WO2023094586A1

WO2023094586A1 - Fibre material having an antimicrobial and odour-neutralising effect

Info

Publication number: WO2023094586A1
Application number: PCT/EP2022/083266
Authority: WO
Inventors: Ayad Abul-Ella; Olaf Wagner; Carsten Meyer; Uwe Landau; Frank Meister; Marcus Krieg; Christoph KINDLER
Original assignee: Agxx Intellectual Property Holding Gmbh
Priority date: 2021-11-25
Filing date: 2022-11-25
Publication date: 2023-06-01
Also published as: EP4187004A1

Abstract

The invention relates to a fibre material having an antimicrobial effect, comprising fibres of regenerated cellulose and/or regenerated cellulose derivatives and also at least one antimicrobial active agent component. The invention also relates to a method for producing a fibre material having an antimicrobial effect, a fibre material produced by this method, and the use of the fibre material. The active agent component of the fibre material according to the invention comprises silver (Ag) and ruthenium (Ru), with silver and ruthenium being in electrical contact with one another and embedded in the cellulose - and/or cellulose derivative - fibres and/or at least partially surrounded thereby. The fibre material according to the invention has not only antimicrobial properties, but advantageously also deodorising and/or odour-neutralising properties. In particular, the durability of the efficacy of the sanitary fibres according to the invention is surprising. After 50 washes and even after 100 washes, no considerable deterioration in the efficacy or reduction of the antimicrobial, deodorising and/or odour-neutralising properties can be observed.

Description

Fiber material with antimicrobial and odor-neutralizing effect

Background of the Invention

The invention relates to a fiber material with an antimicrobial effect, which comprises fibers made from regenerated cellulose and/or regenerated cellulose derivatives and at least one antimicrobial active ingredient component. The invention also relates to a method for producing a fiber material with an antimicrobial effect, a fiber material produced by this method and the use of the fiber material.

State of the art

Antimicrobial fibers, fiber composites, yarns and textile fabrics are known. Numerous publications such as DE 10 2006 056977 B3, DE 10 2007 019 768 A1 and DE 10 2008 045 290 A1 describe additives made from antimicrobial, particulate, liquid or meltable or vaporizable active substances or active substance compounds from metallic nano- or microphases, Salts, glasses or modified aluminosilicates or organic biocide active ingredients for wet, dry-wet or dry-spun fibers. These additives are added before or during the shaping process or to finish fibers, yarns or textiles (e.g. EP 0 677 989 B1). The disadvantageous, common feature of such functionalized fibers, fiber composites, games and fabrics is the insufficient resistance and the resulting worsening or even non-existent effect, which is difficult for the user to control, e.g. due to washing out of the active ingredients that are decisive for the function.

In addition to the textile, paper and building materials industries, cellulose is also used in medicine. The widespread use of cellulose materials, in particular their use for medical applications, has led to the development of cellulose fibers with an antimicrobial finish. The majority of work on the production of antimicrobial cellulose has so far involved the introduction of biocidal nano-silver particles on or into the Cellulose fibers employed by various deposition processes (e.g. US Pat. No. 8,367,089 B2 and DE 603 05 172 T2).

Antimicrobial fibers or textiles that contain coatings or active ingredients or active ingredient compounds, such as combinations of silver, copper or zinc ions, which are fixed in or on the fiber matrix, e.g. on ion exchange resins, in glasses or modified aluminosilicates better resistance to washing out, but the effectiveness deteriorates after just 10-20 wash cycles, since these technologies are based uniformly on the release of the respective active ingredient (depot effect). Because of this depot effect, higher active ingredient concentrations of significantly more than 1% by weight would be necessary for a longer persistence of the effect. This is opposed by the fact that the antimicrobial agents mentioned above, such as silver, copper, zinc, etc., because of the risk they impede the cellulose modification (viscose or carbamate process) or the spontaneous, autocatalytic decomposition of the solvent used ( Lyocell process), which is reflected in an exothermic DSC curve by a significant reduction in the temperature for the start of decomposition of the preferably used N-methylmorpholine-N-oxide (NMMO) ("on-set temperature") of approx. 160°C sometimes below 130°C, can only be introduced into the fiber matrix in a very small amount (« 1%) during the shaping step (solution production and fiber spinning). Also disadvantageous, especially with active substance concentrations of several percent by weight, as you would need for a constant effectiveness of conventional active substances, is the impairment of the fiber properties such as mechanical stability, long life, dyeability, water absorption/absorbency and processability.

In summary, it can be said that to date there are no fibers, fiber composites, games and textile fabrics that can be produced using standard processes and equipment, have fiber properties that are comparable to those of untreated fibers and have a lasting effect over the entire textile life cycle have an antimicrobial effect. Summary of the Invention

It is an object of the present invention to provide a fiber material with an antimicrobial effect that lasts over the entire life cycle, which can be produced using standard processes and equipment and has properties that are comparable to those of untreated fiber materials.

The object is achieved according to the invention by a fiber material of the type mentioned in which the active ingredient component comprises silver (Ag) and ruthenium (Ru), silver and ruthenium being in electrical contact with one another and in the cellulose and/or cellulose derivative fibers are embedded and / or at least partially surrounded by them. The fiber material according to the invention comprises regenerated fibers which not only have antimicrobial properties but, surprisingly, also have deodorizing and/or odor-neutralizing properties. These properties of the fiber material according to the invention (hereinafter also referred to as “hygiene fibers”) are not based on the release of heavy metal ions or organic biocide active ingredients, but surprisingly still show an antimicrobial effectiveness that clearly exceeds the values required in the relevant standards. In addition, the fiber materials according to the invention also have a deodorizing and/or odor-neutralizing effect, which is not only due to the inhibition or killing of microorganisms, but also advantageously to a neutralization (e.g. by degradation or conversion) of organic substances (odorous substances or - molecules) based. The persistence of the effectiveness of the hygiene fibers according to the invention is particularly surprising. No significant deterioration in the effectiveness or reduction in the antimicrobial, deodorizing and/or odor-neutralizing properties can be observed either after 50 washes or after 100 washes. It is also surprising for the person skilled in the art that the antimicrobial, deodorizing and/or odor-neutralizing properties of the fiber material according to the invention do not depend on the presence or accessibility of the active ingredient component on the surface of the hygiene fibers, but despite the presence in the fiber cross-section of the cellulose - and/or cellulose derivative - fibers introduced active ingredient component with complete and wash-out resistant inclusion in the fiber matrix are fully pronounced. A particular advantage of the fiber material according to the invention is that it has properties that are comparable to those of untreated fiber materials, for example with regard to mechanical stability, lifespan, dyeability, water absorption/absorbency and processability.

