Light-shielding article, electromagnetic receiver and / or emitter including the same

Abstract

A light-shielding article is provided. The light-shielding article includes a first multilayer optical film composed of alternating first and second polymer optical layers that collectively reflect, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, on average, at least 70, 80, 90, or 95 percent of incident visible light over a wavelength range of at least 400 nanometers (nm) to 700 nm. The light-shielding article further includes either a second multilayer optical film or a barrier coating disposed on the first multilayer optical film. The light-shielding article transmits, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, on average, at least 70, 80, 90, or 95 percent of incident radio frequency waves within at least one wavelength range of 1 mm to 10 mm, 10 mm to 100 mm, or 100 mm to 1000 mm. Further, an electromagnetic receiver and / or emitter is provided, and the electromagnetic receiver and / or emitter includes a light-shielding article attached to at least a portion of the electromagnetic receiver and / or emitter.

Description

Background Art

[0001] There is a class of telecommunications networks that have an infrastructure provided by a constellation of thousands of small satellites deployed in low Earth orbit. These satellites transmit and receive electromagnetic telecommunications signals using antennas. These antennas generate a significant amount of heat during operation and are further heated by exposure to solar radiation. In space where the presence of gas particles is minimal and common heat management effects such as convection cannot occur, it is difficult to manage this heat. One measure that helps with heat management is to cover the satellite with a reflective film that blocks solar energy, thereby blocking a large heat energy source. However, the devices typically operate at altitudes in the range of 20 - 2000 km, where the atmosphere is thin and absorbs little solar radiation. Therefore, high-altitude devices are exposed to a stronger AM0 solar spectrum and high-intensity ultraviolet (UV) radiation, particularly UV-C radiation, than is present in the AM1.5 solar spectrum encountered under Earth's surface conditions. High-altitude devices may also be exposed to atomic oxygen, which can damage oxygen-sensitive electronic components.

Summary of the Invention

[0002] In a first aspect, a light-shielding article is provided. The light-shielding article includes: a) a first multilayer optical film comprising at least a plurality of alternating first and second polymer optical layers that collectively reflect, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, on average at least 70, 80, 90, or 95 percent of incident visible light over a wavelength range of at least 400 nanometers (nm) to 700 nm, the first multilayer optical film having a first major surface; and b) a second multilayer optical film disposed on the first multilayer optical film, the second multilayer optical film comprising at least a plurality of alternating first and second inorganic optical layers that collectively reflect and absorb, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, on average at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light over a reflection bandwidth of at least 30 nanometers at a wavelength within the wavelength range of 190 nm to 400 nm. The light-shielding article transmits, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, on average at least 70, 80, 90, or 95 percent of incident radio frequency waves within at least one wavelength range of 1 millimeter (mm) to 10 mm, 10 mm to 100 mm, or 100 mm to 1000 mm.

[0003] In a second aspect, another light-shielding article is provided. This light-shielding article comprises: a) a first multilayer optical film comprising at least a plurality of alternating first and second polymer optical layers that collectively reflect, on average, at least 70, 80, 90, or 95 percent of incident visible light in the wavelength range of at least 400 nanometers (nm) to 700 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, the first multilayer optical film having a first major surface; and b) a barrier coating disposed on the first major surface of the multilayer optical film, the barrier coating comprising at least one dyad comprising a (co)polymer layer overlapping the first major surface of the multilayer optical film and an inorganic layer overlapping the (co)polymer layer, an outer (co)polymer layer overlapping the at least one dyad, and optionally at least one outer inorganic layer overlapping the outer (co)polymer layer. This light-shielding article transmits, on average, at least 70, 80, 90, or 95 percent of incident radio frequency waves in at least one wavelength range of 1 mm to 10 mm, 10 mm to 100 mm, or 100 mm to 1000 mm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°. This light-shielding article transmits, on average, a maximum of 50, 60, or 70 percent of incident ultraviolet light over a reflection bandwidth of at least 30 nanometers at wavelengths in the wavelength range of 190 nm to 400 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°.

[0004] In a third aspect, an electromagnetic receiver and / or emitter is provided. This electromagnetic receiver and / or emitter comprises a light-shielding article according to the first or second aspect attached to at least a portion of the electromagnetic receiver and / or emitter.

[0005] Various unexpected results and advantages are obtained in the exemplary embodiments of the present disclosure. One such advantage of the exemplary embodiments of the present disclosure is the provision of an article that provides shielding from wavelengths within both the visible range and the UV range while allowing transmission of wavelengths within the radio frequency (RF) range. In some cases, the light-shielding article according to the present disclosure provides broadband shielding in the UV range, the visible range, or both.

[0006] Furthermore, the light-shielding article including the barrier coating provides protection from an atomic oxygen environment. In addition, by combining UV absorption and reflection in a light-shielding article including a second multilayer optical film, a broadband UV blocking filter made of a durable inorganic material that can survive in low Earth orbit conditions is created. These layers can be sputter deposited or evaporated in a roll-to-roll process. Thus, a further advantage of the exemplary embodiments is to enable a high-speed roll-to-roll continuous manufacturing process for at least some embodiments of the light-shielding articles of the present disclosure.

[0007] The above is an overview of the various aspects and advantages of the exemplary embodiments of the present disclosure. The above "Summary of the Invention" is not intended to describe each illustrated embodiment or all implementation forms of an exemplary embodiment of the present disclosure. The following drawings and "Detailed Description of the Invention" illustrate some preferred embodiments using the principles disclosed herein in more detail.

Brief Description of the Drawings

[0008] The present disclosure can be more fully understood by considering the following detailed description of various embodiments of the present disclosure in conjunction with the accompanying drawings.

[0009]

Figure 1

[0010]

Figure 2

[0011] In the drawings, like reference numerals indicate like elements. The drawings identified above may not be drawn to scale and illustrate various embodiments of the present disclosure, but as pointed out in the "Detailed Description of the Invention," other embodiments are also contemplated. In all cases, the present disclosure describes the disclosed content herein by way of exemplary embodiments rather than by explicit limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that fall within the scope and spirit of the present disclosure.

Detailed Description of the Invention

[0012] Regarding the glossary of the following defined terms, these definitions shall apply throughout the present application unless different definitions are provided in the claims or elsewhere in this specification. Glossary

[0013] Certain terms are used throughout this specification and the claims, and while most of them are well-known, some may require explanation. Please understand the following:

[0014] The term "fluoropolymer" refers to any organic polymer containing fluorine.

[0015] The term "non-fluorinated" means not containing fluorine.

[0016] The term "(co)polymer" includes homopoly(co)polymers and copolymers, as well as homopoly(co)polymers or copolymers that can be formed in miscible blends (e.g., by coextrusion or by a reaction involving, for example, a transesterification reaction). The term "(co)polymer" includes random, block, and star (co)polymers.

[0017] As used herein, "adjacent" encompasses both being in direct contact (e.g., directly adjacent) and having one or more intermediate layers present between the adjacent materials.

[0018] As used herein, "incident" with respect to light refers to light shining on or hitting a material.

[0019] The term "crosslinked" (co)polymer refers to a (co)polymer in which its (co)polymer chains are linked to each other by chemical covalent bonds, usually by crosslinking molecules or groups, to form a network (co)polymer. Crosslinked (co)polymers are generally characterized by insolubility but can be swellable in the presence of a suitable solvent.

[0020] The term "curing" refers to a chemical change (e.g., a process that generates covalent bonds to solidify a multilayer film layer or causes a reaction that increases its viscosity).

[0021] The term "cured" (co)polymer includes both crosslinked and non-crosslinked (co)polymers.

[0022] The term "metal" includes pure metals or metal alloys.

[0023] The term "film" or "layer" refers to a single layer within a multilayer film.

[0024] The terms “(meth)acryl” or “(meth)acrylate” with respect to a monomer, oligomer, (co)polymer or compound mean a vinyl-functional alkyl ester formed as a reaction product of an alcohol with acrylic acid or methacrylic acid.

[0025] The term “optically clear” refers to an article that is free of visually detectable distortion, haze, or defects that can be detected by the naked eye at a distance of about 1 meter, preferably about 0.5 meter.

[0026] The term “optical thickness,” when used with respect to a layer, refers to the physical thickness of the layer multiplied by the in-plane refractive index.

[0027] The terms “vapor coating” or “vapor deposition” mean applying a coating to a substrate surface from the gas phase, for example, by evaporating a coating precursor material or the coating material itself and subsequently depositing it on the substrate surface. Exemplary vapor coating processes include, for example, physical vapor deposition (PVD), chemical vapor deposition (CVD), and combinations thereof.

[0028] To describe the position of one layer relative to a dyad or different layers of the articles of the present disclosure, use of the terms “overlaying” or “overcoated” is used to indicate that the layer is over the dyad or different layer, but not necessarily adjacent or in contact with the dyad or different layer, although in some embodiments it may be in direct contact with the dyad or other layer.

[0029] The relative position of an element with respect to a horizontally disposed upward substrate is referred to by using orientation terms such as "atop", "on", "over", "covering", "uppermost", "underlying", etc. regarding the location of various elements in the coated articles of the present disclosure. However, unless otherwise indicated, the substrate or article is not intended to have any particular orientation in space during or after manufacture or in the interpretation of the claims.

[0030] As used herein, "radiation" refers to electromagnetic radiation unless otherwise specified.

[0031] 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.

[0032] As used herein, "reflectivity" is a measure of the proportion of light or other radiation reflected when incident on a surface at normal incidence. Reflectance typically varies with wavelength and is reported as a percentage of the incident light reflected from the surface (0 percent - no reflected light, 100 - all light is reflected). Reflectance and reflectivity are used interchangeably herein.

[0033] As used herein, "reflective" and "reflectance" refer to the property of reflecting light or radiation, particularly the reflectivity measured independently of the thickness of the material.

[0034] As used herein, "average reflectivity" refers to the reflectivity averaged over a specific wavelength range.

[0035] As used herein, "absorption" refers to the conversion of the energy of light radiation into internal energy by a material.

[0036] As used herein, "absorbing" with respect to the wavelength of light includes both absorption and scattering since scattered light is ultimately also absorbed. Absorbance can be measured by 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 conducting transmission measurements as described above and then calculating the absorbance using Equation 1.

[0037] As used herein, the term "absorbance" with respect to quantitative measurements refers to the base 10 logarithm of the ratio of the incident radiant flux to the radiant flux transmitted through the material. This ratio can be described as the value obtained by dividing the radiant flux received by the material by the radiant flux transmitted by the material. Absorbance (A) can be calculated according to the following Equation 1 based on the internal transmittance (T): A = -log 10 T (1)

[0038] 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 Emissibity Using Infrared Imaging Radiometers". According to Kirchhoff's law of thermal radiation, absorbance correlates with emissive power. Absorbance, absorptivity, emissivity, and emittance are used interchangeably herein for the same purpose of emitting infrared energy to the atmosphere. "Absorbing" and "emitting" are also used interchangeably herein.

[0039] As used herein, the terms "transmittance" and "transmission" refer to the ratio of the total transmission through a layer of material compared to the total transmission received by the material, and can account for effects such as absorption, scattering, and reflection. The transmittance (T) may range from 0 to 1, or may be expressed as a percentage (T%).

[0040] As used herein, "transparent" refers to a material (e.g., a film or layer) that absorbs less than 20% of light having wavelengths from 350 nm to 2500 nm.

[0041] As used herein, "bandwidth" refers to the width of a continuous wavelength band.

[0042] The terms "about" or "substantially" with respect to a numerical value or shape mean plus or minus 5 percent of that numerical value or property or feature, but also explicitly include the exact numerical value.

[0043] The term "substantially" with respect to a property or feature means that the property or feature is exhibited to a higher degree than would be indicated by the presence of something that is the opposite of that property or feature. For example, a "substantially" transparent substrate refers to a substrate through which more of the incident radiation (e.g., visible light) is transmitted than is not transmitted (e.g., absorbed and reflected). Thus, a substrate that transmits more than 50% of the visible light incident on its surface is substantially transparent, while a substrate that transmits 50% or less of the visible light incident on its surface is not substantially transparent.

[0044] As used in this specification and the appended embodiments, the singular forms "a", "an", and "the" include plural referents unless the content clearly dictates otherwise. Thus, for example, a reference to a microfiber containing "a compound" includes mixtures of two or more compounds. As used in this specification and the appended embodiments, the term "or" is generally used in the sense of "and / or" unless the content clearly dictates otherwise.

[0045] Unless otherwise indicated, all numbers expressing quantities or ingredients, properties measured, and so forth used in this specification and the embodiments are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached list of embodiments are subject to change depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings of the present disclosure. At the very least, each numerical parameter should be construed in light of the reported number of significant digits and by applying ordinary rounding techniques, but this is not intended to limit the application of the doctrine of equivalents to the scope of the claimed embodiments.

[0046] By definition, the total weight percentage of all components in a composition equals 100 weight percent.

