Multilayer articles, systems, devices, and methods for disinfection, including an absorbent layer and an ultraviolet mirror.

Abstract

A multilayer article is provided that includes an absorbent layer and an ultraviolet mirror that includes at least a plurality of alternating first and second optical layers. The absorbent layer absorbs ultraviolet light having a wavelength of at least 230 nanometers (nm) to 400 nm. The ultraviolet mirror reflects ultraviolet light in the wavelength range of 190 nm to 240 nm. A system is also provided that includes a broadband UVC light source and a multilayer article. A device is provided that includes a chamber, a broadband UVC light source located within the chamber, an absorbent layer within the chamber, and an ultraviolet mirror between the light source and the absorbent layer. A method of disinfecting a material is also provided that includes obtaining the system or device, directing UVC light toward the ultraviolet mirror, and exposing the material to ultraviolet light in the wavelength range of 190 nm to 240 nm that is reflected by the ultraviolet mirror toward the material.

Description

[Technical Field]

[0001] This disclosure generally relates to the use of selected wavelengths of ultraviolet (UV) light. [Background technology]

[0002] Ultraviolet (UV) light is useful for initiating free radical chemical reactions in coatings, adhesives, and polymer materials, for example. UV light is also useful for disinfecting surfaces, filters, bandages, membranes, articles, air, and liquids (e.g., water). Examples of applications for UVC (i.e., ultraviolet C includes wavelengths in the range of 100 to 280 nanometers) disinfection include medical offices and medical supplies, airplane toilets, hospital rooms and surgical equipment, schools, air and water purification, and consumer applications (e.g., disinfection of toothbrushes and mobile phones). Preventing infection and disease spread, especially in high-risk environments and populations, is becoming increasingly important as pathogens mutate and develop antibiotic resistance. The rapid global movement of people increases the risk of rapidly progressing regional / global pandemics of infectious diseases. Disinfection of air and water is of paramount importance for human health and infection prevention. Advantages of UVC disinfection include contactless application and the fact that mechanical destruction of cells at gene-nonspecific targets is less likely to be overcome by mutations and the development of resistance by pathogens. Surfaces to be disinfected with ultraviolet light other than metal, ceramic, or glass surfaces need to be protected from ultraviolet light. UVC irradiation can effectively inactivate or kill prokaryotic and eukaryotic microorganisms, including bacteria, viruses, fungi, and molds. Bacterial strains that have developed resistance to one or more antibiotics are also susceptible to UVC light. Examples of pathogens of increasing concern include hospital-acquired infections (e.g., C. diff, E. coli, MRSA, Klebsiella, influenza, mycobacteria, and enterobacteria), waterborne and soilborne infections (e.g., Giardia, Legionella, Campylobacter), and airborne infections (e.g., influenza, pneumonia, tuberculosis).

[0003] However, UV light can be harmful to humans and animals to varying degrees. For example, UV light sources emitting wavelengths between 400nm and 500nm can cause long-term eye damage. [Overview of the project]

[0004] In a first embodiment, a multilayer article is provided. The multilayer article includes an absorbing layer that absorbs at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light having a wavelength of at least 230 nanometers to 400 nanometers. The absorbing layer has a main surface. The multilayer article further includes an ultraviolet mirror adjacent to the main surface of the absorbing layer. The ultraviolet mirror comprises at least a plurality of alternating first and second optical layers that collectively reflect at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of 190 nanometers, 195 nm, or 200 nm to 230 nanometers, 235 nm, or 240 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, and collectively transmit at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of over 230 nanometers, over 235 nm, or over 240 nm to 400 nanometers at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°.

[0005] In a second embodiment, a system is provided, which includes a broadband UVC light source and a multilayer article according to the first embodiment.

[0006] In a third embodiment, a device is provided. The device includes a chamber having at least one wall, a broadband UVC light source located within the chamber, an absorption layer adjacent to at least one wall of the chamber, and an ultraviolet mirror located within the chamber between the broadband UVC light source and the absorption layer. The ultraviolet mirror is composed of at least a plurality of alternating first and second optical layers that collectively reflect at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of 190 nanometers to 230 nanometers at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, and collectively transmit at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of over 230 nanometers to 400 nanometers at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°. At least 50, 60, 70, 80, 90, or 95 percent of the ultraviolet light with wavelengths of at least 230 nanometers to 400 nanometers that passes through the ultraviolet mirror is absorbed within the chamber.

[0007] A fourth aspect provides a method for disinfecting at least one material. The method includes obtaining a system according to the second aspect or a device according to the third aspect, directing UVC light from a broadband UVC light source to an ultraviolet mirror, and exposing at least one material to ultraviolet light in the wavelength range of 190 nanometers to 230 nanometers. The ultraviolet light is reflected by the ultraviolet mirror toward at least one material. The method is useful for disinfecting materials such as medical instruments, sanitary articles, air, liquids (e.g., water or beverages), filter media, food preparation equipment, and porous membranes. [Brief explanation of the drawing]

[0008] [Figure 1A] These are schematic cross-sectional views of two exemplary multilayer articles that can be prepared by this disclosure. [Figure 1B] These are schematic cross-sectional views of two exemplary multilayer articles that can be prepared by this disclosure.

[0009] [Figure 2] It is a schematic cross-sectional view of an exemplary system that can be prepared according to the present disclosure.

[0010] [Figure 3] It is a schematic cross-sectional view of an exemplary device that can be prepared according to the present disclosure.

[0011] [Figure 4] It is a flowchart of an exemplary method according to the present disclosure.

[0012] [Figure 5] It is a graph of the reflection spectrum of the ultraviolet mirror fabricated in Example 1.

[0013] [Figure 6] It is a schematic cross-sectional view of an exemplary system fabricated according to the present disclosure.

Modes for Carrying Out the Invention

[0014] Term Explanation

[0015] As used herein, "fluoropolymer" refers to any organic polymer containing fluorine.

[0016] As used herein, "incident" with respect to light refers to light shining on or hitting a material.

[0017] As used herein, the term or prefix "micro" refers to at least one dimension defining a structure or shape in the range of from 1 micrometer to 1 millimeter. For example, a micro-structure may have a height or width in the range of from 1 micrometer to 1 millimeter.

[0018] As used herein, the term or prefix "nano" refers to at least one dimension defining a structure or shape less than 1 micrometer. For example, a nanostructure may have at least one of a height or width that is less than 1 micrometer.

[0019] As used herein, "radiation" refers to electromagnetic radiation unless otherwise specified.

[0020] As used herein, "absorption" refers to the process by which a material converts the energy of light radiation into internal energy.

[0021] As used herein, "absorb" with respect to the wavelength of light encompasses both absorption and scattering, since scattered light is ultimately absorbed as well.

[0022] As used herein, "scattering" with respect to the wavelength of light refers to causing light to deviate from a straight path and travel in different directions with different intensities.

[0023] As used herein, “reflectance” is a measure of the proportion of light or other radiation reflected from a surface upon perpendicular incidence. Reflectance typically varies with wavelength and is reported as the percentage of incident light reflected from the surface (0 percent = no reflected light, 100 = all light reflected). Reflectance and reflectance are used interchangeably herein.

[0024] As used herein, "reflectivity" and "reflectivity" refer to the property of reflecting light or radiation, in particular reflectance measured independently of the thickness of the material.

[0025] As used herein, "average reflectance" refers to reflectance averaged over a specific wavelength range.

[0026] Absorbance can be measured using the method described in ASTM E903-12, "Standard Test Method for Solar Absorptance, Reflectance, and Transmittance of Materials Using Integrating Spheres." The absorbance measurements described herein were performed by first measuring the transmittance as described above, and then calculating the absorbance using Equation 1.

[0027] As used herein, the term “absorbance” in relation to quantitative measurement refers to the base-10 logarithm of the ratio of incident radiant flux to radiant flux transmitted through a material. The ratio can be described as the value obtained by dividing the radiant flux received by the material by the radiant flux transmitted through the material. Absorbance (A) can be calculated based on the transmittance (T) according to Equation 1. A = -log 10 T (1)

[0028] Emissivity can be measured using an infrared imaging radiometer by the method described in ASTM E1933-14 (2018) "Standard Practice for Measuring and Compensating for Emissibility Using Infrared Imaging Radiometers". multilayer article

[0029] In the first embodiment, a multilayer article is provided. The multilayer article is,

[0030] a) An absorbing layer having a main surface that absorbs at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light having a wavelength of at least 230 nanometers to 400 nanometers,

[0031] b) A UV mirror adjacent to the main surface of the absorption layer, comprising at least a plurality of alternating first and second optical layers, which collectively reflects at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of 190 nanometers to 240 nanometers at at least one incident light angle among 0°, 15°, 30°, 45°, 60°, or 75°, and collectively transmits at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of over 240 nanometers to 400 nanometers at at least one incident light angle among 0°, 15°, 30°, 45°, 60°, or 75°.

[0032] Alternatively, it may be desirable for the UV mirror to reflect UV light with a wavelength range somewhat different from 190nm to 240nm, and consequently transmit UV light with a different wavelength range than 240nm to 400nm. For example, in some embodiments, the UV mirror reflects UV light in a wavelength range of 190nm or 200nm to 230nm, 235nm, or 240nm, such as 190nm to 230nm, 200nm to 240nm, or 200nm to 230nm. In such embodiments, the UV mirror transmits UV light with wavelengths longer than the upper limit of the reflected wavelength range, i.e., UV light with wavelengths longer than 230nm, 235nm, or 240nm. It should be understood that for each of these wavelengths / wavelength ranges, the ultraviolet mirror is exposed to at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, and the optical layer collectively reflects at least 50, 60, 70, 80, 90, or 95 percent of the incident ultraviolet light in a particular wavelength range, and collectively transmits at least 50, 60, 70, 80, 90, or 95 percent of the incident ultraviolet light in a particular wavelength range at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°.

[0033] It should be understood that the percentage of incident light absorbed refers to the amount of absorption integrated over a specific wavelength range (as opposed to the amount of absorption at a single wavelength).