According to the invention, the active substance component comprises silver (Ag) and ruthenium (Ru), silver and ruthenium being in electrical contact with one another. Silver and ruthenium can be at least partly in metallic form, at least partly in the form of their salts and/or at least partly in the form of a metal compound. Silver and ruthenium have different electrochemical potentials and thus form a galvanic cell (ie a "microgalvanic cell"). If this cell is short-circuited via an aqueous phase, a high electric field strength is created due to the small distance (nm or pm range) between the two metals that are in contact. This contributes significantly to killing germs. Redox reactions take place on both electrodes of the microgalvanic element, each of which leads to the killing of microorganisms. At the first half element (cathode), molecular oxygen is reduced to oxygen radicals, which then have a toxic effect on the microorganisms. At the second half-element (anode), electrons are given off by the microorganisms to the silver semiconductor and this is destroyed by oxidation. The active ingredient component of silver and ruthenium according to the invention, whose antimicrobial effectiveness is not based on the release of biocides or metal ions, but on the catalytically supported generation of oxygen radicals, does not change its composition even with long-term use and, in contrast to biocides or oligodynamic metals, does not require a depot or devices that regulate biocide or metal ion release. In contrast to biocides and oligodynamic metals, which have to release toxic substances into the environment in order to be effective, when the active ingredient component according to the invention is used only water is formed from the oxygen radicals formed. Since the metal combination Ag/Ru is a catalytically supported system, its antimicrobial effect advantageously depends exclusively on the active surface and not, as in the case of biocides or the oligodynamic systems (silver, copper and zinc or their salts or compounds), on their quantity and leaching rate.

The two metals (silver and ruthenium) can be applied, for example, as a layer system on the surface of a particulate carrier (carrier material), the layer of one metal lying at least partially over that of the other metal. The respective upper layer can be porous (particularly nanoporous) or microcracked, particularly cluster-shaped, applied to or deposited on the other metal, so that the aqueous solution or moisture has access to both half-cells and the microgalvanic element is short-circuited . Alternatively or additionally, however, the two metals (half elements) can also be applied in the form of individual particles to the surface of a particulate carrier (carrier material). In principle, it can be, for example, bimetal particles that include both metals and/or metal particles that each include only one of the two metals. The latter can be applied sequentially, i.e. first particles of the first metal and then particles of the second metal (or vice versa), or simultaneously as a mixture of particles of both metals onto a carrier material in such a way that they are in electrically conductive contact. The particles can be applied to the carrier material in a single layer (lying next to one another) and/or at least partially in multiple layers (lying on top of one another).

In an advantageous embodiment of the invention, it is provided that silver and ruthenium are at least partially embedded in particulate form and homogeneously distributed in the cellulose and/or cellulose derivative fibers and/or are at least partially surrounded by them. The homogeneous distribution of individual particles within the fibers or in the fiber cross section ensures a uniform antimicrobial, deodorizing and/or odor-neutralizing effect of the active component within and on the entire surface of the fibers.

In a further advantageous embodiment of the invention, it is provided that silver and ruthenium are at least partially in the form of silver/ruthenium bimetallic particles present. The silver/ruthenium bimetallic particles can, for example, comprise silver particles which are partially coated with ruthenium. Additionally or alternatively, the silver/ruthenium bimetallic particles may comprise particles of cellulose and/or cellulose derivatives coated with silver and ruthenium.

In a further advantageous embodiment of the invention it is provided that the silver and Zor the ruthenium is present at least partially in the form of a metal compound, the metal compound comprising at least one metal oxide, metal oxyhydrate, metal hydroxide, metal oxyhydroxide, metal halide and Zor at least one metal sulfide. The present invention thus advantageously also includes, for example, an active ingredient component which is a semiconducting, catalytically active ruthenium compound (half element I of a galvanic element) and a semiconducting, sparingly soluble silver compound (e.g. silver oxide, silver hydroxide, silver sulfide, silver halogen -Compounds or combinations thereof; half-element II of the galvanic element). Ruthenium is a noble metal that has several oxidation states and, due to its different valences, is able to form different ruthenium oxides, for example. Surface redox transitions such as Ru(VIII)ZRu(VI), Ru(VI)ZRu(IV), Ru(IV)ZRu(III) and possibly Ru(III)ZRu(II) are responsible for the high catalytic activity of ruthenium mixed compounds and their good electrical conductivity. The unusually pronounced catalytic and electrocatalytic properties of the ruthenium compounds depend on the variation of the oxidation states. The antimicrobial effect is, for example, particularly high in the case of active substance components according to the invention which comprise ruthenium(VI) oxide in the first half element. The high catalytic activity of such half-elements for the reduction of oxygen can be attributed to the easy change in the oxidation state and the easy exchange of oxygen, which preferably take place at the active centers of the semiconductor surface. The ruthenium is only changed in terms of its value, which causes the actual redox reaction to occur. Therefore, no ruthenium compound is consumed or formed, only the oxidation states are changed. The ruthenium compound binds the molecular oxygen, allowing it to be catalytically reduced. That's why this is Presence of several valences a prerequisite for the catalytic effect and the redox reaction. So no ruthenium compound has to be formed. Poorly soluble silver compounds have catalytic properties, electrical conductivity and high stability in water. The active ingredient component can, for example, in addition to metallic ruthenium and metallic silver, also contain a semiconducting, catalytically active ruthenium oxide or ruthenium sulfide (half element I of the galvanic element) and a semiconducting, poorly soluble silver compound (silver oxide, silver hydroxide, silver sulfide, silver-halogen compounds or combinations thereof; half-element II of the galvanic element).