[0047] Next, various exemplary embodiments of the present disclosure will be described. The exemplary embodiments of the present disclosure can be subjected to various modifications and changes without departing from the spirit and scope of the present disclosure. Therefore, it should be understood that the embodiments of the present disclosure are not limited to the exemplary embodiments described below, but are regulated by the limitations set forth in the claims and any equivalents thereof. Light-shielding article

[0048] In a first aspect, a light-shielding article is provided. The light-shielding article includes: a) a first multilayer optical film comprising at least a plurality of alternating first and second polymer optical layers that collectively reflect, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, on average, at least 70, 80, 90, or 95 percent of incident visible light in the wavelength range of at least 400 nanometers (nm) to 700 nm, the first multilayer optical film having a first major surface;

[0049] b) A second multilayer optical film disposed on the first multilayer optical film, which collectively reflects and absorbs at least 50, 60, 70, 80, 90, or 95 percent, on average, of incident ultraviolet light over a reflection bandwidth that is at least 30 nanometers in wavelength within the wavelength range of 190 nm to 400 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, and comprising at least a plurality of alternating first and second inorganic optical layers,

[0050] This light-shielding article transmits, on average, at least 70, 80, 90, or 95 percent of incident radio frequency waves within at least one wavelength range of 1 millimeter (mm) to 10 mm, 10 mm to 100 mm, or 100 mm to 1000 mm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°.

[0051] Referring now to FIG. 1, the present disclosure describes a light-shielding article 10 including a first multilayer optical film 20 and a second multilayer optical film 30 disposed on a first major surface 21 of the first multilayer optical film 20. The first multilayer optical film 20 includes at least a plurality of alternating first polymer optical layers 23(A-N) and second polymer optical layers 22(A-N) that collectively reflect, on average, at least 70, 80, 90, or 95 percent of incident visible light in a wavelength range of at least 400 nanometers (nm) to 700 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°. The second multilayer optical film 30 includes at least a plurality of alternating first inorganic optical layers 33(A-N) and second inorganic optical layers 32(A-N) that collectively reflect and absorb, on average, at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light over a reflection bandwidth that is at least 30 nanometers in wavelength within a wavelength range of 190 nm to 400 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°. The light-shielding article 10 transmits, on average, at least 70, 80, 90, or 95 percent of incident radio frequency waves in at least one wavelength range of 1 millimeter (mm) to 10 mm, 10 mm to 100 mm, or 100 mm to 1000 mm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°.

[0052] In the light-shielding article shown in FIG. 1, an optional substrate 14 is attached to at least a part of the second main surface 25 of the first multilayer optical film 20. Such a substrate 14 can be attached directly, or at least one intermediate layer 12 can be disposed between the substrate 14 and the first multilayer optical film 20 so that the substrate 14 is indirectly attached. Suitable intermediate layers 12 include, for example, but are not limited to, tie layers, organic basecoat layers, barrier layers, or any combination thereof. In some preferred embodiments, the intermediate layer 12 is an adhesive layer (e.g., a tie layer). For example, the adhesive 12 may be disposed on at least a part of the second main surface 25 of the first multilayer optical film 20, or the adhesive may be disposed on at least a part of the substrate 14 facing the first multilayer optical film 20, or both. As shown in FIG. 1, there are an adhesive 12, an adhesive 16, and a substrate 14 disposed between the two adhesives.

[0053] In a second aspect, another light-shielding article is provided. This light-shielding article comprises: a) a first multilayer optical film comprising at least a plurality of alternating first and second polymer optical layers that collectively reflect, on average, at least 70, 80, 90, or 95 percent of incident visible light in the wavelength range from at least 400 nanometers (nm) to 700 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, the first multilayer optical film having a first main surface;

[0054] b) a barrier coating disposed on the first main surface of the multilayer optical film, the barrier coating comprising at least one diad comprising a (co)polymer layer overlapping the first main surface of the multilayer optical film and an inorganic layer overlapping the (co)polymer layer, and an outer (co)polymer layer overlapping the at least one diad, and optionally at least one outer inorganic layer overlapping the outer (co)polymer layer.

[0055] This light-shielding article transmits, on average, at least 70, 80, 90, or 95 percent of incident radio frequency waves within at least one wavelength range of 1 mm to 10 mm, 10 mm to 100 mm, or 100 mm to 1000 mm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°. This light-shielding article transmits, on average, at most 50, 60, or 70 percent of incident ultraviolet light over a reflection bandwidth that is at least 30 nanometers in wavelength within a wavelength range of 190 nm to 400 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°.

[0056] Referring now to FIG. 2, the present disclosure describes a light-shielding article 10 that includes a first multilayer optical film 20 and a barrier coating 50 disposed on a first major surface 21 of the first multilayer optical film 20. The first multilayer optical film 20 collectively reflects, on average, at least 70, 80, 90, or 95 percent of incident visible light over a wavelength range of at least 400 nanometers (nm) to 700 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, and includes at least a plurality of alternating first polymer optical layers 23(A-N) and second polymer optical layers 22(A-N). The barrier coating 50 includes at least one dyad 53 that includes a (co)polymer layer 52 that overlays the first major surface 21 of the multilayer optical film 20 and an inorganic layer 54 that overlays the (co)polymer layer 52. The barrier coating 50 further includes an outer (co)polymer layer 56 that overlays the at least one dyad 53 and, optionally, at least one outer inorganic layer 58 that overlays the outer (co)polymer layer 56. When used in the context of the barrier coating, "outer" refers to the outermost layer of a particular type of layer within the barrier coating, rather than the outermost layer of the entire light-shielding article (e.g., the outer (co)polymer layer or the outer inorganic layer).

[0057] In the embodiment shown in FIG. 2, the light-shielding article further includes a second multilayer optical film 30 disposed on the barrier coating 50 (e.g., on the outer (co)polymer layer 56 or on an optional outer inorganic layer 58 overlapping the outer (co)polymer layer 56). The second multilayer optical film 30 collectively reflects and absorbs at least 50, 60, 70, 80, 90, or 95 percent, on average, of the incident ultraviolet light over a reflection bandwidth that is at least 30 nanometers in wavelength within the wavelength range of 190 nm to 400 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°. It consists of at least a plurality of alternating first inorganic optical layers 33(A-N) and second inorganic optical layers 32(A-N).

[0058] In the light-shielding article shown in FIG. 2, an optional substrate 14 is attached to at least a part of the second major surface 25 of the first multilayer optical film 20. In addition, as shown in FIG. 2, an optional adhesive 16 is disposed on at least a portion of the substrate 14 on the side opposite the first multilayer optical film 20.

[0059] Advantageously, often this light-shielding article exhibits atomic oxygen degradation less than 1×10 -20 mg / atom, 1×10 -21 mg / atom, or 1×10 -22 mg / atom when tested according to the atomic oxygen degradation test. Such resistance to degradation by atomic oxygen is particularly useful when the light-shielding article is part of a low Earth orbit device.

[0060] The light-shielding article according to at least some embodiments of the present disclosure also desirably has a low moisture transmission rate through the article, e.g., preferably a maximum of 5×10 -3 , or a maximum of 5×10 -5 g / m 2 / day water vapor transmission rate (WVTR) at a temperature of 50°C and a relative humidity (RH) of 100%. The WVTR is approximately 5×10 -3 g / m 2When indicating the transmittance per day, it can be measured using a PERMATRAN 700 instrument manufactured by AMETEK MOCON (Brooklyn Park, MN). The WVTR is approximately 5×10 -5 g / m 2 When indicating the transmittance per day, it can be measured with an AQUATRAN 2 instrument manufactured by AMETEK MOCON.

[0061] In addition, the light-shielding article described herein may exhibit a desired level of dielectric loss and / or permittivity.

[0062] The light-shielding article according to a preferred embodiment of the present disclosure, after exposure to ultraviolet light at a certain dose (e.g., in units of joules per square centimeter (J / cm 2 )) such as the dose mentioned in the following examples, shows that the average reflectance of the wavelength from 400 nm to 700 nm passing through the article decreases by less than 20%, less than 10%, less than 5%, or less than 1%. The first multilayer optical film

[0063] Referring again to each of FIGS. 1 and 2, the light-shielding article 10 includes a first multilayer optical film 20 that includes at least a plurality of alternating first polymer optical layers 23 (A - N) and second polymer optical layers 22 (A - N), as further described below.

[0064] Typically, the first multilayer optical film has a thickness of 2.0 micrometers or more, 2.5 micrometers, 3.0 micrometers, 3.5 micrometers, 4.0 micrometers, 5.0 micrometers, or 5.5 micrometers or more, and 1000 micrometers or less, 950 micrometers, 900 micrometers, 850 micrometers, 800 micrometers, 750 micrometers, or 700 micrometers or less, for example, a thickness of 2 micrometers to 1000 micrometers.

[0065] In some cases, a plurality of alternating first and second polymeric optical layers collectively reflect at least 60, 70, 80, 90, or 95 percent of incident visible light over a reflection bandwidth that is at least 30 nanometers in wavelength within the wavelength ranges of 400 nm to 700 nm, 400 nm to 500 nm, 450 nm to 550 nm, 600 nm to 700 nm, or any combination thereof, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°.

[0066] Optionally, a plurality of alternating first and second polymeric optical layers collectively reflect at least 60, 70, 80, 90, or 95 percent of incident visible light over a reflection bandwidth that is a wavelength greater than at least 30 nanometers, e.g., at least 50 nanometers, 75 nanometers, 100 nanometers, 125 nanometers, 150 nanometers, or 175 nanometers in wavelength within the wavelength range of 400 nm to 700 nm, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°.

[0067] In some cases, a plurality of alternating first and second polymeric optical layers collectively reflect at least 70, 80, 90, or 95 percent of incident infrared light over a reflection bandwidth that is at least 30 nanometers in wavelength within the wavelength ranges of 700 nm to 1600 nm and / or 700 nm to 2000 nm, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°.

[0068] The use of multilayer reflective films containing alternating layers of two or more polymers for reflecting light is known and is described, for example, in U.S. Patent No. 3,711,176 (Alfrey, Jr. et al.), U.S. Patent No. 5,103,337 (Schrenk et al.), International Publication No. 96 / 19347 (Jonza et al.), and International Publication No. 95 / 17303 (Ouderkirk et al.). The reflection and transmission spectra of a particular multilayer film depend primarily on the optical thickness of the individual layers, which is defined as the product of the actual thickness of the layer and the refractive index. Thus, the film can be designed to reflect light at infrared, visible, or ultraviolet wavelengths λ M by selecting the appropriate optical thickness of the layers according to the following equation.

[0069] λ M =(2 / M) * D r

[0070] where M is an integer representing a particular order of the reflected light, and D r is the optical thickness of an optical repeating unit (also called a multilayer laminate) containing two or more polymer layers. Thus, D r is the sum of the optical thicknesses of the individual polymer layers that make up the optical repeating unit. D rIt is always half a wavelength (λ) thick, where λ is the wavelength of the primary reflection peak. By varying the optical thickness of the optical repeating unit along the thickness of the multilayer film, a multilayer film that reflects light over a wide range of wavelengths can be designed. This band is generally referred to as the reflection band or the blocking band. In some embodiments, the reflection band has sharp spectral edges on the long wavelength (red) side and / or the short wavelength (blue) side. It may be desirable to design a reflective film or other optical element that reflects light over a selected range within the visible region of the spectrum, for example, a reflective film that reflects only green light. In such cases, it may be desirable for the reflection band to have steep edges on both the red and blue sides. Multilayer optical films exhibiting sharp reflection band edges are described in detail, for example, in U.S. Patent No. 6,967,778 (Wheatley et al.), which is hereby incorporated by reference in its entirety.

[0071] In one embodiment, an optical polymer film or a laminated optical polymer film having first and second major surfaces is provided. The term "film" is used to refer to a planar form of plastic that is thick enough to be self-supporting but thin enough to be bent, folded, conformed, or creased without cracking. The film thickness varies depending on the desired application and manufacturing method.

[0072] The term "optical film" is used herein to refer to any reflective or partially reflective polymeric film designed to exhibit a desired reflection, transmission, absorption, or refraction of light when exposed to wavelengths in a particular band of electromagnetic energy. Thus, conventional normally transmissive polymeric films such as polyester and polypropylene are not considered "optical films" for the purposes of this disclosure, even if such films may exhibit some degree of reflectivity or glare when viewed at an angle. Films that exhibit both reflective and transmissive properties are considered to be within the scope of this disclosure, even if they are, for example, partially transmissive. Preferred optical polymeric films generally absorb less than 25 percent of the radiant energy impinging on the film surface. Preferably, the absorbed radiant energy is less than 10 percent, and most preferably less than 5 percent. The radiant energy is typically represented as energy within a wavelength range and can be reflected either specularly or diffusely. The reflectivity may be isotropic, i.e., the film may have the same reflective properties along both in-plane axes, or anisotropic, i.e., the film may have different reflective properties along orthogonal in-plane axes. The difference in reflective properties along the in-plane axes can be varied by controlling the relationship between the refractive indices along each axis for each of the constituent materials.

