DE102006040533A1 - Producing foamed adhesives useful in wound or skin care products comprises foaming a mixture of an elastomer and e.g. polyacrylic acid, a polyol and polyvinylpyrrolidone - Google Patents

Abstract

Producing foamed adhesives comprises foaming a mixture of an elastomer, polyacrylic acid, a polyol, polyvinylpyrrolidone and optionally tris(hydroxymethyl)aminomethane or foaming a mixture of an elastomer, a polyacrylate, a polyol, an isocyanate and optionally tris(hydroxymethyl)aminomethane. The elastomer is polyisobutylene, polyisoprene, a styrene-isoprene-styrene, styrene-ethylene-butadiene-styrene or styrene-butadiene-styrene block copolymer or styrene-butadiene rubber. An independent claim is also included for foamed adhesives with a stabilized foam structure produced as above.

Description

The Invention comprises a process for producing foamed adhesives, wherein the foam structure by targeted crosslinking of polyacrylic acids with Nitrogen bases, e.g. Polyvinylpyrrolidones, or polyvalent ones Alcohols, e.g. Ethylene glycol, or by thermally crosslinked Polyacrylates with isocyanates takes place.

adhesive Plasters and their adhesives are known. In the past were usually plaster entire area coated with a zinc-rubber adhesive. The bonding of such Products on the skin shows clear skin irritations after peeling and a mechanical stress on the skin. The bonding can be without aids only in pain solve. Case by case it comes to allergic reactions. The adhesives used lead beyond often to a mass transfer, i. a rewind, on the skin.

The Use of skin-friendly adhesives, such as acrylate adhesives or hydrogels, is due to low shear stability and tack not always optimal. An improvement by a post-treatment, especially networking, is possible however, the overall result is unsatisfactory. The proprioreceptive Effect of these masses is opposite the systems with a resin-rubber adhesive also lower.

Other known adhesive systems based on conventional block copolymers on the one hand by high stabilizer addition not skin-friendly, respectively show by the high cohesiveness so far only aptitude for technical applications. On the other hand, they are not strongly skin-sticky and skin-adhering.

The adhesives mentioned above are pressure-sensitive self-adhesives, being the masses for the Processing in a carrier matrix may be present. As carrier matrix become common organic or inorganic solvents or dispersing understood.

systems without carrier matrix are referred to as 100% systems and are also not unknown. They are processed in the elastic or thermoplastic state. A common one Processing is the melt.

Also such pressure-sensitive hotmelt adhesives are already known in the art described above. They are based on natural or synthetic Rubbers and / or other synthetic polymers.

Polyacrylic acid as an adhesive must be crosslinked to form a gel with a defined structure. The nature of the crosslinker contributes significantly to the structure of the resulting gel. The usual crosslinking agents may be metal ions (eg Al ³⁺ ions) or organic compounds. The crosslinking with aluminum salts proceeds via the coordination of the oxygen functions of the polyacrylic acid to the Al ³⁺ ions. It forms a very dense gel with high viscosity, wherein the viscosity of the gel can be controlled only by the amount of crosslinker (Handbook of Pressure Sensitive Adhesive Technology, page 458 ff, 1999).

In JP 11-228340 are disclosed polyacrylic acid-based gels that use Al ⁺³ compounds as crosslinkers. The use of the absolutely necessary aluminum compound as a crosslinking agent is limited, since otherwise the physical properties of the gel are impaired. If the proportion of aluminum crosslinker is too high, the gel becomes too hard.

From the literature, further examples of crosslinking with multivalent metal ions are known, eg US 3900610 (Zinc salts), US 3770780 or US 3790533 (Titanium compounds). The ionic crosslinking with metal ions leads to hard, viscous and slightly tacky polymer gels (Handbook of Pressure Sensitive Adhesive Technology, page 458 ff, 1999).

One Another problem with the crosslinking of polyacrylic acid to a Self-adhesive gel is a once-made gel with defined physical properties, viscosity, tack etc. in a later manufacturing process are the same must have defined properties. This reproducibility is consuming with the currently known networking technologies or not at all.

