Layered assembly for providing a target transmitted color and a target reflected color

Abstract

A layered assembly is disclosed that includes a variable transmittance layer having opposing first and second sides, at least a first reflectance color-balancing layer disposed on the first side of the variable transmittance layer, and a transmittance color-balancing layer disposed on either the first side or the second side of the variable transmittance layer. The variable transmittance layer can be variable between a dark state and a bright state, and can have a dark state transmittance spectrum when in the dark state and a different bright state transmittance spectrum when in the bright state.

Description

[Technical Field]

[0001]

[0001] This disclosure relates generally to layered assemblies that are variable transmittance filters. The assemblies are also designed to exhibit optimal reflected color. The assemblies may include one or more coatings. [Background technology]

[0002]

[0002] Variable transmittance windows allow for selective filtering of electromagnetic radiation transmitted through the window. When incorporated into a vehicle, for example, as a sunroof or passenger window in a vehicle, the intensity and / or wavelength of electromagnetic radiation entering or exiting the vehicle through the variable transmittance window can be controlled to affect parameters such as light intensity within the vehicle.

[0003]

[0003] Some prior art in this field includes WO2018075005A1 or US20190248700A1 by Guardian Glass, which describes a gray coating article having an absorber layer and a low-E coating with low visible transmittance. Also, US20170267579A1 and US10247855 by Guardian Glass describe a gray heat-treatable coating article with low solar transmittance. US9588358 by SWITCH Materials Inc. describes an optical filter including a variable transmittance layer that addresses achieving a target transmission color.

[0004] Variable transmittance optical filters can employ various technologies to change visible light transmittance. Generally, such filters can be switched between a high light transmittance state (bleached or bright state) and a low light transmittance state (dark state) by the application, removal, or reduction of a stimulus, such as UV light, temperature, and / or voltage. Examples of technologies used in variable transmittance windows include photochromic, electrochromic, thermochromic, chemochromic, piezochromic, liquid crystal, or suspended particles. Photochromic materials can darken in response to light, e.g., UV light, and return to a bleached state when UV light is removed or reduced. Electrochromic materials can darken in response to the application of a voltage and return to a bleached state when the voltage is removed. Alternatively, electrochromic materials can darken in response to the application of a voltage of one polarity and bleach when a voltage of the opposite polarity is applied. Thermochromic materials can darken in proportion to increasing temperature. For example, the warmer the material, the darker it can become. Thermochromic materials can return to a faded state when the temperature drops. Chemochromic materials can darken or lighten in response to chemical changes in the environment, such as hydrogen gas, pH, or ion concentration. Piezoelectric materials can darken or lighten in response to changes in pressure or mechanical stress. Liquid crystal materials and suspended particle devices contain crystals or particles that change orientation in response to the application of voltage. In the absence of voltage, the crystals or particles are randomly oriented and scatter incident light, appearing opaque or transmitting little light. When a voltage is applied, the crystals or particles align with the electric field and can transmit light. When the variable transmittance optical filter includes an electrochromic embodiment, the variable transmittance optical filter can include an electrical connector for connecting the optical filter to a control circuit, which provides power to the optical filter to effect the electrochromic color change.

[0005] Depending on the nature of the variable transmittance optical filter and its application, further attenuation of transmitted light or solar energy may be desirable. When variable transmittance optical filters are used in vehicle, aircraft, or building windows, reducing or blocking infrared transmission may be useful for controlling heat rise, and reducing or blocking ultraviolet transmission may be useful for protecting occupants within the vehicle or building. When impact protection is desired, it may be useful to include laminated glass ("safety glass") in the window.

[0006]

[0006] Laminated glass having a neutral or gray transmitted color that simultaneously exhibits a neutral or gray reflected color is known—US20170267579A1 and WO2018075005A1 describe coating articles designed to achieve reflective coloring of gray glass sides (reflective tinting) in combination with low solar transmittance and / or low solar heat gain coefficient. However, these applications are silent about how color can be engineered in windows with variable light transmittance in the visible range.

