DE10257002A1 - Open-cell hydrogel foams based on crosslinked acid-functional polymers, useful for absorbing body fluids in sanitary articles, include skin care agents - Google Patents

Abstract

Open-cell hydrogel foams based on crosslinked acid-functional polymers include skin care agents. An Independent claim is also included for production of the foams by treating a hydrogel foam with a solution or dispersion of the skin care agent and then removing the solvent.

Description

The invention relates to foam hydrogels that Skin care products included.

Foam hydrogels are known. For example, in EP-B-0 858 478 and in WO-A-00/52087 water-absorbent, predominantly open-cell foams based on cross-linked Monomers containing acid groups described. You will be through Foaming a polymerizable aqueous mixture, which too at least 50 mol% neutralized containing acid groups monoethylenically unsaturated monomers, crosslinking agents and at least one Contain surfactant, and then polymerizing the foamed mixture. Foaming the polymerizable Mixture can e.g. B. by dispersing fine bubbles gas inert to radicals or by dissolving one Gases under increased pressure in the polymerizable mixture and Relax the mixture. The water content of the Foams are adjusted to, for example, 1 to 60% by weight. The Foams can optionally post-crosslink be subjected by placing a crosslinker on the foamed Spray material or immerse the foam in it and the Crosslinker loaded foam heated to a higher temperature. The foams are e.g. B. in hygiene articles for acquisition, Distribution and storage of body fluids used.

WO-A-99/44648 are also predominantly open-celled Foams based on cross-linked acid groups Monomers known, with at least 20 mol% of the acid groups containing monomers neutralized with tertiary alkanolamines and / or the free acid groups of the foam hydrogel after polymerizing to at least 20 mol% with at least have been neutralized with an alkanolamine. With Alkanolamine-neutralized foam hydrogels are sticky. The Tackiness can be caused by powdering with finely divided powders such as finely divided silicon dioxide, talc, silicates or starch, be completely eliminated.

WO-A-97/31600 describes an absorber element for use in Hygiene or sanitary articles are known, with several elements a superabsorbent foam in a grid on a carrier are spaced such that the elements in touch the swollen condition around its circumference. One can for example, a monomer foam in the desired grid pattern on the Apply carrier and then polymerize on it or separately manufactured foam elements on the carrier chemically or physically fix in the desired grid pattern.

The present invention is based on the object to provide water-absorbent foam hydrogels, which - for example when used in hygiene articles - one positive influence on the skin of the user of the hygiene article to have.

The object is achieved with foam-like Hydrogels that contain at least one skin care product.

The invention also relates to a method for Production of the foam-like hydrogels, whereby foam-like Hydrogels with a solution or a dispersion of a Treated skin care products and then removed the solvent.

Another object of the invention is the use of foam hydrogels containing at least one skin care product contained, for the absorption of body fluids in Hygiene articles with skin care properties.

• - 10 bis 80 Gew.-% Säuregruppen enthaltende monoethylenisch ungesättigte Monomere, die partiell neutralisiert sind, z. B. zu mindestens 20 Mol-%,
• - gegebenenfalls bis zu 50 Gew.-% andere monoethylenisch ungesättigte Monomere,
• - 0,001 bis 5 Gew.-% Vernetzer,
• - mindestens einen Initiator,
• - 0,1 bis 20 Gew.-% mindestens eines Tensids,
• - gegebenenfalls einen Lösevermittler und
• - gegebenenfalls Verdicker, Schaumstabilisatoren, Polymerisationsregler, Füllstoffe und/oder Zellkeimbildner

enthält. Das Schäumen der polymerisierbaren wäßrigen Mischung erfolgt entweder durch Dispergieren von feinen Blasen eines gegenüber Radikalen inerten Gases oder durch Lösen eines inerten Gases unter einem Druck von 2 bis 400 bar und anschließendes Entspannen der Mischung auf Atmosphärendruck. Die geschäumte Mischung wird dann jeweils unter Bildung eines schaumförmigen Hydrogels polymerisiert. Nach dieser Methode kann man Schaumstofformkörper beliebiger Gestalt herstellen, wobei jedoch Blöcke, aus denen Schaumstoffbahnen oder Platten von beispielsweise 0,5 bis 10 mm Stärke geschnitten werden können, sowie Platten, Bahnen oder Folien bevorzugt sind. Die Oberfläche dieser Formkörper kann dann mit Siliciumdioxid und/oder Tensiden behandelt oder vorzugsweise vor dieser Behandlung einer Nachvernetzung unterworfen werden. Um die Schaumstofformkörper nachzuvernetzen, behandelt man sie zunächst mit einer Lösung eines Vernetzers, z. B. eines mehrwertigen Alkohols wie Propylenglykol oder Butylenglykol, Bisepoxiden oder Polyglycidylverbindungen und erhitzt die mit einer Vernetzerlösung behandelten flächigen Gebilde aus überwiegend offenzelligen, schaumförmigen, vernetzten, Säuregruppen enthaltenden Polymerisaten zur Nachvernetzung der Oberfläche auf Temperaturen von z. B. 120-200°C, wobei die Vernetzer mit den Säuregruppen der schaumförmigen Hydrogele unter Bildung kovalenter Bindungen reagieren. Water-absorbing, predominantly open-cell, foam-shaped, crosslinked polymers containing acid groups are known from the prior art mentioned at the beginning, cf. EP-B-0 858 478, page 2, line 55 to page 10, line 54, WO-A-99/44648, page 4, line 41 to page 27, line 42 and WO-A-00/52087, page 5 , Line 32 to page 28, line 45. They are also referred to as foam-like hydrogels and are obtainable, for example, by first preparing a polymerizable aqueous mixture which