In EP 303445 discloses a monolayer gel matrix patch based on water-soluble polymers. Mandatory ingredients include clebopride or a pharmaceutically acceptable salt thereof as the active ingredient, water, water-absorbing agents, and water-soluble polymers. As water-soluble polymers, the person skilled in the art can select from a number of known polymers, such as polyvinyl alcohol, gelatin, polyacrylic acid, sodium polyacrylates, methylcellulose, carboxymethylcellulose, polyvinylpyrrolidone, gum and other crosslinkable polymers, and mixtures thereof.

As a problem is also in EP 303445 the viscosity reduction and adhesive force loss of the polymers by changing the composition, in particular the Vernetzungsagenz shown.

Foamed PSAs are also known. The EP 717091 describes pressure-sensitive adhesive foams and a process for its preparation.

The foaming of polymers is also in the DE 19850340 described. Herein only thermoplastics such as polycarbonate are described as polymers.

In the US 5780523 describes pressure-sensitive self-adhesive compositions and foams. In the US 5780523 In particular, a matrix comprising acrylate and isocyanate is described. The foaming described therein, however, takes place via "expandable particulate materials", ie small spheres filled with liquids which are burst by heating, and which discloses only a reaction between isocyanate and active hydrogens of polyethers and polyacrylates. however, no information is given about the stabilization of the foam, in particular against "cold flow".

The Problem with foamed Adhesive compositions, in particular hydrocolloid foams, is that the Masses a so-called "cold River "have. This leads to make the foam structure unstable and overflow of hours dissolves again.

As "cold River "becomes the Property of uncrosslinked polymers that are made up a predetermined shape by the action of force (e.g., gravity) to deform into another. For example, a sharp cutting edge of such an adhesive in the course of hours to weeks, depending on Molar mass of the polymer, to a more or less rounded edge run. In general leads this to destruction the foam structure towards a smooth material coating. Avoided so far if you run too strong by the addition of e.g. fillers, but the masses are harder do. Another problem arises because a complete inhibition the cold flow leads to a loss of adhesion.

Desirable would it be Accordingly, a method to provide, which allows a stabilized and in particular stabilized against the "cold river" and foamed To produce adhesive. It should be advantageous but also a certain amount of cold River "individual be adjustable in order to set a sufficient adhesive force without while compelling on the otherwise necessary addition of resins and back to other tacklers to grab.

The to be solved Problem exists u.a. In doing so, the ratio of networking to "cold River "so to vary that the foam structure obtained under normal mechanical stress remains, i. remains stable.

• 1.) Polyacrylsäure
• 2.) mehrwertiger Alkohol, insbesondere Ethylenglycol und/oder Polyethylenglycol,
• 3.) gegebenfalls Tris-(hydroxymethyl)aminomethan (IRIS)
• 4.) Poly(1-viny-2-pyrrolidinone) (PVP)

The process according to the invention for producing and / or stabilizing foamed adhesives comprises the steps of providing one or more adhesive polymers selected from the group of polyisobutylene (PIB), polyisoprene, styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butadiene-styrene Block copolymer (SEES), styrene-butadiene-rubber (SBR), styrene-butadiene-styrene block copolymer (SBS) or mixtures thereof,
and subsequent addition of the further components according to the invention in the order listed, it being recommended after each addition to homogenize the mass,

• 1.) polyacrylic acid
• 2.) polyhydric alcohol, in particular ethylene glycol and / or polyethylene glycol,
• 3.) optionally tris (hydroxymethyl) aminomethane (IRIS)
• 4.) Poly (1-vinyl-2-pyrrolidinones) (PVP)

• 1.) Polyacrylat
• 2.) gegebenenfalls mehrwertiger Alkohol, insbesondere Ethylenglycol und/oder Polyethylenglycol, Fettsäureester oder Öle,
• 3.) gegebenfalls Tris-(hydroxymethyl)aminomethan (IRIS)
• 4.) Isocyanat