[0073] Optical films are provided in various forms and are selected according to the desired application. Some suitable examples include multilayer polarizers, visible and infrared mirrors, and color films such as those described in International Publication Nos. WO 95 / 17303, WO 96 / 19347, and WO 97 / 01440, U.S. Patent Nos. 6,045,894 (Jonza et al.), 6,531,230 (Weber et al.), 5,103,337 (Schrenk et al.), 5,122,905 (Wheatley et al.), 5,122,906 (Wheatley), 5,126,880 (Wheatley et al.), 5,217,794 (Schrenk), 5,233,465 (Schrenk et al.), 5,262,894 (Wheatley et al.), 5,278,694 (Wheatley et al.), 5,339,198 (Wheatley et al.), 5,360,659 (Arends et al.), 5,448,404 (Schrenk et al.), 5,486,949 (Schrenk et al.), 4,162,343 (Wilcox et al.), 5,089,318 (Shetty et al.), 5,154,765 (Armanini), 3,711,176 (Alfrey, Jr. et al.), and Reissued U.S. Patent Nos. 31,780 (Cooper et al.), 34,605 (Schrenk et al.). The entire contents of all of these are incorporated herein by reference.

[0074] Examples of optical films containing immiscible blends of two or more polymer materials include blend mirrors and polarizers described in International Publication No. WO 97 / 32224 (Ouderkirk et al.), U.S. Patent No. 6,179,948 (Merrill et al.), and U.S. Patent No. 5,751,388 (Larson), the entire contents of which are incorporated herein by reference. Reflection and transmission characteristics are obtained from the presence of discontinuous polymer regions having a diameter in a cross-section perpendicular to the major axis that is only a small part of the distance corresponding to the wavelength of light, and desired optical characteristics can also be obtained by orientation. Further suitable reflective films include reflective cube corner sheets described in U.S. Patent Nos. 5,450,235 (Smith et al.), 5,691,846 (Benson et al.), 5,614,286 (Bacon et al.), and 5,763,049 (Frey et al.), the disclosures of which are all incorporated herein by reference. Examples of these films are commercially available and can be obtained, for example, from 3M Company as "3M SCOTCHLITE Reflective Material Series 6200 High Gloss Film" and "SCOTCHLITE Diamond Grade Ultraflexible Conspicuity Sheeting Series 960". These optical films achieve optical characteristics through the presence of a cured cube corner structure on one side of the polymer film structure.

[0075] Optionally, the microvoid film may be employed as an optical film. "Microvoids" means having discrete internal voids with an average void diameter of 50 to 10,000 nm, and these voids may be spherical, oblate, or some other shape. Exemplary polymers useful for forming microvoid polymer films include polyethylene terephthalate (PET) available from 3M Company. Modified PET copolyesters including PETG available as SPECTAR 14471 and EASTAR GN071 from Eastman Chemical Company (Kingsport, TN), and PCTG available as TIGLAZE ST and EB0062 from Eastman Chemical Company, for example, are also useful high refractive index polymers. The molecular orientation of PET and PET modified copolyesters can be increased by stretching, thereby increasing the in-plane refractive index and resulting in higher reflectivity in multilayer optical films. Generally, in order to nucleate voids during the stretching process, during extrusion prior to stretching, an incompatible polymer additive or inorganic particle additive is blended into the PET host polymer at a level of at least 10 wt%, at least 20 wt%, at least 30 wt%, at least 40 wt%, or even at least 49 wt%. Exemplary incompatible polymer additives suitable for PET include fluoropolymers, polypropylene, polyethylene, and other polymers that do not adhere well to PET. Similarly, when polypropylene is the host polymer, in order to nucleate voids during the stretching process, an incompatible polymer additive such as PET or a fluoropolymer can be added to the polypropylene host polymer at a level of at least 10 wt%, at least 20 wt%, at least 30 wt%, at least 40 wt%, or even at least 49 wt% during extrusion prior to stretching. Exemplary suitable inorganic particle additives for nucleating voids in microvoid polymer films include titania, silicon oxide, aluminum oxide, aluminum silicate, zirconia, calcium carbonate, barium sulfate, and glass beads and hollow glass bubbles, although other inorganic particles and combinations of inorganic particles may also be used.Crosslinked polymer microspheres can also be used in place of the inorganic particles. Preferably, the polymer particles include aromatic polyester particles. The inorganic particles can be added to the host polymer at a level of at least 10 wt%, at least 20 wt%, at least 30 wt%, at least 40 wt%, or even at least 49 wt% during extrusion prior to stretching to nucleate voids during the stretching process. The inorganic particles, if present, preferably have a volume average particle size of 5 nm to 1 micrometer, although other particle sizes may also be used.

[0076] In some embodiments, the polymer optical layer of the first multilayer optical film includes a fluoropolymer, polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polypropylene (PP) copolymer, polyethylene (PE) copolymer, copolymer of ethyl acrylate and methyl methacrylate (CoPMMA), blend of PMMA and polyvinylidene fluoride (PVDF), acrylate copolymer, polyurethane, polyethylene naphthalate (PEN), or combinations thereof.

[0077] When the first multilayer optical film includes a fluoropolymer, the polymer optical layer preferably includes a fluoropolymer independently selected from the group consisting of a copolymer of tetrafluoroethylene (TFE), hexafluoropropylene (HFP), and vinylidene fluoride; a copolymer of TFE, HFP, vinylidene fluoride, and perfluoropropyl vinyl ether (PPVE); polyvinylidene fluoride (PVDF); ethylene chlorotrifluoroethylene (ECTFE) polymer; ethylene tetrafluoroethylene (ETFE); perfluoroalkoxy alkane (PFA) polymer; fluorinated ethylene propylene (FEP) polymer; polytetrafluoroethylene (PTFE); a copolymer of TFE, HFP, and ethylene: polyvinyl fluoride (PVF); and combinations thereof.

[0078] Referring back to each of FIGS. 1 and 2, the first multilayer optical film 20 includes a multilayer optical laminate having alternating layers 22, 23 typically made of at least two materials including different polymers. The in-plane refractive index n1 in one in-plane direction of the high refractive index layer 23 is higher than the in-plane refractive index n2 of the low refractive index layer 22 in the same in-plane direction. The difference in refractive index at each boundary between the layer 22 and the layer 23 reflects a part of the incident light. The transmission characteristics and reflection characteristics of the first multilayer optical film 20 are based on the coherent interference of light caused by the refractive index difference between the layer 22 and the layer 23 and the thicknesses of the layer 22 and the layer 23. When the effective refractive index (or the in-plane refractive index at normal incidence) is different between the layer 22 and the layer 23, the interface between the adjacent layer 22 and the layer 23 forms a reflecting surface. The reflectivity of the reflecting surface depends on the square of the difference between the effective refractive index of the layer 22 and the effective refractive index of the layer 23 (for example, (n1 - n2) 2 ). By increasing the refractive index difference between the layer 22 and the layer 23, it is possible to achieve an improvement in refractive power (higher reflectivity), a thinner film (thinner layers or fewer layers), and wider bandwidth performance. The refractive index difference in one in-plane direction in an exemplary embodiment is at least about 0.05, preferably more than about 0.10, more preferably more than about 0.15, and even more preferably more than about 0.20.

[0079] In some embodiments, the materials of the layer 22 and the layer 23 have essentially different refractive indices. In another embodiment, at least one of the materials of the layer 22 and the layer 23 has stress-induced birefringence characteristics, whereby the refractive index (n) of the material is affected by the stretching process. By stretching the first multilayer optical film 20 over a range from uniaxial orientation to biaxial orientation, a film having a specific range of reflectivities for plane-polarized incident light in different directions can be produced.

[0080] The number of layers of the first multilayer optical film 20 is selected to achieve the desired optical properties using the minimum number of layers for reasons of film thickness, flexibility, and economy. In the case of a reflective film such as a mirror, 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 150 or 200. In other embodiments, the number of layers is at least 250.

[0081] The first multilayer optical film includes a plurality of pairs of low / high refractive index film layers, and each pair of low / high refractive index layers 22, 23 has a total optical thickness that is one-half of the center wavelength of the band designed to reflect. Such a stack of films is generally referred to as a quarter-wave stack. In some embodiments, different pairs of low / high refractive index layers may have different total optical thicknesses, such as when a broadband reflective optical film is desired.

[0082] Regardless of whether the various constituent layers of the first multilayer optical film are skin layers or optical layers, they can be resistant to ultraviolet radiation. Many fluoropolymers are resistant to UV radiation. Examples of fluoropolymers that can be used include copolymers of tetrafluoroethylene (TFE), hexafluoropropylene (HFP), and vinylidene fluoride (e.g., available from 3M Company under the trade name 3M DYNEON THV); copolymers of TFE, HFP, vinylidene fluoride, and perfluoropropyl vinyl ether (PPVE) (e.g., available from 3M Company under the trade name 3M DYNEON THVP); polyvinylidene fluoride (PVDF) (e.g., 3M DYNEON PVDF 6008 manufactured by 3M Company); ethylene chlorotrifluoroethylene polymer (ECTFE) (e.g., available from Solvay (Brussels, Belgium) as HALAR 350LC ECTFE); ethylene tetrafluoroethylene copolymer (ETFE) (e.g., available from 3M Company as 3M DYNEON ETFE 6235); perfluoroalkoxy alkane polymer (PFA); fluorinated ethylene propylene copolymer (FEP); polytetrafluoroethylene (PTFE); copolymers of TFE, HFP, and ethylene (HTE) (e.g., available from 3M Company as 3M DYNEON HTE1705). Combinations of fluoropolymers can also be used. In some embodiments, the fluoropolymer includes FEP. In some embodiments, the fluoropolymer includes PFA. In some embodiments, the fluoropolymer includes PVF.

[0083] Examples of non-fluorinated polymers that can be used in at least one layer of the first multilayer optical film include PET, polypropylene copolymers, polyethylene copolymers, polyethylene methacrylate copolymers, polymethyl methacrylate, methyl methacrylate copolymers (e.g., copolymers of ethyl acrylate and methyl methacrylate), polyurethanes, acrylate copolymers, extended chain polyethylene polymers (ECPE), polyethylene naphthalate (PEN), or at least one of combinations thereof. Generally, combinations of non-fluorinated polymers can be used. Exemplary non-fluorinated polymers for use in particularly high refractive index optical layers include homopolymers of polymethyl methacrylate (PMMA), such as those available as CP71 and CP80 from Ineos Acrylics, Inc. (Wilmington, DE), and polyethyl methacrylate (PEMA) having a glass transition temperature lower than PMMA. A suitable polyethylene naphthalate (PEN) polymer is available from DuPont Teijin (Chester, VA) under the trade name "Teonex Q51". Further useful polymers include copolymers of methyl methacrylate, such as those available as PERSPEX CP63 from Ineos Acrylics, Inc. or as ALTUGLAS 510 from Arkema (Philadelphia, PA), for example, copolymers made from 75 wt% methyl methacrylate and 25 wt% ethyl acrylate, copolymers of methyl methacrylate monomer units and n-butyl methacrylate monomer units, etc. A blend of PMMA and PVDF may also be used.

[0084] Suitable triblock acrylic copolymers are available, for example, from Kuraray America Inc. (Houston, TX) as KURARITY LA4285. Further suitable polymers for the optical layer, especially for use in the refractive index optical layer, may include at least one of polyolefin copolymers such as poly(ethylene-co-octene) (available, for example, from Dow Elastomers (Midland, MI) as ENGAGE 8200), polyethylene methacrylate (available, for example, from Dow Elastomers as ELVALOY), poly(propylene-co-ethylene) (available, for example, from Atofina Petrochemicals, Inc. (Houston, TX) as Z9470); and copolymers of atactic polypropylene and isotactic polypropylene. The materials may be selected based on the light absorption or transmission characteristics and refractive index described herein. Generally, the greater the refractive index between two materials, the thinner the film can be, which may be desirable for efficient heat transfer.

[0085] The multilayer optical film can be made, for example, by coextruding alternating polymer layers having different refractive indices as described in 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.), 7,632,568 (Padiyath et al.), 7,652,736 (Padiyath et al.), and 7,952,805 (McGurran et al.), and International Publications Nos. 95 / 17303 (Ouderkirk et al.) and 99 / 39224 (Ouderkirk et al.).

[0086] Typically, the first multilayer optical film has an average thickness of 50 micrometers to 250 micrometers, for example, 50 micrometers or more, 55 micrometers, 60 micrometers, 65 micrometers, 70 micrometers, 75 micrometers, 80 micrometers, 85 micrometers, 90 micrometers, or 95 micrometers or more, and 250 micrometers or less, 225 micrometers, 200 micrometers, 175 micrometers, 150 micrometers, 125 micrometers, 100 micrometers, 90 micrometers, 80 micrometers, 70 micrometers, or 60 micrometers or less. The second multilayer optical film

[0087] Referring again to FIG. 1, the light-shielding article 10 includes a second multilayer optical film 30 that includes at least a plurality of alternating first inorganic optical layers 33(A to N) and second inorganic optical layers 32(A to N), as further described below.

[0088] Typically, the second multilayer optical film has a thickness of 200 nm or more, 250 nm, 300 nm, 350 nm, 400 nm, 500 nm, or 550 nm or more, and 900 nm or less, 850 nm, 800 nm, 750 nm, 700 nm, 650 nm, or 600 nm or less, for example, a thickness of 200 nm to 900 nm.