• - 10 to 80 wt .-% monoethylenically unsaturated monomers containing acid groups, which are partially neutralized, for. B. at least 20 mol%,
• optionally up to 50% by weight of other monoethylenically unsaturated monomers,
• 0.001 to 5% by weight of crosslinking agent,
• - at least one initiator,
• 0.1 to 20% by weight of at least one surfactant,
• - where appropriate, a broker and
• - If necessary, thickeners, foam stabilizers, polymerization regulators, fillers and / or cell nucleating agents

contains. The polymerizable aqueous mixture is foamed either by dispersing fine bubbles of a gas which is inert to free radicals or by dissolving an inert gas under a pressure of 2 to 400 bar and then relaxing the mixture to atmospheric pressure. The foamed mixture is then polymerized in each case to form a foam-like hydrogel. This method can be used to produce foam moldings of any shape, but blocks from which foam sheets or sheets of, for example, 0.5 to 10 mm thickness can be cut, and sheets, sheets or foils are preferred. The surface of these moldings can then be treated with silicon dioxide and / or surfactants or preferably subjected to post-crosslinking before this treatment. In order to post-crosslink the foam moldings, they are first treated with a solution of a crosslinking agent, e.g. B. a polyhydric alcohol such as propylene glycol or butylene glycol, bisepoxides or polyglycidyl compounds and heats the sheet-like structures treated with a crosslinking agent solution from predominantly open-cell, foam-like, crosslinked polymers containing acid groups for postcrosslinking of the surface to temperatures of, for. B. 120-200 ° C, wherein the crosslinking agents react with the acid groups of the foam-like hydrogels to form covalent bonds.

Monoethylenically unsaturated containing acid groups Monomers are, for example, acrylic acid, methacrylic acid, Acrylamidopropanesulfonic acid or mixtures thereof are used. The use of acrylic acid as a monomer is particularly preferred Production of water-absorbent polymers. The neutralization of the compounds bearing acid groups is usually carried out with Help aqueous sodium hydroxide solution or potassium hydroxide solution. For neutralization you can also use water glass. To absorb water To produce polymers, one can carry the acid groups Monomers, for example, also in the presence of natural products such as Starch, cellulose, cellulose derivatives or degradation products from Starch such as oxidized starch, enzymatically degraded starch or in the presence of starch digested with acids or bases polymerize. Graft polymers are then formed. Instead of The monomers containing acid groups can also be acrylonitrile or methacrylonitrile optionally in the presence of the above polymerize natural products described and then each time hydrolyze the nitrile groups to acid groups.

The polymerization of the monomers containing acid groups as well acrylonitrile and methacrylonitrile are always present at least one crosslinker, one initiator and one surfactant in an aqueous medium. These substances are in the contain polymerizable aqueous mixture, for example after the so-called whipped foam method (dispersing fine bubbles an inert gas in the polymerizable mixture) or by Solving z. B. carbon dioxide in the polymerizable aqueous Mixing under a pressure of e.g. B. 12 bar and relaxing this Mixture is foamed to atmospheric pressure. The so made flowable foam can then, for example, on a tape that has lateral boundaries, or transferred into shapes and polymerized into tapes, plates, foils or blocks and then be dried. The polymerization is carried out according to the known methods of the prior art performed. she depending on the initiator used Temperature increase, by exposure to light (UV rays), by irradiation with Electron beams or a combination of these measures take place, e.g. B. by increasing the temperature and exposure to UV Rays.

Foam layers with a thickness of up to 1 mm are made for example by one-sided heating or one-sided Irradiate a polymerizable mixture. If flat Foam structures with a thickness of several centimeters to be produced, the polymerizable mixture is heated preferably by exposure to microwaves. Flat structures from foams with a thickness of, for example, 1 mm up to 5 cm, preferably up to 2 cm, is preferably made thereby forth that the polymerization of the polymerizable Foam-shaped mixture initiated on both sides, e.g. B. you can put them on a Heat and tape that has side boundaries Allow UV light to act from above at the same time. During the Polymerization changes the density of the foam only insignificantly. The Water content of the foams has a big impact on the Flexibility of the foams. It is usually 1 to 80% by weight, preferably 5 to 60% by weight.

Foams with particularly high flexibility are obtained when at least 20 mol% of the acid groups of water-absorbing, foam-like, cross-linked, containing acid groups Polymers are neutralized with alkanolamines, cf. WO-A-00/52087, Page 25, line 1 to page 26, line 10. The degree of neutralization the carboxyl groups of the foam hydrogels for example 40 to 95, preferably 55 to 85 mol%. Predominantly open cell means that at least 80% of the foam Hydrogel is open cell. The foam-like hydrogels are preferably 100% open cell.