[0034] Advantageously, the combination of an absorbing layer and an ultraviolet mirror in a multilayer article enables the use of a broadband UV light source, ultimately providing UVC light in a relatively narrow bandwidth (e.g., in the range of 190 nanometers to 240 nanometers). This is achieved by 1) the ultraviolet mirror i) reflecting light having wavelengths in the range of approximately 190 nm to 240 nm, and ii) transmitting light having wavelengths from longer than the maximum wavelength of the reflection range to 400 nm, and 2) the absorbing layer absorbing light having wavelengths in the range of 230 nm to 400 nm. As described above, typically, absorption, transmission, and / or reflection are less than 100% of the total incident light. In the most preferred embodiment, more than 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, or 98% or more of the incident light are absorbed, transmitted, and / or reflected. Light wavelengths below 230 nm have not been found to be carcinogenic to human skin; therefore, reflection of 190 nm to 230 nm by UV mirrors can assist in disinfection with less risk to nearby people. Light wavelengths of 240 nm to 230 nm may also be acceptable in some applications. In some embodiments, multilayer articles have UV reflectivity of more than 90% (more than 99% in some embodiments) specifically at a wavelength of at least 222 nm.

[0035] The absorption layer preferably resists UV-induced damage / degradation over time by absorbing UV light that can pass through the UV mirror. UV light, especially UV light with wavelengths in the range of 280 nm to 400 nm, can cause degradation of plastics, leading to discoloration and deterioration of optical and mechanical properties. Suppression of photo-oxidative degradation is important, for example, for outdoor applications where long-term durability is essential. UV light absorption by polyethylene terephthalate begins, for example, at about 360 nm, increases significantly below 320 nm, and is very pronounced below 300 nm. Polyethylene naphthalate strongly absorbs UV light in the range of 310 nm to 370 nm, with an absorption tail extending to about 410 nm, and absorption maxima occurring at 352 nm and 337 nm. Chain cleavage occurs in the presence of oxygen, and the main photo-oxidation products are carbon monoxide, carbon dioxide, and carboxylic acid. In addition to the direct photodegradation of ester groups, oxidation reactions must be considered, which also form carbon dioxide via peroxide radicals.

[0036] Generally, the absorption layer may contain any polymer composition (i.e., polymer + additives) that can withstand ultraviolet light for extended periods while absorbing (including scattering) ultraviolet light. In some embodiments, the absorption layer includes silicone thermoplastic resins, fluoropolymers, copolymers thereof, or blends thereof. In some embodiments, the absorption layer includes fluoropolymers (co)polymers comprising polymerization units derived from one or more monomers selected from tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, perfluoroalkoxyalkanes, or combinations thereof. In the context of this specification, the term “polymer” is understood to include homopolymers and copolymers, as well as polymers or copolymers that can be formed in miscible blends, for example by co-extrusion or by reactions including transesterification. The terms “polymer” and “copolymer” also include both random copolymers and block copolymers. These polymers suitable for absorption layers tend to degrade less upon exposure to ultraviolet light (e.g., wavelengths of 190 nm to 400 nm) than other polymers formed from different monomers.

[0037] In some embodiments, the absorption layer comprises one or more of the following: UV absorbers, UV scatterers, hindered amine light stabilizers, antioxidants, pigments, or combinations thereof. Suitable UV absorbers include carbon black, titanium dioxide, zinc oxide, cesium dioxide, zirconium dioxide, or combinations thereof. These particular UV absorbers tend to be stable to UV light in addition to absorbing it. Further suitable UV absorbers include benzotriazole compounds, benzophenone compounds, and triazine compounds (including, for example, any combination thereof).

[0038] Some suitable UV absorbers are redshift UV absorbers (RUVAs) that absorb at least 70% (in some embodiments, at least 80%, or even more than 90%) of UV light in the wavelength range of 180 nm to 400 nm. Typically, it is desirable that the RUVA is highly soluble in the polymer of the absorption layer, highly light-absorbing, photostillable, and thermally stable in the 200°C to 300°C temperature range of the extrusion process for forming the protect.

[0039] RUVA typically has an enhanced spectral effective range in the long-wave UV region and can block long-wavelength UV light that can cause yellowing of polyesters. Typical UV protective layers have a thickness ranging from 13 micrometers to 380 micrometers (0.5 mil to 15 mil) and a RUVA concentration of 2 to 10% by weight. One of the most effective RUVAs is the benzotriazole compound, 5-trifluoromethyl-2-(2-hydroxy-3-α-cumyl-5-tert-octylphenyl)-2H-benzotriazole (available from BASF (Florham Park, NJ) under the trade name "CGL-0139"). Other exemplary benzotriazoles include 2-(2-hydroxy-3,5-di-α-cumylphenyl)-2H-benzotriazole, 5-chloro-2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-2H-benzothiazole, 5-chloro-2-(2-hydroxy-3,5-di-tert-butylphenyl)-2H-benzotriazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)-2H-benzotriazole, 2-(2-hydroxy-3-α-cumyl-5-tert-octylphenyl)-2H-benzotriazole, and 2-(3-tert-butyl-2-hydroxy-5-methylphenyl)-5-chloro-2H-benzotriazole. A further exemplary RUVA is 2(-4,6-diphenyl-1-3,5-triazine-2-yl)-5-hexyloxyphenol. Other exemplary UV absorbers are available from BASF under trade names "TINUVIN 1577," "TINUVIN 900," "TINUVIN 1600," and "TINUVIN 777." Other exemplary UV absorbers are available, for example, from Sukano Polymers Corporation (Dunkin, SC) under the trade name "TA07-07 MB" in the form of a polyester masterbatch. An exemplary UV absorber for polymethyl methacrylate is a masterbatch available, for example, from Sukano Polymers Corporation under the trade name "TA11-10 MBO1."An exemplary UV absorber for polycarbonate is the masterbatch "TA28-09 MB01" from Sukano Polymers Corporation. Furthermore, the UV absorber can be used in combination with hindered amine light stabilizers (HALS) and antioxidants. Exemplary HALS are available from BASF under the trade names "CHIMASSORB 944" and "TINUVIN 123". Exemplary antioxidants are also available from BASF under the trade names "IRGANOX 1010" and "ULTRANOX 626".

[0040] In selected embodiments, the absorbing layer further absorbs at least 30 percent, 40, 50, 60, 70, 80, or at least 90 percent of incident visible light having wavelengths of at least 400 nm to 700 nm. Typically, multilayer articles do not need to be transparent to visible light, and therefore, it may be preferable that the absorbing layer absorbs 70 percent or more of incident visible light having wavelengths of at least 400 nm to 700 nm to minimize the reflection of visible light returning from the multilayer article.

[0041] In a selected embodiment, the absorbing layer reflects at least 30 percent, at least 40 percent, at least 50 percent, at least 60 percent, at least 70 percent, at least 80 percent, or at least 90 percent of incident visible light having wavelengths of at least 400 nanometers to 700 nanometers.

[0042] An ultraviolet mirror comprises multiple pairs of low / high refractive index film layers, each pair of low / high refractive index layers having a total optical thickness that is half the central wavelength of the band it is designed to reflect. Such a laminate of films is generally called a quarter-wavelength laminate. In some embodiments, different pairs of low / high refractive index layers may have different total optical thicknesses, for example, when a broadband reflective optical film is desired. The material used for the ultraviolet mirror is preferably resistant to ultraviolet light. Many fluoropolymers and certain inorganic materials are resistant to ultraviolet light.

[0043] In some embodiments of the ultraviolet mirrors described herein, at least a first optical layer comprises an inorganic material (e.g., at least one of zirconium oxynitride, hafnia, alumina, magnesium oxide, yttrium oxide, lanthanum fluoride, or neodymium fluoride), and a second optical layer comprises an inorganic material (e.g., at least one of silica, aluminum fluoride, magnesium fluoride, calcium fluoride, silica-alumina oxide, or alumina-doped silica). Exemplary materials are available, for example, from Materion Corporation (Mayfield Heights, OH) and Umicore Corporation (Brussels, Belgium).

[0044] In some embodiments of the ultraviolet mirrors described herein, at least a first optical layer comprises a polymer material (e.g., at least one of polyvinylidene fluoride (PVDF) and ethylene tetrafluoroethylene (ETFE)), and a second optical layer comprises a polymer material (e.g., at least one of copolymers (THV), or polyethylene copolymers containing subunits derived from tetrafluoroethylene (TFE), hexafluoropropylene (HFP), and vinylidene fluoride (VDF), copolymers (FEP) containing subunits derived from tetrafluoroethylene (TFE) and hexafluoropropylene (HFP), or perfluoroalkoxyalkanes (PFA)).

[0045] The second optical layer may include fluorinated copolymer materials such as fluorinated ethylene propylene copolymer (FEP); copolymers of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride (THV); and at least one copolymer of tetrafluoroethylene, hexafluoropropylene, or ethylene. Particularly useful are melt-processable copolymers of tetrafluoroethylene and at least two or even at least three additional separate comonomers.

[0046] In some embodiments, the first optical layer is a fluoropolymer, and the second optical layer is a fluoropolymer. Examples of materials preferred in such embodiments include ETFE / THV, PMMA / THV, PVDF / FEP, ETFE / FEP, PVDF / PFA, and ETFE / PFA. In selected embodiments, at least the first optical layer comprises at least one of polyvinylidene fluoride or ethylene tetrafluoroethylene (ETFE), and the second optical layer comprises a copolymer of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride (THV).

[0047] Examples of melt-processable copolymers consisting of the aforementioned tetrafluoroethylene and other monomers include: Dyneon LLC (Oakdale, MN) trade names "Dyneon THV 220", "Dyneon THV 230", "Dyneon THV 2030", "Dyneon THV 500", "Dyneon THV 610", and "Dyneon THV 815", available as copolymers of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride; "NEOFLON EFEP" from Daikin Industries, Ltd. (Osaka, Japan); "AFLAS" from Asahi Glass Co., Ltd. (Tokyo, Japan); copolymers of ethylene and tetrafluoroethylene available under the trade names "DYNEON ET 6210A" and "DYNEON ET 6235" from Dyneon LLC; and EIduPont de Nemours and Examples include "TEFZEL ETFE" manufactured by Co. (Wilmington, DE) and "Fluon ETFE" manufactured by Asahi Glass Co., Ltd.

