WO2000076559A1

WO2000076559A1 - Absorbent mixture

Info

Publication number: WO2000076559A1
Application number: PCT/EP2000/004578
Authority: WO
Inventors: Friedrich Engelhardt; Volker Frenz; Norbert Herfert
Original assignee: Basf Aktiengesellschaft
Priority date: 1999-06-10
Filing date: 2000-05-19
Publication date: 2000-12-21
Also published as: DE19926431A1

Abstract

The invention relates to an absorbent mixture that contains (a) an organic iodine compound and (b) a hydrogel-forming polymer, the share of the iodine compound being 0.001 to 5 wt.- % of the hydrogel-forming polymer. The invention also relates to the use of said mixture in incontinence products and to incontinence articles containing said mixture.

Description

Absorbent mixture

description

The present invention relates to an absorbent mixture containing

(a) an organic iodine compound and

(b) a hydrogel-forming polymer,

the proportion of the iodine compound being 0.001 to 5% by weight of the hydrogel-forming polymer and the use of this mixture in incontinence articles for adults and babies and incontinence articles containing them. It also relates to the use of organic iodine compounds in incontinence articles.

Diaper rash is a common manifestation of skin irritation or inflammation in areas of the body that are usually covered by wearing a diaper. In particular, diaper rash is a serious problem in adult incontinence. It is generally accepted that diaper dermatitis is a contact dermatitis caused by long-term skin contact with urine and / or faeces. To date, the exact components in urine and faeces that are responsible for the appearance of diaper rash are not yet fully known. However, it can be assumed that ammonia, bacteria, fungi, moisture and the skin pH play a decisive role in the development of diaper dermatitis. In addition to skin irritation or inflammation, the long-term contact of the skin with urine and fecal matter also leads to the development of malodours, which are particularly unpleasant for adults wearing incontinence articles.

Numerous attempts have been made to solve these two problems.

On the one hand, attempts have been made to cover the smell with fragrances, as described in JP-A-0 605 1843, and on the other hand to bind it with zeolites, as described in WO 95/26207. Such measures reduce the perception of unpleasant smells, but not the occurrence of skin irritation and inflammation. Skin irritation occurs frequently when the skin's natural protective acid mantle is destroyed. This is done by increasing the pH, for example, by decomposing the urea to ammonia by urease.

EP-A 0 739 635 therefore teaches hydrogels containing sodium tetraborate which act as urease inhibitors.

Furthermore, there are numerous attempts to achieve a skin-neutral pH value with a wide variety of diaper parts by using buffer substances or materials bearing acid groups. EP-A-0 316 518 teaches hydrogels which have a pH of 5.2 to 5.5 when wetted with water. Furthermore, ion-exchanging modified cellulose is described in EP-A-0 202 126 as a covering layer and in EP A-0 202 127 as a core material. All of these approaches have in common that the formation of the skin-irritating components is not prevented and the effect wears off with longer contact times.

EP-A-0 837 077, EP-A-0 839 841 and WO 92/06694 describe the use of quaternary ammonium salts, such as cetylpyridinium chloride or didecyldimethylamonium carbonate, as microbicidal additives for the hydrogel. However, it is disadvantageous that these compounds themselves are not very tolerable to the skin and lead to allergic reactions.

The present invention was therefore based on an absorbent mixture as an object which, when used in articles for absorbing body fluids, does not have the disadvantages mentioned above.

Accordingly, the above-mentioned absorbent mixtures were, their use in incontinence articles, and incontinence articles ent ^¬ holding mixtures of the invention found.

An absorbent mixture is to be understood as a mixture which contains a hydrogel-forming polymer as the main constituent. The mixture according to the invention preferably consists of an organic iodine compound, the hydrogel-forming polymer and, if appropriate, additives customary for hydrogel.

Organic iodine compounds (a) are compounds which contain iodine bound covalently or in a complex manner. Such compounds release iodine relatively easily on contact with aqueous liquids. Organic iodine compounds which contain iodine in complex form are, for example, polyvinylpyrrolidone-iodine complex and starch-iodine complexes.

Covalent iodine compounds, in particular 3-iodo-2-propynyl-N-butylcarbamate and 4-methylphenyldiiodomethylsulfone, are particularly preferred.

The proportion of the organic iodine compound based on the total weight of the absorbent mixture is 0.001 to 5% by weight, preferably 0.005 to 1% by weight, in particular 0.01 to 0.5% by weight.

Hydrogel-forming polymers (b) are crosslinked polymers with acid groups which are predominantly in the form of their salts, generally alkali metal or ammonium salts. Such polymers swell to form gels on contact with aqueous liquids.

Polymers (b) which are obtained by crosslinking polymerization or copolymerization of monoethylenically unsaturated monomers bearing acid groups or their salts are preferred. It is also possible to (co) polymerize these monomers without crosslinking agents and to crosslink them subsequently.

Such monomers bearing acid groups are, for example, monoethylenically unsaturated C ₃ -C ₂₅ -carboxylic acids or anhydrides such as acrylic acid, methacrylic acid, ethacrylic acid, α-chloroacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid, aconitic acid and fumaric acid. Also suitable are monoethylenically unsaturated sulfonic or phosphonic acids, for example vinylsulfonic acid, allylsulfonic acid, sulfoethyl acrylate, sulfoethyl methacrylate, sulfopropyl acrylate, sulfopropyl methacrylate, 2-hydroxy-3-acryloxypropylsulfonic acid, 2-hydroxy-3-methacryloxypropylsulfonic acid, vinylphosphonic acid, vinylphosphonic acid, vinylphosphonic acid, vinylphosphonic acid, Acrylamido-2-methylpropanesulfonic acid. The monomers can be used alone or as a mixture with one another.

