WO2021083950A1

WO2021083950A1 - Antimicrobial finish of surfaces, and devices therefor

Info

Publication number: WO2021083950A1
Application number: PCT/EP2020/080267
Authority: WO
Inventors: Ralph Wilken
Original assignee: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung eingetragener Verein
Priority date: 2019-10-28
Filing date: 2020-10-28
Publication date: 2021-05-06
Also published as: EP4051738A1

Abstract

The invention relates to the use of a silver-filament-containing and/or copper-filament-containing rubbing device to produce an antimicrobial surface or to improve the antimicrobial properties of a surface.

Description

Antimicrobial finishing of surfaces and devices therefor

The present invention relates to the use of a silver filament-containing and / or copper filament-containing rubbing device for producing an antimicrobial surface or for improving the antimicrobial properties of a surface. It also relates to a method for producing an antimicrobial surface or to improve the antimicrobial properties of a surface and an object with a partially antimicrobial surface that was produced in a method according to the invention, and a friction device for use in the use according to the invention or in the method according to the invention.

The generation of antimicrobial surfaces often takes place in that surfaces are coated flatly with an antimicrobial material or in that antimicrobial substances are introduced into the surfaces. One approach to this is known, for example, from the application WO 2005/048708, in which nano-silver particles are introduced into the coating of corresponding surfaces.

Furthermore, a number of approaches are known in the prior art in which, for example, implants are coated with antibiotics on their surface.

Microsilver particles that are obtained e.g. through inert gas condensation, i.e. spherical particles, are used, for example, in skin cancer to improve wound healing, in varnishes or polymers to give components an antimicrobial finish.

The object of the present invention was to offer the simplest possible possibility of equipping a large number of surfaces with an antimicrobial effect or - if an antimicrobial effect is already present - to strengthen the latter. As a logical consequence, it was also the object of the present invention to specify the means for the new possibility, as well as the correspondingly antimicrobially improved surfaces. The primary object of the invention is achieved through the use of a silver filament-containing and / or copper filament-containing rubbing device to produce an antimicrobial surface or to improve the antimicrobial properties of a surface.

A friction device within the meaning of the present invention is a device which comprises> 2, preferably> 20, more preferably> 100 and most preferably> 1000 two filaments and the filaments of which are preferably held by a holder. Various joining techniques can be used to hold the filaments; clamping, clamping, screwing, gluing, welding, soldering, etc. is preferred. A preferred device for rubbing is a brush. In addition, friction devices also include sponges or pads, e.g. made of knitted filaments, even if there is no holder.

For the purposes of the present invention, a filament is a metallic wire whose length is significantly longer than its diameter. The cross-sectional area orthogonal to the longitudinal axis is preferably a circle or an ellipse, but can alternatively preferably also be a square, rectangle, triangle or other flat geometric shapes. In these cases, the diameter of the filament is understood to mean the diameter of the smallest circle that covers the respective cross-sectional area. An example area in the case of a square would be the diameter d = V2 I, where I is the edge length of the square.

A filament containing silver or copper is present in the sense of the present invention when the weight fraction of silver or copper is the main component of the respective alloy (or the pure substance), i.e. if the weight fraction of the respective element is greater than 50 wt. % is.

Silver-containing filaments are preferred according to the invention.

It is preferred that the silver filaments and / or copper filaments to be used according to the invention are soft-annealed. In the context of the present invention, soft annealed is to be understood as meaning that the filaments to be used according to the invention have been brought into a state by a heat treatment which has a nominal tensile strength in the case of copper <300 MPa, in the case of silver <250 MPa. Soft annealed filaments to be used according to the invention have been distinguished by a particularly suitable abrasion behavior.

In the case of filaments to be used according to the invention, it is preferred that the aspect ratio of the respective filament, i.e. length of the filament to diameter, is preferably <1000 and> 10, particularly preferably <500 and> 50 and most preferably <200 and> 100.

With these aspect ratios, particularly good elastic behavior can be observed for the filaments, which is beneficial for the use according to the invention.

The generation of an antimicrobial surface within the meaning of the present invention takes place when an antimicrobial surface has arisen. An antimicrobial surface is given when the reproduction of Staphylococcus epidermis is inhibited for at least 10 hours, measured as described in DE 19758598A1. It is determined whether bacteria, for example in the aforementioned type, can only produce less than 0.1% of daughter cells within 18 hours compared to the untreated surface. Alternatively and preferably, an antimicrobial surface is present if the antimicrobial properties are determined in accordance with ASTM E2149.

An antimicrobial surface is improved if the surface was already antimicrobial in the sense of the above definition before treatment and the antimicrobial effect is improved by at least 2% compared to the surface treated without the use according to the invention.

When the friction device is used according to the invention, the surface to be treated is generally rubbing with the friction device. For the purposes of the present invention, rubbing is a contacting of two surfaces, with at least one of the two surfaces, preferably both surfaces, being moved laterally to the contact surface. Rubbing can be a very short process. It goes without saying that contact pressure must always be present during the rubbing process. When rubbing in the sense According to the present invention, two solids are always contacted under the conditions mentioned. The rubbing preferably takes place in the form of brushes.

In the context of the present invention it has surprisingly been found that the use according to the invention leads to a sufficient amount of silver or copper material being transferred to a large number of surfaces to be treated so that an actual antimicrobial effect is developed. Rubbing with filaments, preferably in the form of brushes, is a process that is accessible on the vast majority of surfaces and can also be used over a large area and even mechanically. In addition, it is easily possible to repeat this process over and over with exposed surfaces if a decrease in the antimicrobial effect can be ascertained.

Without being bound to a theory, it is currently assumed that the tribological loading of the treated surface by the filaments leads to the formation of a transfer film or tribo film on the surface of the component, this tribo film comprising components of the friction device filaments. It is surprising that this simple process transfers such an amount of antimicrobially effective copper and / or silver that an actual antimicrobial effect can occur.

According to the invention, it is preferred that, when used according to the invention, the friction device also comprises filaments of harder material, preferably brass and / or bronze, in order to protect silver-containing filaments and / or copper-containing filaments made from a softer alloy or from the respective pure substance from excessive mechanical stress , especially in the context of excessive abrasion or even in the context of inelastic deformations.