The water-absorbing, predominantly open-cell, foam-shaped, crosslinked acid groups-containing polymers have, for example, a density of 0.001 to 0.9 g / cm ³ , preferably 0.05 to 0.5 g / cm ³ , a water absorption capacity of at least 5 g / g free absorption rate (FAG) for a 0.9% by weight aqueous saline solution from 4.0 to 100 g / g sec and a vertical wicking time (VWT = time for the expansion of a 0.9% aqueous saline solution in one Foam in the vertical direction) for a height of 4 cm from 0.2 to 120 seconds.

Those described above and known from the prior art flat structures made of foam-like hydrogels if necessary, on one or both sides of a surface post-crosslinking subjected. The post-crosslinking can be carried out both on and also on the moist, foam-like hydrogel after the polymerization be made. To a flat structure from one to produce foam-like hydrogel with a post-crosslinking gradient, the foam is presented as a flat structure. This can for example in the form of individual plates, foils, tapes or other flat geometric shapes of different sizes respectively. For example, you can use a polyacrylate foam as an endless roll, on a conveyor belt only on one side subject a surface post-crosslinking, so that a inhomogeneous post-crosslinking takes place in the z direction, the The x direction and the y direction define the size of the surface.

• - Di- oder Polyglycidylverbindungen wie Phosphonsäurediglycidylether oder Ethylenglykoldiglycidylether, Bischlorhydrinether von Polyalkylenglykolen,
• - Alkoxysilylverbindungen,
• - Polyaziridine, Aziridin-Einheiten enthaltende Verbindungen auf Basis von Polyethern oder substituierten Kohlenwasserstoffen, beispielsweise Bis-N-aziridinomethan,
• - Polyamine oder Polyamidoamine sowie deren Umsetzungsprodukte mit Epichlorhydrin,
• - Polyole wie Ethylenglykol, 1,2-Propandiol, 1,4-Butandiol, Glycerin, Methyltriglykol, Polyethylenglykole mit einem mittleren Molekulargewicht M_w von 200-10000, Di- und Polyglycerin, Pentaerythrit, Trimethylolpropan, Sorbit, die Oxethylate dieser Polyole, z. B. 1 bis 20, vorzugsweise 2 bis 8 Ethylenoxideinheiten pro OH-Gruppe enthaltende Oxethylierungsprodukte von Glycerin, Pentaerythrit und/oder Trimethylolpropan, sowie deren Ester mit Carbonsäuren oder Kohlensäureester wie Ethylencarbonat oder Propylencarbonat,
• - Kohlensäurederivate wie Harnstoff, Thioharnstoff, Guanidin, Dicyandiamid, 2-Oxazolidinon und dessen Derivate, Bisoxazolin, Polyoxazoline, Di- und Polyisocyanate,
• - Di- und Poly-N-methylolverbindungen wie beispielsweise Methylenbis(N-methylol-methacrylamid) oder Melamin-Formaldehyd-Harze,
• - Verbindungen mit zwei oder mehr blockierten Isocyanat-Gruppen wie beispielsweise Trimethylhexamethylendiisocyanat blockiert mit 2,2,3,6-Tetramethyl-piperidinon-4.
• - Lösungen von zwei- oder mehrwertigen Metallsalzen, wobei die Metall-Kationen mit den Säuregruppen des Polymers unter Ausbildung von ionischen oder kovalenten Bindungen bzw. Komplexen reagieren können. Beispiele für zwei- oder mehrwertige Metall-Kationen sind Mg²⁺, Ca²⁺, Al³⁺, Sc³⁺, Ti⁴⁺, Mn²⁺, Fe^2+/3+, Co²⁺, Ni²⁺, Zn²⁺, Zr⁴⁺, La³⁺ und Ce⁴⁺. Bevorzugt verwendete Metall-Kationen sind Mg²⁺, Ca²⁺, Ba²⁺, Al³⁺ und Zr⁴⁺. Die Metall-Kationen können sowohl allein als auch im Gemisch untereinander sowie mit mindestens einem anderen üblichen Vernetzer (vgl. oben) eingesetzt werden. Von den genannten Metall-Kationen sind alle Metallsalze geeignet, die eine ausreichende Löslichkeit in dem zu verwendenden Lösemittel besitzen. Besonders geeignet sind Metallsalze mit schwach komplexierenden Anionen wie Chlorid, Nitrat und Sulfat. Als Lösungsmittel für die Metallsalze können Wasser, Alkohole, Aceton, Dimethylformamid, Dimethylsulfoxid sowie Mischungen dieser Komponenten eingesetzt werden. Besonders bevorzugte Lösemittel sind Wasser und Wasser/Alkohol-Mischungen wie Wasser/Methanol oder Wasser/1,2-Propandiol.