[0089] In some cases, the plurality of alternating first and second inorganic optical layers collectively reflect and absorb at least 60, 70, 80, 90, or 95 percent, on average, of incident ultraviolet light over a reflection bandwidth of at least 30 nanometers at a wavelength within the wavelength ranges of 190 nm to 240 nm, 240 nm to 300 nm, 300 nm to 350 nm, 350 nm to 400 nm, or any combination thereof, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°.

[0090] Optionally, the plurality of alternating first and second inorganic optical layers collectively reflect and absorb at least 60, 70, 80, 90, or 95 percent of the incident ultraviolet light over a reflection bandwidth that is greater than at least 30 nanometers at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, for example, a reflection bandwidth that is a wavelength within the wavelength range of 190 nm to 400 nm, such as at least 50 nanometers, 75 nanometers, 100 nanometers, 125 nanometers, 150 nanometers, or 175 nanometers.

[0091] Because the plurality of alternating first and second inorganic optical layers collectively reflect and absorb, a portion of the incident ultraviolet light can be absorbed and a portion can be reflected. In some cases, the alternating first and second inorganic optical layers collectively absorb at least 30, 40, 50, 60, 70, 80, 90, or 95 percent of the incident light over a wavelength bandwidth of at least 30 nanometers within the wavelength range of 190 nm to less than 350 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°. In some cases, the alternating first and second inorganic optical layers collectively reflect at least 30, 40, 50, 60, 70, 80, 90, or 95 percent of the incident light over a wavelength bandwidth of at least 30 nanometers within the wavelength range of greater than 400 nm to less than 700 nm, less than 190 nm to 400 nm, 190 nm to 240 nm, 240 nm to 300 nm, 300 nm to 350 nm, 350 nm to less than 400 nm, or any combination thereof at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°. In a selected embodiment of the light-shielding article, the alternating first and second inorganic optical layers collectively transmit at least 50, 60, 70, 80, 90, or 95 percent of the incident visible light within the wavelength range of greater than 400 nm to 700 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°. Inorganic layer

[0092] In some cases, the first optical layer comprises at least one of niobium oxide, titanium oxide, silicon oxynitride, molybdenum oxide, tungsten oxide, silicon nitride, indium tin oxide, hafnium oxide, tantalum oxide, zirconium oxynitride, zirconium oxide, aluminum zinc oxide, or zinc oxide. As is known to those skilled in the art, an alloy of oxides may be suitable. In some cases, the second optical layer comprises at least one of silicon oxide, aluminum oxide, aluminum fluoride, magnesium fluoride, calcium fluoride, indium tin oxide, or zinc oxide. In a selected embodiment, the first optical layer comprises at least one of niobium oxide or titanium oxide, and the second optical layer comprises silicon oxide. When employing a photoactive inorganic material such as titanium oxide, typically, in order to minimize the degradation of the organic layer, a non-photoactive material (e.g., silicon oxide, aluminum oxide, etc.) may be disposed between the photoactive inorganic material and any organic layer. For example, referring again to FIG. 1, the layer of non-photoactive material may be an intermediate layer (not shown) disposed between the first optical layer 33N and the first major surface 21 of the first multilayer optical film 20.

[0093] Multilayer optical films are particularly suitable for the design of optical thin film laminates consisting of alternating thin layers of inorganic dielectric materials having a refractive index contrast. For several decades, these have been used in application examples in the UV spectral region, visible spectral region, NIR spectral region, and IR spectral region. Depending on the spectral region of interest, there are specific materials suitable for that region. Also, in order to coat these materials, one of two forms of physical vapor deposition (PVD), namely evaporation or sputtering, is used. Evaporation coating depends on heating the coating material (evaporant) to the evaporation temperature. Subsequently, the vapor condenses on the substrate. Regarding evaporation dielectric mirror coatings, an electron beam evaporation process is most commonly used. Sputtering coating uses high-energy gas ions to collide with the surface of the material ("target") to release atoms, and then condenses those atoms onto a nearby substrate. Depending on which coating method is used and the settings used for that method, the coating rate of the thin film coating and the relationship between the structure and properties will be strongly affected. Ideally, the coating rate should be fast enough to enable an acceptable process throughput and film performance characterized by a high-density, low-stress, void-free, non-optically absorbing coating layer. Those skilled in the art can also extend such deposition techniques to include CVD, ALD, and other depositions.

[0094] 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 economy. Typically, the total number of layers is preferably 21 or less, 19, 17, 15, or 13 or less optical layers, and 3 or more optical layers, 5, 7, 9, or 11 or more optical layers may be required.

[0095] The thickness of each of the first and second optical layers can vary substantially. For example, in some cases, each of the first optical layer and each of the second optical layer are independently 5 nm or more, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, or 70 nm or more in thickness, and 200 nm or less, 150 nm, 145 nm, 140 nm, 135 nm, 130 nm, 125 nm, 120 nm, 115 nm, 110 nm, 105 nm, 100 nm, 95 nm, 90 nm, 85 nm, 80 nm, or 75 nm or less in thickness.

[0096] The multilayer optical films described herein can be made using common processing techniques, such as those described in U.S. Patent No. 6,783,349 (Neavin et al.), the entire disclosure of which is incorporated herein by reference in its entirety.

[0097] Dielectric mirrors having an optical thin film laminate design consisting of alternating thin layers of inorganic dielectric materials having a refractive index contrast have been used for applications in the UV spectral region, visible spectral region, NIR spectral region, and IR spectral region for several decades. Depending on the spectral region of interest, 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 coating relies on heating the coating material (the evaporant) to its evaporation temperature. Subsequently, the vapor condenses on the substrate. For evaporation dielectric mirror coatings, an electron beam evaporation process is most commonly used.

[0098] Sputtering coating uses high-energy gas ions, collides them with the surface of a material ("target") to release atoms, and then condenses those atoms onto a nearby substrate. Depending on which coating method is used and the settings used for that method, the coating speed of the thin film coating and the relationship between the structure and properties will be strongly affected. Ideally, the coating speed should be fast enough to enable an acceptable process throughput and film performance characterized by a high-density, low-stress, void-free, non-optically absorbing coating layer.

[0099] For the production of inorganic coatings, an electron beam process is optimal for coating individual parts. Optionally, light-shielding articles can be prepared in a continuous roll-to-roll (R2R) manner for larger articles. In some chambers, R2R film coating was assumed, but a one-by-one coating sequence is still required. For the R2R sputtering of the inorganic layer of the light-shielding article 10, it is advantageous to use a sputtering system in which a plurality of sources are arranged around one or optionally two coating drums. In this case, for a 13-layer optical laminate design, it can be realized by a two-pass machine process or a single-pass machine process in which a high refractive index layer and a low refractive index layer are alternately coated sequentially. The number of machine passes required will depend on factors such as the machine design, cost, and practicality of 13 consecutive sources. Furthermore, it is necessary to match the coating speed to a single film line speed.

[0100] The conveyance of the film roll initially starts at a predetermined speed and, after the output of the sputtering source has risen to the maximum operating output, a reactive gas is introduced and then a steady state is reached. Depending on the length of the film to be coated, this process continues until the full length is reached. In this case, the sputtering source is orthogonal to the film being coated and wider than that film, so the coating thickness uniformity is very high. When the coated film has reached the desired length, the reactive gas is set to zero and the target is sputtered to a pure metal surface state. Next, the direction of the film is reversed and AC frequency (40 kHz) power is applied to the rotary pair of sputtering targets in an argon sputtering atmosphere. When a steady state is reached, a reactive gas of oxygen is introduced to provide permeability and a low refractive index. At a predetermined process setting and line speed, the second layer is coated over the length where layer 1 was coated. Also in this case, these sputtering sources are orthogonal to the film being coated and wider than that film, so the coating thickness uniformity is very high. After the coated film has reached the desired length, the reactive oxygen is removed and the target is sputtered to a pure metal surface state in argon. Depending on the target of the optical target, the third to fifth layers (or the seventh or ninth layer, or the eleventh or thirteenth layer, etc.) are coated in this order. Optionally, some layers are deposited in multiple machine passes, for example to limit the heat load. When completed, the film roll is removed for post-treatment.

[0101] The examples will more specifically describe an exemplary process for fabricating an exemplary light-shielding article 10. Barrier coating

[0102] Referring to FIG. 2, the barrier coating 50 includes at least one diode 53 disposed on the first multilayer optical film 20, as further described below. Preferably, the barrier coating includes a plurality of diodes 53, and optionally, the plurality of diodes 53 are at least or exactly two diodes, three diodes, four diodes, five diodes, or six diodes.

[0103] The barrier coatings of at least some embodiments of the present disclosure can exhibit excellent mechanical properties such as elasticity and flexibility, yet still have a low atomic oxygen degradation rate. The coating has at least one diode including a (co)polymer layer and an oxide layer, and can have additional inorganic layers or organic / inorganic hybrid layers. In one embodiment, the barrier coating can have alternating (co)polymer layers and oxide layers. In other exemplary embodiments, the barrier coatings of the present disclosure can include one or more organic / inorganic hybrid layers.

[0104] Each (co)polymer layer within at least one diode and the outer (co)polymer layer includes a (co)polymer selected from an olefin (co)polymer, a (meth)acrylate (co)polymer, a urethane (co)polymer, a fluoropolymer, a silicone (co)polymer, or a combination thereof.

[0105] The (co)polymer layer can be formed from various organic materials or compounds using various processes. The (co)polymer layer may be crosslinked in situ after application. In one embodiment, the (co)polymer layer can be formed by flash evaporation, deposition, and (co)polymerization of monomers using, for example, heat, plasma, UV radiation, or an electron beam.

[0106] Exemplary monomers for use in such a method include volatile (meth)acrylate monomers. In a particular embodiment, volatile acrylate monomers are employed. Suitable (meth)acrylates have a molecular weight low enough to allow flash evaporation and high enough to allow condensation on the substrate. The organic material or compound can also be evaporated using any method for evaporating metal alkoxides, such as those described below.

[0107] If desired, the (co)polymer layer can alternatively be applied using conventional methods such as plasma deposition, solution coating, extrusion coating, roll coating (e.g., gravure roll coating), or spray coating (e.g., electrostatic spray coating), and if desired, can be crosslinked or (co)polymerized (e.g., as described above). The desired chemical composition and thickness of the additional layer will depend to some extent on the nature of the light-shielding article and the desired purpose. The coating efficiency can be improved by cooling the light-shielding article.

[0108] Exemplary organic compounds include esters, vinyl compounds, alcohols, carboxylic acids, acid anhydrides, acyl halides, thiols, amines, and mixtures thereof. Non-limiting examples of esters include (meth)acrylates that can be used alone or in combination with other polyfunctional or monofunctional (meth)acrylates. Exemplary (meth)acrylates include hexanediol diacrylate, ethoxyethyl acrylate, phenoxyethyl acrylate, cyanoethyl (mono)acrylate, isobornyl acrylate, octadecyl acrylate, isodecyl acrylate, lauryl acrylate, beta-carboxyethyl acrylate, tetrahydrofurfuryl acrylate, dinitrile acrylate, pentafluorophenyl acrylate, nitrophenyl acrylate, 2-phenoxyethyl acrylate, 2,2,2-trifluoromethyl acrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate, tetraethylene glycol diacrylate, neopentyl glycol diacrylate, propoxylated neopentyl glycol diacrylate, polyethylene glycol diacrylate, tetraethylene glycol diacrylate, bisphenol A epoxy diacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propylated trimethylolpropane triacrylate, tris(2-hydroxyethyl)-isocyanurate triacrylate, pentaerythritol triacrylate, phenylthioethyl acrylate, naphthyloxyethyl acrylate, IRR-214 cyclic diacrylate manufactured by UCB Chemicals, epoxy acrylate RDX80095 manufactured by Rad-Cure Corporation, the corresponding methacrylates of the acrylates listed above, and mixtures thereof. Exemplary vinyl compounds include vinyl ethers, styrene, vinyl naphthalene, and acrylonitrile. Exemplary alcohols include hexanediol, naphthalene diol, and hydroxyethyl methacrylate.Exemplary carboxylic acids include phthalic acid and terephthalic acid, (meth)acrylic acid). Exemplary acid anhydrides include phthalic anhydride and glutaric anhydride. Exemplary acyl halides include hexanedioyl dichloride and succinyl dichloride. Exemplary thiols include ethylene glycol-bisthioglycolate and phenylthioethyl acrylate. Exemplary amines include ethylenediamine and hexane 1,6-diamine.

[0109] Optionally, at least one (co)polymer layer or outer (co)polymer layer within at least one diad further comprises an ultraviolet absorber, a hindered amine light stabilizer, an antioxidant, or a combination thereof. UV absorbers (UVA), hindered amine light stabilizers (HALS), and antioxidants can help prevent photooxidative degradation of the (co)polymer layer. Suitable compounds include benzophenone, benzotriazole, and triazine (e.g., benzotriazine). Exemplary UVA available for incorporation into the (co)polymer layer include those available under the trade names "TINUVIN 1577" and "TINUVIN 1600" from BASF Corporation (Florham Park, NJ). U.S. Patent No. 9,670,300 (Olson et al.) and U.S. Patent Application Publication No. 2017 / 0198129 (Olson et al.) describe exemplary UVA oligomers that are compatible with PVDF fluoropolymers. Exemplary HALS available for incorporation into the hard coat layer include those available under the trade names "CHIMMASORB 944" and "TINUVIN 123" from BASF Corporation. Typically, the UVA, HAL, and / or antioxidant is incorporated into the (co)polymer layer at a concentration of 1 to 10 wt%.

