Method for eradicating pathogens

Abstract

The present invention relates to a method for eradicating pathogens, in particular to a method for eradicating bacteria in a closed space. The method comprises the use of germicidal UV light of a wavelength of 220 nm, wherein the UV light is emitted by a UV lamp having a lamp cover made of 220 nm-UV transmissive glass. The invention comprises a 220 nm-UV transmissive glass, the use of such UV transmissive glass and a method for its preparation.

Description

Technical Field

[0001] This invention relates to methods for eradicating pathogens, and more particularly to methods for eradicating bacteria in enclosed spaces. The method includes using bactericidal UV light with a wavelength of 220 nm, wherein the UV light is emitted by a UV lamp having a lamp cover made of 220 nm-UV transmissive glass. The invention includes a 220 nm-UV transmissive glass, its uses, and methods for its preparation. Background Technology

[0002] The most relevant pathogens are bacteria and viruses. Pathogens pose a continuous threat to humans and livestock. Numerous methods have been developed for pathogen eradication, including light-based removal. The current SARS-CoV-2 pandemic has increased the need for effective and specific pathogen eradication methods, particularly viral eradication.

[0003] Pathogens can become a major problem in hospitals, prisons, and nursing homes, where people with open wounds, invasive devices such as catheters, and weakened immune systems are at greater risk of infection. Regular disinfection and antibiotics / antiviral agents are possible solutions to these threats. However, disinfectants can be highly aggressive and produce irritating fumes that can themselves damage or reduce the likelihood of effective use of these agents (especially in confined spaces). Antibiotics / antiviral agents can lead to antibiotic resistance in pathogens, rendering the agents largely ineffective.

[0004] Therefore, there is an urgent need for easy-to-use and effective eradication methods to combat pathogens, especially bacteria and viruses, in enclosed spaces such as hospitals, schools, and nursing homes.

[0005] Methods for eradicating pathogens using light have been reported in this field. The so-called "photosensitizer method" is widely used in hospitals and other areas where the risk of pathogens (or other bacterial contamination) is increased. This method utilizes photosensitizers (primarily dye molecules) that are excited when exposed to light. When excited by light, these molecules produce reactive oxygen species, which then eradicate the pathogens.

[0006] However, not all reported methods using photosensitizers are sufficient to eradicate enough microorganisms to effectively prevent infection. This is because the concentration of the photosensitizer may be insufficient to cause significant damage. Additionally, many photosensitizers are hydrophobic. This makes it difficult to disperse the photosensitizer in aqueous environments where microorganisms typically exist, such as biofilms.

[0007] Another approach in this field is known as "ultraviolet sterilization irradiation" (UVGI), which uses short-wavelength ultraviolet (UVC) light to kill or inactivate microorganisms by damaging their nucleic acids and disrupting their DNA, thereby preventing them from performing important cellular functions. UVGI is used in a variety of applications, such as food, air, and water purification.

[0008] UVGI devices can generate sufficiently strong UVC light in circulating air or water systems to create an environment unsuitable for microorganisms such as bacteria, viruses, molds, and other pathogens. UVGI can be combined with filtration systems to disinfect air and water. The application of UVGI for disinfection has been standard practice since the mid-20th century. UVGI is primarily used in healthcare and sterile work facilities.

[0009] UVGI is increasingly being used to disinfect drinking water and wastewater because it keeps facilities closed and allows for circulation to ensure a higher level of UV exposure. In recent years, UVGI has also found new applications in air purifiers.

[0010] However, conventional germicidal UV lamps have been reported to be harmful to the eyes, cause pre-UV-related DNA damage in human skin, and be cytotoxic to exposed mammalian skin.

[0011] Therefore, the harmful effects (including the induction of cancer or other mutagenic diseases) prevent the direct use of conventional UVGI methods to eradicate pathogens on mammalian skin (e.g., the skin of patients, healthcare workers, or livestock).

[0012] Recent reports indicate that far-UVC light can effectively kill bacteria regardless of their drug resistance, without the skin or eye damage associated with conventional bactericidal UV exposure.

[0013] However, in other transmissive covers, UV light absorption is very high at wavelengths from about 200 nm to about 250 nm. For example, UV light cannot sufficiently transmit through conventional glass at wavelengths above 320 nm. Conventional glass does not transmit light at wavelengths below 290 nm. Therefore, a disadvantage of these covers is that they do not allow far-UV light to pass through, or require at least a large amount of energy to ensure adequate UV exposure to the surface to be treated (e.g., the skin to be treated). Summary of the Invention

[0014] On one hand, the present invention relates to a method for eradicating pathogens, the method comprising exposing the pathogens to bactericidal UV light at a wavelength of 222 nm, wherein the UV light is irradiated by a UV lamp having a lamp cover made of glass, the transmittance of which is at least 30% at a wavelength of 220 nm and less than 4% at a wavelength of 200 nm. Optionally, in the room in which the method is performed, the ozone concentration may be less than 0.12 mg / m³. 3 .

[0015] The lamp cover, positioned between the light source and the space to be irradiated, has minimal transmittance for 220nm UV light, ensuring sufficient 220nm-UV light intensity reaches the treated space. At 220nm, many pathogens are particularly vulnerable to light irradiation, while human eyes and skin are less sensitive. Furthermore, at 200nm, the lamp cover's light transmittance is very low. This reduction in light intensity at approximately 200nm limits the photolysis rate induced by UV irradiation. Photolysis leads to ozone formation. When ozone levels exceed 0.12 mg / m³... 3 When present at concentrations of ozone, it can become a problem in enclosed spaces (e.g., homes and offices). The method disclosed in this paper reduces ozone formation while ensuring adequate removal of pathogens.

[0016] On the other hand, the present invention relates to a method for eradicating pathogens, the method comprising exposing the pathogens to bactericidal UV light of a wavelength of 220 nm, wherein the UV light is irradiated by a UV lamp having a lamp cover made of glass having a total platinum content of less than 3.5 ppm. Attached Figure Description

[0017] Figure 1 Potential uses of UV-transmissive glass in various LED packages a) through f) are shown. The form of a glass lens [1] allows for focusing or dispersing of UV light, depending on the specific application. In addition, a glass cover [1] can surround a UV source (e.g., a UV-LED) [4], so that UV light is also emitted laterally (see reference). Figure 1 c) to f). The reflective element on the back of the housing [3] can improve the luminous efficiency. Aluminum nitride ceramic (AIN ceramic) with high thermal conductivity can be used as the housing [3]. The LED [4] and the glass cover [1] can be metal welded [2] to the housing [3].

[0018] Figure 2 This shows an alternative to welding glass metal[2] to the housing[3] (see Figure 2 In addition to a), the UV-transmissive glass [1] of the present invention can also be attached to the housing via laser fusing seal [6] (see a) Figure 2(b) to (e)). The LED [4], which can be metal-welded [2] to the housing [3], can be completely encapsulated in a transmissive encapsulating material [5]. This encapsulating material can be a copolymer of methyl methacrylate and methacryloyl oxime. In this example, poly-(methyl methacrylate-co-3-methacryloyl-oxime-2-butanone) is used. Due to the laser-fused-to-metal seal [6], the LED element is completely unaffected by the environment, and therefore, this setup is best suited for harsh environmental conditions, especially when strong acidic cleaners and / or disinfectants are used regularly. Furthermore, aluminum nitride ceramic (AIN ceramic) with high thermal conductivity can be used as the housing [3]. Reflective elements on the back of the housing [3] can further enhance luminous efficacy.

[0019] Figure 3 The transmittance spectra of some glasses according to this disclosure are shown.

[0020] Figure 4 The emission spectrum of the HOK 4 lamp is shown. Detailed Implementation

[0021] UV radiation can break organic bonds. Therefore, it is detrimental to life by damaging biological materials. In addition, many plastics are damaged by UV radiation due to haze, brittleness, and / or decay. At lower wavelengths, UV light causes photolysis, which leads to an increase in ozone concentration in the surrounding air.

[0022] In humans, excessive exposure to UV radiation can lead to acute and chronic harmful effects on the refractive system and retina of the eye. The skin, circadian rhythm system, and immune system may also be affected. The skin and eyes are most sensitive to UV damage in the 265nm to 275nm range.

[0023] Therefore, the wavelengths used in the method according to the present invention include 220 nm. Ultraviolet (UV) light of about 220 nm has antibacterial properties similar to typical bactericidal UV light (254 nm), but does not damage the outer tissue coverings of higher animals (such as the skin of amphibians, reptiles, birds, mammals, or humans).

[0024] Compared to the penetration distance of 254nm light, the limited penetration distance of 220nm light in biological samples (e.g., the stratum corneum) allows for selective antimicrobial treatment without harming mammalian or human skin (such as the skin of patients or healthcare workers).

[0025] Considering the eye, the most important target from a UV risk perspective is the lens. Located at the distal end of the cornea, which is thick enough (500 μm) to allow for low penetration of 220 nm light through the cornea to the lens. Even considering the impact on the cornea from the perspective of photokeratitis, any protective equipment against eye splashes now almost universally used among surgical staff will be expected to adequately protect the cornea from 220 nm UV exposure.

[0026] At the cellular level, bacteria are much smaller than almost any human cell. A typical bacterial cell is less than 1 μm in diameter, while a typical eukaryotic cell ranges in diameter from about 10 to 25 μm. Therefore, 220 nm UV light can penetrate a typical bacterial cell, but it cannot significantly penetrate beyond the periphery of the cytoplasm of a typical eukaryotic cell (such as a human cell) and will attenuate considerably before reaching the eukaryotic cell nucleus.

