Structured transfer articles and articles, and methods for making structured articles

Abstract

Structured transfer articles and articles are provided. The transfer article includes a microstructured film having a plurality of microstructures protruding therefrom. The transfer article further includes a metallic or doped semiconductor release layer disposed on the microstructures, a (co)polymer layer disposed on the opposite side of the release layer from the microstructured film, and, optionally, a multilayer optical film disposed on the opposite side of the (co)polymer layer from the release layer. The multilayer optical film is composed of one or more alternating first and second inorganic optical layers that cooperate to reflect and absorb light incident perpendicularly to a first major surface of the microstructured film, and reflect and absorb an average of 50% or more of incident ultraviolet light over a wavelength reflection band of at least 30 nanometers in the wavelength range of 190 nanometers (nm) to 400 nm. The article includes at least a microstructured film, a multilayer optical film on the microstructures, and a (co)polymer layer disposed on the major surface of the multilayer optical film opposite the microstructured film. The present invention also provides a method for manufacturing an article, the method comprising the steps of providing a transfer article, applying a polymeric or crosslinkable material onto an outer surface of the transfer article, curing the material, and removing the release layer.

Description

[Background technology]

[0001] There is a type of communications network whose infrastructure is provided by a constellation of thousands of small satellites placed in low Earth orbit. These satellites require power from solar arrays mounted on frames, which require protection from the harsh environment of low Earth orbit.

[0002] Instruments typically operate at altitudes between 20 and 2000 km, where the thin atmosphere provides little absorption of solar radiation. Therefore, instruments operating at high altitudes are exposed to a more intense AM0 solar spectrum and higher intensities of ultraviolet (UV) radiation, especially UV-C radiation, compared to the AM1.5 solar spectrum encountered at Earth's surface. Summary of the Invention

[0003] In a first embodiment, a transfer article is provided. The transfer article includes a microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom. At least some of the microstructures each have an inclined surface, such that light incident perpendicularly on the first major surface of the microstructured film is blocked by the first major surface or the surface of at least one other microstructure after reflection. The transfer article further includes a release layer disposed on the plurality of microstructures, the release layer including a metal layer or a doped semiconductor layer. The transfer article further includes a (co)polymer layer disposed on the major surface of the release layer opposite the microstructured film, and a multilayer optical film disposed on the major surface of the (co)polymer layer opposite the release layer. The multilayer optical film is composed of one or more alternating first and second inorganic optical layers that cooperate to reflect and absorb light incident normally to the first major surface of the microstructured film, and reflect and absorb an average of 50, 60, 70, 80, 90, or 95% or more of incident ultraviolet light over a wavelength reflection band of at least 30 nanometers in the wavelength range of 190 nanometers (nm) to 400 nm.

[0004] In a second embodiment, another transfer article is provided. The transfer article includes a microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom. At least some of the microstructures each have an inclined surface, such that light incident perpendicularly on the first major surface of the microstructured film is blocked by the first major surface or the surface of at least one other microstructure after reflection. The transfer article further includes a release layer disposed on the plurality of microstructures, the release layer including a metal layer or a doped semiconductor layer. The transfer article also includes a (co)polymer layer disposed on the major surface of the release layer opposite the microstructured film, the (co)polymer layer optionally further including an ultraviolet absorber, a hindered amine light stabilizer, an antioxidant, or a combination thereof.

[0005] In a third aspect, an article is provided. The article includes a first microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom. At least some of the plurality of microstructures each have an inclined surface, the inclination causing light incident perpendicularly to the first major surface of the first microstructured film to be blocked by the first major surface or the surface of at least one other microstructure after reflection. The article further includes a release layer disposed on the plurality of microstructures, the release layer including a metal layer or a doped semiconductor layer. The article further includes a (co)polymer layer disposed on the major surface of the release layer opposite the first microstructured film, a multilayer optical film disposed on the major surface of the (co)polymer layer opposite the release layer, and a second microstructured film adjacent to the major surface of the multilayer optical film opposite the (co)polymer layer. The second microstructured film has a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom, at least some of the plurality of microstructures each having a sloped surface that causes light incident perpendicularly to the first major surface of the second microstructured film to be blocked after reflection at the first major surface or at least one other microstructure surface. The multilayer optical film is comprised of one or more alternating first and second inorganic optical layers that cooperate to reflect and absorb light incident perpendicularly to the first major surface of the second microstructured film, and to reflect and absorb an average of 50, 60, 70, 80, 90, or 95% or more of incident ultraviolet light in the wavelength range of 190 nanometers (nm) to 400 nm over a wavelength reflection band of at least 30 nanometers.

[0006] In a fourth embodiment, another article is provided. The article includes a microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom. At least some of the plurality of microstructures each have an inclined surface, the inclination causing light incident perpendicularly to the first major surface of the microstructured film to be blocked by the first major surface or a surface of at least one other microstructure after reflection. The article further includes a multilayer optical film disposed over the plurality of microstructures and a (co)polymer layer disposed on the major surface of the multilayer optical film opposite the microstructured film. The multilayer optical film is composed of one or more alternating first and second inorganic optical layers that cooperate to reflect and absorb light incident normally to the first major surface of the microstructured film, and reflect and absorb an average of 50, 60, 70, 80, 90, or 95% or more of incident ultraviolet light over a wavelength reflection band of at least 30 nanometers in the wavelength range of 190 nanometers (nm) to 400 nm.

[0007] In a fifth aspect, a method for manufacturing an article is provided. The method includes obtaining a transfer article according to the first or second aspect, applying a polymeric or crosslinkable material to an outer major surface opposite the first microstructured film, curing the polymeric or crosslinkable material to form a second microstructured film, and removing the release layer from the transfer article. The second microstructured film has a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom, at least some of the plurality of microstructures each having an inclined surface, the inclination causing light incident perpendicular to the first major surface of the second microstructured film to be blocked by the first major surface or the surface of at least one other microstructure after reflection. The first major surface of the second microstructured film is adjacent to a multilayer optical film.

[0008] Broadband UV protection is a technology area of ​​particular interest. While it has been shown that UV blocking can be achieved by alternating layers of high and low refractive index materials, these are often limited to a relatively narrow reflection band. On the other hand, UV absorbers cannot provide sufficient absorption without thick layers, and many solutions rely on organic absorbers, which are not necessarily resistant to the high-energy UV-C light and atomic oxygen present in low Earth orbit.

[0009] Substrates that are suitable for deposition of material layers with UV blocking properties are not suitable for use in space environments due to material property limitations, such as thermal expansion coefficient, radiation resistance, etc. If the material properties of substrates for use in space environments could be decoupled from those of substrates for use in article manufacturing (e.g., using vapor deposition coatings), a combination of higher performance and durability would be possible.

[0010] Transfer articles and articles according to at least certain embodiments herein provide an inorganic-based solution that combines the UV absorption of inorganic materials (e.g., titanium oxide or niobium oxide) with the reflection bands of alternating high and low refractive index materials. This results in a broadband UV blocking filter that is resistant to both UV and atomic oxygen. This technology has the potential to replace cover glass, an existing protection solution for space solar cells. The use of cover glass is expensive due to the fragility of glass slides and the need for extensive trimming and lamination of small glass slides.

[0011] Exemplary embodiments of the present disclosure provide various unexpected effects and advantages. For example, one advantage of exemplary embodiments of the present disclosure is that the combination of UV absorption and reflection in a structured article enables broadband UV blocking filters made of inorganic materials that are durable enough to withstand the low-Earth orbit environment. Additionally, the use of microstructured films has the advantage of minimizing light loss due to reflection, thereby improving the light collection efficiency of the article compared to flat films. Furthermore, it has been discovered that microstructured articles can be transferred to other microstructured substrates. The UV blocking layer can be formed by sputtering or vapor deposition in a roll-to-roll process. Therefore, a further advantage of exemplary embodiments is that they enable high-speed, roll-to-roll continuous production processes for the structured transfer articles and structured articles of the present disclosure.

[0012] Various aspects and advantages of exemplary embodiments of the present disclosure have been outlined above. The above summary is not intended to describe every embodiment or every configuration of the present disclosure. The following drawings and detailed description more particularly illustrate certain preferred embodiments utilizing the principles of the present disclosure. [Brief explanation of the drawings]

[0013] The present disclosure may be more fully understood from a consideration of the following detailed description of various embodiments of the disclosure in conjunction with the accompanying drawings, in which:

[0014] [Figure 1A] FIG. 1 is a perspective view of a Cartesian coordinate system of surfaces that can be used to describe various microstructured surfaces.

[0015] [Figure 1B] 1A-1C are schematic cross-sectional views of exemplary transfer articles and microstructured films used in the articles disclosed herein.

[0016] [Figure 1C]1A-1C are schematic cross-sectional views of exemplary structured transfer articles according to various exemplary embodiments disclosed herein.

[0017] [Figure 1D] 1 is a schematic cross-sectional view of an exemplary structured article according to various exemplary embodiments disclosed herein.

[0018] [Figure 2] 1A-1C are schematic cross-sectional views of exemplary structured transfer articles 10 and 20, and exemplary articles 30 and 40, according to various exemplary embodiments disclosed herein.

[0019] [Figure 3] FIG. 1 is a perspective view of a microstructured surface comprising a linear array of prisms.

[0020] [Figure 4A] FIG. 1 is a perspective view of a microstructured surface including an array of cube corner elements.

[0021] [Figure 4B] FIG. 1 is a perspective view of a microstructured surface including an array of pyramidal elements.

[0022] [Figure 5] FIG. 1 is a perspective view of a microstructured surface including an array of pyramids.

[0023] [Figure 6] FIG. 1 is a perspective view of a microstructured surface consisting of a diffraction grating with a bias angle.

[0024] [Figure 7] FIG. 1 is a perspective view of a microstructured surface comprising an array of inverted pyramids.

[0025] [Figure 8] 1 is a scanning electron microscope (SEM) image of a microstructured surface containing an array of inverted pyramids.

[0026] Like reference numerals refer to like elements throughout the drawings. The above drawings, which may not be drawn to scale, illustrate various embodiments of the present disclosure. Other embodiments are contemplated, as disclosed in the detailed description below. In all cases, this specification describes the present disclosure using illustrative embodiments and is not intended to be limiting. It should be understood that numerous other modifications and embodiments may be devised by those skilled in the art and are within the spirit and scope of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0027] The definitions in the following glossary of definitions apply throughout this application, unless a different definition is given in the claims or elsewhere in this specification.

[0028] [Glossary] Certain terms used in the specification and claims, while generally known, may require some explanation. The following explanations should be understood:

[0029] The term "fluoropolymer" means an organic polymer that contains fluorine.

[0030] "Nonfluorinated" means not containing fluorine.

[0031] The term "(co)polymer" or "(co)polymers" includes both homo(co)polymers and (co)polymers, as well as homo(co)polymers or (co)polymers formed by miscible blending (e.g., by coextrusion or by reaction (e.g., transesterification)). "(Co)polymer" includes random, block, and star (co)polymers.

[0032] As used herein, "adjacent" includes both direct contact (i.e., directly adjacent) and having one or more intermediate layers between the adjacent materials.

[0033] As used herein, "incident" refers to light falling on or striking a substance.

[0034] A "crosslinked" (co)polymer refers to a polymer in which the (co)polymer chains are covalently linked, usually via a crosslinking molecule or group, to form a (co)polymer network. Crosslinked (co)polymers are generally characterized by insolubility, although they may swell in the presence of an appropriate solvent.

[0035] The term "cure" includes cooling and / or solidification and also encompasses processes that cause chemical changes (e.g., crosslinking or other reactions that create covalent bonds that solidify or increase the viscosity of a multilayer film layer).

[0036] The term "cured (co)polymer" includes both crosslinked and non-crosslinked (co)polymers.

[0037] The term "metal" includes pure metals or metal alloys.

[0038] The term "film" or "layer" refers to a single stratum in a multilayer film.

[0039] The term "substrate" encompasses films and layers, including microstructured films / layers.

[0040] The terms "(meth)acrylic" or "(meth)acrylate" when used with respect to a monomer, oligomer, (co)polymer, or compound means an alkyl ester with a vinyl functionality that is the reaction product of an alcohol with acrylic or methacrylic acid.

[0041] The term "optically clear" refers to an article that has no visible distortion, haze, or defects when viewed with the naked eye from a distance of about 1 meter, preferably about 0.5 meters.

[0042] The term "optical thickness" when used with respect to a layer refers to the physical thickness of the layer multiplied by the in-plane index of refraction of that layer.

[0043] The terms "vapor coating" or "vapor depositing" refer to the application of a coating to a substrate surface from the vapor phase, for example, by evaporating a coating precursor material or the coating material itself and depositing it on the substrate surface. Exemplary vapor deposition coating processes include physical vapor deposition (PVD), chemical vapor deposition (CVD), and combinations thereof.

[0044] Orientational terms such as "atop," "on," "over," "covering," "uppermost," and "underlying" are used herein to describe the location of various elements in the coated articles to indicate the relative position of the element to the substrate, which is horizontally oriented and has its surface facing upward. However, unless expressly stated, this does not imply that the substrate or article must have any particular orientation in space during or after manufacture, or for purposes of interpretation of the claims.