The fiber material according to the invention can be used, for example, in the form of antimicrobial fibers as a component of fiber composites, yarns and/or textile fabrics (hygiene fiber composites, hygiene yarns or textile hygiene fabrics), so that they have antimicrobial, deodorizing and odor-neutralizing properties that last over their entire textile life cycle. The fiber material according to the invention can, for example, also be used for the production of absorbent fabrics, which in turn can be used as wound dressings, wound dressings and/or plaster materials and/or can be integrated into them.

The object is achieved according to the invention by a method for producing a fiber material with an antimicrobial effect, in particular the fiber material described above, which comprises the following steps: a) providing pulp comprising cellulose and/or cellulose derivatives, b) optionally producing a Solvent system comprising at least one solvent and water, c) mixing the pulp with at least one solvent and water, or optionally with the solvent system according to b) to produce a pulp, d) dissolving the cellulose and/or cellulose derivatives in the pulp for the production of a spinning solution; e) pressing the spinning solution through spinnerets and f) regenerating the cellulose and/or cellulose derivatives to produce modified cellulose and/or cellulose derivative fibers, wherein at least one antimicrobial agent component comprising silver (Ag) and ruthenium (Ru) is added to the pulp and/or the dope and/or optionally to the solvent system.

According to the invention, the antimicrobial active ingredient component is therefore added during fiber production, for example in the lyocell, viscose or carbamate process. The effect of this is that the active substance component or silver and ruthenium can be completely embedded in the fibers and/or is at least partially surrounded or entwined by them. In this context, it was found, even for those skilled in the art, that the addition of the silver-ruthenium active ingredient component did not result in a lowering of the on-set temperature or other disadvantageous impairments of the production process. In this way, the fiber production could be carried out on the standard systems and with the standard processes without any loss of quality, even with the addition of this active ingredient component. It is also surprising for the person skilled in the art that the antimicrobial, deodorizing and/or odor-neutralizing effect of the fiber material produced according to the invention, which is produced, for example, using the dry-wet spinning process and is already provided with particulate, liquid or meltable or vaporizable active ingredient components during the shaping process, not based on the release of heavy metal ions or organic biocide active substances and nevertheless shows an antimicrobial effectiveness that clearly exceeds the values required in the relevant standards. Furthermore, the persistence of the effectiveness of the fiber material produced according to the invention is surprising for the person skilled in the art. No appreciable deterioration in effectiveness can be observed either after 50 washes or after 100 washes. For example, fiber materials according to the invention still show a high level of effectiveness in the antibacterial test based on DIN EN ISO 20743:2013 ( absorption method) both against the gram-positive test germ Staphylococcus aureus and against the gram-negative test germ Klebsiella pneunomiae and in the antiviral test based on ISO 18184 (test virus: phi 6 DSM 21518, host bacterium: Pseudomonas sp. DSM 21482) still achieves full antiviral efficacy within 2 hours.

It is also surprising for the person skilled in the art that no superficial coating of the cellulose - and/or cellulose derivative - fibers is required in order to produce the antimicrobial, deodorizing and/or odor-neutralizing effectiveness of the fiber material according to the invention. In contrast to the prior art, the active ingredient component introduced into the fiber cross-section of the fibers is fully effective, even on the fiber surface, even if it is completely, homogeneously and scavenge-resistantly included in the fiber matrix. A particular advantage of the fiber material produced according to the method according to the invention is that it has properties that are comparable to those of untreated fiber materials, e.g. in terms of mechanical stability, durability, dyeability, water absorption/absorbency and processability.

In an advantageous embodiment of the method according to the invention, it is provided that the antimicrobial active component is added in solid form, in particular as a powder, and dispersed in the pulp and/or the spinning solution and/or optionally the solvent system.

In an advantageous embodiment of the method according to the invention, it is further provided that the antimicrobial active ingredient component in solid form, in particular as a powder, is first dispersed in the solvent system and the dispersion produced in this way is then added to the pulp.

In a further advantageous embodiment of the method according to the invention, it is provided that the pulp is homogenized after the addition of the antimicrobial active ingredient component.

In a further advantageous embodiment of the method according to the invention, it is provided that silver and ruthenium are added at least partially in the form of silver metal particles which are partially coated with metallic ruthenium. In a further advantageous embodiment of the method according to the invention it is provided that silver and ruthenium are added at least partially in the form of particles which comprise a carrier material on which silver and ruthenium are applied. The carrier material is preferably selected in such a way that it also dissolves or at least separates from the silver and ruthenium under the conditions required in step d) for dissolving the cellulose and/or cellulose derivatives. In particular, the carrier material can comprise cellulose and/or at least one cellulose derivative. For example, an antimicrobial fiber material can advantageously be produced using the method according to the invention with such a cellulose-silver-ruthenium particle variant of the active component using lyocell technology, since the cellulose-silver-ruthenium particles, despite their catalytic activity, have no negative have an influence on the decomposition temperature (on-set temperature) of the solvent N-methylmorpholine-N-oxide (NMMO) used in the lyocell process and can therefore be processed in the lyocell process. In the lyocell process, the carrier material cellulose dissolves in the NMMO and releases the silver-ruthenium particles deposited on the carrier material in the cellulose-containing solvent, evenly distributed, so that antimicrobial regenerated lyocell fibers for the textile industry, but also for nonwovens (non- wovens) and other technical applications such as foils, e.g. B. for packaging can be produced.

These particles are not nanoparticles but rather particles that have a length, diameter and/or circumference greater than 100 nanometers (nm).