Alternatively or additionally, it can be preferred according to the invention that the friction device also comprises elements made of plastic. Here, the person skilled in the art will select the particular plastic used for the specific function of the plastic filaments used. For example, it can be preferred that the plastic filaments have a primary dirt-releasing function, while the silver-containing and / or copper-containing filaments to be used according to the invention essentially serve to impart an (possibly improved) antimicrobial property to the processed surface via suitable abrasion. According to the invention, a use according to the invention is preferred, the generation of an antimicrobial surface or the improvement of the antimicrobial properties of the surface by transferring silver-containing and / or copper-containing particles which, in plan view, have a largest diameter of 2 to 15 μm and in section perpendicular to the axis of this largest diameter have a maximum thickness of 200 nm to 2 pm.

For the purposes of the present invention, a silver or copper-containing particle is present when the weight fraction of silver or copper in the respective particle is> 50% by weight. Surprisingly, it has been shown that even by rubbing in the use according to the invention, particles of a particular shape are produced to a sufficient extent which bring about the antimicrobial effect. This already works when components on the surface or components of a coating of a surface have a similar, preferably higher hardness than in the silver-containing and / or copper-containing filaments to be used according to the invention.

The particles transferred to the treated surface in the use according to the invention preferably have a non-spherical shape.

For the purposes of the present application, the top view for determining the extent of the individual particles is the viewing axis parallel to the surface normal of the surface on which the respective particle is located.

The greatest thickness of the respective particle in the sense of the present invention is the greatest length of the respective measured section in the direction of the surface normals of the surface.

A use according to the invention is preferred in which the aspect ratio V of the greatest diameter in plan view to the greatest thickness of the silver-containing and / or copper-containing particles 1000: 1>V> 1.2: 1, preferably 500: 1>V> 1.5: 1, further preferably 200: 1>V> 2: 1, more preferably 100: 1>V> 3: 1, more preferably 100: 1>V> 5: 1, more preferably 50: 1>V> 9: 1. These aspect ratios of the silver-containing or copper-containing filaments to be used according to the invention are particularly suitable for transferring a sufficient amount of antimicrobial active ingredients in the form of silver and / or copper to the respective surface to be treated, so that an antimicrobial effect arises. In the case of silver, for example, particularly small amounts of <5 atom% silver, measured by means of XPS and based on the elements detected by means of XPS, are sufficient to produce the desired effect.

Another advantage of using a friction device is that the tribological stress on the uppermost layer of the surface to be treated can remove any contamination from this surface and remove the uppermost, possibly contaminated layer, so that the surface to be treated can be removed at the same time is cleaned.

A use according to the invention is preferred, with silver-containing and / or copper-containing particles being transferred to the surface in such a way that a surface coverage A of 5%>A> 0.01%, preferably 2%> ^{, is obtained on an area of at least 0.25 mm 2} A> 0.02%, more preferably 1%>A> 0.03%, more preferably 0.5%>A> 0.04% results from the transferred particles.

A use according to the invention is particularly preferred, with silver-containing and / or copper-containing particles being transferred to the surface in such a way that, even after cleaning for 1 minute in an ultrasonic bath filled with deionized water, an area of at least 0.25 mm ^{2 has} a surface coverage A of 5 %>A> 0.01%, preferably 2%>A> 0.02%, more preferably 1%>A> 0.03%, more preferably 0.5%>A> 0.04% results from the transferred particles .

In case of doubt, cleaning is carried out for 1 minute at room temperature in the SONOREX SUPER RK 31 ultrasonic bath from BANDELIN electronic GmbH & Co. KG.

According to the definition, in the context of the present invention, the degree of surface coverage A is determined via a (light) microscopic evaluation. If the contrast is not high enough or the particles are too small to be detected with a light microscope, SEM / EDX can be used as an alternative. It is easy for a person skilled in the art to determine how often he has to guide the friction device over the respective surface (and / or at what contact pressure) that a corresponding degree of coverage is generated.

A use according to the invention is preferred, whereby the surface silver-containing and / or copper-containing particles are also transferred in such a way that a surface concentration c of 10 at%>c> 0.005 at%, preferably 5 ^{, is found on an area of at least 0.25 mm 2} at%>c> 0.01 at%, more preferably 2 at%>c> 0.05 at%, more preferably 1 at%>c> 0.08 at% silver and / or copper results from the transferred particles,

It is preferred according to the invention that the surface concentration c is determined by an XPS measurement in plan view.

A use according to the invention is preferred, the silver-containing and / or copper-containing filaments of the friction device

a diameter of <2 mm and> 10 μm, preferably <1 mm and> 5 μm, more preferably <1 mm and> 150 μm, even more preferably <1 mm and> 200 μm and particularly preferably <800 and> 400 pm and / or

- a Vickers hardness of 25-200, preferably 40-100 and / or

- have a nominal tensile strength of <600 MPa and> 10 MPa, preferably <500 MPa and> 50 MPa, more preferably <400 MPa and> 200 MPa and / or

- have an aspect ratio length to diameter <1000 and> 10, particularly preferably <500 and> 50, more preferably <250 and> 100.

These special designs of the filaments - individually or in combination - are particularly suitable for transferring the desired amount of antimicrobial active ingredients to the surface to be treated. This is not a matter of course, since without the knowledge of the present invention the person skilled in the art would have been inclined to select filaments (in particular bristles) with a high modulus of elasticity and high hardness as well as high tensile strength in order to counteract premature wear and tear and to reliably transfer forces to the surface to be able to without plastically deforming the filament material. Commercially available brass or bronze brushes have many hard brass filaments, typically made of CuZn36, CuZn37 or CuSn6, which usually have nominal tensile strengths of over 600 MPa. It has surprisingly been found that with such tensile strengths, not all preferred, desired aspects of the present invention, such as a low impact on the surface topography with a simultaneous high transfer of silver-containing and / or copper-containing particles, can be met to a high degree.