[0027] In contrast, higher wavelength light from conventional germicidal lamps can reach the human cell nucleus without significant attenuation. Based on these biophysical considerations, while radiation from conventional UVC lamps is cytotoxic and mutagenic to both bacteria and human cells, 220nm UV light is cytotoxic to bacteria but much less cytotoxic or mutagenic to human cells.

[0028] However, UV light with wavelengths of 200 nm and below is useless because sufficient pathogen eradication cannot be achieved at these wavelengths. Furthermore, at wavelengths of 200 nm and below, UV light reacts with oxygen to form ozone, which is an undesirable effect.

[0029] Regardless of the pathogen's drug resistance, UVC light at approximately 222 nm can effectively eradicate pathogens without causing skin and eye damage associated with conventional bactericidal UV exposure.

[0030] The term “eradication” is used in this document for any reduction of pathogens after treatment: according to ISO 22196:2011-08-31, it is more than 90%, more than 95%, more than 99%, more than 99.9%, or more than 99.99%.

[0031] To achieve this eradication, in one embodiment, the present invention relates to a method wherein the UV exposure of the pathogen and / or the surface to be treated ranges from 2000 to 8000 μW·s / cm. 2 2100 to 7000 μW·s / cm 2 2200 to 5000 μW·s / cm 2 Or 2300 to 3000 μW·s / cm 2 In one embodiment, at least about 2500 μW·s / cm 2UV exposure resulted in a 90% reduction in at least one pathogen.

[0032] The method of this invention can be used to eradicate pathogens in enclosed spaces (e.g., homes, hospitals, schools, or nursing homes). The reduction in ozone production and the limited potential for harm to human health make this method ideal for regular or even continuous use. Optionally, the method can be used to eradicate pathogens on UV-sensitive materials (such as UV-sensitive surfaces).

[0033] In one embodiment, the UV-sensitive material can be readily crosslinked with monomers by UV radiation above 250 nm and / or up to 295 nm to produce a specific polymer. In yet another embodiment, the UV-sensitive material can be a gas or liquid sensitive to UV radiation above 250 nm and / or up to 295 nm.

[0034] In yet another embodiment, the UV-sensitive material may be a pharmaceutical composition sensitive to UV radiation above 250 nm and / or up to 295 nm.

[0035] In embodiments, the UV-sensitive material can be the surface of biological tissue, such as the skin of insects, invertebrates, vertebrates, mammals, or humans, for example, molluscs, fish, amphibians, reptiles, birds, mammals, and / or humans, or the shell exoskeleton from arthropods (such as lobsters or insects).

[0036] Therefore, the term "biological tissue surface" as defined according to the present invention includes all biological surfaces that may be damaged by UV radiation above 250 nm and / or up to 295 nm. In one embodiment, the present invention includes biological surfaces that may be damaged by UV radiation outside the 207 to 220 nm wavelength range but not by UV radiation with a wavelength of about 220 nm.

[0037] Within this invention, the term "tissue" is used at any cellular tissue level, between cells and complete organs. A tissue is the totality of similar cells and their extracellular matrix (both working together to perform specific functions) originating from the same organ. Organs are then formed by functionally grouping multiple tissues together.

[0038] Of course, tissues that may be exposed to UV radiation, especially during pathogen eradication methods, should be included. In most cases, these tissues will be epithelial tissue, composed of cells covering the surfaces of organs such as the skin, respiratory tract, reproductive tract, and the lining of the digestive tract. The cells, including the epithelial layer, are linked by semi-permeable tight junctions; thus, this tissue provides a barrier between the external environment and the organs it covers. In addition to this protective function, epithelial tissue also plays a specialized role in secretion, excretion, and absorption. Epithelial tissue helps protect organs from damage caused by microorganisms, injury, and fluid loss.

[0039] Therefore, the methods of the present invention include those methods that may not be applicable or suitable for conventional UVGI methods (e.g., UV treatment of pathogens residing on UV-sensitive surfaces (e.g., skin tissue)) or where eye exposure to UV cannot be avoided.

[0040] The term "mammal" in this text refers to any vertebrate that constitutes the class Mammalia and is characterized by the presence of mammary glands (which produce milk in females to feed their young), the presence of a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish mammals from reptiles and birds, which diverged from them during the Late Triassic period, between 201 and 227 million years ago. There are approximately 5,450 species of mammals. The largest order is rodents, bats, and shrews (shrews, etc.). The next three are primates (apes, monkeys, etc.), cetaceans (cetaceans and even-toed ungulates), and carnivores (cats, dogs, seals, etc.). This definition of mammals also includes humans.

[0041] Therefore, the term "mammal skin" refers to any skin of a mammal, including the skin of livestock, where the term "livestock" is generally defined as domesticated animals raised in an agricultural environment to produce labor and commodities such as meat, eggs, milk, fur, leather, and wool, for example, cattle, goats, horses, pigs, and sheep.

[0042] In addition, the term "mammal skin" also includes human skin, such as that of patients, healthcare workers, people with weakened or deficient immune systems (the elderly, children, post-operative patients, organ transplant recipients, HIV-positive individuals, etc.), and people with an increased likelihood of exposure to pathogens.

[0043] Existing UV lamp covers are made of sapphire, synthetic quartz, or quartz glass (fused silica glass). However, sapphire is very expensive compared to other transmissive materials and cannot be bent, molded, stretched, or melted like glass or metal. Furthermore, it exhibits high UV absorption at UVC wavelengths and almost no transmittance below 250 nm.

[0044] In the embodiments, the transmittance of the glass is at least 30%, at least 35%, at least 40%, or at least 60% at 220 nm and / or at wavelengths [λ] of at least 75% (measured at a thickness of 0.71 mm).

[0045] Quartz and fused silica glass are expensive to manufacture due to their high melting points, as the temperatures and labor required for melting and forming are much higher than for other types of glass. Furthermore, any form other than tubes or sheets must be ground and polished in blocks or ingots. In addition to production costs, these covers also have the disadvantage of requiring a significant amount of energy to ensure adequate UV exposure of the treated object, gas, or liquid.

[0046] However, the glass disclosed herein is suitable for rods, tubes, sheets and bars manufactured by casting, Danner, Vello, heavy drawing and / or downdrawing processes.

[0047] The glass of this invention can possess excellent optical properties. In the embodiments, the refractive index n of the glass is... d (λ = 587.6 nm) is 1.48 to 1.58. The refractive index can be 1.50 or greater.

[0048] The glass described in this article exhibits excellent UV transmittance at wavelengths significantly above 200 nm. The glass possesses one or more of the following optical properties:

[0049] - The UV transmittance at 200 nm is less than 4.0%, and in one embodiment less than 3.0%;

[0050] - The UV transmittance at 220 nm is at least 20%, and in one embodiment at at least 30%, at least 40%, at least 50%, or at least 60%;

[0051] - The UV transmittance at 240 nm is at least 45%, and in one embodiment at least 50%, at least 60%, or at least 70%;

[0052] - UV transmittance at 260 nm is at least 65%, and in one embodiment at least 70% or at least 80%; and / or

[0053] - The UV transmittance at 280 nm is at least 72.5%, and in one embodiment at least 85%.

[0054] In this embodiment, the UV transmittance of the glass at 220 nm (measured at a thickness d = 0.71 mm) is at least 40%.

[0055] Throughout this disclosure, unless otherwise indicated, any reference to transmittance refers to the transmittance at a reference thickness of 0.71 mm. This does not imply that the glass, glass article, or lamp cover has this specific thickness. This thickness is used as a reference for determining transmittance. Transmittance can be measured at different thicknesses, and the results are used to calculate the transmittance value at 0.71 mm.

[0056] The glass and / or glass articles preferably have a transmittance of at least 50%, more preferably at least 70%, at least 80%, or at least 83% at a wavelength of 254 nm. In one embodiment, the transmittance at 254 nm is at most 99.9%, at most 95%, or at most 90%.

[0057] For clarity: indicating transmittance measured at a specific wavelength does not imply that the glass is limited to the indicated thickness. Rather, the thickness indicates the thickness at which transmittance can be measured. Indicating the measured thickness ensures that values ​​can be compared. Those skilled in the art will understand that any suitable glass thickness can be used in the glass covers and devices described below.

[0058] This invention utilizes and relates to glass and glass caps (lamp caps, LED cap glass) that exhibit low UV absorption (i.e., high UVC transmittance) within a certain wavelength range and low transmittance at lower wavelengths, thereby reducing operating energy, lowering operating temperature, and limiting photolysis. Furthermore, the glass and glass caps of this invention are relatively inexpensive and easy to manufacture, can be bent, molded, stretched, or melted to ensure various shapes, and are resistant to most chemicals, as well as temperature and physical stress.

[0059] In one embodiment, the glass has a transmittance of at least 30% at a wavelength of 220 nm and a transmittance of less than 4.0% at a wavelength of 200 nm, wherein the total platinum content of the glass does not exceed 3.5 ppm, and in some embodiments it also has low iron and titanium contents of less than 10 ppm each.