[0048] The ultraviolet mirrors described herein include, for example, U.S. Patent Nos. 5,882,774 (Jonza et al.), 6,045,894 (Jonza et al.), 6,368,699 (Gilbert et al.), 6,531,230 (Weber et al.), 6,667,095 (Wheatley et al.), 6,783,349 (Neavin et al.), 7,271,951 (B2) (Weber et al.), and 7,632 As described in publications 568 (Padiyath et al.), 7,652,736 (Padiyath et al.), and 7,952,805 (McGurran et al.), as well as in international publications 95 / 17303 (Ouderkirk et al.) and 99 / 39224 (Ouderkirk et al.), these can be manufactured using common processing techniques, such as by co-extrusion of alternating polymer layers having different refractive indices.

[0049] Desirable techniques for providing a spectrally controlled ultraviolet mirror include, for example, the use of an axial rod heater to control the thickness of a co-extruded polymer layer, as described in U.S. Patent No. 6,783,349 (Neavin et al.), timely feedback of the thickness profile during manufacturing from a thickness measuring tool (e.g., atomic force microscope (AFM), transmission electron microscope, or scanning electron microscope), optical modeling to obtain a desired thickness profile, and repeated adjustment of the axial rod based on the difference between the measured thickness profile and the desired thickness profile.

[0050] The basic process of controlling layer thickness profiles involves adjusting the axial rod zone power settings based on the difference between the target layer thickness profile and the measured layer profile. The increase in axial rod force required to adjust the layer thickness value in a given feedblock zone may first be calibrated against the heat input watts per nanometer of the resulting thickness change in the layer within that heater zone. For example, fine spectral control is possible using 24 axial rod zones for 275 layers. Once calibrated, given the target and measured profiles, the required power adjustments can be calculated. This procedure is repeated until the two profiles converge.

[0051] The layer thickness profile (thickness value) of the ultraviolet mirror described herein, which reflects at least 50 percent of incident UV light over a specific wavelength range, can be adjusted to be a nearly linear profile, with the first (thinnest) optical layer adjusted to have an optical thickness (refractive index × physical thickness) of about 1 / 4 wavelength for 190 nm light, and the thickest layer adjusted to have an optical thickness of about 1 / 4 wavelength for 240 nm light or 230 nm light.

[0052] Dielectric mirrors, which have an optical thin-film laminate design composed of alternating thin layers of inorganic dielectric material with refractive index contrast, are particularly well suited to this purpose. In recent decades, dielectric mirrors have been used in applications in the UV, visible, NIR, and IR spectral regions. Depending on the spectral region being targeted, there are specific materials suitable for that region. Also, one of two forms of physical vapor deposition (PVD), namely evaporation or sputtering, is used to coat these materials. Evaporation of a coating is done by heating the coating material (deposited material) to a temperature at which it evaporates. This is followed by condensing the vapor onto the substrate. For evaporation dielectric mirror coatings, the electron beam evaporation process is most commonly used. Sputtering coating uses energy gas ions to collide with the surface of the material ("target"), causing atoms to fly out, which then condense onto the nearby substrate. The thin-film coating rate and structure-property relationship are strongly influenced by the coating method used and the settings used for that method. Ideally, the coating rate should be high enough to enable acceptable process throughput and film performance, characterized by a high-density, low-stress, void-free, and non-optically absorbing coating layer.

[0053] An exemplary embodiment can be designed to have a peak reflectance at 222 nm by both PVD methods. For example, separate substrates are coated by electron beam deposition using HfO2 as the high refractive index material and SiO2 as the low refractive index material. In the mirror design, there are alternating layers of "quarter-wavelength optical thickness" (qwot) of each material, and these layers are coated layer by layer, for example, until the reflectance at 215 nm exceeds 95% after 11 layers. The bandwidth of this reflectance peak is approximately 50 nm. The quarter-wavelength optical thickness is the design wavelength (215 nm in this case) divided by 4, i.e., 53.75 nm. The physical thickness of the high refractive index layer (HfO2) is the quotient of the qwot of HfO2 and the refractive index (2.35) at 215 nm, or 23.2 nm. The physical thickness of the low refractive index layer (MgF2) with a refractive index of 1.42 at 215 nm is 37.85 nm. Next, the coating of a thin-film laminate, composed of alternating layers of HfO2 and SiO2 and designed to have a peak reflectivity at 215 nm, is initiated by coating layer 1 with HfO2 at 23.2 nm. For electron beam deposition, four hearths are used as deposition sources. Each hearth is conical in shape and has a volume of 17 cm³. 3A mass of HfO2 is filled into the substrate. A magnetically deflected high-voltage electron beam is raster-scanned across the material surface while gradually increasing the beam's filament current in a pre-programmed manner. Once the pre-programmed process is complete, the HFO2 surface is heated to approximately 2500°C, the deposition temperature, the source shutter opens, and the HfO2 vapor flux exits the source in a cosine distribution and condenses on the substrate material above the source. To improve the uniformity of the coating, the substrate holder rotates during deposition. Once a predetermined coating thickness (23.2 nm) is reached, the filament current is cut off, the shutter closes, and the HfO2 material is cooled. For layer 2, the deposition source is then rotated to a hearth containing a mass of MgF2, and a similar pre-programmed heating process is initiated. Here, the MgF2 surface temperature is approximately 950°C when the supply shutter is open. Once a predetermined coating thickness (37.85 nm) is reached, the filament current is cut off, the shutter closes, and the HfO2 material is cooled. This stepwise process continues layer by layer until the total number of design layers is reached. In this optical design, as the total number of layers increases from 3 to 11, the resulting peak reflectivity increases accordingly from 40% at 3 layers to over 95% at 11 layers.

[0054] Optionally, ultraviolet mirrors can be fabricated using a continuous roll-to-roll (R2R) method with ZrON as the high refractive index material and SiO2 as the low refractive index material. The optical design is the same type as that of a thin-film laminate, with alternating layers of the two materials. For ZrON with a refractive index of 3.1 at 215 nm, the target physical thickness was 17.3 nm. Here, for SiO2 with a refractive index of 1.61, sputtered from an aluminum-doped silicon sputtering target, the target thickness was 33.3 nm. Layer 1 of ZrON is DC sputtered from a pure zirconium sputtering target in a gas mixture of argon, oxygen, and nitrogen. Argon is the primary sputtering gas, while the levels of oxygen and nitrogen are set to achieve transparency, low absorptivity, and high refractive index. The transport of the film roll starts at a predetermined speed, the output of the sputtering source is increased to the maximum operating output, and then a steady state is reached after the reactive gas is introduced. Depending on the length of the film to be coated, this process continues until the entire length is reached. Here, the sputtering source is perpendicular to and wider than the film being coated, resulting in very high uniformity of coating thickness. When the coated film reaches the desired length, the reactive gas is set to zero and the target is sputtered to a pure Zr surface state. Next, the film direction is reversed and AC frequency (40 kHz) power is applied to the pair of rotary silicon (aluminum-doped) sputtering targets in an argon sputtering atmosphere. Once a steady state is reached, oxygen reactive gas is introduced to provide transparency and a low refractive index. The second layer is coated over the length coated by layer 1 at a predetermined process setting and line speed. Again, these sputtering sources are perpendicular to and wider than the film being coated, resulting in very high uniformity of coating thickness. After the coated film reaches the desired length, the reactive oxygen is removed and the target is sputtered in argon to a pure silicon (aluminum-doped) surface state. Depending on the peak reflectivity target, layers 3-5, or 7, or 9, or 11, or 13 are coated in this order.After completion, remove the film roll for post-processing.

[0055] For the manufacture of these inorganic coatings, electron beam processes are most suitable for coating individual components. While R2R film coating has been successfully implemented in some chambers, a layer-by-layer coating sequence is still necessary. For R2R sputtering of films, it is advantageous to use a sputtering system with multiple sources arranged around one or possibly two coating drums. Here, for a 13-layer optical laminate design, two or even a single machine pass process is feasible, sequentially coating high-refractive-index and low-refractive-index layers alternately. The number of machine passes required will depend on the machine design, cost, and the practicality of 13 consecutive sources. Additionally, the coating speed must match the speed of a single film line.

[0056] Preferably, the ultraviolet mirror reflects at least 80 percent, 85, 90, 91, 92, 93, 94, 95, 96, 97, or at least 98 percent of incident ultraviolet light in the wavelength range of 200 nanometers to 230 nanometers at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°. The choice of material combination used to fabricate the ultraviolet mirror depends, for example, on the desired bandwidth to be reflected. The greater the refractive index difference between the first optical layer polymer and the second optical layer polymer, the greater the optical power produced, thereby increasing the reflection bandwidth for each pair of layers. The number of optical layers is selected to achieve the desired optical properties using the minimum number of layers for reasons of film thickness, flexibility, and economics. In the case of reflective films such as mirrors, the number of layers is preferably less than about 2,000, more preferably less than about 1,000, and even more preferably less than about 750. In some embodiments, the number of layers is at least 100, 125, 150, 175, or at least 200. However, because zirconia has a very high refractive index, when using zirconia or zirconia oxynitride, the number of optical layers required can be much smaller, and may be 50 or fewer optical layers, 40, 30, 20, or 15 or fewer optical layers, and 3 or more optical layers, or 5, 7, or 10 or more optical layers.

[0057] In some embodiments, the ultraviolet mirror has a reflection spectrum at an incident angle of 0° (e.g., perpendicular incidence) that shifts to shorter wavelengths at oblique angles (e.g., 15°, 30°, 45°, 60°, or 75°). Thus, an ultraviolet mirror with a perpendicular incidence spectrum can be fabricated such that, at the intended incident angle, the ultraviolet mirror reflects ultraviolet light in the range of 190 nm to 240 nm. Optionally, an optical element (e.g., a prism, louver, etc.) is placed between the ultraviolet mirror and the UVC light source to change or limit the incident angle of the light emitted by the UVC light source before it reaches the outer surface of the ultraviolet mirror. Furthermore, the shape of the outer surface of the ultraviolet mirror can be formed so that the incident angle is maintained for various positions on the ultraviolet mirror.

