Antimicrobial and antiviral coating

The present invention provides a process for producing antibacterial and/or antiviral coatings on glass substrates, antibacterial and/or antiviral coated glass substrates, and the use of such antibacterial and/or antiviral coatings in a diverse range of applications. Concerning the use of coated glass substrates.

Additionally, the present invention provides a process for producing a toughened antimicrobial and/or antiviral coating on a glass substrate, a toughened antimicrobial and/or antiviral coated glass substrate, and methods for such a process in a diverse range of applications. Concerning the use of toughened antibacterial and/or antiviral coated glass substrates.

Thus, the present invention relates to a process for producing an antibacterial and/or antiviral coating on a glass substrate, and a glass substrate having such an antibacterial and/or antiviral coating on at least one surface thereof. The present invention also includes antimicrobial coated glass substrates made in accordance with the present invention, such as, but not limited to, architectural and automotive glazing, splashbacks, furniture, bottles, wall coverings, and touch screens. It also relates to antibacterial and/or antiviral articles.

As the frequency of use of electronic devices spreads around the world, the presence of microorganisms that may be present on the surfaces of such substrates also increases, thus increasing the potential transfer of microorganisms between individuals. Indeed, with touchscreens placed in stores and supermarkets, for example, hundreds of people per hour may use touchscreen terminals, and therefore microorganisms, which can be bacteria, fungi, yeasts, viruses, can be spread between users. there is a possibility. For the purposes of this invention, viruses are also considered to be microorganisms.

Additionally, as the threat of resistance to certain bacterial strains increases and epidemics emerge from the transmission of several viruses, individual glass substrates, regardless of the device or application, have the potential to prevent the spread of microorganisms, especially bacteria and viruses. There is an increasing need to be able to stop the

It has long been known that microorganisms, including bacteria, yeast, and viruses, can be killed when they come into contact with metal surfaces. Indeed, copper has been used on surfaces such as door handles, bathroom fixtures and beds in an attempt to stop the spread of microorganisms in hospital environments (Applied and Environmental microbiology 2011, March, 77(5), 1541-1547 ).

However, the skill of incorporating anti-bacterial and anti-viral properties into surfaces such as windows and doors, where the transparency must be maintained to the required standards and preferably also resistant to abrasion and scratches, for example, can be difficult. It has been proven. This not only makes it difficult to impart durable antibacterial and antiviral activity to glass substrates, but also that any coating applied to glass substrates that provides antibacterial and antiviral activity can be difficult to achieve while maintaining aesthetic appearance at an acceptable cost. This is because necessary parameters for glazing must also be provided. Additionally, glass substrates, particularly windows and doors, are preferably heat treated or annealed in order to comply with current glazing standards, so that they meet the performance requirements in that they are strengthened after application of the coating; Providing glazing products that are capable of providing additional antibacterial and antiviral properties is, of course, a challenge for glass manufacturers.

Attempts have been made to impart antibacterial activity to substrate surfaces. For example, WO 2009/098655 describes a method for imparting antimicrobial properties to a substrate, which involves coating the substrate with a silver film by radiofrequency sputtering. However, this document does not mention the characteristics of the glass substrate after treatment, especially after heat treatment.

Korean Published Patent No. 2013-0077630 discloses a dispersion of nanometal ions in silica sol-gel for anti-fingerprint and antibacterial purposes. However, copper particles are not considered, and instead the focus is on the generation of nanometal ions through strong metal salt reactions, especially silver. Similarly, China Patent No. 109534687 describes a process for providing a silica-based sol-gel with incorporated metal ions, preferably silver, used to provide antibacterial functionality. There is.

US Pat. No. 9,028,962 discloses a complex multi-step process in which copper oxide particles are applied to a transparent substrate. The glass substrate is subjected to ion exchange before or after particle application to chemically strengthen the glass, followed by reduction of the copper oxide particles. The antimicrobial glass is further coated with a fluorosilane layer.

In WO 2005/115151, the surface of the particles is modified by the attachment of a functional silane, i.e. a dispersion aid and/or adhesion promoter formed of oligomers with a high content of OH groups, containing nanoparticle additives. A functional sol-gel coating is disclosed that is said to have both antimicrobial and decorative functions as a result of the antibacterial and decorative functions.

US Patent Application Publication No. 2010/0015193 discloses a substrate having a plurality of antimicrobial metal islands formed on the surface of the substrate and exposed to the external atmosphere for the purpose of forming a resistant coating. The average contact angle value between the substrate and each antimicrobial metal island is less than 90 degrees as measured by scanning electron microscopy. The antimicrobial metal islands are placed by sputtering in an inert gas atmosphere.

German Utility Model No. 202005006784 generally relates to doors, windows and/or linings of air conditioners or refrigerators, which are proposed to be coated at least in part on their surfaces with a transparent, porous sol-gel layer. describe an article such as, in which the sol-gel layer comprises an organically modified siloxane matrix having one or more alkyl groups and doped with at least one substance/compound with antimicrobial effect. Unfortunately, no antimicrobial test data are provided in support.

However, none of the above-mentioned prior art documents details the process according to the invention, and the process according to the invention can be used at a reasonable cost in the glass industry on substrates, e.g. glass or glazing. Provides antimicrobial coatings with the necessary microbial and/or viral resistance and optical properties, as well as resistance to abrasion and scratches, to the required level for glass substrates and glazings that may be used in locations with frequent public contact. It is possible to do so.

Additionally, none of the above documents address the problems encountered when attempting to bring antibacterial and/or antiviral coatings to glass substrates on an industrial scale, or in fact apply them to glass substrates during industrial coating operations and their completion. does not address how to ensure that antimicrobial and antiviral coatings applied provide the same performance as antimicrobial and/or antiviral coatings applied to glass substrates at the beginning of industrial coating operations. The above documents do not mention the conditions necessary to provide stability both to the active ingredient and to the antibacterial and/or antiviral coating obtained after application to the glass substrate. Moreover, the above-mentioned documents are silent regarding the problems associated with maintaining the reproducibility of antibacterial and/or antiviral coatings on glass substrates produced on an industrial scale. This is the problem that the present invention seeks to address.

Therefore, glass substrates provided with transparent coatings are capable of reducing the growth and transmission of microbial pathogens, especially bacteria and viruses, while maintaining optical performance and mechanical durability at a reasonable cost and industrial scale. There is a need for

Antibacterial and/or antiviral coated glass substrates made in accordance with the present invention can be used, for example, in automotive glazing and architectural glass windows, including commercial and residential applications, and food and healthcare applications, including but not limited to. The present invention also applies to applications such as touch screens, mobile phones, laptop computers, book readers, video game devices, automatic teller machines, screens, medical containers, refrigeration applications, or during or in transit applications and modes of transport. It may also find application in, but not limited to, electronic devices. In fact, the invention is applicable to any application or situation where a glass substrate is used and can be touched or where information displayed on a glass screen is retrieved by touch.