[0045] As used herein, "radiation" refers to electromagnetic radiation, unless otherwise specified.

[0046] As used herein, "scattering" with respect to wavelengths of light means that the light deviates from its direct path and travels in different directions and with different intensities.

[0047] As used herein, "reflectance" is a measure of the proportion of light or other radiation that strikes a surface at normal incidence and is reflected therefrom. Reflectance typically varies with wavelength and is reported as the percentage of incident light reflected from the surface (0% - no light reflected, 100% - all light reflected). "Reflectivity" and "reflectance" are used interchangeably herein.

[0048] As used herein, "reflective" and "reflectivity" refer to the property of reflecting light or radiation, and in particular to reflectivity measured independently of the thickness of a material.

[0049] As used herein, "average reflectance" refers to reflectance averaged over a particular wavelength range.

[0050] As used herein, "absorption" means that a material converts the energy of optical radiation into internal energy.

[0051] As used herein, "absorb" in reference to a wavelength of light includes both absorption and scattering, since scattered light is ultimately absorbed. Absorbance can be measured using the method described in ASTM E903-12, "Standard Test Method for Solar Absorbance, Reflectance, and Transmittance of Materials Using an Integrating Sphere." The absorbance measurements described herein were performed by measuring transmittance as described above and then calculating absorbance using the formula [1].

[0052] As used herein, the term "absorbance" in reference to quantitative measurements refers to the common logarithm to the base 10 of the ratio of the radiant energy incident on a material to the radiant energy transmitted through the material. The ratio can be expressed as the radiant flux incident on the material divided by the radiant flux transmitted through the material. Absorbance (A) can be calculated based on the internal transmittance (T) as follows:

number

[0053] Emissivity can be measured using an infrared imaging radiometer according to the method described in ASTM E1933-14 (2018) "Standard Practice for Measuring and Correcting Emissivity Using an Infrared Imaging Radiometer." According to Kirchhoff's law of thermal radiation, absorbance correlates with emissivity. In this specification, absorbance, absorptivity, emissivity, and emittance are all used synonymously for the purpose of emitting infrared energy into the atmosphere. Absorb and emit are also used synonymously.

[0054] As used herein, the terms "transmittance" and "transmission" refer to the ratio of light incident on the material to the total amount transmitted through a layer of material, which may include effects such as absorption, scattering, and reflection. Transmittance (T) ranges from 0 to 1 or is expressed as a percentage (T%).

[0055] As used herein, the term "transparent" refers to a material (for example, a film or layer) that absorbs less than 20% of light having a wavelength between 350 nm and 2500 nm.

[0056] As used herein, "bandwidth" refers to the width of a band of contiguous wavelengths.

[0057] As used herein, "flexible" means capable of being wound around a roll core with a radius of curvature of at most about 7.6 centimeters (cm) (3 inches), and in some embodiments, a radius of curvature of at most about 6.4 cm (2.5 inches), 5 cm (2 inches), 3.8 cm (1.5 inches), or 2.5 cm (1 inch). In some embodiments, the flexible member is capable of being wound around a radius of curvature of at least about 0.635 cm (1 / 4 inch), 1.3 cm (1 / 2 inch), or 1.9 cm (3 / 4 inch).

[0058] As used herein, "about" or "approximately" when used in connection with a numerical value or shape means ±5% of that numerical value, property or characteristic, but expressly includes the numerical value itself.

[0059] As used herein, "substantially" means that a property or characteristic is exhibited to a greater extent than the opposite property or characteristic. For example, a "substantially" transparent substrate refers to a substrate that transmits more radiation (e.g., visible light) than a non-transmitting (i.e., absorbing and reflecting) substrate. 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.

[0060] As used herein and in the accompanying embodiments, the singular forms "a," "an," and "the" include the plural reference unless the context clearly dictates otherwise. Thus, for example, reference to a microfiber containing a "compound" includes a mixture of two or more compounds. Also, as used herein and in the accompanying embodiments, "or" is used to mean "and / or" unless the context clearly dictates otherwise.

[0061] Unless otherwise indicated, all numerical values ​​expressing quantities, components, measurements of physical properties, and the like in the specification and embodiments are understood to be modified by the word "about." Accordingly, unless expressly indicated otherwise, the numerical parameters set forth in the specification and accompanying embodiments may vary depending on the desired properties sought to be obtained by those of ordinary skill in the art having access to the teachings of the present disclosure. At the very least, and not intended to limit the scope of equivalents to the embodiments recited in the claims, each numerical parameter should be construed in light of the number of reported significant digits and ordinary rounding techniques.

[0062] By definition, the sum of the weight percentages of all components in a composition equals 100% by weight.

[0063] Various exemplary embodiments of the present disclosure are described below. The exemplary embodiments of the present disclosure may undergo various changes and modifications 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 defined by the claims and their equivalents.

[0064] Referring to FIG. 1A, the microstructured surface can be characterized in three-dimensional space by superimposing a Cartesian coordinate system on the structure. A first reference plane 124 is centered between major surfaces 112 and 114. The first reference plane 124 is defined as the yz-plane and has the x-axis as its normal vector. A second reference plane 126 is defined as the xy-plane, extends approximately coplanar with surface 116, and has the z-axis as its normal vector. A third reference plane 128 is defined as the xz-plane, is centered between first end surface 120 and second end surface 122, and has the y-axis as its normal vector.

[0065] In some embodiments, the microstructured surface is three-dimensional at the macroscale. However, at the microscale (e.g., a surface region including two adjacent microstructures and a valley or groove disposed therebetween), the base layer / base member can be considered flat relative to the microstructures. The width and length of the microstructures lie in the xy plane, and the height lies in the z direction. Furthermore, the base layer is parallel to the xy plane and perpendicular to the z plane.

[0066] [Transfer items] In a first aspect, a transfer article is provided, the transfer article comprising:

[0067] a microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom, at least a portion of the plurality of microstructures each having a surface with a slope that causes light incident perpendicular to the first major surface of the microstructured film to be blocked, after reflection, by the first major surface or the surface of at least one other microstructure;

[0068] a release layer disposed over the plurality of microstructures, the release layer including a metal layer or a doped semiconductor layer;

[0069] a (co)polymer layer disposed on a major surface of the release layer opposite the microstructured film;

[0070] A multilayer optical film disposed on a major surface of the (co)polymer layer opposite the release layer, the multilayer optical film being comprised of one or more alternating first and second inorganic optical layers that cooperate to reflect and absorb light incident normal to the first major surface of the microstructured film, and to reflect and absorb an average of 50, 60, 70, 80, 90, or 95% or more of incident ultraviolet light over a wavelength reflection band of at least 30 nanometers in the wavelength range of 190 nanometers (nm) to 400 nm.

[0071] In a second aspect, another transfer article is provided, the transfer article comprising:

[0072] a microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom, at least a portion of the plurality of microstructures each having a surface with a slope that causes light incident perpendicular to the first major surface of the microstructured film to be blocked, after reflection, by the first major surface or the surface of at least one other microstructure;

[0073] a release layer disposed over the plurality of microstructures, the release layer including a metal layer or a doped semiconductor layer;

[0074] A (co)polymer layer disposed on a major surface of the release layer opposite the microstructured film, the (co)polymer layer further comprising an ultraviolet absorber, a hindered amine light stabilizer, an antioxidant, or a combination thereof.

[0075] The following disclosure relates to both the first and second aspects.

[0076] Referring again to FIG. 1A, "light incident normal to the first major surface of the microstructured film" means light incident on the first major surface 116 of the microstructured film from a direction perpendicular to reference plane 126 (and parallel to reference plane 124).

[0077] 1B, a schematic cross-sectional view of a microstructured film 100 including a plurality of microstructures 140 suitable for exemplary transfer articles and articles of the present disclosure is shown. The phrase "microstructures having a surface with a slope that causes light incident perpendicularly to the first major surface of the microstructured film to be blocked by the first major surface of the microstructured film or the surface of at least one other microstructure" means that incident light ("I") is incident on the surface of microstructure 140a perpendicularly to first major surface 130 of microstructured film 100, and microstructure 140a has a slope 142 that causes reflected light ("R") to be blocked by the first major surface of the microstructured film (not shown) or the surface of another microstructure 140b. In this case, a valley (e.g., bottom) 147 between two adjacent microstructures 140a and 140b can be part of the first major surface where the reflected light is blocked if the reflected light is not blocked by the surface of microstructure 140b. 1A, the first major surface 130 of the microstructured film 100 is considered parallel to the second major surface 110 of the microstructured film 100. The slope (e.g., sloping surface) 142 of the microstructure 140a is the height 141 of the microstructure 140a divided by the width 143 between the peak (e.g., the higher end of the sloping surface) 145 and the base (e.g., the lower end of the sloping surface) 147. Another way to determine the slope is using the following formula:

number

[0078] 1C is a schematic cross-sectional view of a portion of an exemplary transfer article 10 according to at least some exemplary embodiments of the present disclosure. The structured transfer article 10 includes a microstructured film 18 having a first major surface 21 and an opposite second major surface 23. The first major surface 21 includes a plurality of microstructures 45 protruding therefrom. The transfer article 10 includes a release layer 16 disposed on the plurality of microstructures 45. The release layer 16 is described below. The transfer article 10 further includes a (co)polymer layer 15 disposed on the major surface of the release layer 16 opposite the microstructured film 18, and a multilayer optical film 5 disposed on the major surface of the (co)polymer layer 15 opposite the release layer 16. The multilayer optical film 5 includes alternating first inorganic optical layers 12 and second inorganic optical layers 13.

[0079] Referring to Figure 2, the present disclosure describes structured transfer articles 10 and 20. Both transfer articles 10 and 20 include a microstructured film 18 having a first major surface 21 and a second major surface 23, a release layer 16 disposed on first major surface 21 (e.g., on the plurality of microstructures of the microstructured film), and a (co)polymer layer 15 disposed on a major surface 27 of release layer 16 opposite microstructured film 18. For simplicity, the microstructures are not shown in the schematic illustration of the various components in this figure. Optionally, (co)polymer layer 15 may be a first (co)polymer layer, in which case transfer article (10 or 20) further includes a second (co)polymer layer 17 disposed between microstructured film 18 and release layer 16.

[0080] Transfer article 10 also includes a multilayer optical film 5 disposed on a major surface 29 of (eg, first) (co)polymer layer 15 .

[0081] Multilayer optical film 20 includes one or more alternating first inorganic optical layers 12(AN) and second inorganic optical layers 13(AN).

[0082] [Microstructured film] As described above, the microstructured film has a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom, at least some of the plurality of microstructures each having a surface with a slope such that light incident perpendicularly on the first major surface of the microstructured film is blocked by the first major surface or the surface of at least one other microstructure after reflection. Therefore, a variety of different shapes of microstructures are suitable. For example, in some cases, the microstructures have the shape of a prism, pyramid, inverted pyramid, diffraction grating, inverted cone, or cone. Such shapes are described below. Additionally, inverted versions of these shapes are also suitable. The three-dimensional shape can have any number of facets (e.g., square, pentagonal, or hexagonal pyramids are all suitable).

[0083] In certain embodiments, each microstructure has the same size and shape, which facilitates consistent optical performance of the multilayer optical film deposited on the microstructure across the entire surface of the structured article. In certain embodiments, the surfaces having a slope that causes light incident perpendicularly to the first major surface of the microstructured film to be blocked by the first major surface or at least one other microstructure surface after reflection each have the same slope. In this case, the microstructures do not need to have the same size or shape, as long as they have the same slope.

[0084] In some cases, at least some of the microstructures have a triangular cross-sectional shape, such as microstructures 140 and 40 shown in Figures 1B and 1C, respectively. Although not required, in some cases, at least some of the microstructures 140 include at least one sloping sidewall (e.g., 142) that results in pointed peaks 145. Advantageously, it has been found that it is possible to form a multilayer optical film on microstructures having pointed peaks (e.g., non-rounded peaks) without producing "pinholes" due to insufficient deposition of the multilayer optical film at the apex of the peaks.

[0085] 1B, at least some microstructures 140 include at least one sloping sidewall (e.g., 142) having a peak angle (e.g., apex angle) theta (θ) of 90 degrees or less, 85 degrees, 80 degrees, 75 degrees, 70 degrees, 65 degrees, 60 degrees, 55 degrees, 50 degrees, or 45 degrees or less, and 5 degrees or more, 7 degrees, 10 degrees, 12 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, or 50 degrees or more. As used herein, "peak angle" refers to the angle between opposing side surfaces at the apex of the microstructure.

[0086] In some cases, the aspect ratio of the height H to the (total) width W (i.e., H:W) of the multiple microstructures 140 may be 10:1 or less, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, or 1:1 or less, and 1:2 or more.