The carrier material can, for example, comprise at least one material selected from the group consisting of cellulose, glass, zeolite, silicate, metal or a metal alloy, metal oxide (eg TiO2), ceramic, graphite and a polymer. The active ingredient component can thus be adjusted in a targeted manner by the choice of the carrier material with regard to the integration requirements in the cellulose and/or cellulose derivative fibers of the specific application. For example in relation to water absorption/absorbency (e.g. cellulose as a carrier material) for production applications in apparatus from which particle removal is only possible from outside with a magnet (magnetic particles such as iron particles as carrier material), cellulose integration in the production of regenerated fibers, in which the cellulose doped with the active ingredient component according to the invention is in the organic cellulose solution dissolves and the active component is finely distributed in the pulp, from which cellulose threads can then be spun, or the color design (e.g. white color: cellulose as the carrier material).

Surprisingly, with regard to the process according to the invention, a new possibility of producing antimicrobial regenerated fibers has resulted from the selection of cellulose as the carrier material for silver and ruthenium. For example, cellulose (C) or its derivatives can be used as a carrier material as microcrystalline (MCC) or nanocrystalline cellulose powder (NCC), which have a number of inherent properties that support the antimicrobial, deodorizing and/or odor-neutralizing effect of the fiber material according to the invention. such as B. their hydrophilicity and a high water-binding capacity, which is still about 5-8% in the dry state. The regenerated fibers produced according to the invention can be varied not only in fiber length but also in fiber cross-section, as a result of which the fiber surface can be increased considerably. In addition to the “standard cellulose” with a cloud-shaped cross section, fibers with star (Trilobal) or letter-like (Umberto) cross sections are also available. The cellulose carrier surface can also be significantly enlarged by so-called bacterial cellulose (BC) due to its tissue-like, fine network structure. BC also has an increased water absorption capacity and is therefore often used in medical applications.

In addition to silver and ruthenium, the active ingredient component can also include other substances that have surface-active effects (e.g. surfactants), lipophilic properties (e.g. oils or fats) and/or hydrophilic properties (e.g. silicate particles). In a further advantageous embodiment of the method according to the invention, it is provided that the solvent is N-methylmorpholine-N-oxide (NMMO), which is frequently used in the production of regenerated fibers. Alternatively, other suitable solvents or solvent systems, such as N,N-dimethylbenzylamine-N-oxide or sodium hydroxide/carbon disulfide (NaOH/CS2), or solvents from the group of ionic liquids, such as 3-butyl-1-methylimidazolium acetate, can also be used ([BMIM]Ac), used as a solvent for the cellulose or cellulose derivatives in the manufacturing process.

The object is also achieved according to the invention by a fiber material that was produced by means of the method described above. This fiber material according to the invention is characterized by an antimicrobial, deodorizing and/or odor-neutralizing effect that lasts over its entire service life and has other properties that are comparable to those of untreated fiber materials, e.g are.

The object is also achieved according to the invention by using the fiber material according to the invention for the production of wound dressings, wound dressings and/or plaster materials. Game, knitted fabric, crocheted fabric and/or woven fabric produced from the fiber material according to the invention can therefore be used advantageously for the production of wound dressings, wound dressings and/or plaster material due to the properties mentioned. These yarns, knitted fabrics, crocheted fabrics and/or woven fabrics can themselves be used as a wound dressing, wound dressing and/or plaster material and/or be integrated into such a dressing material in the form of at least one absorbent body, for example in close connection with a carrier material. The games, knitted fabrics, crocheted fabrics and/or woven fabrics produced from the fiber material according to the invention form an absorbent material which absorbs the wound exudate, including the germs located in the wound. Thus, the spread of germs in the absorbent material absorbing the exudate and a return transfer of the germs absorbed with the exudate into the wound be prevented. Due to the fact that the absorbent material according to the invention absorbs, immobilizes and inactivates or kills the microorganisms or germs discharged from the wound with the wound secretion, a correspondingly designed or equipped wound dressing material can exert a significant antimicrobial effect without the antimicrobial substances/substances or Mechanisms must be present and/or operative at the surface of the covered wound. Thus, wound dressings, wound dressings and/or plaster materials equipped with and/or consisting of the fiber material according to the invention can advantageously develop an effective antimicrobial effect even if the wound or wound surface does not come into contact with antimicrobial materials or substances. Therefore, the wound dressings, wound dressings and/or plaster materials comprising the fiber material according to the invention contribute in a particularly advantageous manner to the gentle and well-tolerated acceleration of wound healing due to their integrated antimicrobial effect and the avoidance of reinfection. An absorbent material comprising the fiber material according to the invention can, for example, also be the carrier of a substance and/or material which maintains a moist climate in/over the wound, e.g. a hydrogel.

The invention further encompasses the use of an antimicrobial active ingredient component comprising metallic silver (Ag) and metallic ruthenium (Ru) as an agent for reducing or preventing odors in textile fiber materials. Fibers doped with this antimicrobial active ingredient component and fiber composites, yarns and textile fabrics made from them not only have an antimicrobial effect that lasts over the entire life cycle of the textile structures, but also surprisingly and advantageously have a deodorizing and/or odor-neutralizing effect. It turned out that this additional effect is not solely due to the inhibition or killing of microorganisms, but is also based in particular on a neutralization (eg through degradation or conversion) of organic substances. In olfactometric studies on the decay behavior of odor contamination (set-up: test on the long-lasting effects of odors and scents), it was demonstrated that typical organic compounds that cause bad or foul odors, such as iso- Valeric acid (3-methylbutanoic acid) or 3-hydroxy-3-methylhexanoic acid on fiber materials that were doped with the antimicrobial active component according to the invention could no longer be detected after a uniform loading time of 180 minutes after 60 minutes. Other organic substances that can be responsible for bad smells from textile fiber materials are, for example, 3-methyl-2-hexenoic acid, thioalcohol, androstenone, butyric acid, n-valeric acid, n-hexanoic acid and n-octanoic acid. These and many other odorous substances can also be neutralized effectively and over the entire textile life cycle by using the antimicrobial Ag/Ru active substance component according to the invention.