[0007]

[0007] Laminated glass with tints or colors is known. US Pat. Nos. 4,244,997 and 2009 / 0303,581 describe laminated glass with a shade band, and US Pat. No. 7,655,314 describes laminated glass with an IR-blocking component and an interlayer containing a colorant that complements the yellow-green appearance of the IR-blocking component. However, these documents do not explain how color can be manipulated in windows with variable light transmittance in the visible range. Tinted glass with gray, bronze, or green tints can also be used to attenuate light transmitted through windows. Some tints may attenuate light nearly evenly across the visible spectrum, which can be effective in reducing overall glare, but if the components of the laminated glass itself are colored, they may not provide a color "correction" to a neutral tone, and additional color correction may be required.

[0008]

[0008] When laminated glass has a variable transmittance component, the degree of light transmission in one or both of the faded and dark states can be excessive or distorted. It is difficult to achieve a similarly neutral color for reflected light (e.g., the color of the laminated assembly as the eye observes the light passing through the assembly) while tandemly balancing the transmitted color (e.g., the color of the laminated assembly as the eye observes the reflected light) to a desired neutral color. Previously, color balancing for glazing products such as automotive sunroofs and architectural windows was achieved by modifying the chemical composition of the glass itself to provide the desired color or by including a tinted interlayer (e.g., PVB) between two panes of glass. Changing the color of a variable transmittance filter is much more difficult because the materials used to create the variable transmittance cannot be easily modified to a different color while maintaining all of the variable transmittance properties. For example, some variable transmittance filters are blue, which may be suitable for some applications but not others. Currently, the color of the entire product is determined by the color of the variable transmittance filter, even if that color is not considered the most desirable by the product's customer or potential customer. The inclusion of one or more additional visible light filters can further attenuate the transmitted light, but may also distort the color or exacerbate already distorted colors.

[0009]

[0009] US9588358 describes an optical filter including a variable transmittance layer having a first spectrum in a dark state and a second spectrum in a bleached state, and a color balancing layer having a third spectrum. When the spectrum of the dark state is combined with the spectrum of the color balancing layer, the resulting transmission spectrum approximates the target color of the dark state. Similarly, the spectrum of the bright state is combined with the color balancing layer so that the resulting transmission spectrum approximates the target color of the bright state. US9588358 does not provide any teaching or guidance on how to optimize the reflected color of the optical filter. Additional light-attenuating layers may be included in the stack, and the optical filter may comprise part of a laminated glass. Summary of the Invention [Means for solving the problem]

[0010] In one aspect, the present invention relates to a layered assembly including a variable transmittance layer having opposing first and second sides, at least a first reflectance color balancing layer disposed on the first side of the variable transmittance layer, and a transmittance color balancing layer disposed on either the first side or the second side of the variable transmittance layer. The layered assembly of the present invention may further include a second reflectance color balancing layer on a side of the variable transmittance layer opposite the first reflectance color balancing layer.

[0011] In another aspect, the present invention relates to a multilayer composition comprising a variable transmittance optical filter layer and one or more color balancing layers selected to combine with the color of the variable transmittance optical filter to achieve a desired transmission color and a desired reflection color. A laminated glass window with variable light transmission that provides a target (e.g., neutral) transmission color in a faded state, a dark state, or both the faded and dark states, while tandemly providing a target (e.g., neutral) reflection color in a faded state, a dark state, or both the faded and dark states, represents a useful addition to the art and can be used in automotive windows (windshields, sunroofs, moonroofs, windows, backlights, sidelights, etc.), other transportation applications such as trains and buses, architectural applications, eyewear and ophthalmic devices or applications, etc.

[0012]

[0012] Other aspects are further disclosed and claimed herein.