[0058] In some embodiments, the ultraviolet mirror absorbs at least 30 percent, 40, 50, 60, 70, 80, 90 percent, at least 95 percent, or at least 98 percent of incident visible light having wavelengths of at least 400 nm to 700 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°. Optionally, pigments or dyes can be included in the ultraviolet mirror to absorb one or more wavelengths between 400 nm and 700 nm. Suitable pigments include, for example, metal oxides such as antimony tin oxide, indium tin oxide, cesium oxide, iron oxide, and cuprous oxide. As described above with respect to the absorption layer, typically, the multilayer article does not need to be transparent to visible light, and therefore, it may be preferable that the ultraviolet mirror absorbs at least 30 percent of incident visible light having wavelengths of at least 400 nm to 700 nm to minimize the reflection of visible light returning from the multilayer article.

[0059] Referring to Figures 1A and 1B, schematic cross-sectional views of two exemplary multilayer articles 10, each including an ultraviolet mirror 5, are presented, the ultraviolet mirror comprising a first optical layer 12A, 12B, 12N, a second optical layer 13A, 13B, 13N, and an absorbing layer 14 adjacent to the ultraviolet mirror.

[0060] In some embodiments, the main surface of the absorption layer 14 is in direct contact with the main surface of the ultraviolet mirror 5. In other embodiments, the multilayer article 10 has a gap 11 between the absorption layer 14 and the ultraviolet mirror 5, as shown in the figure. For example, the gap can be created by taping the edge of the absorption layer to the ultraviolet mirror. By attaching the two layers using adhesive tape, it is also possible to use an ultraviolet mirror with a shape different from that of the absorption layer.

[0061] Referring to Figure 1A, the multilayer article 10 optionally further comprises an adhesive layer 15 adjacent to the absorbent layer 14, the absorbent layer 14 being positioned between the UV mirror 5 and the adhesive layer 15. The adhesive may be useful for attaching the multilayer article to a substrate (e.g., a wall, ceiling, device housing, etc.). Such an optional adhesive layer may contain any adhesive (e.g., a thermosetting adhesive, a hot melt adhesive, and / or a pressure-sensitive adhesive). If present, the optional adhesive layer preferably contains a pressure-sensitive adhesive. In some embodiments, the adhesive may be resistant to UV damage. Exemplary adhesives that are typically resistant to UV damage include, for example, silicone and acrylic adhesives containing UV stabilizing / blocking additives, as described above. The optional adhesive layer may contain thermally conductive particles to aid in heat transfer. Examples of thermally conductive particles include aluminum oxide particles, alumina nanoparticles, aluminum trihydrate, aluminum-coated glass beads, metal silicides, graphite, graphene, carbon nanotubes, hexagonal boron nitride particles and aggregates (e.g., available from 3M Company as 3M BORON DINITRIDE), graphene particles, graphene oxide particles, metal particles, and combinations thereof. Furthermore, optional release liners used with optional adhesive layers may include, for example, polyolefin films, fluoropolymer films, coated PET films, or silicone-treated films or paper.

[0062] Referring to Figure 1B, the multilayer article optionally further comprises one or more of the following: a heat transfer layer 16, a plurality of heat transfer fins 17, or a plurality of heat transfer pins 17, adjacent to the main surface 4 of the absorption layer 14 and on the side opposite to the ultraviolet mirror 5. Suitable materials that may constitute the heat transfer layer, fins, and / or pins include metals such as aluminum, silver, gold, copper, nickel, iron, steel, or titanium. The heat transfer layer, the plurality of heat transfer fins, and the plurality of heat transfer pins may include polymers filled with thermally conductive particles, including aluminum oxide particles, alumina nanoparticles, aluminum trihydrate, aluminum-coated glass beads, metal silicides, graphite, graphene, carbon nanotubes, hexagonal boron nitride particles and aggregates (e.g., available from 3M Company as 3M BORON DINITRIDE), graphene particles, graphene oxide particles, metal particles, and combinations thereof.

[0063] Referring again to Figures 1A and 1B, additional optional features are presented. For example, in some embodiments, the (e.g., outer) main surface of the ultraviolet mirror 5 may have a plurality of non-planar features 19 protruding from the main surface. Non-planar features of any shape (e.g., prism, ridge, linear and / or curved polygon) may be preferred. In the illustrated embodiment, the non-planar features 19 have the shape of a triangular prism. Such non-planar features may be microstructured and / or nanostructured over part or all of their surface, for example, as described in PCT International Application Publication WO2019 / 130198 (Hebrink et al.). In some embodiments, the nanostructure may be superimposed on the microstructure on the surface of the ultraviolet mirror. The microstructure may consist of a series of alternating micropeaks and microspaces. The size and shape of the microspaces between the micropeaks may reduce the adhesion of fouling particles to the micropeaks. The nanostructure may consist of at least a series of nanopeaks arranged at least on the microspaces. Micropeaks may be more resistant to environmental effects than nanopeaks. Because micropeaks are spaced only by microspaces, and microspaces are significantly higher than nanopeaks, micropeaks can protect nanopeaks on the surface of microspaces from abrasion. Furthermore, non-planar features may act as light-diffusing structures by scattering UVC light reflected from ultraviolet mirrors.

[0064] In some embodiments, the ultraviolet mirror may have a structure to provide light diffusion in particular when the reflected light is directed towards an area where people may be present (e.g., a room). Such a light diffusion structure may be provided by including inorganic particles. For example, each structure may correspond to one inorganic particle. The inorganic particles may be dispersed in or arranged on top of at least one layer of the ultraviolet mirror. The inorganic particles may include titania, silica, zirconia, or zinc oxide. The inorganic particles may be in the form of beads or microbeads. The inorganic particles may be formed from ceramic material, glass, or various combinations thereof. In some embodiments, the inorganic particles have an effective D of at least 1 (in some embodiments, at least 3, 5, 6, 7, 8, 9, 10, or even at least 20) micrometers. 90 It has a particle size. In some embodiments, the inorganic particles have an effective D of up to 40 (in some embodiments, up to 25, 20, 15, 14, 13, 12, 11, 10, 9, or even up to 8) micrometers. 90 The particles have a particle size. The surface structure may also include cross-linked polymer beads, such as those traded as "CHEMISNOW" available from Soken Chemical & Engineering Company (Tokyo, Japan). As defined in NIST "Particle Size Characterization," ASTM B15-96 defines a section as having 90% of the sample mass containing particles with a diameter less than that value. 90 This explains the following: For example, D10 micrometers 90 This identifies that 90% of the sample mass contains particles with a diameter of less than 10 micrometers.

[0065] In some embodiments, the absorption layer 14 comprises a continuous metal coating or layer 18. Suitable coating or layer thicknesses include 50 nm or more, 55 nm, 60 nm, 65 nm, 70 nm, or 75 nm or more, and 100 nm or less, 95 nm, 90 nm, 85 nm, or 80 nm or less. In some embodiments, the continuous metal coating or layer constitutes the entire absorption layer 14, while in the embodiments shown in Figures 1A and 1B, the continuous metal coating or layer is used in combination with a polymer absorbing material. In some embodiments, the absorption layer includes metal particles arranged within a polymer matrix (not shown). The size of the metal particles is not particularly limited, and the average particle size of the metal particles may range from 10 nm to 10,000 nm (10 micrometers). Suitable metals for use as a coating, layer, or multiple particles include one or more of silver, gold, copper, nickel, or titanium. The use of metal in certain embodiments can increase the absorption of incident light (e.g., visible light) having wavelengths of at least 400 nm to 700 nm. Furthermore, metals can reduce damage to thermoplastic resins by scattering or absorbing harmful UV radiation. U.S. Patent No. 5,504,134 (Palmer et al.) describes the mitigation of UV-induced polymer substrate degradation by using metal oxide particles with a particle size of approximately 0.001 to 0.2 micrometers (in some embodiments, approximately 0.01 to 0.15 micrometers), for example. U.S. Patent No. 5,876,688 (Laundon) describes a method for producing finely powdered zinc oxide that is small enough to be transparent when incorporated as a UV-blocking and / or scattering agent in paints, coatings, finishes, plastic articles, and cosmetic materials, etc., which are well suitable for use in the present invention. These fine particles, such as zinc oxide and titanium oxide, with particle sizes in the range of 10 nm to 100 nm that can attenuate UV irradiation, are available, for example, from Kobo Products, Inc. (South Plainfield, NJ). Flame retardants may also be added to the absorbent layer as additives. system

[0066] In a second aspect, the disclosure provides a system. The system is

[0067] a) A broadband UVC light source,

[0068] b) comprising a multilayer article of the first embodiment.

[0069] Referring to Figure 2, a schematic cross-sectional view of an exemplary system 200 is presented. The system comprises a broadband UVC light source 220 and a multilayer article 210 according to any of the embodiments of the first aspect described above. As stated above, "UVC" refers to the wavelength of light in the range of 100 nm to 280 nm. A broadband UVC light source provides a wavelength band within this UVC wavelength range of 30 nm or more, in contrast to providing a smaller wavelength band (such as that which may be provided by a light-emitting diode (LED) light source).

[0070] In the embodiment shown in Figure 2, the multilayer article 210 comprises an absorption layer 214 directly attached to the ultraviolet mirror 205. Furthermore, the multilayer article 210 has a hollow, non-planar shape. Typically, in the system according to this disclosure, a broadband UVC light source 220 is configured to direct light onto the ultraviolet mirror 205 of the multilayer article 210. This allows the ultraviolet mirror 205 to transmit and / or absorb light with wavelengths longer than the maximum value of a desired range (e.g., 190 nm to 240 nm) to the absorption layer 214, while reflecting back light with wavelengths within that range. Preferably, any material that is also directly exposed to the emission of light from the broadband UVC light source is positioned at least 3 centimeters (cm), 3.25 cm, 3.5 cm, 3.75 cm, or at least 4 cm away from the broadband UVC light source to minimize exposure to light of wavelengths not reflected by the ultraviolet mirror 205.