Preferred monomers are acrylic acid, methacrylic acid, vinylsulfonic acid, acrylamidopropanesulfonic acid or mixtures of these acids, e.g. Mixtures of acrylic acid and methacrylic acid, mixtures of acrylic acid and acrylamidopropanesulfonic acid or mixtures of acrylic acid and vinylsulfonic acid.

To optimize properties, it can make sense to use additional monoethylenically unsaturated compounds which do not have an acid group but can be copolymerized with the monomers bearing acid groups. These include, for example Amides and nitriles of monoethylenically unsaturated carboxylic acids, for example acrylamide, methacrylamide and N-vinylformamide, N-vinyl acetamide, N-methyl-N-vinyl acetamide, acrylonitrile and methacrylonitrile. Other suitable compounds are, for example, vinyl esters of saturated C 1 -C ₄ -carboxylic acids such as vinyl formate, vinyl acetate or vinyl propionate, alkyl vinyl ethers with at least 2 C atoms in the alkyl group, such as ethyl vinyl ether or butyl vinyl ether, esters of monoethylenically unsaturated C ₃ - to Cs carboxylic acids , for example esters from monohydric Cι ~ to Cia alcohols and acrylic acid, methacrylic acid or maleic acid, half esters of maleic acid, for example monomethyl maleate, N-vinyl lactams such as N-vinylpyrrolidone or N-vinylcaprolactam, acrylic acid and methacrylic acid esters of alkoxylated monohydric, saturated alcohols, for example from Alcohols with 10 to 25 carbon atoms, which have been reacted with 2 to 200 moles of ethylene oxide and / or propylene oxide per mole of alcohol, and also monoacrylic acid esters and monomethacrylic acid esters of polyethylene glycol or polypropylene glycol, the molecular weights (M _N ) of the polyalkylene glycols, for example, up to Can be 2000. Other suitable monomers are styrene and alkyl-substituted styrenes such as ethylstyrene or tert. Butyl styrene.

These monomers not bearing acid groups can also be used in a mixture with other monomers, e.g. Mixtures of vinyl acetate and 2-hydroxyethyl acrylate in any ratio. These monomers which do not contain acid groups are added to the reaction mixture in amounts of between 0 and 50% by weight, preferably less than 10% by weight.

Crosslinked polymers of acid groups are preferred monoethylenically unsaturated monomers, which are converted, where appropriate, before or after the polymerization in their alkali or ammonium salts, and from 0 - 40 wt -.%, Based on its Gesamtge ^¬ weight without acid groups are monoethylenically unsaturated monomers.

Crosslinked polymers (b) of monoethylenically unsaturated C ₃ -C ₂ -carboxylic acids and / or their alkali metal or ammonium salts are preferred. In particular, crosslinked polyacrylic acids are preferred, the acid groups of which are 50-100% in the form of alkali or ammonium salts.

Compounds which have at least 2 ethylenically unsaturated double bonds can function as crosslinkers. Examples of compounds of this type are N, N '-methylene-bisacrylamide, polyethylene glycol diacrylates and polyethylene glycol dimethacrylates, which are each derived from polyethylene glycols with a molecular weight of 106 to 8500, preferably 400 to 2000, trimethylol triacrylate, trimethylolpropane tri ethacrylate, ethylene glycol - diacrylate, propylene glycol diacrylate, butanediol diacrylate, hexanediol diacrylate, hexanediol dimethacrylate, allyl methacrylate, diacrylates and dimethacrylates of block copolymers from 5 ethylene oxide and propylene oxide, doubly or triply with acrylic acid or methacrylic acid esterified polyhydric alcohols such as glycerol or pentaerythritol, triallylamine , Tetraallylethylenediamine, divinylbenzene, diallylphthalate, polyethylene glycol divinyl ether of polyethylene glycols with a molecular weight of 126 to

10 4000, tri ethylol propanediallyl ether, butanediol divinyl ether, pentaerythritol triallyl ether and / or divinylethylene urea. Preferably water-soluble crosslinking agents are used, e.g. N, N'-methylene-bisacrylamide, polyethylene glycol diacrylates and polyethylene glycol dimethacrylates, which differ from addition products of 2

Derive 15 to 400 moles of ethylene oxide to 1 mole of a diol or polyol, vinyl ethers of addition products of 2 to 400 moles of ethylene oxide to 1 mole of a diol or polyol, ethylene glycol diacrylate, ethylene glycol dimethacrylate or triacrylates and tri-methacrylates of addition products from 6 to 20 Moles of ethylene oxide

20 to 1 mol of glycerol, pentaerythritol triallyl ether and / or divinyl urea.

Compounds which have at least one polymerizable ethylenically unsaturated group and

25 contain at least one further functional group. The functional group of these crosslinkers must be able to react with the functional groups, essentially the acid groups of the monomers. Suitable functional groups are, for example, hydroxyl, amino, epoxy and aziridino groups.