[0087] Typically, each microstructure is 0.5 micrometers or larger, 1 micrometer, 2 micrometers, 3 micrometers, 4 micrometers, 5 micrometers, 6 micrometers, 7 micrometers, 8 micrometers, 9 micrometers, 10 micrometers, 12 micrometers, 15 micrometers, 17 micrometers, 20 micrometers, 25 micrometers, 30 micrometers, 35 micrometers, 40 micrometers, 45 micrometers, 50 micrometers, 60 micrometers, 70 micrometers, 80 micrometers, 90 micrometers, 100 micrometers, 110 micrometers, 120 micrometers, 150 micrometers, 160 micrometers, 170 micrometers, 180 micrometers, 190 micrometers, 200 micrometers, 210 micrometers, 220 micrometers, 230 micrometers, 240 micrometers, 250 micrometers, 260 micrometers, 270 micrometers, 280 micrometers, 290 micrometers, 300 micrometers, 310 micrometers, 320 micrometers, 330 micrometers, 340 micrometers, 350 micrometers, 360 micrometers, 370 micrometers, 380 micrometers, 390 micrometers, 400 micrometers, 410 micrometers, 420 micrometers, 430 micrometers, 440 micrometers, 450 micrometers, 460 micrometers, 470 micrometers, 480 micrometers, 490 micrometers, 500 micrometers, 510 micrometers, 520 micrometers, 530 micrometers, micrometers, 175 micrometers, 200 micrometers, 225 micrometers, or 250 micrometers or more, and may be 500 micrometers or less, 475 micrometers, 450 micrometers, 425 micrometers, 400 micrometers, 375 micrometers, 350 micrometers, 325 micrometers, 300 micrometers, 275 micrometers, 250 micrometers, 225 micrometers, 200 micrometers, 175 micrometers, 150 micrometers, 125 micrometers, 100 micrometers, 75 micrometers, 50 micrometers, or 25 micrometers or less.

[0088] Referring to FIG. 3 , in one embodiment, the first major surface 300 of the microstructured film 100 includes a linear array of regular right prisms 320. Each prism has a first facet (e.g., an inclined surface) 321 and a second facet 322. The prisms are shown formed on a substrate member 310, which has a first plane 331 (parallel to the reference plane 126) on which the prisms are formed and a substantially flat or planar second surface 332 opposite the first plane. The second surface 332 may be structured. By right prism, we mean that the peak angle θ (340) is typically about 90 degrees, although this angle can vary within the ranges discussed above. The peaks may be acute (as shown) or rounded. The spacing between the peaks (of the prisms) is characterized as the pitch (“P”). In this embodiment, the pitch is also equal to the maximum width of the valleys. The pitch can be greater than 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 microns, and can be up to 250 microns. The length ("L") of the (e.g., prismatic) microstructures is typically the largest dimension and can span the entire length of the microstructured surface. In selected cases, the linear prismatic columns are oriented to extend across the width of the microstructured surface (e.g., crossweb) rather than along the length of the microstructured surface (e.g., downweb).

[0089] In another embodiment, the first major surface of the microstructured film may have the same surface geometry as cube corner retroreflective sheeting. Referring to Figure 4A, cube corner retroreflective sheeting includes a thin, transparent layer having a substantially flat surface and an opposing structured surface 410 containing a plurality of cube corner elements 417. The microstructured surface 410 in Figure 4A can be characterized as an array of cube corner elements 417 defined by three sets of parallel grooves (i.e., valleys) 411, 412, and 413, where two sets of grooves (valleys) intersect with each other at angles greater than 60 degrees, and the third set of grooves (valleys) intersects with the other two sets at angles less than 60 degrees, forming pairs of tilted cube corner elements (see U.S. Pat. No. 4,588,258 (Hoopman)). The groove angles are selected so that the dihedral angles formed at the groove intersections (e.g., 414, 415, and 416 of a representative cube corner element 417) are approximately 90 degrees. In some embodiments, the triangular base has an angle of at least 64 degrees, 65 degrees, 66 degrees, 67 degrees, 68 degrees, 69 degrees, or 70 degrees, with other angles being 55 degrees, 56 degrees, 57 degrees, or 58 degrees.

[0090] In another embodiment, as shown in Figure 4B, the first major surface of the microstructured film 400 can be characterized as an array of pyramidal peak structures 420 defined by a first set of parallel grooves (valleys) in the y-direction and a second set of parallel grooves in the x-direction. The bases of the pyramidal peak structures are polygonal, typically square or rectangular, depending on the groove spacing. The peak angle θ (440) is typically about 90 degrees, although this angle can vary within the ranges discussed above.

[0091] In some cases, the microstructures may have a pyramidal shape. Referring to Figure 5, the microstructured surface 500 of the microstructured film includes an array of pyramids 540. Each pyramidal-shaped microstructure typically has only one sloping sidewall 542. The peak 545 of each pyramid may be pointed or rounded.

[0092] 6 shows a schematic diagram of a first major surface 600 of a microstructured film including a diffraction grating with a bias angle. A second major surface 610 of the microstructured film defines a longitudinal axis ("LA") along its length, and a plurality of microstructures 640 extend laterally across the first major surface 600 to define a major axis ("A"). A bias angle ("B") is defined between the major axis A and the longitudinal axis LA. In some embodiments, the bias angle B is in the range of about 0 degrees to about 90 degrees, for example, in the range of about 20 degrees to about 70 degrees.

[0093] In another embodiment, as shown in FIG. 7 , the first major surface 710 of the microstructured film 700 may be characterized as an array of inverted pyramid structures 720. The structures 720 include facets 722 that meet at valleys (e.g., inverted peaks) 721, with the opposite edges 724 of each facet joining to form the base of the pyramid structure 720 (i.e., the outermost surface of the microstructured film 700). The pyramid base is a polygon, such as a square or a rectangle. In this particular embodiment, adjacent columns (e.g., end column 762 and adjacent column 764) are offset from one another, such that the bottoms of the valleys of adjacent structures (e.g., 723 of column 762 and adjacent structure 725 of column 764) are at different locations along the length of the columns (e.g., in the y-axis direction). It is expressly contemplated that such an offset configuration may be applied to any of the microstructures disclosed herein.

[0094] 8, the first major surface 810 of the microstructured film 800 may be characterized as an array of inverted pyramids 820. The pyramid structures 820 include curved walls 822 that terminate in valleys (e.g., inverted peaks) 821, with edges 824 of the walls 822 opposite the valleys 821 coming together to form the bases of the pyramid structures 820 (i.e., the outermost surface of the microstructured film 800). The bases of the pyramids may be polygonal, such as hexagonal, pentagonal, square, rectangular, triangular, or circular or elliptical.

[0095] In some cases, the microstructured film is flexible (as defined in the glossary). An advantage of using a flexible microstructured film is that it avoids the high cost of handling rigid glass, especially small pieces of glass, which can break during handling and require significant labor due to the need to apply multiple pieces of glass. Furthermore, in some embodiments according to the present disclosure, flexible microstructured films are used in roll-to-roll processing for the manufacture of structured and transfer articles. An advantage of roll-to-roll manufacturing is that structured and transfer articles can be manufactured in large area formats. In some cases, the microstructured film (or article / transfer article) has an area of ​​at least 50 square centimeters, e.g., at least 60, 70, 80, 90, 100, 1,000, or at least 10,000 square centimeters.

[0096] In any of the above-described embodiments, the microstructured film may comprise or be composed of a polymeric material such as a (co)polymer. In some exemplary embodiments, the microstructured film comprises polyethylene terephthalate (PET), cured polysiloxane, silicone-based thermoplastic polymer, cured urethane, thermoplastic urethane, cured (meth)acrylate, cured epoxy, cured vinyl ether, cured oxetane, cured thiol-acrylate, cured thiol-ene, polypropylene, polyethylene, polymethyl methacrylate (PMMA), coPMMA, polyimide, cyclic olefin copolymer, cyclic olefin polymer, polycarbonate, polyethylene naphthalate (PEN), or a fluoropolymer (co)polymer comprising polymerized units derived from one or more monomers selected from tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, perfluoroalkoxyalkylene, or vinyl fluoride, or a combination thereof. Optionally, the cured polymeric material may be crosslinked.

[0097] Suitable polyimides are available from EI DuPont de Nemours (Wilmington, Delaware) under the trade name "KAPTON," with "KAPTON CS100" being currently preferred. Suitable PMMA polymers include CP71 and CP80 available from Ineos Acrylics, Inc. (Wilmington, Delaware). Suitable crosslinkable silicones include those available from Dow Corning Corporation (Midland, Michigan) under the trade name "DOW CORNING 93-500 SPACE GRADE ENCAPSULANT KIT." Suitable polycarbonates include those available from Bayer AG (Darmstadt, Germany) under the trade name "Makrofol." Suitable methyl methacrylate copolymers (CoPMMA) include, for example, CoPMMA made from 75% by weight methyl methacrylate (MMA) and 25% by weight ethyl acrylate (EA) monomers (available from Ineos Acrylics, Inc., London, UK, under the trade name "PERSPEX CP63" or from Arkema Corp., Philadelphia, PA, under the trade name "ATOGLAS 510"); CoPMMA formed from copolymerized units of MMA and n-butyl methacrylate (nBMA); or a blend of PMMA and poly(vinylidene fluoride) (PVDF). A suitable polyethylene naphthalate (PEN) polymer is available from DuPont Teijin, Chester, VA, under the trade name "Teonex Q51."

[0098] In certain exemplary embodiments, preferred fluorinated (co)polymers include tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, perfluoroalkoxyalkanes, or combinations thereof. Suitable fluoropolymers are available from EI DuPont de Nemours (Wilmington, Delaware) under the trade designation "TEFLON FEP100," of which "TEFLON FEP100 500A" is currently preferred. Suitable exemplary fluoropolymers include copolymers of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride (THV), available from Dyneon LLC (Oakdale, Minnesota) 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."

[0099] In some applications, for example, when an article is exposed to large fluctuations in environmental temperature, it may be useful to use a film with a low coefficient of thermal expansion (CTE). Exemplary low-CTE polymers include, but are not limited to, polyimide, heat-stabilized PEN, and PET. Preferably, the low-CTE material has a CTE of 80 ppm / K (parts per million per kelvin) or less, 70 ppm / K, 60 ppm / K, 50 ppm / K, 40 ppm / K, 30 ppm / K, or 25 ppm / K or less. The coefficient of thermal expansion has the general meaning used in the art, i.e., as measured using ASTM E831.

[0100] The smoothness of the layer and its adhesion to the microstructured film can be improved by any suitable pretreatment of the microstructured film or by applying an optional primer layer. Surface modification methods are well known to those skilled in the art. In one embodiment, the pretreatment step includes discharge treatment of the substrate in a reactive or non-reactive atmosphere (e.g., plasma discharge, glow discharge, corona discharge, dielectric barrier discharge, or atmospheric discharge), chemical pretreatment, or flame pretreatment. These pretreatments are useful for making the surface of the microstructured film more receptive to subsequently applied layers. In one embodiment, the method may include plasma pretreatment. For organic surfaces, the plasma pretreatment may include nitrogen or water vapor. Another pretreatment step includes coating the microstructured film with an inorganic or organic basecoat layer, optionally followed by further pretreatment using plasma or other pretreatments as described above.

[0101] Preferably, the microstructured film itself transmits an average of 70% or more, 80% or more, 90% or more, or 95% or more of incident visible light in the wavelength range from greater than 400 nm to 700 nm.

[0102] [Peeling layer] The release layer may include a metal layer. The metal layer may include at least one selected from the group consisting of a single metal, a mixture of two or more metals, an intermetallic compound or alloy, a semimetal or metalloid, a metal oxide, a metal and mixed-metal oxide, a metal and mixed-metal fluoride, a metal and mixed-metal nitride, a metal and mixed-metal carbide, a metal and mixed-metal carbonitride, a metal and mixed-metal oxynitride, a metal and mixed-metal boride, a metal and mixed-metal oxyboride, a metal and mixed-metal silicide, a diamond-like carbon, a diamond-like glass, graphene, and combinations thereof. In some embodiments, the metal layer may be formed from Al, Zr, Cu, NiCr, Ti, or Nb. In certain embodiments, the release layer includes copper oxide. In certain embodiments, the release layer includes aluminum silicon oxide. A suitable thickness range for the release layer is 1 nm to 3000 nm.

[0103] Alternatively, the release layer may comprise a doped semiconductor layer. In some embodiments, the doped semiconductor layer may be formed of Si, B-doped Si, Al-doped Si, or P-doped Si, with a thickness of 1 nm to 3000 nm. A particularly suitable doped semiconductor layer is Al-doped Si, with a composition ratio of Al of 10%. Release layers can typically be prepared by evaporation, reactive evaporation, sputtering, reactive sputtering, chemical vapor deposition, plasma-enhanced chemical vapor deposition, and atomic layer deposition. Preferred methods include vacuum preparation methods such as sputtering and evaporation. In at least some embodiments according to the present disclosure, the transfer article exhibits a release value of 2 to 50 g / inch (g / in) between the release layer and the (e.g., first) (co)polymer layer. Such a release value allows for easy removal of the release layer when attempting to transfer the article to another substrate.

[0104] [(Co)polymer layer] Exemplary transfer articles include at least one (co)polymer layer. Referring to Figure 2, (co)polymer layer 15 is overlaid on first major surface 27 of release layer 16. Optionally, (co)polymer layer 15 may be the first (co)polymer layer, and transfer article (10 or 20) may further include second (co)polymer layer 17 overlaid on first major surface 21 of microstructured film 18. In certain embodiments, the (co)polymer layer is substantially transparent.