When polyacrylates and isocyanate are used, the polyacrylate is added in place of the polyacrylic acid. Isocyanate is then added as the crosslinking step instead of the PVP. The addition of isocyanate then takes place as a last component:

• 1.) polyacrylate
• 2.) optionally polyhydric alcohol, in particular ethylene glycol and / or polyethylene glycol, fatty acid esters or oils,
• 3.) optionally tris (hydroxymethyl) aminomethane (IRIS)
• 4.) isocyanate

The polyhydric alcohols can when using polyacrylate / isocyanate by fatty acid esters or other oils be replaced because the crosslinking function by the isocyanate / polyacrylate System adopted becomes. But the polyhydric alcohols, fatty acid esters or oils can are preferably added, since they serve advantageously as a plasticizer can.

The Adhesive polymer or scaffold polymer, such as polyisobutylene (PIB), polyisoprene, styrene-isoprene-styrene block copolymer (SIS), Styrene-ethylene-butadiene-styrene block copolymer (SEES), styrene-butadiene rubber (SBR), styrene-butadiene-styrene block copolymer (SBS) or mixtures thereof, is submitted and homogenized. The backbone polymers form the matrix for the Recording the components to be stabilized.

The Adhesives can solvent-based be, in which case it is advantageous to work in a mixer. The But adhesive can also be solvent-free be, so-called hotmelt mass, so then preferably in the kneader or Extruder is processed.

The Framework polymers / Klebmassenpolymere, are preferably in an amount of about at least 15% by weight, preferably at least 20 wt.%, In particular at least 30 wt.%, Based on the total mass of the adhesive matrix.

Maximum they are in a proportion of preferably 65 wt.%, Preferably maximum 55% by weight, more preferably up to 45% by weight, always upholstered on the total mass of the adhesive.

In front the addition of the invention the polyacrylic acid or polyacrylate, it is advantageous for the composition to have resin components, e.g. Hydrocarbon resins such as Regalite 7100 or hydrogenated rosin glycerol esters like Staybilite ester 10, advantageously at levels of 1 to 40 wt%, preferably 2 to 30 wt.%, Particularly preferably 5 to 30 wt.% Added together become.

Subsequently, will for example, the polyacrylic acid added. This should, as mentioned initially homogenized as they come in contact with the cross-linking reagent if necessary could react to hard, flaky particles.

The Addition of the polyacrylic acid or polyacrylate is preferably in a proportion of about at least 1% by weight, preferably at least about 3% by weight, especially preferably at least 5% by weight. Maximum proportion of polyacrylic acid / polyacrylate is preferred a proportion of about 30% by weight, preferably at most 20% by weight, especially preferably not more than 20 wt., In each case based on the total mass of Adhesive.

Subsequently, will homogenized and only after step 1. can be optional other components such as fillers and / or hydrocolloid particles, e.g. Cellulose (Elcema P050), or Carboxymethylcellulose (Cekol 30000P) can be added.

In the further steps (2-4.) Then the crosslinker components, the polyhydric alcohols, for example ethylene glycol, and, if so preferably, IRIS, and PVP added and homogenized.

The crosslinking and stabilizing components, the polyvalent ones Alcohols, such as, advantageously, ethylene glycol or polyethylene glycol, e.g. Lutrol 400, are used in a proportion of about at least 3 wt.%, preferably to a proportion of at least 5 wt.% And at most to a proportion of 30% by weight, particularly preferably at most 15% by weight, in each case based on the total mass of the adhesive added.

The Addition of IRIS is optional and causes an additional Networking and thus "Verstrammung" the matrix.

When last step according to the invention (4) the addition of PVP, e.g. Kollidon 30.,

The Mixture is then finally homogenized and can be squeezed out.