[0110] Each of the inorganic layer within at least one diode and any optional at least one outer inorganic layer 58 overlapping the outer (co)polymer layer contains an inorganic material selected from silicon oxide, silica alumina oxide, silicon oxynitride, gallium oxide, magnesium oxide, niobium oxide, titanium dioxide, yttrium oxide, zinc oxide, tin oxide, nickel oxide, tungsten oxide, aluminum-doped zinc oxide, indium tin oxide, zirconium oxide, zirconium oxynitride, hafnia, aluminum oxide, alumina-doped silicon oxide, lanthanum fluoride, neodymium fluoride, aluminum fluoride, magnesium fluoride, calcium fluoride, or a combination thereof.

[0111] The outer (co)polymer layer 56 overlaps at least one diode 53, and the at least one diode 53 may be a plurality of diodes 53 as described above. The outer (co)polymer layer 56 is preferably crosslinked.

[0112] In some embodiments, the outer (co)polymer layer comprises an olefin (co)polymer selected from low density polyethylene, linear low density polyethylene, ethylene vinyl acetate, polyethylene methyl acrylate, polyethylene octene, polyethylene propylene, polyethylene butene, polyethylene maleic anhydride, polymethylpentene, polyisobutene, polyisobutylene, polyethylene propylene diene, cyclic olefin (co)polymer, and blends thereof.

[0113] In an exemplary embodiment, at least one (co)polymer layer or the outer (co)polymer layer within at least one diode further comprises an ultraviolet absorber, a hindered amine light stabilizer, an antioxidant, or a combination thereof.

[0114] The ultraviolet absorber is preferably selected from benzotriazole compounds, benzophenone compounds, triazine compounds, or combinations thereof. Currently preferred hindered amine light stabilizers are available under the trade name "TINUVIN" from BASF U.S.A (Florham Park, NJ). The hindered amine light stabilizer is preferably selected from TINUVIN 123, TINUVIN 144, TINUVIN 292, or combinations thereof. Currently preferred antioxidants are available from BASF under the trade names "IRGANOX" and "IRGAFOS". Antioxidants suitable for polyolefins are preferably selected from IRGANOX 1010, IRGANOX 1076, IRGAFOS 168, or combinations thereof.

[0115] The barrier coating can be subjected to various post-treatments such as heat treatment, UV or vacuum UV (VUV) treatment, or plasma treatment. Heat treatment can be carried out by passing the barrier coating through an oven or directly heating the barrier coating within the coating apparatus (for example, using an infrared heater or directly heating on a drum). Heat treatment can be carried out at a temperature of, for example, about 30°C to about 200°C, about 35°C to about 150°C, or about 40°C to about 70°C. Substrate

[0116] As described above, the substrate is an optional component in the light-shielding article according to the present disclosure. In some cases, a polymer substrate can be used. The advantage of employing a polymer substrate is that it can avoid the high cost when using glass that is rigid and / or has a small surface area. In addition, in some embodiments according to the present disclosure, a flexible substrate is used in a roll-to-roll process for manufacturing the light-shielding article. In some cases, the substrate (or the light-shielding article) has an area of at least 50 square centimeters, for example, at least 60, 70, 80, 90, or at least 100 square centimeters.

[0117] In any of the foregoing embodiments, the substrate 14 may be comprised of or consist of a polymeric material such as a (co)polymer. In some exemplary embodiments, the substrate comprises a fluoropolymer (co)polymer containing polymerization units derived from one or more monomers selected from polyethylene terephthalate (PET), crosslinked polysiloxane, silicone thermoplastic polymer, crosslinked urethane, thermoplastic urethane, crosslinked (meth)acrylate, PMMA, coPMMA, polyimide, cyclic olefin copolymer, cyclic olefin polymer, polycarbonate, PEN, or tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, perfluoroalkoxy alkylene, vinyl fluoride, or combinations thereof.

[0118] Suitable polyimide substrates are available under the trade name "KAPTON" from E.I.DuPont de Nemours (Wilmington, DE), among which "KAPTON CS100" is currently preferred. Suitable PMMA polymers include those available as CP71 and CP80 from Ineos Acrylics, Inc. (Wilmington, DE). One suitable polycarbonate substrate is available under the trade name "Makrofol" from Bayer AG (Darmstadt, Germany). Suitable methyl methacrylate copolymers (CoPMMA) include, for example, CoPMMA made from 75 wt% methyl methacrylate (MMA) monomer and 25 wt% ethyl acrylate (EA) monomer (e.g., available under the trade name "PERSPEX CP63" from Ineos Acrylics, Inc. (London, England) or under the trade name "ATOGLAS 510" from Arkema Corp. (Philadelphia, PA)), CoPMMA formed from MMA comonomer units and n-butyl methacrylate (nBMA) comonomer units, or a blend of PMMA and poly(vinylidene fluoride) (PVDF). Suitable polyethylene naphthalate (PEN) polymers are available under the trade name "Teonex Q51" from DuPont Teijin (Chester, VA).

[0119] In one exemplary embodiment, the fluorinated (co)polymer preferably comprises tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, perfluoroalkoxy alkane, or combinations thereof. Suitable fluoropolymer substrates are available under the trade name "TEFLON FEP100" from E.I.DuPont de Nemours (Wilmington, DE), or its "TEFLON FEP100 500A" is currently preferred. Suitable exemplary fluoropolymers also include the copolymers of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride (THV) under the trade names "DYNEON THV 220", "DYNEON THV 221", "DYNEON THV 230", "DYNEON THV 2030", "DYNEON THV 415", "DYNEON THV 500", "DYNEON THV 610", and "DYNEON THV 815" manufactured by Dyneon LLC (Oakdale, MN).

[0120] The smoothness and adhesion of the layer to the substrate can be improved by optional appropriate pretreatment of the substrate or optional application of a primer layer. Methods of surface modification are known in the art. In one embodiment, the pretreatment method involves pre-discharge treatment of the substrate (e.g., plasma, glow discharge, corona discharge, dielectric barrier discharge, or atmospheric pressure discharge) in the presence of a reactive or non-reactive atmosphere, chemical pretreatment, or flame pretreatment. These pretreatments can help ensure that the surface of the substrate is receptive to the subsequently applied layer. In one embodiment, this method can include plasma pretreatment. In the case of an organic surface, the plasma pretreatment can include nitrogen or water vapor. Another pretreatment method involves coating the substrate with an inorganic or organic basecoat layer and then optionally further pretreating using plasma or one of the other pretreatments described above.

[0121] Preferably, the substrate transmits on average at least 70, 80, 90, or 95 percent of the incident visible light in the wavelength range of greater than 400 nm to 700 nm. Optional permeable adhesive bonding layer

[0122] Suitable permeable adhesives for one or more bonding layers (e.g., intermediate layer 12 and / or adhesive 16) include, for example, pressure-sensitive adhesives. Suitable classes of pressure-sensitive adhesives include acrylics, pressure-sensitive rubbers, pressure-sensitive synthetic rubbers, ethylene vinyl acetate, and silicones. Suitable acrylic adhesives are disclosed, for example, in U.S. Patent Nos. 3,239,478 (Harlan), 3,935,338 (Robertson), 5,169,727 (Boardman), 4,952,650 (Young et al.), 4,181,752 (Martens et al.), and are incorporated herein by reference.

[0123] In the selected embodiments, the pressure-sensitive adhesive is optically transparent, which means that the adhesive has both permeability and transparency (e.g., low haze). In certain embodiments, the optically transparent adhesive (OCA) is selected from acrylates, polyurethanes, polyolefins (such as polyisobutylene (PIB)), silicones, or combinations thereof. Exemplary OCAs include those described in International Publication No. WO 2008 / 128073 (Everaerts et al.) regarding antistatic optically transparent pressure-sensitive adhesives, U.S. Patent Application Publication No. 2009 / 089137 (Sherman et al.) regarding peelable OCA, U.S. Patent Application Publication No. 2009 / 0087629 (Everaerts et al.) regarding indium tin oxide compatible OCA, U.S. Patent Application Publication No. 2010 / 0028564 (Cheng et al.) regarding antistatic optical structures having an optically transmissive adhesive, U.S. Patent Application Publication No. 2010 / 0040842 (Everaerts et al.) regarding adhesives compatible with corrosion-sensitive layers, U.S. Patent Application Publication No. 2011 / 0126968 (Dolezal et al.) regarding optically transparent stretch-release adhesive tapes, and U.S. Patent No. 8,557,378 (Yamanaka et al.) regarding stretch-release adhesive tapes. Suitable OCAs include acrylic-based optically transparent pressure-sensitive adhesives such as 3M OCA 8146, 8211, 8212, 8213, 8214, and 8215, each available from 3M Company (St. Paul, MN), for example.

[0124] In some embodiments, the transparent adhesive may be resistant to UV damage. Exemplary adhesives that are typically resistant to UV damage include, for example, silicone adhesives and acrylic adhesives containing UV stabilizer / blocker additives. U.S. Patent No. 5,504,134 (Palmer et al.) describes, for example, the reduction of polymer substrate degradation caused by UV radiation through the use of metal oxide particles in a size range of about 0.001 to about 0.2 micrometers (in some embodiments, about 0.01 micrometers to about 0.15 micrometers). U.S. Patent No. 5,876,688 (Laundon) describes a method for producing micronized zinc oxide that is small enough to be transparent when incorporated as a UV blocker and / or scatterer into paints, coatings, finishes, plastic articles, and cosmetic materials that are suitable for use in the present invention. These fine particles, such as zinc oxide and titanium oxide, having a particle size in the range of 10 nm to 100 nm that can attenuate UV radiation, are available, for example, from Kobo Products, Inc. (South Plainfield, NJ). Electromagnetic Receiver and Electromagnetic Emitter

[0125] In a third aspect, an electromagnetic receiver and / or emitter is provided. The electromagnetic receiver and / or emitter includes a light-shielding article according to any of the embodiments of the first and second aspects described in detail above.

[0126] Some examples of electromagnetic receivers, electromagnetic emitters (and both receivers and emitters) include, for example, but are not limited to, satellites, CubeSats, nanosatellites, microsatellites, minisatellites, small satellites, medium satellites, intermediate satellites, large satellites, heavy satellites, extra heavy satellites, telescopes, antennas, antenna arrays, photosensors, drones, spacecraft, and space habitats.

[0127] Accordingly, the light-shielding article according to the present disclosure can be used to protect one or more of such electromagnetic receivers and / or emitters by being applied to a main surface (e.g., an outer surface exposed to a high-altitude environment). The light-shielding article shields at least a portion of the incident wavelengths in the visible and ultraviolet ranges while allowing transmission of wavelengths in at least a portion of the radio frequency range.

[0128] Referring again to FIG. 1, the present disclosure describes an electromagnetic receiver and / or emitter 40 including a light-shielding article 10 attached to at least a portion 42 of the electromagnetic receiver and / or emitter. The light-shielding article 10 includes a first multilayer optical film 20 and a second multilayer optical film 30 disposed on a first main surface 21 of the first multilayer optical film 20.

[0129] Referring again to FIG. 2, the present disclosure describes an electromagnetic receiver and / or emitter 40 including a light-shielding article 10 attached to at least a portion 42 of the electromagnetic receiver and / or emitter. The light-shielding article 10 includes a first multilayer optical film 20, a barrier coating 50 disposed on the first main surface 21 of the first multilayer optical film 20, and an optional second multilayer optical film 30 disposed on the barrier coating 50.

[0130] List of Exemplary Embodiments

[0131] In the first embodiment, a light-shielding article is provided. The light-shielding article includes: a) a first multilayer optical film composed of at least a plurality of alternating first and second polymer optical layers that collectively reflect, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, on average, at least 70, 80, 90, or 95 percent of the incident visible light over a wavelength range of at least 400 nanometers (nm) to 700 nm, the first multilayer optical film having a first major surface; and b) a second multilayer optical film disposed on the first multilayer optical film, the second multilayer optical film composed of at least a plurality of alternating first and second inorganic optical layers that collectively reflect and absorb, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, on average, at least 50, 60, 70, 80, 90, or 95 percent of the incident ultraviolet light over a reflection bandwidth of at least 30 nanometers at a wavelength within the wavelength range of 190 nm to 400 nm. The light-shielding article transmits, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, on average, at least 70, 80, 90, or 95 percent of the incident radio frequency waves over at least one wavelength range of 1 millimeter (mm) to 10 mm, 10 mm to 100 mm, or 100 mm to 1000 mm.