[0105] Each (co)polymer layer comprises a (co)polymer independently 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.

[0106] The (co)polymer layer can be formed from a variety of organic materials or compounds using a variety of methods. The (co)polymer layer may be crosslinked in situ after application. In one embodiment, the (co)polymer layer can be formed by flash evaporation, vapor deposition, and (co)polymerization of monomers, for example, using heat, plasma, UV radiation, or electron beam.

[0107] Exemplary monomers used in this method include volatile (meth)acrylate monomers. In certain embodiments, volatile acrylate monomers are used. Suitable (meth)acrylates have a molecular weight low enough to allow flash evaporation and a molecular weight high enough to allow condensation on a substrate. In addition, organic materials or compounds can be evaporated using any method, such as the method described in PCT Publication No. WO2022 / 243756 (Sweetnam et al.), which describes evaporation methods for metal alkoxides.

[0108] If desired, the (co)polymer layer may 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 may be crosslinked or (co)polymerized (as described above) if desired. The chemical composition and thickness of the desired layer depend in part on the nature of the article and the desired application. Coating efficiency can be improved by cooling the article.

[0109] 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, which 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, β-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 ... Examples of suitable vinyl compounds include acrylate, neopentyl glycol diacrylate, propoxylated neopentyl glycol diacrylate, polyethylene glycol diacrylate, tetraethylene glycol diacrylate, bisphenol A epoxy diacrylate, trimethylolpropane triacrylate, tricyclodecane dimethanol diacrylate, hydroxyl pivalate neopentyl glycol diacrylate, ethoxylated trimethylolpropane triacrylate, propylated trimethylolpropane triacrylate, tris(2-hydroxyethyl)-isocyanurate triacrylate, pentaerythritol triacrylate, phenylthioethyl acrylate, naphthyloxyethyl acrylate, IRR-214 cyclic diacrylate from UCB Chemicals, epoxy acrylate RDX80095 from Rad-Cure Corporation, the corresponding methacrylates of the above acrylates, and mixtures thereof. Exemplary vinyl compounds include vinyl ethers, styrene, vinyl naphthylene, and acrylonitrile. Exemplary alcohols include hexanediol, naphthalenediol, and hydroxyethyl methacrylate.Exemplary carboxylic acids include phthalic acid, terephthalic acid, and (meth)acrylic acid. Exemplary acid anhydrides include phthalic anhydride and glutaric anhydride. Exemplary acyl halides include hexanedioic acid dichloride and succinic acid dichloride. Exemplary thiols include ethylene glycol-bisthioglycolate and phenylthioethyl acrylate. Exemplary amines include ethylenediamine and hexane-1,6-diamine.

[0110] Optionally, at least one (co)polymer layer may further comprise an additive such as an ultraviolet absorber, a hindered amine light stabilizer, an antioxidant, or a combination thereof. In particular, in certain embodiments of the transfer article of the present disclosure, the (co)polymer layer and / or the microstructured film further comprise an additive such as an ultraviolet absorber, a hindered amine light stabilizer, an antioxidant, or a combination thereof. UV absorbers (UVA), hindered amine light stabilizers (HAL), and antioxidants help prevent photo-oxidative degradation of the (co)polymer layer. Suitable compounds include benzophenones, benzotriazoles, and triazines (e.g., benzotriazines). Exemplary UVA suitable for incorporation into the (co)polymer layer include those available from BASF Corporation (Florham Park, New Jersey) under the trade names "TINUVIN 1577" and "TINUVIN 1600." 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 compatible with PVDF fluoropolymers. Exemplary HALs suitable for incorporation include those available from BASF Corporation under the trademarks "CHIMASORB 944" and "TINUVIN 123." Typically, the UVA, HAL, and / or antioxidant are included in the (co)polymer layer at a concentration of 1 to 10 wt. %.

[0111] In certain embodiments, the (co)polymer layer is preferably crosslinked.

[0112] In some exemplary embodiments, the outer (co)polymer layer comprises an olefin-based (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)polymers, and blends thereof.

[0113] In certain exemplary embodiments, the (co)polymer layer further comprises an ultraviolet absorber, a hindered amine light stabilizer, an antioxidant, or a combination thereof.

[0114] Preferably, the UV absorber is selected from benzotriazole compounds, benzophenone compounds, triazine compounds, or combinations thereof. A currently preferred hindered amine light stabilizer is available from BASF USA (Florham Park, New Jersey) under the trade name "TINUVIN." Preferably, the hindered amine light stabilizer is 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." Preferably, antioxidants suitable for polyolefins are selected from IRGANOX 1010, IRGANOX 1076, IRGAFOS 168, or combinations thereof.

[0115] [Multilayer optical film] Referring again to FIG. 2, transfer article 10 includes a multilayer optical film 5 including one or more alternating first inorganic optical layers 12(A-N) and second inorganic optical layers 13(A-N) disposed on a first major surface 29, as described below.

[0116] The multilayer optical film typically has a thickness of 200 nm or more, 250 nm, 300 nm, 350 nm, 400 nm, 500 nm, or 550 nm or more, and 1500 nm or less, 1400 nm, 1300 nm, 1200 nm, 1100 nm, 1000 nm, 900 nm, 850 nm, 800 nm, 750 nm, 700 nm, 650 nm, or 600 nm or less, for example, a thickness of 200 nm to 1500 nm.

[0117] [Inorganic layer] 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, zinc aluminum oxide, or zinc oxide. As is well known, alloys of oxides may also be suitable. In some cases, the second optical layer comprises at least one of silicon oxide, aluminum silicon oxide, N-type or P-type doped silicon oxide, aluminum oxide, aluminum fluoride, magnesium fluoride, calcium fluoride, indium tin oxide, or zinc oxide. In selected embodiments, the first optical layer comprises at least one of niobium oxide or titanium oxide, and the second optical layer comprises aluminum silicon oxide. When a photoactive inorganic material such as titanium oxide is used, a non-photoactive material (e.g., silicon oxide, aluminum oxide, etc.) may typically be disposed between the photoactive inorganic material and any organic layers to minimize degradation of the organic layers. For example, referring again to FIG. 2, the layer of non-photoactive material can be an intermediate layer 19 located between first optical layers 12A and second microstructured film 11.

[0118] It has been unexpectedly discovered that wavelengths of light in the UVA, UVB, and UVC regions can be blocked from the microstructured film simply by combining the reflection and absorption of multiple alternating first and second inorganic optical layers, while generally maintaining an acceptable amount of transmission of visible light (e.g., at least 50% of the incident visible light).

[0119] Optical thin film stack designs, consisting of alternating thin layers of inorganic dielectric materials with refractive index contrast, are particularly suited to multilayer optical films. Recently, such thin film stacks have been used for applications in the UV, visible, near-infrared (NIR), and infrared (IR) spectral regions. Depending on the spectral region of interest, specific materials are suited to that region. These materials are coated using two forms of physical vapor deposition (PVD): evaporation or sputtering. Evaporation coating relies on heating the coating material (evaporant) to a temperature at which it evaporates. The vapor is then condensed onto a substrate. Electron beam evaporation is the most commonly used method for depositing dielectric mirror coatings. Sputtering coating involves bombarding the surface of a material (the "target") with energetic gas ions, ejecting atoms that condense on the nearby substrate. The coating method and its configuration significantly affect the thin film coating rate and structure-property relationships. Ideally, the coating speed should be high enough that both the process throughput and film performance are acceptable, which is characterized by a dense, low-stress, void-free, and optically non-absorbing coating layer.

[0120] The number of optical layers is selected to achieve the desired optical properties with the minimum number of layers, taking into account film thickness, flexibility, and economy. Those skilled in the art can extend such deposition techniques to CVD, ALD, and other deposition methods. Typically, the total number of layers is 21 or less, with 19, 17, 15, or 13 optical layers or less being preferred, and 3 or more optical layers, with 5, 7, 9, or 11 or more optical layers being preferred. In selected embodiments, the multilayer optical film is formed from at least one first optical layer and two second optical layers.

[0121] The thickness of each first optical layer and each second optical layer can vary substantially. For example, in some embodiments, each first optical layer and each second optical layer has a thickness of 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; and a thickness of 2000 nm or less, 500 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 certain embodiments, each first optical layer and each second optical layer independently has a thickness of 20 nm to 400 nm.

[0122] The multilayer optical films described herein can be manufactured using conventional processing techniques, such as those described in US Pat. No. 6,783,349 (Neavin et al.), the entire disclosure of which is incorporated herein by reference.

[0123] In the production of inorganic coatings, electron beam processes are best suited for coating discrete components. Optionally, for larger articles, articles or transfer articles can be produced in a continuous roll-to-roll (R2R) fashion. While some chambers have demonstrated R2R film coating, a layer-by-layer coating sequence is still required. For R2R sputtering of the inorganic layers of articles or transfer articles, it is advantageous to use a sputtering system with multiple sources arranged around one or two coating drums. Here, for a 13-layer optical stack design, a two-pass or single-pass machine process is feasible, coating alternating high- and low-index layers sequentially. The number of machine passes required depends on the machine design, cost, and the practicality of 13 continuous sources. Additionally, the coating speed will need to match the single-film line speed.

[0124] The film roll is started at a predetermined speed, then the sputtering source power is ramped up to full operating power, reactive gas is introduced, and a steady state is achieved. The process continues until a predetermined total length is reached, depending on the length of the film to be coated. Here, the sputtering source is perpendicular to the film being coated and wider than the film width, resulting in very high film thickness uniformity. Once the desired length of the coating film is reached, the reactive gas is turned off, and the target is sputtered to a pure metal surface state. The film's direction of travel is then reversed, and AC frequency (40 kHz) power is applied to the rotating pair of sputtering targets under an argon sputtering atmosphere. Once a steady state is reached, oxygen reactive gas is introduced to impart transparency and a low refractive index. Under the predetermined process conditions and line speed, a second layer is coated to the same length as the first layer. Again, because the sputtering source is perpendicular and wider than the film width, very high film thickness uniformity is achieved. Once the desired length of the coating film is reached, the reactive oxygen is removed, and the target is sputtered in argon to a pure metal surface state. Layers 3 through 5 (or 7, 9, 11, 13, etc.) are coated in this sequence depending on the optical target. Once complete, the film roll is removed for post-processing.

[0125] The transfer article can be subjected to various post-treatments, such as heat treatment, ultraviolet (UV) or vacuum ultraviolet (VUV) treatment, electron beam (e-beam) treatment, or plasma treatment. Heat treatment can be carried out by passing the article through an oven or by directly heating the article in the coating apparatus (e.g., using an infrared heater or directly heating on a drum). For example, heat treatment can be carried out at temperatures of about 30°C to about 200°C, about 35°C to about 150°C, or about 40°C to about 70°C.

[0126] [Goods] In a third aspect, an article is provided, the article comprising:

[0127] a first microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom, at least a portion of the plurality of microstructures each having a surface with a slope that causes light incident perpendicular to the first major surface of the first microstructured film to be blocked, after reflection, by the first major surface or the surface of at least one other microstructure;

[0128] a release layer disposed on the plurality of microstructures, the release layer comprising a metal layer or a doped semiconductor layer;

[0129] a (co)polymer layer disposed on a major surface of the release layer opposite the first microstructured film;

[0130] a multilayer optical film disposed on a major surface of the (co)polymer layer opposite the release layer;

[0131] A second microstructured film adjacent to the major surface of the multilayer optical film opposite the (co)polymer layer, the second microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom, at least some of the plurality of microstructures each having a surface, the slope of the surface causing light incident perpendicular to the first major surface of the second microstructured film to be blocked by the first major surface or the surface of at least one other microstructure after reflection.

[0132] The multilayer optical film is composed of one or more alternating first and second inorganic optical layers that cooperate to reflect and absorb light incident perpendicularly to the first major surface of the second microstructured film, and reflect and absorb an average of 50, 60, 70, 80, 90, or 95% or more of incident ultraviolet light over a wavelength reflection band of at least 30 nanometers in the wavelength range of 190 nanometers (nm) to 400 nm.

[0133] In a fourth aspect, another article is provided, the article comprising:

[0134] a microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom, at least a portion of the plurality of microstructures each having a surface with a slope that causes light incident perpendicular to the first major surface of the microstructured film to be blocked, after reflection, by the first major surface or the surface of at least one other microstructure;

[0135] A multilayer optical film disposed on a plurality of microstructures, the multilayer optical film being composed of one or more alternating first and second inorganic optical layers that cooperate to reflect and absorb light incident perpendicularly to a first major surface of the microstructured film, and to reflect and absorb an average of 50, 60, 70, 80, 90, or 95% or more of incident ultraviolet light over a wavelength reflection band of at least 30 nanometers in the wavelength range of 190 nanometers (nm) to 400 nm; and a (co)polymer layer disposed on the major surface of the multilayer optical film opposite the microstructured film.

[0136] The following disclosure relates to both the third and fourth aspects.

