Coating with increased antibacterial properties

Abstract

A coated substrate (10), characterized in that it comprises an antibacterial coating (20) coated on the surface of the substrate (10) by sputter method.

Description

[0001] COATING WITH INCREASED ANTIBACTERIAL PROPERTIES

[0002] TECHNICAL FIELD

[0003] The invention relates to a coating designed with transparent and antibacterial properties, a product coated with this coating, and a production method thereof.

[0004] PRIOR ART

[0005] Antibacterial coatings are coatings applied to various surfaces, usually to prevent the growth of microorganisms. These coatings aim to provide a hygienic environment by preventing accumulation / colonization of bacteria, viruses, and other microorganisms on the surface. Furthermore, the multilayered nature of these coatings provides flexibility of use in a variety of applications. These properties are ideal for many different industries and applications, such as healthcare, automotive industries, and frequently contacted surfaces

[0006] As far as the state of the art known, same function is performed via various production methods. For example, Cu is used to enhance the effect in antibacterial coatings. It is stated that a SiC>2 layer is added under the layer that will have an antibacterial effect, in order to increase the adhesion of this layer to the surface. However, this usage will be mechanically weak as the antibacterial layer is left open to interferences from the surface.

[0007] Many efforts have been made in the literature to overcome this problem as much as possible. To ensure mechanical strength, a thick top layer of various ceramic materials is coated on top of the Cu layer. However, these layers cause the optical transmittance remaining below the desired level. And also, they prevent the antibacterial particles from reaching the surface, leading to a decrease in the desired antibacterial effect.

[0008] Antireflective (also referred to as AR in the text) and hydrophobic properties can be incorporated to the antibacterial structure with other layers. For AR, high and low refractive index materials can be used consecutively under the antibacterial layer. For hydrophobic properties, a fluorosilane-based layer can be formed on the top layer. The hydrophobic coating is also said to reduce the transfer of bacteria from the surface to human skin by 60%.

[0009] In prior art, antibacterial layers were attempted to be obtained with different alloyings, however, no information has been provided on chemical and mechanical strengths. In such structures, mechanical and chemical effects will reduce the antibacterial effect of the coating.

[0010] EP3938446A1 discloses a process for producing an antimicrobial coating on a glass substrate, an antimicrobial coated glass substrate prepared by the process, and the use thereof. Said coating is in the form of a solution, and comprises a solution containing silicon and particles in said solution.

[0011] As a result, all the above-mentioned problems have made it imperative to make an innovation in the relevant technical field.

[0012] BRIEF DESCRIPTION OF THE INVENTION

[0013] The present invention relates to an antibacterial coating, a process for applying said coating to a substrate, and a product on which said antibacterial coating is applied, designed to eliminate the aforementioned disadvantages and to bring new advantages to the relevant technical field.

[0014] The main object of the invention is to introduce an antibacterial coating with increased activity.

[0015] Another object of the invention is to introduce a transparent antibacterial coating with high light transmittance on the surfaces to which it is applied.

[0016] Another object of the invention is to introduce an antibacterial coating that does not create an iridescence effect on the surface to which it is applied.

[0017] Another object of the invention is to introduce a heat treatable antibacterial coating. To achieve all the objects mentioned above and that will emerge from the following detailed description, the present invention is a coated substrate. Accordingly, said invention is characterized in that it comprises an antibacterial coating coated on the surface of the substrate by sputter method.

[0018] A preferred embodiment of the invention is that said antibacterial coating comprises a conductive layer.

[0019] Another preferred embodiment of the invention is that said conductive layer comprises at least one or a combination of more than one of the elements Cu, Ag, Sn, Pd, Pt, Au, Al, In, Ga, Nb, Mo, Zn, Zr, Ti, Si, Sb, W.

[0020] Another preferred embodiment of the invention is that said conductive layer is in the form of at least one of the metal, oxide, metal oxide, nitride, or oxynitride forms.

[0021] Another preferred embodiment of the invention is that the conductive layer contains a plurality of nanoparticles.

[0022] Another preferred embodiment of the invention is that it comprises a plurality of nanoparticles positioned on said conductive layer.