Furthermore, the person skilled in the art would have preferred hard filaments in order to bring about sufficient adhesion of the silver-containing and / or copper-containing particles to the surfaces during cleaning, in particular aqueous cleaning. A person skilled in the art would have assumed that if hard filaments were used, a sufficient triboplasm would arise, which promotes the intimate connection of the particles with the surface. This good adhesion of the particles, especially in the case of aqueous cleaning, would be necessary to ensure an antimicrobial effect after wiping cleaning.

The aspect ratio of the filaments used, that is to say the length of the filaments to the diameter, is preferably <1000 and> 10, particularly preferably <500 and> 50, and most preferably <250 and> 100. With these aspect ratios, particularly good elastic behavior can be observed for the filaments, without being plastically deformed in the case of small differences in height of the surface to be pretreated. Furthermore, with these aspect ratios it is ensured that the filaments can exert an advantageous normal force on the surface of the body to be treated.

In order to set both abrasiveness and wear of the filaments, the person skilled in the art sets the angle in a targeted manner, preferably from the filament orientation and the motion vector of the surface to be treated. An angle> 90 ° is often disadvantageous because in this case the filaments are plastically deformed very quickly (the filaments buckle). Too small an angle is disadvantageous because the contact point of the filaments with the electrical steel sheet cannot be exclusively at the end of the filament and the bristles can wear out significantly more quickly. The person skilled in the art therefore preferably selects angles between 2 and 80 °, particularly preferably between 10 and 70 °, more preferably between 25 and 60 °, most preferably 45 °. In general, when selecting the suitable friction means, in particular the filaments for the friction devices to be used, brushes are preferred, the hardness should be chosen so that it is not significantly harder than the surface to be treated in order to ensure that it is too strong and to prevent unwanted abrasion. For this purpose, the person skilled in the art will use filaments adapted to the body to be treated. This is particularly relevant if the body to be treated already has special surface properties. These properties can be color and design (through applied lacquers and paints, metallizations, other coloring coatings) and / or other functions such as adhesive properties, adsorption properties, surface reactivity, wetting properties, mechanical properties, storage properties, insulation properties, electrical conductivity, Thermal conductivity, sliding properties (e.g. with aerodynamically favorable surfaces), anti-ice properties, anti-frost properties, anti-fouling properties and / or reflective properties.

At the same time or in addition, the person skilled in the art will choose the filament diameter so that, on the one hand, a sufficient transfer of silver-containing and / or copper-containing particles is ensured, but on the other hand, the grooves created by the filaments on the treated body surface are not too large and, in particular, not too deep. Although a brush with a small filament diameter allows better contact with the surface to be treated (each filament has a point of contact with the surface), surprisingly less material is transferred to the surface. For example, when using 125 μm filaments, the degree of surface coverage is lower by a factor of ~ 7 than when using 500 μm filaments. Furthermore, when using 125 μm filaments, the degree of surface coverage is reduced by a factor of 15 through aqueous ultrasonic cleaning. When using 500 μm filaments, the degree of surface coverage is advantageously only reduced by a factor of 9 by aqueous ultrasonic cleaning. It was not foreseeable that way.

On the other hand, too large a filament diameter leads to the undesired inhomogeneous transfer of silver-containing and / or copper-containing particles in the form of individual traces, which can lead to an undesired inhomogeneous antimicrobial effect. Furthermore, the special surface properties mentioned above can be adversely affected.

Without being tied to a theory, it is to be expected that the rubbing (especially brushing) will result in tribological stress on the body surface, possibly with the formation of a tribo-plasma. This can lead to the formation of a transfer film or tribological film which includes the components of the friction means and components of the body surface and remains on the body surface. In the use according to the invention, it is preferred that the friction means is a brush with preferably silver-containing bristles (as filaments) is selected from the group consisting of plate brushes, plate brushes, strip brushes, sword brushes, cup brushes, conical brushes, roller brushes, round brushes and spiral brushes. These types of brushes have proven to be particularly suitable for the method according to the invention, it being further preferred that the brush used performs a rotating movement on the body to be treated.

In the use according to the invention, preference is also given to using a device for surface treatment, comprising a rubbing device, in particular a brush with silver-containing filaments, the device adjusting and, if necessary, regulating the force of the filaments on the surface to be treated. The device is preferably designed in such a way that contact with the body to be treated can be established by pressing at least over two wheels, preferably 3 or 4 wheels. The wheel treads preferably span a plane. The filaments are preferably oriented 45 ° to this plane and penetrate this plane. By pressing the rollers onto the surface of the preferably flat body, the filaments are elastically deformed and exert a force on the surface of the body to be treated.

Alternatively, it is preferred that, in the case of rotating brushes, the force of the filaments on the surface to be treated is controlled by selecting the rotation speed. For this purpose, the filaments are oriented at an angle between 2 and 80 °, preferably between 10 and 70 °, more preferably between 25 and 60 ° and particularly preferably 45 ° to the surface normal of the filament holder, preferably the brush back, and 90 ° to the axis of rotation. When rotating, the filaments are elastically deformed outwards by centrifugal force and increase the force of the filaments on the surface to be treated. In the context of the use according to the invention, it can be preferred according to the invention that, after the antimicrobial surface has been produced, the transferring copper-containing and / or silver-containing particles are fixed so that they can adhere better to the surface. This fixation is preferably carried out with a binder-containing solution and / or dispersion, very particularly preferably with a propolis-containing solution. The synergistic effect of propolis and copper and in particular silver should be mentioned in particular, without being bound by any particular theory. Against the background, the present invention is particularly suitable for use on beehives, because the bees subsequently - i.e. after transferring the copper-containing or silver-containing particles - usually coat the treated surfaces with propolis. This creates an effective and long-lasting antimicrobial effect on the surface. The use according to the invention can preferably also be used on (still) sticky surfaces. This also leads to a good fixation of the transferred copper-containing and / or silver-containing particles. It may also be possible to subject surfaces that have not yet hardened to the use according to the invention.

Alternatively, it can be preferred to set the tack (surface tack) of the surface to be treated in a targeted manner before the antimicrobial surface is produced. To increase the strength, the person skilled in the art uses suitable resins, preferably propolis, or alternative binder systems. The surface tack can be lowered by hardening, by wetting with oils and / or by coating with powders.

