WO2022171550A1

WO2022171550A1 - Nonwoven fabric made of a chemically reinforced fibrous web with pu binders, and production thereof

Info

Publication number: WO2022171550A1
Application number: PCT/EP2022/052804
Authority: WO
Inventors: Marc-Stephan Weiser; Thomas Leucht
Original assignee: Covestro Deutschland Ag; Weber & Leucht Gmbh
Priority date: 2021-02-11
Filing date: 2022-02-07
Publication date: 2022-08-18

Abstract

The invention relates to a medical article, containing at least one polymer nonwoven fabric (A) and at least one polyurethane binder (B), at least a part of the polymer nonwoven fabric (A) being surrounded by the polyurethane binder (B).

Description

Non-woven fabric made from chemically bonded fiber pile with PU binders and its manufacture

The invention relates to an article, preferably a nonwoven fabric, which can preferably be used in medical articles, containing at least one fiber material in the form of a polymer fiber web (A) and at least one polyurethane binder (B), formed from a polyurethane dispersion (D) , for the chemical bonding of the fibrous web, wherein at least part of the polymer fibrous web (A) is surrounded by the polyurethane binder (B) or is in contact with it.

Nowadays, more and more disposable items are used, especially in the medical field. One reason for this trend is the high hygiene requirements and standards that prevail in medical applications in particular. Further requirements for articles that are to endure in medical applications are sufficient robustness, low fiber fly, mechanical resistance and, in some cases, high absorbency, particularly when used as hygiene articles or as wound care or wound treatment articles. On the other hand, especially in the clothing sector such as gowns, masks, hoods, etc., the articles should be light and comfortable to wear. Even if there are already many textiles on the market that fulfill these tasks to a certain extent, there is a constant need for improvement. In the state of the art, fleeces strengthened by acrylate binders or non-chemically strengthened fleeces are used for such articles. The main disadvantages here are the lack of firmness, the low elasticity and elongation, and the often insufficient requirement for comfortable wearing properties. While other chemical bonding processes are often unsuitable for medical applications due to fiber flight, the systems for thermal bonding processes are very expensive and therefore do not allow easy market access. In addition, specific properties are difficult or impossible to set, since the fleece properties depend solely on the fiber material.

It was therefore an object of the invention to provide an article, in particular a medical article, which at least partially meets the aforementioned requirements better than conventional articles in the field.

A further object of the invention was to provide an article, in particular a medical article, which has sufficient strength to meet as many requirements as possible of preferably medical textiles, such as low weight, high elasticity, good elongation with pleasant wearing comfort.

Furthermore, it was an object of the invention to provide a method in order to provide an article with the requirements described above as cost-effectively as possible. A first subject of the invention relates to an article, in particular a medical article, preferably a fiber structure, particularly preferably a nonwoven fabric, in particular for medical applications, containing at least one polymer fiber web (A) and at least one polyurethane binder (B), with at least one Part of the polymer fiber web (A) is surrounded by the polyurethane binder (B) or is in contact with it.

The polymer batt (A) can be any polymer batt that one skilled in the art would employ for the article. The polymer batt (A) preferably has fibers in an amount in a range from 70 to 98.5% by weight, based on the total weight of the polymer batt (A).

According to the invention, being in contact means that the fibers of the polymer fiber web (A) are at least partly, if possible for the most part, in contact with the polyurethane binder (B) in such a way that they do not separate or separate when the article is used detach from the item. It is preferred that as many fibers as possible of the polymer fiber web (A), preferably at least 50% of the polymer fiber web (A), are in contact with the polyurethane binder (B) in such a way that little fiber fly, preferably represented as IPM Value, for example, determined using DIN EN ISO 9073-10-2005-03, from which the article is created.

In a preferred embodiment of the article, the polymer batt (A) is selected from the group consisting of a natural polymer or a synthetic polymer or a combination thereof. In addition to pure natural polymers or synthetic polymers, mixtures of natural and synthetic polymers can also be used. The polymer fiber batt (A) preferably contains at least a portion of natural polymers.

In a preferred embodiment of the article, the polymer fiber web (A) is selected from the group consisting of a natural polymer, in particular from the group consisting of cellulose, cotton, hemp fiber, bamboo fiber, flax fiber, wool fiber and viscose, in particular viscose fiber or a mixture of at least two of these. The polymer fiber web (A) preferably contains cotton or viscose or consists of cotton or viscose or a mixture of the two.

In a preferred embodiment of the article, the polymer fiber web (A) is selected from the group consisting of a synthetic polymer, in particular from the group consisting of polyurethane (PU), polyester, preferably a polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) , a synthetically modified cellulose derivative, polypropylene (PP), polyamide (PA), polyethylene (PE), vinyl acetate, aramid fibers and acrylate or a mixture of at least two of these. Polyesters and synthetically modified celluloses are preferably used. In certain applications of the article, it can be preferred that the polymer fiber batt (A) has a combination of natural and synthetic polymers. It is particularly preferred that part of the polymer fiber batt (A) consists of natural fibers and part of synthetic fibers. Mixtures are preferably selected from the group of cellulose, cotton from the group of natural fibers with one or more synthetic fibers selected from the group consisting of polyester, preferably a polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), a synthetically modified cellulose derivative and Polypropylene (PP) or a mixture of at least two of them. Particularly preferred mixture combinations are, for example, 40 to 85% polyester fibers and 10 to 50% cellulose derivative fibers for absorbent nonwovens. Thermoplastic fiber components are often also included for stabilization, for example polyethylene or polypropylene fibers, usually with a weight component of between 5 and 25%.

In a preferred embodiment of the article, at least part of the polyurethane binder (B) is in contact with at least 50%, preferably with at least 70%, particularly preferably with at least 90% of the fibers of the polymer fibrous web (A). The extent of the contact between the polymer fibrous web (A) and the polyurethane binder (B) can be determined by means of microscopy, in particular AFM (atomic force microscopy). Another way to prevent fiber flight is to completely surround the polymer fiber web (A) on its outer surface with polyurethane binder (B). The polyurethane binder (B) forms a kind of protective cover that prevents fibers from escaping.

In a preferred embodiment of the article, the polymer fiber batt (A) has at least one of the following properties:

(A1) Heat resistance in a range from +50 to +400° C., more preferably from +60 to +300° C., particularly preferably from +80 to +200° C., determined according to DIN EN 11280-1:2998;

(A2) consists of fibers which have a fineness in a range from 0.6 to 2.4 dtex, more preferably from 0.8 to 2.2 dtex, particularly preferably from 1.0 to 2.0 dtex, measured according to DIN EN ISO 1973: 1995;

(A3) is suitable for carded, spunlace, meltblown or airlaid nonwoven materials regardless of the dimension and orientation of the fiber;

(A4) consists of fibers having a length to width ratio of from 1:1 to 1:10, more preferably from 1:1 to 1:5, most preferably from 1:1.5 to 1:4;

(A5) consists of fibers containing polyester, polyamide or cellulose derivatives, in particular synthetic cellulose fibers.

The polymer fiber web (A) preferably has the combination of properties selected from the group consisting of (A1) and (A2), (A1) and (A3), (A1) and (A4), (A1) and (A5), ( A2) and (A3), (A2) and (A4), (A2) and (A5), (A3) and (A4), (A3) and (A5), (A4) and (A5), (A1) and (A2) and (A3), (A1 ) and (A2) and (A4), (Al) and (A2) and (A5), (Al) and (A3) and (A4), (Al) and (A3) and (A5), (Al) and (A4) and (A5), (A1) and (A2) and (A3) and (A4), (A1) and (A2) and (A3) and (A5), (A1) and (A2) and (A4 ) and (A5), (Al) and (A3) and (A4) and (A5), (A2) and (A3) and (A4) and (A5), or (Al) and (A2) and (A3) and (A4) and (A5).

The various fleece materials under item (A3) are well known to the person skilled in the art from the prior art.

The length to width ratio in item (A4) is determined by relating the average length of the fibers to their average thickness. The fibers of the polymer fiber batt (A) preferably have an average length in a range from 15 mm to 40 mm, particularly preferably in a range from 20 mm to 30 mm.

The polyurethane binder (B) contains at least one polyurethane. Depending on the organic diisocyanates used, the polyurethane can have an aliphatic or aromatic character. Polyurethanes usually have a block or segment structure. A basic distinction is made between hard segments and soft segments. Hard segments are formed from the organic diisocyanates used for the reaction and short-chain compounds having two to three hydroxyl, amino, thiol or carboxyl groups, preferably compounds having two hydroxyl, amino, thiol or carboxyl groups, particularly preferably diols, with a middle Molecular weight from 60 to 500 g/mol. Soft segments are formed from the organic diisocyanates used for the reaction to form the polyurethane and long-chain compounds with two to three hydroxyl, amino, thiol or carboxyl groups, preferably compounds with two hydroxyl, amino, thiol or carboxyl groups, particularly preferably diols an average molecular weight of > 500 and < 5000 g/mol.

Hard segments contribute strength and upper service temperatures to the polyurethane property profiles, soft segments control the elastic properties of the polyurethane binder (B).

Aromatic, aliphatic, araliphatic, heterocyclic and cycloaliphatic diisocyanates or mixtures of these diisocyanates can be used as organic diisocyanates for both the hard segments and the soft segments (cf. HOUBEN-WEYL "Methods of Organic Chemistry", Volume E20 "Macromolecular Substances", Georg Thieme Verlag, Stuttgart, New York 1987, pp. 1587-1593 or Justus Liebigs Annalen der Chemie, 562, pages 75 to 136).