Because of the properties mentioned, games, knitted fabrics, crocheted fabrics or fabrics made from the fiber material according to the invention are outstandingly suitable as sports, leisure or outdoor textiles, as home textiles and as medical textiles for wound care or healing. Woven or nonwoven fabrics made from the fiber material according to the invention can also be used, for example, as permanently antimicrobial cleaning cloths (e.g. in the kitchen), plastic-coated nonwoven pieces in dishwashers or to support the washing effect in the washing machine. The invention also relates to hygiene fiber composites made from them, hygiene yarns and textile hygiene fabrics and textiles made up from them.

Hygienic threads can be mixed as part of the secondary spinning process from 1 to 99% of the fiber material according to the invention with many mixed fibers used in textiles (natural and chemical fibers such as cotton, linen, hemp, wool, viscose, modal, lyocell, polyester, polyacrylonitrile, polyamide, polypropylene ) form. Hygiene fibers and/or hygiene yarns made from them can also be processed into fabrics with an active ingredient content of 0.05 to 90% using the usual textile fabric formation processes (including nonwoven fabric manufacture). In a particular embodiment, games, fabrics or textiles can also be subsequently coated with the antimicrobial active component in one of the processing processes mentioned or special finishing steps. In addition to a simple coating by means of active ingredient dispersions and subsequent active ingredient fixation, for example by drying, a coating is also possible with the aid of special techniques such as ultrasonic impregnation or the like.

"Regenerated fibers" in the sense of the invention refers to man-made fibers made from regenerated cellulose and/or cellulose derivatives, which are produced from cellulose (pulp is a fibrous mass produced during the chemical digestion of plant fibers, which mainly consists of cellulose or cellulose derivatives (wood)) by means of a chemical process become. Examples of regenerated fibers are viscose, modal, lyocell and cupro.

“Antimicrobial effect” within the meaning of the invention refers to the property of a substance, a combination of substances, a material, material composite and/or a surface of the same to kill microorganisms, to inhibit their growth and/or to prevent or impede microbial colonization or attachment.

“Microorganisms” within the meaning of the invention refers to unicellular or few-celled, microscopically small organisms or particles that are selected from the group consisting of bacteria, fungi, algae, protozoa and viruses.

"Pulp" in the sense of the invention refers to a cellulose dispersion dissolved down to the individual fibers in an aqueous solution.

“Particles”, “particulate” or “particulate” within the meaning of the invention designates individual particulate bodies which as a whole are delimited from other particles and their surroundings. All possible particle shapes and sizes, regardless of geometry and mass, are included within the scope of the invention.

"Half-element" in the sense of the invention refers to a part of a galvanic element that forms this in conjunction with at least one other half-element. A half-element comprises a metal electrode, which is at least partially in an electrolyte. "Galvanic cell", "galvanic element" or "microgalvanic element" in the sense of the invention refers to the combination of two different metals, each of which forms an electrode (anode or cathode) in a common electrolyte. If the two metal electrodes are in direct contact with each other or if they are electrically conductively connected to one another via an electron conductor, the less noble metal with the lower redox potential (electron donor, anode) gives electrons to the more noble metal with the higher redox potential (electron acceptor, cathode) and sets in Follow the redox processes at the electrodes.

“Electrolyte” within the meaning of the invention denotes a substance (e.g. ions in an aqueous solution) which, under the influence of an electric field, conducts electric current through the directed movement of ions.

"Metal" within the meaning of the invention refers to atoms of a chemical element of the periodic table of elements (all elements that are not non-metals), which form a metal lattice by means of metallic bonds and thus a macroscopically homogeneous material, which is characterized, among other things, by high electrical conductivity and a high thermal conductivity. The term "metal" within the meaning of the invention also includes alloys that include at least two different metals, metals that are present at least partially in the form of their respective salts, and metal compounds such as metal oxides, metal oxyhydrates, metal hydroxides, metal oxyhydroxides, metal halides and metal sulfides, and combinations of metals and corresponding metal compounds.

The invention is explained in more detail below with reference to the following figures and examples.

Brief description of the illustrations

FIG. 1 shows a photograph of the antimicrobial effectiveness of a cellulose thread produced by means of a lyocell process: zone of inhibition test for the effectiveness of the thread material produced according to the invention against E. coli (DSM 498). FIG. 2 shows a bar chart of the antibacterial effectiveness of a cellulose thread produced by means of a lyocell process: effect of a particulate cellulose-based silver-ruthenium hybrid against Staphylococcus aureus (DSM 799).

K = Control (Tula Organic Cotton, 100%)

425-01 = Fleece made from Lyocell fibers with 1% cellulose silver/ruthenium particles after 50 washes

FIG. 3 shows a bar chart of the antibacterial effectiveness of a cellulose thread produced by means of a lyocell process: effect of a particulate cellulose-based silver-ruthenium hybrid against Klebsiella pneumoniae (DSM 789).

K = Control (Tula Organic Cotton, 100%)

FIG. 4 shows a bar chart of the antiviral effectiveness of a cellulose thread produced by means of a lyocell process: effect of a particulate cellulose-based silver-ruthenium hybrid against bacteriophage phi6 (DSM 21518).

K = control (polyester fleece F5)

426-01 = Lyocell fibers without modification, 100%

426-02 = Fleece made from Lyocell fibers with 1% cellulose silver/ruthenium particles after 50 washes

FIG. 5 shows a bar chart of the antibacterial effectiveness of a cellulose thread produced by means of a lyocell process: effect of a particulate cellulose-based silver-ruthenium hybrid against Staphylococcus aureus (DSM 799).