If instead of PVP / alcohol / TRIS stabilization, however, isocyanate as a chemical crosslinker and Stabilizer is used (in polyacrylates, step 4), so first after homogenization of the base polymer, the polyacrylate must be added (step 1.) and finally the isocyanate (step 4.). Here, too, fillers, such as, for example, carboxymethylcellulose, may preferably be added to the mixture after the first step. The isocyanate is added as the last component and preferably homogenized at temperatures of less than 80 ° C. for a maximum of 30 minutes, since thermal crosslinking at higher temperatures could otherwise begin immediately. The further processing takes place advantageously within 24 hours, since the networking continues independently.

To conclude following steps 1.-4. stabilized Foamed foams, as is known in the art

If chemically with e.g. Azodicarbonamid is foamed, so this is after the crosslinker, ie after step 3.) or 4.) in the PVP / alcohol / TRIS stabilization or after step 4.) in the isocyanate stabilization added. The foaming is then carried out by heating to about 240 ° C at the extruded adhesive.

In the foaming with carbon dioxide (CO ₂ ), the mass is prepared in an extruder and either foamed in-line, or entered into a separate extruder for foaming. In any case, the compounding of the mass should already be completed at this time. The CO ₂ is injected as a supercritical fluid into the extruder and dissolved in the mass. By discharging the mass from the nozzle, the supercritical fluid is expanded and thus again gaseous. The resulting gas bubbles generate the foam.

To discharging from the nozzle can form, cover and punch the adhesive sheet, for example be made into patches.

According to the invention is in The method described a compromise between the stability and the Adhesive strength of the foamed Adhesive over the setting of the cold river brought about.

simplified expressed is through a network that slows down the cold river but the Flexibility of Mass does not cancel, a stabilization of the foamed adhesives reached. A stabilization of the foam structure and its properties is achieved according to the invention.

According to the invention relationship from networking to "cold River "so varied, that the foam structure obtained under normal mechanical stress remains, i. remains stable. A stabilized foam structure is according to the invention exactly then given.

When Adhesives are preferably polyisobutylenes use.

The So stabilized masses are hereafter due to their shares on hydrocolloids, e.g. Cellulose (Elcema P050), or carboxymethylcellulose (Cekol 30000P), or polyvinylpyrrolidone (Kollidon 30), in total also called hydrocolloids. These hydrocolloid masses are preferred because they are capable of wound fluids in the foamed structure to absorb to a greater extent wherein the hydrocolloid particles promote absorption by swelling.

The Problem with hydrocolloid foams was that the masses have a cold flow. This leads to, that the foam structure is not stable and can change over the course of hours dissolve again. The inventive method allows the production of foam-stabilized adhesives. The combination and process sequence of the components contained lead to a network and form over it In addition, a stabilizing network within the adhesives on. The cold flow is severely restricted to what is completely suppressed again results in stable foam structures.

The crosslinker components according to the invention are added to the adhesive after the addition of the scaffold-forming polymers and if appropriate the tackifier resins and, if present, the fillers (step 2 to 4). The components are advantageously added one at a time. This is advantageous to ensure homogenization of the components. In the case of polyacrylic acid / polyvinylpyrrolidone / alcohol or polyacrylic acid / polyvinylpyrrolidone / alcohol / tris (hydroxymethyl) aminomethane stabilization, the polyacrylic acid is first homogenized in the mixture, and then the alcohol and tris (hydroxymethyl) -aminomethan or the Alcohol in the absence of tris (hydroxymethyl) aminomethane added and homogenized. The polyvinylpyrrolidone is added as the last of the crosslinker components. With his help binds the still free acid groups or alcohols.

in the In case of stabilization with polyacrylates and isocyanate must the isocyanate be added as the last component, otherwise in the heat would immediately use the crosslinking reaction. This would be about the covalent crosslinking make further processing of the mass impossible.

All these components of the invention, their combination and mode of use are responsible for the stabilization of the finally produced foam.

When Stabilization according to the invention is in particular the reduction the cold flow of the foamed Adhesive called. The purpose is the structure of the foam to conserve.

So According to the invention, the formation a stabilized foam structure by a on electrostatic Attraction based network.