[0013]

[0013] These and other features will become more apparent from the following description taken in conjunction with the accompanying drawings, which are for illustrative purposes only and may not be drawn to relative proportions or scale unless otherwise indicated. [Brief explanation of the drawings]

[0014] [Figure 1]1 is a cross-sectional view of a stacked assembly according to one embodiment. [Figure 2]

[0015] FIG. 10 is a cross-sectional view of a stacked assembly according to another embodiment. [Figure 3]

[0016] FIG. 1 is an exploded schematic view of a laminated assembly depicting the reduced levels of light transmission and reflection with the addition of a color balancing layer. [Figure 4]

[0017] FIG. 1 shows a color balancing layer in the form of a layer-by-layer composite coating. [Figure 5]

[0018] FIG. 1 shows a color balancing layer in the form of a layer-by-layer composite coating. [Figure 6]

[0019] FIG. 1 shows a monotone L*a*b* color wheel with target transmission color ranges in the dark state of the variable transmittance layer. [Figure 7]

[0020] FIG. 1 shows a monotone L*a*b* color wheel with target transmission color ranges for the bright state of the variable transmittance layer. [Figure 8]

[0021] FIG. 1 shows a monotone L*a*b* color wheel with target reflected color range in the dark state with a variable transmittance layer. [Figure 9]

[0022] FIG. 1 shows a monotone L*a*b* color wheel with target reflected color range in the bright state with a variable transmittance layer. DETAILED DESCRIPTION OF THE INVENTION

[0015]

[0023] Thus, in one aspect, the present invention relates to a layered assembly including a variable transmittance layer having opposing first and second sides, a reflectance color-balancing layer disposed on the first side of the variable transmittance layer, and a transmittance color-balancing layer disposed on either the first side or the second side of the variable transmittance layer. The layered assembly may further include a second reflectance color-balancing layer on the side of the variable transmittance layer opposite the first reflectance color-balancing layer. At least one of the first reflectance color-balancing layer and the transmittance color-balancing layer may include, for example, a pigmented polymer or multiple pigmented films.

[0016]

[0024] As defined herein, descriptions of transmittance and reflectance are intended to encompass transmittance and reflectance in either or both directions. Those skilled in the art will readily understand that it is not necessary for the practice of the present invention for a layered assembly to meet every portion of the description of the present invention from both directions.

[0017]

[0025] In one embodiment, the layered assembly of the present invention can further include a first polymer layer, such as PVB, on a first side of the layered assembly and a second polymer layer, such as PVB, on a second side of the layered assembly. In another embodiment, at least one of the first and second polymer layers comprises a PVB coating on PET. In a further embodiment, the layered assembly can further include an IR blocking layer.

[0018]

[0026] In another aspect, the layered assembly of the present invention may include a variable transmittance layer, a reflectance color balancing layer, and a polymer-based layer onto which the transmittance color balancing layer is laminated, and the reflectance color balancing layer may be immediately adjacent to the polymer-based layer.

[0019]

[0027] The layered assembly may optionally further comprise glass sheets or other rigid substrates laminated to opposing sides of the polymer-based layer or to opposing sides of the polymer-based layer, respectively.

[0020]

[0028] In various aspects, the variable transmittance layer may be variable between a dark state and a light state; the variable transmittance layer may have a dark state transmittance spectrum when in the dark state and a different light state transmittance spectrum when in the light state; the dark state transmittance spectrum and the transmittance spectrum of the color balance layer are selected such that, in response to visible light incident on the reflectance color balance layer when the variable transmittance layer is in the dark state, the transmitted color of the layered assembly approximates a target transmittance color and the reflected color of the layered assembly approximates a target reflected color; the variable transmittance layer is preferably not opaque.

[0021]

[0029] In another aspect, the variable transmittance layer is variable between a dark state and a bright state; the variable transmittance layer has a dark state transmittance spectrum when in the dark state and a different bright state transmittance spectrum when in the bright state; and the bright state transmittance spectrum and the transmittance spectrum of the color balance layer are selected such that, in response to visible light incident on the reflectance color balance layer when the variable transmittance layer is in the bright state, the transmitted color of the layered assembly approximates a target transmittance color and the reflected color of the layered assembly approximates a target reflected color.