[0071] In an exemplary embodiment of the system, the UVC collimator may comprise a UVC mirror that reflects wavelengths of 200 nm to a maximum of 240 nm (e.g., 230 nm, 235 nm, or 240 nm) and an absorbing layer that absorbs wavelengths of 230 nm to 400 nm. In one use, the system may be used in a room where people are present. In such an embodiment, the multilayer article can be mounted on the ceiling (i.e., the absorbing layer is positioned between the ceiling and the UV mirror), and the collimator is tilted upward toward the ceiling at a certain angle. For example, the collimator may be mounted on the wall of the room. Light with wavelengths of 200 nm to 230 nm (or ~235 nm or 240 nm) is then reflected from the UV mirror of the multilayer article onto the person. To more uniformly distribute the UVC light with wavelengths of 200 to 230 nm throughout the room, a light-diffusing surface structure can be provided on the UVC mirror film adjacent to the ceiling.

[0072] More specifically, the system comprises a UVC collimator, a broadband UVC light source, and a multilayer article having a UVC mirror and an absorbing layer. The multilayer article is positioned adjacent to the ceiling of the room, and the UVC collimator is configured to collimate light from the broadband UVC light source and direct the collimated light at a certain angle toward the UVC mirror of the multilayer article adjacent to the ceiling. The absorbing layer absorbs at least 50, 60, 70, 80, 90, or 95 percent of the incident ultraviolet light having wavelengths of at least 230 nanometers to 400 nanometers. The absorbing layer has a main surface, and the ultraviolet mirror is adjacent to the main surface of the absorbing layer. An ultraviolet mirror consists of at least several alternating first and second optical layers that collectively reflect at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of 200 nm to 230 nanometers, 235 nm, or 240 nm, and collectively transmit at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of over 230 nanometers, over 235 nm, or over 240 nm to 400 nanometers. An optical collimator can be designed to collimate light from a point source, which can be collimated using a parabolic (elliptic) reflective optical element. The main requirements are that the light source is located near the focal point of the optical element, and that the light source is relatively small compared to the size of the optical element. A light condenser can be designed using a plane of revolution generated from a portion of an ellipse, with the light source at one focal point of the ellipse and the target at the other focal point of the ellipse. A light source at one focal point illuminates the nearest vertex of the ellipse. The portion of the ellipse used to generate the plane of revolution is defined by the diameter through the light source and the vertex closest to the light source. The diameter must be larger than the light source so that the light concentrator can collect most of the light from the light source. If the light source and target are points, all the light from the light source will be collected on the target.

[0073] Light from a point source can be collimated (focused) using a parabolic (elliptical) reflective optical element, and one type of collimator suitable for the system is a parabolic collimator. The main requirements are that the light source is located near the focus of the optical element and that the light source is relatively small compared to the size of the optical element. For most applications, the optical element needs to be designed according to practical considerations such as the size of the light source and the allowable space in the optical element. Given a design volume consisting of the diameter Ds (1D width) of the source, as well as the height Hv and diameter Dv (1D width), it is possible to derive an equation for the shape of a nearly optimal parabolic reflector. y = a*(x + b) 2 + offset

[0074] where a = Hv / ((Dv / 2) 2 - (Ds / 2) 2 ), b = -Dv / 2, and offset = -a*(Ds / 2) 2 and

[0075] it is necessary to further select Hv and / or Dv such that the focus of the parabola coincides with the position of the light source at [x = Dv / 2, y = 0], which is achieved by selecting: Hv = ((Dv / 2) 2 - (Ds / 2) 2 ).

[0076] The resulting optical element is nearly optimal considering the physical constraints of the system. According to the conservation law of étendue, the amount of collimation is proportional to (Dv / Ds) 2 and the collimation increases as the design volume increases. The cut-off angle of this optical element is given by: Theta = + / - atan((Dv / 2 + Ds / 2) / Hv).

[0077] In another exemplary embodiment of the system, the UVC reflective chamber may comprise a UVC mirror that reflects wavelengths of 200 nm and up to 240 nm (e.g., 230 nm, 235 nm, or 240 nm) and an absorbing layer that absorbs wavelengths from 230 nm to 400 nm. In one use, the system may be used in a room where people are present. In such an embodiment, the multilayer article can be mounted on the ceiling (i.e., the absorbing layer is positioned between the ceiling and the UV mirror), and the chamber is tilted upward toward the ceiling at a certain angle. For example, the UVC reflective chamber may be mounted on the wall of the room. Light with wavelengths of 200 nm to 230 nm (or ~235 nm or 240 nm) is then reflected from the UV mirror of the multilayer article onto the person. The system comprises a UVC reflective chamber, a broadband UVC light source, and a multilayer article comprising a UVC mirror and an absorbing layer. The multilayer article is positioned adjacent to the ceiling of the room, and the UVC chamber is configured to direct light from a broadband UVC light source and to direct the UVC light at an angle toward the UVC mirror of the multilayer article adjacent to the ceiling. The absorbing layer absorbs at least 50, 60, 70, 80, 90, or 95 percent of the incident ultraviolet light having wavelengths of at least 230 nanometers to 400 nanometers. The absorbing layer has a main surface, and the ultraviolet mirror is adjacent to the main surface of the absorbing layer. The ultraviolet mirror consists of at least a plurality of alternating first and second optical layers that collectively reflect at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of 200 nm to 230 nanometers, 235 nm, or 240 nm, and collectively transmit at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of over 230 nanometers, over 235 nm, or over 240 nm to 400 nanometers. To more uniformly disperse UVC light with wavelengths of 200-230 nm throughout the room, a light-diffusing surface structure can be provided on the UVC mirror film adjacent to the ceiling.

[0078] Suitable broadband UVC light sources include low-pressure mercury lamps, medium-pressure mercury lamps, xenon arc lamps, or excimer lamps. Suitable low-pressure mercury lamps include those commercially available from Heraeus-Noblelight (Hanau, Germany), including low-pressure mercury amalgam lamps. For example, low-pressure mercury lamps can provide peak emission at approximately 254 nm and minimum emission at wavelengths below approximately 245 nm and above approximately 260 nm. Suitable medium-pressure mercury lamps include those commercially available from Helios Quartz Americas (Sylvania, OH). Using a Type 214 quartz sleeve or synthetic quartz sleeve with a medium-pressure mercury lamp can increase the emission at 200 nm by 51% or 89%, respectively. While the peak emission of a medium-pressure mercury lamp is approximately 320 nm, it is also pleochroic, exhibiting several prominent emission peaks from approximately 245 nm to 300 nm, for example, at approximately 265 nm, as well as a broad emission band from approximately 210 nm to 240 nm.

[0079] Suitable xenon arc lamps are commercially available from Atlas Material Testing Technology, Inc. (Chicago, IL), Newport (Irvine, CA), and Xenex (San Antonio, TX). Xenon arc lamps tend to have a broad emission spectrum, starting somewhere between approximately 200 nm and 250 nm, extending beyond 800 nm, and having several small peaks at approximately 475 nm and 775 nm.

[0080] Examples of excimer ultraviolet light sources include those commercially available from Sterilray (Somersworth, NH) (e.g., krypton chloride UVC lamps with an emission peak at 222 nm), Osram (Massachusetts, United States), Heraeus-Noblelight (Hanau, Germany), Ushio (Tokyo, Japan), glow discharge lamps such as those described in Kogelschatz, Applied Surface Science, 54 (1992), 410-423, and European Patent Application Nos. 521 and 553 (granted to NVPhilips), deuterium lamps available from Hamamatsu (Hamamatsu City, Japan), and those described in Kitamura et al., Applied Surface Science, 79 / 80 (1994), 507-513 and (Fusion). Examples of lamps include microwave-driven lamps, such as those described in DE4302555A1 (as assigned to Systems), and excimer lamps excited by volume discharge with ultraviolet pre-ionization, as described in Tech.Phys, 39(10), 1054 (1994). Excimer ultraviolet light sources often contain krypton bromide or krypton chloride. For example, deuterium lamps typically exhibit a broad peak bandwidth of about 200 nm to about 280 nm and have an emission spectrum that gradually decreases from about 280 nm to about 700 nm. device

[0081] In a third aspect, the Disclosure provides a device. The device is

[0082] a) A chamber comprising at least one wall,

[0083] b) A broadband UVC light source located inside the chamber,

[0084] c) An absorption layer adjacent to at least one wall of the chamber,

[0085] d) A UV mirror located in a chamber between a broadband UVC light source and an absorption layer, comprising at least a plurality of alternating first and second optical layers, wherein the UV mirror collectively reflects at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of 190 nanometers, 195 nm, or 200 nm to 230 nanometers, 235 nm, or 240 nm at at least one incident light angle among 0°, 15°, 30°, 45°, 60°, or 75°, and collectively transmits at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of over 230 nanometers, over 235 nm, or over 240 nm to 400 nanometers at at least one incident light angle among 0°, 15°, 30°, 45°, 60°, or 75°,

[0086] At least 50, 60, 70, 80, 90, or 95 percent of the ultraviolet light having wavelengths of at least 230 nanometers to 400 nanometers that passes through the ultraviolet mirror is absorbed within the chamber. Thus, wavelengths in the range of over 230 nm and 400 nm that pass through the ultraviolet mirror can bounce within the chamber until at least 50 percent of them are ultimately absorbed by the absorption layer and / or chamber walls. However, in some embodiments, the absorption layer absorbs at least 10, 20, 30, 40, 50, 60, 70, 80, 90, or 95 percent of the incident ultraviolet light having wavelengths of at least 230 nanometers to 400 nanometers.

[0087] The ultraviolet mirror and absorption layer are according to any embodiment of these parts of the multilayer article of the first embodiment described in detail above. The broadband UVC light source is according to any embodiment of the broadband UVC light source of the second embodiment described in detail above.