K = Control (Tula Organic Cotton, 100%)

434-01 = blank, washed

434-02 = Fleece made from Lyocell fibers with 1% cellulose silver/ruthenium particles after 100 washes

434-03 = fleece made of pure cellulose, 100% FIG. 6 shows a bar chart of the antibacterial effectiveness of a cellulose thread produced by means of a lyocell process: effect of a particulate cellulose-based silver-ruthenium hybrid against Klebsiella pneumoniae (DSM 789).

K = control (polyester fleece F5)

435-01 = blank, washed

435-02 = Fleece made from Lyocell fibers with 1% cellulose silver/ruthenium particles after 100 washes

435-03 = fleece made of pure cellulose, 100%

FIG. 7 shows a bar chart of the antiviral effectiveness of a cellulose thread produced by means of a lyocell process: effect of a particulate cellulose-based silver-ruthenium hybrid against bacteriophage phi6 (DSM 21518).

K = Control (Tula Organic Cotton, 100%)

434-01 = blank, washed

434-03 = fleece made of pure cellulose, 100%

Figure 8 shows a bar chart of an analytical odor test on the suitability of textiles for reducing sweat odor, which was carried out by Hohenstein Laboratories, Bönnigheim:

Internal control: sweat odor simulation without textile

Sample No. 18.8.4.0126-1: Silver and ruthenium coated polyester fiber fleece

Sample No. 18.8.4.0126-2: polyester fiber fleece (reference)

Description of exemplary and preferred embodiments of the invention

FIG. 1 shows the antimicrobial effectiveness of an antimicrobial cellulose thread produced via the lyocell process, which has been produced by adding a cellulose-based silver/ruthenium active ingredient component to the lyocell process, against E. coli (DSM 498) using the the inhibition zone developed around the thin thread. FIGS. 2 to 7 show the significant antimicrobial effect of cellulose Ag/Ru threads produced by means of a Lyocell process against Staphylococcus aureus (DSM 799), Klebsiella pneumoniae (DSM 789) and bacteriophage phi6 (DSM 21518). The cellulose filaments were produced by adding only 1% of a particulate cellulose-based silver-ruthenium hybrid to a cellulose dope. The test material with an active ingredient content of 1% Ag/Ru was spun with a target titre of 1.7 dtex. 10 g/l Afilan RA was used as finish. To determine the textile-physical values, staple fibers with a length of 40 mm were cut by hand. 10 mm short-cut fibers were used for the washing tests and the production of wet webs on the sheet former. The 50 or 100 washing tests were carried out based on the DIN EN ISO 6330 test standard. For this purpose, the fiber samples were individually portioned into nylon stockings. As an additional load, a washing machine was filled with sheets made of 100% cotton to a total of 2 kg. 18 g of washing powder were used for each wash. The washing program "easy care short" (69 min, 1,200 rpm, water consumption 50 l/h) was selected. To investigate the antimicrobial effectiveness, wet webs were produced from the opened short-cut fibers using a laboratory sheet former. The target mass per unit area of the wet web was 250 g/m ² A fiber mixture with a mixing ratio of 30% Ag/Ru fiber and 70% pure cellulose fiber was used for the wet web. To clarify the influence of the washes, unmodified cellulose fibers were washed and evaluated in addition to a control (PET) and high-purity cotton (Tula organic cotton) with regard to the antimicrobial effect.

After 0, 50 and 100 washes, the manufactured wet nonwovens with an Ag/Ru functional fiber content of 30% received the following rating for the tested test germs:

- Staphylococcus aureus - gram positive; strong effective

- Klebsiella pneunomiae - gram negative; strong effective

In the test based on ISO 18184, full antiviral effectiveness was determined after 2 hours.

Neither unmodified cellulose fibers washed in parallel, a PET control nor an organic cotton also washed in parallel show an antibacterial effect or an antiviral effect. This shows that the antimicrobial effect found in the tested cellulose Ag/Ru fabrics is based on the incorporation of silver (Ag) and ruthenium (Ru) in the modified fibers. The numerical changes in the absolute values can be regarded as being within the range of variation of the test method used.

FIG. 3 shows the result of an analytical odor test on polyester fibers. A defined quantity of Hohenstein sweat simulation ng 114 was applied to textile die-cuts, incubated in an odor bag for 60 minutes at 37°C and finally the odor intensity was assessed by odor testers in accordance with VDI 3882 using an olfactory sampler. It can be seen here that under the test conditions for the polyester fiber fleece coated with silver and ruthenium, a reduction in the intensity of sweat odor of 0.7 intensity points was determined compared to the reference. The odor intensity of the reference was rated strong to very strong by the odor testers, while the odor intensity of the Ag/Ru nonwoven fabric was rated clear to strong. The Ag/Ru active ingredient component thus causes a significant reduction in odor intensity in polyester fibers. It is to be expected (and still to be proven) that the odor reduction through the use according to the invention of the Ag/Ru active ingredient component in fiber materials made of cellulose and/or cellulose derivatives is even more pronounced in comparison with a corresponding reference material. This expectation is based on the fact that plastic fibers absorb odor molecules less well than e.g. B. cotton or cellulose. For example, polyester fabrics release odor molecules faster or more easily (i.e. in greater numbers) than cotton. From this fact it can be concluded that the odor molecules are held inside cotton or cellulose fibers so that they can be effectively neutralized by an embedded antimicrobial component comprising silver (Ag) and ruthenium (Ru). .

Example 1 (Comparative example 1)

399 g of cellulose (type MODO, DP: 590, solids content: 95.5%) are mixed with 3,486 g of 80% aqueous NMMO solution in a stirred tank made of stainless steel. 2.4 g of propyl gallate (0.63% based on the Pulp dry weight) was added and everything was thoroughly mixed together for 15 minutes using an Ultra-Turrax at 10,000 ^rpm . The mixture is then transferred to a double-walled stirred vessel and the excess water is distilled off with stirring at 95° C. and a vacuum of 20 mbar. The resulting cellulose solution, whose onset temperature (temperature of the start of decomposition of the solvent NMMO), which was determined for example according to [Knorr 2006] using a mini-autoclave as a time-dependent change in pressure (dp/dT) _max . 153 °C, is manually transferred to a storage vessel and degassed at 80 °C.