[0023] Another preferred embodiment of the invention is that said nanoparticles are agglomerated in nanoscale on the conductive layer.

[0024] Another preferred embodiment of the invention is that said nanoparticles comprise at least one or a combination of more than one of the elements Cu, Ag, Sn, Pd, Pt, Au, Al, In, Ga, Nb, Mo, Zn, Zr, Ti, Si, Sb, W.

[0025] Another preferred embodiment of the invention is that it comprises Cu as said nanoparticle.

[0026] Another preferred embodiment of the invention is that it comprises Cu and Ag together as said nanoparticle. Another preferred embodiment of the invention is that said conductive layer comprises at least one of Nb, Ti, Sn, or In.

[0027] Another preferred embodiment of the invention is that said antibacterial coating comprises an optional bottom layer positioned between the substrate and the conductive layer.

[0028] In another preferred embodiment of the invention, the bottom layer preferably comprises at least one or more of the materials SixNy, SiOxNy, ZnAIOxZnSnOx, TiOx, TiNx, ZrNx, TiNbOx, NbZrOx, TiZrOx, NbNx.

[0029] BRIEF DESCRIPTION OF THE DRAWING

[0030] Fig. 1 shows the SEM image of soda lime glass, which is coated with ITO / Cu respectively and has antibacterial properties.

[0031] Fig. 2 shows the SEM image of soda lime glass, which is coated with ITO / Cu+Ag respectively and has antibacterial properties.

[0032] Fig. 3 shows a representative view of the coated product.

[0033] LIST OF REFERENCES

[0034] 10 Substrate

[0035] 20 Antibacterial coating

[0036] 210 Bottom layer

[0037] 220 Conductive layer

[0038] 230 Nanoparticle

[0039] DETAILED DESCRIPTION OF THE INVENTION

[0040] In this detailed description, the antibacterial coating (20) of the invention is explained by way of example only for a better understanding of the subject, which shall not create any limiting effect. Agents that prevent the formation of bacteria on surfaces are called "antibacterial", agents that prevent the formation of viruses are called "antiviral", and agents that prevent the formation of fungi are called "antifungal". Antibacterial surfaces are surfaces that prevent the formation of bacteria, viruses and mold / fungus altogether. Bacteria, viruses, and fungi differ from each other mainly in terms of physical size, structural complexity, as well as genetic material, metabolic activity, and colonization.

[0041] Standard tests are the tools that apply the reproduction and development of microbial entities according to a specific procedures and as a result, enable the interpretation of the development of these entities. Antibacterial, antivirus, and antifungal tests are among the tests applied to the coated transparent surfaces. In general, the most common tests are: ISO 13125 (antifungal), ISO 27447 (antibacterial), ISO 18061 (antiviral), ISO 22196 (antibacterial), ISO 27447 (antibacterial), ASTM-E1053 (antiviral), and JIS Z 2801 (antibacterial) tests.

[0042] The coatings developed within the scope of the invention were evaluated according to ISO 22196 test. ISO 22196 "Measurement of antibacterial activity on plastics and other non-porous surfaces" specifies a method of evaluating the antibacterial activity of antibacterial-treated plastics and other non-porous, surfaces of products (including intermediate products). It is not intended to be used to evaluate the effects and propagation of bacteria on non-porous surfaces without antibacterial treatments. The bacteria used are Staphylococcus aureus. Antibacterial activity is expressed logarithmically.

[0043] The antibacterial coating (20) designed within the scope of the invention may be applied on a substrate (10). Herein, said substrate (10) may be opaque, transparent, organicbased, or glass substrate (10). The "+" sign in the text of the invention indicates the combined use of the elements before and after it.

[0044] The present invention relates to a coating comprising at least one thin film having high optical transmittance and permanent antibacterial effect, and to the application of such coating on a substrate (10) using physical vapor deposition (hereinafter also referred to as sputter in the text) method. In the embodiment of the invention, an antibacterial coating (20) comprising at least one thin film is positioned on the substrate (10). In an embodiment of the invention, said antibacterial coating (20) comprises:

[0045] • an optionally available bottom layer (210) comprising at least one layer;

[0046] • a conductive layer (220) comprising at least one thin film, positioned on the bottom layer (210) in case said bottom layer (210) is used, or on the substrate (10) in case bottom layer (210) is not used;

[0047] • a plurality of nanoparticles (230) which may contain one or more elements positioned on or embedded in said conductive layer (220).