[0088] In some embodiments, the chamber for the device is in the form of a cabinet or enclosure equipped with a broadband UVC light source that illuminates the inside of the device and its contents with UVC light. The device can be, for example, square, rectangular, conical, parabolic, elliptical, spherical, or a combination of shapes and includes ultraviolet mirrors present in its internal region. UV reflection tends to minimize the absorption of desired wavelengths of UVC light before they are absorbed by the target microorganisms.

[0089] Referring to Figure 3, a schematic cross-sectional view of an exemplary device 300 is shown. The device 300 comprises a chamber 330 having at least one wall 332, a broadband UVC light source 320 located within the chamber 330, an absorption layer 314 adjacent to at least one wall 332 of the chamber 330, and an ultraviolet mirror 305 located within the chamber 330 between the broadband UVC light source 320 and the absorption layer 314. Typically, the broadband UVC light source 320 is positioned and / or configured to direct light towards the ultraviolet mirror 305.

[0090] In this embodiment, the absorption layer 314 is configured to follow the contour of at least one wall 332, for example, and is positioned adjacent to at least one wall 332. In some cases, the absorption layer 314 is directly adjacent to at least one wall 332. Optionally, the absorption layer 314 may be attached to at least one wall 332 by means of an adhesive or other fastening means. In addition, in this embodiment, the ultraviolet mirror 305 is positioned at a distance from the absorption layer 314. The ultraviolet mirror 305 may also have a different shape from the absorption layer 314, as shown in Figure 3, with the ultraviolet mirror 305 having a rounded shape and the absorption layer having a rectangular shape.

[0091] The material constituting at least one wall 332 of the chamber 330 is not particularly limited and may include, for example, metal, plastic, ceramic (including glass), concrete, or wood. In certain embodiments, at least one wall 332 is formed from a heat-resistant or heat-conductive material capable of withstanding the heat generated by the absorption of light of specific wavelengths from a broadband UVC light source within the chamber 330. Often, the chamber is configured to be sealed, including, by including an access port or door that can be opened to insert or remove material and closed to close and / or seal the chamber, thereby containing light of wavelengths reflected within the chamber. When the material is in the form of a liquid or gas (e.g., in a phase other than solid), the chamber may be configured to allow the material to be pumped (or otherwise transported) into and out of the chamber for disinfection.

[0092] Device 300 is shown to include, for example, material 340 to which reflected light wavelengths of 190 nm to 230 nm can be directed for disinfecting at least a portion of material 340. Such reflected wavelengths are schematically shown as dashed arrows in the chamber directed toward at least the surface of material 340. Preferably, any material that is also directly exposed to the emission of light from a broadband UVC light source is placed at least 3 cm, 3.25 cm, 3.5 cm, 3.75 cm, or at least 4 cm away from the broadband UVC light source to minimize exposure to wavelengths of light not reflected by the ultraviolet mirror 305. Some exemplary materials that can be disinfected using the exemplary chamber include, for example, medical instruments, sanitary articles, air, liquids (e.g., water or beverages), filter media, food preparation equipment (e.g., surfaces, cutting tools, mixing tools, or cooking utensils), and porous membranes.

[0093] In alternative embodiments not shown with device 300, the ultraviolet mirror and the absorption layer may be adjacent to each other and / or have essentially the same shape (for example, similar to the ultraviolet mirror 205 and absorption layer 214 shown in Figure 2). method

[0094] In a fourth aspect, the disclosure provides a method for disinfecting at least one material. The method is:

[0095] a) Obtaining a system according to the second embodiment or a device according to the third embodiment,

[0096] b) Directing UVC light from a broadband UVC light source onto an ultraviolet mirror,

[0097] c) Exposing at least one material to ultraviolet light in the wavelength range of 190 nanometers to 240 nanometers, wherein the ultraviolet light is reflected toward the at least one material by an ultraviolet mirror.

[0098] The system is according to any embodiment of the system of the second embodiment described in detail above. The device is according to any embodiment of the device of the third embodiment described in detail above. The broadband UVC light source is according to any embodiment of the broadband UVC light source of the second embodiment described in detail above.

[0099] In certain embodiments, step c) above is performed until a log2, log3, log4, or greater reduction of at least one microorganism on or within at least one material is achieved compared to the amount of at least one microorganism present before step c). As used herein, the term “microorganism” refers to any cell or particle having genetic material suitable for analysis or detection (e.g., bacteria, yeast, viruses, and bacterial endospores). The logarithmic reduction value (LRV) may be determined by measuring the number of microbial colonies present on or within the material before disinfection by the exemplary method, disinfecting the material using the method, measuring the number of colonies present on or within the material after disinfection, and then calculating the LRV based on the obtained colony count. The method for measuring the number of colony-forming units (cfus) on or within the material varies depending on the morphology of the particular material. For example, a solid may be wiped, or a liquid or gas may be sampled volumetrically (and concentrated if necessary). Cfus may be measured using, for example, culture-based methods, image detection methods, fluorescence-based detection methods, colorimetric detection methods, immunological detection methods, genetic detection methods, or bioluminescence-based detection methods. LRV is calculated using the following formula.

[0100] LRV = (cfu / logarithm of area or volume of material before disinfection) - (cfu / logarithm of area or volume of disinfected material)

[0101] Figure 4 presents a flowchart of an exemplary method comprising the steps of obtaining a system or device, directing UVC light from a broadband UVC light source to an ultraviolet mirror, and exposing at least one material to ultraviolet light in the wavelength range of 190 nanometers to 230 nanometers, wherein the ultraviolet light is reflected toward the at least one material by the ultraviolet mirror. Generally, the at least one material includes at least one of solid, liquid, or gas. When using a device in the method, the at least one material is typically placed inside the device's chamber when exposed to UVC light. As described above, in some cases it is preferable to expose the material to ultraviolet light having wavelengths from above 190 nm, 195 nm, or above 200 nm to 230 nm, 235 nm, or 240 nm.

[0102] In a preferred embodiment, during the method, one or more materials are exposed to 10, 8, 6, 5, 4, 3, 2, or 1 percent or less of ultraviolet light having wavelengths of 230 nanometers, 235 nm, or above 240 nm to 400 nanometers emitted by a broadband UVC source. This is achieved by the effective absorption of these wavelengths by the absorption layer and / or chamber, so that 90 percent or more of the ultraviolet light having wavelengths of 230 nanometers, 235 nm, or above 240 nm to 400 nanometers is absorbed during the method, instead of being directed to and / or reflected towards the material. Exemplary Embodiments

[0103] In a first embodiment, the disclosure provides a multilayer article comprising: a) an absorbing layer having a main surface that absorbs at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light having a wavelength of at least 230 nanometers to 400 nanometers; and b) an ultraviolet mirror adjacent to the main surface of the absorbing layer. The ultraviolet mirror comprises at least a plurality of alternating first and second optical layers that collectively reflect at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of 190 nanometers, 195 nm, or 200 nm to 230 nanometers, 235 nm, or 240 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, and collectively transmit at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of over 230 nanometers, over 235 nm, or over 240 nm to 400 nanometers at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°.

[0104] In a second embodiment, the disclosure provides a multilayer article according to the first embodiment, wherein the absorbent layer comprises a silicone thermoplastic resin, a fluoropolymer, a copolymer thereof, or a blend thereof.

[0105] In a third embodiment, the disclosure provides a multilayer article according to the first or second embodiment, wherein the absorbent layer comprises a fluoropolymer (co)polymer containing polymerization units derived from one or more monomers selected from tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, perfluoroalkoxyalkane, or a combination thereof.

[0106] In a fourth embodiment, the disclosure provides a multilayer article according to any of the first to third embodiments, wherein the absorbing layer further comprises one or more of the following: ultraviolet absorbers, ultraviolet scatterers, hindered amine light stabilizers, antioxidants, pigments, or combinations thereof.

[0107] In a fifth embodiment, the disclosure provides a multilayer article according to the fourth embodiment, wherein the ultraviolet absorber comprises at least one of carbon black, titanium dioxide, zinc oxide, cesium dioxide, or zirconium dioxide.

[0108] In a sixth embodiment, the disclosure provides a multilayer article according to a fourth or fifth embodiment, wherein the ultraviolet absorber comprises a benzotriazole compound, a benzophenone compound, a triazine compound, or a combination thereof.

[0109] In the seventh embodiment, the disclosure provides a multilayer article according to any of the first to sixth embodiments, wherein the absorbent layer comprises a continuous metal coating or layer.

[0110] In the eighth embodiment, the disclosure provides a multilayer article according to any of the first to sixth embodiments, wherein the absorbent layer comprises metal particles disposed in a polymer matrix.

[0111] In the ninth embodiment, the disclosure provides a multilayer article according to the seventh or eighth embodiment, wherein the metal is selected from silver, gold, copper, nickel, and titanium.

[0112] In the tenth embodiment, the disclosure provides a multilayer article according to any of the first to ninth embodiments, wherein the absorbing layer absorbs at least 30 percent, at least 40 percent, at least 50 percent, at least 60 percent, at least 70 percent, at least 80 percent, or at least 90 percent of incident visible light having wavelengths of at least 400 nanometers to 700 nanometers.

[0113] In the eleventh embodiment, the disclosure provides a multilayer article according to any of the first to tenth embodiments, wherein at least one first optical layer comprises zirconium oxynitride, hafnia, alumina, magnesium oxide, yttrium oxide, lanthanum fluoride, or neodymium fluoride, and the second optical layer comprises at least one of silica, aluminum fluoride, magnesium fluoride, calcium fluoride, silica-alumina oxide, or alumina-doped silica.

[0114] In the twelfth embodiment, the disclosure provides a multilayer article according to any of the first to tenth embodiments, wherein at least a first optical layer comprises at least one of polyvinylidene fluoride or polyethylene tetrafluoroethylene, and a second optical layer comprises fluorinated ethylene propylene (FEP) or a copolymer of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride.

[0115] In a thirteenth embodiment, the disclosure provides a multilayer article according to any of the first to twelfth embodiments, wherein the ultraviolet mirror absorbs at least 30 percent, at least 80 percent, at least 90 percent, at least 95 percent, or at least 98 percent of incident visible light having wavelengths of at least 400 nanometers to 700 nanometers at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°.