The spinning solution prepared in this way is extruded with a gear spinning pump through nozzle holes with a diameter of 90 μm under weak N2 pressure and the resulting spinning capillaries are distorted in the air gap, regenerated when passing the spinning bath surface and exhaustively freed from NMMO with the spinning bath conducted in countercurrent.

After drying at 60° C., the fibers cut into staple fibers with a staple length of 38 mm have a final fineness (according to DIN EN ISO 1973 1995-12) of 1.62 dtex. Its tenacity (according to DIN EN ISO 5079 1996-2) is 43.60 cN/tex, its elongation (also determined according to DIN EN ISO 5079:1996-2) is 12.8% and its loop tearing strength (according to DIN 53843-2). :1988-03) was determined to be 15.10 cN/tex.

The antibacterial effect (based on DIN EN ISO 20743:2013 absorption method, cf. Examples 4-6) both against gram-positive (Staphylococcus aureus) and against gram-negative (Klebsiella pneumoniae) test strains was determined to be ineffective in each case. The determination of the antiviral effectiveness (based on ISO 18184, test virus: phi6) also showed no reduction in the viral load over a determination time of 2 hours.

(A. Knorr: "Application of TRAS 410 to the safety assessment of a perester synthesis", dissertation TU Berlin, 2006, p. 34 ff)

Example 2 (Comparative Example 2)

In a stainless steel container, 36 g of a finely ground ion exchange resin (weakly crosslinked cation exchanger based on a crosslinked copolymer of acrylic acid and sodium acrylate with a grain size D90 8 μm) is dissolved in 1 l of aqueous NMMO (60%, w/w) using an Ultra-Turrax high-performance disperser. homogeneously distributed and after a standing time of 30 Minutes of a pulp of 377 g pulp (MoDo, DP: 590, solids content: 95.5%) and 3,372 g NMMO are added. The modified pulp is homogenized again for 15 minutes at 10,000 ^rpm . In addition, 2.4 g of gallic acid are added to the pulp as a stabilizer, and the mixture is transferred to a double-walled stirred tank. Its onset temperature was 145 °C. The excess water is removed with stirring at 100° C. and a vacuum of 25 mbar until the cellulose is homogeneously dissolved. After transfer of the spinning solution prepared in this way, staple fibers with a length of 60 mm, a linear density of 6.7 dtex, a tensile strength of 25.7 cN/tex, a maximum elongation of 14 8% and a loop tensile strength related to the fineness of 8.2 cN/tex. The staple fibers, which have been completely freed from the solvent but are still initially moist, are loaded with a 0.1 molar silver nitrate solution per kilogram of staple fiber material, pressed and then washed once with a sodium chloride solution.

Finally, the loaded staple fibers are dried at 80 °C until they reach equilibrium moisture content. The silver content of the fibers manufactured in this way is around 6 percent.

Example 3 (Comparative Example 3)

A cellulose pulp produced analogously to Example 1 is a homogeneous mixture of 36 g of a ZnO / ZnS mixture (1: 2, w / w, each D99 2 pm) and 0.5 I 60% NMMO (w / w) and 0.63% (based on the amount of cellulose used) gallic acid propyl ester added. The mixture is homogenized at ^10,000 min

1.5 dtex, a breaking strength related to the tenacity of 35.4 cN/tex, an elongation at break of 14.2% and a breaking strength related to loops of 9.8 cN/tex. The zinc content is 9%.

Example 4 (silver/ruthenium functional fibers)

3.6 g silver/ruthenium powder is finely distributed in 0.5 l aqueous NMMO (60%, w/w) using a Turrax high-performance dispersing device. The dispersion is then a pulp of 377 g of cellulose (analogous to Example 2) and 3872 g of NMMO added and all together again homogenized at 10,000 min ^-1 for 15 minutes. Gallic acid propyl ester was used as a stabilizer in a concentration of 0.63% (based on the cellulose used). The thermal stability of the spinning solution prepared analogously to Example 1 is determined by means of onset temperature measurement and at 150° C. shows a value that is unobjectionable from a safety point of view. The fibers spun and aftertreated analogously to Example 1 have a final fineness of 1.76 dtex, a breaking strength of 42 cN/tex, an elongation at break of 13.6% and a tightness of loops of 14.4 cN/tex and are therefore the fibers Example 1 completely equivalent.

Example 5 Antimicrobial Efficacy of Non-Functionalized Samples The antibacterial efficacy (based on DIN EN ISO 20743:2013 absorption method) was determined both against gram-positive (Staphylococcus aureus) and against gram-negative (Klebsiella pneumoniae) test strains. It was calculated as the difference between the Ig reduction of a control tested in parallel (Tula cotton) and the Ig reduction of a short fiber fleece sample over 24 hours in each case. Values above 3 are considered to have a strong antibacterial effect.

To determine the antiviral effectiveness (based on ISO 18184, test virus: phi6), the reduction in the viral load of a parallel tested reference (usually PET) and a sample was recorded over 2 hours. It is calculated from the difference in the logarithms of the mean phage titers of the reference and the sample after 2 hours of contact.