[0060] In one embodiment, Pt contaminants (i.e., Pt) in the glass have been found to be present. 0 Pt 2+ Pt 4+ and Pt 6+ The total platinum content (also referred to as "total platinum content") can reduce UV transmittance between 200 nm and 250 nm. Without being bound by theory, it is assumed that platinum contamination in the glass can induce phase separation by forming nuclei within the glass. The glass of this disclosure may be free of metal contamination or have very low levels of metal contamination, particularly below 3.5 ppm or below 2.5 ppm of Pt contamination. In some embodiments, the Pt contamination of the glass may be above 0.05 ppm or above 0.1 ppm. In other embodiments, it is preferably between 0 and 3.5 ppm, between 0 and 2.5 ppm, between 0 and 2.0 ppm, between 0 and 1.5 ppm, between 0 and 1.0 ppm, between 0 and 0.75 ppm, between 0 and 0.5 ppm, or between 0 and 0.25 ppm. In yet another embodiment, the glass is free of any Pt contamination.

[0061] In yet another embodiment, it has been found that TiO2 contamination in the glass (also referred to as "titanium content") can further reduce UV transmittance between 200 nm and about 250 nm. Therefore, in one embodiment, glass with a TiO2 content of 100 ppm or less, preferably 50 ppm or less, is preferred. Preferably, the amount of TiO2 should be less than 10 ppm, less than 7 ppm, less than 5 ppm, or less than 4 ppm. In other embodiments, the TiO2 content may be between 1 and 10 ppm, between 1.5 and 9.0 ppm, between 2.0 and 8.0 ppm, or between 1 and 5 ppm.

[0062] In yet another embodiment, it has been found that Fe contamination in the glass can further reduce UV transmittance between 200 nm and approximately 250 nm. In this specification, iron content is expressed as parts by weight of Fe₂O₃ in ppm. This value can be determined in a manner familiar to those skilled in the art, i.e., by determining the amount of all iron present in the glass and assuming, for the calculation of the mass fraction, that all iron is present in the form of Fe₂O₃. For example, if 2 mmol of iron is found in the glass, the calculated mass corresponds to 159.70 mg of Fe₂O₃. This procedure takes into account the fact that the amount of individual iron substances in the glass cannot be reliably determined or only through considerable effort. In some embodiments, the glass contains less than 100 ppm of Fe₂O₃, particularly less than 50 ppm or less than 10 ppm. In embodiments, where the iron content is particularly low, the Fe₂O₃ content is less than 10 ppm, less than 8 ppm, or less than 4.5 ppm. Optionally, the Fe2O3 content is between 0.5 and 10 ppm, between 1 and 10 ppm, between 1.5 and 9.0 ppm, between 2 and 8.5 ppm, between 2.5 and 8.0 ppm, or between 3 and 7 ppm.

[0063] It has been found that reducing conditions during melting in the glass of this disclosure can enhance absorption at approximately 200 nm. Therefore, it is desirable to select reducing melting conditions during glass production to a degree that results in lower transmittance at approximately 200 nm. This can be achieved, for example, by adding one or more reducing agents, such as sugars (reducing sugars, e.g., 0.2 to 0.6 wt.%), in a specific amount of 0.1 to 1.0 wt.-% (e.g., 0.2 to 0.6 wt.-%) during melting. However, the conditions should not be too reducing to avoid a high proportion of Fe. 2+ The material may have a negative impact on the transmittance at 220 nm.

[0064] In one aspect of the invention, when a glass melt is produced by inductively heating a glass in a platinum crucible to a temperature of 1500°C under an argon atmosphere, the oxygen partial pressure (pO2) in the glass melt at 1500°C is 0.5 bar or less. The pO2 at 1500°C can be, for example, at most 0.4 bar, at most 0.3 bar, or at most 0.2 bar. In some embodiments, the pO2 can be, for example, at least 0.01 bar, at least 0.02 bar, at least 0.05 bar, or at least 0.1 bar. The pO2 can be, for example, from 0.01 bar to 0.5 bar, from 0.02 bar to 0.4 bar, from 0.05 bar to 0.3 bar, or from 0.1 bar to 0.2 bar.

[0065] The pO2 of the glass melt can be determined, for example, based on the voltage between a reference electrode and a measuring electrode both located within the glass melt. pO2 can be calculated, for example, using the Nernst equation based on the voltage between the electrodes. A platinum plate can be used as the measuring electrode. The reference electrode may comprise a platinum wire positioned inside a ZrO2 ceramic tube closed at its tip, wherein the platinum wire is in conductive contact with the wall of the ZrO2 tube. The ZrO2 ceramic may be yttrium-stabilized, calcium-stabilized, or magnesium-stabilized (see, for example, EP 1 101 740A1, paragraphs

[0012] ,

[0013] ). To measure the pO2 of the glass melt, pure oxygen flows around the platinum wire, resulting in a constant pO2 of 1.0 bar at the platinum wire inside the reference electrode. ZrO2 is an oxygen conductor and forms a bridge between the platinum and the glass melt inside the reference electrode, and therefore indirectly also indirectly with the platinum measuring electrode inside the glass melt. Oxygen ion migration. The concentration cell generates a voltage of “platinum (pO2 = constant = 1.0 bar) / ZrO2 / glass melt / platinum (pO2 in glass melt)”. The voltage between the reference electrode and the measuring electrode is proportional to the pO2 in the glass melt, and can therefore be converted to determine the pO2 in the glass melt based on the Nernst equation.

[0066] In the examples, the Fe2O3 content is 1 ppm to 10 ppm, the TiO2 content is 2 ppm to 30 ppm, and the transmittance at 200 nm is less than 3%.

[0067] Therefore, in a preferred embodiment, the glass preferably has a total contamination of less than 20 ppm for all impurities of Pt, TiO2, and / or Fe2O3, less than 18.5 ppm in another embodiment, less than 13.5 ppm or less than 10.5 ppm in yet another embodiment. In other embodiments, the glass preferably has a total contamination of Pt, TiO2, and / or Fe2O3 between 1 and 20 ppm, between 1.5 and 18.5 ppm, between 2.0 and 13.5 ppm, or between 2.5 and 12.0 ppm. In yet another embodiment, the glass is free from contamination of at least one of the impurities selected from Pt, TiO2, and / or Fe2O3.

[0068] Other contaminants containing transition elements and / or heavy metals (such as lead, rhodium, cadmium, mercury, and hexavalent chromium) may also be kept below 10 ppm, and in another embodiment below 8.5 ppm. In other embodiments, these contaminants may be kept between 0 and 8.2 ppm, between 0 and 7.0 ppm, between 0 and 6.0 ppm, between 0 and 5.0 ppm, or between 0 and 4.0 ppm. In other embodiments, the levels of these contaminants may be between 0 and 3.0 ppm, between 0 and 2.0 ppm, between 0 and 1.0 ppm, between 0 and 0.5 ppm, or between 0 and 0.25 ppm. In another embodiment, the glass is free of any transition metal and / or heavy metal contaminants.

[0069] When a chemical element is mentioned in this document, it refers to any chemical form unless otherwise stated in individual cases. For example, the statement that the As content of glass is less than 100 ppm means that the sum of the mass fractions of the As substances present (e.g., As₂O₃, As₂O₅, etc.) does not exceed 100 ppm.

[0070] As used herein, the term “ppm” refers to parts per million (w / w) on a weight-to-weight basis.

[0071] Metal contamination during the production process needs to be avoided in order to produce glass with suitable UV transmittance. Therefore, the present invention can also relate to a method for producing glass with high UV transmittance.

[0072] In one embodiment, the glass of the present invention is a glass having high UV transmittance and the following additional range of physical and chemical parameters.

[0073] Unlike quartz, the glass of this invention possesses excellent melting properties, such as a low transition temperature and operating point. Examples of suitable glass parameters can be selected from those with a transition temperature Ttransition. g(ISO 7884-8) Below 550°C (e.g., 400°C to 500°C), in one embodiment between 440°C and 480°C, and in another embodiment between 450°C and 470°C.

[0074] glass T 13 Temperature (i.e., viscosity η in dPa*s is 10) 13 The annealing temperature (ISO 7884-4) of the glass can be between 410°C and 550°C, such as between 455°C and 495°C in one embodiment and between 460°C and 490°C in another embodiment. The softening point of the glass (i.e., the viscosity at 10⁻⁶) is also considered. 7.6 The temperature at dPa*s (softening point) (ISO 7884-3) can be between 630°C and 720°C, such as between 640°C and 700°C in one embodiment and between 650°C and 690°C in another embodiment. The operating point of the glass (i.e., having a viscosity of 10...) 4 The temperature (operating point) at dPa*s (ISO 7884-2) can be between 900°C and 1150°C, such as between 950°C and 1100°C in one embodiment, and between 975°C and 1050°C in another embodiment. The temperature-viscosity dependence represented by one or more of these parameters is consistent with the ability of the glass to be stretched or otherwise shaped into any desired shape, including UV lamp covers and UV-LED covers.

[0075] The density ρ of the glass of the present invention at 25°C can be between 2.3 and 2.7 g*cm³. -3 Between or between 2.4 and 2.6 g*cm -3 Between, for example, below 2.55g*cm -3 The low density makes the glass ideal for mobile applications, such as mobile pathogen eradication equipment.

[0076] The glass of the present invention is characterized by a thermal conductivity λ at 90°C. w Between 0.8 and 1.2 W*m -1 *K -1 Between or between 0.9 and 1.1 W*m -1 *K -1 This makes it ideal for use as a lamp cover.