[0048] The bottom layer (210) optionally positioned on the substrate (10) may be in the form of metal, oxide, oxynitride, nitride. Said bottom layer (210) preferably comprises at least one or more of the materials SixNy, SiOxNy, ZnAIOxZnSnOx, TiOx, TiNx, ZrNx, TiNbOx, NbZrOx, TiZrOx, NbNx. The use of the lower layer (210) contributes to increasing the heat treatment resistance of the antibacterial coating (20). Furthermore, the bottom layer (210) contributes to reducing reflection in the antibacterial coating (20). In addition, the bottom layer (210) contributes to improve the adhesion of the antibacterial coating (20) to the substrate (10).

[0049] In a preferred embodiment, SiNxis used as the bottom layer (210). Thus, if soda lime glass (hereinafter referred to as glass) is preferred as the substrate (10), alkaline ion migration between the glass and the antibacterial coating (20) is reduced. In another preferred embodiment, TiOxis preferred as bottom layer (210). In this way, if glass is similarly preferred as the substrate (10), in addition to reducing alkali ion migration, it can also contribute to the antibacterial properties of the antibacterial coating (20).

[0050] The conductive layer (220) positioned on the substrate (10) or, in the event that a bottom layer (210) is used, on the bottom layer (210) comprises at least one or a combination of more than one of the elements Cu, Ag, Sn, Pt, Au, Al, In, Ga, Nb, Mo, Zn, Zr, Ti, Si, Sb, W. These elements are used in the form of at least one of the forms of metal, oxide, metal oxide, nitride, oxynitride. Preferably the conductive layer (220) is used in the form of metal oxide. In an alternative embodiment, however, the conductive layer (220) preferably contains metal. In another embodiment, however, the conductive layer (220) preferably comprises metal oxynitride. In the embodiment of the invention, nanoparticle (230) formation takes place on the conductive layer (220) and / or during the coating of the conductive layer (220). These nanoparticles (230) are used to provide antibacterial properties.

[0051] In an alternative embodiment of the invention, the antibacterial coating (20) is provided as a single layer. In this embodiment, aforementioned bottom layer (210), conductive layer (220), and nanoparticle (230) are coated simultaneously to form a single layer, not on top of each other.

[0052] Within the scope of the invention, various studies were carried out to incorporate antibacterial properties to the substrate (10). The studies carried out within this context were tested with coating processes in a way that covers all and / or at least part of the surface of the substrate (10). In the preferred embodiment, the sputter method is used. In the non-limiting example of the invention, glass is used as the substrate (10).

[0053] As is known in the sputter technique, when very thin theoretical film thicknesses are involved, there are cases where the coverage is low. This is currently considered a disadvantage, but within the scope of the study, of the invention is used as an advantage in. As is known in the art, although it varies for each material, the coverage of the coated layer remains limited until it reaches a certain thickness. This can be further adjusted by coating parameters and ambient conditions.

[0054] Within the scope of the invention but not limited to, metal-containing layers of theoretical thicknesses of unfully surface coverage are processed and subsequently heat-treated as a secondary step at a temperature between 400 °C and 700 °C for 4 to 20 minutes. With the given heat energy, nanoscale agglomeration of metal materials with low coverage on the surface is obtained and in this way, a plurality of nanoparticles (230) are obtained on the surface of the substrate (10). Nanoparticles (230) comprise at least one or a combination of more than one of the elements of Cu, Ag, Pd, Sn, Pt, Au, Al, In, Ga, Nb, Mo, Zn, Zr, Ti, Si, Sb, W. In the preferred embodiment, the nanoparticles (230) comprise the elements Cu (copper) and / or Ag (silver).