[0022]

[0030] In certain embodiments, a reflectance color balancing layer may be present in or directly beneath the outer glass layer. In other embodiments, the target transmitted color and target reflected color are nearly neutral.

[0023]

[0031] Therefore, the target transmission color in the dark state is a * value and b from -20 to +3 * value, or a from -10 to +10 * value and b from -15 to +3 * value, or a from -4 to +4 * value and b from -7 to +3 * Furthermore, the target transmission color in the bright state can have an a value of -6 to +10. * value and b from -4 to +24 * value, or a from -5 to +8 * value and b from -3 to +18 * value, or a from -4 to +4 *value and b from -2 to +8 * According to the present invention, the target reflected color in the dark state can have an a value of -10 to +22. * value and b from -9 to +9 * value, or a from -4 to +19 * value and b from -5 to +6 * value, or a from -2 to +15 * value and b from -2 to +6 * Furthermore, the target reflected color in the bright state can have a value of -10 to +23. * value and b from -2 to +22 * value, or a from -6 to +18 * value and b from -2 to +16 * value, or a from -2 to +16 * value and b from -2 to +12 * It may have a value.

[0024]

[0032] In embodiments, the actual transmitted color compared to the color without the color balancing layer may have a Delta C of 20 or less, or 15 or less, or at least 5, or at least 10, and the actual reflected color compared to the color without the color balancing layer also has a Delta C of 20 or less, or 15 or less, or at least 5, or at least 10.

[0025]

[0033] In embodiments, the variable transmittance layer may be photochromic, electrochromic, thermochromic, liquid crystal material, chemochromic, piezochromic, suspended particle device, or any combination thereof. In embodiments, the variable transmittance layer comprises a photochromic / electrochromic switching material.

[0026]

[0034] In embodiments, the variable transmittance layer may be transitionable from a bleached state to a dark state upon exposure to electromagnetic radiation, and from the dark state to the bleached state upon application of a voltage.

[0027]

[0035] In embodiments, the layered assembly has an LT in the dark of less than about 1%, or less than about 2%, or less than about 5%, or less than about 10%. AIn embodiments, the layered assembly may have an LT of greater than about 5%, or greater than about 10%, or greater than about 15%, or greater than about 20% in the faded state. A In embodiments, the transmission haze through the layered assembly is 5% or less, 3% or less, 2% or less, or 1% or less.

[0028]

[0036] In some embodiments, at least one of the reflectance color-balancing layer and the transmittance color-balancing layer comprises an alternating laminate optical article including a polymer substrate and a composite coating, the composite coating including a first layer including a polyionic binder and a second layer including electromagnetic energy-absorbing insoluble particles, the first layer and the second layer each including a binding group component that together form a complementary binding group pair. In these embodiments, the composite coating has a total thickness of 5 nm to 300 nm. The first layer can be immediately adjacent to the polymer substrate on its first surface, and the second layer can be immediately adjacent to the first layer on its opposite surface. The electromagnetic energy-absorbing particles can include particulate pigments, the surface of which includes the binding group component of the second layer. In certain embodiments, the layered assembly may further include a second composite coating, the second composite coating including a first layer including a polyionic binder and a second layer including electromagnetic energy absorbing particles, the first layer of the second composite coating and the second layer of the second composite coating including complementary binding group pairs. In certain embodiments, the second layer of the first composite coating and the second layer of the second composite coating combine to provide an additive effect on the electromagnetic energy absorption properties and effectiveness of the electromagnetic energy absorbing optical product. In certain embodiments, the polymer substrate may be a polyethylene terephthalate film and may further include an ultraviolet absorbing material. In embodiments, the polymer substrate may be an undyed, transparent polyethylene terephthalate film. In embodiments, the electromagnetic energy absorbing particles of the second layer of the first composite coating and the electromagnetic energy absorbing particles of the second layer of the second composite coating each include a pigment. In an aspect, the electromagnetic energy absorbing particles of the second layer of the first composite coating and the electromagnetic energy absorbing particles of the second layer of the second composite coating provide an additive effect on the visually perceived color of the optical article. These layers may be formed from aqueous solutions.