[0077] UVC glass and UVC glass covers made therefrom have the following additional features:

[0078] The glass of this invention is characterized by its exceptionally high resistance to sunlight. This resistance can be determined by irradiating the glass with a HOK 4 lamp for 144 hours and comparing the transmittance at a wavelength of 220 nm before and after irradiation. The term "HOK 4 lamp" refers to the Philips HOK 4 / 120 high-pressure mercury vapor lamp. The emission spectrum of the HOK 4 lamp is shown in... Figure 4 The lamp's primary emission wavelength is 365 nm. At a distance of 1 m, the power density in the 200-280 nm range is 850 μW / cm². 2 To conduct the 144-hour irradiation of this invention, the distance between the HOK 4 lamp and the sample was chosen to be 7 cm.

[0079] The lower the difference in transmittance before and after irradiation, the higher the sun resistance. High sun resistance is associated with low sun exposure, and vice versa. High sun exposure is associated with high induced extinction (Ext). ind Related.

[0080] Induced extinction Ext ind The following formula can be used to determine the transmittance before and after 144 hours of irradiation with a HOK 4 lamp, as well as the thickness of the glass sample:

[0081]

[0082] Ext ind It is induced extinction, T 后 The transmittance, T, is obtained after 144 hours of irradiation with a HOK 4 lamp. 前 The transmittance is given after 144 hours of irradiation with a HOK 4 lamp, where d is the sample thickness and ln is the natural logarithm. Unless otherwise specified, the sample thickness d is given in cm, such that the induced extinction is given in 1 / cm. Unless otherwise specified, the transmittance before and after irradiation with a HOK 4 lamp is given for a wavelength of 220 nm. Therefore, unless otherwise specified, the induced extinction described in this disclosure refers to the induced extinction at a wavelength of 220 nm.

[0083] On the one hand, the induced extinction at a wavelength of 220 nm is at most 1.0 / cm, at most 0.5 / cm, at most 0.2 / cm, at most 0.1 / cm, at most 0.05 / cm, at most 0.02 / cm, or at most 0.01 / cm. The induced extinction at a wavelength of 220 nm can, for example, be at least 0.001 / cm, at least 0.002 / cm, or at least 0.005 / cm. The induced extinction at a wavelength of 220 nm can, for example, be from 0.001 / cm to 1.0 / cm, 0.001 / cm to 0.5 / cm, 0.002 / cm to 0.2 / cm, 0.002 / cm to 0.1 / cm, 0.002 / cm to 0.05 / cm, 0.005 / cm to 0.02 / cm, or 0.005 / cm to 0.01 / cm.

[0084] After irradiation with a HOK 4 lamp for 144 hours, the transmittance at a wavelength of 220 nm (with a reference thickness of 0.71 mm) can be, for example, at least 30%, at least 35%, at least 40%, or at least 60%.

[0085] After irradiation with a HOK 4 lamp for 144 hours, the transmittance at a wavelength of 220 nm (with a reference thickness of 0.71 mm) can be, for example, up to 95.0%, up to 90.0%, up to 85.0%, or up to 80.0%. The range of transmittance at a wavelength of 220 nm can be, for example, 30.0% to 95.0%, 35.0% to 90.0%, 40.0% to 85.0%, or 60.0% to 80.0%.

[0086] Due to the properties of glass, UVC glass covers can be hermetically sealed, for example, by using laser-sealed glass frit. This hermetically sealed seal is important because many UVGI applications are conducted in aqueous environments (e.g., biofilm treatments or water treatment), humid environments (e.g., wastewater systems), and / or environments with increased gas pressure or under vacuum. Furthermore, the hermetically sealed seal allows for high-pressure treatment of the final device (e.g., a UVC-LED lamp), enabling its use in hospitals, operating rooms, laboratories, or any other environment requiring high hygiene standards.

[0087] This contrasts with conventional glass, quartz, and / or fused silica glass, which lack the thermal properties required for laser frit sealing and therefore cannot achieve hermetic seals. However, the glass described herein is suitable for achieving crack-free and tight glass frit connections.

[0088] The glass of the present invention preferably has a product CTE[°C] of at most 0.01, more preferably at most 0.0099 or at most 0.0098. -1]×T4[℃]. The product can be at least 0.0075 or at least 0.0085. It has been shown that these glasses exhibit favorable properties in terms of melting stress and melting behavior.

[0089] "T4" indicates that the viscosity of the glass is 10. 4 The temperature at which dPa*s is measured. T4 can be measured using methods known to those skilled in the art for determining glass viscosity (e.g., according to DIN ISO 7884-1:1998-02). 13 "The viscosity of the glass is 10." 13 Temperature at dPa*s.

[0090] The average linear coefficient of thermal expansion α (CTE) (at 20°C; 300°C, according to ISO 7991) in one embodiment is between 7.0 and 12.0 × 10⁻¹⁰. -6 K -1 Between. The coefficient of thermal expansion (CTE) can be less than 11.5*10. -6 K -1 Its range can be from 7.5 to <11*10. -6 K -1 More preferably 8.75 to 10.75*10 -6 K -1 More preferably 9.0 to 10.0*10 -6 K -1 More preferably 9.2 to 9.8*10 -6 K -1 This allows the thermal expansion properties to be adapted to the overall thermal expansion properties of the UV device, thereby preventing tension within the glass cover. In one embodiment, the same or similar CTE is selected for both the UVC glass cover and the underlying UV device (e.g., a UVC-LED package).

[0091] Another important property of glass is its refractive index n. d Excellent spatial uniformity. Optionally, the refractive index change within the glass can correspond to the deformation of the wavefront passing through the glass, according to the following formula:

[0092] Δs=Δ(n d *d)=Δn d *d+Δd*n d

[0093] Where Δs is the wavefront deviation, d is the glass thickness, Δd is the thickness variation (the difference between the maximum and minimum thickness), and Δn d It refers to the change in refractive index in the glass (the difference between the maximum and minimum refractive index). The invention further includes glass articles having the indicated wavefront deviation.

[0094] Wavefront deviation can be calculated using the formula above. Refractive index n d (λ = 587.6 nm) and thickness can be determined at 20°C. In one embodiment, at 1 cm 2 The wavefront deviation is determined on the surface area and / or applied to the surface area. The wavefront deviation can be determined for a glass thickness of 10 mm or less, or a glass thickness of 1 mm or less. Optionally, the thickness can be at least 200 μm. The wavefront deviation can be less than ±0.1 mm, less than ±0.08 mm, and in other embodiments less than ±0.035 mm, less than ±25 μm, less than ±15 μm, or less than ±5 μm. Optionally, the wavefront deviation can be between 0.1 μm and 250 μm, between 1 μm and 100 μm, or between 2 μm and 85 μm.

[0095] Wavefront deviation can be measured axially (e.g., in the case of a glass tube, such as in a discharge lamp) or laterally (e.g., in the case of a rod section, such as a lens in a UVC-LED).

[0096] Wavefronts can also be measured using wavefront sensors. These wavefront sensors are devices that measure wavefront aberrations in coherent signals used to describe the optical quality or deficiencies of an optical system. Not bound by any particular method, a very common approach is to use a Shack-Hartmann microlens array.

[0097] Alternative wavefront sensing techniques to the Shaker-Hartmann system are mathematical techniques, such as phase imaging or curvature sensing. These algorithms calculate wavefront images from conventional bright-field images at different focal planes without requiring specialized wavefront optics.

[0098] The glass and glass articles according to the present invention can have low levels of wavefront deformation (stripes, bubbles, streaks, etc.) in the glass. Generally, the global or long-range homogeneity of the refractive index of the material and short-range deviations from the glass homogeneity can be distinguished. Streaks are short-range spatial variations in the glass homogeneity. Short-range variations are changes over distances of approximately 0.1 mm to up to 2 mm, while the long-range global homogeneity of the refractive index covers the entire glass piece.

[0099] In some embodiments, an ultraviolet transmission filter can be used to filter out certain undesired UV wavelengths (e.g., wavelengths above 220 nm).

[0100] The glass for UV covers according to the invention allows for lens shaping to optically shape UV beams, for example, for directional focusing of UV light onto a target.

[0101] Any beam angle between 10° and 180° is acceptable. In some embodiments, 10° to 20°, 20° to 30°, 30° to 40°, 40° to 50°, 50° to 60°, 60° to 70°, 70° to 80°, and 80° to 90° can be used. In other embodiments, 15° to 35°, 25° to 45°, 35° to 60°, 45° to 90°, 75° to 120°, 90° to 145°, and 120° to 180° can be used.

[0102] In some embodiments, a fairly wide beam shape (such as 90°, 120° or even 180°) is useful (e.g., when it is necessary to decontaminate a surface of a certain size or volume or a tube of a certain diameter in a single process).

[0103] In other embodiments, narrow beam shapes (such as 10°, 5°, or even 1°) are useful. For example, narrow beam shapes can be used to focus UV exposure on a target area and avoid non-directional and undesirable radiation that would result in a less efficient energy-to-radiation ratio or exposure of UV-sensitive surfaces to UV light. One example could be limited decontamination of a defined area of ​​the eye.