This Network is formed from the nitrogen (N) function of polyvinylpyrrolidone with the OH functions of the polyacrylic acid and of the polyethylene glycol, or the OH functions of the polyethylene glycol or tris (hydroxymethyl) aminomethane with the COOH function of the adhesive polymers. The crosslinking components PVP and IRIS stabilize the foam and contribute to both to increase the degree of crosslinking of the adhesive.

The process according to the invention is accordingly a production process for foamed adhesives and at the same time a process for stabilizing the foams produced:
A stabilization of the foam structures can be observed with the method according to the invention over a period of more than 1 year.

Next Ethylene glycol or polyethylene glycol may according to the invention also other polyhydric alcohols are used, e.g. polypropylene glycol or triethylene glycol.

It can preferably the components acrylic acid, e.g. Carbopol, with ethylene glycol / polyvinylpyrrolidone, e.g. Kollidon 90, or acrylic acid, e.g. Carbopol, with ethylene glycol / PVP / TRIS as crosslinking according to the invention Components are used. These recipes are the networks linked reversibly, because all components are water-soluble are. In contrast, it comes in the stabilization of the foams Polyacrylate and isocyanate to an irreversible, covalent linkage of Components polyacrylate and isocyanate. This crosslinking reaction is thermally triggered. In addition to the thermal variant is erfindunsgegmäß also a UV crosslinking of Polyacrylates possible.

The Production of the compositions according to the invention, preferably hydrocolloid compositions based on polyisobutylene, takes place advantageous in a twin-screw extruder.

The Method is then a continuous production in an extrusion process, by compounding and concluding foamed becomes.

The individual components are sequentially, as previously stated, added and mixed or homogenized.

For foaming, supercritical CO _{2 is} preferably metered in and mixed in at the rear of the extruder. The gas dissolves in the polymer matrix and is released abruptly after the mass leaves a slot die. This creates an open-cell structure of the mass film.

In addition to CO ₂ can also be foamed with inert gases such as nitrogen, noble gases, hydrocarbons or air or mixtures thereof. In some cases, foaming by thermal decomposition of gas evolving substances such as azo, carbonate and hydrazide compounds has been found to be suitable.

The degree of foaming, ie the gas fraction, should preferably be at least about 5% by volume and may advantageously be up to about 85% by volume, in each case based on the total volume of the foamed adhesive. In practice, values of 10% by volume to 75% by volume, preferably 50% by volume, have proven to be well, which represent advantageous ranges according to the invention. If you work at relatively high temperatures of about 140 ° C and relatively high internal pressure, resulting in very open-pored adhesive foam layers be especially good air and water vapor permeable.

Open-cell or open-pored foams are therefore preferred.

Possible are so both closed-cell foams as well as open-celled foams produced. The open-celled foams are preferred since these a combination of moist wound healing and spontaneous absorption of liquids, like wound secretions, sweat or Water, when used in wound or skin care.

Instead of the production and stabilization in a continuous extrusion process Alternatively, it may also be a discontinuous preparation in one Kneading process done by compounding and finally foamed

The Preparation of wound or skin care products is by the method of the invention possible. The inventively produced foamed Adhesives can thereby preferably used for the production of patches.

The thus prepared inventive plaster can preferably "out one piece ". This means, it will be first a foamed Web produced by extrusion. This adhesive sheet is then to pave with the aid of a suitable tool (e.g., calender) formed. When molding the part of the foam is again rolled out to a track that is not in the area of the wound pad lies. The advantage of this method is that you are in one Step the entire plaster can form and then only still punch out the pavement from the train. In addition to the processing offers the advantage that only one adhesive in the whole product for Use comes. This not only simplifies the design, but also also reduced the number of feedstocks, resulting in a reduction a potential allergenic risk.