30 can find use, for example, hydroxyalkyl esters of the above genann ^¬ th monoethylenically unsaturated carboxylic acids, for example ethyl 2-hydroxy-, ethyl methacrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxy methacrylate, hydroxypropyl methacrylate and acrylate Hydroxybutylmeth-, Dialkyldiallylammoniumhalogenide as Dimethyldiallylam-

35 monium chloride, diethyl diallyl ammonium chloride, allyl piperidinium bromide, N-vinylimidazoles such as e.g. N-vinylimidazole, l-vinyl-2-methylimidazole and N-vinylimidazolines such as N-vinylimidazoline, l-vinyl-2-methylimidazoline, l-vinyl-2-ethylimidazoline or l-vinyl-2-propylimidazoline, which are in the form of free bases, in

40 quaternized form or as a salt can be used in the polymerization. Dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates, dirnethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate and diethylaminoethyl methacrylate are also suitable. The basic esters are preferably used in quaternized form or as a salt. Furthermore, glycidyl (meth) acrylate can also be used, for example. The crosslinkers are present in the reaction mixture, for example from 0.001 to 20% by weight and preferably from 0.01 to 14% by weight.

As usual, the polymerization is triggered by an initiator. It is also possible to initiate the polymerization by the action of electron beams on the polymerizable, aqueous mixture. However, the polymerization can also be initiated in the absence of initiators of the type mentioned above by the action of high-energy radiation in the presence of photoinitiators. All compounds which decompose into free radicals under the polymerization conditions can be used as polymerization initiators, for example peroxides, hydroperoxides, hydrogen peroxide, persulfates, azo compounds and the so-called redox catalysts. The use of water-soluble initiators is preferred. In some cases it is advantageous to use mixtures of different polymerization initiators, for example mixtures of hydrogen peroxide and sodium or potassium peroxodisulfate. Mixtures of hydrogen peroxide and sodium peroxodisulfate can be used in any ratio. Suitable organic peroxides are, for example, acetylacetone peroxide, methyl ethyl ketone peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, tert. -Amyl perpivalate, tert-butyl perpivalate, tert. Butyl perneohexanoate, tert. -Butylperisobuty- rat, tert. -Butyl-per-2-ethylhexanoate, tert. Butyl perisononanoate, tert. -Butyl permaleate, tert. -Butyl perbenzoate, di- (2-ethyl-hexyl) -peroxidicarbonate, dicyclohexylperoxydicarbonate, di- (4-tert.-butylcyclohexyl) peroxydicarbonate, dimyristil-peroxydicarbonate, diacetylperoxydicarbona, allyl-perester, cumylperano. -Butylper-3, 5, 5-tri-methylhexanoate, acetylcyclo-clohexyl-sulfonyl peroxide, dilauryl peroxide, dibenzoyl peroxide and tert. -Amylperneodecanoate. Particularly suitable polymerization initiators are water-soluble azo starters, for example 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis (N, N 'dimethyl) isobutyramidine dihydrochloride, 2- (carbamoylazo) isobutyronitrile, 2,2'-azobis [2- (2 '-imidazolin-2-yl) propane] dihydro ^¬ chloride and 4,4'-azobis (4-cyanovaleric acid). The polymerization initiators mentioned are used in customary amounts, for example in amounts of 0.01 to 5, preferably 0.1 to 2.0% by weight, based on the monomers to be polymerized.

Redox catalysts are also suitable as initiators. The redox catalysts contain at least one of the above-mentioned per compounds as the oxidizing component and, for example, ascorbic acid, glucose, sorbose, ammonium or alkali metal hydrogen sulfite, sulfite, thiosulfate, hyposulfite, pyrosulfite or sulfide, metal salts as the reducing component , such as iron (II) ions or silver ions or sodium hydroxymethylsulfoxy lat. Ascorbic acid or sodium sulfite is preferably used as the reducing component of the redox catalyst. Based on the amount of monomers used in the polymerization, for example 3-10 ^-6 to 1 mol% of the reducing component of the redox catalyst system and 0.001 to 5.0 mol% of the oxidizing component of the redox catalyst are used.

If the polymerization is triggered by the action of high-energy radiation, so-called photoinitiators are usually used as initiators. These can be, for example, so-called α-splitters, H-abstracting systems or also azides. Examples of such initiators are benzophenone derivatives such as Michlers ketone, phenanthrene derivatives, fluorene derivatives, anthraquinone derivatives, thioxanone derivatives, coumarin derivatives, benzoin ethers and their derivatives, azo compounds such as the radical formers mentioned above, substituted hexaaryl bisimidazoles or Acylphosphine oxides. Examples of azides are: 2- (N, N-dimethylamino) ethyl 4-azidocinnamate, 2- (N, N-dimethylamino) ethyl 4-azi-donaphthyl ketone, 2- (N, -dimethylamino) - ethyl 4-azidobenzoate, 5-azido-l-naphthyl-2'- (N, N-dimethylamino) ethylsulfone, N- (4-sulfonyl azidophenyl) maleinimide, N-acetyl-4-sulfonyl azidoaniline, 4-sulfonyl azidoaniline , 4-azidoaniline, 4-azidophenacyl bromide, p-azide-topzoic acid, 2,6-bis (p-azidobenzylidene) cyclohexanone and 2,6-bis (p-azidobenzylidene) -4-methylcyclohexanone. If they are used, the photoinitiators are usually used in amounts of 0.01 to 5% by weight, based on the monomers to be polymerized.

