EP4187004A1 - Fibre material with antimicrobial and odour-neutralising effect - Google Patents

Abstract

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 an antimicrobial active component as a means of reducing or preventing odors in textile fiber materials. The active ingredient component of the fiber material according to the invention comprises metallic silver (Ag) and metallic ruthenium (Ru), silver and ruthenium being in contact with one another and embedded in the cellulose and/or cellulose derivative fibers and/or at least partially surrounded by them. The fiber material according to the invention has not only antimicrobial properties, but also advantageously deodorizing and/or odor-neutralizing properties. 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.

Description

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 an antimicrobial active component as a means of reducing or preventing odors in textile fiber materials.

State of the art

Antimicrobial fibers, fiber composites, yarns and textile fabrics are known. Numerous publications such as the DE 10 2006 056977 B3 , DE 10 2007 019 768 A1 and DE 10 2008 045 290 A1 Additives made from antimicrobial, particulate, liquid or meltable or vaporizable active ingredients or active ingredient compounds made 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 fibers, fiber composites, yarns and fabrics functionalized in this way is the insufficient resistance and the resultant worsening or even non-existent effect that is difficult for the user to control, for example due to the active ingredients essential for the function being washed out.

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 to date on the production of antimicrobial cellulose has involved the introduction of biocidally acting nano-silver particles on or in the cellulose fibers through various deposition processes (e.g U.S. 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 , show a better resistance to washing out, but the effectiveness deteriorates after 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, cannot or only in very small amounts (<<1%) be introduced into the fiber matrix in the shaping step (solution production and fiber spinning). Also disadvantageous, especially with active ingredient concentrations of several percent by weight, as you would need for a constant effectiveness of conventional active ingredients, is the impairment of 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, yarns 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 metallic silver (Ag) and metallic ruthenium (Ru), silver and ruthenium being in 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, durability, dyeability, water absorption/absorbency and processability.

According to the invention, the active substance component comprises metallic silver (Ag) and metallic ruthenium (Ru), silver and ruthenium being in electrical contact with one another. Silver and ruthenium have different electrochemical potentials and thus form a galvanic cell (ie a "microgalvanic element"). If this cell is short-circuited via an aqueous phase, a high electric field strength is created due to the small distance (nm or µm 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 Ag/Ru metal combination is a catalytically assisted system, its antimicrobial effect is advantageously exclusively due to the active surface and not, as is the case with biocides or the oligodynamic systems (Silver, copper and zinc or their salts or compounds) depending 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 present at least partially in the form of silver/ruthenium bimetallic particles. 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/or the ruthenium is/are partially present in the form of a metal compound. The metal compound can include, for example, at least one metal oxide, metal oxyhydrate, metal hydroxide, metal oxyhydroxide, metal halide and/or 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)/Ru(VI), Ru(VI)/Ru(IV), Ru(IV)/Ru(III) and possibly Ru(III)/Ru(II) are the cause of the high catalytic activity of the 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. Therefore, the presence of several valences is a prerequisite for the catalytic effect and the redox reaction. So it doesn't have to be a ruthenium compound are 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 from it; 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.

1. a) Bereitstellen von Zellstoff, der Cellulose und/oder Cellulose-Derivate umfasst,
2. b) Optional Herstellen eines Lösungsmittelsystems, das mindestens ein Lösungsmittel und Wasser umfasst,
3. c) Mischen des Zellstoffs mit mindestens einem Lösungsmittel und Wasser, oder optional mit dem Lösungsmittelsystem gemäß b), zur Herstellung einer Pulpe,
4. d) Lösen der Cellulose und/oder Cellulose-Derivate in der Pulpe zur Herstellung einer Spinnlösung;
5. e) Pressen der Spinnlösung durch Spinndüsen und
6. f) Regenerieren der Cellulose und/oder Cellulose-Derivate zur Erzeugung modifizierter Cellulose - und/oder Cellulose-Derivat - Fasern,

wobei der Pulpe und/oder der Spinnlösung und/oder optional dem Lösungsmittelsystem mindestens eine antimikrobielle Wirkstoffkomponente zugegeben wird, die metallisches Silber (Ag) und metallisches Ruthenium (Ru) umfasst.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:

1. a) providing pulp comprising cellulose and/or cellulose derivatives,
2. b) optionally preparing a solvent system comprising at least one solvent and water,
3. c) mixing the pulp with at least one solvent and water, or optionally with the solvent system according to b), to produce a pulp,
4. d) dissolving the cellulose and/or cellulose derivatives in the pulp to produce a spinning solution;
5. e) pressing the spinning solution through spinnerets and
6. 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 metallic silver (Ag) and metallic 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. Unexpectedly, even for a person skilled in the art, it was found that the addition of the silver-ruthenium active substance component did not result in a reduction in the on-set temperature or any other disadvantageous impairment 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 has full antiviral effectiveness within from 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 wash-out-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 at least partially in the form of particles are added, which comprise a support material on which metallic silver and metallic 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 evenly distributed in the cellulose-containing solvent, 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 equipment from which particles can only be removed from the outside with a Magnets is possible (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 dissolves in the organic cellulose solution and the active ingredient component is finely distributed in the pulp, from which then cellulose threads can 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 metallic silver and metallic 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 often used in the production of regenerated fibers. Alternatively, however, other suitable solvents or solvent systems, such as N,N-dimethylbenzylamine-N-oxide or sodium hydroxide/carbon disulfide (NaOH/CS2), can also be used as solvents for the cellulose or cellolose 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. in terms of mechanical stability, service life, dyeability, water absorption/absorbency and processability. are comparable.

The object is also achieved according to the invention through the use of an antimicrobial active ingredient component which comprises 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 which were doped with the antimicrobial active component according to the invention after a uniform loading time of 180 minutes after just 60 minutes could no longer be perceived. 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 ingredient component according to the invention.

Because of the properties mentioned, yarns, knitted fabrics or woven 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 yarns 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, yarns, 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 using active ingredient dispersions and subsequent fixing of the active ingredient by drying, for example, coating using special techniques such as ultrasonic impregnation or the like is also possible.

"Regenerate fibers" within the meaning 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 consists mainly 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 substance combination, 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 context of the invention refers to the combination of two different metals, each of which has an electrode (anode or cathode). 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" also includes alloys comprising at least two different metals, 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

• figure 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).
• figure 2 shows a bar chart of the antibacterial effectiveness of a cellulose thread produced using a lyocell process: Effect of a particulate cellulose-based silver-ruthenium hybrid against Staphylococcus aureus (DSM 799). $$\mathrm{K}=\mathrm{control}\left(\mathrm{Tula}\mathrm{organic}-\mathrm{Cotton},100\mathrm{\%}\right)$$
  
  $$\begin{array}{c}425-01=\mathrm{fleece}\mathrm{out\; of}\mathrm{lyocell}-\mathrm{fibers}\mathrm{with}1\mathrm{\%}\mathrm{cellulose}-\mathrm{silver/ruthenium}-\mathrm{particles}\\ \mathrm{after}50\mathrm{washes}\end{array}$$
  
• figure 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). $$\mathrm{K}=\mathrm{control}\left(\mathrm{Tula}\mathrm{organic}-\mathrm{Cotton},100\%\right)$$
  
  $$\begin{array}{c}425-01=\mathrm{fleece}\mathrm{out\; of}\mathrm{lyocell}-\mathrm{fibers}\mathrm{with}1\mathrm{\%}\mathrm{cellulose}-\mathrm{silver/ruthenium}-\mathrm{particles}\\ \mathrm{after}50\mathrm{washes}\end{array}$$
  
• figure 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). $$\mathrm{K}=\mathrm{control}\left(\mathrm{Polyester\; fleeces}\mathrm{f}5\right)$$
  
  $$426-01=\mathrm{lyocell}-\mathrm{fibers}\mathrm{without}\mathrm{modification},100\%$$
  
  $$\begin{array}{c}426-02=\mathrm{fleece}\mathrm{out\; of}\mathrm{lyocell}-\mathrm{fibers}\mathrm{with}1\mathrm{\%}\mathrm{cellulose}-\mathrm{silver/ruthenium}-\mathrm{particles}\\ \mathrm{after}50\mathrm{washes}\end{array}$$
  
• figure 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). $$\mathrm{K}=\mathrm{control}\left(\mathrm{Tula}\mathrm{organic}-\mathrm{Cotton},100\%\right)$$
  
  $$434-01=\mathrm{zero\; sample},\mathrm{washed}$$
  
  $$\begin{array}{c}434-02=\mathrm{fleece}\mathrm{out\; of}\mathrm{lyocell}-\mathrm{fibers}\mathrm{with}1\mathrm{\%}\mathrm{cellulose}-\mathrm{silver/ruthenium}-\mathrm{particles}\\ \mathrm{after}\mathrm{100}\mathrm{washes}\end{array}$$
  
  $$434-03=\mathrm{fleece}\mathrm{out\; of}\mathrm{purer}\mathrm{cellulose},100\%$$
  