[0132] In a second embodiment, another light-shielding article is provided. This light-shielding article comprises: a) a first multilayer optical film comprising at least a plurality of alternating first and second polymer optical layers that collectively reflect, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, on average at least 70, 80, 90, or 95 percent of incident visible light over a wavelength range of at least 400 nanometers (nm) to 700 nm, the first multilayer optical film having a first major surface; and b) a barrier coating disposed on the first major surface of the multilayer optical film. The barrier coating comprises at least one dyad comprising a (co)polymer layer overlapping the first major surface of the multilayer optical film and an inorganic layer overlapping the (co)polymer layer, an outer (co)polymer layer overlapping the at least one dyad, and optionally at least one outer inorganic layer overlapping the outer (co)polymer layer. This light-shielding article transmits, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, on average at least 70, 80, 90, or 95 percent of incident radio frequency waves within at least one wavelength range of 1 mm to 10 mm, 10 mm to 100 mm, or 100 mm to 1000 mm. This light-shielding article transmits, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, on average a maximum of 50, 60, or 70 percent of incident ultraviolet light over a reflection bandwidth that is at least 30 nanometers in wavelength within a wavelength range of 190 nm to 400 nm.

[0133] In a third embodiment, a light-shielding article according to the second embodiment is provided, the light-shielding article further comprising a second multilayer optical film disposed on the barrier coating, the second multilayer optical film comprising at least a plurality of alternating first and second inorganic optical layers that collectively reflect and absorb, at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, on average at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light over a reflection bandwidth that is at least 30 nanometers in wavelength within a wavelength range of 190 nm to 400 nm.

[0134] In the fourth embodiment, a light-shielding article according to the second or third embodiment is provided, and at least one diad is a plurality of diads, and optionally, the plurality of diads are two diads, three diads, four diads, five diads, or six diads.

[0135] In the fifth embodiment, a light-shielding article according to any one of the second to fourth embodiments is provided, and at least one inorganic layer is formed of an inorganic material selected from silicon oxide, silica alumina oxide, silicon oxynitride, gallium oxide, magnesium oxide, niobium oxide, titanium dioxide, yttrium oxide, zinc oxide, tin oxide, nickel oxide, tungsten oxide, aluminum-doped zinc oxide, indium tin oxide, zirconium oxide, zirconium oxynitride, hafnia, aluminum oxide, alumina-doped silicon oxide, lanthanum fluoride, neodymium fluoride, aluminum fluoride, magnesium fluoride, calcium fluoride, or a combination thereof.

[0136] In the sixth embodiment, a light-shielding article according to any one of the second to fifth embodiments is provided, and each (co)polymer layer in at least one diad contains a (co)polymer selected from olefin (co)polymers, (meth)acrylate (co)polymers, urethane (co)polymers, fluoropolymers, silicone (co)polymers, or combinations thereof.

[0137] In the seventh embodiment, a light-shielding article according to any one of the second to sixth embodiments is provided, and the article exhibits atomic oxygen degradation of less than 1×10 -20 mg / atom, 1×10 -21 mg / atom, or 1×10 -22 mg / atom when tested according to the atomic oxygen degradation test.

[0138] In the eighth embodiment, a light-shielding article according to any one of the first to seventh embodiments is provided, and the polymer optical layer of the first multilayer optical film includes a fluoropolymer, polyethylene terephthalate (PET), CoPMMA, a polypropylene (PP) copolymer, a polyethylene copolymer, PMMA, a blend of PMMA and polyvinylidene fluoride (PVDF), an acrylate copolymer, polyurethane, PEN, or a combination thereof.

[0139] In the ninth embodiment, a light-shielding article according to any one of the first to eighth embodiments is provided, and the polymer optical layer of the first multilayer optical film includes a copolymer of tetrafluoroethylene (TFE), hexafluoropropylene (HFP), and vinylidene fluoride; a copolymer of TFE, HFP, vinylidene fluoride, and perfluoropropyl vinyl ether (PPVE); polyvinylidene fluoride (PVDF); an ethylene chlorotrifluoroethylene (ECTFE) polymer; ethylene tetrafluoroethylene (ETFE); a perfluoroalkoxy alkane (PFA) polymer; a fluorinated ethylene propylene (FEP) polymer; polytetrafluoroethylene (PTFE); a copolymer of TFE, HFP, and ethylene: polyvinyl fluoride (PVF); and a fluoropolymer independently selected from the group consisting of combinations thereof.

[0140] In the tenth embodiment, a light-shielding article according to any one of the first or third to ninth embodiments is provided, and the first optical layer of the second multilayer optical film includes at least one of niobium oxide, titanium oxide, silicon oxynitride, molybdenum oxide, tungsten oxide, silicon nitride, indium tin oxide, hafnium oxide, tantalum oxide, zirconium oxynitride, zirconium oxide, aluminum zinc oxide, or zinc oxide, and the second optical layer includes at least one of silicon oxide, aluminum oxide, aluminum fluoride, magnesium fluoride, calcium fluoride, indium tin oxide, aluminum zinc oxide, or zinc oxide.

[0141] In the eleventh embodiment, a light-shielding article according to any one of the first or third to tenth embodiments is provided, a second multilayer optical film is present, the first optical layer of the second multilayer optical film contains at least one of niobium oxide or titanium oxide, and the second optical layer contains silicon oxide.

[0142] In the twelfth embodiment, a light-shielding article according to any one of the first or third to eleventh embodiments is provided, a second multilayer optical film is present, and it has a thickness of 200 nm to 900 nm.

[0143] In the thirteenth embodiment, a light-shielding article according to any one of the first or third to twelfth embodiments is provided, a second multilayer optical film is present, and each of the first optical layer and the second optical layer of the second multilayer optical film independently has a thickness of 5 nm to 200 nm.

[0144] In the fourteenth embodiment, a light-shielding article according to any one of the first or third to thirteenth embodiments is provided, a second multilayer optical film is present, and it is formed of a total of 3 to 21 layers of the first and second optical layers.

[0145] In the fifteenth embodiment, a light-shielding article according to any one of the first or third to fourteenth embodiments is provided, a second multilayer optical film is present, and a plurality of alternating first and second inorganic optical layers of the second multilayer optical film collectively reflect and absorb at least 60, 70, 80, 90, or 95 percent, on average, of incident ultraviolet light over a reflection bandwidth of at least 50 nanometers, 75 nanometers, 100 nanometers, 125 nanometers, 150 nanometers, or 175 nanometers in the wavelength range of 190 nm to 400 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°.

[0146] In the sixteenth embodiment, a light-shielding article according to any one of the first to fifteenth embodiments is provided, and it further includes a substrate attached to at least a part of the second main surface of the first multilayer optical film.

[0147] In the 17th embodiment, a light-shielding article according to any one of the 1st to 16th embodiments is provided, and further includes an adhesive disposed on at least a part of the second main surface of the first multilayer optical film, an adhesive disposed on at least a part of the base material on the opposite side of the first multilayer optical film, or both of them.

[0148] In the 18th embodiment, a light-shielding article according to any one of the 1st to 17th embodiments is provided, and at 50 ° C. and a relative humidity (RH) of 100%, a maximum of 5 × 10 -3 or a maximum of 5 × 10 -5 g / m 2 / day of water vapor transmission rate (WVTR).

[0149] In the 19th embodiment, a light-shielding article according to any one of the 1st to 18th embodiments is provided, and at least one (co)polymer layer or the outer (co)polymer layer in at least one diad further includes an ultraviolet absorber, a hindered amine light stabilizer, an antioxidant, or a combination thereof.

[0150] In the 20th embodiment, a light-shielding article according to the 19th embodiment is provided, and the ultraviolet absorber is selected from benzotriazole compounds, benzophenone compounds, triazine compounds, or combinations thereof.

[0151] In the 21st embodiment, a light-shielding article according to any one of the 1st to 20th embodiments is provided, and the plurality of alternating first and second polymer optical layers collectively reflect at least 70, 80, 90, or 95 percent of the incident infrared light over a reflection bandwidth of at least 30 nanometers in the wavelength range of 700 nm to 1600 nm and / or 700 nm to 2000 nm at at least one incident light angle of 0 °, 15 °, 30 °, 45 °, 60 °, or 75 °.

[0152] In the 22nd embodiment, a light-shielding article according to any one of the 1st to 21st embodiments is provided, and exhibits a desired composite dielectric loss.

[0153] In the 23rd embodiment, a light-shielding article according to any one of the 1st to 22nd embodiments is provided, exhibiting a desired composite dielectric constant.

[0154] In the 24th embodiment, a light-shielding article according to any one of the 1st to 23rd embodiments is provided, showing that after exposure to a certain dose of ultraviolet light, the average reflectance of wavelengths from 400 nm to 700 nm passing through the article decreases by less than 20%, less than 10%, less than 5%, or less than 1%.

[0155] In the 25th embodiment, an electromagnetic receiver and / or emitter is provided. This electromagnetic receiver and / or emitter includes a light-shielding article according to any one of the 1st to 24th embodiments attached to at least a part of the electromagnetic receiver and / or emitter.

Examples

[0156] Unless otherwise specified or obvious from the context, all parts, percentages, ratios, etc. in the examples and other parts of this specification are by weight.

Table 1

[0157] Spectral Characteristics Measurement Test: Spectral transmission and reflection were measured using a spectrophotometer (obtained from PerkinElmer, Inc. (Waltham, MA) under the trade name "LAMBDA 1050"). Except for Comparative Example 3 where the PET substrate faced the light source and Comparative Example 4 where the pre-masked side faced the light source, the coated surface of the example faced the light source during measurement. The measured spectral reflection and transmission were reported in the reflectance and absorbance result tables and the transmittance result tables as average percentages over the wavelength range. The reflection measured for the first multilayer optical film DF2000F, which was used in many of the examples and comparative examples, was also reported in the reflectance measurement table of the first multilayer optical film.

[0158] Spectral characteristic modeling test: Since the substrate can affect the UV spectral characteristics of the measured film, especially in the case of UV-absorbing substrates such as DF2000F, it can affect transmission and absorption. Therefore, in order to better estimate the UV reflection and absorption of the UV-absorbing coating and the reflective coating, the reflection, transmission, and absorption of the UV-absorbing coating and the reflective coating (Examples 1, 3, and 4, and Comparative Example 1) were modeled. To perform this modeling, Test Samples 1, 2, and 3 were measured with an ellipsometer (obtained from J.A. Woolam (Lincoln, NE) under the trade name "RC2 Ellipsometer") to measure the spectral refractive index (n) and extinction coefficient (k) values of the deposited TiO2, SiO2, and SR833 materials. Then, the n and k obtained above were input into optical modeling software (obtained from The Thin Film Center (Tucson, AZ) under the trade name "Essential MaCleod"), and it was used to calculate the reflection spectrum, transmission spectrum, and absorption spectrum of the multilayer optical film prepared as described below. All structures were modeled using a PET substrate. Note that this stage of the modeling only calculates the transmission, reflection, and absorption of the coating (e.g., SiO2, TiO2, or SR833 layer), and the modeling does not calculate the absorption or reflection of the polymer film (e.g., FEP) or the substrate material (e.g., DF2000F).

[0159] For the samples of Examples 3 and 4 in which the additional polymer film is included in the sample layer, the contribution of these polymer films to absorption was measured in the following manner. First, the absorption spectrum of FEP (obtained by measuring a film without FEP coating in the above spectral property measurement test) was multiplied by the modeled transmittance of the optical coating (obtained as described in the previous paragraph), and then divided by 100 (to maintain the unit of %), to calculate the absorption of the FEP film. Next, in the case of Example 3, the absorption of FEP calculated from the modeled transmittance was subtracted, and the absorption spectrum of the uncoated film of Preparation Example 3 (obtained by measuring an uncoated 1-mil 50:50 PMMA UVA MB:CoPMMA film using the above spectral property measurement test) was multiplied by the remaining transmittance value, and then divided by 100 (to maintain the unit of %), to calculate the absorption of the film of Preparation Example 3. For Example 3, the sum of the contributions to absorption from the FEP film and the film of Preparation Example 3 was added to the modeled absorption value to obtain the final modeled absorption spectrum. For Example 4, only the absorption of FEP was added to the modeled absorption to obtain the final modeled absorption spectrum.

[0160] In the case of Comparative Example 1, the UV absorption coating on the substrate does not completely block UV wavelengths of light less than 400 nm, where absorption and reflection by the DF2000F substrate can be significant. In this case, some light is absorbed and reflected by the DF2000F substrate in addition to the absorption that occurs in the coating, so the measured absorption and reflection include contributions from both the DF2000F substrate and the coating, but the purpose of the test is to evaluate the absorption of the coating only. To account for the influence of the substrate, the measured absorption and reflection of the uncoated DF2000F substrate were multiplied by the modeled transmission of the coating (see the section on Spectral Characterization Modeling Tests below), and this product was divided by 100 (to maintain the unit of %), to estimate the contribution of the DF2000F substrate to absorption and reflection. These are reported in the reflectance and absorptance results table as modeled DF2000F A(%) and modeled DF2000 F R(%). These modeled absorption and reflection spectra of DF2000F were then subtracted from the measured absorption and reflection spectra of Comparative Example 1, respectively, to calculate a more accurate representation of the measured absorption and reflection of the coating, which is reported in the reflectance and absorptance results table as corrected measurement A(%) and corrected measurement R(%).

[0161] The results of modeling of reflection, absorption, and transmission are reported in the reflectance and absorptance results table and the transmittance results table as average percent over the wavelength range.