[0029]

[0037] In one embodiment, a layered assembly of an alternating-layer optical product can be formed by a process comprising applying a first coating composition to a polymer substrate to form a first layer, the composition comprising a polyionic binder; and applying a second coating composition onto the first layer to form a second layer, the second coating composition comprising at least one pigment; wherein the first layer and the second layer each comprise a binding group component, which together form a complementary binding group pair. As previously mentioned, the electromagnetic energy absorbing particles can be pigments, and the surface of the pigment can comprise the binding group component of the second layer. Furthermore, at least one of the first coating composition and the second coating composition can be an aqueous dispersion or solution. The aforementioned applying steps a) and b) are typically carried out at ambient temperature and pressure.

[0030]

[0038] In another aspect, the present invention relates to a layered assembly including a variable transmittance layer having opposing first and second sides; a transmittance color-balancing layer disposed on the first side of the variable transmittance layer; a first reflectance color-balancing layer disposed on the first side of the variable transmittance layer and outboard of the transmittance color-balancing layer; and a second reflectance color-balancing layer disposed on the second side of the variable transmittance layer. The present invention may further include a polymer-based layer within which the variable transmittance layer, reflectance color-balancing layer, and transmittance color-balancing layer are laminated, and the reflectance color-balancing layer may be immediately adjacent to the polymer-based layer. The present invention may further include glass plates or other rigid substrates, such as polycarbonate, laminated to opposing sides of the polymer-based layer.

[0031]

[0039] In embodiments, the variable transmittance layer may be variable between a dark state and a bright state; the variable transmittance layer may have a dark state transmittance spectrum when in the dark state and a different bright state transmittance spectrum when in the bright state; and the transmission color of the layered assembly may vary between a -13 and +13 reflectance in response to visible light incident on the reflectance color balance layer when the variable transmittance layer is in the dark state. * value and b from -20 to +3 *The dark state transmittance spectrum and the transmittance spectrum of the color balancing layer are selected to have values.

[0032]

[0040] In another aspect, the variable transmittance layer can be variable between a dark state and a bright state; the variable transmittance layer can have a dark state transmittance spectrum when in the dark state and a different bright state transmittance spectrum when in the bright state; and the transmission color of the layered assembly can vary between a -6 and +10 reflectance in response to visible light incident on the reflectance color balance layer when the variable transmittance layer is in the bright state. * value and b from -4 to +24 * value, or a from -5 to +8 * value and b from -3 to +18 * value, or a from -4 to +4 * value and b from -2 to +8 * The bright state transmittance spectrum and the transmittance spectrum of the color balancing layer are selected to have values.

[0033]

[0041] In an embodiment, the transmission color is a range of -10 to +10. * value and b from -15 to +3 * The transmittance color may have a value of -4 to +4. * value and b from -7 to +3 * It may have a value.

[0034]

[0042] In embodiments, the variable transmittance layer may be variable between a non-opaque dark state and a bright state; the variable transmittance layer may have a dark state transmittance spectrum when in the dark state and a different bright state transmittance spectrum when in the bright state; and the transmission color of the layered assembly may vary between a -6 and +10 reflectance in response to visible light incident on the reflectance color balance layer when the variable transmittance layer is in the bright state. * value and b from -4 to +24 * The transparent color has a value of -5 to +8. * value and b from -3 to +18 * or the transmission color may have a value of -4 to +4. * value and b from -2 to +8 * The bright state transmittance spectrum and the transmittance spectrum of the color balancing layer are selected to have values.