[0055] Within the scope of the invention, 2-dimensional growth is defined as the film thickening in a continuous manner in 2 axes parallel to the surface of the substrate (10) and along another axis, which is parallel to the surface normal of the substrate (10) to which the antibacterial coating (20) will be applied, The film thickening along the surface of the substrate (10) in the axes parallel to the surface of the substrate (10) in a discontinuous manner and along another axis, which is an axis parallel to the surface normal of the substrate (10) surface, is defined as 3-dimensional growth. Referring to Figure 1 and Figure 2, the obtained nanoparticles (230), although slightly different in size and geometry, grow in 3 dimensions on the nanometric scale. Since aforementioned heat treatment is carried out under atmospheric conditions, said nanoparticles (230) contain metal and / or metal oxides, although pure metal starting materials are used in a vacuum environment.

[0056] Alternative applications can also be used during and / or after sputter application to obtain Cu and Ag nanoparticles (230). One of the alternative applications is to add Cu, Cu+Ag, Ag to the content of the starting material to be used to obtain the conductive layer (220), which will show said antibacterial properties, or these materials can be deposited together on the surface of the substrate (10) by simultaneous sputter (known in the art as co-sputter) method. In this way, the conductive layer (220) and the nanoparticles (230) mentioned in the content can be deposited on the substrate (10) in a single step. Another alternative application is coating a conductive layer (220) on the surface of the substrate (10) and then coating nanoparticles (230) on top.

[0057] In the preferred technique, in order to obtain nanoparticles (230) of the desired size in a vacuum environment, said Cu and Ag containing nanoparticles (230) can be subjected to heat treatment before, during and / or after the sputter process, methods like flash lamp application, ion beam assistance, laser annealing can be applied.

[0058] In this invention, a multilayer transparent thin film structure is proposed to enhance the antibacterial effect compared to the prior art. Light transmission is kept at maximum level via conductive layer (220) within in this multilayer structure, and antibacterial activity is increased at the same time. The main advantages of the invention are listed below.

[0059] • The main advantage of the embodiments within the scope of the invention is to obtain a coating with a higher antibacterial effect performance.

[0060] • The antibacterial coatings (20) within the scope of the invention are optically transparent in addition to their superior antibacterial properties. It is already known that the use of Cu and Ag on the glass used as substrate (10) shows antibacterial properties. In the studies carried out within this context, Cam / Cu and Cam / Cu+Ag combinations were taken as reference. Measurements show that usage of conductive layer (220) in contact with the glass as substrate (10) further enhances the antibacterial properties provided by the single use of Cu or Cu+Ag combination on the glass as substrate (10). Transparent conductive oxides may be preferred as conductive layer (220). In the described embodiments of the invention, Nb:TiC>2 (Niobium: Titanium oxide) or ITO (Indium Tin Oxide) is preferred as said conductive layer (220).

[0061] Within the scope of the invention, antibacterial activity can be demonstrated more clearly with comparative examples of the application consisting of layers coated on top of each other. These structures are shown in Table-1 .

[0062] Nanoparticle

[0063] Conductive laye

[0064] Table 1 : 6 sample structures produced within the scope of antibacterial coating (20) development

[0065] The samples given in Table 1 were produced using the sputter method.

[0066] The first coating is of Glass / Cu structure. Nanoparticles (230) were produced to determine the antibacterial properties of Cu material.

[0067] The second coating has a Glass / Nb:TiC>2 / Cu structure. In this structure, a comparison was made with different conductive layer (220).

[0068] The third coating has Glass / ITO / Cu structure and level of change for antibacterial effect was observed via ITO layer, conductive layer (220) which is after the glass in this structure. The fourth coating has a Glass / Cu+Ag structure and was produced to observe how the antibacterial effect of Ag material as nanoparticle (230) changes after interaction with Cu material as nanoparticle (230).

[0069] The fifth coating has a Glass / Nb:TiO2 / Cu+Ag structure. In this structure, the Cu+Ag combination as nanoparticles (230) was compared with a different transparent conductive layer (220).

[0070] The sixth coating has Glass / ITO / Cu+Ag structure. In this Cu+Ag combination as nanoparticles (230), level of change for antibacterial effect was observed to what extent the via ITO layer, which comes as the conductive layer (220). The sixth structure also showed a much higher antibacterial effect compared to other references.

[0071] The antibacterial tests of the samples were performed with S. Aureus bacteria in accordance with the ISO22196 standard. The results are given in Table 2.