[0104] Furthermore, different lens shapes and beam angles can be used to address complex pathogen eradication tasks. For example, in situations where UV-sensitive surfaces of varying sensitivity levels are adjacent to each other and require UV exposure in a single treatment. For instance, it may be appropriate to treat a patient's skin in some areas with higher UV exposure than neighboring areas (e.g., during wound treatment and / or surgery, where the wound itself is exposed to less UV than the surrounding skin).

[0105] The present invention also includes a method for producing an LED package having a cap made of the 220nm-UVC transmissive glass of the present invention.

[0106] The LED package according to the present invention may include

[0107] LED chips;

[0108] • Optional: A substrate on which LED chips are mounted – for example, made of PCB, polymer, inorganic materials, especially ceramic, or metal;

[0109] • Optional: A base plate in the housing, including feedthroughs (metal, ceramic, glass-ceramic, polymer) for contacting the electrical conductors of the LED chip;

[0110] • A frame (metal, ceramic, glass-ceramic, polymer) containing LED chips that is attached to or surrounds a base plate and forms a cavity;

[0111] • The distal portion of the housing (cover) is located away from and at a certain distance from the chip, and the distal portion of the housing is at least partially translucent, encloses the package, or is entirely made of a translucent material; wherein at least the translucent portion of the cover is made of UVC translucent glass as described herein.

[0112] Such a window can be flat or have a shape that alters the path of light (i.e., a lens shape).

[0113] As mentioned earlier, UVC-LEDs can be encapsulated and sealed (e.g., laser-fused) to make them heat-processable, sterilizable, and resistant to fluids. Such UVC-LEDs can be used for air and water sterilization, surface sterilization, and in medical / dental applications.

[0114] UVC-LEDs with UVC-transmissive glass as described herein have additional advantages over conventional UVGI lamps or devices (such as mercury vapor lamps), for example:

[0115] • Instant on / off function, which allows for "disinfection on demand" without wasting energy;

[0116] • Directional emission (especially by using lenses that allow control of the beam angle, which allows for “targeted sterilization” with a simple design);

[0117] • Semiconductor durability, which allows for use in rugged portable devices;

[0118] • Low DC power requirements, which increases energy efficiency and results in simple and inexpensive electric drives;

[0119] • Compact packaging, which maximizes design flexibility;

[0120] • Environmentally friendly construction, as this allows for easy disposal without harmful mercury exposure;

[0121] High optical performance;

[0122] • High radiant power at a defined wavelength;

[0123] • Relatively low production cost;

[0124] Small size.

[0125] Traditionally, both low-pressure and medium-pressure mercury lamps have been used in sterilization systems. However, there is a need to replace these light sources with high-power and energy-efficient UV lamps (e.g., UVC-LEDs). The UV lamps and UV devices of this invention are more energy-efficient than conventional UVGI lamps or devices. This is because the glass can transmit more than 60% of UV light at 220 nm, and therefore, the ratio between energy input and radiation output is significantly improved.

[0126] This becomes important when using these glasses as UVC-LED lamp covers. If the energy requirement of a conventional mercury vapor UV lamp is set to 100%, the energy required to generate the same UV radiation using the UVC-LED described herein is approximately 10% to 30%. In other words, if a conventional UV lamp uses 10W of energy to emit a certain UV intensity, the device described herein can use only between 1W and 3W.

[0127] As mentioned earlier, another advantage of the UVC transmissive glass described in this article is its high thermal conductivity (λ). w The thermal conductivity at 90°C can be between 0.75 and 1.25 W / m. -1 *K -1 Between, in other embodiments approximately 1.0 W*m -1 *K -1 This superior thermal conductivity increases the lifespan of the equipment because excess heat can dissipate easily before damaging other parts of the device. This contrasts, for example, with quartz glass, which typically has less than ideal thermal conductivity.

[0128] Therefore, in one embodiment, the method according to the invention may include UV lamps with an energy efficiency index (EEI) ≤0.11 according to EU Regulation (REGULATION) No. 874 / 2012 in the case of non-directional UV lamps and an energy efficiency index (EEI) ≤0.13 according to EU Regulation (REGULATION) No. 874 / 2012 in the case of directional UV lamps.

[0129] The methods described herein can be used to eradicate pathogens from any type of surface, including UV-sensitive surfaces, UV-sensitive liquids, and / or UV-sensitive gases.

[0130] Of course, the methods described in this article can also be used to eradicate various UV-sensitive pathogenic organisms, such as viruses (e.g., influenza or coronaviruses, such as SARS-CoV-2, especially drug-resistant viral mutations, such as SARS-CoV2-D614G), bacteria (including spores), pathogenic yeasts, molds, and so on.

[0131] Potential applications may be selected from the following list of uses: hand sanitizers (e.g., in private and public toilets), room disinfectants in healthcare settings, pathogen eradication during or after surgical preparation, surgery, wound care, eye care, food disinfection (e.g., during food production and / or meat, dairy, or vegetable counters in supermarkets), livestock disinfection (especially in the case of intensive livestock farming, such as multi-layered laying hen cages), production of pharmaceutical compounds and / or food production processes, storage facilities, and / or disinfection of UV-sensitive surfaces that are frequently exposed to many different users (e.g., keyboards, handles, armrests, toothbrushes, hairbrushes, decorations, touch devices, razors, or children's toys).

[0132] The UVC device disclosed in this invention can also be used in a wide range of applications as an "analytical instrument," for example:

[0133] • HPLC (High Performance Liquid Chromatography): Used in analysis for the detection of chemicals and compounds in the life sciences; • Spectrometers: Used in multiple applications for testing and analysis across biotechnology, life sciences, and environmental monitoring; and

[0134] • Water quality monitoring sensors: used to detect chemicals in water (e.g., during hydraulic fracturing, under general water safety conditions, or before the treatment of wastewater).

[0135] In another embodiment, the UVC device disclosed in this invention may include a device for "water disinfection." In that respect, UVC LEDs are advantageous compared to conventional mercury lamps, which require a longer preheating time (50 seconds to 10 minutes everywhere) to reach the desired sterilization intensity. Additionally, frequent on / off cycles can reduce lifespan by 50% or more.

[0136] Therefore, mercury lamps in these applications need to be kept on all day, increasing lamp replacement frequency, ozone generation, and power consumption. In contrast, UVC LEDs' instant on-off capability enables sterilization on demand, which significantly reduces power consumption. Furthermore, frequent on / off cycles do not reduce LED lifespan, thus helping to lower operating and maintenance costs.

[0137] Further uses of the UVC device disclosed in this invention (especially in the case of UV-sensitive surfaces, liquids, or gases) may include:

[0138] • Protein analysis, namely, bioinformatics research on protein structure and function using database retrieval, sequence comparison, structure and function prediction.

[0139] Molecular identification is the process of comparing specific DNA fragments between organisms.

[0140] • Cell counting, or flow cytometry in biotechnology, is a laser- or impedance-based biophysical technique used in cell counting, cell sorting, biomarker detection, and protein engineering by suspending cells in a fluid flow and passing them through an electronic detection device.

[0141] • Biofilm treatment systems are systems that utilize bacteria, fungi, algae, and protozoa for the purpose of removing organic and inorganic materials from surrounding fluids.

[0142] • Nitrate and / or NOx measurements, typically performed at a wavelength of approximately 230 nm.

[0143] • Skin treatments to improve dermatological conditions (e.g., psoriasis, vitiligo, pruritus, neurodermatitis, acne, actinic dermatitis, phototherapy, pityriasis rosea, etc.).

[0144] Therefore, in one embodiment, the use of the UV-LED module can be selected from the group consisting of: water disinfection, analytical instruments (HPLC, spectrometer, water monitoring sensor), air purification, air disinfection, surface disinfection (e.g., keyboard disinfection, escalator handrail UV sterilizer), cell counting, molecular identification, protein analysis, biofilm treatment, curing, photolithography, vegetable growth, skin treatment, pathogen detection, drug discovery, protein analysis, induction and / or sterilization of vitamin D3 production in the skin.

[0145] Therefore, in one aspect, the present invention relates to the use of glass as an airtight lens cap for a UV-LED module, for example for applications selected from the group consisting of: water disinfection, analytical instruments (HPLC, spectrometers, water monitoring sensors), air purification, air disinfection, surface disinfection (e.g., keyboard disinfection, escalator handrail UV sterilizers), cell counting, molecular identification, protein analysis, biofilm treatment, curing, photolithography, vegetable growth, skin treatment (psoriasis, vitiligo, pruritus, neurodermatitis, acne, actinic dermatitis, phototherapy, pityriasis rosea), pathogen detection, drug discovery, protein analysis, induction and / or sterilization of vitamin D3 production in the skin.

[0146] The glass is preferably soda-lime glass. In embodiments, the glass comprises the following components (in mol% by weight of oxides):

[0147] Components Content [mol%] <![CDATA[SiO2]]> 40 to 85 <![CDATA[Al2O3]]> 0 to 25 <![CDATA[Na2O]]> 0 to 18 <![CDATA[K2O]]> 0 to 15 MgO 0 to 10 <![CDATA[B2O3]]> 0.1 to 4 <![CDATA[Li2O]]> 0 to 10 ZnO 0 to 5 CaO 0 to 16 BaO 0 to 12 <![CDATA[ZrO2]]> 0 to 5 <![CDATA[SnO2]]> 0 to 3 SrO 0 to 4 <![CDATA[F - ]]> 0 to 6 <![CDATA[Cl - ]]> 0 to 1

[0148] In another embodiment, the glass comprises the following components (in mol% based on oxides):

[0149]

[0150]

[0151] "R2O" refers to alkali metal oxides Li2O, Na2O, and K2O; and "RO" refers to alkaline earth metal oxides MgO, CaO, BaO, and SrO.