Specific examples include: aliphatic diisocyanates such as hexamethylene diisocyanate (HDI), cycloaliphatic diisocyanates such as isophorone diisocyanate (IPDI), 1,4-cyclohexane diisocyanate, 1-methyl -2, 4-cyclohexane diisocyanate and 1-methyl -2, 6-cyclohexane diisocyanate and the corresponding isomer mixtures, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate and 2,2'-dicyclohexylmethane diisocyanate and the corresponding isomer mixtures, aromatic diisocyanates such as 2,4-tolylene diisocyanate, mixtures of 2,4- Tolylene diisocyanate and 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate and 2,2'-diphenylmethane diisocyanate, mixtures of 2,4'-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate, urethane-modified liquid 4 ,4'-diphenylmethane diisocyanates and 2,4'-diphenylmethane diisocyanates, 4,4'-diisocyanatodiphenylethane-(1,2) and 1,5-naphthylene diisocyanate. Preference is given to using 1,6-hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, diphenylmethane diisocyanate isomer mixtures with a 4,4'-diphenylmethane diisocyanate content of >96% by weight and in particular 4,4'-diphenylmethane diisocyanate and 1 ,5-naphthylene diisocyanate. The diisocyanates mentioned can be used individually or in the form of mixtures with one another. They can also be used together with up to 15% by weight (calculated on the total amount of diisocyanate) of a polyisocyanate, for example triphenylmethane-4,4',4"-triisocyanate or polyphenylpolymethylene polyisocyanates. Examples of particularly preferred organic diisocyanates are 4,4'-diphenylmethane diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate (HDI), especially hexamethylene diisocyanate (HDI).

The preferred short-chain diols with a molecular weight of 60 to 500 g/mol are preferably aliphatic diols having 2 to 14 carbon atoms, for example ethanediol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol , 1,5-pentanediol, 1,6-hexanediol,

diethylene glycol and dipropylene glycol. Also suitable, however, are diesters of terephthalic acid with glycols having 2 to 4 carbon atoms, e.g. ethoxylated bisphenols, for example 1,4-di(β-hydroxyethyl)bisphenol A, (cyclo)aliphatic diamines such as isophoronediamine, ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, N-methyl-1,3-propylene diamine, N,N'-dimethylethylenediamine and aromatic diamines such as 2,4-tolylenediamine, 2,6-tolylenediamine, 3,5-diethyl-2,4-tolylenediamine or 3,5-diethyl-2,6-tolylenediamine or primary mono- , di-, tri- or tetra-alkyl substituted 4,4'-diaminodiphenylmethanes. Particularly preferred are ethanediol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, ethylene glycol,

diethylene glycol, 1,4-di(β-hydroxyethyl)hydroquinone or 1,4-di(β-hydroxyethyl)bisphenol A is used. Mixtures of the abovementioned compounds can also be used. In addition, smaller amounts of triols can also be added.

The long-chain compounds with two to three hydroxyl, amino, thiol or carboxyl groups, preferably compounds with two hydroxyl, amino, thiol or carboxyl groups, particularly preferably diols, with a number average molecular weight of >500 and <5000 g/mol can be divided into two main groups: polyether diols and polyester diols. The polyether diols are based for example on polytetrahydrofuran, polyethylene oxide and polypropylene oxide and mixtures thereof. The polyester diols are typically based on adipates such as 1,4-butanediol adipate and 1,6-hexanediol adipate and caprolactone. Co-condensates are also possible.

Conventional catalysts known from the prior art can be used in the production of the TPU. These can be tertiary amines such as triethylamine, dimethylcyclohexylamine, N-methylmorpholine, N,N'-dimethylpiperazine, 2-(dimethylamino-ethoxy)ethanol, diazabicyclo[2.2.2]octane and the like, and in particular organic metal compounds such as Titanic acid esters, iron compounds or tin compounds such as tin diacetate, tin dioctoate, tin dilaurate or the tin dialkyl salts of aliphatic carboxylic acids such as dibutyltin diacetate or dibutyltin dilaurate or the like. Preferred catalysts are organic metal compounds, especially titanic acid esters, iron and tin compounds. The total amount of catalysts in the polyurethanes can generally be about 0 to 5% by weight, preferably 0 to 2% by weight, based on the total amount of polyurethane.

Furthermore, the polyurethanes can contain auxiliaries and additives up to a maximum of 20% by weight, based on the total amount of polyurethane. Typical auxiliaries and additives are pigments, dyes, flame retardants, stabilizers against the effects of aging and weathering, plasticizers, lubricants and mold release agents, fungistatic and bacteriostatic substances, and fillers and mixtures thereof.

Examples of other additives are lubricants, such as fatty acid esters, their metal soaps, fatty acid amides, fatty acid ester amides and silicone compounds, antiblocking agents, inhibitors, stabilizers against hydrolysis, ficht, heat and discoloration, flame retardants, dyes, pigments, inorganic and/or organic fillers, for example polycarbonates, and plasticizers and reinforcing agents. Reinforcing agents are, in particular, fibrous reinforcing materials such as, for example, inorganic fibers, which are manufactured using state-of-the-art technology and can also be coated with a size. More detailed information about the auxiliaries and additives mentioned can be found in the specialist literature, for example the monograph by J.H. Saunders and K.C. Fresh "High Polymers", Volume XVI, Polyurethane, Part 1 and 2, Verlag Interscience Publishers 1962 and 1964, the paperback for plastic additives by R. Gächter and H. Müller (Hanser Verlag Munich 1990) or the DE-A 29 01 774.

In a preferred embodiment of the article, the polyurethane binder (B) comprises a polyurethane made from an aliphatic diisocyanate, particularly isophorone diisocyanate or hexamethylene diisocyanate (HDI). The polyurethane is preferably a thermoplastic polyurethane, preferably produced exclusively from aliphatic components, in particular from components as described above. In a particularly preferred embodiment, this polyurethane is obtained by drying a water-based polyurethane dispersion (D).

In a preferred embodiment of the article, the weight ratio of the fibrous web (A) to the polyurethane binder (B) is in the range from 2:1 to 20:1, preferably in the range from 3:1 to 15:1 on the total mass of the item.

In a preferred embodiment of the article, the polyurethane binder (B) has at least one of the following properties:

(Bl) that a film of the binder, formed from a polyurethane dispersion (D), has a breaking stress in a range from 100 kPa to 40 MPa, measured according to DIN EN ISO 527-2:2012-06;

(B2) that a film made from the binder, formed from a polyurethane dispersion (D), has an elasticity in a range from 300% to >2000%, measured according to DIN EN ISO 527-2:2012-06;

(B3) that a film of the binder, formed from a polyurethane dispersion (D), has a Tg of <0° C., preferably <−20° C., particularly preferably <−40° C., determined by means of differential scanning calorimetry based on to DIN EN 61006, method A.;

(B4) that the polyurethane dispersion (D) has a solids content of 30% to 65%, preferably 37% to 63%, based on the total content of the polyurethane binder (B), determined according to DIN EN ISO 3251:2019-09 ;

(B5) that the polyurethane dispersion (D) has a viscosity according to DIN 53019-1-2016-10 (Brookfield method) at 23° C. from 50 mPas to 10000 mPas, preferably 50 mPas to 4000 mPas, particularly preferably <2500 mPas ;

(B6) that the polyurethane binder (B) contains a polyurethane, preferably contains or consists of aliphatic polyurethane.

The polyurethane binder (B) preferably has the combination of properties selected from the group consisting of (B1) and (B2), (B1) and (B3), (B1) and (B4), (B1) and (B5), ( Bl) and (B6), (Bl) and (B7), (B2) and (B3), (B2) and (B4), (B2) and (B5), (B2) and (B6), (B2) and (B7), (B3) and (B4), (B3) and (B5), (B3) and (B6), (B3) and (B7), (B4) and (B5), (B4) and ( B6), (B4) and (B7), (Bl) and (B2) and (B3), (Bl) and (B2) and (B4), (Bl) and (B2) and (B5), B(l ) and (B2) and (B6), B(l) and (B2) and (B7), (Bl) and (B3) and (B4), (Bl) and (B3) and (B5), (Bl) and (B3) and (B6), (Bl) and (B3) and (B7), (Bl) and (B4) and (B5), (Bl) and (B4) and (B6), (Bl) and ( B4) and (B7), (Bl) and (B2) and (B3) and (B4), (Bl) and (B2) and (B3) and (B5), (Bl) and (B2) and (B3) and (B6), (Bl) and (B2) and (B3) and (B7), (Bl) and (B2) and (B4) and (B5), (Bl) and (B2) and (B4) and ( B6), (Bl) and (B2) and (B4) and (B7), (Bl) and (B3) and (B4) and (B5), (Bl) and (B3) and (B4) and (B6) , (Bl) and (B3) and (B4) and (B7), ( B2) and (B3) and (B4) and (B5), (B2) and (B3) and (B4) and (B6), (B2) and (B3) and (B4) and (B7), (B2) and (B4) and (B5) and (B6), (B2) and (B4) and (B5) and (B7), (B2) and (B5) and (B6) and ( B7), (Bl) and (B2) and (B3) and (B4) and (B5), (Bl) and (B2) and (B3) and (B4) and (B6), (Bl) and (B2) and (B3) and (B4) and (B7), (Bl) and (B2) and (B3) and (B5) and (B6), (Bl) and (B2) and (B3) and (B5) and ( B7), (Bl) and (B2) and (B3) and (B6) and (B7), (Bl) and (B2) and (B4) and (B5) and (B6), (Bl) and (B2) and (B4) and (B5) and (B7), (Bl) and (B2) and (B5) and (B6) and (B7), (Bl) and (B3) and (B4) and (B5) and ( B6), (Bl) and (B3) and (B4) and (B5) and (B7), (Bl) and (B3) and (B5) and (B6) and (B7), (Bl) and (B3) and (B4) and (B5) and (B7), (Bl) and (B3) and (B4) and (B6) and (B7), (Bl) and (B4) and (B5) and (B6) and ( B7), (B2) and (B3) and (B4) and (B5) and (B6), (B2) and (B3) and (B4) and (B5) and (B7), (B2) and (B3) and (B5) and (B6) and (B7), (B2) and (B4) and (B5) and (B6) and (B7), (Bl) and (B2) and (B3) and (B4) and ( B5) and (B6), (B1) and (B2) and (B3) and (B4) and (B5) and nd (B7), (Bl) and (B2) and (B3) and (B4) and (B6) and (B7), (Bl) and (B2) and (B3) and (B5) and (B6) and ( B7), (Bl) and (B2) and (B4) and (B5) and (B6) and (B7), (Bl) and (B3) and (B4) and (B5) and (B6) and (B7) , (B2) and (B3) and (B4) and (B5) and (B6) and (B7), (Bl) and (B2) and (B3) and (B4) and (B5) and (B6) and ( B7).