In the case of inhomogeneous postcrosslinking, the crosslinking reagents are applied only to one surface of a foam-like hydrogel, ie compounds which have at least two reactive groups which are capable of under suitable conditions, for. B. when heated to temperatures of at least 70 ° C to react with the acid groups of the foam hydrogel. In this case, it is also possible to control the inhomogeneous crosslinking density in a controlled manner via the penetration depth of the crosslinker. Suitable crosslinkers form covalent or ionic bonds with the carboxyl groups of the polymer matrix. Such compounds are preferably applied in the form of an aqueous solution to the surface of the sheet made of a foam-like hydrogel. The aqueous solution can e.g. B. water-miscible organic solvents, such as alcohols such as methanol, ethanol or i-propanol, acetone, dimethylformamide or dimethyl sulfoxide. In principle, all compounds which can also be used as crosslinkers in the preparation of the hydrogels can be used as crosslinkers. Examples of suitable post-crosslinking agents are:

• Di- or polyglycidyl compounds such as phosphonic acid diglycidyl ether or ethylene glycol diglycidyl ether, bischlorohydrin ether of polyalkylene glycols,
• - alkoxysilyl compounds,
• Polyaziridines, compounds containing aziridine units based on polyethers or substituted hydrocarbons, for example bis-N-aziridinomethane,
• Polyamines or polyamidoamines and their reaction products with epichlorohydrin,
• - Polyols such as ethylene glycol, 1,2-propanediol, 1,4-butanediol, glycerol, methyltriglycol, polyethylene glycols with an average molecular weight M _w of 200-10000, di- and polyglycerol, pentaerythritol, trimethylolpropane, sorbitol, the oxyethylates of these polyols, e.g. , B. 1 to 20, preferably 2 to 8 ethylene oxide units per OH group containing oxyethylation products of glycerol, pentaerythritol and / or trimethylolpropane, and their esters with carboxylic acids or carbonic acid esters such as ethylene carbonate or propylene carbonate,
• Carbonic acid derivatives such as urea, thiourea, guanidine, dicyandiamide, 2-oxazolidinone and its derivatives, bisoxazoline, polyoxazolines, di- and polyisocyanates,
• Di- and poly-N-methylol compounds such as methylenebis (N-methylol-methacrylamide) or melamine-formaldehyde resins,
• - Compounds with two or more blocked isocyanate groups such as trimethylhexamethylene diisocyanate blocked with 2,2,3,6-tetramethyl-piperidinone-4.
• - Solutions of di- or polyvalent metal salts, where the metal cations can react with the acid groups of the polymer to form ionic or covalent bonds or complexes. Examples of divalent or polyvalent metal cations are Mg ²⁺ , Ca ²⁺ , Al ³⁺ , Sc ³⁺ , Ti ⁴⁺ , Mn ²⁺ , Fe ^{2 + / 3 +} , Co ²⁺ , Ni ²⁺ , Zn ²⁺ , Zr ⁴⁺ , La ³⁺ and Ce ⁴⁺ . Preferred metal cations are Mg ²⁺ , Ca ²⁺ , Ba ²⁺ , Al ³⁺ and Zr ⁴⁺ . The metal cations can be used both alone and in a mixture with one another and with at least one other customary crosslinker (cf. above). Of the metal cations mentioned, all metal salts are suitable which have sufficient solubility in the solvent to be used. Metal salts with weakly complexing anions such as chloride, nitrate and sulfate are particularly suitable. Water, alcohols, acetone, dimethylformamide, dimethyl sulfoxide and mixtures of these components can be used as solvents for the metal salts. Particularly preferred solvents are water and water / alcohol mixtures such as water / methanol or water / 1,2-propanediol.

If necessary, acidic catalysts such as for example p-toluenesulfonic acid, phosphonic acid, boric acid or Ammonium dihydrogen phosphate can be added.

Particularly suitable post-crosslinking agents are di- or Polyglycidyl compounds such as ethylene glycol diglycidyl ether, the Reaction products of polyamidoamines with epichlorohydrin, polyvalent Metal cations and 2-oxazolidinone.

In the case of continuous production, the Crosslinker solution preferably by spraying on a solution of the crosslinker for example via nozzles connected in parallel, via which only one Surface of the flat foam-shaped hydrogel is sprayed. The application of the crosslinker solution can be done via any Device known to those skilled in the art. So she can for example compressed air supported or operated without compressed air. Inert carrier gas is preferred for generating the compressed air used, such as nitrogen, argon or helium. Of the surface to be impregnated can also be sprayed be determined and discontinued. The spray angle can have a electronically adjustable nozzle opening can be selected. The Adjustment of the droplet size of the solution to be sprayed can either by adjusting the viscosity of the crosslinker solution and / or via the compressed air. The surface of the two-dimensional structure made of a foam-like hydrogel can be homogeneous or - as already indicated above - inhomogeneous with the crosslinker be provided. The crosslinker or a solution of the crosslinker can for example also in the form of a pattern on the surface of the foam-like hydrogel printed or otherwise in Form of a pattern can be applied. Also one-sided It is possible to apply the crosslinker using a doctor blade.

The postcrosslinker solution is applied, for example, in an amount per surface unit that should not exceed 0.02 ml / cm ² . The surface particularly preferably has an amount of postcrosslinking agent in the range between 0.001 and 0.015 ml / cm ² , most preferably in the range between 0.001 and 0.012 ml / cm ² . This amount of application ensures that the penetration depth of the postcrosslinker solution does not exceed the thickness of the flat structure made of a foam-like hydrogel, so that a postcrosslinking gradient can form.

In general, the post-crosslinker solution is in the concentration it is applied that the solvent does not exceed 50% by weight and the amount of crosslinker not more than 40% by weight, each based on polymer. The surface preferably has a Amount of solvent in the concentration range between 0.1 and 30 % By weight, particularly preferably in the concentration range between 0.5 and 20% by weight, most preferably in the concentration range between 1 and 10% by weight, based in each case on polymer. The Amount of crosslinking agent, based on foam-like polymer for example 0.1 to 25 wt .-%, preferably 0.5 to 10 wt .-% and is usually in the range of 0.5 to 8% by weight.