[0152] Glass can contain at least 40 mol% or at least 60 mol% SiO2. SiO2 contributes to the glass's resistance to hydrolysis and its translucency. If the SiO2 content is too high, the glass's melting point will be too high. Temperatures T4 and T... g It also rises sharply. Therefore, the SiO2 content should be limited to a maximum of 78 mol%, or a maximum of 80 mol%, or a maximum of 81 mol%, or a maximum of 82 mol%, or a maximum of 85%.

[0153] Preferably, the SiO2 content is at least 61 mol%, at least 63 mol%, at least 65 mol%, at least 68 mol%, at least 69 mol%, at least 70 mol%, at least 72 mol%, or at least 75 mol%. The content may be limited to a maximum of 84 mol%, at most 82 mol%, at most 81 mol%, or at most 80 mol%.

[0154] The maximum percentage of Al2O3 that can be contained in glass is 10 mol%. Al2O3 contributes to the phase separation stability of glass, but a higher percentage will reduce acid resistance. Furthermore, Al2O3 increases the melting temperature and T4. Therefore, the content of this component should be limited to a maximum of 25 mol%, or a maximum of 9 mol%, or a maximum of 8 mol%, or a maximum of 7 mol%, or a maximum of 5 mol%, or a maximum of 4.5 mol%. In some embodiments, a smaller percentage of Al2O3 is used: at least 0.1 mol%, at least 0.2 mol%, or at least 0.5 mol%, or at least 1.0 mol%. In some embodiments, the glass may be Al2O3-free.

[0155] The glass may contain at least 0.5 mol% B₂O₃. B₂O₃ affects the melting properties of glass. The B₂O₃ content may be limited to up to 4.0 mol%, up to 3.5 mol%, up to 3.0 mol%, up to 2.5 mol%, or up to 2.0 mol%. Limiting the amount of B₂O₃ is beneficial for reducing transmittance at 200 nm. The B₂O₃ content may be at least 1.0 mol%, at least 1.2 mol%, or at least 1.5 mol%.

[0156] Optionally, the ratio of the sum of the mol% contents of B2O3, R2O, and RO to the sum of the mol% contents of SiO2 and Al2O3 is at most 0.4, at most 0.35, or at most 0.3. In one embodiment, this value is at least 0.1, at least 0.15, or at least 0.2.

[0157] The glass may contain up to 10.0 mol%, up to 3.0 mol%, up to 2.8 mol%, or up to 2.5 mol% of Li₂O. Optionally, the glass may contain only a small amount of Li₂O, such as up to 3.0 mol%, up to 2.8 mol%, up to 2.5 mol%, up to 2.0 mol%, or up to 1.9 mol%, or the glass may contain no Li₂O. In some embodiments, the Li₂O content is between 1 mol% and 2 mol%.

[0158] The glass may contain up to 18 mol%, 15 mol%, 12 mol%, 11 mol%, or 10 mol% Na₂O. Na₂O increases the fusibility of the glass. Sodium oxide also leads to decreased UV transmittance and an increased coefficient of thermal expansion (CTE). The glass may contain at least 1 mol%, at least 2 mol%, at least 4 mol%, at least 5 mol%, or at least 6 mol% Na₂O. In one version, the Na₂O content is up to 5 mol% or up to 4 mol%. In some embodiments, the glass may be Na₂O-free.

[0159] The glass may contain a maximum of 15 mol% of K2O. Its content may be at least 1 mol%, at least 2 mol%, at least 4 mol%, at least 5 mol%, or at least 6 mol%. The content of this component may be limited to a maximum of 15 mol%, a maximum of 12 mol%, a maximum of 10 mol%, a maximum of 9 mol%, or a maximum of 8 mol%. In some embodiments, the glass may be K2O-free.

[0160] In embodiments, the mol% ratio of Na₂O to K₂O can be at least 1.0, particularly at least 1.1. In embodiments of the invention, the ratio is at most 2, specifically at most 1.5. These two oxides are used to improve the fusibility of the glass. In some embodiments, the ratio is between 1.1 and 1.3.

[0161] The amount of R2O in the glass may be limited to no more than 25 mol%, no more than 22 mol%, or no more than 20 mol%. The glass may contain at least 5 mol%, at least 8 mol%, or at least 10 mol% of R2O. In some embodiments, the R2O content is between 10 mol% and 20 mol%. R2O can help reduce transmittance at 200 nm.

[0162] Glass can contain up to 10 mol%, 6 mol%, 4 mol%, or 2 mol% of MgO. MgO is beneficial for solubility, but at high proportions, it has proven problematic for desired UV transmittance and phase separation tendency. Preferred designs are MgO-free.

[0163] Glasses can contain up to 16 mol%, 6 mol%, 4 mol%, 2 mol%, or 1 mol% CaO. CaO is beneficial for fusibility, but at high proportions, the desired UV transmittance becomes problematic. Preferred forms contain no CaO or only very little CaO, such as at least 0.1 mol%, at least 0.3 mol%, or at least 0.5 mol%.

[0164] Glass can contain up to 4 mol%, 1 mol%, or 0.5 mol% SrO. While SrO is beneficial for fusibility, at high proportions, the desired UV transmittance becomes problematic. Preferred designs are SrO-free.

[0165] The glass may contain up to 12 mol%, 8 mol%, 6 mol%, 5 mol%, or 4 mol% BaO. BaO contributes to improved hydrolysis resistance. However, excessively high barium oxide content leads to phase separation and therefore makes the glass unstable. Preferred embodiments contain at least 0.5 mol%, at least 1.0 mol%, or at least 1.5 mol% BaO. In some embodiments, the BaO content is between 1.0 mol% and 4.0 mol%. In some embodiments, the glass may be BaO-free.

[0166] It has been shown that alkaline earth oxides (RO) have a significant influence on phase separation tendency. Therefore, in the design form, particular attention is paid to the content of these components and their relationship to each other. Thus, the ratio of the mol% of BaO to the sum of the mol% contents of MgO, SrO, and CaO can be at least 2. Optionally, this value is at least 5, at least 10, or at least 20. In a particularly preferred form, the value can be at least 40 or even at least 50. Compared to other alkaline earth metal oxides, BaO offers the greatest advantages in terms of phase separation and hydrolysis resistance. However, the ratio should not exceed 120 or 100. In an advantageous form, the glass contains at least a small amount of CaO and BaO, and is free of MgO and SrO. In some embodiments, the ratio is between 50 and 100.

[0167] Specifically, advantageous properties are obtained if the mol% ratio of CaO to BaO in the glass is less than 0.2. Specifically, this ratio can be less than 0.15 or less than 0.1. In some embodiments, the ratio is even lower, specifically less than 0.08 or less than 0.06, and in a preferred design, this ratio is at least 0.03. In some embodiments, the ratio is between 0 and 0.1.

[0168] In one version, the mol% ratio of B2O3 to BaO in the glass is at least 0.1 and at most 2.0. Preferably, the ratio is at least 0.2 or at least 0.5, and in a preferred design, the ratio is limited to a maximum of 1.8, 1.5, or 1.2. In another embodiment, the ratio may be limited to a maximum of 1.0 or 0.8. Specifically, the ratio is not less than 0.2 and not more than 2.0; or in another embodiment, not less than 0.5 and not more than 1.8; in some embodiments, the ratio is between 0.2 and 1.0.

[0169] The RO content in the glass of the present invention can be at least 0.3 mol%. Alkali earth metal oxides are beneficial for fusibility, but at high proportions, the desired UV transmittance has proven problematic. In one version, the glass contains up to 5 mol% RO. In one embodiment, the RO content is between 1 mol% and 5 mol%.

[0170] The sum of the mol% content of alkaline earth metal oxides and alkali metal oxides RO + R2O can be limited to a maximum of 30 mol%. An advantageous design may contain these components in amounts up to 25 mol%. Preferably, the content of these oxides is at least 5 mol%, at least 10 mol%, or at least 12 mol%. In one embodiment, the RO + R2O ratio is between 12 mol% and 20 mol%. Excessive proportions of these components increase the tendency for phase separation and reduce the glass's resistance to hydrolysis.

[0171] The ratio of the mol% content of B2O3 to the sum of the mol% contents of R2O and RO can be at least 0.01, at least 0.02, or at least 0.05. The ratio can be limited to a maximum of 1.5, a maximum of 1.0, or a maximum of 0.5. In one embodiment, the B2O3 / (RO+R2O) ratio is between 0.05 and 0.2. If too much alkali or alkaline earth oxide is present relative to B2O3, alkali or alkaline earth borates can form during glass phase separation. Adjusting the above ratio has proven advantageous.

[0172] To ensure melting properties (including T) g Within the desired range, it can be advantageous to set the ratio of B2O3 content to the sum of the mol% contents of SiO2 and Al2O3 within a narrow range. In an advantageous design, this ratio is at least 0.015 and / or at most 0.04. In one embodiment, the B2O3 / (SiO2+Al2O3) ratio is between 0.017 and 0.03.

[0173] The mol% ratio of the sum of alkali metal oxides R₂O to the sum of alkaline earth metal oxides RO is preferably >1, specifically >2 or >4. In the design form, this ratio is at most 15, at most 10 or at most 7.5. In one embodiment, the ratio is between 4 and 10.