In a preferred embodiment of the article, the polyurethane binder (B) is formed by drying a polyurethane dispersion (D) which is obtainable as a first polyurethane dispersion (D1) by

A) isocyanate-functional prepolymers

Al) organic polyisocyanates, and

A2) polymeric polyols with number-average molecular weights of 400 to 8000 g/mol and OH functionalities of 1.5 to 6, and

A3) optionally hydroxy-functional compounds with molecular weights of 62 to 399 g/mol, and

A4) optionally isocyanate-reactive, anionic or potentially anionic and optionally nonionic hydrophilicizing agents, and

B) their free NCO groups then in whole or in part

Bl) optionally with amino-functional compounds with molecular weights of 32 to 400 g/mol and

B2) are reacted with amino-functional, anionic or potentially anionic hydrophilizing agents with chain extension and the prepolymers are dispersed in water before, during or after step B) to form a first polyurethane dispersion (A), or the polyurethane dispersion (D) as one further polyurethane dispersion (D2) can be obtained by reactively reacting at least the following components: A. an aliphatic polyisocyanate component with an average isocyanate functionality of > 1.8 and < 2.6,

B. a polymeric polyether polyol component;

C. an amino-functional chain extender component with at least 2 isocyanate-reactive amino groups, containing at least one amino-functional compound CI., which has no ionic or ionogenic groups and/or an amino-functional compound C2., which has ionic or ionogenic groups,

D. optionally other hydrophilizing components that are different from C2.,

E. optionally hydroxy-functional compounds with a molecular weight of 62 to 399 mol/g,

F. optionally further polymeric polyols, which are different from B.,

G. a compound that has exactly one isocyanate-reactive group, or a compound that has more than one isocyanate-reactive group, where only one of the isocyanate-reactive groups reacts under the chosen reaction conditions with the isocyanate groups present in the reaction mixture and

H. optionally an aliphatic polyisocyanate component with an average isocyanate functionality of >2.6 and <4, where components B. and F. together contain <30% by weight of component F., based on the total mass of components B. and F. included.

The polyurethane dispersions (A) and (B) differ in their composition at least in the selection or amount of at least one component. Polyurethane dispersions (A) and (B) are consequently chemically different and distinguishable from one another at least in part of the respective polymer.

Preferably, the components of the polyurethane dispersions (A) and (B) and all other components to form the article are low to non-cytotoxic. According to the invention, low to non-cytotoxic means that the foamed article and preferably all 20 components of the article have a vitality of > 70%, preferably > 80%, or a classification from 0 to 2 (“no to mild”, what means little or no cytotoxicity) in a cytotoxic test according to DIN ISO 10993-5:2009-10.

Polyurethane dispersion (A)

In order to achieve anionic hydrophilicization in the preparation of the polyurethane dispersion (A), hydrophilicizing agents are preferably used in A4) and/or B2) which have at least one group which is reactive towards NCO groups, as in the case of A4) amino, hydroxy or thiol groups and, in the case of B2), amino groups and, in addition, -COO- or -SO3- or -PO3 ² as have anionic or their fully or partially protonated acid forms as potentially anionic groups.

Preferred aqueous, anionic polyurethane dispersions (A) have a low level of hydrophilic anionic groups, preferably from 2 to 200 milliequivalents, more preferably from less than 10 to 100 milliequivalents per 100 g of solid resin.

In order to achieve good sedimentation stability, the number-average particle size of the polyurethane dispersions (A) is preferably less than 750 nm, particularly preferably less than 500 nm, determined by laser correlation spectroscopy.

The ratio of NCO groups in the compounds from component A1) to NCO-reactive groups such as amino, hydroxyl or thiol groups in the compounds from components A2) to A4) is from 1.05 to 3.5 in the preparation of the NCO-functional prepolymer ; preferably 1.2 to 3.0 and particularly preferably 1.3 to 2.5.

The amino-functional compounds in stage B) are used in such an amount that the equivalent ratio of isocyanate-reactive amino groups of these compounds to the free isocyanate groups of the prepolymer is 40 to 150%, preferably 50 to 125%, particularly preferably 60 to 100%.

Suitable polyisocyanates of component A1) are the aromatic, araliphatic, aliphatic or cycloabhatic polyisocyanates known per se to those skilled in the art and having an NCO functionality of >2.

Examples of such suitable polyisocyanates are 1,4-butylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 2,2,4- and/or 2,4,4-trimethylhexamethylene diisocyanate, the isomeric bis(4, 4'-isocyanatocyclohexyl)methanes or mixtures of any isomer content, 1,4-cyclohexylene diisocyanate, 1,4-phenylene diisocyanate, 2,4- and/or 2,6-tolylene diisocyanate, 1,5-naphthylene diisocyanate, 2,2'-and /or 2,4'- and/or 4,4'-diphenylmethane diisocyanate, 1,3- and/or 1,4-bis(2-isocyanato-prop-2-yl)benzene (TMXDI), 1,3 -Bis(isocyanatomethyl)benzene (XDI), and alkyl 2,6-diisocyanatohexanoates (lysine diisocyanates) with Cl-C 8 -alkyl groups.

In addition to the polyisocyanates mentioned above, modified diisocyanates with a uretdione, isocyanurate, urethane, allophanate, biuret, iminooxadiazinedione and/or oxadiazinetrione structure and unmodified polyisocyanate with more than 2 NCO groups per molecule, such as 4- Isocyanomethyl-1,8-octane diisocyanate (nonane triisocyanate) or triphenylmethane-4,4',4"-triisocyanate can also be used.

They are preferably polyisocyanates or polyisocyanate mixtures of the type mentioned above with exclusively aliphatically and/or cycloaliphatically bound isocyanate groups and one average NCO functionality of the mixture from 2 to 4, preferably from 2 to 2.6 and particularly preferably from 2 to 2.4.

Particular preference is given in Al) to using 1,6-hexamethylene diisocyanate, isophorone diisocyanate, the isomeric bis(4,4'-isocyanatocyclohexyl)methanes and mixtures thereof.

In A2), polymeric polyols having a number-average molecular weight Mn of from 400 to 8000 g/mol, preferably from 400 to 6000 g/mol and particularly preferably from 600 to 3000 g/mol, are used. These preferably have an OH functionality of from 1.5 to 6, particularly preferably from 1.8 to 3, very particularly preferably from 1.9 to 2.1.

Such polymeric polyols are the polyester polyols, polyacrylate polyols, polyurethane polyols, polycarbonate polyols, polyether polyols, polyester polyols, polyurethane polyacrylate polyols, polyurethane polyester polyols, polyurethane poly ether polyols, polyurethane polycarbonate polyols and polyester polycarbonate polyols known per se in polyurethane coating technology. These can be used in A2) individually or in any mixtures with one another.

Such polyester polyols are the known polycondensates of di- and optionally tri- and tetraols and di- and optionally tri- and tetracarboxylic acids or hydroxycarboxylic acids or lactones. Instead of the free polycarboxylic acids, the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols can also be used to produce the polyester.

It is likewise possible in A2) to use polycarbonates containing hydroxyl groups, preferably polycarbonate diols, with number-average molecular weights Mn of from 400 to 8000 g/mol, preferably from 600 to 3000 g/mol. These can be obtained by reacting carbonic acid derivatives, such as diphenyl carbonate, dimethyl carbonate or phosgene, with polyols, preferably diols.

Instead of or in addition to pure polycarbonate diols, it is also possible to use polyether polycarbonate diols in A2). The polycarbonates containing hydroxyl groups preferably have a linear structure.

Polyether polyols can also be used in A2). For example, the polytetramethylene glycol polyethers known per se in polyurethane chemistry, such as those obtainable by polymerizing tetrahydrofuran by means of cationic ring opening, are suitable.

Likewise suitable polyether polyols are the known addition products of styrene oxide, ethylene oxide, propylene oxide, butylene oxide and/or epichlorohydrin onto di- or polyfunctional starter molecules. Polyether polyols, based on the at least partial addition of ethylene oxide to difunctional or polyfunctional starter molecules, can also be used as component A4) (nonionic hydrophilizing agents).

All compounds known from the prior art can be used as suitable starter molecules, such as water, butyl diglycol, glycerol, diethylene glycol, Trimethylolpropane, Propylene Glycol, Sorbitol, Ethylenediamine, Triethanolamine, 1,4-Butanediol. Preferred starter molecules are water, ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol and butyl diglycol.

Particularly preferred embodiments of the polyurethane dispersions (A) contain a mixture of polycarbonate polyols and polytetramethylene glycol polyols as component A2), the proportion of polycarbonate polyols in the mixture being 0 to 80% by weight and the proportion of polytetramethylene glycol polyols being 100 to 20% by weight. -% amounts to. A proportion of 50 to 100% by weight of polytetramethylene glycol polyols and a proportion of 0 to 50% by weight of polycarbonate polyols is preferred. Particularly preferred is a proportion of 75 to 100% by weight of polytetramethylene glycol polyols and a proportion of 0 to 25% by weight of polycarbonate polyols, each with the proviso that the sum of the weight percentages of the polycarbonate and polytetramethylene glycol polyols is 100% and the proportion the sum of the polycarbonate and polytetramethylene glycol polyether polyols in component A2) is at least 50% by weight, preferably 60% by weight and particularly preferably at least 70% by weight.