Additionally, antibacterial and/or antiviral coatings made in accordance with the present invention can be applied to e.g. coated and uncoated substrates, e.g. It can be used with glass substrates such as, but not limited to, coated float glass using chemical vapor deposition (CVD) and/or physical vapor deposition (PVD) to produce the coating layer that is disposed.

Furthermore, when the antibacterial and/or antiviral coating made according to the invention is applied to a glass substrate, the glass substrate may comprise flat glass, e.g. float glass, or the glass substrate may comprise e.g. borosilicate glass. Alternative forms of glass may be included, such as, but not limited to, rolled plate glass, ceramic glass, tempered glass, chemically strengthened glass, hollow glass, or glass shaped for articles such as bottles, jars, and medical containers. .

<p>According to a first aspect of the invention, a process for producing an antimicrobial and/or antiviral coating on a substrate, the process comprising: (i) providing a glass substrate having a first surface and a second surface; (ii) providing a silicon-containing solution and a copper-containing particle solution or powder; and (iii) mixing together the silicon-containing solution and the copper-containing particle solution or powder in the presence of water and a hydrolyzable material. , forming a silica and copper coating composition, wherein the hydrolyzed material is (a) one or more polyols, (b) one or more weak acids having a pKa value of at least 0.5, or (c) one or more weak acids having a pKa value of at least 0.5. one or more polyols and one or more weak acids; (iv) contacting at least the first surface of the glass substrate with a silica and copper coating composition to deposit a layer of silica on the glass substrate; and (iv) curing the silica and copper coating composition deposited on the glass substrate to form a silica matrix coating layer, the copper-containing particles comprising silica in an amount of 1 to 50% by weight. deposited on the matrix coating layer and/or embedded within the silica matrix coating layer.</p><p>Additionally, in the context of the present invention, the process may further comprise the step of (v) strengthening the coated glass substrate at a temperature of at least 600°C, more preferably at a temperature of at least 650°C.</p><p>Preferably, the copper-containing particle solution or powder may contain copper-containing particles in the form of clusters of microparticles, nanoparticles of copper, copper alloys, copper metal or copper oxide or mixtures thereof.</p><p>That is, we believe that copper particles, when mixed with a silicon-containing solution and cured to form a silica matrix coating layer, provide effective antibacterial and/or antiviral properties to glass substrates. We have found it particularly compatible and useful. Indeed, in the context of the present invention, the inventors have demonstrated that the glass coating produced according to the present invention is effective antibacterial and/or antiviral, both before and after toughening at temperatures of at least 600 °C. We confirmed that it is possible to provide these characteristics.</p><p>The copper-containing microparticles or clusters of copper nanoparticles include a size range of 50nm to 15μm. More preferably, the copper particles are preferably provided in a size range of 75nm to 12μm. However, most preferably the copper particles are in the size range of 100nm to 10μm.</p><p>In the context of the present invention, when a copper alloy is present, it may contain one or more elements selected from zinc, tin, aluminum, silicon, nickel, manganese, beryllium, lead, iron, aluminum.</p><p>In the method for producing an antibacterial or antiviral coating on a glass substrate according to the first aspect of the invention, the hydrolyzed material comprises (a) one or more diols, (b) 1 having a pKa value of at least 0.5. (c) one or more diols and one or more weak acids. That is, with respect to the present invention, the inventors have demonstrated that the materials used to hydrolyze silicon to deposit a coating of silica on a glass substrate affect the antibacterial and antiviral properties of the coated glass substrate. I discovered giving.</p><p>When the hydrolyzable material is a polyol, the polyol is preferably selected from propylene glycol, ethylene glycol, 1,3-propanediol, 1,4-butanediol or glycerol.</p><p>Preferably the hydrolyzable material is a diol. Most preferably, propylene glycol is used as the hydrolysis material associated with the process of the present invention.</p><p>When the hydrolyzable material is a weak acid, i.e. an acid with a pKa value of at least 0.5, the weak acid is preferably one or more of oxalic acid, phosphoric acid, chloroacetic acid, citric acid, lactic acid, ascorbic acid, and propionic acid. selected from the group containing. Most preferably, however, we have found citric acid to be the preferred diol for use in connection with the present invention.</p><p>Copper-containing particle solutions or powders may include additional metal components such as, for example, lead, tin, iron, antimony, nickel, zinc, cadmium, chromium, arsenic, and tellurium. However, the additional metal components are preferably each present at low levels. For example, if present, the additional metal component constitutes less than 10% by weight of the silica matrix coating layer, more preferably less than 5% by weight of the silica matrix coating layer, or less than 1% by weight of the silica matrix coating layer.</p><p>Preferably, the silica and copper coating composition applied to the glass substrate according to the invention contains at least 1% by weight copper. Alternatively, the silica and copper coating composition applied to the glass substrate may contain 1-10% by weight copper. Alternatively, the silica and copper coating composition applied to the substrate may contain up to 50% copper by weight.</p><p>That is, the silica and copper coating composition deposited on the glass substrate, and thus the silica matrix coating layer so formed on the substrate, may contain from 1 to 50% by weight copper. Alternatively, the silica matrix coating layer so formed on the substrate may contain 2% to 40% copper by weight. Alternatively, the silica matrix coating layer so formed on the substrate may contain 5% to 25% copper by weight. Alternatively, the silica matrix coating layer so formed on the substrate may contain 10% to 25% copper by weight.</p><p>Alternatively, the silica and copper coating composition deposited on the glass substrate, and thus the silica matrix coating layer so formed on the substrate, may contain from 1 to 40% by weight copper. More preferably, the silica matrix coating layer so formed on the substrate may contain from 1% to 25% by weight copper. Most preferably, the silica matrix coating layer so formed on the substrate may contain from 1% to 20% copper by weight.</p><p>Preferably, the copper in the silica matrix coating layer is in the form of metallic copper, copper(I) oxide or copper(II) oxide. More preferably, the copper in the silica matrix coating layer is in the form of metallic copper or copper(I) oxide. However, most preferably the copper is in the form of copper metal.</p><p>Regarding the first aspect of the invention, the silicon-containing solution and the copper particle-containing solution or powder each preferably contain a solvent. The solvents used in the silicon-containing solution and the copper particle-containing solution or powder may be the same or different. The solvent is preferably selected from the group comprising, for example, diacetone alcohol, 1-methoxy 2-propanol (PGME), propylene glycol methyl ether (PGME), isopropanol, 3-methoxy-1-butanol and mixtures thereof. .</p><p>Preferably, the silica coating composition applied to a glass substrate according to the invention comprises at least 50% by weight silica. Alternatively, a silica coating composition applied to a glass substrate can include at least 65% silica by weight. Alternatively, the silica coating composition applied to the substrate comprises at least 75% by weight silica.</p><p>That is, the silica coating composition deposited on the glass substrate, and thus the silica matrix coating layer so formed on the substrate, may contain from 50% to 99% by weight silica. More preferably, the silica matrix coating layer so formed on the substrate may contain from 65% to 98% by weight silica. Alternatively, the silica matrix coating layer so formed on the substrate may contain 50% to 80% silica by weight. Alternatively, the silica matrix coating layer so formed on the substrate may contain 50% to 90% silica by weight.