The foamed adhesive film is then formed using a calender (see 1 ). In the calender, the desired shapes of the Wundpads are milled. He serves as a template. In this case, the part of the web that does not serve as a wound dressing is rolled out again to a foam-free track. Preferably, the desired carrier material is already applied to the adhesive web during molding. One then obtains an adhesive web which has a flat adhesive layer in the edge region and several wound pads. The web is then covered with a release liner. In a further step, individual plasters can then be punched out and packed from this web. With the help of this method, different pavement sizes and shapes are possible because the shape and size is limited only by web width and the cutout in the calender.

Examples

The following tables list exemplary formulations of the adhesives of the invention and their commercial designations: Description of the Components: Oppanol B80: Polyisobutylene MW1.000.000 Oppanol B12SFN: Polyisobutylene MW50,000 Oppanol B10SFN: Polyisobutylene MW30,000 Regalite 7100: Hydrocarbon resin, KW resin Carbopol ^® 980NF: polyacrylic acid Kollidon ^® 90: Polyvinylpyrrolidone MW1.000.000-1.500.000 Kollidon ^® 30: Polyvinylpyrrolidone MW44,000-54,000 Cekol ^® 30000P: carboxymethylcellulose AHT22.0.0: polyacrylate Cetiol V: oleate Lutrol 400: Polyethylene glycol (PEG-8) trometamol: Tris (hydroxymethyl) aminomethane

Example 1:

In a kneader, 30.84 g (16.00% w / w) granulated Oppanol B80 are submitted and at a Vor running temperature of 100 ° C kneaded for 5 min. Successively add 51.30 g (27.00% w / w) of Oppanol B10SFN, 38.00 g (20.00% w / w) of Regalite 7100 and 28.50 g (15.00% w / w) of Carbopol 980NF (step 1) too. After each addition, homogenize for about 5 minutes. After the last addition, homogenize for a period of 120 minutes. After the homogenization phase, 19.00 g (10.00% w / w) of Lutrol 400 (step 2) and 3.80 g (2.00% w / w) of trometamol (IRIS) (step 3) are added and homogenized for a further 90 min. In a final step, 19.00 g (10.00% w / w) of Kollidon 30 are added. This is followed by a homogenization phase of 60 minutes.

ever After further action are used for the production of closed-cell foams 3.80 g azodicarbonamide added and homogenized for 30 min. The sample are then squeezed and thermally foamed.

To produce open-celled foams, the mass is gassed in an extruder with supercritical CO ₂ and then formed into the web, which leads to foaming.

Example 2:

In a kneader is 30.84g (16.00% w / w) granulated Oppanol B80 submitted and kneaded at a flow temperature of 100 ° C for 5 min. Subsequently Successively add 51.30 g (27.00% w / w) of Oppanol B10SFN, 38.00 g (20.00% w / w) Regalite 7100 and 28.50g (15.00% w / w) Carbopol 980NF to. After each addition, homogenize for about 5 minutes. After the last one Addition is for homogenized for a period of 120 minutes. After the homogenization phase One adds 19.00g (10.00% w / w) Lutrol 400 and 3.80g (2.00% w / w) trometamol (IRIS) and homogenized for another 90 min. In a last step 19.00g (10.00% w / w) Kollidon 30 is added. It closes a homogenization phase of 60min.

ever After further action are used for the production of closed-cell foams 3.80 g azodicarbonamide added and homogenized for 30 min. The sample are then squeezed and thermally foamed.

To produce open-celled foams, the mass is gassed in an extruder with supercritical CO ₂ and then formed into the web, which leads to foaming.

Example 3:

In a kneader is 26.60g (13.89% w / w) granulated Oppanol B80 submitted and kneaded at a flow temperature of 100 ° C for 5 min. Subsequently one successively gives 43,70g (22,82% w / w) of Oppanol B12SFN and 5,70g (2.98% w / w) Regalite 7100 too. After each addition, homogenize for about 5 minutes. After the last addition is for homogenized for a period of 60 minutes. After the homogenization phase Add 9.50g (4.96% w / w) of Cekol 30000P and homogenize further 60min. In another step, 95.00g (49.60% w / w) AHT22.0.0 added. It closes Homogenization phase of 30min, while at room temperature chilled becomes. In a final step, 9.50g (4.96% w / w) of Cetiol V and 1.52 g (0.79% w / w) of isocyanate and homogenized for 30 minutes.

ever After further action are used for the production of closed-cell foams 3.80 g azodicarbonamide added and homogenized for 30 min. The sample are then squeezed and thermally foamed.