Furthermore, it can be preferred to set the roughness of the surface to be treated in a targeted manner prior to generating the antimicrobial surface. Abrasive processes such as grinding, blasting, milling or laser processes can be used for this. With the targeted adjustment of the roughness, the amount and shape of the copper-containing or silver-containing particles transferred during the use according to the invention can be controlled.

Furthermore, it can be preferred to set the adhesive properties of the surface to be treated in a targeted manner before the antimicrobial surface is produced. For example, plasma processes, irradiation, in particular with vacuum UV radiation, flame treatment, and laser processes are used for this purpose.

A use according to the invention is preferred, the treated surface comprising or consisting of a material selected from the group consisting of paper, in particular wallpaper, cardboard, plastic, foils, lacquer, paint, plasma polymer coating, diamond and diamond-like coatings, metal, metallic coatings , Ceramics, metal-oxide coatings, silicon-containing coatings, glass, in particular frosted glass, concrete, stone, wood, fabric, fleece, knitted fabric, fabric, bone, horn, tooth, scales, skin and hair. For these materials it has been shown that it is easily possible for the person skilled in the art to select suitable filaments and to achieve the effects desired through the use according to the invention.

Part of the present invention is also a method for producing an antimicrobial surface, namely comprising the steps of a) providing a surface to be treated, preferably as defined above as preferred, b) providing a silver filament-containing and / or copper filament-containing rubbing device, preferably as above as preferably defined, c) wiping over the surface to be treated with the rubbing device, preferably in such a way that silver-containing and / or copper-containing particles are transferred to the surface, preferably in a form and / or surface concentration or in another way, as defined above, with the proviso that if the rubbing device comprises filaments containing copper, the surface to be treated made available is not a surface of an electrical steel sheet.

For the method according to the invention, it is preferred that silver filament-containing friction devices are provided in step b), the friction device also being able to include copper-containing filaments, but also not being able to include any copper-containing filaments.

This method according to the invention makes it possible to use the inventive use of the friction device according to the invention in such a way that an antimicrobial surface is generated or the antimicrobial surfaces of a surface, namely the treated one, are improved.

Part of the invention is also an object with at least partially antimicrobial surface, which is produced by a method according to the invention, or an object with at least partially antimicrobial surface, comprising silver-containing and / or copper-containing particles, as defined in more detail above, with the proviso that if the surface is a surface of an electrical steel sheet, silver-containing particles are also included, it being generally preferred that, in addition to copper-containing particles, also silver-containing particles Particles are included and it is further preferred that, in addition to silver-containing particles, no copper-containing particles are included.

This subject according to the invention is the result of the use according to the invention and / or the method according to the invention. The respective antimicrobial surfaces can be easily created.

Part of the invention is also an object according to the invention, selected from the group consisting of beehive, wallpaper, medical product or part thereof, in particular implants, crockery, cutlery, door, handles, preferably door handles or handles of shopping carts, fittings, switches, sockets, panels, Garment, claw, hoof, fingernail, tooth, skin, fur, wall (in terms of architecture), window frame, window pane, floor covering, preferably laminate, parquet, linoleum, PVC, tile, tile, carpet, sanitary ware, beds (bed frames, bed boxes), Chairs, tables, tabletops, worktops (especially for kitchens), household appliances, mobile devices, keyboards, mice and mouse pads.

For these objects it is very easily possible to apply the method according to the invention or the use according to the invention in order to produce the desired antimicrobial effects, possibly also repeatedly.

The invention also includes a rubbing device, especially a brush, especially a brush selected from the group consisting of a plate brush, a plate brush, a strip brush, a sword brush, a cup brush, a bevel brush, a roller brush, a round brush and a spiral brush, which is suitable for a use according to the invention or an inventive one Method with the proviso that the friction device comprises silver-containing filaments, preferably as in an embodiment described above as preferred.

So far there has been no reason to create a corresponding friction device, since its use only appears sensible through the present invention. A friction device according to the invention is preferred, the filaments being oriented at an angle between 2 and 80 °, preferably between 10 and 70 °, more preferably between 25 and 60 ° and particularly preferably 45 ° to the surface normal of the filament holder, preferably the brush back.

This angle setting makes it possible to achieve the effects desired in the invention in a particularly suitable manner. The invention can be applied in a variety of technical fields. It is particularly preferably used on substrates in the field of medical technology, human medicine, veterinary medicine, on technical surfaces and on surfaces that require special antimicrobial protection, such as the flyboards of beehives or the surfaces of beehives. In principle, it is also possible to apply the invention to biological surfaces. It may be that, for patent reasons, the invention is excluded for methods of surgical or therapeutic treatment of the human or animal body. The friction device according to the invention is preferably part of a cleaning system, in particular as part of a vacuum cleaner, preferably as part of a vacuum cleaner with an actively moving brush head. Examples of this are described in DE2318425 A1 and DE 10 2015 106 094 A1.

For this use, it is particularly preferred that the brushes, in addition to silver and / or copper filaments to be used according to the invention, preferably silver filaments, have further bristles that protect the silver and / or copper filaments, preferably silver filaments, to be used according to the invention from excessive abrasion and excessive mechanical stress, in particular protect against kinking. It is further preferred that the non-silver filaments are preferably aligned between 60 and 120 °, more preferably between 80 and 100 ° to the surface normal of the filament holder, preferably the brush back, and the silver and / or copper filaments to be used according to the invention, preferably silver filaments, at an angle between 2 and 80 °, preferably between 10 and 70 °, more preferably between 25 and 60 ° and particularly preferably 45 ° to the surface normal of the filament holder, preferably of the brush back. Thus, the silver and / or copper filaments to be used according to the invention, preferably silver filaments, are effectively protected from excessive stress.

Examples:

Measurement example 1a): Determination of the silver content with ESCA (XPS) with an improved detection limit for silver.