[0174] Glass can contain F - The content is 0 to 6 mol%. Preferably, F - The content is at most 4 mol% or at most 2 mol%. In the design form, at least 0.5 mol% or at least 1 mol% of this component is used. Component F - It improves the glass's fusibility and influences the UV edge at smaller wavelengths.

[0175] Glass can contain Cl - The content is less than 1 mol%, especially less than 0.9 mol% or less than 0.8 mol%. A suitable lower limit is 0.1 mol% or 0.2 mol%.

[0176] The glass may contain less than 5 mol%, particularly less than 2.5 mol% or less than 1 mol% of ZnO. Suitable lower limits are 0.01 mol% or 0.05 mol%. In some embodiments, the glass may be free of ZnO.

[0177] The glass may contain less than 5 mol%, less than 2.5 mol%, or especially less than 1 mol% of ZrO2. Suitable lower limits are 0.01 mol% or 0.05 mol%. In some embodiments, the glass may be free of ZrO2.

[0178] The glass may contain less than 3 mol%, particularly less than 2 mol% or less than 1 mol% of SnO2. Suitable lower limits are 0.01 mol% or 0.05 mol%. In some embodiments, the glass may be SnO2-free.

[0179] When this specification states that the glass is free of a component or does not contain a certain component, it means that the component may be present at most as an impurity. This means that the component is not added in a significant amount. A non-significant amount is less than 0.5 ppm, preferably less than 0.25 ppm, preferably less than 0.125 ppm, and most preferably less than 0.05 ppm.

[0180] In one embodiment, the glass contains less than 10 ppm of Fe₂O₃, specifically less than 5 ppm or less than 4 ppm. In one embodiment, the glass contains less than 10 ppm of TiO₂, particularly less than 5 ppm or less than 4 ppm. In one embodiment, the glass contains less than 3.5 ppm of arsenic, particularly less than 2.5 ppm or less than 1.0 ppm. Preferably, the glass contains less than 3.5 ppm of antimony, less than 2.5 ppm of antimony, or less than 1.0 ppm of antimony. Besides their negative effects on UV transmittance and sunlight exposure, arsenic and antimony are particularly toxic and harmful to the environment and should be avoided.

[0181] Optionally, the glass contains the following components (in mol% based on oxides):

[0182] Components Content [mol%] <![CDATA[SiO2]]> 68 to 82 <![CDATA[Al2O3]]> 0.1 to 7 <![CDATA[B2O3]]> Versions 1.0 to 3.0 <![CDATA[Li2O]]> 0 to 3.0 <![CDATA[Na2O]]> 1 to 12 <![CDATA[K2O]]> 1 to 10 CaO 0 to 4 SrO 0 to 1 BaO 0.5 to 6 <![CDATA[F - ]]> 0 to 6

[0183] In another form, glass comprises the following components (in mol%):

[0184] Components Content [mol%] <![CDATA[SiO2]]> 69 to 81 <![CDATA[Al2O3]]> 0.2 to 5 <![CDATA[B2O3]]> 1.2 to 2.5 <![CDATA[Li2O]]> 0 to 2.5 <![CDATA[Na2O]]> 2 to 11 <![CDATA[K2O]]> 2 to 9 CaO 0 to 2 SrO 0 to 0.5 BaO 1.0 to 5 <![CDATA[F - ]]> 0.5 to 4

[0185] In another form, glass comprises the following components (in mol%):

[0186]

[0187]

[0188] The present invention also includes glass articles made from the glass described herein. These glass articles can be produced using drawing processes known for glass tubes and rods. Depending on the desired shape, those skilled in the art will select a suitable manufacturing process, such as casting to obtain rods, float glass, or downdrawing to produce glass sheets. Preferably, the cooling of the glass during the process is adjusted to obtain the desired properties.

[0189] In one embodiment, the Dana process or Vero process is used to produce glass articles. In the Vero process, the molten glass flows vertically downward (along the direction of gravity) through a forming tool made of an outlet ring and needles. The forming tool forms a negative shape (matrix) of the resulting cross-section of the glass tube or glass rod. In the manufacture of the glass tube, the needles are arranged as forming parts at the center of the forming tool.

[0190] The difference between the Verlo process and the downdraw process lies firstly in the fact that in the Verlo process, the molten glass deflects horizontally after leaving the forming tool, and secondly in the fact that the needle in the Verlo process has a channel through which blown air flows. As with the Dana process, the blown air ensures that the resulting glass tube does not collapse. In the downdraw process, the solidified molten glass is separated without prior redirection. Because there is no redirection, the use of blown air can also be avoided during the production of the glass tube.

[0191] In this embodiment, the present invention relates to a glass article made of the glass disclosed herein. The thickness of the glass article (specifically, in the case of a glass tube, the wall thickness) can be at least 0.1 mm or at least 0.3 mm. The thickness can be limited to up to 3 mm or up to 2 mm. The outer diameter of the glass article (e.g., the outer diameter of a glass tube or glass rod) can be up to 50 mm, up to 40 mm, or up to 30 mm. The outer diameter can specifically be at least 1 mm, at least 2 mm, or at least 3 mm.

[0192] Therefore, the present invention also relates to the following embodiments:

[0193] In one aspect, the present invention relates to a method for eradicating pathogens, the method comprising exposing the pathogens to bactericidal UV light of a wavelength of about 220 nm, wherein the UV light is irradiated by a UV lamp having a lamp cover made of glass having a total platinum content of less than 3.5 ppm.

[0194] On the other hand, the pathogens exposed to bactericidal UV light reside on a UV-sensitive material that is sensitive to UV radiation above 222 nm. In yet another aspect, the UV-sensitive material is the surface of an animal's biological tissue, such as the eye or skin, wherein the animal is selected from insects, invertebrates, vertebrates, mammals, and / or humans.

[0195] On the other hand, according to BS ISO 22196:2011-08-31, the eradication rate of the pathogen after treatment is >99%.

[0196] On the other hand, the UV exposure of the pathogen was at least 2000 to 8000 microwatts per square centimeter (μW·s / cm²). 2 Within the range of ).

[0197] In another aspect, all or part of the cover of the UV lamp is formed in the form of a lens.

[0198] In another aspect, the present invention relates to a glass with a transmittance of at least 30% at a wavelength of 220 nm, wherein the total platinum content of the glass is not more than 3.5 ppm, and in some embodiments not more than 3 ppm, not more than 2.5 ppm, or not more than 2 ppm.

[0199] For many applications, a certain transmittance in the UV range is desirable. The ratio of the glass's transmittance at 220 nm to its transmittance at 200 nm can be at least 20.00 or at least 30.00, particularly at most 100.00 or at most 80.00.

[0200] In another aspect, the glass includes one or more UV-blocking impurities selected from the group consisting of rhodium, lead, cadmium, mercury, hexavalent chromium, iron, titanium, and any combination thereof. In yet another aspect, the glass contains less than 1.0 ppm of total platinum.

[0201] Wavefront deviation can be less than ±0.1 mm, less than ±0.08 mm, and in other embodiments less than ±0.035 mm, less than ±25 μm, less than ±15 μm, or less than ±5 μm. Optionally, wavefront deviation can be between 0.1 μm and 250 μm, between 1 μm and 100 μm, or between 2 μm and 85 μm. In another aspect, the glass comprises the following components in indicated amounts (in mol%):

[0202]

[0203]

[0204] On the other hand, the present invention relates to the use of the glass as an airtight lens cap for a UV-LED module, for example for applications selected from the group consisting of: water disinfection, analytical instruments (HPLC, spectrometers, water monitoring sensors), air purification, air disinfection, surface disinfection (e.g., keyboard disinfection, escalator handrail UV sterilizers), cell counting, molecular identification, protein analysis, biofilm treatment, curing, photolithography, vegetable growth, skin treatment (psoriasis, vitiligo, pruritus, neurodermatitis, acne, actinic dermatitis, phototherapy, pityriasis rosea), pathogen detection, drug discovery, protein analysis, induction and / or sterilization of skin vitamin D3 production.

[0205] In one aspect, the present invention relates to a glass article comprising or composed of the glass described herein. In one embodiment, the glass article has at least one polished surface. Optionally, the glass article has at least one chamfered edge. The surface roughness Ra of the polished surface is less than 10 nm or less than 5 nm. The chamfered edge is more impact-resistant than the non-chamfered edge, specifically more resistant to chipping.

[0206] Heat tempering and / or chemical tempering

[0207] Optionally, the manufacturing process includes chemical and / or thermal tempering steps for the glass article. "Tempering" is also known as "hardening".

[0208] Preferably, the glass article is tempered on at least one surface, specifically by thermal tempering and / or chemical tempering. For example, the glass article can be chemically tempered by ion exchange. In this process, small alkali ions in the article are typically replaced by larger alkali ions. Smaller sodium ions are often replaced by potassium ions. However, very small lithium ions can be replaced by sodium and / or potassium ions. Optionally, alkali ions can be replaced by silver ions. Another possibility is to exchange alkaline earth ions with each other based on the same principle as alkali ions. Preferably, the ion exchange is carried out in a molten salt bath between the article surface and the salt bath. Pure molten salt (e.g., molten KNO3) can be used for the exchange. However, salt mixtures or mixtures of salt with other components can also be used. The mechanical resistance of the article can be further increased if a selectively tuned compressive stress profile is established within the article. This can be achieved through a single-stage or multi-stage ion exchange process.