[0116] In a fourteenth embodiment, the disclosure provides a multilayer article according to the thirteenth embodiment, wherein the ultraviolet mirror comprises a pigment or dye.

[0117] In a 15th embodiment, the Disclosure provides a multilayer article according to any of the 1st to 14th embodiments, wherein the ultraviolet mirror reflects at least 80 percent, at least 90 percent, at least 95 percent, or at least 98 percent of incident ultraviolet light in the wavelength range of 190 nanometers, 195 nm, or 200 nm to 230 nanometers, 235 nm, or 240 nm, preferably 190 nm to 230 nm, 200 nm to 240 nm, or 200 nm to 230 nm, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°.

[0118] In the sixteenth embodiment, the disclosure provides a multilayer article according to any of the first to fifteenth embodiments, further comprising an adhesive layer adjacent to the absorbent layer, wherein the absorbent layer is positioned between the ultraviolet mirror and the adhesive layer.

[0119] In the 17th embodiment, the disclosure provides a multilayer article according to any of the 1st to 16th embodiments, wherein an ultraviolet mirror is directly attached to the absorption layer.

[0120] In the 18th embodiment, the disclosure provides a multilayer article according to any of the 1st to 16th embodiments, wherein the ultraviolet mirror is separated from the absorption layer by a void.

[0121] In the 19th embodiment, the disclosure provides a multilayer article according to any of the first to 18 embodiments, further comprising at least one of a heat transfer layer, a plurality of heat transfer fins, or a plurality of heat transfer pins adjacent to the main surface of the absorption layer on the side opposite to the ultraviolet mirror.

[0122] In the 20th embodiment, the disclosure provides a multilayer article according to any of the first to 19 embodiments having a hollow, non-planar shape.

[0123] In the 21st embodiment, the disclosure provides a multilayer article according to any of the first to 20th embodiments, wherein the main surface of the ultraviolet mirror comprises a plurality of non-planar features protruding from the main surface.

[0124] In the 22nd embodiment, the disclosure provides a system comprising a) a broadband UVC light source and b) a multilayer article according to any of the 1st to 21st or 36th embodiments.

[0125] In the 23rd embodiment, the disclosure provides a system according to the 22nd embodiment in which the broadband UVC light source is a low-pressure mercury lamp, a medium-pressure mercury lamp, a deuterium arc lamp, a xenon arc lamp, or an excimer lamp.

[0126] In the 24th embodiment, the disclosure provides a system according to the 22nd or 23rd embodiment, in which a broadband UVC light source is configured to direct light onto an ultraviolet mirror of a multilayer article.

[0127] In a 25th embodiment, the disclosure provides a device comprising: a) a chamber having at least one wall; b) a broadband UVC light source located within the chamber; c) an absorption layer adjacent to at least one wall of the chamber; and d) an ultraviolet mirror located within the chamber between the broadband UVC light source and the absorption layer. The ultraviolet mirror comprises at least a plurality of alternating first and second optical layers that collectively reflect at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of 190 nanometers, 195 nm, or 200 nm to 230 nanometers, 235 nm, or 240 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, and collectively transmit at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of over 230 nanometers, over 235 nm, or over 240 nm to 400 nanometers at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°. At least 50, 60, 70, 80, 90, or 95 percent of the ultraviolet light with wavelengths of at least 230 nanometers to 400 nanometers that passes through the ultraviolet mirror is absorbed within the chamber.

[0128] In the 26th embodiment, the disclosure provides a device according to the 25th embodiment, wherein the absorbing layer absorbs at least 10, 20, 30, 40, 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light having wavelengths of at least 230 nanometers to 400 nanometers.

[0129] In the 27th embodiment, the disclosure provides a device according to the 25th or 26th embodiment, in which a broadband UVC light source is configured to direct light to an ultraviolet mirror.

[0130] In the 28th embodiment, the disclosure provides a device according to any of the 25th to 27th embodiments, wherein the ultraviolet mirror and the absorption layer are separated from each other.

[0131] In the 29th embodiment, the disclosure provides a device according to any of the 25th to 28th embodiments, wherein the absorption layer is directly adjacent to at least one wall of the chamber.

[0132] In a 30th embodiment, the Disclosure provides a method for disinfecting at least one material. The method includes a) obtaining a system according to any of the 22nd to 24th embodiments or a device according to any of the 25th to 29th embodiments; b) directing UVC light from a broadband UVC light source towards an ultraviolet mirror; and c) exposing at least one material to ultraviolet light in the wavelength range of 190 nanometers to 240 nanometers, wherein the ultraviolet light is reflected toward the at least one material by the ultraviolet mirror.

[0133] In the 31st embodiment, the disclosure provides a method according to the 30th embodiment, wherein at least one material comprises at least one of a solid, a liquid, or a gas.

[0134] In the 32nd embodiment, the disclosure provides a method according to the 30th or 31st embodiment, in which at least one material is placed inside the chamber of the device.

[0135] In the 33rd embodiment, the disclosure provides a method according to any of the 30th to 32nd embodiments, wherein step c) is carried out until a log2, log3, log4 or greater reduction of at least one microorganism on or within at least one material is achieved compared to the amount of at least one microorganism present before step c).

[0136] In the 34th embodiment, the disclosure provides a method according to any of the 30th to 33rd embodiments, in which at least one material is exposed to 10, 8, 6, 5, 4, 3, 2, or 1 percent or less of ultraviolet light having a wavelength between 230 nanometers and 400 nanometers, emitted by a broadband UVC source.

[0137] In a 35th embodiment, the Disclosure provides a system comprising a UVC collimator, a broadband UVC light source, and a multilayer article having a UVC mirror and an absorbing layer. The multilayer article is positioned adjacent to the ceiling of a room, and the UVC collimator is configured to collimate light from the broadband UVC light source and direct the collimated light at a certain angle toward the UVC mirror of the multilayer article adjacent to the ceiling. The absorbing layer absorbs at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light having wavelengths of at least 230 nanometers to 400 nanometers. The absorbing layer has a main surface, and the ultraviolet mirror is adjacent to the main surface of the absorbing layer. The ultraviolet mirror consists of at least a plurality of alternating first and second optical layers that collectively reflect at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of 200 nm to 230 nanometers, 235 nm, or 240 nm, and collectively transmit at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light in the wavelength range of over 230 nanometers, over 235 nm, or over 240 nm to 400 nanometers at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°.

[0138] In the 36th embodiment, the Disclosure provides a multilayer article according to any of the 1st to 9th or 11th to 21st embodiments, wherein the absorbing layer reflects at least 30 percent, at least 40 percent, at least 50 percent, at least 60 percent, at least 70 percent, at least 80 percent, or at least 90 percent of incident visible light having wavelengths of at least 400 nanometers to 700 nanometers.

[0139] The advantages and embodiments of the present invention will be further described by the following examples, but the specific materials and their quantities, as well as other conditions and details, described in these examples should not be construed as unduly limiting the invention. All parts and percentages are by weight unless otherwise indicated. Examples

[0140] Example 1

[0141] UVC mirrors reflecting wavelengths in the 200-240 nm range were fabricated by vapor coating an inorganic optical laminate having a first optical layer containing HfO2 and a second optical layer containing SiO2 onto a 100 micrometer (4 mil) thick fluoropolymer film (obtained from Nowofol Kunststoffprodukte GmbH&Co.KG (Siegsdorf, Germany) under the trade name "NOWOFLON THV 815"). More specifically, a thin film laminate consisting of alternating layers of HfO2 and SiO2, designed to have a peak reflectivity at 200 nm, was started by coating layer 1 with HfO2 at 23.5 nm. For electron beam deposition, four hearths were used as deposition sources. Each hearth was conical in shape and had a volume of 17 cm³. 3A mass of HfO2 was packed into the substrate. A magnetically deflected high-voltage electron beam was raster-scanned across the material surface while gradually increasing the beam's filament current in a pre-programmed manner. Once the pre-programmed process was complete, the HfO2 surface was heated to approximately 2500°C, the deposition temperature, and the source shutter opened. The HfO2 vapor flux exited the source in a cosine distribution and condensed onto the substrate material above the source. To improve coating uniformity, the substrate holder was rotated during deposition. Once a predetermined coating thickness (23.5 nm) was reached, the filament current was cut off, the shutter closed, and the HfO2 material was cooled. For layer 2, the deposition source was then rotated to a hearth containing a mass of SiO2, and a similar pre-programmed heating process was initiated. Here, the SiO2 surface temperature was approximately 950°C when the supply shutter was open. Once a predetermined coating thickness (34.2 nm) was reached, the filament current was cut off, the shutter closed, and the SiO2 material was cooled. This stepwise process was continued layer by layer until a total of 11 layers were reached. Reflectance was measured using a spectrophotometer (obtained from Perkin-Elmer (Waltham, MA) under the trade name "LAMBDA 1050 UV-VIS"), and it was found to be 97.9% at 222 nm and 18.2% at 254 nm.

[0142] The UV-absorbing film was prepared by extruding 30 wt% TiO2 (obtained from Americhem Co. (Cuyahoga Falls, OH)) with a fluoropolymer (obtained from 3M (St. Paul, MN) under the trade name "3M DYNEON THV 500GZ") and casting it onto a cooling roll at 24 feet / min (7.32 m / min) to a film with a thickness of 200 micrometers.

[0143] Next, the UVC mirror film was heat-laminated to a UV-absorbing fluoropolymer film in a 130°C oven at a weight of 5 pounds (2.27 kg) for 2 hours. When this heat-laminated UV mirror film laminate was measured with a spectrophotometer (LAMBDA 1050 UV-VIS), it had an average reflectance (%) of 89.9% over the wavelength range of 200 nm to 240 nm, as shown in Figure 5.