The XPS examinations were carried out with a Thermo K-Alpha K1102 system with an upstream switch argon glove box for handling air-sensitive samples. Parameters: acceptance angle of the photoelectrons 0 °, monochromatized AI Ka excitation, constant analyzer energy mode (CAE) with 150 eV passenger energy in overview spectra (step size 0.5 eV, 2 scans with a recording time of 9 minutes, 4.2 seconds) and in the High-energy Ag 3d spectra (step size 0.05 eV, 10 scans with a recording time of 12 minutes 21 seconds). The high-resolution Ag 3d spectrum is used to quantify the silver.

Analysis area: 0.40 mm 0. The neutralization of electrically non-conductive samples is carried out by a combination of low-energy electrons and low-energy argon ions. To compensate for charging effects, the C1s main photoemission line to be assigned to the C-C / C-H species is set at 285 eV during the evaluation, which means that the positions of the other photo lines are shifted accordingly.

The quantification takes place on the basis of documented relative sensitivity factors of the elements taking into account the specific analyzer transmission function based on the assumption of a homogeneous distribution of the elements within the XPS information depth (approx. 10 nm). The detection limit of the method is element-specific and is approx. 0.1 at%. Due to the measurement conditions and the sensitivity factor of silver, the detection limit of silver in the measurements is 0.005 at%

The measurement conditions mentioned are preferred in order to enable extensive independence from the type of spectrometer. Measurement example 1 b): Determination of the copper content with ESCA (XPS) with an improved detection limit for copper.

The XPS examinations were carried out with a Thermo K-Alpha K1102 system with an upstream argon glove box for handling air-sensitive samples. Parameters: angle of acceptance of the photoelectrons 0 °, monochromatized AI Ka excitation, constant analyzer Energy mode (CAE) with 150 eV passenger energy in overview spectra (step size 0.5 eV, 2 scans with a recording time of 9 minutes 4.2 seconds) as well as in the energetically high-resolution Cu 2p spectra (step size 0.05 eV, 15 scans with a recording time of 20min 1, 5 seconds). The high-resolution Cu 2p3 / 2 spectrum is used to quantify the copper.

The quantification takes place on the basis of documented relative sensitivity factors of the elements taking into account the specific analyzer transmission function based on the assumption of a homogeneous distribution of the elements within the XPS information depth (approx. 10 nm). The detection limit of the method is element-specific and is approx. 0.1 at%. Due to the measurement conditions and the sensitivity factor of copper, the detection limit of copper in the measurements is 0.005 at%. The same applies to the detection limit of silver.

The measurement conditions mentioned are preferred in order to enable extensive independence from the type of spectrometer.

Measurement example 2: light microscopy:

A Keyence digital microscope VHX 600 with objective VH-Z 100 and ring light source OP-72404, magnification 700x is used.

The particles can be seen in plan view; the Ag particles can be seen particularly well on white emulsion paint. Cu particles can also be reliably identified.

If the contrast between the particle and the substrate is too low, a measurement is made with SEM and EDX element mapping. Measurement example 3: REM-EDX:

A primary electron beam is generated with the help of an electrode cathode and acceleration towards the anode and is focused as finely as possible on the surface of the sample to be examined by subsequent electromagnetic lenses. In the sample, secondary electrons (SE), backscattered electrons (BSE) and X-rays are generated in an interaction volume that is dependent on the acceleration voltage and the material composition. The energy of the X-rays depends on the atomic number of the emitting atom and is therefore “characteristic” of the element in question. All of these signals can be registered with appropriate detectors. Corresponding topography, material and / or element contrasts can be mapped in this way.

EDX is a method for the spatially resolved element analysis of solids. The energy-dispersive X-ray microanalysis enables the element composition to be determined on a surface imaged by means of SEM. In addition to area and spot measurement, element mappings can also be recorded. A person skilled in the art selects the acceleration voltage so that it reliably detects the particles as a function of the adhesive layer thickness, typically 15 keV.

Applied device: High-resolution analytical FE-SEM Leo 1530 Gemini with EDX (Oxford INCA with Si and Germanium detector).

Measurement example 4: FIB cut and EDX measurement The silver or copper particles, in particular the thickness of the particles, can also be measured with SEM / EDX after the surface has been prepared by means of Fast Ion Bombardment (FIB) at the point of a particle.

For the preparation of the cross-section with the FEI Helios 600 Dualbeam, after the particle had been localized, an approximately 30 x 2 x 1pm thick platinum / carbon protective layer was first applied directly over the particle by means of ion-induced deposition (IBID, ion-beam induced deposition) deposited. Then a cross-section was prepared with the help of Ga + ions (30kV, 21 nA) and this cross-sectional area was finally polished (30kV, 2.8nA). The cross-section produced in this way could be imaged in-situ in the FEI Helios 600 DualBeam using secondary electrons. The secondary electron images are at 5kV and 0.17nA. Furthermore, the cross-sectional area was examined for its elemental composition by means of energy dispersive X-ray analysis (EDX). The selected parameters for this examination (10kV, 1.4nA or 0.69nA) enable the detection of all occurring elements with the highest possible lateral resolution. Measurement example 5: Determination of the antimicrobial properties

The measurement of the antibacterial properties of the surfaces was carried out in accordance with ASTM E2149.

Measurement example 6: Alternative determination of the antimicrobial properties

The measurement of the antibacterial properties of the surfaces was carried out in accordance with ISO 22196. In deviation from the standard, test specimens with the dimensions 20mm x20mm were used.

Measurement example 7: Determination of the surface coverage by means of SEM

The following device was used to record the particle distribution images of the secondary electrons: High-resolution analytical FEI Helios 600 Dualbeam Measurement parameters: Acceleration voltage: 10 keV / current 0.69 nA, magnification 500-fold (for example 8 and 9), 250-fold (for example 10) / CBS detector / Tilt angle: 0 °

Exemplary embodiment 1a: Silver brush A brush is made from a soft-annealed silver wire as follows:

Silver filaments are clamped tightly in one row in two clamping jaws, so that the filament length outside the clamping jaws is 30mm. The filaments consist of silver wire (supplier Goodfellow, 99.99%, annealed, diameter 250 μm). Exemplary embodiment 1b: copper brush A brush is made from a soft-annealed copper wire as follows:

In two clamping jaws, copper filaments are clamped tightly in one row, so that a filament length of 30mm results outside the clamping jaws. The filaments consist of copper wire (supplier Goodfellow, 99.9%, annealed, diameter 250 μm).