</p><p>The silica matrix coating layer made according to the invention is preferably tetraethyl orthosilicate, Si(OC₂H₅)₄, (TEOS) and/or its derivatives, which are hydrolyzed under mild reaction conditions to form transparent coatings. Silica matrix coating layers based on tetraethyl orthosilicate are ideal for use on glass substrates such as float glass. Furthermore, we have found that tetraethyl orthosilicate is preferably used in combination with a copper-containing particle solution or powder to form a silica matrix coating layer, and that this can be used in the absence of a coated glass substrate. It was found that superior results were obtained in terms of both antibacterial and antiviral reduction compared to .</p><p>In one embodiment of the process according to the invention, the silica and copper coating composition can be applied directly in contact with the glass substrate. Alternatively, the silica and copper coating composition can be applied on top of another layer deposited on a glass substrate.</p><p>Additionally, the silica and copper coating composition may further include zirconium. The amount of zirconium in the silica and copper coating composition is preferably set to the required amount of zirconium in the silica matrix coating layer. More preferably, the amount of zirconium in the silica coating composition is set relative to the required amount of zirconium in the silica matrix coating composition once cured.</p><p>For example, the silica coating composition can further include at least 1% by weight zirconium. Alternatively, the silica coating composition may include less than 1% by weight zirconium. In an alternative embodiment of the invention, the silica and copper coating composition may include 1-15% by weight zirconium. Preferably, the silica coating composition may contain 2-10% by weight zirconium. To improve the durability of the silica matrix coating layer, the silica and copper coating composition preferably contains 2-8% by weight of zirconium.</p><p>Zirconium is preferably present in the silica coating composition in the form of an oxide of zirconium.</p><p>For the process according to the invention, the silica coating composition preferably comprises one or more of spray coating, hydraulic atomization atomization, air atomization atomization, ultrasonic atomization, dip coating, spin coating, curtain coating or slot die coating. It can be applied to the glass substrate by means of. Most preferably, in the process according to the invention, the silica coating composition is applied to the glass substrate by roller coating or spray coating.</p><p>When following the process according to the invention, the surface of the glass substrate can be cleaned before applying the silica and copper coating composition to improve the quality of the coating. Cleaning the glass substrate may preferably include one or more of polishing with ceria, cleaning with an aqueous alkaline solution, rinsing with deionized water, and/or plasma treatment. Cleaning preferably removes any unwanted dust or dirt particles that may accumulate prior to application of the silica layer.</p><p>Curing of the silica and copper coating compositions may preferably be carried out by heating to a temperature in the range of 90°C to 450°C. More preferably, the method according to the invention may comprise curing the silica coating composition, preferably by heating to a temperature in the range of 90°C to 350°C. More preferably, the method according to the invention may comprise curing the silica coating composition, preferably by heating to a temperature in the range of 150°C to 350°C. Most preferably, the method according to the invention may comprise curing the silica coating composition, preferably by heating to a temperature in the range from 180°C to 300°C, or from 180°C to 250°C. . Curing the silica and copper coating composition is advantageous because it can improve the density of the silica matrix coating layer and the rate at which the silica matrix coating layer is formed.</p><p>Preferably, the silica matrix coating layer is deposited to a thickness in the range of 5 nm to 250 nm. Alternatively, the silica matrix coating layer is deposited to a thickness ranging from 5nm to 200nm. More preferably, the silica matrix coating layer is deposited to a thickness in the range of 10 to 100 nm, or the silica matrix coating layer may be deposited to a thickness in the range of 20 to 80 nm. Furthermore, the silica matrix coating layer may be deposited to a thickness in the range of 25-60 nm, or even 30-50 nm.</p><p>Copper-containing silica matrix coating layers can also be applied to glass substrates, for example by chemical vapor deposition and/or physical vapor deposition, and can be used in combination with coatings applied either above or below the silica matrix coating layer. For example, in connection with the process according to the present invention, in an alternative embodiment, a transparent conductive oxide coating may be applied to the glass substrate, preferably prior to the deposition of the silica and copper coating compositions.</p><p>According to a second aspect of the invention, preferably made according to the first aspect of the invention, (i) a glass substrate; and (ii) a silica matrix coating layer, the silica matrix coating layer comprising: (a) at least 50% by weight silica; and (b) copper-containing particles deposited on and/or embedded within the silica matrix coating layer in an amount from 1 to 50% by weight. with a silica matrix coating layer, the bacterial growth on the substrate is reduced by at least 10% compared to the uncoated glass substrate, and the inactivation of viruses on the substrate is reduced by at least 10% compared to the uncoated glass substrate. Provided is an antibacterial coated glass substrate which is increased by at least 10% compared to the present invention.</p><p>Also in relation to the second aspect of the invention, the antibacterial and/or antiviral coated glass substrate is preferably toughenable. That is, a coated glass substrate provided with an antibacterial and/or antiviral coating can be heated to a temperature of at least 600°C and still retain antibacterial and/or antiviral properties. More preferably, the coated glass substrate provided with the antibacterial and/or antiviral coating can be heated to a temperature of at least 650°C and still retain the antibacterial and/or antiviral properties. Heat treated or annealed coated glass is desirable for a variety of architectural and automotive glazing applications. The fact that the coated glass substrates according to the first and second aspects of the invention retain both their antibacterial and antiviral properties after heat treatment is beneficial and surprising.</p><p>Also in connection with the second aspect of the invention there is preferably provided an antimicrobial coated substrate, wherein the antimicrobial coated substrate is free of at least gram-positive and/or gram-negative bacteria within 24 hours. resulting in a 2 log reduction or resulting in a 2 log reduction in virus.</p><p>More preferably, the antimicrobial coated substrate provides at least a 2 log reduction in Gram-positive and/or Gram-negative bacteria within 2 hours. Even more preferably, the antimicrobial coated substrate provides at least a 3 log reduction in Gram-positive and/or Gram-negative bacteria within 2 hours. A 2 log reduction or 2 log kill will reduce the microbial colony to 10,000 bacteria after a 99.0% reduction, and a 3 log kill will reduce the microbial colony to 1,000 bacteria after a 99.9% reduction.</p><p>Furthermore, in connection with the second aspect of the invention, there is preferably provided an antiviral coated glass substrate, wherein the antiviral coated glass substrate provides at least a 2 log reduction in viruses within 24 hours. . More preferably, the antiviral coated glass substrate provides at least a 2 log reduction in Gram-positive and/or Gram-negative bacteria within 2 hours.</p><p>The antimicrobial coated glass substrate according to the second aspect of the invention may further include at least 1.0% by weight of zirconium. Zirconium is preferably present as an oxide. According to a third aspect of the invention, preferably an architectural application or An automotive glazing is provided.</p><p>According to a fourth aspect of the invention, preferably the use of antibacterial and/or antiviral coated glass substrates made by the process according to the first aspect of the invention, and/or insulating glazing units, for automotive applications. A second aspect of the invention for use in the making or during transport or transport applications of glazing units, electronic devices, furniture, splashbacks or screens, medical containers, wall coverings, touch screens, mirrors or glass bottles, refrigeration articles. An antibacterial and/or antiviral coated substrate is provided.</p><p>It is therefore to be understood that all aspects of the invention relating to the first aspect of the invention also apply in relation to the second, third and fourth aspects of the invention, as appropriate.</p><p>Embodiments of the invention will now be described, by way of example only, with reference to the following examples and drawings.</p>