The post-crosslinking gradient can, for example, thereby be checked that depending on the layer thickness of the submitted flat foam-like hydrogel the depth of penetration of the Crosslinker solution on the application speed and amount of crosslinker controls. In the case of flat structures, you can only use one or also crosslink both surfaces of the foam gel. If flat structures are desired, the one Post-crosslink gradient between the top and bottom are different amounts of crosslinker on the top and the To apply underside. To a flat structure from one foam-like hydrogel with a post-crosslinking gradient It is also possible to manufacture between top and bottom proceed that at least one crosslinker or a solution, which contains at least one crosslinker, on the top and the Underside of the flat structure applied in equal quantities, carries out the post-crosslinking and in this way on both sides Subsequently, surface-crosslinked flat structures once splits, for example in the z-direction of the flat Formed a horizontal cut. If you lead that Cut, for example, in the middle of the z direction on both sides after cross-linked flat structure, it is halved.

After the crosslinker solution has been applied, the crosslinker is added reacted to the foam hydrogel, for example in a downstream drying zone, at one temperature from 80 to 190 ° C, preferably between 100 and 160 ° C. The Reaction time is, for example, 2 minutes to 6 hours, preferably 10 minutes to 2 hours and is usually in the range of 10 Minutes to 1 hour, with both fission products as well Solvent can be removed. The drying and Post-crosslinking can also be done by blowing in a preheated one Carrier gas take place.

Flat structures made of a foam-like hydrogel can directly or after a superficial post-crosslinking on both sides or can preferably be carried out unilaterally, and subsequent treatment with at least one skin care product as Acquisition layer and / or distribution layer and / or Storage layer can be used in hygiene articles. With only one unilateral post-crosslinking of a flat foam-like Hydrogel exists between the top and bottom of the sheet Formed a networking gradient. These are only networked on one side two-dimensional structures made of foam-shaped hydrogels with a Skin care products have been treated are preferred in the Way used in hygiene articles that the surface with the higher network density faces the body. Such one Compared to homogeneously cross-linked flat samples same dimension and same treatment with a skin care product in terms of absorption speed and permeability significantly improved properties.

Suitable skin care products are, for example, panthenol, Collagen, vitamins and protein substances. Zinc oxide and Metal salts of fatty acids such as magnesium, aluminum and / or Zinc stearate or ricinoleate. Vitamins are preferred Vitamin A and Vitamin E. The skin care products are for example in the form of a solution or dispersion on the surface of the applied foam-like hydrogels, e.g. B. by spraying or Dip the foamed materials in a solution of the Skin care products. After impregnating the foam hydrogel becomes that which comes from the active ingredient solutions or dispersions Solvent removed.

• - Glycerin;
• - Alkylenglykole, wie beispielsweise Ethylenglykol, Diethylenglykol, Propylenglykol, Butylenglykol, Hexylenglykol sowie Polyethylenglykole mit einem durchschnittlichen Molekulargewicht von 100 bis 1000 Dalton;
  technische Oligoglyceringemische mit einem Eigenkondensationsgrad von 1,5 bis 10 wie etwa technische Diglyceringemische mit einem Diglyceringehalt von 40 bis 50 Gew.-%;
• - Metylolverbindungen, wie insbesondere Trimethylolethan, Trimetylolpropan, Trimetylolbutan, Pentaerythrit und Dipentaerythrit;
• - Niedrigalkylglucoside, insbesondere solche mit 1 bis 8 Kohlenstoffen im Alkylrest, wie beispielsweise Methyl- und Butylglucosid;
• - Zuckeralkohole mit 5 bis 12 Kohlenstoffatomen, wie beispielsweise Sorbit oder Mannit;
• - Zucker mit 5 bis 12 Kohlenstoffatomen, wie beispielsweise Glucose oder Saccharose;
• - Aminozucker, wie beispielsweise Glucamin.

In order to improve the flow behavior, hydrotropes, such as, for example, ethanol, isopropyl alcohol or polyols, can also be added to the solution or the dispersion which contains at least one skin care agent. Polyols that come into consideration here preferably have 2 to 15 carbon atoms and at least two hydroxyl groups. Typical examples are

• - glycerin;
• - Alkylene glycols, such as ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, hexylene glycol and polyethylene glycols with an average molecular weight of 100 to 1000 Daltons;
  technical oligoglycerol mixtures with a degree of self-condensation of 1.5 to 10 such as technical diglycerol mixtures with a diglycerol content of 40 to 50% by weight;
• - Methyl compounds, such as especially trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol and dipentaerythritol;
• - Lower alkyl glucosides, especially those with 1 to 8 carbons in the alkyl radical, such as methyl and butyl glucoside;
• - Sugar alcohols with 5 to 12 carbon atoms, such as sorbitol or mannitol;
• - Sugar with 5 to 12 carbon atoms, such as glucose or sucrose;
• Aminosugars such as glucamine.