In the subsequent crosslinking, polymers which have been prepared by the polymerization of the abovementioned monoethylenically unsaturated acids and, if appropriate, monoethylenically unsaturated comonomers and which have a molecular weight greater than 5000, preferably greater than 50,000, are reacted with compounds which have at least two groups reactive toward acid groups on point. This reaction can be carried out up to 200 ° C at room temperature or else at elevated temperatures it ^¬.

The suitable functional groups have already been mentioned above, i.e. Hydroxyl, amino, epoxy, isocyanate, ester, A ido and aziridino groups. Examples of such crosslinking agents are ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, glycerol, polyglycerol, propylene glycol, polypropylene glycol, block copolymers of ethylene oxide and propylene oxide, sorbitan fatty acid esters, ethoxylated sorbitan fatty acid esters, 3-trimethylol propane, pentaerythritol, pentaerythritol

1,4-butanediol, polyvinyl alcohol, sorbitol, polyglycidyl ethers such as ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, Glycerol diglycidyl ether, glycerol polyglycidyl ether, Diglycerinpo - lyglycidylether, polyglycerol polyglycidyl ether, Sorbitpolyglyci - dylether, pentaerythritol polyglycidyl ether, Propylenglykoldiglyci - dylether and polypropylene glycol, Polyaziridinver- compounds such as 2, 2-bishydroxymethyl butanol-tris [3- (1-aziridinyl) - propionate], 1, 6-hexamethylenediethyleneurea , Diphenylmethane to -4, 4 '-N, N' -diethyleneurea, haloepoxy compounds such as epichlorohydrin and α-methylepifluorohydrin, polyisocyanates such as 2, 4-tolylene diisocyanate and hexamethylene diisocyanate, alkylene carbonates such as 1, 3-dioxolan-2-one and 4 -Methyl-1, 3-dioxolan-2-one, also bisoxazolines and oxazolidones, also polyquaternary amines such as condensation products of dimethylamine with epichlorohydrin, homo- and copolymers of diallyldimethylammonium chloride and homo- and copolymers of dimethylaminoethyl (meth) acrylate, which if appropriate are quaternized with, for example, methyl chloride.

Other suitable crosslinkers for postcrosslinking are polyvalent metal ions, which are able to form ionic crosslinks. Examples of such crosslinkers are magnesium, calcium, barium and aluminum ions. These crosslinkers are added, for example, as hydroxides, carbonates or bicarbonates to the aqueous polymerizable solution. Other suitable crosslinkers are multifunctional bases which are also able to form ionic crosslinks, for example polyamines or their quaternized salts. Examples of polyamines are ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine and polyethylene imines as well as polyvinyl amines with molecular weights of up to 4,000,000 each.

The crosslinking agents are the acid group-bearing polymers or salts in amounts of 0.5 to 25 wt -.% Preferably 1 to 15 wt .-%, based on the amount of the polymer employed supplied ^¬ sets.

The crosslinked polymers (b) are preferably used in neutralized form in the mixture according to the invention. The neutralization ^¬ tion but may be only partial. The degree of neutralization is preferably 25 to 100%, in particular 50 to 100%. Possible neutralizing agents are:

Alkali metal bases or ammonia or amines. Sodium hydroxide solution or potassium hydroxide solution is preferably used. However, the neutralization can also be carried out with the aid of sodium carbonate, sodium hydrogen carbonate, potassium carbonate or potassium hydrogen carbonate or other carbon ten or hydrogen carbonates or ammonia. Furthermore, prim. , sec. and tert. Amines can be used.

All processes which are usually used in the production of superabsorbers, such as are used, for example, can be used as technical processes for producing these products. in Chapter 3 in "Modern Superabsorbent Polymer Technology", F.L. Buchholz and A.T. Graham, Wiley-VCH, 1998.

Polymerization in aqueous solution is preferred as so-called gel polymerization. 10 to 70% by weight aqueous solutions of the monomers and, if appropriate, a suitable graft base are polymerized in the presence of a radical initiator using the Trommsdorff-Norrish effect.

The polymerization reaction can be carried out in the temperature range between 0 and 150.degree. C., preferably between 10 and 100.degree. C., both under normal pressure and under elevated or reduced pressure. As usual, the polymerization can also be carried out in a protective gas atmosphere, preferably under nitrogen.

By heating the polymer gels for several hours in the temperature range from 50 to 130 ° C., preferably from 70 to 100 ° C., the quality properties of the polymers can be improved still further.

Suitable polymers (b) are also graft (co) polymers of one or more hydrophilic monomers on a suitable graft base, crosslinked cellulose or starch ethers and esters containing acid groups, crosslinked carboxymethyl cellulose, or natural products with acid groups which are swellable in aqueous liquids, such as alginates and carrageenans.

Suitable graft bases can be of natural or synthetic origin. Examples are starch, cellulose or cellulose derivatives and other polysaccharides and oligosaccharides, polyvinyl alcohol, polyalkylene oxides, in particular polyethylene oxides and polypropylene oxides, polyamines, polyamides and hydrophilic polyesters. Suitable polyalkylene oxides have, for example, the formula

X

R ¹ -O- (CH ₂ -CH-0) _n -R '

wherein R ¹ and R ² independently of one another are hydrogen, alkyl, alkenyl or aryl,

X is hydrogen or methyl and

n is an integer from 1 to 10,000.