[0162] Solar light aging test: Samples were exposed in an Atlas Ci5000 Weather-Ometer (obtained from AMETEK (Berwyn, PA)) using a xenon arc lamp equipped with inner and outer quartz filters. The set of quartz filters minimizes the attenuation of the spectral power distribution of the xenon lamp, thereby providing an approximation close to the shape of solar output (ASTM E490). To increase the dose accumulation rate, samples were exposed on custom-made stainless steel and aluminum extension holders. The extension holders move the exposure surface from a position 19 inches (48.3 cm) away from the lamp core to a position 13.5 inches (34.3 cm) away from the lamp core. The irradiance was controlled at 1.5 W / m 2 at 340 nm on the rack surface and measured at 2.6 W / m 2 at 340 nm in the extended sample plane. The ambient air temperature inside the weatherometer was controlled at 48 °C, the black panel thermometer (BPT) was controlled at 75 °C on the rack surface, measured at approximately 95 °C on the sample surface, and the relative humidity was controlled at 30%. Samples were exposed without backing. Samples were exposed to an integrated irradiance of 425 megajoules per square meter (MJ / m 2 ) and 850 MJ / m 2 at 250 - 385 nm. Except for Comparative Example 3 where the PET substrate faced the light source and Comparative Example 4 where the pre-masked side of DF2000F faced the light source, the samples were oriented such that the coated surface faced the light source.

[0163] The change in reflectance was calculated as follows.

Equation

[0164] where R fresh is the average reflectance from 400 to 700 nm before solar light aging, and R aged is the average reflectance from 400 to 700 nm after the above exposure. The results of the solar light aging test are summarized in the solar light aging result table.

[0165] RF Transmission Test: The RF transmission was directly measured at 27 GHz and 78 GHz using a free-space measurement system called a quasi-optical measurement system, designed and built by Thomas Keating Ltd (Billingshurst, United Kingdom). This quasi-optical system was combined with a Keysight Vector Network Analyzer (VNA) (obtained from Keysight Technologies (Santa Rosa, CA)). Transmission and reflection were directly measured as complex scattering parameters (S-parameters). The magnitude of the S-parameter transmission coefficient (S12) was reported at 11.1 mm (27 GHz) at three angles of incidence of 0°, 30°, and 60°, and at 3.8 mm (78 GHz) at two angles of incidence of 0° and 30°.

[0166] In the quasi-optical measurement system, two corrugated horn antennas and four mirrors were used to focus the Gaussian beam. Electromagnetic signals in the frequency bands of 22 - 33 GHz and 60 - 90 GHz from the VNA were transmitted at port 1 through the corrugated horn antenna, then the Gaussian beam was focused by two mirrors, then passed through the sample holder, then the beam was refocused between two or more mirrors and received by the second corrugated horn and sent back to the VNA at port 2. The sample holder at the center of the quasi-optical system can be rotated about its axis to measure transmission and reflection at multiple angles of incidence from 0° to 60°.

[0167] Atomic oxygen degradation test: The test specimens and Kapton HN film pieces used as control specimens were cut into squares of 1.5 inches × 1.5 inches (3.81 cm × 3.81 cm). Before weighing, they were placed in a vacuum oven (an oven obtained from Avantor (Radnor, PA) under the product name "VWR 1410D") evacuated using a vacuum pump (obtained from Sterlitech Corporation (Auburn, WA) under the product name "Rocker 400 Vacuum Pump") and held at 80 °C and -70 kPa for at least 12 hours for dehydration, and then the mass was measured. Then, they were weighed using a high-precision balance (obtained from Sartorius Corporation (Bohemia, NY) under the product name "PRACTUM64-1S") capable of measuring the mass up to 0.1 mg. Next, the test specimens and control specimens were placed on a 1 / 4-inch (0.635 cm) thick glass plate and then covered with a 1 / 8-inch (0.3175 cm) glass masking plate with a 1-inch (2.54 cm) diameter circular hole cut out. The masking plate was placed such that the test specimens and control specimens were at the center under the circular hole. Then, this assembly was placed on the energized electrode of the plasma reactor in the batch plasma system. The test specimens and control specimens were exposed to oxygen plasma using a batch plasma reactor (obtained from Plasma-Therm 5 LLC (St. Petersburg, FL) under the product name "PLASMA-THERM 3032"). This apparatus was configured for reactive ion etching using a 26-inch (66.0 cm) low-power electrode and central gas pumping. The chamber was pumped with a Roots blower (obtained from Edwards Engineering under the product name "EH1200") enhanced by a dry mechanical pump (obtained from Edwards Engineering (Burgess Hill, UK) under the product name "iQDP80"). The RF power was supplied by a 3 kW, 13.56 MHz solid-state generator 10 (obtained from Advanced Energy Industries (Fort Collins, CO) under the product name "RFPP RF30S"). This system had a nominal base pressure of 5 millitorr (0.67 Pa).The gas flow rate was controlled by an MKS flow regulator (obtained from MKS Instruments (Andover, MA)).

[0168] After pumping down to the base pressure, oxygen (O2) was introduced at 500 standard cubic centimeters per minute (sccm). After the gas flow in the reactor stabilized, rf power (2000 watts) was applied to the electrodes to generate plasma. The sample was exposed to the ignited plasma for a total exposure time of 4 hours. This typically involved 4 exposures of 1 hour each. After each plasma exposure was completed, the chamber was vented to the atmosphere and the test specimens and control specimens were removed from the chamber. The mass of each test specimen and control specimen was measured again, and the change in mass was recorded. If additional exposure time was required to complete 4 hours of exposure, the sample was returned to the test fixture as described above and carefully centered so as to hold the same position under the opening of the glass masking plate. Since non-linear mass loss of KAPTON HN was sometimes observed during long or multiple exposures, a new unexposed piece of KAPTON HN was used for each exposure. After the sample was exposed for a total of 4 hours, the sample and control specimens were dehydrated in a vacuum oven for 12 hours again and then their final mass measurements were taken. For each exposure, the mass loss of the KAPTON HN evidence for that exposure was divided by the density of KAPTON HN (1.412 g / cm 3 ) and the atomic oxygen erosion yield of KAPTON HN (2.81×10 -24 cm 3 / atom) to determine the effective atomic oxygen fluence (number of atoms) of the plasma treatment. Then, the total mass loss of the test specimens after 4 hours of exposure was divided by the total effective atomic oxygen fluence to measure the mass loss per effective atomic oxygen atom (mg / atom). Thus, atomic oxygen degradation is quantified as the mass loss per effective atomic oxygen atom (mg / atom). Preparation Example

[0169] Preparation Example 1: A barrier film was prepared by coating FEP with a laminate of a first polymer layer, an inorganic boron-doped silicon oxide (SiOx:B) barrier layer, a second polymer layer, and a second SiOx:B layer on a vacuum coater similar to the coater described in U.S. Patent No. 5,440,446 (Shaw et al.) and U.S. Patent No. 7,018,713 (Padiyath et al.). The individual layers were formed as follows.

[0170] Layer 1 (first polymer layer): A 350-meter-long PET carrier film was loaded into a roll-to-roll vacuum treatment chamber. An FEP substrate sheet was taped to the PET carrier using polyimide tape. The chamber was pumped down to a pressure of less than 1×10 -5 torr (1.3x10 -3 Pa). While maintaining the back side of the PET carrier film in contact with a coating drum cooled to -23°C, a web speed of 2.5 meters per minute was maintained.

[0171] The front surface of the substrate was treated with nitrogen plasma at a plasma power of 0.15 kW while keeping the back side of the PET carrier film in contact with the drum. Next, the front surface of the substrate was coated with SR833S. The monomer was degassed under a vacuum of 20 millitorr (2.67 kPa) before coating, placed in a syringe pump (obtained from Harvard Apparatus (Holliston, MA)), and injected at a flow rate of 1.0 milliliter per minute into a heated vaporization chamber maintained at 260°C via an ultrasonic nebulizer (obtained under the trade name "MicroMist" from Sono-Tek (Milton, NY)) operating at a frequency of 60 kHz.

[0172] The resulting monomer vapor stream was condensed onto the film surface and electron beam crosslinked using a multifilament electron beam curing gun (obtained from PCT Ebeam and Integration (Davenport, IA)) operating at 7.0 kV and 4 mA to form a 750 nm thick first polymer layer. Next, the film web was advanced to expose additional sample coatings and the film and substrate were wound onto a film roll.

[0173] Layer 2 (inorganic layer): After the first polymer deposition and winding of the film and substrate, without removing the film roll or substrate from the vacuum processing chamber, the film was unwound and the substrate was returned onto a chill roll such that the back side of the PET carrier film was brought into contact with a drum. Next, a SiOx:B layer was deposited by reactive magnetron sputtering onto the first polymer layer. With the cathode housing a Si:B sputtering target, one cathode was controlled using one direct current (DC) power supply (obtained from Advanced Energy (Denver, CO) under the trade name "Pinnacle Plus 5kW").

[0174] During sputter deposition, a predetermined oxygen flow to the cathode was manually maintained. Using this pulsed DC power supply, a gas mixture containing 110 standard cubic centimeters per minute (sccm) of argon and 32 sccm of oxygen at a line speed of 7.2 feet per minute (2.19 meters per minute) and a sputter pressure of 3.1 millitorr, the Si:B target was sputtered at 2800 watts of power with a 175 kHz pulse and a duration of 1.5 microseconds. Thereby, a 25 nm thick SiOx:B layer was deposited onto the first polymer layer of layer 1.

[0175] Layer 3 (second polymer layer): Immediately after the SiOx:B layer deposition, with the back side of the PET carrier film still in contact with the drum, SR833S was condensed onto layer 2 and crosslinked as described for layer 1. Thereby, a second polymer layer of 750 nm was provided on layer 2. Next, the film web was advanced to expose it to additional sample coating, and the film and substrate were wound onto a film roll.

[0176] Preparation Example 2: The film of Preparation Example 1 was coated with an additional inorganic layer (layer 4). After the second polymer deposition and the winding of the film and substrate, without removing the film roll or substrate from the vacuum processing chamber, the film was unwound and the substrate was returned onto the chill roll so that the back side of the PET carrier film was in contact with the drum. Then, a SiOx:B layer was deposited on the second polymer layer by reactive magnetron sputtering. With the cathode housing a Si:B sputtering target, one cathode was controlled using one direct current (DC) power supply.

[0177] Preparation Example 3: A multilayer film of PP and 50:50 (weight:weight) (PMMA UVA MB):CoPMMA was prepared using two twin-screw extruders and a 3-layer multilayer film extrusion die. The film was extruded in an A / B / A structure, where the A layer was made of PP and the B layer was made of 50:50 (weight:weight) (PMMA UVA MB):CoPMMA. The A layer was extruded using an 18 mm twin-screw extruder (obtained from Leistritz Advanced Technologies Corp. (Allendale, NJ) under the trade name "Micro-18") at an extruder final zone temperature of 250 °C and a screw speed of 100 RPM. The B layer was extruded from an 18 mm twin-screw extruder (obtained from Thermo Fisher Scientific (Waltham, MA) under the trade name "Micro 18 Extruder") at an extruder final zone temperature of 250 °C and a screw speed of 100 RPM. These molten streams were combined in a 3-layer A / B / A extrusion die, and the polymer melt was extrusion cast onto a cooling roll set at 50 °C and wound onto a 3-inch (7.6 cm) diameter cardboard core. The speed of the wheel was adjusted so that a final film with an A layer thickness of 0.5 mil (12.7 micrometers) and a B layer thickness of 1 mil (25.4 micrometers) was obtained. The PP skin was then removed, leaving a final film of only 1 mil (25.4 micrometers) of 50:50 (weight:weight) (PMMA UVA MB):CoPMMA.

[0178] Preparation Example 4: A vapor-coated multilayer optical film composed of 5 pairs of alternating layers of 58.8 nm SiO2 and 36.1 nm TiO2 was prepared on the substrate of Preparation Example 1 in the following manner. The vapor coater used was a Denton Vacuum Optical Coater consisting of a 5-planet planetary drive system located approximately 30 inches (76.2 cm) above a 4-pocket Temescal electron beam gun (obtained from Ferro Tec Corporation (Livermore, CA)). The planetary drive system is designed to hold the substrate perpendicular to the evaporation source and move the disk in a planetary motion in and out of the evaporation plume during deposition. The actual process for coating consists of the following multiple steps. a) The vapor coater was vented to the atmosphere and one of the five planets was removed. The substrate was prepared for coating by adhering / taping the substrate to the planet with polyimide tape. The sample was oriented so that the previously coated surface of Preparation Example 1 was exposed to the coating. b) The planet was reinstalled and, if necessary, the other four planets were similarly prepared and also reinstalled in the coater. c) The chamber was closed and evacuated to a vacuum level of less than 2 x 10 -5 torr (2.7 x 10 -3 Pa). d) When the vapor coater reached a sufficiently low vacuum, the material was ion beam treated using a Kaufman-type ion source at a voltage of 400 V for approximately 10 minutes as a pretreatment to the substrate to deposit a vapor coating on the substrate before applying the oxide film. e) Oxygen gas was added via an MKS mass flow controller (obtained from MKS Instruments, Inc. (Andover, MA)) to 4.0 x 10 -5 torr (5.3 x 10 -3The pressure of (Pa) was obtained. This was typically about 10 sccm for the added oxygen gas. f) The coating was prepared and the planetary drive system was started to move around the coater at a rotational speed of about 60 rpm to achieve a high level of uniformity on the attached substrate. g) The Temescal electron beam gun (e-gun) power supply was energized. A voltage of 10 kV and a current of several milliamperes were applied to the filament of the electron gun to heat the source material inside the electron gun. The light source was heated and controlled by the Eddy Company Optical Monitoring System (OMS) (manufactured by Eddy Company, Apple Valley, CA). The source was heated until the desired deposition rate of the material was achieved. For TiO2, this rate was 2 angstroms per second (A / s), and for SiO2, this was 4 A / s. When the desired deposition rate of the material was achieved and stabilized, the shutter that separates the source from the planet was opened, the rate was maintained via the OMS until the desired optical thickness was achieved, the shutter was closed when the desired optical thickness was achieved, and the OMS cut off the power to the e-beam source. h) The main power supply to the power source was turned off and the source was cooled for about 10 minutes. i) This process was repeated for additional layer / material types until the completely desired multilayer optical film was deposited. j) Next, the chamber was returned to atmospheric pressure with N2 gas, each planet was removed, and the substrate was removed from each planet.