<figref num="1">Figures 1a, 1b, 1c, and 1d compare the use of (a) nitric acid, (b) hydrochloric acid, (c) citric acid at room temperature, and (d) citric acid at 60°C. Figure 3 illustrates a time-dependent FTIR spectrum of a sol-gel reaction carried out in acetone alcohol.</figref><figref num="2">When using different acid catalysts, (a) the Si-OC spectral peak at 788 nm, (b) the Et-OH peak at 881 nm, and (c) the Si-O-Si peak at 1140 nm change over time. This diagram shows how the changes occur.</figref><figref num="3">Among different solvents, (a) in propylene glycol, (b) in diacetone alcohol, (c) in 3-methoxy-1-butanol, and (d) in propylene glycol methyl ether, using citric acid as a reaction catalyst. Figure 1 illustrates the time-dependent FTIR spectra of a sol-gel reaction refluxed at 60 °C.</figref><figref num="4">Illustrated is a comparison of FTIR spectra of various solvents using citric acid at 60 °C. Figures 4a, 4b illustrate the starting point of the spectrum. Figure 4c illustrates how the spectral peak at 788 nm changes with time. Figure 4d illustrates how the spectral peak at 881 nm changes with time.</figref><figref num="5">(a) Precursor solution H or (b) Precursor solution I are used to illustrate the progress of the reaction using propylene glycol as a solvent.</figref><figref num="6">Figure 3 illustrates the growth of the Et-OH peak at 881 nm and thus the progress of the hydrolysis reaction for different concentrations of citric acid where propylene glycol is used as a solvent.</figref><figref num="7">(a) Illustrates the dissolution of copper in the coating solution during a roller coating test. (b) Illustrates the dissolution of copper using different acids. (c) Illustrating the dissolution of copper using different copper particle sizes. (d) Illustrates the dissolution of copper using different citric acid concentrations.</figref><figref num="8">Figure 2 illustrates the particle size distribution in solution of suspensions of Nanotec and Promethean copper particles in terms of volumetric density.</figref><figref num="9a">(a) Illustrated SEM cross-sectional images of copper particles showing the growth of the oxide shell of the coated glass sample before and after the simulated thermal strengthening treatment of sample 9d.</figref><figref num="9b">(b) Illustrated SEM cross-sectional images of copper particles showing the growth of the oxide shell of the coated glass sample before and after the simulated thermal strengthening treatment of sample 9c.</figref><figref num="9c">(c) Illustrated SEM cross-sectional images of copper particles showing the growth of the oxide shell of the coated glass sample before and after simulated thermal strengthening treatment of sample 9c.</figref><figref num="10">Figure 3 is a SEM image processed by ImageJ software of sample 35a highlighting the surface coverage of copper within the sample.</figref><figref num="11">Figure 17c is a graph of copper surface coverage as a percentage (%) anti-virus performance (%R) for samples 33a, 34a, 35a and 33c, 34c and 35c of Table 17c.</figref><figref num="12">Figure 17c is a graph of exposure time (hours) anti-virus performance (%R) for samples 33a and 35a of Table 17c.</figref>

[material]

Metallic copper particles were obtained from Nanotec SA and Promethean Particles Ltd. Cuprous oxide particles were obtained from American Chemet Corporation and Nordox AS. TEOS is tetraethyl orthosilicate (also called tetraethoxysilane and abbreviated as TEOS), which has the formula Si(OC₂H₅)₄has orthosilicic acid, Si(OH)₄is the ethyl ester of This is available from Merck.

[Experiment example]

[Preparation of coating solution]

[1. Preparation of tetraethyl orthosilicate sol-gel precursor solution under mild reaction conditions]

A series of precursor solutions containing silica were prepared in connection with the present invention under mild reaction conditions. For each coating solution, tetraethyl orthosilicate (TEOS) was hydrolyzed to produce a silica solution. Hydrolysis of tetraethyl orthosilicate (TEOS) was accomplished using either (i) water in the presence of a weak acid, or (ii) water in the presence of an organic solvent, such as a diol. Tetraethyl orthosilicate (TEOS) was mixed with water and either a weak acid or a diol while stirring at a low temperature, ie, a temperature between 20°C and 80°C. The weak acid was a carboxylic acid, specifically citric acid.

When acid was used with water to hydrolyze TEOS, the reaction was carried out in an organic solvent. Appropriate organic solvents were selected from diacetone alcohol (DAA), propylene glycol methyl ether (PGME) or 3-methoxy-1-butanol. When the hydrolysis reaction took place in the absence of acid, ie when a diol was utilized to hydrolyze TEOS, the preferred organic solvent was preferably a diol, such as propylene glycol.

Details of the component amounts of each precursor solution illustrated and illustrated in FIGS. 1a to 1d, 2a to 2c, 3a to 3d, 4a to 4d, 5a, 5b, and 6 are shown in Table 1.

<tables><img file="JP2023542156A_D0001.tif" /></tables>

The progress of the TEOS hydrolysis reaction was followed using FTIR analysis. FTIR spectra of a series of TEOS hydrolysis reactions using different organic solvents and different acids are illustrated in Figures 1a-1d, 3a-3d, 4a, 4b, 5a, and 5b. The hydrolysis reaction was identified as complete when the spectral peaks at 881 nm (Et-OH) and 788 nm (Si-OC) became stable. Figures 1a-1d and 2a-2c show the progress of the hydrolysis reaction in citric acid (precursor solution C), hydrochloric acid (precursor solution A) and nitric acid (precursor solution C) using diacetone alcohol as the solvent of choice. Compare with B).

The inventors have observed that the reaction rate of the hydrolysis reaction can be varied according to the selected temperature. For example, it has been observed that the rate of hydrolysis reactions can be increased using elevated temperatures, specifically temperatures in the range of 60°C to 80°C. Specifically, Figures 1c and 1d show the results at room temperature (precursor solution C) and 60 °C (precursor solution D), respectively, using diacetone alcohol as the solvent and citric acid as the selected organic acid. Figure 2 illustrates differences in reaction rates of TEOS hydrolysis. When high temperature was used for the TEOS hydrolysis reaction, the solution was heated under reflux to prevent evaporation of solvent and water.

Figures 3a-3d and 4a-4d illustrate the difference in kinetics of hydrolysis of TEOS using various solvents with citric acid as the selected organic acid. Precursor solutions D to G in Table 1 were used. It was determined that the reaction rate of propylene glycol was the highest and the hydrolysis reaction was completed after 1 hour.