Exemplary embodiment 1c: silver brush

A brush is made from a soft annealed silver wire as follows:

Silver filaments are clamped tightly in one row in two clamping jaws, so that the filament length outside the clamping jaws is 30mm. The filaments consist of silver wire (supplier Goodfellow, 99.99%, annealed, diameter 125 μm).

Exemplary embodiment 1d: silver brush

A brush is made from a soft annealed silver wire as follows:

Silver filaments are clamped tightly in one row in two clamping jaws, so that the filament length outside the clamping jaws is 30mm. The filaments consist of silver wire (supplier Goodfellow, 99.99%, annealed, diameter 500 μm).

Embodiment 2: Antimicrobial titanium surface after silver brushing A pickled titanium sheet (TiAl6V4) was used as the substrate to be treated.

The brush from exemplary embodiment 1a was brought into contact with the substrate surface at a 45 ° angle in such a way that all filament ends located in a row were in contact with the surface. The angle between the bristle direction and the motion vector of the brush was 45 °. The bristle ends formed a straight line. This line was aligned parallel to the substrate surface and orthogonal to the motion vector of the brush. The contact pressure was set by positioning the bristle holder of the brush after contact of the bristle ends with the substrate by a further 5 mm in the direction of the substrate surface. The elastic deformation of the bristles took place here.

The brush was then passed over the surface 20 times at a speed of 40 m / min.

Silver particles were already visible under the light microscope. The particles had sizes (greatest distance between the edges in plan view) between 1 μm and 20 μm. The degree of surface coverage by measuring and counting the particles on 10 microscopic photographs according to measurement example 2 gave degrees of surface coverage between 0.02 and 0.2%.

The elemental composition of the surface was determined by means of XPS according to measurement example 1a). The silver concentration was 0.05 ± 0.02 at%.

The thicknesses of the particles were measured by way of example according to measurement example 4 and were between 200 nm and 2 μm (thickest point in each case evaluated). The measurement according to measurement example 5 using Staphylococcus epidermis demonstrated the antibacterial effect of the surface.

Exemplary embodiment 3: antimicrobial dispersion paint layer after silver brushing

An aluminum sheet treated with emulsion paint was used as the substrate to be treated. The aluminum sheet was coated with emulsion paint Brillux Superlux ELF 3000 white and the paint was dried in the oven for 4 hours at room temperature and 1 hour at 60 °.

The brush from embodiment 1a) was brought into contact with the substrate surface at a 45 ° angle in such a way that all filament ends in a row were in contact with the surface. The angle between the bristle direction and the motion vector of the brush was 45 °. The bristle ends formed a straight line. This line was aligned parallel to the substrate surface and orthogonal to the motion vector of the brush. The contact pressure was set by positioning the bristle holder of the brush after contact of the bristle ends with the substrate by a further 5 mm in the direction of the substrate surface. The elastic deformation of the bristles took place here.

The brush was then passed over the surface 20 times at a speed of 40 m / min.

Silver particles were already visible under the light microscope. The particles had sizes (greatest distance between the edges in plan view) between 1 μm and 15 μm. The degree of surface coverage by measuring and counting the particles on 10 microscopic photographs according to measurement example 2 gave degrees of surface coverage between 0.08 and 0.2%.

The elemental composition of the surface was determined by means of XPS according to measurement example 1a). The silver concentration was 0.08 ± 0.1 at%.

The measurement according to measurement example 5 using Melissococcus plutonius, pathogen of the European foulbrood, demonstrated the antibacterial effect of the surface.

Exemplary embodiment 4: Antimicrobial cardboard after silver brushing Black cardboard (Tetenal background cardboard Super Black, 150 g / m ² ) was used as the substrate to be treated.

The brush was then passed over the surface 20 times at a speed of 40 m / min.

Silver particles could be seen in the scanning electron microscope. The particles had sizes (greatest distance between the edges in plan view) between 0.4 μm and 10 μm. The degree of surface coverage by measuring and counting the particles on 10 microscopic photographs according to measurement example 3 gave degrees of surface coverage between 0.05 and 0.08%.

The elemental composition of the surface was determined by means of XPS according to measurement example 1a). The silver concentration was 0.03 ± 0.01 at%.

The thicknesses of the particles were measured by way of example according to measurement example 4 and were between 180 nm and 1.5 μm (thickest point in each case evaluated). The measurement according to measurement example 5 using Staphylococcus epidermis demonstrated the antibacterial effect of the surface.

Exemplary embodiment 5: antimicrobial titanium surface after copper brushes

A pickled titanium sheet (TiAl6V4) was used as the substrate to be treated.

The brush from embodiment 1b was brought into contact with the substrate surface at a 45 ° angle in such a way that all filament ends in a row were in contact with the surface. The angle between the bristle direction and the motion vector of the brush was 45 °. The bristle ends formed a straight line. This line was aligned parallel to the substrate surface and orthogonal to the motion vector of the brush. The contact pressure was set by positioning the bristle holder of the brush after contact of the bristle ends with the substrate by a further 5 mm in the direction of the substrate surface. The elastic deformation of the bristles took place here. The brush was then passed over the surface 20 times at a speed of 40 m / min.

Copper particles were already visible in the light microscope. The particles had sizes (greatest distance between the edges in plan view) between 2 μm and 22 μm. The degree of surface coverage by measuring and counting the particles on 10 microscopic photographs according to measurement example 2 gave degrees of surface coverage between 0.5 and 1%.

The elemental composition of the surface was determined by means of XPS according to measurement example 1a). The silver concentration was 0.49 ± 0.01 at%. The thicknesses of the particles were measured by way of example according to measurement example 4 and were between 200 nm and 2 μm (thickest point in each case evaluated).

The measurement according to measurement example 5 using Staphylococcus epidermis demonstrated the antibacterial effect of the surface.