[0035]

[0043] In embodiments, the variable transmittance layer may be variable between a non-opaque dark state and a bright state; the variable transmittance layer may have a dark state reflectance spectrum when in the dark state and a different bright state reflectance spectrum when in the bright state; and the reflected color of the layered assembly may vary between a -10 and +22 reflectance spectrum in response to visible light incident on the reflectance color balance layer when the variable transmittance layer is in the dark state. * value and b from -9 to +9 * A value of -4 to +19, or a reflection color * value and b from -5 to +6 * A value of -2 to +15, or a reflection color * value and b from -2 to +6 * The dark state reflectance spectrum and the reflectance spectrum of the color balancing layer are selected to have values.

[0036]

[0044] In an embodiment of the invention, the variable transmittance layer is variable between a non-opaque dark state and a bright state; the variable transmittance layer has a dark state reflectance spectrum when in the dark state and a different bright state reflectance spectrum when in the bright state; and the reflected color of the layered assembly varies from -10 to +23 in response to visible light incident on the reflectance color balance layer when the variable transmittance layer is in the bright state. * value and b from -2 to +22 * A value of -6 to +18, or a reflection color * value and b from -2 to +16 * A value of -2 to +16, or a reflection color * value and b from -2 to +12 * The bright state reflectance spectrum and the reflectance spectrum of the color balancing layer are selected to have values.

[0037]

[0045] Thus, in one aspect, the present invention relates to a layered assembly including a variable transmittance layer having opposing first and second sides, a reflectance color balancing layer disposed on the first side of the variable transmittance layer, and a transmittance color balancing layer disposed on either the first side or the second side of the variable transmittance layer. It is important to note that in certain embodiments, the variable transmittance layer may be deposited directly onto glass, such as the exterior glass of a vehicle. In this case, both the reflectance color balancing layer and the transmittance color balancing layer may be on the same side of the variable transmittance layer, preferably with the reflectance color balancing layer closest to the viewer, i.e., the driver.

[0038]

[0046] In one aspect, the present invention provides a multilayer composition comprising a variable transmittance layer, which may be a variable transmittance optical filter having at least a first transmission spectrum and a first reflection spectrum in a dark state and a second transmission spectrum and a second reflection spectrum in a faded state, and one or more color balancing layers, each having a transmission and reflection spectrum, each spectrum including a UV portion, a visible portion, and an IR portion; and the layer spectra are combined to provide a color of the multilayer composition that approximates the target transmission color in the dark state and the target reflection color in the dark state and the target reflection color in the bright state. In another aspect, the present invention provides a laminated glass comprising such a multilayer composition. In another aspect, the present invention provides an automotive or architectural glazing comprising the multilayer composition or the laminated glass. The multilayer composition may further comprise one or more light-attenuating layers, a UV-blocking layer, and an IR-blocking layer.

[0039] Definitions and Terminology

[0047] When light or energy is said to be "blocked," whether visible, UV, or IR, the term is intended to encompass light that is absorbed and light that is reflected, as well as any light within the wavelength range that is scattered by the optical product.

[0040]

[0048] Spectrum refers to the characteristic light transmission or reflection of a multilayer composition or its components, according to various aspects and embodiments. The transmitted light will typically have UV, visible, and IR components or portions. The spectra from the various layers can be mathematically combined, and the visible region of the resulting spectrum can be expressed in terms of color (e.g., L * a * b * It can be described using color values, RGB, etc.

[0041]

[0049] A variable transmittance layer, or variable transmittance optical filter, is a layer that can adjust or change the transmittance of any wavelength of electromagnetic radiation, whether UV, visible, or infrared, as a function of, for example, the material or a physical stimulus. The physical stimulus may be mechanical, pressure, electromagnetic radiation, heat, chemical, or electrical.