Figure 5a shows the progression of the FTIR spectrum of the hydrolysis reaction of TEOS in propylene glycol, with decreasing amount of citric acid as described for precursor solution H in Table 1. The hydrolysis reaction was judged to be complete after 3 hours.

Figure 5b shows the progression of the FTIR spectrum of the hydrolysis reaction of TEOS in the absence of organic acids and the decrease in the amount of water as described for precursor solution I in Table 1. The hydrolysis reaction was judged to be complete after 3 hours.

Figure 6 shows the evolution of the Et-OH peak at 881 nm over time for precursor solutions G to I.

[2. Preparation of copper coating solution]

Following the preparation of the precursor silica solutions described in Section 1, each solution was further diluted with solvent and copper-containing particles were added. In connection with the present invention, the inventors have shown that use of the mild reaction conditions described in Section 1 above produces coating solutions with improved stability with respect to dissolution of copper in the coating solution. I found it. In contrast, we found that when using more severe conditions, for example when using a strong inorganic acid such as hydrochloric acid as a sol-gel reaction catalyst, the dissolution of copper starts with the addition of the inorganic acid and proceeds rapidly. I discovered that.

Figure 7a illustrates the dissolution of copper in a silica coating solution in a roller coating test over a 2 hour period where the silica coating solution included hydrochloric acid. The inventors observed a color change in the coating solution over 2 hours as a result of the dissolution of copper in the solution. While not wishing to be bound by any particular theory, the inventors understand that color changes may occur as a result of complexes formed with copper.

The percentage of copper dissolved in the silica coating solution was determined by removing undissolved copper particles and analyzing the amount of copper in the remaining solution using inductively coupled plasma optical emission spectroscopy (ICP-OES). The amount of copper remaining in solution is illustrated in Figure 7a.

The effect of using inorganic and organic acids on the dissolution rate of copper for silica coating solutions containing 0.1 weight percent copper was investigated with limited exposure to oxygen, i.e. in a closed system, with stirring for 15 hours. The results are illustrated in Figure 7b.

The inventors found that it is possible to achieve further reduction in the dissolution rate of copper by lowering the concentration of organic acids used in the sol-gel hydrolysis reaction of TEOS, as shown in Figure 7d. .

Additionally, we found that when decreasing the concentration of organic acid, it was preferable to increase the reaction time in order to allow the sol-gel hydrolysis reaction of TEOS in Section 1 above to proceed sufficiently. I paid attention to that.

Additionally, the inventors have discovered that by reducing the exposure of copper-containing coating solutions to oxygen, the rate of copper dissolution can be slowed. This was accomplished either by encapsulating the solution, blanketing the solution with nitrogen, or injecting the solution with an inert gas.

The inventors further discovered that the size of the copper particles has also been shown to play a role in stabilizing the dissolution of copper in the coating solution. Copper with a smaller average particle size was shown to dissolve faster than copper with a larger particle size when exposed to oxygen and stirred for 2 hours with constant agitation in the same solvent. The results of these investigations are shown in Figure 7c. The size of copper particles in solution was determined using laser diffraction analysis on a Malvern Mastersizer. The copper particle size distributions of the two copper dispersions A and B used in connection with the present invention are shown in Figure 8. The particles provided by copper dispersion A have a size range from 500 nm to 8.5 microns, while the particles provided by copper dispersion B have a size range from 200 nm to 3 microns. Larger copper particles required increased agitation to remain suspended in the coating solution, while smaller copper particles remained suspended even with reduced agitation. As the need for agitation is reduced, the rate of copper dissolution is also reduced.

<tables><img file="JP2023542156A_D0002.tif" /></tables>

[3. Deposition of copper coating solution by roller coating followed by heat treatment to obtain coated glass samples of silica matrix layer containing copper particles]

The coated glass samples demonstrated the potential antibacterial and antiviral effects of the silica matrix layer embedded with copper particles formed from the coating solution obtained from the sol-gel reaction of tetraethyl orthosilicate (TEOS) with copper particles as described above. and adjusted to evaluate durability and applied by roller coating onto a float glass substrate as follows.

Coating solutions 1 to 7 were prepared using precursor solution C in Table 1 and stirred at room temperature for 4 hours. After stirring, these coating solutions were diluted with propylene glycol, diacetone alcohol, and copper dispersion A or B to achieve the weight percentages of silica and copper shown in Table 3.

Coating solutions 8-12 were prepared using precursor solution D from Table 1 and stirred at 60 °C for 4 h. After stirring, these coating solutions were diluted with propylene glycol, diacetone alcohol, and copper dispersion A or B to achieve the weight percentages of silica and copper shown in Table 3.

Coating solution 13 was stirred at 80°C for 3 hours using precursor solution I from Table 1. After stirring, the coating solution was diluted with propylene glycol, diacetone alcohol, and copper dispersion A or B to achieve the weight percentages of silica and copper shown in Table 3.

Copper dispersions A and B are listed in Table 2 above. Coating solutions 1-13 all contained 41.55% propylene glycol by weight.

<tables><img file="JP2023542156A_D0003.tif" /></tables>

In each experiment, the roller coater equipment used to generate the test samples was a Burkle easy-Coater RCL-M 700. It comprises a smooth EPDM rubber applicator roller material and a patterned and engraved steel doctor roller. Each of coating solutions 1-13 was sequentially applied to the roller coater by pumping into a channel on the roller coater between the doctor roller and the applicator roller and recirculated. In each case, the coating solution was applied to a glass substrate with dimensions of 30 cm x 40 cm by means of an application roller. The glass substrate used comprised a soda lime silicate glass such as float glass available from NSG. Typical soda-lime silicate glass compositions, in weight percent, e.g., SiO₂ 69~74%, Al₂O₃, Na₂O 10~16%, K₂O 0~5%, MgO 0~6%, CaO 5~14%, SO₃ 0~2%, and Fe₂O₃ Contains 0.005~2%.

<tables><img file="JP2023542156A_D0004.tif" /></tables>

Pinch is the compression between the applicator roller and doctor roller, offset is the compression between the applicator roller and the glass substrate, and roller speed is the speed of the applicator roller, doctor roller, and transport conveyor.

After applying the coating, the glass substrate was immediately heated in a convection oven at a temperature of 200°C to 300°C to cure the coating. In order to further densify the formed silica matrix coating layer and simulate the glass strengthening process, a heat treatment of the glass surface to 650 °C was applied to some samples. Table 5 lists the curing conditions employed for each sample.

<tables><img file="JP2023542156A_D0005.tif" /></tables>

[4. Deposition of copper coating solution by spray coating followed by heat treatment to obtain coated glass samples of silica matrix layer containing copper particles]

[4.1. Samples made using a single fixed spray head]

Coated glass samples were prepared with embedded copper particles formed from a coating solution obtained from the sol-gel reaction of tetraethyl orthosilicate (TEOS) and copper particles described above and applied to a float glass substrate by spray coating. The antiviral effect of the silica matrix layer was evaluated.