[0144] Example 2 - Prediction

[0145] A UVC mirror film that reflects light in the range of 200-240nm is made of ZrO x N y A first optical layer containing SiAl x O y An inorganic optical laminate having a second optical layer containing a fluoropolymer film (available from Nowofol Kunststoffprodukte GmbH&Co.KG (Siegsdorf, Germany) under the trade name "NOWOFLON THV 815") was fabricated by sputter coating. ZrO was used as the high refractive index material. x N y SiAl as a low refractive index material x O y Using this, UVC mirror films can be coated in a continuous roll-to-roll (R2R) manner. The optical design was adjusted to create a layer thickness gradient by alternating layers of two materials with a quarter-wavelength thickness, starting reflection at 200 nm and the last layer of the laminate reflecting at 240 nm. ZrO has a refractive index of 3.1 at 200 nm. x N y The physical thickness target is 17.74 nm. Here, SiAl with a refractive index of 1.57 is sputtered from an aluminum-doped silicon sputtering target. x O y The target thickness for layer 1 is 35 nm. x N yThe film is DC sputtered from a pure zirconium sputtering target in a mixture of argon, oxygen, and nitrogen gases. Argon is the primary sputtering gas, while the levels of oxygen and nitrogen are set to achieve transparency, low absorptivity, and high refractive index. The film roll is initially transported at a predetermined speed, the sputtering source power is increased to maximum operating power, followed by the introduction of reactive gases, and then to a steady state. The sputtering source is perpendicular to and wider than the film being coated. Once the coated film reaches the desired length, the reactive gas is set to zero and the target is sputtered to yield a pure Zr surface state. Next, the film direction is reversed, and silicon (aluminum-doped) is placed using a pair of rotary sputtering targets with AC frequency (40 kHz) power applied in an argon sputtering atmosphere. Once a steady state is reached, oxygen reactive gas is introduced to yield transparency and a low refractive index. The second layer is coated over the length coated by the first layer at predetermined process settings and line speeds. The sputtering source is perpendicular to and wider than the film being coated. After the coated film reaches the desired length, the target is sputtered in argon to remove reactive oxygen and result in a pure silicon (aluminum-doped) surface state. This stepwise process is continued layer by layer until a total of nine layers are reached. The resulting peak reflectance, measured with a spectrophotometer ("LAMBDA 1050 UV-VIS"), is expected to be 95% at 222 nm and decrease to a lower reflectance of 20% at 254 nm. The UV-absorbing film can be fabricated by extruding 30 wt% TiO2 (available from Americhem (Cuyahoga Falls, OH)) with the fluoropolymer "3M DYNEON THV 500GZ" and casting it onto a cooling roll at 10 feet / min (3.05 m / min) to a film with a thickness of 200 micrometers. Next, the UVC mirror film can be heat-laminated onto the UV-absorbing fluoropolymer film in an oven at 130°C for 2 hours at a weight of 5 pounds (2.27 kg).This heat-laminated UV mirror film laminate is expected to have an average reflectance (%) of 89.9% over the wavelength range of 200 nm to 240 nm, as measured by a spectrophotometer ("LAMBDA 1050 UV-VIS").

[0146] Example 3

[0147] Referring to Figure 6, a UVC disinfection system 600 comprising a multilayer article 601 and a UVC light source 603 (MICROBEBUSTER available from Sterilray (Somersworth, NH)) was fabricated according to the present disclosure. The multilayer article 601 contained a UVC mirror film 601a fabricated as described in Example 1, but instead of using a TiO2-filled THV500 UVC absorbing layer, a 125-micrometer-thick layer 601b of UVC-absorbing polyester film available from DuPont Teijin Films US Limited Partnership (Chester, VA) under the trade name MELINEX ST505 was used in the multilayer article 601. The UVC mirror film 601a having a reflectivity band of 200-240 nm was mounted on a substrate of polyester film 601b that absorbs UVC in the range of 200-320 nm. The multilayer article 601 was positioned at a 45-degree angle to the aperture from which light is emitted from the UVC light source 603, so as to reflect the 200-240 nm UVC wavelength emitted by the UVC light source 603 to the opposite side of the second multilayer article 602, which is positioned parallel to and spaced apart from the first multilayer article 601 (positioned so that the UVC light is directed toward the UVC mirror film 601a). The second multilayer article 602 included a UVC mirror film 602a having a reflectivity band of 200-240 nm, mounted on a polyester film 602b substrate that absorbs UVC in the range of 200-320 nm, and was manufactured in the same manner as the first multilayer film 601, and positioned so that the UVC light reflected from the first multilayer article 601 is directed toward the UVC mirror film 602a. The multilayer articles 601 and 602 were 24 inches (60.96 centimeters) long and 12 inches (30.48 centimeters) wide, respectively, in the longitudinal direction of the UVC light source 603. The second UVC mirror film 602 reflects 222 nm UVC light 604 downwards, and less 254 nm UVC light is reflected downwards. The ratio of 222 nm to 254 nm UVC intensity measured after reflection from the two multilayer articles 601 and 602 at a UVC photosensor 605 located 76 cm below the UVC light source 603 was 30.9.In the absence of the two multilayer articles 601 and 602, the ratio of UVC intensity at 222 nm to 254 nm, measured under 76 cm of the UVC light source 603, was 15.8. Double reflection of UVC light from UVC mirror films (each UVC mirror film having UVC absorption of 200-320 nm) increased the UVC intensity ratio at 222 nm to 254 nm by 95%.

[0148] Foreseeable modifications and changes to the present invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. The present invention is not limited to the embodiments described herein for illustrative purposes.

Claims

1. A multilayer article comprising an ultraviolet mirror into which ultraviolet light is incident, and an absorbing layer into which light that has passed through the ultraviolet mirror is incident, The ultraviolet mirror has a reflectance of incident ultraviolet light integrated over a wavelength range from 190 nm, 195 nm, or 200 nm to 230 nm, 235 nm, or 240 nm at at least one incident light angle among 0°, 15°, 30°, 45°, 60°, or 75°, and a transmittance of incident ultraviolet light integrated over a wavelength range from over 230 nm, over 235 nm, or over 240 nm to 400 nm at at least one incident light angle among 0°, 15°, 30°, 45°, 60°, or 75°, and is composed of at least a plurality of alternating first and second optical layers. A multilayer article wherein the absorbing layer has an integrated absorption rate over a wavelength range of 230 nm to 400 nm with respect to light transmitted through the ultraviolet mirror, which is at least 50, 60, 70, 80, 90, or 95 percent.

2. The multilayer article according to claim 1, wherein the absorbent layer comprises a silicone thermoplastic resin, a fluoropolymer, a copolymer thereof, or a blend thereof.

3. The multilayer article according to claim 1 or 2, wherein the absorbing layer further comprises one or more of the following: an ultraviolet absorber, an ultraviolet scattering agent, a hindered amine light stabilizer, an antioxidant, a pigment, or a combination thereof.

4. The multilayer article according to any one of claims 1 to 3, wherein the absorbing layer comprises a continuous metal coating or layer, or the absorbing layer comprises metal particles disposed in a polymer matrix.

5. The multilayer article according to any one of claims 1 to 4, wherein the absorption layer has an absorbance of incident visible light integrated over a wavelength range of 400 nm to 700 nm of at least 30 percent, at least 40 percent, at least 50 percent, at least 60 percent, at least 70 percent, at least 80 percent, or at least 90 percent, or the reflectance of incident visible light integrated over a wavelength range of 400 nm to 700 nm of at least 30 percent, at least 40 percent, at least 50 percent, at least 60 percent, at least 70 percent, at least 80 percent, or at least 90 percent.

6. A multilayer article according to any one of claims 1 to 5, wherein the at least first optical layer comprises at least one of zirconium oxynitride, hafnia, alumina, magnesium oxide, yttrium oxide, lanthanum fluoride, or neodymium fluoride, and the second optical layer comprises at least one of silica, aluminum fluoride, magnesium fluoride, calcium fluoride, silica-alumina oxide, or alumina-doped silica.

7. The multilayer article according to any one of claims 1 to 6, further comprising, adjacent to the absorption layer on the opposite side of the ultraviolet mirror, at least one of a heat transfer layer, a plurality of heat transfer fins, or a plurality of heat transfer pins.

8. A multilayer article according to any one of claims 1 to 7, having a hollow, non-planar shape.

9. The multilayer article according to claim 1, wherein the absorbing layer absorbs 70 percent or more of the incident visible light in the wavelength range of at least 400 nm to 700 nm.

10. a) A broadband UVC light source, b) A multilayer article according to any one of claims 1 to 9, A system equipped with these features.

11. The system according to claim 10, wherein the broadband UVC light source is configured to direct light onto the ultraviolet mirror of the multilayer article.

12. a) A chamber comprising at least one wall, b) A broadband UVC light source located within the chamber, c) An absorption layer adjacent to at least one wall of the chamber, d) A UV mirror located in the chamber between the broadband UVC light source and the absorption layer, comprising at least a plurality of alternating first and second optical layers, wherein the reflectance of incident ultraviolet light integrated over a wavelength range from 190 nm, 195 nm, or 200 nm to 230 nm, 235 nm, or 240 nm at at least one incident light angle among 0°, 15°, 30°, 45°, 60°, or 75° is at least 50, 60, 70, 80, 90, or 95 percent, and the transmittance of incident ultraviolet light integrated over a wavelength range from above 230 nm, above 235 nm, or above 240 nm to 400 nm at at least one incident light angle among 0°, 15°, 30°, 45°, 60°, or 75° is at least 50, 60, 70, 80, 90, or 95 percent, A device wherein the absorption rate within the chamber, integrated over a wavelength range of 230 nm to 400 nm with respect to light transmitted through the ultraviolet mirror, is at least 50, 60, 70, 80, 90, or 95 percent.

13. The device according to claim 12, wherein the ultraviolet mirror and the absorption layer are separated from each other.

14. The device according to claim 12, wherein the absorption layer absorbs 70 percent or more of the incident visible light in the wavelength range of at least 400 nm to 700 nm.

15. A method for disinfecting at least one material, a) Obtaining the system described in claim 10 or 11 or the device described in any one of claims 12 to 14, b) Directing UVC light from the broadband UVC light source onto the ultraviolet mirror, c) Exposing the at least one material to ultraviolet light in the wavelength range of 190 nm, 195 nm, or 200 nm to 230 nm, 235 nm, or 240 nm, wherein the ultraviolet light is reflected toward the at least one material by the ultraviolet mirror. A method that includes this.

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