Embodiment 6: Antimicrobial dispersion paint layer after copper brushing An aluminum sheet treated with dispersion paint was used as the substrate to be treated. The aluminum sheet was coated with emulsion paint Brillux Superlux ELF 3000 white and the paint was dried in the oven for 4 hours at room temperature and 1 hour at 60 °.

Copper particles were already visible in the light microscope. The particles had sizes (greatest distance between the edges in plan view) between 1 μm and 15 μm. The degree of surface coverage by measuring and counting the particles on 10 microscopic photographs according to measurement example 2 gave degrees of surface coverage between 0.05 and 0.15%.

The elemental composition of the surface was determined by means of XPS according to measurement example 1b). The copper concentration was 0.05 ± 0.01 at%. The thicknesses of the particles were measured by way of example according to measurement example 4 and were between 250 nm and 2.9 μm (thickest point in each case evaluated).

Exemplary embodiment 7: antimicrobial cardboard after copper brushes

Black cardboard (Tetenal background cardboard Super Black, 150g / m ² ) was used as the substrate to be treated.

Copper particles could be seen in the scanning electron microscope. The particles had sizes (greatest distance between the edges in plan view) between 0.3 μm and 10 μm. The degree of surface coverage by measuring and counting the particles on 10 microscopic photographs according to measurement example 2 gave degrees of surface coverage between 0.1 and 0.4%.

The elemental composition of the surface was determined by means of XPS according to measurement example 1b). The copper concentration was 0.14 ± 0.02 at%. The thicknesses of the particles were measured by way of example according to measurement example 4 and were between 220 nm and 2.5 μm (thickest point in each case evaluated).

The measurement according to measurement example 5 using Staphylococcus epidermis demonstrated the antibacterial effect of the surface. Exemplary embodiment 8: antimicrobial titanium surface after silver brushing (125um)

A ground titanium sheet (TiAl6V4) was used as the substrate to be treated.

The brush from embodiment 1c was brought into contact with the substrate surface at a 45 ° angle in such a way that all filament ends located in a row were in contact with the surface. The angle between the bristle direction and the motion vector of the brush was 45 °. The bristle ends formed a straight line. This line was aligned parallel to the substrate surface and orthogonal to the motion vector of the brush.

The contact pressure was set by positioning the bristle holder of the brush after contact of the bristle ends with the substrate by a further 5 mm in the direction of the substrate surface. The elastic deformation of the bristles took place here.

The brush was then passed over the surface 10 times at a speed of 40 m / min. The elemental composition of the surface was determined by means of XPS according to measurement example 1a). The silver concentration was 0.02 ± 0.01 at%.

Silver particles could be seen in the scanning electron microscope. The degree of surface coverage by measuring and counting the particles on 20 stochastically selected microscopic recordings according to measurement example 7 gave degrees of surface coverage between 0.07 and 0.4%. The arithmetic mean of the surface coverage was 0.22%.

The size of the particles (area in plan view) was between 0.0625 pm ² (resolution limit) and 65 pm ² . The average particle size was 0.38 pm ² . The particle density was 6405 particles / mm ² .

The measurement according to measurement example 6 using Escherichia coli demonstrated the antibacterial effect of the surface could be demonstrated.

Embodiment 9: antimicrobial titanium surface after silver brushing (250 μm)

A ground titanium sheet (TiAl6V4) was used as the substrate to be treated. The brush from exemplary embodiment 1a was brought into contact with the substrate surface at a 45 ° angle in such a way that all filament ends located in a row were in contact with the surface. The angle between the bristle direction and the motion vector of the brush was 45 °. The bristle ends formed a straight line. This line was aligned parallel to the substrate surface and orthogonally to the motion vector of the brush.

The brush was then passed over the surface 10 times at a speed of 40 m / min.

The elemental composition of the surface was determined by means of XPS according to measurement example 1a). The silver concentration was 0.09 ± 0.02 at%. Silver particles could be seen in the scanning electron microscope. The degree of surface coverage by measuring and counting the particles on 20 stochastically selected microscopic recordings according to measurement example 7 gave degrees of surface coverage between 0.16 and 1.01%. The arithmetic mean of the degrees of surface coverage was 0.54%.

The size of the particles (area in plan view) was between 0.0625 pm ² (resolution limit) and 46 pm ² . The average particle size was 0.40 pm ² . The particle density was 13295 particles / mm ² .

An improved antimicrobial effect of the surface compared to embodiment 8 could be demonstrated.

Exemplary embodiment 10: antimicrobial titanium surface after silver brushing (500 μm)

A ground titanium sheet (TiAl6V4) was used as the substrate to be treated. The brush from embodiment 1d was brought into contact with the substrate surface at a 45 ° angle in such a way that all filament ends located in a row were in contact with the surface. The angle between the bristle direction and the motion vector of the brush was 45 °. The bristle ends formed a straight line. This line was aligned parallel to the substrate surface and orthogonal to the motion vector of the brush.

The brush was then passed over the surface 10 times at a speed of 40 m / min.

The elemental composition of the surface was determined by means of XPS according to measurement example 1a). The silver concentration was 0.1 ± 0.02 at%.

Silver particles could be seen in the scanning electron microscope. The degree of surface coverage by measuring and counting the particles to 20 stochastically selected th microscopic recordings according to measurement example 7 showed degrees of surface coverage between 0.15 and 2.23%. The arithmetic mean of the degrees of surface coverage was 1.52%.

The size of the particles (area in plan view) was between 0.25 pm ² (resolution limit) and 480 pm ² . The average particle size was 2.7 pm ² . The particle density was 5766 particles / mm ² .

An improved antimicrobial effect compared to embodiment 9 could be demonstrated.

Embodiment 11: Silver coating of brushed titanium surfaces after aqueous ultrasonic cleaning

The Ilten titanium samples produced according to Examples 8, 9 and 10 were cleaned, rinsed and dried for 1 min in an ultrasonic bath filled with deionized water.