Coating solutions 14-28 were prepared using precursor solution E in Table 1 and stirred at 60 °C for 6 hours. After stirring, these coating solutions were diluted with propylene glycol methyl ether, isopropanol, and copper dispersions B to E as shown in Table 6. Copper dispersions B to E are listed in Table 2. All coating solutions 14-18 contained 75% by weight isopropanol.

The spray coating equipment used incorporated a fixed hydraulic atomization spray nozzle with a 72 degree spray angle, and the glass moved below the spray nozzle on a conveyor at room temperature.

<tables><img file="JP2023542156A_D0006.tif" /></tables>

Each coating solution shown in Table 6 was individually applied to glass substrates with dimensions of up to 30 cm x 40 cm at room temperature.

<tables><img file="JP2023542156A_D0007.tif" /></tables>

The glass substrate used included a soda lime silicate glass such as float glass available from NSG. A typical soda-lime silicate glass composition has, in weight percent, e.g.₂ 69~74%, Al₂O₃, Na₂O 10~16%, K₂O 0~5%, MgO 0~6%, CaO 5~14%, SO₃ 0~2%, and Fe₂O₃ Contains 0.005~2%.

After applying the coating, the substrate is dried on a heating conveyor at 40-50 °C for 1-2 minutes and then transferred to a convection oven for a further heat treatment of up to 140-180 °C for 5 minutes and coated. hardened. To further densify the silica matrix coating layer and simulate the glass strengthening process, further heat treatment to 650 °C was applied to some of the samples as listed in Table 8.

<tables><img file="JP2023542156A_D0008.tif" /></tables>

[4.2. Samples created using multiple fixed and traversing spray heads]

To simulate large-scale production, samples using multiple stationary or traversing spray heads were also produced as larger substrate sizes need to be coated. Each coating was applied individually to a glass substrate with a width of up to 70 cm, dried and cured as described in 4.1 above.

Coating solutions 29-38 were prepared using precursor solution E from Table 1 and stirred at 60 °C for 6 h. After stirring, these coating solutions were diluted with propylene glycol methyl ether, isopropanol, and copper dispersions B, C, and D as shown in Table 8a. Coating solutions 29-32 contained 75% by weight isopropanol. Coating solutions 33-35 contained 25% by weight isopropanol.

Coating solutions 36-38 were prepared using precursor solution E from Table 1 and stirred at 60 °C for 6 h. After stirring, these coating solutions were diluted with propylene glycol methyl ether, propylene glycol, isopropanol, and copper dispersion B. Coating solutions 36-38 contained 1% by weight isopropanol and 5% by weight propylene glycol.

<tables><img file="JP2023542156A_D0009.tif" /></tables>

For coating solutions 29-32, a spray coating device was used that incorporated multiple fixed hydraulic atomization spray nozzles, each with a 72 degree spray angle, in which the glass moved below the spray nozzles on a conveyor at room temperature. For coating solutions 33-35, a spray coating device incorporating a single hydraulic atomization spray nozzle with a 110 degree spray angle attached to a traverse spray system was used. For coating solutions 36-38, a spray coating device incorporating a single air atomizing LVMP spray nozzle attached to a traverse spray system was used. Each coating solution shown in Table 6 was applied individually to glass substrates with dimensions up to 30 cm x 40 cm at room temperature.

<tables><img file="JP2023542156A_D0010.tif" /></tables>

<tables><img file="JP2023542156A_D0011.tif" /></tables>

<tables><img file="JP2023542156A_D0012.tif" /></tables>

The glass substrate used included a soda lime silicate glass such as float glass available from NSG. A typical soda-lime silicate glass composition has, in weight percent, e.g.₂ 69~74%, Al₂O₃, Na₂O 10~16%, K₂O 0~5%, MgO 0~6%, CaO 5~14%, SO₃ 0~2%, and Fe₂O₃ Contains 0.005~2%.

For coating solutions 31-32, after applying the coating, the substrates were dried on a heating conveyor at 40-50 °C for 1-2 min, followed by a further heat treatment of up to 140-180 °C for 5 min. Transferred to a convection oven to cure the coating. To further densify the silica matrix coating layer and simulate the glass strengthening process, a further heat treatment to 650 °C was applied to some of the samples as listed in Table 8e. For coating solutions 33-35, after applying the coating, the substrates were dried at room temperature and then transferred to a convection oven and heat treated for an additional 5 minutes at 150 °C or 200 °C as described in Table 8e. . For coating solutions 36-38, after applying the coating, the substrate was dried in a convection oven set at 90°C. A subsequent heat treatment was applied to each sample to increase the surface temperature of the glass to 200 °C to further harden the coating.

Additional samples were made on a full-scale production line. The coating was deposited onto a glass substrate 2.25 m wide and 3.21 m long. For these samples, the spray coating equipment used incorporated up to three air atomizing LVMP nozzles attached to a traverse spray system. Line speeds of up to 6 m/min were used in a two-step curing process. After deposition, the coated substrate was moved down the line and dried in an IR oven set at a temperature of 50100 °C. The dried coated substrate subsequently entered a second IR oven to further cure the coating and increase the glass surface temperature to 150200 °C.

<tables><img file="JP2023542156A_D0013.tif" /></tables>

[Antibacterial and antiviral test]

[5. Antibacterial results for roller-coated glass samples described in Section 3 above]

Coated glass samples deposited by roller coating were prepared using standard protocols based on ISO22196 at University College London (UK), Saniter (Turkey), MGS Laboratories Ltd (UK), and Industrial Microbiological Services Limited (UK). The antibacterial performance was evaluated by Samples were tested for E. coli (E.Coli ATCC 8739) and Staphylococcus aureus (S.Aureus ATCC 6538P) over a 24 hour period.

According to ISO22196, antimicrobial activity (ie log reduction) R was calculated according to Equation 1. Additionally, the percentage of killed bacteria was calculated for both untreated specimens immediately after seeding (%I) and untreated specimens after incubation time t (%R) according to Equation 2 and Equation 3, respectively.

<math num="1"><img file="JP2023542156A_D0014.tif" /></math>

<math num="2"><img file="JP2023542156A_D0015.tif" /></math>

<math num="3"><img file="JP2023542156A_D0016.tif" /></math>

U₀is the average number of viable bacteria (cells/cm²) and U_tis the average number of viable bacteria (cells/cm²) and A_tis the average number of viable bacteria (cells/cm²).

[Experiment result 1]

<tables><img file="JP2023542156A_D0017.tif" /></tables>

<tables><img file="JP2023542156A_D0018.tif" /></tables>

<tables><img file="JP2023542156A_D0019.tif" /></tables>

<tables><img file="JP2023542156A_D0020.tif" /></tables>

The results in Tables 9-12 show that as the copper concentration in the coating solution increases, the antibacterial performance against E.Coli 8739 increases. The results in Table 10, particularly for E.Coli 8739, suggest improved performance with smaller sized copper particles. Sample 2a (using copper dispersion A) resulted in a percentage of killed bacteria of 94.75% versus the uncoated reference, compared to 98.68% for sample 3a (using copper dispersion B).