• figure 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). $$\mathrm{K}=\mathrm{control}\left(\mathrm{polyester\; fleece}\mathrm{f}5\right)$$
  
  $$435-01=\mathrm{zero\; sample},\mathrm{washed}$$
  
  $$\begin{array}{c}435-02=\mathrm{fleece}\mathrm{out\; of}\mathrm{lyocell}-\mathrm{fibers}\mathrm{with}1\%\mathrm{cellulose}-\mathrm{silver/ruthenium}-\mathrm{particles}\\ \mathrm{after}100\mathrm{washes}\end{array}$$
  
  $$435-03=\mathrm{fleece}\mathrm{out\; of}\mathrm{purer}\mathrm{cellulose},100\%$$
  
• figure 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). $$\mathrm{K}=\mathrm{control}\left(\mathrm{Tula}\mathrm{organic}-\mathrm{Cotton},100\%\right)$$
  
  $$434-01=\mathrm{zero\; sample},\mathrm{washed}$$
  
  $$\begin{array}{c}434-02=\mathrm{fleece}\mathrm{out\; of}\mathrm{lyocell}-\mathrm{fibers}\mathrm{with}1\%\mathrm{cellulose}-\mathrm{silver/ruthenium}-\mathrm{particles}\\ \mathrm{after}100\mathrm{washes}\end{array}$$
  
  $$434-03=\mathrm{fleece}\mathrm{out\; of}\mathrm{purer}\mathrm{cellulose},100\%$$
  
• 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

figure 1 shows the antimicrobial effectiveness of an antimicrobial cellulose thread produced by the Lyocell process, which was produced by adding a cellulose-based silver/ruthenium active ingredient component to the Lyocell process, against E. coli (DSM 498) using the around the thin A thread of inhibition zone developed around it.

Figures 2 to 7 show the significant antimicrobial effect of cellulose Ag/Ru threads produced using 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 titer 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 up to a total of 2 kg with sheets made of 100% cotton. 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 basis weight of the wet webs 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 webs. To clarify the influence of the washing, unmodified cellulose fibers were also washed and, in addition to a control (PET) and high-purity cotton (Tula organic cotton), evaluated with regard to the antimicrobial effect.

• Staphylococcus aureus - gram positiv; stark wirksam
• Klebsiella pneunomiae - gram negativ; stark wirksam

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 metallic silver (Ag) and metallic 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.

figure 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 non-woven fabric was rated clear to strong. The Ag/Ru active ingredient component 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 substance 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. Polyester fabrics, for example, release odor molecules more quickly or more easily (ie in greater numbers) than cotton. From this fact one can conclude that the odor molecules are held inside the cotton or cellulose fibers so that they are effectively neutralized by an embedded antimicrobial active component comprising metallic silver (Ag) and metallic ruthenium (Ru). can become.

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 dry weight of pulp) are added to the mixture, and everything is 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 pressure change (dp/dT) _max. 153 °C, is manually transferred to a storage vessel and at 80 °C degassed.

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 N ₂ 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 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 particle size D ₉₀ ≤ 8 μm) is dissolved in 1 l using an Ultra-Turrax high-performance disperser aqueous NMMO (60%, w/w) and, after a standing time of 30 minutes, added to a pulp made from 377 g of cellulose (MoDo, DP: 590, solids content: 95.5%) and 3,372 g of NMMO. The modified pulp is again homogenized 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 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 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 homogeneous mixture of 36 g of a ZnO/ZnS mixture (1:2, w/w, each D ₉₉ ≤ 2 µm) and 0.5 l of 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 ^rpm for 15 minutes and then, analogously to previous examples 1 or 2, to staple fibers with a length of 40 mm, a fineness of 1.5 dtex, a tensile strength of 35.4 cN/tex, one Elongation at break of 14.2% and a loop tearing strength related to the fineness 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 will then added to a pulp of 377 g of cellulose (analogously to Example 2) and 3,872 g of NMMO and everything was homogenized together again at 10,000 ^rpm 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 post-treated analogously to Example 1 have a final fineness of 1.76 dtex, a tensile strength of 42 cN/tex, an elongation at break of 13.6% and a loop strength of 14.4 cN/tex, and are therefore the fibers Example 1 completely equivalent.