[0179] The structure of Preparation Example 4 is summarized in the structure table of the following examples.

[0180] Preparation Example 5: The film of Preparation Example 2 was coated with 200 nm of TiO2 on the previously coated side using the same vapor coating method as the coating method described in Preparation Example 4. Test sample

[0181] Test Sample 1: Test Sample 1 was prepared in the same manner as Preparation Example 4, except that a 70-nm-thick TiO2 layer was deposited on a silicon chip.

[0182] Test sample 2: Test sample 2 was prepared in the same manner as Preparation Example 4, except that a SiO2 layer with a thickness of 115 nm was deposited on the silicon chip.

[0183] Test sample 3: Test sample 3 was prepared in the same manner as Preparation Example 1, except that a PET substrate was used and only a single polymer layer of SR833 with a thickness of 750 nm was deposited.

[0184] [Examples] Example 1: Example 1 was prepared in the same manner as Preparation Example 4, except that a DF2000F substrate was used instead of the substrate of Preparation Example 1. Before coating DF2000F, the pre-mask was removed from the sample, and the coating was deposited on the side that had been previously pre-masked.

[0185] The structure of Example 1 is summarized in the structure table of the following examples.

[0186] Example 2: Example 2 was prepared in the same manner as Preparation Example 2, except that DF2000F was used as the substrate material instead of FEP. Before coating DF2000F, the pre-mask was removed from the sample, and the coating was deposited on the side that had been previously pre-masked.

[0187] Example 3: Example 3 was prepared by obtaining a piece of DF2000F, removing the pre-mask, then placing the film of Preparation Example 3 on the previously pre-masked side of the DF2000F, and then placing the film of Preparation Example 5 on the surface of the film of Preparation Example 3 such that the uncoated surface of Preparation Example 5 contacts the outer surface of Preparation Example 3.

[0188] Example 4: Example 4 was prepared by obtaining a piece of DF2000F, removing the pre-mask, and then placing the film of Preparation Example 4 on the previously pre-masked side of the DF2000F. [Comparative Examples]

[0189] Comparative Example 1: One piece of DF2000F was obtained, the premask was removed, and then the side that had previously been covered by the premask was coated with 200 nm of TiO2 by the coating method outlined in Preparation Example 4 to prepare Comparative Example 1. The structure of Comparative Example 1 is summarized in the structure table of the following examples.

[0190] Comparative Example 2: The PET substrate was coated with a metal reflective mirror. Using the modified coating process, Comparative Example 2 was prepared using the same vapor coater as described for Preparation Example 4. The actual process for coating consisted of the following multiple steps. a) The vapor coater was vented to the atmosphere and one of the five planets was removed. The substrate was typically a substrate for coating by adhering / taping to the planet with a polyimide tape. The PET substrate used for these samples had one side pretreated by the supplier, and the substrate was taped to the planet so that the non-pretreated side of the PET was coated by the vapor coating process. b) The planet was reinstalled, and the other four planets were similarly prepared and reinstalled in the coater as needed. c) The chamber was closed and 2x10-5 Torr (2.7x10 -3Pa) It was evacuated to a vacuum level below. d) When the vapor coater reaches a sufficiently low vacuum state, as a pretreatment of the substrate to attach the vapor deposition coating before applying the coating to the substrate, the material was ion beam treated using a Kaufman-type ion source at a voltage of 400 V for about 10 minutes. e) To prepare the coating and achieve a high level of uniformity on the attached substrate, the planetary drive system was started and moved around the coater at a rotational speed of about 60 rpm. f) The Temescal electron beam gun power supply was energized. A voltage of 10 kV and a current of several milliamperes were applied to the filament of the electron gun to heat the metal source material inside the electron gun. The output of the electron beam, and thus the heating of the metal source, was controlled via an Inficon IC5 Deposition Rate Controller (obtained from Inficon (Bad Ragaz, Switzerland)) and a Quartz Crystal Monitor (QCM) (obtained from Inficon (Bad Ragaz, Switzerland)). g) The QCM has a crystal that vibrates at 6 MHz. When in the coated state, this frequency decreased as a function of the density and acoustic impedance of the deposited material. There was also a tooling factor depending on the geometry of the QCM crystal and the substrate on which the coating was deposited. h) The power of the e-beam was increased to heat the deposited material. When the desired speed was achieved and stabilized, the shutter that separates the source from the planet was opened, the speed was maintained via the IC5 until the desired physical thickness was achieved, the shutter was closed when the desired physical thickness was achieved, and the IC5 turned off the power of the e-beam source. The desired deposition rates for Al and Cr were 1 Å / s and 2 Å / s, respectively. i) The main power supply to the power source was turned off and the source was cooled for about 10 minutes. j) If an additional layer was required, steps e - h were repeated for the appropriate material and thickness. k) Then, the chamber was returned to atmospheric pressure with N2 gas, each planet was removed, and the substrate was removed from each planet.

[0191] The structure of Comparative Example 2 is summarized in the following structure table of comparative examples.

[0192] Comparative Example 3: Comparative Example 3 was a film of DF2000F from which the premask was removed. [Table 2] [Table 3] [Table 4] [Table 5] [Table 6] [Table 7] [Table 8] [Table 9] [Table 10]

[0193] Although specific embodiments have been illustrated and described herein, it will be understood by those skilled in the art that the specific embodiments shown and described may be replaced by various alternative implementations and / or equivalent implementations without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Accordingly, the present disclosure is intended to be limited only by the claims and their equivalents.

[0194] Furthermore, all publications and patents referenced herein are hereby incorporated by reference in their entirety to the same extent as if each individual publication or patent were specifically and individually indicated to be incorporated by reference. In the event of inconsistencies or conflicts between the incorporated portions of the reference documents and the present application, the information in the foregoing description shall prevail.

[0195] Various exemplary embodiments have been described. These embodiments and other embodiments are within the scope of the following claims.

Claims

1. a) A first multilayer optical film comprising at least a plurality of alternating first and second polymer optical layers that collectively reflect, on average, at least 70, 80, 90, or 95 percent of incident visible light in the wavelength range of at least 400 nanometers (nm) to 700 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°, the first multilayer optical film having a first main surface, b) A second multilayer optical film disposed on the first multilayer optical film, comprising at least a plurality of alternating first and second inorganic optical layers that collectively reflect and absorb, on average, at least 50, 60, 70, 80, 90, or 95 percent of incident ultraviolet light over a reflection bandwidth of at least 30 nanometers in the wavelength range of 190 nm to 400 nm at at least one incident light angle among 0°, 15°, 30°, 45°, 60°, or 75°, and Light-shielding articles including, The light-shielding article transmits, on average, at least 70, 80, 90, or 95 percent of incident radio frequency waves within at least one wavelength range of 1 mm to 10 mm, 10 mm to 100 mm, or 100 mm to 1000 mm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°. Light-shielding items.

2. A light-shielding article according to claim 1, further comprising a barrier coating disposed between the first multilayer optical film and the second multilayer optical film and on the first main surface of the first multilayer optical film, the barrier coating comprising at least one dyad consisting of a (co)polymer layer overlapping the first main surface of the multilayer optical film and an inorganic layer overlapping the (co)polymer layer, an outer (co)polymer layer overlapping the at least one dyad, and optionally at least one outer inorganic layer overlapping the outer (co)polymer layer.

3. The light-shielding article according to claim 2, which exhibits atomic oxygen degradation of less than 1 × 10⁻²⁰ mg / atom, 1 × 10⁻²¹ mg / atom, or 1 × 10⁻²² mg / atom when tested according to the atomic oxygen degradation test.

4. The light-shielding article according to any one of claims 1 to 3, wherein the polymer optical layer of the first multilayer optical film comprises a fluoropolymer, polyethylene terephthalate (PET), CoPMMA, polypropylene (PP) copolymer, polyethylene copolymer, PMMA, a blend of PMMA and polyvinylidene fluoride (PVDF), acrylate copolymer, polyurethane, PEN, or a combination thereof.

5. The light-shielding article according to any one of claims 1 to 3, wherein the polymer optical layer of the first multilayer optical film comprises a copolymer of tetrafluoroethylene (TFE), hexafluoropropylene (HFP), and vinylidene fluoride; a copolymer of TFE, HFP, vinylidene fluoride, and perfluoropropyl vinyl ether (PPVE); polyvinylidene fluoride (PVDF); ethylene chlorotrifluoroethylene (ECTFE) polymer; ethylene tetrafluoroethylene (ETFE); perfluoroalkoxyalkane (PFA) polymer; fluorinated ethylene propylene (FEP) polymer; polytetrafluoroethylene (PTFE); a copolymer of TFE, HFP, and ethylene; polyvinyl fluoride (PVF); and a fluoropolymer independently selected from the group consisting of combinations thereof.

6. The light-shielding article according to any one of claims 1 to 3, wherein the first optical layer of the second multilayer optical film comprises at least one of niobium oxide, titanium oxide, silicon oxynitride, molybdenum oxide, tungsten oxide, silicon nitride, indium tin oxide, hafnium oxide, tantalum oxide, zirconium oxynitride, zirconium oxide, aluminum zinc oxide, or zinc oxide, and the second optical layer comprises at least one of silicon oxide, aluminum oxide, aluminum fluoride, magnesium fluoride, calcium fluoride, indium tin oxide, aluminum zinc oxide, or zinc oxide.

7. The light-shielding article according to any one of claims 1 to 3, wherein the second multilayer optical film is present, the first optical layer of the second multilayer optical film comprises at least one of niobium oxide or titanium oxide, and the second optical layer comprises silicon oxide.

8. The light-shielding article according to any one of claims 1 to 3, wherein the second multilayer optical film is present and has a thickness of 200 nm to 900 nm.

9. The light-shielding article according to any one of claims 1 to 3, wherein the second multilayer optical film is present and is formed from a total of 3 to 21 first and second optical layers.

10. A light-shielding article according to any one of claims 1 to 3, wherein the second multilayer optical film is present, and the plurality of alternating first and second inorganic optical layers of the second multilayer optical film collectively reflect and absorb, on average, at least 60, 70, 80, 90, or 95 percent of incident ultraviolet light over a reflection bandwidth of at least 50 nanometers, 75 nanometers, 100 nanometers, 125 nanometers, 150 nanometers, or 175 nanometers in the wavelength range of 190 nm to 400 nm, at at least one incident light angle among 0°, 15°, 30°, 45°, 60°, or 75°.

11. A light-shielding article according to any one of claims 1 to 3, further comprising an adhesive disposed on at least a portion of the second main surface of the first multilayer optical film, an adhesive disposed on at least a portion of the substrate on the opposite side of the first multilayer optical film, or both.

12. 425 megajoules / cm² (MJ / cm) ２ ) or 850 MJ / cm ２ A light-shielding article according to any one of claims 1 to 3, wherein, after exposure to ultraviolet light of a dose, the average transmittance of wavelengths from 400 nm to 700 nm passing through the article decreases by less than 20%, less than 10%, less than 5%, or less than 1%.

13. The light-shielding article according to any one of claims 1 to 3, wherein at least one (co)polymer layer within the at least one dyad or the outer (co)polymer layer further comprises a UV absorber, a hindered amine light stabilizer, an antioxidant, or a combination thereof.

14. The light-shielding article according to any one of claims 1 to 3, wherein the plurality of alternating first and second polymer optical layers collectively reflect, on average, at least 70, 80, 90, or 95 percent of incident infrared light over a reflection bandwidth of at least 30 nanometers in the wavelength range of 700 nm to 1600 nm and / or 700 nm to 2000 nm at at least one incident light angle of 0°, 15°, 30°, 45°, 60°, or 75°.

15. An electromagnetic receiver and / or emitter comprising a light-shielding article according to any one of claims 1 to 3, attached to at least a portion of the electromagnetic receiver and / or emitter.

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