To produce open-celled foams, the mass is gassed in an extruder with supercritical CO ₂ and then formed into the web, which leads to foaming.

The according to the invention prepared adhesive can be over the entire surface on a suitable cuddly carrier material, such as woven, knitted fabric, Sheets, fleece, paper, foam or laminates thereof applied be advantageous, it can also limited in area, for example by screen printing, thermal screen printing, thermoflex printing or gravure printing be applied. this leads to to a particularly good air and water vapor permeability the adhesive layer.

ever after carrier material and its temperature sensitivity can be the self-adhesive layer applied directly or first applied to a submount and then on the final one carrier be transferred. Also a subsequent calendering of the coated Product and / or pretreatment of the support, such as corona irradiation, for better anchoring of the adhesive layer may be advantageous.

To the coating usually becomes the carrier material on the adhesive side with an adhesive-repellent carrier material, like siliconized paper, covered. Subsequently, the patches are in the desired Size punched out and optionally individually sealed and sterilized, preferably through gamma rays.

Claims (11)

Process for producing foamed adhesives comprising the steps of providing one or more adhesive polymers chosen from the group of polyisobutylene, polyisoprene, styrene-isoprene-styrene block copolymer, Styrene-ethylene-butadiene-styrene Block copolymer, styrene-butadiene rubber, styrene-butadiene-styrene block copolymer or mixtures thereof, adding 1. polyacrylic acid, Second at least one polyhydric alcohol, in particular ethylene glycol and / or polyethylene glycol, 3. optionally tris (hydroxymethyl) aminomethane and 4. poly (1-vinyl-2-pyrrolidinone), or adding 1. polyacrylates 2. if applicable, at least one polyvalent one Alcohol, in particular ethylene glycol and / or polyethylene glycol, Third optionally tris (hydroxymethyl) aminomethane (IRIS) and 4th isocyanate and final Foaming. Method according to claim 1, characterized that after each addition, a homogenization of the mass takes place. A method according to claim 1 or 2, characterized gekennzeichnte, that in addition before adding the polyacrylic acid or polyacrylate hydrocarbon resins and / or hydrogenated rosin glycerol esters, advantageously to proportions of from 1 to 40% by weight, preferably from 2 to 30% by weight, particularly preferably 5 to 30% by weight, are added. Method according to one of the preceding claims, characterized indicated that in addition after the addition of the polyacrylic acid or polyacrylate other components, in particular fillers and / or hydrocolloid particles are added. Method according to one of the preceding claims in one continuous extrusion process. Method according to one of the preceding claims in one discontinuous kneading process. Method according to one of the preceding claims Production foamed Adhesives with stabilized foam structure. Method according to claim 7, characterized in that that the foam has an open-cell structure. Method according to one of the preceding claims Manufacture of wound or skin care products, in particular patches, characterized in that the foamed adhesive is applied to a carrier material, in particular fabrics, knitted fabrics, films, fleece, paper, foam or laminates thereof, is optionally calendered retrospectively and / or a pretreatment of the carrier, such as corona irradiation, for better anchoring of the adhesive layer takes place. foamed Adhesives with stabilized foam structure based on polyisobutylene (PIB), polyisoprene, styrene-isoprene-styrene block copolymer (SIS), Styrene-ethylene-butadiene-styrene Block copolymer (SEES), styrene-butadiene-rubber (SBR), styrene-butadiene-styrene block copolymer (SBS) or their mixtures available according to one of the methods according to any one of the preceding claims. Use of the adhesives according to claim 10 in wound or skin care products.