The compounds of component A3) have molecular weights of 62 to 400 g/mol.

In A3) polyols of said molecular weight range with up to 20 carbon atoms, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,3-butylene glycol, cyclohexanediol, 1,4 -Cyclohexane dimethanol, 1,6-hexanediol, neopentyl glycol, hydroquinone dihydroxyethyl ether, bisphenol A (2,2-bis(4-hydroxyphenyl)propane), hydrogenated bisphenol A, (2,2-bis(4-hydroxycyclohexyl)propane), trimethylolpropane, glycerin , Pentaerythritol and any mixtures thereof are used with one another.

Also suitable are ester diols in the molecular weight range mentioned, such as α-hydroxybutyl-s-hydroxycaproic acid ester, co-hydroxyhexyl-γ-hydroxybutyric acid ester, β-hydroxyethyl adipate or bis(β-hydroxyethyl) terephthalate.

Furthermore, monofunctional, isocyanate-reactive, hydroxyl-containing compounds can also be used in A3). Examples of such monofunctional compounds are ethanol, n-butanol, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, 2-ethylhexanol, 1-octanol, 1-dodecanol, 1-hexanol . Preferred compounds of component A3) are 1,6-hexanediol. 1,4-butanediol, neopentyl glycol and trimethylolpropane.

Anionically or potentially anionically hydrophilizing compounds of component A4) are understood as meaning all compounds which have at least one isocyanate-reactive group such as a hydroxyl group and at least one functionality such as -COOTVE, -SCETVE, -PO(0 with M ⁺ for example the same as a metal cation, H ⁺ , NH ⁺ , NHR ⁺ , where R can be a C1-C12 alkyl radical, C5-C6 cycloalkyl radical and/or a C2-C4 hydroxyalkyl radical, upon interaction with aqueous media enters into a pH-dependent dissociation equilibrium and can thus be negatively or neutrally charged. Suitable anionically or potentially anionically hydrophilizing compounds are mono- and dihydroxycarboxylic acids, mono- and dihydroxysulfonic acids and mono- and dihydroxyphosphonic acids and their salts. Examples of such anionic or potentially anionic hydrophilizing agents are dimethylolpropionic acid, dimethylolbutyric acid, hydroxypivalic acid, malic acid, citric acid, glycolic acid, lactic acid and the propoxylated adduct of 2-butenediol and NaHSCE, as described in DE-A 2446440, page 5-9, formula I-III is described. Preferred anionic or potentially anionic hydrophilicizing agents of component A4) are those of the type mentioned above which have carboxylate or carboxylic acid groups and/or sulfonate groups.

Particularly preferred anionic or potentially anionic hydrophilizing agents are those which contain carboxylate or carboxylic acid groups as ionic or potentially ionic groups, such as dimethylolpropionic acid, dimethylolbutyric acid and hydroxypivalic acid or their salts.

Examples of suitable nonionic hydrophilizing compounds of component A4) are polyoxyalkylene ethers which contain at least one hydroxy or amino group, preferably at least one hydroxy group.

Examples are the monohydroxy-functional polyalkylene oxide polyether alcohols having a statistical average of 5 to 70, preferably 7 to 55 ethylene oxide units per molecule, as are accessible in a manner known per se by alkoxylating suitable starter molecules (e.g. in Ullmann's Encyclopedia of Industrial Chemistry, 4th edition, Volume 19 , Verlag Chemie, Weinheim p. 31-38).

These are either pure polyethylene oxide ethers or mixed polyalkylene oxide ethers, containing at least 30 mol %, preferably at least 40 mol %, of ethylene oxide units, based on all the alkylene oxide units present.

Preferred polyethylene oxide ethers of the type mentioned above are monofunctional mixed polyalkylene oxide polyethers containing 40 to 100 mol % ethylene oxide units and 0 to 60 mol % propylene oxide units.

Preferred nonionic hydrophilizing compounds of component A4) are those of the type mentioned above, which are block (co)polymers which are prepared by blockwise addition of alkylene oxides onto suitable starters.

Di- or polyamines such as 1,2-ethylenediamine, 1,2- and 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, isophoronediamine, isomer mixtures of 2,2,4- and 2,4,4-trimethylhexamethylenediamine, 2-methylpentamethylenediamine, diethylenetriamine, triaminononane, 1,3- and 1,4-xylylenediamine, a,a,a',a'-tetramethyl-1,3- and -1,4-xylylenediamine and 4,4-diaminodicyclo- hexylmethane and/or dimethylethylenediamine can be used. Also possible, but less preferred, is the use of hydrazine and hydrazides such as adipic acid dihydrazide.

In addition, as component Bl) it is also possible to use compounds which, in addition to a primary amino group, also have secondary amino groups or, in addition to an amino group (primary or secondary), also have OH groups. Furthermore, monofunctional isocyanate-reactive amine compounds can also be used as component B1). Preferred compounds of component Bl) are 1,2-ethylenediamine, 1,4-diaminobutane and isophoronediamine. Mixtures of the aforementioned diamines of component B1) are particularly preferably used, in particular mixtures of 1,2-ethylenediamine and isophoronediamine and mixtures of 1,4-diaminobutane and isophoronediamine.

Anionically or potentially anionically hydrophilizing compounds of component B2) are understood as meaning all compounds which have at least one amino group and at least one functionality such as -COOTVE, -SCETVU, -PO(0 M ) ₂ with M ⁺ , for example, equal to a metal cation , H ⁺ , NH _t ⁺ , NHR3 , where R can each be a C1-C12-alkyl radical, C5-C6-cycloalkyl radical and/or a C2-C4-hydroxyalkyl radical, which enters into a pH-dependent dissociation equilibrium on interaction with aqueous media and can be negatively or neutrally charged in this way. Mixtures of anionic or potentially anionic hydrophilic agents and nonionic hydrophilic agents can also be used for hydrophilic treatment.

In a preferred embodiment for preparing the specific polyurethane dispersions (A), components A1) to A4) and B1) to B2) are used in the following amounts, the individual amounts always adding up to 100% by weight:

5 to 40% by weight component Al),

55 to 90% by weight A2),

0 to 20% by weight sum of components A3) and B1)

0.1 to 25 wt anionic hydrophilizing agents from A4) and/or B2) can be used.

The preparation of the anionically hydrophilized polyurethane dispersions (A) can be carried out in one or more stage(s) in a homogeneous phase or, in the case of a multistage reaction, in some cases in the disperse phase. After all or part of the polyaddition from A1) to A4) has been carried out, a dispersing, emulsifying or dissolving step takes place. This is followed, if appropriate, by a further polyaddition or modification in the disperse phase.

All methods known from the prior art, such as, for example, prepolymer mixing methods, acetone methods or melt dispersing methods, can be used here. is preferred using the acetone method. The method and the components as described in WO 2020/173760 A1 on pages 11 line 27 to page 14 line 12 are preferably used.

The solids content of the polyurethane dispersions (A) is preferably from 35 to 70% by weight, particularly preferably from 40 to 65% by weight, very particularly preferably from 45 to 62% by weight and in particular from 48 to 60% by weight.

The amount of anionic or potentially anionic groups on the particle surface, measured via an acid-base titration, is generally 2 to 500 mmol, preferably 30 to 400 mmol, per 100 grams of solid.

Polyurethane dispersion (B)

In the preparation of the polyurethane dispersion (B), a prepolymer containing isocyanate groups is first formed, which is chain-extended with amino groups. Due to the use of compounds containing amino groups in the preparation of the polyurethane dispersion (B), urea groups can also form, which is why the polyurethane contained in the polyurethane dispersion (B) is also referred to below as polyurethane urea and therefore the polyurethane dispersion (B) is also referred to as polyurethane urea dispersion (B).

In connection with the polyurethaneurea dispersion (B), ionogenic groups are understood as meaning those functional groups which are able, for example by neutralization with a base, to form ionic groups.

Component A. can be any polyisocyanate that one skilled in the art would use for this purpose. Polyisocyanates which are preferably suitable as component A. are in particular the aliphatic polyisocyanates which are known per se to those skilled in the art and have an average isocyanate functionality of >1.8 and <2.6. The term aliphatic also includes cycloaliphatic and/or araliphatic polyisocyanates. The average isocyanate functionality is understood as meaning the average number of isocyanate groups per molecule.

It is preferably a matter of polyisocyanates or polyisocyanate mixtures of the type mentioned above with exclusively aliphatically or cycloaliphatically bound isocyanate groups or mixtures of these and an average NCO functionality of the mixture of >1.8 and <2.6 and particularly preferably >2.0 and < 2.4. The organic polyisocyanate component A particularly preferably contains an aliphatic or cycloaliphatic polyisocyanate selected from HDI, IPDI and/or H12-MDI or their modification products, very particularly preferably selected from HDI and/or IPDI. In a preferred variant, component A. is IPDI and HDI in a mixture.

Particularly suitable as component H. are oligomeric diisocyanates which have a functionality of >2.6 and <4, preferably >2.8 and <3.8, with an isocyanurate, urethane, allophanate, biuret, iminooxadiazinedione or oxadiazinetrione structure . Most preferably, H. isocyanurate structures. The organic polyisocyanate component H. preferably consists of an aliphatic or cycloaliphatic polyisocyanate oligomer based on HDI, IPDI and/or H12-MDI, very particularly preferably based on HDI.