[0042]

[0050] Thus, as mentioned above, these layers or filters can employ various techniques to change transmittance. Generally, such filters can be switched between a high light transmittance state (bleached or bright state) and a low light transmittance state (dark state) by the application, removal, or reduction of stimuli such as UV light, temperature, and / or voltage. Examples of technologies used for variable transmittance windows include photochromic, electrochromic, polarimetric, thermochromic, chemochromic, liquid crystal, or suspended particle technology. Some photochromic materials darken in response to light, e.g., UV light, and return to a bleached state when UV light is removed or reduced. Some electrochromic materials darken in response to the application of a voltage and return to a bleached state when the voltage is removed. Alternatively, some electrochromic materials darken in response to the application of a voltage of one polarity and fade when a voltage of the opposite polarity is applied. Some thermochromic materials darken in proportion to increasing temperature. For example, the warmer the material, the darker it becomes. Thermochromic materials may revert to a bleached state when the temperature drops. Liquid crystal material and suspended particle devices contain crystals or particles that change orientation in response to the application of a voltage. In the absence of a voltage, the liquid crystal molecules or particles are randomly oriented and absorb or scatter incident light, appearing darker, brighter, or opaque, or transmitting little light. When a voltage is applied, the liquid crystal molecules or particles align with the electric field, and light may be absorbed or transmitted to different degrees. When the variable transmittance optical filter includes an electrochromic embodiment, the variable transmittance optical filter may include an electrical connector for connecting the optical filter to a control circuit, which provides power to the optical filter to effect the electrochromic color change.

[0043]

[0051] Thus, a variable transmittance optical filter or layer is an optical filter that has different states of transmittance or transmission such that the transmission can be one state (e.g., a dark state) under one set of conditions and a second state (e.g., a bright state) under another set of conditions. Intermediate states are also possible. Some examples of variable transmittance filters include electrochromic optical filters, photochromic optical filters, photochromic / electrochromic optical filters, suspended particle devices, liquid crystal devices, thermochromic optical filters, and others, as described in the prior art. According to some embodiments herein, the variable transmittance optical filter is based on a photochromic / electrochromic material that darkens when exposed to electromagnetic radiation (“light”) and bleaches when a voltage is applied to the material. Some photochromic / electrochromic materials can also bleach when light of a selected wavelength is incident on the switching material.

[0044]

[0052] The variable transmittance optical layers will typically provide the layered assembly with a desired or target transmission color that is nearly neutral. For example, the target transmission color of the layered assembly in the dark state may range from -13 to +13. * value and b from -20 to +3 * value, or a from -10 to +10 * value and b from -15 to +3 * value, or a from -4 to +4 * value and b from -7 to +3 * Furthermore, the target transmission color for the bright state can have a value of -6 to +10. * value and b from -4 to +24 * value, or a from -5 to +8 * value and b from -3 to +18 * value, or a from -4 to +4 * value and b from -2 to +8 * It may have a value.

[0045]

[0053] When the variable transmittance layer of the present invention, or other layers described herein, such as color balancing layers, are described as having opposing first and second sides, the numbering of these sides may be entirely arbitrary unless the context clearly requires otherwise.

[0046]

[0054] The one or more color balancing layers of the present invention each have a transmission spectrum and a reflection spectrum. These color balancing layers are intended to balance the color of the layered assembly, such as the color resulting from the variable transmittance layer. These color balancing layers may be, for example, polymeric films such as PVB, or, when present in the assembly or stack of the present invention, may be deposited on or incorporated into a glass plate or polymeric film. Thus, the reflectance color balancing layer desirably affects the reflected color of the layered assembly, while the transmittance color balancing layer desirably affects the transmitted color of the layered assembly of the present invention, as well as the color of an object illuminated by light passing through the variable transmittance layer. It is understood that the reflectance color balancing layer will be most effective in desirably affecting the reflected color of the layered assembly of the present invention when positioned closest to the viewer.