A fiber sample produced according to example 1 proved to be antibacterial against neither gram-positive nor gram-negative test germs. The investigation also revealed no reduction in viral load over a 2-hour determination time. Even after 50 or 100 wash cycles, these samples showed no or only very low, non-specific antibacterial and no antiviral activities, which can result from the very smooth fiber morphology (cf. Table 1). Example 6 (Antimicrobial Efficacy of Fibers Finished with Silver or Zinc)

The lyocell fibers, which had been spun analogously to Example 2 or Example 3, were processed into staple fiber yarns and subsequently into blended fabrics with a total functional fiber content of approx. 30%. Representative pieces of tissue were subjected to the antibacterial and antiviral studies referred to in Example 6. Unwashed mixed fabrics showed an Ig reduction Alog of 4.0 (Example 2) or 3.4 (Example 3) against Staphylococcus aureus and 3.8 (Example) or 3.1 (Example 3) against Klebsiella pneumoniae. The reduction in viral load after 2 hours was 3.1 (Example 2) and 3.0 (Example 3), respectively. After 30 washes based on DIN EN ISO 6330, the antibacterial Ig reduction Alog compared to Staphylococcus areus was 2.9 (Example 2) or 2.0 (Example 3) and compared to Klebsiella pneumoniae to 2.4 (Example 2) or 1.8 (Example 3) dropped. The reduction in viral load at 2 hours declined into the low antiviral potency for both samples, and was 2.4 (Example 2) and 2.1 (Example 3). Based on the values obtained, no larger number of wash cycles was examined.

Example 7 (Antimicrobial Efficacy of Silver/Ruthenium Finished Fibers)

Fibers produced analogously to example 1 and example 4 were cut into short staple fibers with staple lengths <5 mm before the fibers were dried. The staple fibers, dried to equilibrium moisture content, were processed with the aid of a Rapid-Kothen type sheet former to form circular wet fleece pieces with a dry weight of about 150 g/m ² . To determine their antimicrobial effect, both completely unmodified and short-fiber nonwovens made of 70% pure lyocell fibers (manufactured according to example 1) and 30% fibers with 1% silver/ruthenium additive (manufactured according to example 4) were used. Similar to Example 4, the test germs mentioned there were also tested here. Unmodified fibers were tested as a reference after 0 and 100 washes, and 70/30 short fiber batts as a sample after 0, 50 and 100 washes. The washing tests of all wet nonwovens were carried out based on DIN EN ISO 6330. The washed webs were after the end of the washing tests each opened separately, redispersed in deionized water and placed back into the short-fiber fleece using the Rapid Köthen sheet former.

Table 1 shows the results of the independently performed antimicrobial studies.

Table 1: Reduction in the test germ concentration after the stated number of washes

• antibacterial effectiveness, Alog = (Ig

** Antiviral potency, M _v = Ig V _R - Ig V _c , where V _R = mean logarithm of phage titers after 2 h contact with the reference sample

V _c = mean logarithm of phage titers after 2 h exposure to antiviral sample

Alog > 3 = highly effective; 3 > Alog > 2 = significantly effective; 2 > Alog > 0.5 = slightly active, Alog < 0.5 not active M _v > 3 = full antiviral activity; 3.0 > M _v > 2.0 = low antiviral efficacy

- - not determined; SA = Staphylococcus aureus (gram positive); KP = Klebsiella pneumoniae (gram negative), Phi 6 = phi 6 DSM 21518 (bacteriophage)

Claims

26

Claims Fibrous material with an antimicrobial effect, which comprises fibers made from regenerated cellulose and/or regenerated cellulose derivatives and at least one antimicrobial active ingredient component, characterized in that the active ingredient component comprises silver (Ag) and ruthenium (Ru), silver and ruthenium being in electrical contact with one another are and in the cellulose - and / or cellulose derivative - fibers are embedded and / or at least partially surrounded by them. Fibrous material according to claim 1, characterized in that silver and ruthenium are at least partly homogeneously distributed in particulate form in the cellulose and/or cellulose derivative fibers embedded and/or at least partly surrounded by them. Fibrous material according to Claim 1 or 2, characterized in that silver and ruthenium are present at least partially in the form of silver-Zruthenium bimetallic particles. Fibrous material according to Claim 3, characterized in that the silver/ruthenium bimetallic particles comprise particles of cellulose and/or cellulose derivatives which are coated with silver and ruthenium. Fibrous material according to one of Claims 1 to 4, characterized in that the silver and/or the ruthenium is/are present at least partially in the form of a metal compound, the metal compound being at least one metal oxide, metal oxyhydrate, metal hydroxide, metal oxyhydroxide, metal halide and/or at least one metal sulfide includes. A method for producing a fiber material with an antimicrobial effect, in particular the fiber material according to any one of claims 1 to 5, which comprises the following steps: a) providing pulp which comprises cellulose and/or cellulose derivatives, b) optionally producing a solvent system which comprises at least one solvent and water, c) mixing the pulp with at least one solvent and water, or optionally with the solvent system according to b), to produce a pulp, d) dissolving the cellulose and/or cellulose derivatives in the pulp to produce a spinning solution; e) pressing the spinning solution through spinnerets and f) regenerating the cellulose and/or cellulose derivatives to produce modified cellulose - and/or cellulose derivative - fibers, characterized in that the pulp and/or the spinning solution and/or optionally the solvent system at least one antimicrobial

Drug component is added, which includes silver (Ag) and ruthenium (Ru). Method according to Claim 6, characterized in that the antimicrobial active ingredient component is added in solid form, in particular as a powder, and dispersed in the pulp and/or the spinning solution and/or optionally the solvent system. Process according to Claim 6 or 7, characterized in that the antimicrobial active ingredient component in solid form, in particular as a powder, is first dispersed in the solvent system and the dispersion produced in this way is then added to the pulp. Method according to one of Claims 6 to 8, characterized in that the pulp is homogenized after the addition of the antimicrobial active ingredient component. Method according to one of claims 6 to 9, characterized in that silver and ruthenium are added at least partly in the form of silver metal particles which are partly coated with metallic ruthenium. Method according to one of Claims 6 to 10, characterized in that silver and ruthenium are added at least partially in the form of particles which comprise a carrier material on which silver and ruthenium are applied. Method according to claim 11, characterized in that the carrier material comprises cellulose and/or at least one cellulose derivative. Process according to any one of Claims 6 to 12, characterized in that the solvent is N-methylmorpholine N-oxide (NMMO). Fibrous material produced in the method according to one of Claims 6 to 13. Use of the fibrous material according to one of Claims 1 to 5 or 14 for the production of wound dressings, wound dressings and/or plaster materials.