The molar ratio of the NCO groups from component A. to component H. is preferably 100:0.5 to 100:50; more preferably 100:2 to 100:15 and most preferably 100:3 to 100:8.

For the production of the polyurethaneurea used according to the invention, preference is given to using >0 and <10% by weight of component H. and particularly preferably >0.1 and <3% by weight of component H., based in each case on the total mass of the polyurethaneurea.

The polymeric polyether-polyols used according to the invention as component B. preferably have number-average molecular weights of >500 and <8000 g/mol, determined by

Gel permeation chromatography versus polystyrene standard in tetrahydrofuran at 23°C, more preferably >400 and <6000 g/mol and particularly preferably >600 and <3000 g/mol and/or OH functionalities of preferably >1.5 and <6, more preferably >1.8 and <3, particularly preferably >1.9 and <2.1. The term “polymeric” polyether polyols means here in particular that the polyols mentioned have at least three, more preferably at least four, repeat units connected to one another.

In the context of this application, the number-average molecular weight is determined by gel permeation chromatography (GPC) in tetrahydrofuran at 23° C., unless otherwise stated. The procedure is according to DIN 55672-1: "Gel permeation chromatography, part 1 - tetrahydrofuran as eluent" (SECurity GPC system from PSS Polymer Service, flow rate 1.0 ml/min; columns: 2 PSS SDV linear M, 8x300 mm, 5th pm; RID detector). Polystyrene samples of known molar mass are used for calibration. The number-average molecular weight is calculated with the aid of software. Baseline points and evaluation limits are defined according to DIN 55672 Part 1.

Component B preferably contains or consists of poly(tetramethylene glycol) polyether polyols. Suitable poly(tetramethylene glycol) polyether polyols are obtainable, for example, by polymerizing tetrahydrofuran by means of cationic ring opening.

Component B. preferably contains or consists of a mixture of poly(tetramethylene glycol)polyetherpolyols, the poly(tetramethylene glycol)polyetherpolyols differing in their number-average molecular weights.

As component E., polyols, in particular non-polymeric polyols, of the stated molecular weight range of 62 to 399 mol/g with up to 20 carbon atoms, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1 ,4-butanediol, 1,3-butylene glycol,

Cyclohexanediol, 1,4-cyclohexane dimethanol, 1,6-hexanediol, neopentyl glycol, hydroquinone dihydroxy ethyl ether, bisphenol A (2,2-bis(4-hydroxyphenyl)propane), hydrogenated bisphenol A (2,2-bis(4-hydroxycyclohexyl)propane), trimethylolpropane, trimethylolethane, glycerol, pentaerythritol and any mixtures of at least two of which are used. If a polyol is used as component E., this component differs in any case from the polymeric polyether-polyol component B. due to its molecular weight, which is then in any case >400 g/mol for component B.

Further polymeric polyols, which are different from B., can be used as component F. Examples are polymeric polyols that do not fall under the definition of B because they are not polyether polyols - for example the polyester polyols, polyacrylate polyols, polyurethane polyols, polycarbonate polyols, , polyester polyacrylate polyols, polyurethane polyacrylate polyols, polyurethane polyester polyols, , polyurethane polycarbonate polyols and known per se in polyurethane coating technology polyester polycarbonate polyols.

For the production of the polyurethane urea used according to the invention, preference is given to a range of >55 and <90% by weight of the sum of components B. and, if appropriate, F. and particularly preferably in a range of >60 and <85% by weight of the sum of the Components B. and optionally F., each based on the total mass of the polyurethane urea, are used.

Component G. is a compound containing exactly one isocyanate-reactive group, or a compound containing more than one isocyanate-reactive group, with only one of the isocyanate-reactive groups reacting with the isocyanate groups present in the reaction mixture under the reaction conditions selected.

Component G. differs in at least one property from the other isocyanate-reactive groups, in particular component B., which are used to prepare the polyurethane dispersion (B). Component G. preferably differs from the other isocyanate-reactive groups, in particular component B., because of its chemical composition.

The isocyanate-reactive groups of component G. can be any functional group that can react with an isocyanate group, such as hydroxyl groups, thiol groups or primary and secondary amino groups.

In the context of the invention, isocyanate-reactive groups are particularly preferably primary or secondary amino groups which react with isocyanate groups to form urea groups. In addition to the amino group, the compounds of component G. can also contain other principally isocyanate-reactive groups, such as OH groups, in which case only one of the isocyanate-reactive groups reacts with the isocyanate groups present in the reaction mixture under the reaction conditions selected. This can be done, for example, by reacting corresponding amino alcohols at relatively low temperatures, for example at 0 to 60.degree. C., preferably at 20 to 40.degree. Preference is given to working in the absence of catalysts which would catalyze the reaction of isocyanate groups with alcohol groups.

For the production of the polyurethaneurea used according to the invention, preference is given to >0.1 and <20% by weight of component G. and particularly preferably >0.3 and <10% by weight of component G., based in each case on the total mass of the polyurethaneurea, deployed.

Component H. is preferably used and the molar ratio of component G. to component H. is preferably 5:1 to 1:5, particularly preferably 1.5:1 to 1:4 and very particularly preferably 1:1 to 1: 3.

In a preferred embodiment of the article, a film formed from the polyurethane dispersion (D) with a thickness of 100 μm has a 100% modulus of <5 MPa, preferably <3.5 MPa or preferably <2.5 MPa with a simultaneous elongation at break of >300%, preferably >400%, particularly preferably >500%, measured according to DIN EN ISO 527-2:2012-06.

In a preferred embodiment of the article, the polyurethane dispersion (D) has a solids content of polyurethane in a range from 30 to 65% by weight, preferably from 35 to 63% by weight, particularly preferably from 40 to 60% by weight. %, based on the total mass of the dispersion (D).

In a preferred embodiment of the article, the article has at least one, preferably at least two, more preferably at least three, most preferably all of the following properties:

11.) A heat resistance in a range of 50 to 170°C, more preferably in one

range from 60 to 160° C., particularly preferably in a range from 70 to 150° C., determined according to DIN EN 11280:-1: 1998;

12.) A tear strength in a range of 4 N/5cm to 60 N/5cm, more preferably in one

Range from 8 N/5cm to 50 N/5cm, particularly preferably in a range from 10 N/5cm to 40 N/5cm, determined according to DIN EN 29073-3: 1992;

13.) Extensibility in a range from 40% to 200%, more preferably from 60% to 100%, determined according to DIN EN 29073-3: 1992;

14.) An elasticity in a range from 50% to 95%, more preferably from 60% to 90%, based on the length of the article before the elasticity test, determined according to DIN EN 14704-1:2005;

15.) A water absorption capacity in a range from 1 g/g to 7 g/g, more preferably from 2 g/g to 6 g/g, determined according to ISO 9073-12:2005;

16.) A suction rate in a range from 0.04 to 1.3 g/sec, more preferably from 0.05 to 1.2 g/sec, particularly preferably from 0.1 to 1.0 g/sec, determined according to ISO 9073.12:2005; 17.) A rub resistance of at least 6000 rub cycles, preferably at least

8000 rubs, particularly preferably at least 9000 rubs, or preferably in a range from 6000 to 15000 rubs, determined according to DIN EN ISO 12947-1:2007;

18.) A springback performance in a range of 50% to 100%, more preferably in one

Range from 60% to 90%, based on the surface area of the medical device before stretching, measured according to DIN EN 14704-1:2005;

19.) A wash permanence at 60° C. in a range from 5 to 25, preferably in a range from 10 to 20 wash cycles, measured according to DIN ISO 6330:2013;

110.) A water vapor permeability in a range from 0.01 to 0.04 g/m ² x Pa x h, more preferably in a range from 0.02 to 0.03 g/m ² x Pa x h, determined according to EN ISO 15496 :2018;

111.) a vitality of cells of >70%, more preferably >75%, more preferably >80%, or a classification from 0 to 2 in a cytotoxic test according to DIN ISO 10993-5:2009-10;

112.) a thickness in a range from 0.1 to 100 mm, preferably in a range from 0.5 to

50 mm, preferably in a range from 1 to 10 mm;

113.) an IPM value in a range from 0.5 to 5.5, preferably from 0.7 to 3, very particularly preferably <2.5, determined according to DIN EN ISO 9073-10-2005-03;

114.) a basis weight in a range from 25 to 1000 g/m ² , preferably in a range from 50 to 800 g/m ² , more preferably in a range from 100 to 500 g/m ² .

The properties of the item listed under II.) to 114.) can be present in the item in any combination and number.

A method for producing an article, in particular a nonwoven fabric, including the steps:

11.) providing a polymer fiber batt (A);

12.) Providing a polyurethane dispersion (D);

13.) optionally adding additives to the polyurethane dispersion (D);

14.) Contacting the polymer fiber batt (A) with a polyurethane dispersion (D);

15.) Drying of the polyurethane dispersion (D) on the fibrous web (A) as a polyurethane

binder (B) to form the article, particularly the nonwoven fabric.

The provision of the polymer fiber batt (A) can be any type of provision of such a fleece, as would be selected by the person skilled in the art. The provision of the polymer fibrous web (A) is preferably selected from the group consisting of provision on a workbench, an assembly line, a roll, a packaging base or a combination of at least two of these.

The provision of the polyurethane dispersion (D) can be any type of provision of such a dispersion, as the person skilled in the art would select for this purpose. The provision of is preferred Polyurethane dispersion (D) selected from the group consisting of a vessel, a pipe, a trough or a combination of at least two of these.

An additive can be added to the polyurethane dispersion (D) in any way that would be envisaged by a person skilled in the art. The additive is preferably liquid or solid and is preferably added dropwise, poured, trickled or pressed into the polyurethane dispersion (D) with stirring.