[0137] 2 , article 30 includes a first microstructured film 18 having a first major surface 21 and an opposite second major surface 23, and a release layer 16 disposed on first major surface 21 of first microstructured film 18. Article 30 further includes a (co)polymer layer 15 disposed on a major surface 27 of release layer 16 opposite first microstructured film 18, and a multilayer optical film 5 disposed on a major surface 29 of (co)polymer layer 15 opposite release layer 16. Article 30 further includes a second microstructured film 11 adjacent to a major surface 7 of multilayer optical film 5 opposite (co)polymer layer 15. Optionally, (co)polymer layer 15 is a first (co)polymer layer, and article 30 further includes a second (co)polymer layer 17 disposed between first microstructured film 18 and release layer 16.

[0138] 1D , article 30 includes a first microstructured film 18 having a first major surface 21 including a plurality of microstructures 45 protruding therefrom, and a release layer 16 disposed on the plurality of microstructures 45. Article 30 further includes a (co)polymer layer 15 disposed on release layer 16 opposite first microstructured film 18, and a multilayer optical film 5 disposed on a major surface 29 of (co)polymer layer 15 opposite release layer 16. Article 30 further includes a second microstructured film 11 adjacent to a major surface 8 of multilayer optical film 5 opposite (co)polymer layer 15. Second microstructured film 11 has first major surface 7 and opposite second major surface 9, first major surface 7 including a plurality of microstructures 47 protruding therefrom, at least a portion of which each have a surface with a slope that causes light incident normally on first major surface 7 of second microstructured film 11 to be blocked, after reflection, by first major surface 7 or the surface of at least one other microstructure. In some cases, second microstructured film 11 is directly adjacent to multilayer optical film 5, and in other cases, there may be an intermediate layer (not shown) between the two.

[0139] 1D, the microstructures 47 of the second microstructured film 11 have the inverse shape of the microstructures 45 of the first microstructured film 18. Since in the end use an article will include the second microstructured film 11, the shape of the microstructures 45 of the first microstructured film 18 should be selected to be the inverse shape of the desired shape of the microstructures 47 of the second microstructured film 11.

[0140] In use, the article is oriented in the opposite direction from that shown in FIG. 1D so that incident light reaches the microstructures 47 on the first major surface 7 of the second microstructured film 11 before reaching the opposite second major surface 9 of the second microstructured film 11. Articles of the fourth aspect, at least according to certain embodiments disclosed herein (i.e., articles having only one microstructured film), transmit light that is normally incident on the first major surface of the second microstructured film, and transmit an average of 50, 60, 70, 80, 90, or 95% or more of normally incident visible light in the wavelength range from greater than 400 nm to 700 nm. Articles according to certain preferred embodiments of the present disclosure have a transmittance of 425 megajoules per square meter (MJ / m 2 ) after irradiation with ultraviolet light, 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%.

[0141] In certain embodiments, the outermost inorganic layer in use is the second inorganic optical layer (e.g., 13N in FIG. 2) and has a thickness of at least 70 nm, thereby reducing the amount of light reflected from the outer surface of the article and increasing the transmission of light between 400 nm and 700 nm, which is particularly useful when the article is used in photovoltaic applications, i.e., to allow visible light to reach solar cells.

[0142] In certain embodiments, at least one of the first optical layers closest to the exterior of the article in use (e.g., 12N in FIG. 2) or closest to the microstructured film (e.g., 12A in FIG. 2) has a thickness that is 95% or less, 90% or less, 85% or less, or 80% or less of the thickness of the other first optical layer, which reduces the amount of light in the 400 nm to 700 nm wavelength range that is reflected from the outer surface of the article, and is particularly useful for allowing visible light to reach the solar cell.

[0143] The alternating first and second inorganic optical layers cooperate to reflect and absorb light incident perpendicularly to the first major surface of the second microstructured film 11, reflecting and absorbing an average of 50, 60, 70, 80, 90, or 95% (preferably at least 80, 90, or 95%) or more of the incident ultraviolet light over a wavelength reflection band of at least 30 nanometers in the wavelength range of 190 nanometers (nm) to 400 nm.

[0144] In some cases, the alternating first and second inorganic optical layers cooperate to reflect and absorb light incident normally on the first major surface of the microstructured film 11, reflecting and absorbing an average of 60, 70, 80, 90, or 95% or more of the incident ultraviolet light over a wavelength reflection band of at least 30 nanometers in 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.

[0145] In some cases, the alternating first and second inorganic optical layers cooperate to reflect and absorb light incident perpendicularly to the first major surface of the microstructured film 11, reflecting and absorbing an average of 60, 70, 80, 90, or 95% or more of the incident ultraviolet light over a wavelength reflection band greater than at least 30 nanometers in the wavelength range of 190 nm to 400 nm, for example, a wavelength reflection band of at least 50 nanometers, 75 nanometers, 100 nanometers, 125 nanometers, 150 nanometers, or 175 nanometers.

[0146] The alternating first and second inorganic optical layers cooperate to reflect and absorb, so that some of the incident ultraviolet light is absorbed and some is reflected. In some cases, the alternating first and second inorganic optical layers cooperate to absorb light that is incident normal to the first major surface of microstructured film 11, absorbing an average of 30, 40, 50, 60, 70, 80, 90, or 95% or more of the incident light over a wavelength band of at least 30 nanometers in the wavelength range of 190 nm to less than 350 nm. In some cases, the alternating first and second inorganic optical layers cooperate to reflect light incident normally on the first major surface of the microstructured film 11, reflecting an average of 30, 40, 50, 60, 70, 80, 90, or 95% or more of the incident light over a wavelength band of at least 30 nanometers in the wavelength ranges of 190 nm to less than 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.

[0147] In certain embodiments, the alternating first and second inorganic optical layers cooperate to transmit light incident perpendicularly to the first major surface of the microstructured film 11, transmitting an average of 50, 60, 70, 80, 90, or 95% or more of the incident visible light in the wavelength range from greater than 400 nm to 700 nm.

[0148] In some embodiments, an article (e.g., the entire article) of the fourth aspect (i.e., an article having only one microstructured film) transmits an average of 50, 60, 70, 80, 90, or 95% or more of normally incident visible light in the wavelength range from greater than 400 nm to 700 nm. Such amounts of transmission of incident visible light are particularly useful when the article is used in a solar cell array application, for allowing visible light to reach the solar cells of the array.

[0149] 1D and 2, article 30 further includes an optional additional layer 14 that is a tie layer or a substrate, or both. Additional layer 14 is disposed on a major surface 9 of second microstructured film 11 opposite multilayer optical film 5. A wide variety of materials are suitable for such tie and / or substrate layers, and additional layer 14 includes a carrier substrate (e.g., a free-standing substrate), a single adhesive layer, adhesive tape, double-sided adhesive tape, a primer-bonding layer, a film, etc. Thus, the additional layer may be a single layer, as shown in FIG. 1D, or multiple layers.

[0150] 2 , article 40 includes a microstructured film 11 having a first major surface 7 and an opposite second major surface 9. First major surface 7 has a plurality of microstructures (not shown) protruding therefrom. Article 40 further includes a multilayer optical film 5 disposed on first major surface 7 of microstructured film 11, and a (co)polymer layer 15 disposed on a major surface 22 of multilayer optical film 5 opposite microstructured film 11.

[0151] The (e.g., first) microstructured film 18, release layer 16, (co)polymer layer 15, multilayer optical film 5, and optional second (co)polymer layer 17 are as described in detail above with respect to the first and second embodiment transfer articles, respectively. Optionally, the article further includes an additional layer 14 that is a tie layer or a substrate, or both, as described above with respect to FIG. 1D.

[0152] In some embodiments, the (e.g., second) microstructured film 11 comprises a cured polysiloxane, a silicone-based thermoplastic polymer, PET, a cured urethane, a thermoplastic urethane, a cured (meth)acrylate, a cured epoxy, a cured vinyl ether, a cured oxetane, a cured thiol-acrylate, a cured thiol-ene, PMMA, coPMMA, a polyimide, a cyclic olefin copolymer, a cyclic olefin polymer, a polycarbonate, PEN, or a fluoropolymer (co)polymer comprising polymerized units derived from one or more monomers selected from tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, perfluoroalkoxyalkylene, or vinyl fluoride, or a combination thereof. Optionally, any of the cured polymeric materials listed above may be crosslinked. In certain embodiments of the present disclosure, the (co)polymer layer and / or the microstructured film may further comprise an additive such as an ultraviolet absorber, a hindered amine light stabilizer, an antioxidant, or a combination thereof, such as any of the additives described above.

[0153] In some cases, the second microstructured film comprises a cured polysiloxane, a silicone-based thermoplastic polymer, or a combination thereof. An advantage of producing an article from a transfer article is that soft materials such as silicone-based polymers can be used without the need to support the deposition of a multilayer optical film on the microstructured film during article formation.

[0154] If a polyimide or high temperature fluoropolymer is used, it will be a generally flat backing layer in combination with other polymeric materials (e.g., cured (meth)acrylates) that form the microstructure of the microstructured film.

[0155] In certain embodiments, the second microstructured film comprises a cured urethane, a cured (meth)acrylate, coPMMA, PMMA, or a combination thereof, and the second microstructured film optionally also comprises an ultraviolet absorber, a hindered amine light stabilizer, an antioxidant, or a combination thereof. The inclusion of such additives can protect the microstructured film material from UV radiation damage.

[0156] The article can be subjected to various post-treatments, such as heat treatment, UV or vacuum UV (VUV) treatment, electron beam treatment, or plasma treatment. Heat treatment can be performed by passing the article through an oven or by directly heating the article in the coating apparatus (e.g., using an infrared heater or directly heating on a drum). Heat treatment can be performed, for example, at temperatures of about 30°C to about 200°C, about 35°C to about 150°C, or about 40°C to about 70°C.

[0157] Any of the first microstructured film, first (co)polymer layer, second (co)polymer layer, release layer, and multilayer optical film present in the article of the third or fourth embodiment may be similar to those films and / or layers described in detail above with respect to the transfer article of the first or second embodiment.

[0158] [method] In a fifth aspect, there is provided a method of manufacturing an article, the method comprising:

[0159] providing a transfer article according to the first or second aspect;

[0160] applying a polymeric or crosslinkable material onto an outer major surface of the transfer article opposite the first microstructured film;

[0161] curing the polymeric or crosslinkable material to form a second microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom, at least some of the plurality of microstructures each having a surface with a slope that causes light incident perpendicularly to the first major surface of the second microstructured film to be blocked after reflection by the first major surface or the surface of at least one other microstructure, and the first major surface of the second microstructured film is adjacent to the multilayer optical film;

[0162] Removing the release layer from the transfer article.

[0163] In some cases, the transfer article is according to the first embodiment, and the outer major surface of the transfer article comprises the major surface of the multilayer optical film opposite the first (co)polymer layer. In other words, in some cases, the transfer article used in the method comprises, in order, a microstructured film, a release layer, a (co)polymer layer, and a multilayer optical film, and the multilayer optical film is the outer layer of the transfer article. Here, outer layer means that the layer is the outermost layer of the transfer article.

[0164] In some cases, the transfer article is according to the first embodiment, and the method further comprises removing the first (co)polymer layer after removing the release layer. In other words, in some cases, the transfer article used in the method comprises, in order, a microstructured film, a release layer, a (co)polymer layer, and a multilayer optical film, and the (co)polymer layer adjacent to the multilayer optical film is removed after removing the release layer. In many cases, the (co)polymer layer is removed by etching.

[0165] Applicable etching processes are not particularly limited and may include reactive ion etching and etching using any type of plasma. In one embodiment, the (co)polymer layer is removed by reactive ion etching. Reactive ion etching (RIE) is a directional etching process that uses ion bombardment to remove material. RIE systems are used to remove organic or inorganic materials by etching surfaces perpendicular to the direction of ion bombardment. The most notable difference between reactive ion etching and isotropic plasma etching is the etching direction. Reactive ion etching is characterized by a ratio of vertical to lateral etch rates greater than 1. A reactive ion etching system is centered around a durable vacuum chamber. Before starting the etching process, the chamber is evacuated to a base pressure of less than 1 Torr, less than 100 mTorr, less than 20 mTorr, less than 10 mTorr, or less than 1 mTorr. An electrode holds the material to be processed and is electrically insulated from the vacuum chamber. The electrode may be cylindrical and rotatable. A counter electrode is also provided within the chamber and may consist of the wall of the vacuum reactor. Gas containing an etchant is introduced into the chamber via a control valve. The process pressure is maintained by continuously evacuating the gas in the chamber using a vacuum pump. The type of gas used varies depending on the etching process. Carbon tetrafluoride (CF), sulfur hexafluoride (SF), octafluoropropane (C3F8), fluoroform (CHF3), boron trichloride (BCl3), hydrogen bromide (HBr), chlorine, argon, and oxygen are commonly used for etching. RF power is applied to the electrode to generate a plasma. The sample is transported through the plasma on the electrode and held for a predetermined time to achieve the desired etch depth. Reactive ion etching is well known to those skilled in the art and is further described in U.S. Patent No. 8,460,568 (David et al.), which is incorporated herein. Gases used to generate the etching plasma typically include oxygen gas and a fluorocarbon (e.g., CF4, C2F6, or C3F8).The molar concentration of the fluorocarbon gas in the gas mixture typically ranges from 0 to 60%, depending on the particular type of fluorocarbon and the composition of the (co)polymer layer being removed. Argon is also a useful gas for plasma etching in combination with oxygen and / or a fluorocarbon. In some cases, oxygen alone is used to generate the etching plasma. Typically, plasma etching uses a power of about 0.05 to about 1 watt per square centimeter (W / cm). 2 ) range of power densities can be applied.