Tables 9 and 10 show the antibacterial performance against S.Aureus 6538 and the uncoated reference even when using the lowest copper concentrations and larger particles supplied by copper dispersion A (sample 1a). More than 99% of the bacteria (more than 2 log reduction) were killed compared to

[Experiment result 2]

<tables><img file="JP2023542156A_D0021.tif" /></tables>

The results in Table 13 show that both sample 6a and sample 7a (using particle dispersions A and B with 0.4 wt% copper during coating) showed &gt;99.9% of the bacteria versus the uncoated reference. This indicates that the cells have died (more than 3 logarithmic decrease).

[Experiment result 3]

<tables><img file="JP2023542156A_D0022.tif" /></tables>

<tables><img file="JP2023542156A_D0023.tif" /></tables>

The results in Table 15 show that by increasing the copper concentration (from sample 11c to 9c) while keeping the curing method constant, the antibacterial activity increased to an average of 1.87 (98.67% of the bacteria compared to the uncoated reference). ) and are shown to have multiple repeats that kill &gt;99% of the bacteria versus the uncoated reference.

The results in Tables 14 and 15, specifically samples 9a, 9b, and 9c, also show that the temperature and duration of initial curing (200-300°C) have a significant impact on antimicrobial activity.

<tables><img file="JP2023542156A_D0024.tif" /></tables>

The results in Table 15a show that the samples that did not undergo the 650°C heat treatment (samples 31a and 32a) showed more than a 4 log (99.99%) reduction in E.Coli 8739 after 2 hours, and S.Coli 8739 after 2 hours. Aureus is shown to achieve a reduction of more than 3 logs (99.9%). For samples that received an additional 650 °C heat treatment (samples 31b and 32b), the time required to achieve more than a 2 log (99%) reduction in antimicrobial performance increased to 6 hours.

[6. Antiviral results for roller-coated and spray-coated glass samples described in Sections 3 and 4]

[Experiment result 4]

Coated samples deposited by roller and spray coating were evaluated for antiviral performance by the University of Cambridge using a protocol based on ISO21702. The virus strain used was mouse hepatitis virus A59 (MHV-A59), a well-established coronavirus that can act as a surrogate for SARS-CoV-2. This virus strain belongs to the same betacoronavirus family as SARS-CoV-2, is nearly structurally identical, and has been widely used in stability studies.

The coating samples deposited by spray coating in Section 4.2 were evaluated for antiviral performance by Virology Research Services Limited using a protocol based on ISO21702. The virus strain used was human coronavirus NL63.

Infectivity was assessed by scoring samples for virus-induced cell death and expressed as residual infectious titer (TCID50). These values were then used to calculate the log reduction according to Equation 4. Furthermore, the percentage of inactivation was calculated for untreated specimens immediately after seeding (%I) and untreated specimens after culture time t (%R) according to Equation 5 and Equation 6, respectively.

<math num="4"><img file="JP2023542156A_D0025.tif" /></math>

<math num="5"><img file="JP2023542156A_D0026.tif" /></math>

<math num="6"><img file="JP2023542156A_D0027.tif" /></math>

V₀is the average TCID50/ml recovered from untreated specimens immediately after seeding, and V_tis the average TCID50/ml recovered from untreated specimens after incubation time t, and C_tis the average TCID50/ml recovered from treated specimens after incubation time t.

TCID50 is the median tissue culture infectious dose, and is the concentration at which 50% of the cells are infected when a diluted virus solution is inoculated on a well plate in which cells have been cultured.

<tables><img file="JP2023542156A_D0028.tif" /></tables>

The results in Table 16 show that sample 15c (a sample spray coated using a coating solution consisting of 0.04 wt% copper and 0.5 wt% silica) showed that mouse hepatitis virus This shows that 47.88% of the virus was inactivated, and 94.52% of the initial virus amount was inactivated.

[Experiment result 5]

<tables><img file="JP2023542156A_D0029.tif" /></tables>

The results in Table 17 show that roller-coated sample 12d lost 99.91% of the SARS-Cov-2 virus after 3 hours and 97.73% after 24 hours against both the uncoated reference and the initial viral load. Indicates activation.

Additional antiviral tests were performed against murine hepatitis virus A49, SARS-Cov-2 (UK strain), human coronavirus 229E, human coronavirus NL63, and influenza A.

[Experiment result 6]

<tables><img file="JP2023542156A_D0030.tif" /></tables>

The results in Table 17a show that for the same mass of copper, using copper dispersion B in sample 30a (compared to using copper dispersion C in sample 20a) resulted in a 0.6 log decrease in antiviral performance (74.85 %) to 1.05 (91.02%). Without wishing to be bound by any particular theory, we believe that this results in smaller particle sizes (as shown in Figure 8) leading to greater surface area coverage of the copper particles. I think it could be because of this.

This result also shows that increasing the mass ratio of copper to silica in the coating solution from 0.08 (sample 9d) to 0.4 (sample 29a) reduces the antiviral performance from 0.28 log reduction (47.91% kill) to 0.6 (74.85% kill). It is also shown that there is an improvement in the mortality (killing).

<tables><img file="JP2023542156A_D0031.tif" /></tables>

The results in Table 17b show that sample 32a has significantly higher antiviral performance even though the concentration of copper in the coating solution is half that of sample 31a. Without wishing to be bound by any particular theory, we believe that this results in smaller particle sizes (as shown in Table 22) leading to greater surface area coverage of the copper particles (as shown in Table 22). As shown in Figure 8), we believe that this may be due to the following.

<tables><img file="JP2023542156A_D0032.tif" /></tables>

The results in Table 17c were obtained by linearly increasing the concentration of copper in the coating solution for the samples cured at 200°C (Samples 33c to 35c) for a 6 hour exposure time as illustrated in Figure 11. The antiviral performance increases from a logarithmic decrease of 1.20 (93.65% killing) to 1.79 (98.40% killing) and then to 3.20 (99.94% killing).

By linearly increasing the concentration of copper in the coating solution of the samples cured at 150 °C (sample 33a to sample 35a), the antiviral performance after 6 hours of exposure time was determined as illustrated in Figure 11. , a logarithmic decrease of 1.07 (91.45% mortality) to 1.38 (95.84% mortality), which increases to 2.79 (99.84% mortality).

By linearly increasing the exposure time from 2 to 6 hours, the samples cured at 150 °C (sample 33a sample 35a) showed a log reduction from 0.66 to 0.75 to 1.07, as illustrated in Figure 12. increases, and the logarithmic decrease increases from 1.19 to 1.69 to 2.79.

The results for sample 35a plus the lamination cycle and sample 35a plus treatment K show that good antiviral performance was achieved by subjecting the sample to laminating thermal cycles and harsh cleaning via the "friction rig test". It was maintained even after being exposed to the drug (listed in Table 20).

<tables><img file="JP2023542156A_D0033.tif" /></tables>

The results in Table 17d show that increasing the concentration of silica in the coating solution from 1.5% to 2.5% by weight (samples 36c, 37c, 38c), while keeping the copper concentration constant, negatively affected the antiviral performance. Indicates that there was no impact. That is, increasing the silica thickness around and above the copper particles had no adverse effect on performance.