The additive is preferably selected from the group consisting of

13.1.) at least one surfactant, such as a foam stabilizer, which is preferably non-cytotoxic;

13.2.) at least one surfactant, which is preferably non-cytotoxic;

13.3.) at least one thickener, preferably an associative PU thickener, which is preferably non-cytotoxic;

13.4.) at least one functional additive to influence the hydrophilic/hydrophobic

Behavior e.g. waxes, silicones, quart. ammonium compounds, salts...

13.5.) at least one additive to improve the rolling behavior;

13.6.) at least one preservative or antibacterial additive, e.g. MIT,

CMIT, BIT, colloidal metal salts or mixtures of at least two thereof;

13.7.) Water.

Commercially available compounds such as fatty acid amides, sulfosuccinamides, hydrocarbon sulfonates, sulfates or fatty acid salts, the lipophilic radical preferably containing 12 to 24 carbon atoms, amphiphilic organosilicone copolymers and alkyl polyglycosides are preferably used as the surface-active substance under 13.1.), the methods known per se to those skilled in the art are obtainable by reacting longer-chain monoalcohols (4 to 22 carbon atoms in the alkyl radical) with mono-, di- or polysaccharides (see, for example, Kirk-Othmer, Encyclopedia of Chemical Technology, John Wiley & Sons, Vol. 24, p. 29) . One of the additives listed under 13.1.) is preferred in an amount of 0.01 to 10% by weight, more preferably in a range from 0.05 to 8% by weight, particularly preferably in a range from 0.1 to 5% by weight, based on the total amount of the polyurethane dispersion (D) used in step 13).

The at least one surfactant under 13.2.) is preferably selected from the group of all known anionic, nonionic and cationic surfactants, anionic and nonionic surfactants are preferred, nonionic surfactants are particularly preferred. Surfactants are substances that reduce the surface tension of a liquid or the interfacial tension between two phases. Certain compounds can thus act both as a surfactant and as a surfactant. One of the additives listed under 13.2.) is preferred in a Amount from 0.01 to 10% by weight, more preferably in a range from 0.05 to 8% by weight, particularly preferably in a range from 0.1 to 5% by weight, based on the total amount of the polyurethane - Dispersion (D) used in step 13.).

Commercially available thickeners such as dextrin, starch, polysaccharide derivatives such as guar gum or cellulose derivatives such as cellulose ether or hydroxyethyl cellulose, organic fully synthetic thickeners based on polyacrylic acids, polyvinylpyrrolidones, poly(meth)acrylic compounds or polyurethanes (associative thickeners) can be used as thickeners 13.3.). inorganic thickeners such as bentonite or silica. Associative polyurethane thickeners are particularly preferably used. The amount of thickener is preferably <5% by weight, or preferably in a range from 0.1 to 5% by weight, more preferably from 0.2 to 2% by weight, based on the total amount of the polyurethane dispersion (D) in step 13.).

The at least one functional additive for influencing the hydrophilic/hydrophobic behavior under 13.4.) is preferably selected from the group of substances influencing the surface tension of a mixture. The same substances are preferably used here as are described under surface-active substances and surfactants. In addition, hydrophobically or hydrophilically modified, soluble polymers can be used. One of the additives listed under 13.4.) is preferred in an amount of 0.01 to 10% by weight, more preferably in a range from 0.05 to 8% by weight, particularly preferably in a range from 0.1 to 5% by weight, based on the total amount of the polyurethane dispersion (D) used in step 13.).

The at least one additive for improving the rolling behavior under 13.5.) is preferably selected from the group consisting of a polyethylene glycol or another associative thickener known in the prior art. One of the additives listed under 13.5.) is preferred in an amount of 0.01 to 10% by weight, more preferably in a range from 0.05 to 8% by weight, particularly preferably in a range from 0.1 to 5% by weight, based on the total amount of the polyurethane dispersion (D) used in step 13.).

It is also possible to add, incorporate or coat the foamed article with antimicrobial or biological active ingredients as component 13.6.), which have a positive effect, for example in relation to wound healing and the avoidance of bacterial contamination. The addition or incorporation with these active ingredients can be done either by adding them to the polyurethane dispersion (D). Preferred active ingredients of the aforementioned type are those from the group of antiseptics, growth factors, protease inhibitors and non-steroidal anti-inflammatory drugs/opiates or active ingredients such as thrombin alfa for local hemostasis. The active ingredient preferably comprises at least one bacteriostatic or a bactericide, very particularly preferably an antiseptic biguanide and/or its salt, preferably the hydrochloride. One of the additives listed under 13.6.) is preferred in an amount of 0.01 to 10% by weight, more preferably in in a range from 0.05 to 8% by weight, particularly preferably in a range from 0.1 to 5% by weight, based on the total amount of the polyurethane dispersion (D) in step 13.).

Several different additives of the additives mentioned under 13.1.), 13.2.), 13.3.), 13.4.), 13.5.), 13.6.), 13.7.) can also be used simultaneously. Preference is given to using at least one, more preferably at least two, very particularly preferably at least three of the additives mentioned under 13.1.), 13.2.), 13.3.), 13.4.), 13.5.), 13.6.), 13.7.).

In step 13.), an additive from each of groups 13.1.) to 13.7.) is preferably added to the polyurethane dispersion (D). Preference is given overall in step 13.) Additive selected from the group 13.1.), 13.2.), 13.3.), 13.4.), 13.5.), 13.6.) or a combination of at least two of these in an amount in a range of 0.01 to 10% by weight, more preferably in a range from 0.05 to 8% by weight, particularly preferably in a range from 0.1 to 5% by weight, based on the total amount of the polyurethane dispersion (D).

The contacting of the polymer fibrous web (A) with the polyurethane dispersion (D) in step 14.) can be any type of contacting that a person skilled in the art would envisage for this purpose. The contacting in step 14.) is preferably selected from the group consisting of dipping, spraying, brushing, printing, coating and pouring or a combination of at least two of these. Contacting preferably takes place by means of spraying. Examples of spraying are airbrush spraying or airless spraying, with airless spraying being preferred. During or after the contacting in step 14.), the polymer fiber web (A) contacted with the polyurethane dispersion (D) can be subjected to pressure. This is preferably done by cold calendering.

The drying of the polyurethane dispersion (D) on the fibrous web (A) as a polyurethane binder (B) to form the article, in particular the nonwoven fabric in step 15.) preferably takes place at a temperature in a range from 50 to 150° C. more preferably from 60 to 120°C, particularly preferably from 70 to 100°C. The drying in step 15.) is preferably carried out over a period of 5 to 120 minutes, more preferably 10 to 100 minutes, particularly preferably 20 to 90 minutes.

In a preferred embodiment of the method, the contacting in step 12.) takes place by means of a method selected from the group consisting of dipping, spraying, brushing, printing, coating, pouring or a combination of at least two of these.

Examples of spraying are the overspray method, the rotary spray method. An example of dipping is the pad-batch process. Example of coating is direct coating or air squeegee. Foam coating is an example of casting. These methods are well known to those skilled in the art from the prior art. The article produced in this way preferably has all the properties, compositions, shapes and sizes as previously described for the article according to the invention. The article according to the invention and the article produced according to the method according to the invention are particularly suitable for the medical field of application as a single-use or multiple-use article. In particular for multiple use of the article, the article should be able to be washed and sterilized several times, ie it should be able to withstand both detergents and temperatures of up to 150° C., in particular under increased pressure. When used as a medical article, the article goes through the following steps in particular: a. Use as a medical article, such as gowns, sheets, surgical clothing; b. washing the item; c. sterilizing the item; i.e. Feel free to reuse the item. step a..

Another object of the invention relates to the use of the article according to the invention or the article produced according to the method according to the invention as a wound dressing, a hygiene article, a disposable medical article or multiple articles, preferably selected from the group consisting of disposable or multiple clothing, a disposable medical bed sheet or multiple bed sheets, a surgical cover, surgical clothing, in particular a surgical gown, a fleece compress, a padded bandage, a cast bandage, a post-surgical bandage, an absorbent compress, a wound seam strip, a zinc paste bandage, a carrier for hydrotherapy, a carrier for antiseptics , a foam bandage, a support for decubitus orthoses or a combination of at least two of these. For use, the article is placed as for its conventional use, as described above in relation to the article of the invention.

experimental part

Methods:

The stated viscosities were determined by means of rotational viscometry in accordance with DIN 53019-1-2016-10 at 23° C. using a rotational viscometer from Anton Paar Germany GmbH, Ostfildern, DE (1 Pas=1 N/m ² *s).

The solids content was determined in accordance with DIN EN ISO 3251:2019-09 by heating a weighed sample at 105 °C to constant weight. At constant weight, the solids content was calculated by weighing the sample again.

The glass transition temperature T _g was determined by means of differential scanning calorimetry (DSC) based on DIN EN 61006-2004-11, method A, using a DSC device (calorimeter Pyris Diamond DSC from Perkin-Elmer) that was used to determine T _g was calibrated with indium and lead. 10 mg of the substance to be examined were placed in a lockable aluminum Crucible weighed and sealed. Three consecutive runs of heating from -100°C to +150°C, heating rate 20 K/min, followed by cooling at a cooling rate of 320 K/min were carried out and the third heating curve was used to determine the values. The temperature at half the height of a glass transition stage was determined as T _g .

Determination of the water vapor permeability, also MVTR (Moisture vapor transmission rate)

The MVTR was determined based on DIN EN 13726-2-2002-06 (Part 3.2). A metal cylinder was filled with water, as described in the DIN, and closed at the top by the film or layer to be examined. The total weight (beaker with water and film) was then determined using a balance. The measurement setup was stored for 24 hours at 37°C and the weight was again determined. The water loss that evaporates through the film could be determined by subtraction. The MVTR is given in g/(m ² *24 h).