[0166] In some cases, the transfer article is according to the second embodiment, and the outer major surface of the transfer article comprises a major surface of the first (co)polymer layer.

[0167] In certain embodiments, the method further comprises applying a tie layer, a substrate, or both, to the second major surface of the second microstructured film. Suitable tie layers and substrates are as described above.

[0168] [Example enumeration of embodiments]

[0169] In a first embodiment, a transfer article is provided. The transfer article includes a microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom. At least a portion of the plurality of microstructures each have a surface, the slope of which causes light incident perpendicularly to the first major surface of the microstructured film to be blocked by the first major surface or the surface of at least one other microstructure after reflection. The transfer article further includes a release layer disposed on the plurality of microstructures, the release layer including a metal layer or a doped semiconductor layer. The transfer article further includes a (co)polymer layer disposed on the major surface of the release layer opposite the microstructured film, and a multilayer optical film disposed on the major surface of the (co)polymer layer opposite the release layer. The multilayer optical film is composed of one or more alternating first and second inorganic optical layers that cooperate to reflect and absorb light incident normally to the first major surface of the microstructured film, and reflect and absorb an average of 50, 60, 70, 80, 90, or 95% or more of incident ultraviolet light over a wavelength reflection band of at least 30 nanometers in the wavelength range of 190 nanometers (nm) to 400 nm.

[0170] In a second embodiment, a transfer article according to the first embodiment is provided, wherein the microstructured film comprises polyethylene terephthalate (PET), cured polysiloxane, silicone-based thermoplastic polymer, cured urethane, thermoplastic urethane, cured (meth)acrylate, cured epoxy, cured vinyl ether, cured oxetane, cured thiol-acrylate, cured thiol-ene, polypropylene, polyethylene, PMMA, coPMMA, polyimide, cyclic olefin copolymer, cyclic olefin polymer, polycarbonate, polyethylene naphthalate (PEN), or a fluoropolymer (co)polymer comprising polymerized units derived from one or more monomers selected from tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, perfluoroalkoxyalkylene, or vinyl fluoride, or a combination thereof.

[0171] In a third embodiment, a transfer article according to the first or second embodiment is provided, wherein the (co)polymer layer is a first (co)polymer layer, and the transfer article further comprises a second (co)polymer layer disposed between the microstructured film and the release layer.

[0172] In a fourth embodiment, a transfer article according to the third embodiment is provided, wherein at least one of the first (co)polymer layer or the second (co)polymer layer comprises 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.

[0173] In a fifth embodiment, a transfer article according to any one of the first to fourth embodiments is provided, wherein the release layer comprises a metal layer comprising at least one selected from the group consisting of a single metal, a mixture of two or more metals, an intermetallic compound or alloy, a semi-metal or metalloid, a metal oxide, a metal and mixed metal oxide, a metal and mixed metal fluoride, a metal and mixed metal nitride, a metal and mixed metal carbide, a metal and mixed metal carbonitride, a metal and mixed metal oxynitride, a metal and mixed metal boride, a metal and mixed metal oxyboride, a metal and mixed metal silicide, a diamond-like carbon, a diamond-like glass, graphene, and combinations thereof.

[0174] In a sixth embodiment, a transfer article according to any one of the first to fifth embodiments is provided, wherein the release layer comprises copper oxide or aluminum silicon oxide.

[0175] In a seventh embodiment, a transfer article according to any one of the first to sixth embodiments is provided, wherein the plurality of microstructures have an aspect ratio of height to width of 10:1 or less, 8:1 or less, 6:1 or less, 4:1 or less, 2:1 or less, or 1:1 or less.

[0176] In an eighth embodiment, a transfer article according to any one of the first to seventh embodiments is provided, wherein at least a portion of the microstructure has at least one sloping sidewall with a peak angle of 90 degrees or less and 5 degrees, 15 degrees, 25 degrees, 35 degrees, or 45 degrees or more.

[0177] In a ninth embodiment, a transfer article according to any one of the first to eighth embodiments is provided, wherein the surfaces having a slope that causes light incident perpendicularly to the first major surface of the microstructured film to be blocked by the first major surface or at least one other microstructured surface after reflection each have the same slope.

[0178] In a tenth embodiment, a transfer article according to any one of the first to ninth embodiments is provided, wherein at least a portion of the microstructures have a shape with a triangular cross section.

[0179] In an eleventh embodiment, a transfer article according to any one of the first to tenth embodiments is provided, wherein the microstructure has a shape that is a prism, a pyramid, an inverted pyramid, a diffraction grating, an inverted cone, or a cone.

[0180] In a twelfth embodiment, there is provided a transfer article according to any one of the first to eleventh embodiments, wherein the microstructures have a height of 0.5 micrometers to 500 micrometers.

[0181] In a thirteenth embodiment, a transfer article according to any one of the first to twelfth embodiments is provided, wherein each of the first and second inorganic optical layers independently has a thickness of 20 nm to 400 nm.

[0182] In a fourteenth embodiment, there is provided a transfer article according to any one of the first to thirteenth embodiments, wherein the first optical layers comprise 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 layers comprise at least one of silicon oxide, silicon aluminum oxide, N-type or P-type doped silicon oxide, aluminum oxide, aluminum fluoride, magnesium fluoride, calcium fluoride, indium tin oxide, or zinc oxide.

[0183] In a fifteenth embodiment, a transfer article according to any one of the first to fourteenth embodiments is provided, wherein the first optical layers comprise at least one of niobium oxide or titanium oxide, and the second optical layers comprise silicon aluminum oxide.

[0184] In a sixteenth embodiment, a transfer article according to any one of the first to fifteenth embodiments is provided, wherein the multilayer optical film is formed from at least one first optical layer and two second optical layers.

[0185] In a seventeenth embodiment, a transfer article according to any one of the first to sixteenth embodiments is provided, wherein the first (co)polymer layer is substantially transparent.

[0186] In an eighteenth embodiment, an article is provided. The article includes a first microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom. At least a portion of the plurality of microstructures each have a surface with a slope such that light incident perpendicularly to the first major surface of the first microstructured film is blocked by the first major surface or the surface of at least one other microstructure after reflection. The article further includes a release layer including a metal layer or a doped semiconductor layer disposed on the plurality of microstructures, a (co)polymer layer disposed on the major surface of the release layer opposite the first microstructured film, a multilayer optical film disposed on the major surface of the (co)polymer layer opposite the release layer, and a second microstructured film adjacent to the major surface of the multilayer optical film opposite the (co)polymer layer. The second microstructured film has a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom, at least a portion of the plurality of microstructures each having a surface with a slope that causes light incident perpendicularly to the first major surface of the second microstructured film to be blocked after reflection by the first major surface or by a surface of at least one other microstructure. The multilayer optical film is comprised of one or more alternating first and second inorganic optical layers that cooperate to reflect and absorb an average of 50, 60, 70, 80, 90, or 95% or more of incident ultraviolet light perpendicularly incident on the first major surface of the second microstructured film over a wavelength reflection band of at least 30 nanometers in the wavelength range of 190 nanometers to 400 nm.

[0187] In a nineteenth embodiment, an article according to the eighteenth embodiment is provided, wherein the second microstructured film comprises a cured polysiloxane, a silicone-based thermoplastic polymer, polyethylene terephthalate (PET), a cured urethane, a thermoplastic urethane, a cured (meth)acrylate, PMMA, coPMMA, a polyimide, a cyclic olefin copolymer, a cyclic olefin polymer, a polycarbonate, polyethylene naphthalate (PEN), or a fluoropolymer (co)polymer comprising polymerized units derived from one or more monomers selected from tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, perfluoroalkoxyalkylene, or vinyl fluoride.

[0188] In a twentieth embodiment, an article of the eighteenth or nineteenth embodiment is provided, wherein the second microstructured film comprises a cured urethane, a cured (meth)acrylate, coPMMA, PMMA, or a combination thereof, and further wherein the second microstructured film optionally comprises an ultraviolet absorber, a hindered amine light stabilizer, an antioxidant, or a combination thereof.

[0189] In a twenty-first embodiment, an article according to the eighteenth or nineteenth embodiment is provided, wherein the second microstructured film comprises a cured polysiloxane, a silicone-based thermoplastic polymer, or a combination thereof.

[0190] In a 22nd embodiment, an article according to any of the 18th to 21st embodiments is provided, wherein the (co)polymer layer is a first (co)polymer layer, and the article further comprises a second (co)polymer layer disposed between the first microstructured film and the release layer.

[0191] In a 23rd embodiment, an article described in any one of claims 18 to 22 is provided, further comprising a bonding layer, a substrate, or both, disposed on the major surface of the second microstructured film opposite the multilayer optical film.

[0192] In a twenty-fourth embodiment, the article of any one of claims 18 to 23 is provided, wherein the second microstructured film is directly adjacent to the multilayer optical film.

[0193] In a twenty-fifth embodiment, another article is provided. The article includes a microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom. At least some of the microstructures each have a sloped surface that causes light incident perpendicularly to the first major surface of the microstructured film to be blocked by the first major surface or a surface of at least one other microstructure after reflection. The article further includes a multilayer optical film disposed on the plurality of microstructures, and a (co)polymer layer disposed on the major surface of the multilayer optical film opposite the microstructured film. The multilayer optical film is composed of one or more alternating first and second inorganic optical layers that cooperate to reflect and absorb light incident normally on the first major surface of the microstructured film, and reflect and absorb an average of 50, 60, 70, 80, 90, or 95% or more of incident ultraviolet light over a wavelength reflection band of at least 30 nanometers in the wavelength range of 190 nanometers (nm) to 400 nm.

[0194] In a twenty-sixth embodiment, the article of the twenty-fifth embodiment is provided, further comprising a tie layer, a substrate, or both, disposed on the second major surface of the microstructured film.

[0195] In a 27th embodiment, there is provided an article according to the 25th or 26th embodiment, which transmits light normally incident on the first major surface of the second microstructured film, and transmits an average of 50, 60, 70, 80, 90, or 95% or more of normally incident visible light in the wavelength range from greater than 400 nm to 700 nm.

[0196] In a 28th embodiment, the article of any one of claims 25 to 27 is provided, wherein the reduction in average transmittance of the article in the wavelength range of 400 nm to 700 nm is 425 megajoules per square meter (MJ / m 2) is less than 20%, less than 10%, less than 5%, or less than 1% after ultraviolet light exposure.

[0197] In a twenty-ninth embodiment, another transfer article is provided. The transfer article includes a microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom. At least some of the microstructures each have a sloped surface that causes light incident perpendicularly to the first major surface of the microstructured film to be blocked by the first major surface or by a surface of at least one other microstructure after reflection. The transfer article further includes a release layer disposed on the plurality of microstructures, the release layer including a metal layer or a doped semiconductor layer, and a (co)polymer layer disposed on the major surface of the release layer opposite the microstructured film, the (co)polymer layer further including an ultraviolet absorber, a hindered amine light stabilizer, an antioxidant, or a combination thereof.

[0198] In a 30th embodiment, there is provided a transfer article according to the 29th embodiment, wherein the (co)polymer layer is a first (co)polymer layer and further comprises a second (co)polymer layer disposed between the microstructured film and the release layer.

[0199] In a thirty-first embodiment, a method for making an article is provided. The method includes providing a transfer article according to any one of the first to seventeenth, twenty-ninth, or thirty embodiments, applying a polymeric or crosslinkable material to an outer major surface of the transfer article opposite the first microstructured film, curing the polymeric or crosslinkable material to form a second microstructured film having a first major surface and an opposite second major surface, and removing the release layer from the transfer article. The first major surface of the second microstructured film includes a plurality of microstructures protruding therefrom, at least some of the microstructures each having a sloped surface that causes light incident perpendicularly to the first major surface of the second microstructured film to be blocked by the first major surface or a surface of at least one other microstructure after reflection, and the first major surface of the second microstructured film is adjacent to the multilayer optical film.

[0200] In a 32nd embodiment, the method described in the 31st embodiment is provided, wherein the transfer article is described in any one of the 1st to 17th embodiments, and the outer major surface of the transfer article comprises the major surface of the multilayer optical film opposite the first (co)polymer layer.

[0201] In a 33rd embodiment, there is provided a method according to the 31st or 32nd embodiment, wherein the transfer article is according to any one of the 1st to 17th embodiments, and further comprising the step of removing the first (co)polymer layer after removing the release layer.

[0202] In a thirty-fourth embodiment, there is provided a method according to the thirty-third embodiment, wherein the first (co)polymer layer is removed using etching.

[0203] In a thirty-fifth embodiment, a method according to the thirty-first embodiment is provided, wherein the transfer article is according to the twenty-ninth or thirtieth embodiment, and the outer major surface of the transfer article comprises the major surface of the first (co)polymer layer.