Example 5 (Antimicrobial Efficacy of Non-Functionalized Samples)

The antibacterial effectiveness (based on DIN EN ISO 20743:2013 absorption method) was determined against both gram-positive (Staphylococcus aureus) and 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 Δlog of 4.0 (Example 2) or 3.4 (Example 3) compared to Staphylococcus aureus and 3.8 (Example 2) or 3.1 (Example 3) compared to 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 Δlog 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 effectiveness of fibers with a silver/ruthenium finish)

Fibers produced analogously to example 1 and example 4 were cut into short staple fibers with staple lengths of ≦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. After the end of the washing test, the washed nonwovens were each opened separately, redispersed in deionized water and placed back into the short-fiber nonwoven using Rapid Köthen sheet formers.

Table 1 shows the results of the independently performed antimicrobial studies. <b>Table 1</b>: Reduction in the test germ concentration after the specified number of washes Test germ reduction 0 washes Test germ reduction 50 washes Test germ reduction 100 washes Δlog* SA Δlog* KP M _V ** Phi 6 Δlog* SA Δlog* KP M _V ** Phi 6 Δlog* SA Δlog* KP M _V ** Phi 6 PET control - - 0 - - 0 - - 0 Tula organic cotton 0 0 - 0 0 - 0 0 - 100% Example 1 0.4 -0.1 - - - 0.33 0.3 0.1 -0.05 70% Ex 1 / 30% Ex 4 5.2 5.7 4.9 3.7 3.7 4.84 4.2 4.9 4.67 * Antibacterial efficacy, Δlog = (Ig c _{t control , 24h} - Ig c _{0 control, 0h} ) - (Ig c _{t sample, 24h} - Ig c _{0 sample, 0h} )
** Antiviral potency, M _V = Ig V _R - Ig V _C , where V _R = mean logarithm of phage titers after 2 h exposure to the reference sample V _C = mean logarithm of phage titers after 2 h exposure to the antiviral sample
Δlog ≥ 3 = highly effective; 3 > Δlog > 2 = significantly effective; 2 > Δlog ≥ 0.5 = weakly active, Δlog < 0.5 not active M _v ≥ 3 = full antiviral efficacy; 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 (18)

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,
that the active substance component comprises metallic silver (Ag) and metallic ruthenium (Ru), silver and ruthenium being in contact with one another and in the cellulose - and/or cellulose derivative - fibers being embedded and/or at least partially surrounded by them. Fibrous material according to claim 1, characterized in 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. Fibrous material according to Claim 1 or 2, characterized in that silver and ruthenium are present at least partially in the form of silver/ruthenium bimetallic particles. Fibrous material according to Claim 3, characterized in that the silver/ruthenium bimetallic particles comprise silver particles which are partially coated with ruthenium. Fibrous material according to Claim 3 or 4, characterized in that the silver/ruthenium bimetal particles comprise particles of cellulose and/or cellulose derivatives which are coated with silver and ruthenium. Fibrous material according to any one of Claims 1 to 5, characterized in that the silver and/or the ruthenium is/are partly in the form of a metal compound. Fibrous material according to Claim 6, characterized in that the metal compound comprises at least one metal oxide, metal oxyhydrate, metal hydroxide, metal oxyhydroxide, metal halide and/or at least one metal sulfide. Method for producing a fiber material with an antimicrobial effect, in particular the fiber material according to one of Claims 1 to 7, which comprises the following steps: a) providing pulp comprising cellulose and/or cellulose derivatives, b) optionally preparing 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 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,
that at least one antimicrobial agent component comprising metallic silver (Ag) and metallic ruthenium (Ru) is added to the pulp and/or the spinning solution and/or optionally to the solvent system. Method according to Claim 8, 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. The method according to claim 8 or 9, characterized in that the antimicrobial active component in solid form, in particular as powder, is first dispersed in the solvent system and the dispersion thereby produced is then added to the pulp. Method according to one of Claims 8 to 10, characterized in that the pulp is homogenized after the addition of the antimicrobial active ingredient component. A method according to any one of claims 8 to 11, characterized in that silver and ruthenium are added at least partially in the form of silver metal particles partially coated with metallic ruthenium. Method according to one of Claims 8 to 12, characterized in that silver and ruthenium are added at least partially in the form of particles which comprise a carrier material on which metallic silver and metallic ruthenium are applied. Method according to Claim 13, characterized in that the carrier material is 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. Method according to Claim 13 or 14, characterized in that the carrier material comprises cellulose and/or at least one cellulose derivative. Process according to any one of Claims 8 to 15, characterized in that the solvent is N-methylmorpholine N-oxide (NMMO). Fibrous material produced in the method according to any one of claims 1 to 16. Use of an antimicrobial agent component comprising metallic silver (Ag) and metallic ruthenium (Ru) as an agent for reducing or preventing odors in textile fiber materials.

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