The following experiments are exemplary methods for making chemically bonded nonwoven materials. They should not be interpreted restrictively but should be given as an example.

The chemical bonding was preferably carried out on carded or airlaid nonwoven materials, ie nonwoven materials in which the fibers experience an initial orientation or alignment, during carding by contact with an aid in the airlaid process by means of fuft, all possible fiber orientation.

All experiments were carried out on non-bonded fibrous webs of different compositions, so that the effectiveness of chemical bonding can be demonstrated in a fiber- and function-specific manner.

In the case of non-consolidated fibrous web materials, the test materials show a significant increase in strength values in the longitudinal and transverse directions of at least 4-5 times the strength values according to DIN EN 29073-3: 1992 after the inventive consolidation with the polyurethane binder. This ensured a stability typical of use.

In all experiments, the test material was therefore in the form of an unconsolidated fibrous web and was treated and chemically consolidated using the formulations and processes listed. Comparative tests were carried out on the chemically bonded nonwoven fabrics produced by the experiments.

The unconsolidated fibrous webs were produced on a standard laboratory scale (up to 10 kg per batch) or in pilot plants (up to 100 kg per batch). They could be described by typical properties known to those skilled in the art, such as pile weight, initial thickness, MD/CD orientation, etc.

Experiment 1 (overspray / spray method)

Description of unconsolidated batt material (A)-l: Fiber web, corresponding to polymer fiber web (A)-1, consisting of 100% viscose and a web weight of 70 g/m ² and an initial thickness of about 11.2 mm was provided. The fibrous web (A)-1 had no dimensional orientation of the fibers since it was produced using the airlaid process.

Formulations of the polyurethane dispersion used (D)-l: 5 to 99.65% by weight of polyurethane dispersion in the form of ^Baymedix® FD 103 or ^Baymedix® AD 111 or ^Baymedix® CD 102 from Covestro Deutschland AG, Leverkusen an additive 13.) in an amount of 0.35% by weight of a nonionic surfactant: octyl glucoside 65% by weight or hexyl glucoside 75% by weight, each based on the solids content, each in water, from Sigma-Aldrich, Germany , and X% by weight of water (drinking water quality, max. 12 °dH), where X can be calculated in such a way that the sum of the components used is 100 parts, depending on how much polyurethane dispersion was used, so that a 100 wt.

Table 1: Formulation compositions tested, adding 0.35 wt% octyl glucoside (65 wt% in water) for all trials to always get 100 wt%:

Production of the polyurethane dispersion (D)-1 used for experiments VI to V15 from Table 1:

The formulation components for experiments VI to V15 mentioned above, in particular in connection with Table 1, were mixed at 23° C. in the order mentioned above. Mixing was carried out using an agitator from IKA-Werke GmbH & Co. KG and the associated propeller stirring rod at 80 rpm and for a stirring time of 2 minutes.

Application of the polyurethane dispersion (D)-l:

The application of the particular polyurethane dispersion (D)-1, in the amounts indicated in Table 1 for VI to V15, was carried out on the unconsolidated polymer fiber web (A)-1, as described above on a screen belt with a feed rate of 25 m/min using the airless spray method. The spray nozzle of the spray device used, of the type W590 FlexiO from J. Wagner GmbH, was positioned centrally above the sieve belt and delivered an application volume of 500 ml/min.

Drying and fixation:

The polymer fiber web (A)-1, sprayed with the polyurethane dispersion as described above, was dried without tension on a pin frame in a FABDRYER FTE convection drying oven from Mathis AG, CH-8156 Oberhasli. Drying was carried out at 80° C. for 30 seconds and then the polyurethane binder (B)-1 was fixed for 90 seconds at 140° C. in the same commercially available oven.

Test result on test material experiment 1:

With the linting test, the IPM value of the article is determined according to the parameters according to DIN EN ISO 9073-10-2005-03, the results of which are shown in Figure 1. The lower the IPM value, the lower the detachment of individual fibers, also known as fluff, from the nonwoven composite, which occurs when a fibrous web (A) is consolidated using a binder. This was previously described for a polymer fibrous web (A) with different polyurethane dispersions (D) (VI-V15) to form a polyurethane binder (B) to form an article according to the invention. The goal was to keep the IPM value as low as possible. It can be seen that even when using 5% by weight of a polyurethane dispersion (diluted with 95% by weight of water), in this case polyurethane dispersion 3 containing Baymedix® CD102 from experiment V15, an IPM value of less than 1.5 could be achieved. A satisfactory IPM value of less than 6 according to EN ISO 9073-10-2005-03 was achieved for all of the polyurethane dispersions (D) 1, 2 and 3 according to the invention which were used as binders. In some cases it was possible to achieve significantly lower values of <2.8 for 10% by weight of polyurethane in the polyurethane dispersion (D) or even of <1 for 100% by weight of polyurethane in the polyurethane dispersion (D). Individual values of the tests can be seen in FIG. If 50% by weight of polyurethane dispersion is used for the total formulation, an excellent IPM value of less than 2 is even achieved for all of the polyurethane binders (B).

Experiment 2 (foam method)

Description of unconsolidated batt material (A)-2:

A fibrous web (A)-2 consisting of 100% by weight viscose and a web weight of 70 g/m ² and an initial thickness of about 11.2 mm was provided. The fibrous web (A)-2 had no dimensional orientation of the fibers and served as a preliminary product of an airlaid nonwoven.

Formulations of the polyurethane dispersion used (D)-2: In 5 tests, 5/10/30/50/ ^99.65 ^wt . - % non-ionic surfactant alkyl polyglucoside from Sigma-Aldrich, Germany, and X wt. results, depending on how much polymer dispersion was used, resulting in a 100 parts by weight total formulation as polyurethane dispersion (D)-2.

Production of a polyurethane foam from the polyurethane dispersion (D)-2:

The polyurethane dispersion (D)-2 with a density or foam liter weight of 100 g/l was foamed. Mixing and frothing took place using a kitchen hand mixer in a graduated 3 L plastic beaker. For this purpose, 200 g of the total formulation of the polyurethane dispersion (D)-2 were weighed out and foamed at high speed until the 2L mark was reached.

Application of the solidification liquor:

The polyurethane dispersion (D)-2 prepared as a foam was applied directly to the unconsolidated fibrous web (A)-2 by means of a doctor blade method. The sample was fixed on a pin clamping frame. The foam from the polyurethane dispersion (D)-2 was applied using the air knife method. The squeegee setting was −3 mm and, with this setting, produced a wet laydown of the total formulation of 50 g/m ² .

Drying and fixation:

The polymer fiber batt (A)-2, which was treated with the polyurethane dispersion (D)-2 provided as a foam as described above, was tension-free on the pin frame in the LABDRYER LTE convection drying oven from Mathis AG, CH-8156 Oberhasli dried. Drying was carried out at 80° C. for 30 seconds and then the polyurethane binder (B)-2 was fixed for 90 seconds at 140° C. in the same commercially available oven.

Experiment 3 (foam method)

Description of unconsolidated batt material (A)-3:

A fiber web (A)-3 consisting of 100% viscose and a web weight of 70 g/m ² and an initial thickness of about 11.2 mm was provided. The fibrous web (A)-3 had no dimensional orientation of the fibers and served as a preliminary product of an airlaid nonwoven.

Formulations of the polyurethane dispersion (D)-3 used as solidification liquors:

In 5 tests, 5 / 10 / 30 / 50 / 99.65% by weight polymer binder Baymedix ^® FD 103 or AD 111 or CD 102

0.35% by weight nonionic surfactant alkyl polyglucoside 0.30% by weight thickener Rheolate 208 from Elementis UK ltd. and

X% by weight of water (drinking water quality, max. 12°dH) is used, where X can be calculated in such a way that the sum of the components used is 100% by weight.

Production of the solidification liquors used:

The formulation components mentioned were mixed at 23 °C in the above order and foamed to 100 g/l. Mixing and frothing took place using a cake hand mixer in a graduated 3 L plastic beaker. For this purpose, 200 g of the total formulation were weighed out and foamed at high speed until the 2L mark was reached.

Application of the solidification liquors:

The setting paste was applied directly to the non-set fibrous web using a doctor blade method. The sample was fixed on a pin clamping frame. The paste was applied using the foot squeegee method. The squeegee setting was - 3mm and at this setting produced a wet application of the total formulation of 50 g/m ²

Drying and fixation:

Tension-free on a pin frame in a circulating air drying oven: drying for 30 seconds at 80 °C and fixing for 90 seconds at 140 °C

Experiment 4 (overspray, spraying method)

Description of the unconsolidated batt material (pre-oriented web):

Fibrous web consisting of 100% by weight viscose, a web weight of 90 g/m ² and an initial thickness of about 17.8 mm was presented. The batt had a dimensional orientation of the fibers and served as a precursor to a carded nonwoven fabric with an MD/CD orientation ratio of 2.4.

Recipes of the solidification liquors used:

⁴⁶ ^wt .

0.35% by weight nonionic surfactant: octyl glucoside 65% or hexyl glucoside 75% (in dry matter)

53.65% by weight of water (drinking water quality, max. 12° dH) were used to make up 100% by weight of the total formulation.

Production of the solidification liquors used:

The formulation components mentioned were mixed at 23 °C in the above order. Mixing was carried out using a stirrer and associated propeller stirrer at 80 rpm and for a stirring time of 2 minutes.

Application of the solidification liquors: The bonding liquor was applied to the non-bonded fiber web on a screen belt with a feed rate of 25 m/min using the airless spray method. The spray nozzle of the spray device used, of the type W590 FlexiO from J. Wagner GmbH, was positioned centrally above the sieve belt and delivered an application volume of 500 ml/min.

Drying and fixation:

Tension-free on a pin frame in a circulating air drying oven: drying for 30 seconds at 80 °C and fixing for 90 seconds at 140 °C.