[7. Durability testing of roller coated samples described in Section 3]

[EN1096 test]

Coated glass samples deposited by roller coating as listed in Table 5 were prepared using SO₂They were evaluated for relative durability (or degradation) by exposure to , condensation, salt and abrasion cycles. The results of the durability test are summarized in Table 19.

The classification system is based on the position of the coated surface when the coated glass is installed. This installation location determines the type and extent of erosion (eg, humidity, air pollution, abrasion, etc.) that the coating will experience during its lifetime.

For EN1096 class B, that is, coated glass can be used as monolithic glazing, but the coated surface should be on the internal surface of the building. For EN1096 class S, i.e. the coated surfaces of the glass may be placed on the exterior or interior surfaces of buildings, but these types of coated glass may only be used in specifically defined applications, e.g. may only be used.

<tables><img file="JP2023542156A_D0034.tif" /></tables>

<tables><img file="JP2023542156A_D0035.tif" /></tables>

[Cleaning agent compatibility]

Coated glass samples deposited by roller coating as listed in Table 5 are subjected to 3650 strokes of detergent action from a modified oil friction rig test with a 1Kg load on the coated surface. 3650 cleaning cycles were simulated and the relative durability (or deterioration) was evaluated. To apply the cleaning agent, an 8 x 9 cm piece (88% polyester/12% polyamide) of multipurpose microfiber cloth was used, mounted on a modified jig and moistened with cleaning agent as needed during the run. . For the synthetic sweat solution, a rubber strip was used instead of a microfiber cloth, 1000 strokes were performed, and a load of 0.15 kg was used. The results of the test are listed in Table 21.

<tables><img file="JP2023542156A_D0036.tif" /></tables>

<tables><img file="JP2023542156A_D0037.tif" /></tables>

[8. Surface analysis of roller coated and spray coated samples]

ICP-OES analysis was performed on the coated samples to assess the total amount of copper in the coating by the method steps described below.

- A 5 x 5 cm test sample was placed in a 90 mm Petri dish with the coated side facing up.

.2ml of concentrated H₂S.O.₄was pipetted onto the coated surface.

-The sample was then placed on a hot plate set at 100°C for 10 minutes.

-The temperature was then increased to 150°C for 10 minutes, followed by 200°C until the sample started fuming (typically about 5 minutes).

- Next, the sample was allowed to cool and was washed into a 50 ml volumetric flask.

.Next, H₂S.O.₄ Samples were analyzed by ICP-OES using Cu standards and matched matrices.

This method was used to evaluate the extent of damage to the coating after various durability tests, as shown in Table 23.

Scanning electron microscopy studies were used to analyze the appearance and distribution of copper particles associated with the silica matrix coating layer. Coated samples were taken and mounted on aluminum stubs before being coated with a thin layer of platinum (providing a uniform conductive surface) prior to examination using scanning electron microscopy (SEM).

Figures 9a-9c illustrate the size, shape and structure of copper particles embedded in the silica coating layer of sample 9c and sample 9d before and after the simulated strengthening process.

Backscattered electron (BSE) images highlight differences in chemical composition, with materials with higher atomic numbers (i.e., copper nanoparticles) appearing brighter, so these images were created using ImageJ software (https://imagej.nih). gov/ij/index.html). An example of a processed image of sample 35a can be seen in FIG. 10. The approximate size and number of bright features on the surface of each sample was then determined and this data was used to calculate the percentage of the two-dimensional surface covered with copper, as shown in Table 22.

<tables><img file="JP2023542156A_D0038.tif" /></tables>

Figure 11 shows the relationship between surface coverage of copper particles and antiviral performance relative to the uncoated reference (%R).

<tables><img file="JP2023542156A_D0039.tif" /></tables>

Table 23 shows that for Sample 35a after Test K, the minimum amount of copper retained was 76%. Table 17c in Section 5 showed that this sample 35a maintained an antiviral performance of 96.08% (1.41 log reduction).

[9. Appearance evaluation]

<tables><img file="JP2023542156A_D0040.tif" /></tables>

<tables><img file="JP2023542156A_D0041.tif" /></tables>

Thus, in summary, there is a large and growing market for durable, antimicrobial, and/or antiviral coatings on glass with high light transmission and excellent aesthetic appearance. Copper has been shown to have some antimicrobial activity, but copper-containing coatings that exhibit high antimicrobial efficacy generally have durability or optical problems, or cannot be produced at sufficient scale. , or not capable of being strengthened to the extent required. While sol-gel formulations are used to create durable coatings on glass and provide the necessary transparency, the method of deposition involves harsh reaction conditions and materials that are often incompatible with metal particles. Ru. In connection with the present invention, we have provided a coating that can be applied to a variety of substrates while retaining durability and optical clarity alongside excellent antibacterial and antiviral properties even on an industrial scale. Disclosed herein is a process that utilizes sol-gel technology under very mild conditions.

Thus, the above findings described by the inventors indicate that it is possible to formulate coating solutions suitable for industrial fabrication of antibacterial and/or antiviral coated glass substrates. This is made possible by employing mild sol-gel reaction conditions using weak acids and/or diols to proceed the hydrolysis reaction of tetraethyl orthosilicate to silica, thereby allowing the final coating to which the copper dispersion is added. Slowed down the dissolution rate of copper in solution.

We demonstrate that silica and copper coating solutions can be applied to glass substrates on an industrial scale by roller coating or spray coating, resulting in coated glass substrates that exhibit both antibacterial and antiviral effects. did. Namely, the above results have been shown to kill over 99.9% of bacteria against E.Coli 8739 and S.Aureus 6538 after 24 hours compared to the uncoated reference; provides evidence of &gt;99.9% inactivation of SARS-Cov-2 (UK strain) virus after 3 hours compared to uncoated reference.

Furthermore, it was found that increasing the mass of copper improves both antiviral and antibacterial performance. Furthermore, the antiviral performance was found to increase with increasing surface coverage of copper. By reducing particle size, greater surface coverage can be achieved with the same mass of copper. For example, Figure 11 shows that at a virus exposure time of 6 hours, 1.6% coverage of copper particles achieved over 90% killing (1 log reduction) against human coronavirus NL63; A coverage rate of 3.1% indicates that more than 99% killing (2 log reduction) was achieved against human coronavirus NL63.

A similar situation has been experienced with antibacterial performance. For example, for non-reinforced glass samples, 99.9% was achieved after 2 hours against both Gram-positive and Gram-negative bacteria (E.Coli ATCC 8739 and S.Aureus ATCC 6538P). An antibacterial effect exceeding (3 log reduction) was achieved.

Although the fortified samples showed decreased performance compared to the non-fortified samples, more than 99% (2 log reduction) antibacterial reduction was achieved even after 6 hours.

The coated substrates also meet the stringent testing requirements of the glass industry and can be used in a variety of glass substrate applications.