[0204] In a thirty-sixth embodiment, there is provided a method according to any one of the thirty-first to thirty-fifth embodiments, further comprising depositing a tie layer, a substrate, or both, on a second major surface of the second microstructured film. [Example]

[0205] Unless otherwise stated or apparent from context, all parts, percentages, ratios, etc. in the examples and elsewhere in this specification are by weight. [Table 1]

[0206] <Test Method> Spectral Property Modeling Test: Prior to fabrication, the optical properties (transmittance, reflectance, and absorptance) of the desired inorganic coating were modeled to accurately determine the required thickness of the optical coating layer. To perform this modeling, test samples 1 and 2 were measured using an ellipsometer (RC2 Ellipsometer, JA Woolam, Lincoln, NE) to determine the spectral refractive index (n) and extinction coefficient (k) of the deposited TiO2 and SiO2 samples. The resulting n and k values ​​were then entered into optical modeling software (Essential MaCleod, The Thin Film Center, Tucson, AZ) to calculate the reflectance, transmission, and absorption spectra of the multilayer optical films prepared as described below. All structures were modeled using a PET substrate, a 45° incident angle, and with the top oxide layer of the coating facing the air. Note that the SR833 and silicone layers were not included in the modeling. The modeled results for reflection, absorption, and transmission are reported as average percentages over the wavelength range in the Reflection and Absorption Results Table and the Transmission Results Table. Note that the modeling only calculates the transmittance, reflectance, and absorptance of the inorganic optical coating, and does not include the absorption or backside reflection of the substrate material.

[0207] Tests for Measuring Spectral Properties: The spectral transmittance and reflectance of freestanding examples of articles were measured using a spectrophotometer (trade name "LAMBDA 1050" manufactured by PerkinElmer, Inc., Waltham, Massachusetts). Absorbance was calculated (as a percentage) as 100 - reflectance - transmittance. The measured spectral reflectance, absorbance, and transmittance are reported in the Reflection and Absorption Results Table and the Transmission Results Table as average percentages over the wavelength range.

[0208] Sunlight Degradation Test: Samples were exposed in an Atlas Ci5000 WeatherOmeter (AMETEK, Berwyn, PA) equipped with a xenon arc lamp as the light source and quartz inner and outer filters. The xenon lamp approximates the spectral shape of sunlight output (ASTM E490), and the quartz filter set provides minimal attenuation to the xenon lamp's spectral output distribution. Samples were placed on custom stainless steel and aluminum holders. The exposure surface was positioned 19 inches (48.3 cm) from the center of the lamp. Irradiance was 340 nm, 1.3 watts per square meter (W / m) at the rack. 2 The ambient temperature in the WeatherOmeter was controlled at 47°C, the black panel thermometer (BPT) was controlled at 70°C on the rack surface, and the relative humidity was controlled at 30%. An aluminum panel was placed behind the sample. The sample was exposed to a cumulative irradiation dose of at least 425 megajoules per square meter (MJ / m) in the wavelength range of 250 to 385 nm. 2 ) were exposed to

[0209] The change in transmittance was calculated using the following formula:

number

[0210] [Transfer Test]: To determine whether a multilayer optical film can be transferred from a state in which it is bonded (directly or indirectly) to one microstructured substrate to another microstructured substrate, that is, in an article having a first microstructured film and a second microstructured film, with a multilayer optical film disposed between the first and second microstructured films (optionally with one or more additional layers positioned between the first and second microstructured films), a transfer test was performed to determine whether the first and second microstructured films can be separated so that the multilayer optical film can be transferred from a state in which it is bonded to the first microstructured film to a state in which it is bonded to the second microstructured film. For this test, the articles of Example 3, Example 6, or Comparative Example 1 were used.

[0211] Attempts to separate the first and second microstructured films were performed in the following manner: First, a fresh razor blade was used to cut a rectangular incision into the second microstructured film side of the article, such that the cut area was smaller than the original piece of article but large enough for subsequent characterization (e.g., a 2 inch x 2 inch (5.08 centimeters x 5.08 centimeters) initial piece of article was used, and then a 1.5 inch x 1.5 inch (3.81 centimeters x 3.81 centimeters) area was cut out, large enough for spectroscopic measurements). When cutting out this area, care was taken to cut all the way through the second microstructured film and all the way to the first microstructured film, but not all the way through the first microstructured film. The article was then placed on a work bench with the first microstructured surface facing down and the second microstructured film facing up. 3M polyester tape was then applied to both the surface of the second microstructured film and the work bench, securing the corners of the second microstructured film to the work bench. The corners were secured to the work bench to prevent the substrate from lifting during the separation operation. Next, 3M polyester tape was applied to one end of the rectangular cut area of ​​the second microstructured film, extending 1 centimeter into the cut area. The tape was then used as a mechanical gripper to attempt to peel the second microstructured film from the first microstructured film. The results of the separation operation were recorded qualitatively, such as "the first and second microstructured films could not be separated" or "the films were successfully separated." If separation was possible, the optical properties of the separated second microstructured film were measured to assess whether transfer of the multilayer optical film had occurred (i.e., by measuring the optical properties of the film to confirm the optical characteristics of the multilayer optical film), and the assessment results were reported qualitatively, for example, as "the optical characteristics of the deposited multilayer film are present / absent in the second microstructured film." The results of the transfer test are shown in the Transfer Test Results Table below.

[0212] <Test sample> Test Sample 1: A 70 nm thick TiO2 layer was deposited on a silicon chip using the following method. The vapor coater used was a Denton Vacuum optical coater consisting of a five-axis planetary drive system mounted approximately 30 inches (76.2 cm) above a four-pocket Temescal electron beam gun (Ferro Tec Corporation, Livermore, CA). The planetary drive system held the substrate perpendicular to the evaporation source and provided planetary motion for the substrate disk to move in and out of the evaporation plume during deposition. The specific deposition process was as follows: a) The deposition apparatus was vented to atmosphere and one of the five planets was removed. The substrate for coating was prepared by gluing / taping it to the planet with polyimide tape. b) The planet was re-installed and, if necessary, the other four planets were similarly configured and re-installed in the device. c) Close the chamber and apply a vacuum <2×10 -5 Torr (2.7 × 10 -3 The pressure was reduced to 100 Pa. d) Once the vacuum in the deposition apparatus had been sufficiently reduced, ion beam treatment was carried out using a Kaufman type ion source at a voltage of 400 V for approximately 10 minutes as a pretreatment to ensure adhesion of the deposited coating to the substrate before applying the oxide film. e) Oxygen gas was introduced via an MKS mass flow controller (obtained from MKS Instruments, Inc., Andover, MA) at a flow rate of 4.0 x 10 -5 Torr (5.3 × 10 -3 A pressure of 100 Pa was obtained, which was typically about 10 standard cubic centimeters per minute (sccm) of oxygen gas introduced. f) To prepare the coating and obtain a high level of uniformity on the mounted substrate, the planetary drive was started and moved through the deposition apparatus at a rotational speed of about 60 rpm. g) The Temescal electron beam gun power supply was activated. A voltage of 10 kV and a current of several mA were applied to the filament of the electron beam gun to heat the deposition source material within the gun. The deposition source was heated and controlled via an Eddy Optical Monitoring System (OMS) (Eddy Company, Apple Valley, CA). The deposition source was heated until the desired deposition rate was reached, which was 2 Å / s for TiO2 and 4 Å / s for SiO2. When the desired deposition rate of the material was reached and stabilized, the shutter separating the deposition source from the planetary was opened, and deposition was continued while the OMS maintained that rate. When the desired optical thickness was reached, the shutter was closed, and the OMS stopped supplying power to the electron beam source. h) The main power was turned off and the source was allowed to cool for approximately 10 minutes. i) This process was repeated for each additional layer / material type until the entire desired multilayer optical film was deposited. j) The chamber was vented to atmospheric pressure with N2 gas, each planet was removed, and the substrate was recovered from each planet.

[0213] Test Sample 2: A 115 nm thick SiO 2 layer was deposited on a silicon chip in the same manner as Test Sample 1.

[0214] <Example> Example 1: The transferable structured acrylates were fabricated using a roll-to-roll vacuum coating apparatus similar to that described in U.S. Patent Application Publication No. 2010 / 0316852 (Condo et al.), with the addition of a second evaporator and curing system between the plasma pretreatment station and the first sputtering system, and the evaporator described in U.S. Patent No. 8,658,248 (Anderson et al.). A 0.05 mm thick, 14 inch (35.6 cm) wide BEF4 substrate was attached to the coating apparatus in an infinite roll format, positioned so that the microstructured side of the BEF4 was exposed to the treatment / coating process. The BEF4 was prepared by the addition of copper oxide (CuO) to the BEF4 surface. xTo improve the adhesion of the CuO layer, the film was prepared for coating by nitrogen plasma treatment. The film was treated with nitrogen plasma using a titanium cathode operating at 20 W power, while the backside of the film was in contact with a coating drum cooled to 0°C, while traveling at a web speed of 34 fpm (10.3 meters per minute). In a second pass, CuO was deposited on the nitrogen plasma-treated BEF4 substrate surface. x A release layer of CuO was formed. x The deposition of CuO was performed by a conventional direct current (DC) sputtering process using a Cu target operating at 1 kW power, with 120 sccm O2 and 450 sccm Ar supplied to the sputtering zone at a line speed of 3 fpm (0.9 m / min) to deposit a 20 nm thick layer on the substrate. x The coated BEF4 substrate was then unwound.

[0215] In the third pass, at a line speed of 17 fpm, CuO x An SR833 acrylate layer was formed on the layer with an estimated thickness of 500 nm. The acrylate layer was applied by ultrasonic atomization and flash evaporation, with a coating width of 12.5 inches (31.8 cm). The SR833 feed rate to the atomizer was 1.33 mL / min, the N2 carrier gas flow rate was 60 sccm, and the evaporator temperature was 260 °C. This monomer coating was applied to CuO x After condensation onto the layer, it was immediately cured with an electron beam curing gun operating at 7.0 kV, 4.0 mA.

[0216] After BEF4 was removed from the vacuum, 3M vinyl tape was manually laminated onto it using a 3M-71601 hard plastic squeegee, ensuring that the vinyl adhesive contacted the structured surface of the entire SR833 acrylate layer. The adhesive was manually peeled away, revealing the CuO layer, which remained firmly bonded to BEF4. x It was confirmed that the layer could be completely removed.

[0217] Example 2: The vapor deposition coated multilayer optical film was prepared in a manner similar to that of Test Sample 1, except that the film of Example 1 was used as the substrate and the structure deposited on the substrate of Example 1 was as shown in the Example Structure Table below. The substrate of Example 1 was taped to a planet so that the structured / coated side of the substrate of Example 1 would be coated by the vapor deposition coating process.

[0218] One important consideration when performing vapor deposition coatings on microstructured substrates is the substrate geometry. Due to the slope of the structure, the surface area of ​​a microstructured substrate increases compared to a flat substrate. As a result of that increased surface area, when the same material is vapor deposited on both a microstructured substrate and a flat substrate, the coating on the surface of the microstructured substrate will be thinner than the coating on the flat substrate. In other words, because a given vapor deposition process deposits a given volume of material on the substrate, a substrate with a larger surface area will receive a thinner coating overall (coating thickness = volume of deposited material ÷ surface area of ​​substrate).

[0219] Therefore, to achieve the desired film thickness on the microstructured substrate, the total volume of deposited material must be increased. The volume of material should be increased in proportion to the surface area ratio of the microstructured substrate to the flat substrate. In the case of the substrate in Example 1, which has a one-dimensional prismatic structure with a peak angle of 90 degrees, i.e., a tilt angle of 45 degrees, the volume of deposited material must be increased by a factor of 1 / sin(peak angle / 2) = 1 / sin(45°) = 1.414.

[0220] Example 3: A portion of the test specimen from Example 2 was coated with a layer of curable silicone elastomer Sylgard 184 and cured. Sylgard 184 curable silicone was prepared and applied using the following procedure: All processing, mixing, and handling of Sylgard 184 was performed at room temperature. Sylgard 184 silicone elastomer base and Sylgard 184 silicone elastomer curing agent were poured into a glass bottle at a volume ratio of 10:1 (base:curing agent). The materials were mixed for 1 minute using a wooden tongue depressor, taking care to avoid entrapped air. The mixture was allowed to stand for 1 hour to allow any entrapped air to degas. The mixture was then slowly poured onto the center of the test specimen from Example 2, ensuring the entire surface was covered with Sylgard 184. The Sylgard 184 was then allowed to cure at room temperature for 48 hours.