R ¹ and R ^{2 are} preferably hydrogen, (C ₁ -C ₄ ) alkyl, (C -C ₆ ) alkenyl or phenyl.

Hydrogel-forming polymers (b) which are post-crosslinked are preferred. The surface postcrosslinking can take place in a manner known per se with dried, ground and sieved polymer particles.

For this purpose, compounds which can react with the functional groups of the polymers (b) with crosslinking are preferably applied to the surface of the hydrogel particles in the form of a water-containing solution. The water-containing solution can contain water-miscible organic solvents. Suitable solvents are alcohols such as methanol, ethanol, i-propanol or acetone.

Suitable post-crosslinking agents are, for example

Di- or polyglycidyl compounds such as phosphonic acid diglycidyl ether or ethylene glycol diglycidyl ether, bischlorohydrin ether of polyalkylene glycols,

Alkoxysily1 compounds,

Compounds containing polyaziridines, 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, sorbitol, the oxyethylates of these polyols and their esters with carboxylic acids or carbonic acid 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,

If necessary, acidic catalysts such as p-toluenesulfonic acid, phosphoric 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 and 2-0xazolidinone, which can react with carboxyl groups with crosslinking.

The crosslinking agent solution is preferably applied by spraying on a solution of the crosslinking agent in conventional reaction mixers or mixing and drying systems. After the crosslinking agent solution has been sprayed on, a temperature treatment step can follow, preferably in a downstream dryer, at a temperature between 80 and 230 ° C, preferably 80-190 ° C, and particularly preferably between 100 and 160 ° C, over a period of 5 minutes to 6 Hours, preferably 10 minutes to 2 hours and particularly preferably 10 minutes to 1 hour, it being possible for both cleavage products and solvent fractions to be removed. Drying can also take place in the mixer itself, by heating the jacket or blowing in a preheated carrier gas.

In a particularly preferred embodiment of the invention, the hydrophilicity of the particle surface polymer (b) is additionally modified by the formation of complexes. The complexes are formed on the outer shell of the hydrogel particles by spraying on solutions of divalent or polyvalent metal salt solutions, the metal cations being able to react with the acid groups of the polymer to form complexes. Examples of divalent or polyvalent metal cations are Mg ²⁺ , Ca ²⁺ , Al ³⁺ , Sc ³⁺ , Ti ⁺ , Mn ²⁺ , Fe ²⁺ / ³⁺ , Co ²⁺ , Ni ²⁺ , Cu ⁺ / ²⁺ , Zn ⁺ , Y ³⁺ , Zr ⁺ , Ag ⁺ , La ³⁺ , Ce ⁴⁺ , Hf ⁴⁺ , and Au ⁺ / ³⁺ , preferred metal cations are Mg ²⁺ , Ca ²⁺ , Al ³⁺ , Ti ⁴⁺ , Zr ⁴⁺ and La ³⁺ , and particularly preferred metal cations are Al ³⁺ , Ti ⁴⁺ and Zr ⁴⁺ . Of the metal cations mentioned, all salts are suitable which have sufficient solubility in the solvent to be used. Water, alcohols, DMF, DMSO and mixtures of these components can be used as solvents for the salts. Water and water / alcohol mixtures such as water / methanol or water / 1, 2-propanediol are particularly preferred.

The salt solution can be sprayed onto the particles of the hydrogel-forming polymer both before and after the surface post-crosslinking of the particles. In a particularly preferred method, the salt solution is sprayed on in the same step as the spraying of the crosslinking agent solution, with both solutions being sprayed on separately in succession or simultaneously via two nozzles, or the crosslinking agent and salt solution being sprayed together via a nozzle.

The organic iodine compound can be introduced into the absorbent mixture already during the production of the polymer (b). It can be added before, during or after the polymerization. Liquid iodine compounds are preferably applied together with the surface postcrosslinking solution. Preferably, the iodine compound is optionally applied as a solution after the surface postcrosslinking step, for example sprayed on by means of a nozzle. Organic iodine compounds, particularly as a solid, are likewise preferably mixed directly with the powder of the hydrogel-forming polymer.

The resulting hydrogel-forming polymer contains the organic iodine compound evenly distributed or reinforced on its surface, depending on the time of addition. Hydrogel whose surface has been treated with the organic iodine compound is particularly preferred.

In a preferred embodiment of the invention, the absorbent mixture contains phenoxyethanol as an additive. The concentration of the phenoxyethanol is 0.001 to 5% by weight, preferably 0.01 to 2% by weight, in particular 0.05 to 1% by weight, based on the total weight of the absorbent mixture. The phenoxyethanol can be introduced similarly to the iodine compound.

In a further preferred embodiment, borates, preferably sodium tetraborate and / or boric acid, are added to the mixture in amounts of from 0.01 to 10% by weight, preferably 0.1 to 5% by weight. based on the total mixture of the absorbent mixture added.

Absorbent mixtures are preferred whose pH is from 3 and 7, preferably from 4 to 6 and in particular from 4.5 to 6.