Perfume oils and plants also come as skin care products isolated drugs into consideration, e.g. B. Mixtures of natural and synthetic fragrances. Natural fragrances are Extracts of flowers (lily, lavender, roses, jasmine, neroli, ylang- Ylang), stems and leaves (geranium, patchouli, petitgrain), Fruit (anise, coriander, caraway, juniper), fruit peel (Bergamot, lemon, oranges), roots (mace, angelica, Celery, cardamom, costus, iris, calmus), wood (pine, sandal, Guaiac, cedar, rosewood), herbs and grasses (tarragon, Lemongrass, sage, thyme), needles and twigs (spruce, fir, Pine, mountain pine), resins and balms (galbanum, elemi, benzoin, Myrrh, olibanum, opoponax). Animal raw materials also come such as civet and castoreum. typical synthetic fragrance compounds are products of the type Esters, ethers, aldehydes, ketones, alcohols and hydrocarbons. Fragrance compounds of the ester type are e.g. B. benzyl acetate, Phenoxyethyl isobutyrate, p-tert-butylcyclohexyl acetate, Linalyl acetate, dimethylbenzylcarbinylacetate, phenylethyl acetate, Linalyl benzoate, benzyl formate, ethyl methylphenylglycinate, Allyl cyclohexyl propionate, styrallyl propionate and benzyl salicylate. To the For example, ethers include benzyl ethyl ether, among the aldehydes z. B. the linear alkanals with 8 to 18 carbon atoms, Citral, Citronellal, Citronellyloxyacetaldehyde, Cyclamenaldehyde, Hydroxycitronellal, Lilial and Bourgeonat, to the ketones z. B. the Jonone, cc-isomethyl ions and methylcedryl ketone, to the Alcohols Anethof, Citronellol, Eugenol, Isoeugenol, Geraniol, Linalool, phenylethyl alcohol and terioneol, among the Hydrocarbons mainly include the terpenes and balms. Prefers however, mixtures of different fragrances are used create an appealing fragrance together. Also ethereal Oils of lower volatility, mostly as aroma components used are suitable as perfume oils, e.g. B. sage oil, Chamomile oil, clove oil, lemon balm oil, mint oil, cinnamon leaf oil, Linden blossom oil, juniper berry oil, vetiver oil, oliban oil, galbanum oil, Labolanum oil and Lavandin oil. Bergamot oil, Dihydromyrcenol, lilial, lyral, citronellol, phenylethyl alcohol, a- Hexylcinnamaldehyde, geraniol, benzylacetone, cyclamenaldehyde, Linalool, Boisambrene Forte, Ambroxan, Indol, Hedione, Sandelice, Lemon oil, mandarin oil, orange oil, allylamyl glycolate, Cyclover Valley, Lavender Oil, Muscat Sage Oil, β-Damascone, Geranium oil bourbon, cyclohexyl salicylate, Vertofix Coeur, Iso-E-Super, Fixolide NP, Evernyl, Iraldein gamma, phenylacetic acid, Geranyl acetate, benzyl acetate, rose oxide, romillate, irotyl and floramate. The perfume oils are either alone or in mixtures used.

A list of suitable ingredients for skin care products can be obtained from the CTFA (The Cosmetic, Toiletry and Fragrance Association) can be obtained. From this list you can then make more specific or preferred ingredients are selected such. B. allantoin, Aluminum hydroxide gel, calamine, cocoa butter, dimethicone, Cod liver oil, glycerin, kaolin, petrolat, lanolin, mineral oil, Shark liver oil, white petrolatum, talc, topical starch, zinc acetate, Zinc carbonate, zinc oxide, derivatives of living yeast cells, aldioxa, Aluminum acetate, microporous cellulose, cholecalciferol, Colloidal oatmeal, cysteine hydrochloride, dexpanthenol, Peruvian Balsam oil, protein hydrolyzates, racemic methionine, Sodium bicarbonate, vitamin A, buffered mixture of cationic and anionic exchange resins, corn starch, trolamine, bismuth subnitrate, Boric acid, iron chloride, Polyvinylpyrrolidone-vinyl acetate copolymers, sulfur, tannic acid and mixtures thereof. Is the Skin care active ingredient is not soluble, it is in the Composition dispersed with a dispersant. The Dispersant is to be selected from Diethanolamine polyoxyethylene oleyl ether phosphate, polyhydroxy stearic acid, Polyglyceryl-6-polyricinoleate, neopentylglycol diisostearate, Propylene glycol dicaprate, isoeicosan and polyisobutene and quaternium 18, Phenylthiomethylene and quaternium-18 hectorite and triethyl citrate, Isohexadecane and quaternium-18 hectorite and propylene carbonate, mineral oil and quaternium-18 hectorite and propylene carbonate, Isopropyl myristate and stearalkonium hectorite and propylene carbonate, Cyclomethicone and Quaternium 18 and SDA 40, lanolin oil and Isopropyl palmitate and stearalkonium hectorite and propylene carbonate and Propylparaben or 1-eicosanol and mixtures thereof. The Skin care composition preferably contains 40 to 90% care products (Emollient) and 10 to 60% of an immobilizing agent, wherein the care product is selected from the following types: Petroleum-based fatty acid esters, alkyl ethoxylate, fatty acid ester ethoxylates, Fatty alcohol, polysiloxane and mixtures thereof.

The proportion of skin care products in the solutions or dispersions can be 1 to 50, preferably 5 to 40% by weight.