[0221] Example 4: Cured prismatic Sylgard 184 silicone elastomer with a transferred vapor-deposited coating was prepared by taking the specimen from Example 3 after the Sylgard 184 had fully cured and peeling the film substrate from the Sylgard 184 layer. The silicone was peeled from the substrate by cutting out the desired area of ​​the film to be peeled with a razor blade, taking care to cut only through the silicone layer and not through the substrate. To prevent the substrate from lifting during the peeling process, the corners of the substrate were secured to the workbench with 3M polyester tape. Next, 3M polyester tape was attached to one edge of the silicone in the area to be peeled, ensuring that the 3M polyester tape did not cover the entire area. The tape was then used as a mechanical grip to peel the silicone from the substrate. The tape was pulled perpendicular to the longitudinal direction of the prismatic shape of the BEF4 substrate, i.e., from peak to peak of the prismatic shape. This procedure resulted in the SR833 layer becoming CuO. x The layers were peeled off to obtain a Sylgard 184 film having a microstructure coated with SiO2, TiO2 and SR833 layers as shown in the Example Structure Table.

[0222] Example 5: Example 5 was prepared in the same manner as Example 2, except that the layer structure was as shown in the Example Structure Table.

[0223] Example 6: Example 6 was prepared in a similar manner to Example 3, with the following exceptions: the film of Example 5 was used as the substrate instead of the film of Example 2, and DC93-500 was used instead of Sylgard 184. The DC93-500 curable silicone was prepared and applied as follows: All processing, mixing, and handling of DC93-500 was performed at room temperature. The DC93-500 silicone elastomer base and DC93-500 silicone elastomer curing agent were poured into a glass bottle at a volume ratio of 10:1 (base:curing agent). The materials were mixed for 1 minute using a wooden tongue depressor, taking care to avoid entrapped air. The mixture was allowed to stand for 1 hour to allow any entrapped air to degas. The mixture was then slowly poured into the center of the test specimen from Example 5, ensuring the entire specimen was covered with DC93-500. The DC93-500 was then allowed to cure for 48 hours at room temperature.

[0224] Example 7: Cured prismatic DC93-500 silicone elastomer with a transferred vapor-deposited coating was prepared by taking a specimen from Example 6 after the DC93-500 had fully cured and peeling the film substrate from the DC93-500 layer. The silicone was peeled from the substrate by cutting out the desired area of ​​the film to be peeled with a razor blade, taking care to cut only through the silicone layer and not through the substrate. To prevent the substrate from lifting during the peeling process, the corners of the substrate were secured to the workbench with 3M polyester tape. Next, 3M polyester tape was applied to one edge of the silicone in the area to be peeled, preventing the tape from covering the entire peel area. The tape was then used as a mechanical grip to peel the silicone from the substrate. The tape was pulled perpendicular to the longitudinal direction of the prismatic shape of the BEF4 substrate, i.e., from peak to peak of the prismatic shape. This procedure resulted in the SR833 layer becoming CuO. xThe layers were peeled off to obtain a DC93-500 film having a microstructure coated with SiO2, TiO2 and SR833 layers as shown in the Example Structure Table.

[0225] Comparative Example 1 In Comparative Example 1, a vapor deposition-coated multilayer optical film was first formed in the same manner as in Example 2, except that a BEF4 test piece was used as the substrate instead of the test piece used in Example 1. The structure of the vapor deposition-coated multilayer optical film is shown in layers 1 to 11 in the comparative example structure table. Next, a layer of DC93-500 curable silicone elastomer was coated and cured on the outer surface (layer 12) of the vapor deposition-coated multilayer optical film in the same manner as the coating and curing of the DC93-500 layer in Example 6.

[0226] Comparative Example 2 Comparative Example 2 is a test piece of BEF4 film. [Table 2] [Table 3] [Table 4] [Table 5] [Table 6] [Table 7] [Table 8]

[0227] While specific embodiments have been illustrated and described herein, those skilled in the art will recognize that various alternative and / or equivalent embodiments may be substituted for the specific embodiments shown. This application is intended to cover any modifications or variations of the specific embodiments described herein. Accordingly, it is intended that the specification be limited only by the following claims and their equivalents.

[0228] Furthermore, all references and patents cited herein are hereby incorporated by reference in their entirety as if each were individually cited. In the event of a conflict or inconsistency between the teachings of an incorporated reference and the teachings of this application, the teachings of this specification shall control. While various exemplary embodiments have been described, these and other embodiments are within the scope of the following claims.

Claims

1. a microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom, at least a portion of the plurality of microstructures each having a surface with a slope such that light incident normally to the first major surface of the microstructured film is intercepted, after refraction, at the first major surface or at least one other microstructured surface; a release layer disposed over the plurality of microstructures, the release layer comprising a metal layer or a doped semiconductor layer; a (co)polymer layer disposed on a major surface of the release layer opposite the microstructured film; and a multilayer optical film disposed on the major surface of the (co)polymer layer opposite the release layer, the multilayer optical film being comprised of one or more alternating first and second inorganic optical layers that cooperate to reflect and absorb light incident normally to the first major surface of the microstructured film, and to reflect and absorb an average of 50, 60, 70, 80, 90, or 95% or more of incident ultraviolet light over a wavelength reflection band of at least 30 nanometers in the wavelength range of 190 nanometers to 400 nm; A transfer article comprising:

2. 10. The transfer article of claim 1, wherein the microstructured film comprises polyethylene terephthalate (PET), cured polysiloxane, silicone-based thermoplastic polymer, cured urethane, thermoplastic urethane, cured (meth)acrylate, cured epoxy, cured vinyl ether, cured oxetane, cured thiol-acrylate, cured thiol-ene, polypropylene, polyethylene, PMMA, coPMMA, polyimide, cyclic olefin copolymer, cyclic olefin polymer, polycarbonate, polyethylene naphthalate (PEN), or a fluoropolymer (co)polymer comprising polymerized units derived from one or more monomers selected from tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, perfluoroalkoxyalkylene, or vinyl fluoride, or a combination thereof.

3. The transfer article of claim 1 or 2, wherein the (co)polymer layer is a first (co)polymer layer, and the transfer article further comprises a second (co)polymer layer disposed between the microstructured film and the release layer.

4. 4. The transfer article of claim 3, wherein at least one of the first (co)polymer layer or the second (co)polymer layer comprises 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.

5. 5. The transfer article of any one of claims 1 to 4, wherein the release layer comprises a metal layer comprising at least one selected from the group consisting of a single metal, a mixture of two or more metals, an intermetallic compound or alloy, a semimetal or metalloid, a metal oxide, a metal and mixed metal oxide, a metal and mixed metal fluoride, a metal and mixed metal nitride, a metal and mixed metal carbide, a metal and mixed metal carbonitride, a metal and mixed metal oxynitride, a metal and mixed metal boride, a metal and mixed metal oxyboride, a metal and mixed metal silicide, diamond-like carbon, a diamond-like glass, graphene, and combinations thereof.

6. The transfer article of any one of claims 1 to 5, wherein the release layer comprises copper oxide or silicon aluminum oxide.

7. 7. The transfer article of claim 1, wherein at least a portion of the microstructures have at least one sloping sidewall with a peak angle of 90 degrees or less and 5 degrees, 15 degrees, 25 degrees, 35 degrees, or 45 degrees or more.

8. The transfer article according to any one of claims 1 to 7, wherein the surfaces having a slope that causes light that is incident perpendicularly to the first main surface of the microstructured film to be blocked by the first main surface or at least one other microstructured surface after reflection each have the same slope.

9. The transfer article according to any one of claims 1 to 8, wherein at least a portion of the plurality of microstructures have a shape with a triangular cross section.

10. The transferred article according to any one of claims 1 to 9, wherein the microstructure has a shape that is a prism, a pyramid, an inverted pyramid, a diffraction grating, an inverted cone, or a cone.

11. The transfer article of any one of claims 1 to 10, wherein each of the first and second inorganic optical layers independently has a thickness of from 20 nm to 400 nm.

12. 12. The transfer article of claim 1, wherein 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, and the second optical layer comprises at least one of silicon oxide, silicon aluminum oxide, N-type or P-type doped silicon oxide, aluminum oxide, aluminum fluoride, magnesium fluoride, calcium fluoride, indium tin oxide, or zinc oxide.

13. a first microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom, at least a portion of the plurality of microstructures each having a surface with a slope such that light incident perpendicular to the first major surface of the first microstructured film is blocked, after reflection, by the first major surface or a surface of at least one other microstructure; a release layer disposed over the plurality of microstructures, the release layer comprising a metal layer or a doped semiconductor layer; a (co)polymer layer disposed on a major surface of the release layer opposite the first microstructured film; a multilayer optical film disposed on a major surface of the (co)polymer layer opposite the release layer; and a second microstructured film adjacent to a major surface of the multilayer optical film opposite the (co)polymer layer, the second microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom, at least some of the plurality of microstructures each having a surface with a slope such that light incident perpendicular to the first major surface of the second microstructured film is blocked, after reflection, by the first major surface or by a surface of at least one other microstructure; An article comprising: the multilayer optical film is composed of one or more alternating first and second inorganic optical layers that cooperate to reflect and absorb light incident normally to the first major surface of the second microstructured film, and reflect and absorb an average of 50, 60, 70, 80, 90, or 95% or more of incident ultraviolet light over a wavelength reflection band of at least 30 nanometers in the wavelength range of 190 nanometers to 400 nm.

14. 14. The article of claim 13, wherein the second microstructured film comprises cured polysiloxane, silicone-based thermoplastic polymer, polyethylene terephthalate (PET), cured urethane, thermoplastic urethane, cured (meth)acrylate, cured epoxy, cured vinyl ether, cured oxetane, cured thiol-acrylate, cured thiol-ene, PMMA, coPMMA, polyimide, cyclic olefin copolymer, cyclic olefin polymer, polycarbonate, polyethylene naphthalate (PEN), or a fluoropolymer (co)polymer comprising polymerized units derived from one or more monomers selected from tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, perfluoroalkoxyalkylene, or vinyl fluoride, or combinations thereof.

15. 15. The article of claim 13 or 14, wherein the second microstructured film comprises a cured urethane, a cured (meth)acrylate, coPMMA, PMMA, or a combination thereof, and optionally also comprises a UV absorber, a hindered amine light stabilizer, an antioxidant, or a combination thereof.

16. 15. The article of claim 13 or 14, wherein the second microstructured film comprises a cured polysiloxane, a silicone-based thermoplastic polymer, or a combination thereof.

17. The article of any one of claims 13-16, further comprising a tie layer, a substrate, or both, disposed on a major surface of the second microstructured film opposite the multilayer optical film.

18. a microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom, at least a portion of the plurality of microstructures each having a surface with a slope such that light incident perpendicularly to the first major surface of the microstructured film is blocked, after reflection, by the first major surface or by a surface of at least one other microstructure; a multilayer optical film disposed over the plurality of microstructures, the multilayer optical film being comprised of one or more alternating first and second inorganic optical layers that cooperate to reflect and absorb light incident normally to the first major surface of the microstructured film, and that reflects and absorbs an average of 50, 60, 70, 80, 90, or 95% or more of incident ultraviolet light over a wavelength reflection band of at least 30 nanometers in the wavelength range of 190 nanometers to 400 nm; a (co)polymer layer disposed on a major surface of the multilayer optical film opposite the microstructured film; Items including.

19. 20. The article of claim 18, further comprising a tie layer, a substrate, or both, disposed on the second major surface of the microstructured film.

20. 20. The article of claim 18 or 19, which transmits light normally incident on the first major surface of the second microstructured film and transmits an average of 50, 60, 70, 80, 90, or 95% or more of normally incident visible light in the wavelength range from greater than 400 nm to 700 nm.

21. The reduction in average transmittance of the article in the wavelength range of 400 nm to 700 nm is 425 megajoules per square meter (MJ / m ２ 21. The article of any one of claims 18-20, wherein the change in thickness of the article is less than 20%, less than 10%, less than 5%, or less than 1% after exposure to ultraviolet light.

22. a microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom, at least a portion of the plurality of microstructures each having a surface with a slope such that light incident perpendicularly to the first major surface of the microstructured film is blocked, after reflection, by the first major surface or by a surface of at least one other microstructure; a release layer disposed over the plurality of microstructures, the release layer comprising a metal layer or a doped semiconductor layer; a (co)polymer layer disposed on a major surface of the release layer opposite the microstructured film, the (co)polymer layer optionally further comprising an ultraviolet absorber, a hindered amine light stabilizer, an antioxidant, or a combination thereof; and A transfer article comprising:

23. 23. The transfer article of claim 22, wherein the (co)polymer layer is a first (co)polymer layer, and the transfer article further comprises a second (co)polymer layer disposed between the microstructured film and the release layer.

24. 1. A method for manufacturing an article, comprising: Providing a transfer article according to any one of claims 1 to 12, 22, or 23; applying a polymeric or crosslinkable material onto an outer major surface of the transfer article opposite the first microstructured film; curing the polymeric or crosslinkable material to form a second microstructured film having a first major surface and an opposite second major surface, the first major surface including a plurality of microstructures protruding therefrom, at least a portion of the plurality of microstructures each having a surface with a slope such that light incident normally on the first major surface of the second microstructured film is blocked after reflection by the first major surface or a surface of at least one other microstructure; and removing the release layer from the transfer article. A method comprising:

25. 25. The method of claim 24, wherein the transfer article is according to any one of claims 1 to 12, and further comprising removing the first (co)polymer layer after removing the release layer.

26. 26. The method of claim 24 or 25, further comprising applying a tie layer, a substrate, or both, onto the second major surface of the second microstructured film.

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