurethaneurea gel containing water and/or alcohol, and optionally (b) optionally comprising a support layer, an intermediate layer and/or a covering layer.