Optionally, a further modification of the particles of polymer (b) can be carried out by admixing finely divided inorganic solids, such as, for example, silica, bentonite, aluminum oxide, titanium dioxide and iron (II) oxide, which further enhances the effects of surface treatment. The addition of hydrophilic silica or of aluminum oxide with an average size of the primary particles of 4 to 50 nm and a specific surface area of 50-450 m ² / g is particularly preferred. The addition of finely divided inorganic solids is preferably carried out after the surface modification by crosslinking / complex formation, but can also be carried out before or during these surface modifications.

The absorbent mixtures according to the invention have good fungicidal and bactericidal properties. The incontinence articles contain a good skin tolerance.

The present invention further relates to the use of the above-mentioned organic iodine compounds in incontinence articles.

The present invention further relates to incontinence articles comprising

(A) an upper liquid permeable cover

(B) a lower liquid impervious layer

(C) containing a core located between (A) and (B)

(Cl) 30-100% by weight of the absorbent mixture according to the invention

(C2) 0 - 70% by weight of hydrophilic fiber material

(D) optionally a tissue layer and immediately above and below the core (C)

(E) optionally a receiving layer located between (A) and (C). Incontinence articles mean incontinence pads and incontinence pants for adults as well as diapers for babies.

5 The liquid-permeable cover is the layer that has direct skin contact. The material is conventional synthetic and semi-synthetic fibers or films such as polyester, polyolefins, rayon or natural fibers such as cotton. In the case of non-woven materials, the fibers are usually connected by binders such as polyacrylates. Preferred materials are polyester, rayon and their blends, polyethylene and polypropylene.

The liquid-impermeable layer (B) generally consists of a film made of polyethylene or polypropylene.

In addition to the mixture (Cl) according to the invention, the core (C) contains hydrophilic fiber material (C2). Hydrophilic is understood to mean that aqueous liquids quickly dissolve over the fiber.

20 parts. Usually the fiber material is cellulose, modified cellulose, rayon, polyester such as polyethylene terephthalate. Cellulose fibers such as cellulose are particularly preferred. The fibers generally have a diameter of 1 to 200 μm, preferably 10 to 10 μm. In addition, the fibers have a minimum length

25 by 1 mm.

The proportion of the hydrophilic fiber material based on the total amount of the core is preferably 20-70% by weight, particularly preferably 40-70% by weight. 30

The structure and shape of diapers is generally known and is described, for example, in EP-A-0 316 518 and EP-A-0 202 127.

35 The following examples are intended to explain the invention in more detail.

Description of the test methods:

Measurement of the pH value:

40

100 ml of 0.9% by weight NaCl solution is stirred in a 150 ml beaker with a magnetic stirrer at a moderate speed without air being drawn into the solution. 0.5 + 0.001 g of absorbent mixture are added to this solution and

45 stirred for 10 minutes. After 10 minutes, the pH of the solution is measured using a pH glass electrode, the value is only read when it is stable, but at the earliest after 1 minute.

Determination of the microbicidal effectiveness:

1 g absorbing mixture is mixed with 100 ml synthetic urine replacement solution and 0.1 ml germ solution (approx. 1 - 5 x 10 ⁸ CFU per ml germ suspension) is added. The synthetic urine replacement solution contains 0.64 g CaCl ₂ , 1.14 g MgSO ₄ × 7 H ₂ O, 8.20 g NaCl and 20.0 g urea per 1000 ml demineralized water. The contaminated test solution is incubated at 37 ° C. with shaking at 100 rpm in a water bath. At the time of 0 minutes, after 6 and 23 hours, 10 ml of contaminated test solution are mixed with 90 ml of caso broth and inactivating substances. 1 ml of the inactivation broth is mixed with Caso-Agar and 0.1 ml of Inactivation-Bouil - Ion is spatulated out on Caso-Agar + HLT.

example 1

3600 g of demineralized water and 1400 g of acrylic acid are placed in a polyethylene vessel with a capacity of 10 l, which is well insulated by foamed plastic material. Now 7.5 g of tetraallyloxyethane and 1.7 g of 4-methylphenyl - diiodomethylsulfone are added. At a temperature of 4 ° C., the initiators, consisting of 2.2 g of 2,2′-azobisamidino-propanedihydrochloride, dissolved in 20 g of demineralized water, 4 g of potassium peroxodisulfate, dissolved in 150 g of demineralized water and 0.1 4 g of ascorbic acid, dissolved in 20 g of demineralized water, added in succession and stirred. The reaction solution is then left to stand without stirring

As the temperature rises to approx. 92 ° C, a firm gel forms. This is then mechanically crushed and adjusted to a pH of 5.5 by adding 25% by weight sodium hydroxide solution. The gel is then dried, ground and sieved to a particle size distribution of 100-850 μm. 1 kg of this dried hydrogel is sprayed in a ploughshare mixer with a solution consisting of 25 g of deionized water, 40 g of methanol and 20 g of a 15% strength by weight aqueous solution of a polyamidoamine-epichlorohydrin adduct (RETEN 204 LS from Hercules) and then annealed at 140 ° C for 60 minutes. The microbicidal activity of the product described here was determined (Table 1):

Table 1: Content of colony-forming units (CFU) per ml test solution depending on the incubation period