The samples were measured in a scanning electron microscope. Particles were visible in all cases. Analogously to embodiments 8, 9 and 10, the surfaces were characterized by measuring and counting the particles on 20 stochastically selected microscopic recordings according to measurement example 7. The following values resulted:

125 μm filaments (exemplary embodiment 8): degrees of surface coverage between 0.007% and 0.046%. The arithmetic mean of the surface coverage was 0.015%. The size of the particles (area in plan view) was between 0.0625 pm ² (dissolution limit) and 17 pm ² . The average particle size was 0.14 pm ² . The particle density was 1081 particles / mm ² .

250 μm filaments (exemplary embodiment 9): degrees of surface coverage between 0.004% and 0.153%. The arithmetic mean of the surface coverage was 0.046%. The size of the particles (area in plan view) was between 0.0625 pm ² (dissolution limit) and 15.9 pm ² . The average particle size was 0.21 pm ² . The particle density was 2205 particles / mm ² .

500 μm filaments (exemplary embodiment 10): degrees of surface coverage between 0.100% and 0.274%. The arithmetic mean of the surface coverage is carried 0.172%. The size of the particles (area in plan view) was between 0.25 gm ² (dissolution limit) and 48.25 gm ² . The average particle size was 0.92 gm ² . The particle density was 1892 particles / mm ² .

Claims

Patent claims:

1. Use of a silver filament-containing and / or copper filament-containing rubbing device to produce an antimicrobial surface or to improve the antimicrobial properties of a surface.

2. Use according to claim 1, wherein the generation of the antimicrobial surface or the improvement of the antimicrobial properties of the surface by transferring silver-containing and / or copper-containing particles which in plan view have a largest diameter of 2 to 15 μm and in section perpendicular to the axis of this largest diameter have a maximum thickness of 200 nm to 2 pm.

3. Use according to claim 2, wherein the aspect ratio V of the greatest diameter in plan view to the greatest thickness of the silver-containing and / or copper-containing particles 1000: 1> V> 1.2: 1, preferably 500: 1> V> 1.5: 1, more preferably 200: 1> V> 2: 1, more preferably 100: 1> V> 3: 1, more preferably 100: 1> V> 5: 1, more preferably 50: 1> V> 9: 1.

4. Use according to one of the preceding claims, wherein silver-containing and / or copper-containing particles are transferred to the surface in such a way that a surface coverage A of 5%>A> 0.01% is preferred ^{over an area of at least 0.25 mm 2} 2%>A> 0.02%, more preferably 1%>A> 0.03%, more preferably 0.5%>A> 0.04% results from the transferred particles.

5. Use according to one of the preceding claims, wherein silver-containing and / or copper-containing particles are transferred to the surface in such a way that a surface concentration c of 10 at%>c> 0.005 at% is preferred ^{on an area of at least 0.25 mm 2} 5 at%>c> 0.01 at%, more preferably 2 at%>c> 0.05 at%, more preferably 1 at%>c> 0.08 at% silver and / or copper results from the transferred particles, measured using XPS and based on the total number of atoms detected using XPS.

6. Use according to one of the preceding claims, wherein the silver-containing and / or copper-containing filaments of the friction device

a diameter of <2 mm and> 10 pm, preferably <1 mm and> 5 pm, more preferably <1 mm and> 150 pm, even more preferably <1 mm and> 200 pm and particularly preferably <800 and> 400 pm and / or

- a Vickers hardness of 25-200, preferably 40-100 and / or - have a nominal tensile strength of <600 MPa and> 10 MPa, preferably <500 MPa and> 50 MPa, more preferably <350 MPa and> 150 MPa and / or

7. Use according to any one of the preceding claims, wherein the treated

Surface comprises or consists of a material selected from the group consisting of paper, in particular wallpaper, cardboard, plastic, foils, lacquer, paint, plasma polymer coating, diamond and diamond-like coatings, metal, metallic coatings, ceramics, metal-oxide coatings, silicon-containing coatings tings, glass, especially frosted glass, concrete, stone, wood, fabric, fleece, knitted fabrics, woven fabrics, bones, horns, teeth, scales, skin and hair.

8. A method for producing an antimicrobial surface or for improving the antimicrobial properties of a surface, comprising the steps: a) providing a surface to be treated, preferably as defined in claim 7, b) providing a silver filament-containing and / or copper filament-containing rubbing device, preferably as in Claim 6 defines, c) coating the surface to be treated with the friction device, preferably so that silver-containing and / or copper-containing particles are transferred to the surface as defined in one of claims 2 to 5, with the proviso that if the friction device comprises copper-containing filaments, the surface to be treated provided is not a surface of an electrical steel sheet.

9. Article with at least partial antimicrobial surface, which is produced by a method according to claim 8, or article with at least partial antimicrobial surface, comprising silver-containing and / or copper-containing particles, as defined in one of claims 2 to 5, with the proviso that if the surface is a surface of an electrical steel sheet, silver-containing particles are also included.

10. The object according to claim 9, selected from the group consisting of beehive, wallpaper, medical product or part thereof, in particular implant, crockery, cutlery, door, handles, preferably door handles or handles of shopping carts, fittings, switches, Socket, cover, item of clothing, claw, hoof, fingernail, tooth, skin, fur, wall (in terms of architecture), window frame, window pane, floor covering, preferably laminate, parquet, linoleum, PVC, tile, tile, carpet, sanitary ware, beds ( Bed frames, bed boxes), chairs, tables, table tops, worktops (especially for kitchens), household appliances, mobile devices, keyboards, mice and mouse pads

11. Friction device, in particular brush, very particularly brush selected from the group consisting of plate brush, plate brush, strip brush, sword brush, cup brush, conical brush, roller brush, round brush and spiral brush, for a use according to one of claims 1 to 7 or a method according to claim 8 , with the proviso that the friction device comprises silver-containing filaments, preferably as defined in claim 6.

12. Friction device according to claim 11, wherein the filaments are aligned at an angle between 2 and 80 °, preferably between 10 and 70 °, more preferably between 25 and 60 ° and particularly preferably 45 ° to the surface normal of the filament holder, preferably the brush back.

13. Friction device according to claim 11 or 12 as part of a cleaning system, in particular as part of a vacuum cleaner, preferably as part of a vacuum cleaner with an actively moving brush head.