[0209] Compressive stress is generated in the corresponding region by replacing small ions with large ions or by heat tempering, and this compressive stress decreases from the surface of the glass article towards the center. The maximum compressive stress is just below the glass surface and is also referred to as CS (compressive stress). CS is stress and is expressed in MPa. The depth of the compressive stress layer is abbreviated as "DoL" and given in μm. Preferably, CS and DoL are measured using an FSM-60LE device from Orihara.

[0210] In one embodiment, CS is greater than 100 MPa. More preferably, CS is at least 200 MPa, at least 250 MPa, or at least 300 MPa. More preferably, CS is at most 1000 MPa, at most 800 MPa, at most 600 MPa, or at most 500 MPa. Preferably, the range of CS is >100 MPa to 1000 MPa, 200 MPa to 800 MPa, 250 MPa to 600 MPa, or 300 MPa to 500 MPa.

[0211] In one embodiment, the glass article is heat-tempered. Heat tempering is typically achieved by rapidly cooling the hot glass surface. The advantage of heat tempering is that the compressive stress layer can be formed deeper (DoL) than with chemical tempering. This makes the glass less prone to scratches because the compressive stress layer is not as easily penetrated by scratches as a thinner compressive stress layer.

[0212] Glass or glass articles may undergo a heat tempering process, for example, after melting, forming, annealing / cooling, and cold post-treatment steps. During this process, the glass body (e.g., the previously described glass articles or preliminary products) (e.g., flat glass) is preferably fed horizontally or suspended in the equipment and rapidly heated to above the transformation temperature T. GTemperatures can reach up to 150°C. The surface of the glass body is then rapidly cooled (e.g., by blowing cold air through a nozzle system). Due to the rapid cooling of the glass surface, it freezes into an expanded network, while the interior of the glass body cools slowly and has time to contract further. This generates compressive stress in the surface layer and tensile stress in the interior. The amount of compressive stress depends on various glass parameters, such as CTE. 玻璃 (Average linear thermal expansion coefficient below Tg), CTE 液体 The average linear thermal expansion coefficient (above Tg), strain point, softening point, Young's modulus, and also depend on the amount of heat transfer between the cooling medium and the glass surface and the thickness of the glass body.

[0213] Preferably, a compressive stress of at least 50 MPa is generated. Therefore, the flexural strength of the glass body can be doubled or tripled compared to untempered glass. In an embodiment, the glass is heated to a temperature of 750°C to 800°C and rapidly tempered in a stream of cold air. Optionally, the blowing pressure can be from 1 to 16 kPa. Using the glass or glass articles described herein, compressive stress values ​​obtained on commercially available systems are, for example, from 50 to 250 MPa, specifically from 75 to 200 MPa.

[0214] In one embodiment, the compressive stress of the compressive stress layer in the glass article is at least 50 MPa, particularly at least 75 MPa, at least 85 MPa, or at least 100 MPa. The glass article may have a compressive stress layer on one, two, or all of its surfaces. The compressive stress of the compressive stress layer may be limited to at most 250 MPa, at most 200 MPa, at most 160 MPa, or at most 140 MPa. These compressive stress values ​​may specifically exist in heat-tempered glass articles.

[0215] In one embodiment, the depth of the compressive stress layer of the glass article is at least 10 μm, at least 20 μm, at least 30 μm, or at least 50 μm. In some embodiments, this layer may even be at least 80 μm, at least 100 μm, or at least 150 μm. Optionally, the DoL is limited to at most 2000 μm, at most 1500 μm, at most 1250 μm, or at most 1000 μm. In particular, the DoL can be from 10 μm to 2000 μm, from 20 μm to 1500 μm, or from 30 μm to 1250 μm. In one embodiment, the glass article is heat-tempered with a DoL of at least 300 μm, at least 400 μm, or at least 500 μm. Optionally, the DoL can be at most 2000 μm, at most 1500 μm, or at most 1250 μm. In one embodiment, DoL is 300 μm to 2000 μm, 400 μm to 1500 μm, or 500 μm to 1250 μm.

[0216] Example

[0217] Alkali-containing silicate glasses having the glass composition described in this disclosure were obtained under reducing melting conditions. Transmittance of a 0.71 mm thick sample was tested in the wavelength range of 200 nm to 300 nm before and after irradiation with a HOK 4 lamp. Results are shown in... Figure 3 middle.

[0218] Specifically, the results obtained for the particularly relevant wavelengths λ = 200 nm and λ = 220 nm are summarized in the table below.

[0219] Transmittance of HOK 4 before irradiation [%) Transmittance after HOK 4 irradiation [%) λ = 200nm 0.2 0.2 λ = 220nm 69.4 70.8

[0220] The glass exhibits low transmittance at 200 nm and high transmittance at 220 nm. After irradiation with a HOK4 lamp for 144 hours, the transmittance at both 200 nm and 220 nm remained essentially unchanged.

Claims

1. A method for eradicating a pathogen, the method comprising exposing the pathogen to bactericidal UV light at a wavelength of 220 nm, wherein the UV light is irradiated by a UV lamp having a lamp cover made of glass having a transmittance of at least 30% at a wavelength of 220 nm and less than 4% at a wavelength of 200 nm, the glass having a total platinum content of less than 3.5 ppm, wherein the sum of all contaminants of Pt, TiO2 and / or Fe2O3 is less than 20 ppm.

2. The method of claim 1, wherein the exposed pathogen resides on a UV-sensitive material, said UV-sensitive material being sensitive to UV radiation above 222 nm.

3. The method according to claim 2, wherein the UV-sensitive material is the surface of an animal's biological tissue, wherein the animal is selected from insects, invertebrates, vertebrates, and mammals.

4. The method of claim 3, wherein the biological tissue surface includes the eye or skin.

5. The method of claim 3, wherein the animal includes a human.

6. The method according to claim 1 or 2, wherein, according to BS ISO 22196:2011-08-31, the eradication rate of pathogens after treatment is > 99%.

7. The method according to claim 1 or 2, wherein the UV exposure of the pathogen is at least 2000 to 8000 microwatts per square centimeter (μW·s / cm²). 2 Within the range of ).

8. The method according to claim 1 or 2, wherein all or part of the cover of the UV lamp is formed in the form of a lens.

9. A glass having a transmittance of at least 30% at a wavelength of 220 nm and a transmittance of less than 4.0% at a wavelength of 200 nm, said glass having a total platinum content of less than 3.5 ppm, wherein the sum of all contaminants of Pt, TiO2 and / or Fe2O3 is less than 20 ppm.

10. The glass according to claim 9, wherein the transmittance is at least 30% at 220 nm and / or at least 75% at wavelengths [λ] of 260 nm, 280 nm and / or 310 nm.

11. The glass according to claim 9, wherein the transmittance is at least 35% at 220 nm and / or at least 75% at wavelengths [λ] of 260 nm, 280 nm and / or 310 nm.

12. The glass according to claim 9, wherein the transmittance is at least 40% at 220 nm and / or at least 75% at wavelengths [λ] of 260 nm, 280 nm and / or 310 nm.

13. The glass according to claim 9, wherein the transmittance is at least 60% at 220 nm and / or at least 75% at wavelengths [λ] of 260 nm, 280 nm and / or 310 nm.

14. The glass according to any one of claims 9 to 13, wherein the total Fe2O3 content is 0.5 to 10 ppm.

15. The glass according to claim 14, wherein the Fe2O3 content is 1 ppm to 10 ppm, the TiO2 content is 2 ppm to 10 ppm, and the transmittance at 200 nm is less than 3%.

16. The glass according to claim 14, wherein the total content of Fe2O3 is 1 to 10 ppm.

17. The glass according to any one of claims 9 to 13, wherein the total platinum content is less than 1.0 ppm.

18. The glass according to any one of claims 9 to 13, wherein the wavefront deviation (peak to valley) is less than ± 0.1 mm.

19. The glass according to any one of claims 9 to 13, wherein the refractive index n of the glass is... d The range is 1.450 to 1.

580.

20. The glass according to any one of claims 9 to 13, wherein the glass comprises the following components in mol% terms: 。 21. A glass article made of glass according to any one of claims 9 to 20, wherein the article is heat-tempered or chemically tempered and has a compressive stress of at least 50 MPa on at least one surface.

22. Use of the glass according to any one of claims 9 to 20, for use as an hermetically sealed lens cap for a UV-LED module.

23. Use of the glass according to any one of claims 9 to 20, for applications selected from the group consisting of: water disinfection, analytical instruments, air purification, air disinfection, surface disinfection, cell counting, molecular identification, protein analysis, biofilm treatment, curing, photolithography, vegetable growth, skin treatment, pathogen detection, drug discovery, protein analysis, induction and / or sterilization of skin vitamin D3 production.

24. Use of the glass according to claim 23, wherein the analytical instrument includes HPLC, a spectrometer, and a water monitoring sensor.

25. The use of glass according to claim 23, wherein the surface disinfection includes keyboard disinfection and escalator handrail ultraviolet sterilizer.

26. The use of the glass according to claim 23, wherein the skin treatment includes the treatment of psoriasis, vitiligo, pruritus, neurodermatitis, acne, actinic dermatitis, phototherapy, and pityriasis rosea.

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