The hygiene articles are, for example Baby diapers, incontinence products, feminine hygiene products, wound dressings or wound dressings. Generally lies in a hygiene article a combination of liquid-impermeable backsheet, liquid-permeable topsheet and absorbent core (absorbent core). Such hygiene articles are known, cf. for example EP-A-0 689 818. The absorbent core is between top sheet and fixed backsheet. Optional elastic cuffs and self-adhesive closures can be integrated into the hygiene article.

A preferred structure of such a hygiene article is known for example from the U.S. Patent 3,860,003.

The top sheet is soft, the skin is not lovely liner. The top sheet is water permeable and allows a quick passage of the to be absorbed Body fluid into the subsequent absorbent core. The topsheet can be made a variety of different materials are made, for example porous foams, perforated synthetic Films, natural fibers (cellulose, cotton fibers), synthetic fibers (Polyester, polypropylene fibers) or a combination of Natural fibers and synthetic fibers. The top sheet is preferably made hydrophobic material made to protect the skin of the user prolonged exposure to aqueous liquids protect.

The topsheet can be made from different materials, such as woven, non-woven, spun or combed fiber mix. Combed fiber mixture is preferably used, which is thermally bound to the top sheet. The weight per unit area of the top sheet is preferably 18 to 25 g / m ² , it has a tensile strength of at least 400 g / cm in the dry state and 55 g / cm in the wet state.

Topsheet and backsheet are arranged in a suitable manner in one the manufacturing method known to those skilled in the art. The absorbent core is positioned between the top sheet and back sheet.

The backsheet is usually liquid-impermeable Materials used, such as polyolefins (e.g. Polyethylene backsheets) to wear the clothing in front of one to protect any leakage.

The open-cell hydrophilic treated with a skin care product Foam from crosslinked monomers containing acid groups used according to the invention within the absorbent core. by virtue of their extraordinary properties, such as fluid intake and forwarding and storage are in particular one Flat structures having post-crosslinking gradients foam hydrogels for use as acquisition and distribution layer or generally completely as absorbent core predestined.

The foams described above can be used as the absorbent core perform various functions in hygiene articles, namely Acquisition, distribution and storage. The absorbent core can also two or more, e.g. B. 3, 4 or 5 to be used flat Structures from the foam-like hydrogels according to the invention contain.

The individual functions can either be completely taken over or are supported by other components, e.g. B. storage is increased by the addition of superabsorbent granules or the acquisition and distribution by others Components such as high loft nonwovens, polypropylene nonwovens, Polyester fleece or chemically modified cellulose optimized become.

Determination of the monomer foam density

Exactly 100 ml of the monomer foam are poured into a measuring cylinder and the weight of this foam volume is determined. The density in g / cm ^{3 is} obtained by dividing the determined weight in g by 100.

Determination of the polymer foam density

The density of superabsorbent foams is determined gravimetrically. From a uniform foam layer with a defined thickness between 3 and 5 mm, for example, you cut with a sharp knife squares with a side length of 5 cm. This Samples are weighed and the weight obtained is calculated from Measured volume divided.

Determination of the absorption capacity

The absorption capacity of the foam-like superabsorbent of water per gram of superabsorbent is determined on pieces of foam which have a thickness of 3 mm and each weigh 1 g. The absorption capacity is checked according to the so-called teabag test. A 0.9% saline solution is used as the liquid. 1 g of the foam-like material is filled into a tea bag, which is then closed. Make sure that the tea bag offers enough space to swell completely. The tea bag is then a certain time, for. B. 30 min, immersed in the liquid and after a draining time of z. B. weighed back 10 minutes. To determine the blank value, a tea bag without foam-like superabsorbent is immersed in the solution and the weight of the tea bag is determined under the conditions described above. The absorption capacity then results from the following equation (1):

G _TS Weight of the tea bag with super absorber foam
G _T Weight of the tea bag in a blind test


in which
G _S Weight of the weighed superabsorbent foam

Determination of the recording speed

The free absorption speed (FAG) is determined by cutting rectangular samples with a weight of 0.5 g (W ₁ ) out of uniformly 3 mm thick foam layers with the aid of a sharp knife. These samples are poured into a Petri dish with 10 g (W ₂ ) (all weights are carefully measured) of 0.9% saline. A stopwatch is used to determine the time it takes for the foam sample to completely absorb the 0.9% saline solution. The absorption rate (FAG) in g / g.sec is calculated from the following equation (2):

FAG = W ₂ / W ₁ .measured time in sec. (2)

Vertical Wicking Time VWT

0.9% is placed in a Petri dish (10 cm in diameter, 1 cm high) Saline solution filled up to a height of 0.5 cm. Then a glass tube (diameter 1 cm, 15 cm high) is just over placed on the bottom of the bowl. A 6 cm long foam strip with square base (5 × 5 mm) is with 2.4 and 6 cm provided a mark and inside the glass tube in the Liquid provided. At the same time the time measurement started. The time in seconds to reach each Marking is necessary, will be determined.