Example 2

3500 g of demineralized water and 1500 g of acrylic acid are placed in a polyethylene vessel with a capacity of 10 l, which is well insulated by foamed plastic material. Now 4.5 g of methylenebisacrylamide are added. At a temperature of 2 ° C., the initiators, consisting of 2.0 g of 2,2′-azobisidimino-propanedihydrochloride, dissolved in 20 g of demineralized water, 4.4 g of potassium peroxodisulfate, dissolved in 150 g of demineralized water, and the like 0.8 g ascorbic acid dissolved in 20 g deionized water, according to another ^¬ added and stirred. The reaction solution is then left to stand without stirring, wherein sation by incipient Polymeri ^¬, during which the temperature rose to about 98 ° C to ^¬ rises, a solid gel is formed. This is then comminuted mechanically and adjusted to a pH of 4.5 by adding 50% by weight sodium hydroxide solution. The gel is then getrock ^¬ net, ground and classified to a particle size distribution of 100 - micron sieved 850th 600 g of this dried hydrogel is mixed in a Petterson & Kelly mixer with a solution consisting of 0.2 g of ethylene glycol diglycidyl ether, 0.8 g of 4-methylphenyldiiodomethyl sulfone, 3.0 g of phenoxyethanol, 22.5 g of isopropanol and 22 sprayed 5 g ent ^¬ deionised water and then heated for 45 minutes at 120 ° C. The microbicidal activity of the presently-described ^¬ nen product was determined (Table 2).

Table 2 Content of colony-forming units (CFU) per ml test solution depending on the incubation period

Example 3

In a polyethylene vessel with a capacity of 30 l, well insulated by foamed plastic material, 14340 g of demineralized water and 30 g of pentaerythritol allyl ether are introduced as a copolymer crosslinking agent, 5170 g of sodium bicarbonate are suspended therein and 5990 g of acrylic acid are slowly metered in so that the reaction solution is not over-foamed. which cools down to a temperature of approx. 3 - 5 ° C. The initiators, 6.0 g of 2, 2'-azobisamide propane dihydrochloride, are dissolved at a temperature of 4 ° C., 60 g of demineralized water, 12 g of potassium peroxodisulfate, 450 m of demineralized water, and 1.2 g of ascorbic acid, dissolved in 50 m g of demineralized water, added in succession and stirred well. The reaction solution is then left to stand without stirring, a gel being formed by substitutional polymerization, the course of which increases the temperature to about 85 ° C. This rd then w m a kneader überfuhrt, with 16 g of 4-methylphenyl-dιιodomethylsul - fon and 180 g sodium tetraborate added, homogeneously kneaded kleinert zer ^¬, in an air stream at 170 ° C dried, ground and sieved overall. 1 kg of this product was sprayed in a ploughshare mixer with a solution of 2 g of polyglycine polyglycidyl ether (Denacol EX-512 from Nagase Chemicals Ltd.), 0.3 g of citric acid, 60 g of demineralized water and 40 g of 1,2-propanediol and then 40 minutes annealed at 150 ° C for a long time. The microbicidal activity of the product described here, which has a pH of 6.0, was determined (Table 3). Table 3 Content of colony-forming units (CFU) per ml of test solution depending on the incubation period

Comparative Example 1

The procedure is as in Example 1, but no 4-methylphenyl-diiodomethylsulfone is added to the monomer solution. The microbicidal activity of the product was determined (Table VI)

Table VI Colony-forming unit (CFU) content per ml of test solution as a function of the incubation period

In contrast to the hydrogel obtained in the comparative example, the hydrogels obtained according to Examples 1 to 3 are distinguished by excellent microbicidal activity and are therefore outstandingly suitable as absorbents for water and aqueous liquids, in particular body fluids such as, for. B. urine or blood suitable, for example in hygiene articles such. B. Baby and adult diapers.

Example 4

3600 g of demineralized water and 1400 g of acrylic acid are placed in a polyethylene vessel with a capacity of 10 l, which is well insulated by foamed plastic material. Now 7.5 g of tetraallyloxyethane and 1.4 g of 3-iodo-2-propynylbutylcarbama are added. At a temperature of 4 ° C, the initia- gates, consisting of 2.2 g of 2,2'-azobisamidino-propanedihydrochloride, dissolved in 20 g of deionized water, 4 g of potassium peroxodisulfate, dissolved in 150 g of deionized water and 0.4 g of ascorbic acid, dissolved in 20 g of deionized water, added and stirred in succession. The reaction solution is then left to stand without stirring, a solid gel being formed by the onset of polymerization, in the course of which the temperature rises to approximately 92 ° C. This is then mechanically crushed and adjusted to a pH of 5.5 by adding 25% sodium hydroxide solution. The gel is then dried, ground and sieved to a particle size distribution of 100-850 μm. 1 kg of this dried hydrogel is sprayed in a ploughshare mixer with a solution consisting of 25 g of deionized water, 40 g of methanol and 20 g of a 15% strength by weight aqueous solution of a polyamidoamine-epichlorohydrin adduct (RETEN 204 LS from Hercules) and then annealed at 140 ° C for 60 minutes. The microbicidal activity of the product described here was determined (Table 4).

Table 4 Colony-forming unit (CFU) content per ml of test solution as a function of the incubation period

Example 5

3500 g of demineralized water and 1500 g of acrylic acid are placed in a polyethylene vessel with a capacity of 10 l, which is well insulated by foamed plastic material. Now 4.5 g of methylene bisacrylamide are added. At a temperature of 2 ° C., the initiators, consisting of 2.0 g of 2,2′-azobisami-dino-propanedihydrochloride, are dissolved in 20 g of demineralized water.