Test result on test material experiment 4:

The strength of the article, in particular of the nonwoven fabric, was determined using the DIN EN ISO 9073-4-1997-09 method. Results for this are shown in FIG. It can be seen that the non-inventive example ^Plextol® DV 245 has significantly lower tensile strengths than the inventive examples at all binder concentrations.

Test result on test material experiment 4:

The absorbency of the nonwoven could be determined using the DIN EN ISO 9073-12:2002 method. Results for this are shown in FIG. The absorbency was determined according to the DIN EN ISO 9073-12:2002 standard. Even when using 100 parts (% by weight) of Baymedix® ^FD103 or Baymedix® ^AD111 , it was still possible to demonstrate sufficiently high absorbency of the fleece.

Test result on test material experiment 3:

FIG. 4 shows the characteristics of the binder sags, which are a measure of the strength of the nonwoven fabric consolidation. A behavior of the non-woven fabric is referred to as binder sail, in which the non-woven fabric/fiber web of the non-woven fabric is stably crosslinked/linked via attachment points to the individual fibers. The area of the truss sail is an indication of whether the largest possible embedding and fixation of the individual fibers can be achieved, taking into account a structure that is as voluminous as possible. The higher the area of the sails, the better the degree of consolidation of a voluminous fleece material. As shown in FIG. 4, high area values could be achieved for all examples according to the invention.

Test result on test material experiment 4:

The fabric touch tester (FTT) was used to determine the deformability of the article, particularly of the nonwoven fabric. The FTT is a device that measures a textile's grip and the wearing comfort of a textile by determining physical parameters that allow conclusions to be drawn about the wearing comfort. Results for this are shown in FIG. The parameters given in FIG. 5 were measured according to the AATTC 216/217 standard, which is currently in the approval phase. Here, too, it could be shown that the binder Baymedix ^® AD111 according to the invention both in the impact absorption rate, as well as in the recovery rate and the Compression rate in [%] higher and thus better values than the comparative example ^Plextol® DV 245, which was used in the same amount by weight, namely 46% by weight, as described in Experiment 4.

Claims

Patent Claims:

1. An article, preferably a fibrous structure, particularly preferably a nonwoven fabric, containing at least one polymer fibrous web (A) and at least one polyurethane binder (B), wherein at least part of the polymer fibrous web (A) is separated from the polyurethane binder ( B) is surrounded or in contact with it.

2. The article of claim 1 wherein the polymer batt (A) is selected from the group consisting of a natural polymer or a synthetic polymer or a combination thereof.

3. The article according to any one of the preceding claims, wherein the polymer batt (A) is selected from the group consisting of a natural polymer, in particular from the group consisting of cellulose, cotton, hemp fiber, bamboo fiber, flax fiber, wool fiber and viscose fiber or one Mixture of at least two of these.

4. The article according to any one of the preceding claims, wherein the polymer fiber web (A) is selected from the group consisting of a synthetic polymer, in particular from the group consisting of polyurethane (PU), polyester, preferably a polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), polypropylene (PP), polyamide (PA), polyethylene (PE), vinyl acetate, aramid fibers and acrylate or a mixture of at least two of these.

5. The article according to any one of the preceding claims, wherein at least part of the polyurethane binder (B) is in contact with at least 50%, preferably with at least 70%, particularly preferably with at least 90% of the fibers of the polymer fiber batt (A). .

6. The article according to any one of the preceding claims, wherein the polymer batt (A) has at least one of the following properties:

(Al) Heat resistance in a range from +50 °C to +400 °C, determined according to DIN EN 11280-1:2998;

(A2) consists of fibers which have a fineness in a range from 0.6 dtex to 2.4 dtex, measured according to DIN EN ISO 1973:1995;

(A4) consists of fibers having a face to face ratio of from 1:1 to 1:10;

7. The article according to any one of the preceding claims, wherein the weight ratio of the fibrous web (A) to the polyurethane binder (B) is in a range from 2: 1 to 20: 1, preferably in a range from 3: 1 to 15 :1 based on the total weight of the item.

8. The article according to any one of the preceding claims, wherein the polyurethane binder (B) has at least one of the following properties:

(Bl) A film of the binder, formed from a polyurethane dispersion (D), has a breaking stress in a range from 100 kPa to 40 MPa, measured according to DIN EN ISO 527-2:2012-06;

(B2) A film of the binder, formed from a polyurethane dispersion (D), has an elasticity in a range from 300% to >2000%, measured according to DIN EN ISO 527-2:2012-06;

(B3) A film of the binder formed from a polyurethane dispersion (D), a Tg of <60°C, preferably <50°C, more preferably in a range from 20 to 60°C;

(B4) has a solids content of 30% to 65%, based on the total content of the polyurethane binder (B), determined in accordance with DIN EN ISO 3251:2019-09;

(B5) a viscosity according to DIN 53019-1-2016-10 at 23° C. from 50 mPas to 10000 mPas, preferably from 50 mPas to 4000 mPas, particularly preferably <2500 mPas;

(B6) includes a polyurethane, preferably includes or consists of aliphatic polyurethane;

(B7) has a Tg < - 40 °C, determined by means of differential scanning calorimetry based on DIN EN 61006, method A.

9. The article according to any one of the preceding claims, wherein the polyurethane binder (B) is formed by drying a polyurethane dispersion (D) which is obtainable as a first polyurethane dispersion (D1) by

A) isocyanate-functional prepolymers

Al) organic polyisocyanates

A2) polymeric polyols with number-average molecular weights of 400 to 8000 g/mol and OH functionalities of 1.5 to 6 and

A3) optionally hydroxy-functional compounds with molecular weights of 62 to 399 g/mol and

B) their free NCO groups then in whole or in part Bl) optionally with amino-functional compounds with molecular weights of 32 to 400 g/mol and

B2) are reacted with amino-functional, anionic or potentially anionic hydrophilizing agents with chain extension and the prepolymers are dispersed in water before, during or after step B), or where the polyurethane dispersion (D) is obtainable as a further polyurethane dispersion (D2). by reactive conversion of at least the following components:

A. an aliphatic polyisocyanate component with an average isocyanate functionality of > 1.8 and < 2.6,

B. a polymeric polyether polyol component;

D. optionally other hydrophilizing components that are different from C2.,

F. optionally further polymeric polyols, which are different from B.,

H. optionally an aliphatic polyisocyanate component with an average isocyanate functionality of >2.6 and <4, where components B. and F. together make up <30% by weight of component F., based on the total mass of components B. and F. included.

10. The article according to the preceding claim, wherein a film formed from the polyurethane dispersion (D) with a thickness of 100 μm has a 100% modulus of <5 MPa, preferably <3.5 MPa or preferably <2.5 MPa simultaneous elongation at break of >500%, preferably >1000%, particularly preferably >1500%.

11. The article according to one of the two preceding claims, wherein the polyurethane dispersion (D) has a solids content of polyurethane of 30 to 65% by weight, based on the total mass of the dispersion (D).

12. The article of claim 1, wherein the article has at least one of the following properties:

11.) A heat resistance in a range from +50 °C to + 170 °C, determined by

DIN EN 11280:-1: 1998;

12.) A tear strength in a range from 4 N/5cm to 60 N/5cm, determined according to DIN

EN29073-3:1992;

13.) An extensibility in a range of 40% to 200%, based on the size of the

Article before the stretching process, determined according to DIN EN 29073-3:1992;

14.) An elasticity in a range of 50% to 95% based on the size of the

Article before the elasticity test, determined according to DIN EN 14704-1:2005;

15.) A water absorption capacity in a range from 1 g/g to 7 g/g determined by

ISO 9073-12:2005;

16.) A suction speed in a range from 0.04 to 1.3 g/sec, determined according to ISO

9073.12:2005;

17.) A rub resistance of at least 6,000 rub cycles, or preferably in a range from 6,000 to 15,000 rub cycles, determined according to DIN EN ISO 12947-1:2007;

18.) A springback behavior in a range of 50% to 100%, based on the

Surface expansion of the medical article before stretching, measured according to DIN EN 14704-1:2005;

19.) A wash permanence at 60 °C in a range of 5 to 25 wash cycles, measured according to DIN ISO 6330:2013;

110.) A water vapor permeability in a range from 0.01 to 0.04 g/m ² x Pa xh, determined according to EN ISO 15496:2018;

111.) a vitality of cells of >_70% or a classification from 0 to 2 in one

Cytotox test according to DIN ISO 10993-5:2009-10;

112.) a thickness in a range of 0.1 to 100 mm.

13. A method for producing an article, in particular a nonwoven fabric, comprising the steps:

11.) providing a polymer fiber batt (A);

12.) Providing a polyurethane dispersion (D);

13.) optional addition of additives to the polyurethane dispersion (D)

14.) Contacting the polymer fiber batt (A) with a polyurethane dispersion (D);

15.) Drying of the polyurethane dispersion (D) on the fibrous web (A) as the polyurethane binder (B) to form the article, in particular the nonwoven fabric.

14. The method according to the preceding claim, wherein the contacting in step 12.) takes place by means of a method selected from the group consisting of dipping, spraying, brushing, coating, pouring or a combination of at least two of these.

15. A use of the article according to one of claims 1 to 11 or 14 or produced according to one of claims 12 or 13 as a wound dressing, a hygiene article, a disposable medical article or multiple articles, preferably selected from the group consisting of a disposable or multiple clothing, a medical disposable bed sheet or multiple bed sheets, a surgical cover, surgical clothing, in particular a surgical gown, a fleece compress, a padded bandage, a cast bandage, a post-surgical bandage, an absorbent compress, a wound seam strip, a zinc paste bandage, a carrier for

hydrotherapy, an antiseptic carrier, a foam dressing, a decubitus orthosis carrier or a combination of at least two of these.