acquisition time

The open-cell polyacrylate foam is cut into 1.5 mm, 2 mm or 4 mm thick layers. A commercially available diaper is carefully cut open, the high-loft serving as the acquisition medium is removed and the open-cell polyacrylate foam layer is inserted instead. The diaper is closed again. Synthetic urine replacement solution is applied through a plastic plate with a ring in the middle (inner diameter of the ring 6.0 cm, height 4.0 cm). The plate is loaded with additional weights so that the total load on the diaper is 13.6 g / cm ² . The plastic plate is placed on the diaper so that the center of the diaper is also the center of the feed ring. 60 ml of 0.9% by weight sodium chloride solution are applied three times. The saline solution is measured in a measuring cylinder and applied to the diaper in one shot through the ring in the plate. Simultaneously with the task, the time is measured which is necessary for the solution to penetrate completely into the diaper. The measured time is noted as acquisition time 1. The diaper is then loaded with a plate for 20 minutes, the load being kept at 13.6 g / cm ² . Then the second task of the liquid takes place. The measured time is noted as acquisition time 2. The same procedure is used to determine acquisition time 3.

The percentages in the examples mean percent by weight, unless the context indicates otherwise.

example 1 (a) Production of a foam sheet

The following components were mixed in a beaker using a magnetic stirrer:
348.55 g acrylic acid (4.84 mol)
135.51 g of a 37.3% sodium acrylate solution in water (0.54 mol)
28.00 g of polyethylene glycol diacrylate of polyethylene glycol with a molecular weight of 400
21.33 g of a 15% strength aqueous solution of an addition product of 80 mol of ethylene oxide and 1 mol of a linear, saturated C ₁₆ C ₁₈ fatty alcohol
65.70 g water

400.90 g (2.69 mol) were added to this solution while cooling with ice. Triethanolamine added so that the internal temperature does not exceed 16 ° C rise. The solution obtained was put in a pressure vessel transferred and there for 25 min at a pressure of 12 bar Carbon dioxide saturated. 26.67 g of a 3% strength, aqueous solution of 2,2'-azobis (2-amidinopropane) dihydrochloride added and homogeneous with a strong carbon dioxide stream mixed in. Carbon dioxide was then passed through for a further 5 min the reaction mixture passed. The saturated reaction mixture was at a pressure of 12 bar through a nozzle with a Diameter of 1 mm squeezed out, being a fine-celled, good flowable foam formed.

The monomer foam obtained was large on a DIN A3 Glass plate with 3 mm high edges applied and with a second Glass plate covered. The foam sample was synchronized by both Sides with two UV / VIS lamps (UV 1000 from Höhnle) for 4 Irradiated minutes.

The foam layer obtained was completely dried in a vacuum drying cabinet at 70 ° C. To determine the properties, part of the foam was then adjusted to a moisture content of 5% by spraying with water.
Solids content of the reaction mixture: 81.04%
Degree of neutralization: 60 mol%
Monomer foam density: 0.18 g / cm ³
Polymer foam density: 0.19 g / cm ³
Foam structure: homogeneous, completely open-celled, no skin formation
Foam thickness: 3 mm

(b) treating the foam sheet with a skin care product

A 3 mm thick foam sample prepared according to Example 1 (a) with the dimensions 29 × 20 cm was with a 10% commercial dispersion of Aloe BARBADENSIS Leaf. in methanol treated. The foam so impregnated was left overnight Room temperature dried. The content of Aloe BARBADENSIS Leaf. on the Foam surface was approximately 1 g / g. When using this foam sample a skin care effect was found in a hygiene article.

Example 2

On a foam sheet produced according to Example 1 (a) with the Dimensions 290 × 200 × 3 mm was a 5% dispersion of Vitamin A in methanol is applied in such an amount that the Foam film> 1 g / g of vitamin A absorbed on the surface contained. The foam sample treated in this way was left overnight Room temperature dried. Put this sample as Acquisition layer in a hygiene article, so with his Use a steady release of vitamin A instead.

Example 3

Example 2 was repeated with the only exception that one applied a dispersion of vitamin E to the foam sheet. At the Use of a hygiene article that is so equipped Contains foam film as an acquisition layer, finds an ongoing Delivery of vitamin E to the skin instead.

Example 4

Example 2 was repeated with the only exception that one used a 5% dispersion of bisabolol in methanol. At the Use of a hygiene article that is so equipped Contains foam film as an acquisition layer, finds an ongoing Release of bisabolol instead.

Example 5

Example 2 was repeated with the exception that one Dispersion of zinc oxide used. The zinc oxide remained on the Surface of the surface of the foam sheet that when used as Acquisition layer in a hygiene article has a skin-care effect.

Claims (5)

1. Foam-shaped hydrogels based on predominantly open-cell, crosslinked, acidic foam-containing polymers, characterized in that they contain at least one skin care product. 2. Foam-shaped hydrogels according to claim 1, characterized characterized in that it contains at least one compound as a skin care product from the group of perfume oils, plant substances, vitamin A, Contain vitamin E and / or zinc oxide. 3. Foam-shaped hydrogels according to claim 1 or 2, characterized characterized in that they refer to foam hydrogel and skin care products, 5 to 95% by weight of at least one Skin care products included. 4. Process for the preparation of the foam hydrogels claims 1 to 3, characterized in that one foam hydrogels with a solution or Treated dispersion of a skin care product and then that Solvent removed. 5. Use of foam hydrogels according to one of the Claims 1 to 3 for the absorption of body fluids in Hygiene articles with skin care properties.