4.4 g of potassium peroxodisulfate, dissolved in 150 g of deionized water and 0.8 g of ascorbic acid, dissolved in 20 g of deionized water, were added in succession and stirred. The reaction solution is then left to stand without stirring, a solid gel being formed by the onset of polymerization, in the course of which the temperature rises to approximately 98 ° C. This is then crushed mechanically and by adding 50% by weight sodium hydroxide solution adjusted to a pH of 4.5. The gel is then dried, ground and sieved to a particle size distribution of 100-850 μm. 600 g of this dried hydrogel is mixed in a Petterson & Kelly mixer with a solution consisting of 0.2 g of ethylene glycol diglycidyl ether, 0.6 g of 3-iodo-2-propynylbutyl carbamate, 3.0 g of phenoxyethanol and 22.5 g Sprayed i-propanol and 22.5 g of deionized water and then annealed at 120 ° C for 45 minutes. The microbicidal activity of the product described here was determined (Table 5).

Table 5: Content of colony-forming units (CFU) per ml test solution depending on the incubation period

Example 6

14340 g of demineralized water and 30 g of pentaerythritol triallyl ether are placed as copolymerization crosslinkers in a polyethylene vessel with a capacity of 30 l, which is well insulated by foamed plastic material, 5170 g of sodium bicarbonate are suspended therein and 5990 g of acrylic acid are slowly metered in so that the reaction solution is not over-foamed. which cools down to a temperature of approx. 3 - 5 ° C. At a temperature of 4 ° C, the initiators, 6.0 g of 2,2'-azobisamidinopropane dihydrochloride, dissolved in 60 g of demineralized water, 12 g of potassium peroxodisulfate, dissolved in 450 g of demineralized water, and 1.2 g of ascorbic acid, dissolved in 50 g of demineralized water, added in succession and stirred well. The reaction solution is then left to stand without stirring, a gel being formed by the onset of polymerization, in the course of which the temperature rises to approximately 85 ° C. This is then transferred to a kneader, mixed with 18 g of 3-iodo-2-propynylbutyl carbamate and 180 g of sodium tetraborate, kneaded homogeneously, crushed, dried in an air stream at 170 ° C., ground and sieved. 1 kg of this product was mixed in a ploughshare mixer with a solution of 2 g of polyglycerol polyglycidyl ether (Denacol EX-512 from Nagase Chemicals Ltd.), 0.3 g of citric acid, 60 g of demineralized water. water and 40 g of 1, 2-propanediol and sprayed for 40 minutes at 150 ° C. The microbicidal activity of the product described here, which has a pH of 6.0, was determined (Table 6).

Table 6: Content of colony-forming units (CFU) per ml test solution depending on the incubation period

Comparative Example 2

The procedure is as in Example 4, but no 3-iodo-2-propynylbutyl carbamate is added to the monomer solution. The microbicidal effectiveness of the product was determined (Table V2).

Table V2: Content of colony-forming units (CFU) per ml test solution depending on the incubation period

In contrast to the hydrogel obtained in Comparative Example V2, the hydrogels obtained according to Examples 4 to 6 are distinguished by excellent microbicidal activity and are therefore outstandingly suitable as absorbents for water and aqueous liquids, in particular of body fluids such as e.g. B. urine or blood, for example m hygiene items such. B. baby and adult diapers and the like.

Claims

claims

1. Absorbent mixture containing

(a) an organic iodine compound and

(b) a hydrogel-forming polymer,

the proportion of the iodine compound being 0.001 to 5% by weight of the hydrogel-forming polymer.

2. Absorbent mixture according to claim 1, consisting of

(a) an organic iodine compound and

(b) a hydrogel-forming polymer

and optionally additives customary for hydrogel.

3. Absorbent mixture according to claim 1 or 2, characterized in that the hydrogel-forming polymer is a crosslinked polymer composed of acid-bearing monoethylenically unsaturated monomers which are optionally converted into their alkali metal or ammonium salts before or after the polymerization, and 0 - 40% by weight, based on its total weight, is not monoethylenically unsaturated monomers bearing acid groups.

4. Absorbent mixture according to claims 1 to 3, characterized in that the hydrogel-forming polymer is a crosslinked polymer of monoethylenically unsaturated C ₃ -Ci ₂ carboxylic acids and / or their alkali metal or ammonium salts.

5. Absorbent mixture according to claims 1 to 4, characterized in that the organic iodine compound

3-iodo-2-propynyl-N-butyl carbamate or 4-methylphenyldiiodomethylsulfone.

6. Use of organic iodine compounds in incontinence articles.

7. Hydrogel-forming polymer, the surface of which was treated with 0.001 to 5% by weight of organic iodine compound, based on the polymer.

8. Use of absorbent mixtures according to claims 1 to 5 in incontinence articles.

9. Including incontinence articles

(A) an upper liquid permeable cover

(B) a lower liquid impervious layer

(C) containing a core located between (A) and (B)

(Cl) 30-100% by weight of an absorbent mixture according to claims 1-5

(C2) 0 - 70% by weight of hydrophilic fiber material

(D) optionally a tissue layer and immediately above and below the core (C)

(E) optionally a receiving layer between (A) and (C).