[0072] Table 2: Anti-bacterial test results

[0073] Two groups of studies were carried out, in the first group, Nb:TiC>2 or ITO was used as the conductive layer (220) between the glass used as substrate (10) and Cu as nanoparticle (230), and in the second group, Nb:Ti02or ITO was used as the conductive layer (220) between the glass used as substrate (10) and Cu+Ag combination as nanoparticle (230). In the first group of applications, the antibacterial activity increased from 20% to 70% when Nb:TiC>2 was used as a conductive layer (220) between the glass as a substrate (10) and Cu as nanoparticle (230), compared to the application of Cu as nanoparticle (230) on the reference glass. It was increased from 20% to 99.52% when ITO was used as a conductive layer (220) between the glass and Cu as nanoparticles (230), compared to the application of Cu as a nanoparticle (230) on the reference glass.

[0074] In the second group of applications, the antibacterial activity increased from 70% to 81% when Nb:TiO2 was used as a conductive layer (220) between the glass and Cu+Ag as nanoparticle (230) compared to the application of Cu+Ag as nanoparticle (230) on reference glass. It increased from 70% to 99.999% when ITO was used as the conductive layer (220) between the glass and Cu+Ag as nanoparticle layer (230) compared to the application of Cu+Ag as nanoparticle (230) on reference glass.

[0075] As described above, the use of nanoparticles (230) dispersed on or in the conductive layer (220) has been observed to enhance antibacterial activity. The nanoparticle (230), when positioned on the conductive layer (220), was observed to enhance the antibacterial activity. The nanoparticle (230), when used dispersed in the conductive layer (220), was observed to enhance the antibacterial activity.

[0076] The scope of protection of the invention is specified in the appended claims and cannot be limited to what is described for illustrative purposes in this detailed description. It is clear that a person skilled in the art can produce similar embodiments in the light of what is explained above, without deviating from the main theme of the invention.

Claims

CLAIMS1. A coated substrate (10), characterized in that it comprises an antibacterial coating (20) coated on the surface of the substrate (10) by sputter method.

2. The coated substrate (10) according to claim 1 , characterized in that said antibacterial coating (20) comprises a conductive layer (220).

3. The coated substrate (10) according to claim 2, characterized in that said conductive layer (220) comprises at least one or a combination of more than one of the elements Cu, Ag, Sn, Pd, Pt, Au, Al, In, Ga, Nb, Mo, Zn, Zr, Ti, Si, Sb, W.

4. The coated substrate (10) according to claim 2, characterized in that said conductive layer (220) is in the form of at least one of the metal, oxide, metal oxide, nitride, or oxynitride forms.

5. The coated substrate (10) according to claim 2, characterized in that the conductive layer (220) contains a plurality of nanoparticles (230).

6. The coated substrate (10) according to claim 2, characterized in that it comprises a plurality of nanoparticles (230) positioned on said conductive layer (220).

7. The coated substrate (10) according to claim 5 or 6, characterized in that said nanoparticles (230) on the conductive layer (220) are agglomerated in nanometer scale.

8. The coated substrate (10) according to claim 5 or 6, characterized in that said nanoparticles (230) comprise at least one or a combination of more than one of the elements Cu, Ag, Sn, Pd, Pt, Au, Al, In, Ga, Nb, Mo, Zn, Zr, Ti, Si, Sb, W.

9. The coated substrate (10) according to claim 5 or 6, characterized in that it comprises Cu as said nanoparticle (230).

10. The coated substrate (10) according to claim 5 or 6, characterized in that it comprises Cu and Ag together as said nanoparticle (230).11 . The coated substrate (10) according to claim 3, characterized in that said conductive layer (220) comprises at least one of Nb, Ti, Sn, or In.

12. The coated substrate (10) according to claim 1 , characterized in that said antibacterial coating (20) comprises an optional bottom layer (210) positioned between the substrate (10) and the conductive layer (220).

13. The coated substrate (10) according to claim 12, characterized in that the bottom layer (210) preferably comprises at least one or more of the materials SixNy, SiOxNy. ZnAIOxZnSnOx, TiOx, TiNx, ZrNx, TiNbOx, NbZrOx, TiZrOx, NbNx.

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