[0047]

[0055] According to the present invention, the layered assembly of the present invention has a * value and b from -9 to +9 * value, or a from -4 to +19 * value and b from -5 to +6 * value, or a from -2 to +15 * value and b from -2 to +6 * The target reflected color in the dark state may further be indicated by a value of -10 to +23. * value and b from -2 to +22 * value, or a from -6 to +18 * value and b from -2 to +16 * value, or a from -2 to +16 * value and b from -2 to +12 * It may have a value.

[0048]

[0056] In another embodiment, the actual transmitted color compared to the target transmitted color may have a delta C of 20 or less, and the actual reflected color compared to the target transmitted color may also have a delta C of 20 or less.

[0049]

[0057] In another embodiment of the invention, the layered assembly has an LT in the dark of less than about 1%, or less than about 2%, or less than about 5%, or less than about 10%. A Additionally, the layered assembly may have greater than about 5%, or greater than about 10%, or greater than about 15%, or greater than about 20% LT in the faded state. A In another embodiment, the transmission haze through the layered assembly can be 5% or less, 3% or less, 2% or less, or 1% or less.

[0050]

[0058] With respect to the variable transmittance layers described, it will be understood that these typically have at least a first and a second side, with the color balancing layer advantageously disposed on one or the other of these sides. Thus, the reflectance color balancing layer and the transmittance color balancing layer can be on opposite sides of the variable transmittance layer or on the same side. When the color balancing layer is on the same side of the variable transmittance layer, both can be immediately adjacent to the variable transmittance layer. However, those skilled in the art will understand that the reflectance color balancing layer is most effective when closest to the viewer, which may mean that it is disposed on or functionally adjacent to the transmittance color balancing layer.

[0051]

[0059] As used herein, the term "reflectance color balancing layer" means a layer or element that causes the reflected visible light of a layered assembly to approach a target reflected color or spectrum, e.g., a target reflected color in the dark state ranging from -10 to +22. * value and b from -9 to +9 * value, or a from -4 to +19 * value and b from -5 to +6 * value, or a from -2 to +15 * value and b from -2 to +6 * The target reflected color in bright conditions has an a value of -10 to +23. *value and b from -2 to +22 * value, or a from -6 to +18 * value and b from -2 to +16 * value, or a from -2 to +16 * value and b from -2 to +12 * It has a value.

[0052]

[0060] As used herein, the term "transmittance color balancing layer" means a layer or element that causes transmitted visible light to meet a target transmitted color or spectrum, e.g., a target transmitted color in the dark state is a range of -13 to +13. * value and b from -20 to +3 * value, or a from -10 to +10 * value and b from -15 to +3 * value, or a from -4 to +4 * value and b from -7 to +3 * The target transmittance color in the bright state is a value of -6 to +10. * value and b from -4 to +24 * value, or a from -5 to +8 * value and b from -3 to +18 * value, or a from -4 to +4 * value and b from -2 to +8 * It has a value.

[0053]

[0061] Those skilled in the art will understand that when considering how to color balance transmittance, one should consider both the view through the glazing, for example from the inside to the outside of the vehicle, and the effect of color on the transmitted light through the glazing.

[0054]

[0062] The term "stack" or layered assembly can be used generally to describe two or more light-transmitting or light-reflecting layers (glass, interlayers, color-balancing layers, light-attenuating layers, layer-by-layer coatings, adhesive layers, etc.), or more specifically, the layered assemblies of the present invention. A stack can be characterized by a color, spectrum, transmitted light, reflected light, or the difference in color or transmitted or reflected light of the stack relative to a target (LT A , L * a * b* , Delta C, Delta E, etc.).

[0055]

[0063] As used herein, the term "mil" refers to a unit of length of 1 / 1000 inch (.001). One mil is approximately 25 microns, and such dimensions may be used to describe the thickness of optical filters or components of optical filters according to some embodiments of the present invention. Those skilled in the art can interconvert dimensions in "mils" to microns and vice versa.

[0056]

[0064] As used herein, "about" when referring to a measurable value such as an amount, duration, and the like, is meant to encompass variations of ±20% or ±10%, more preferably ±5%, even more preferably ±1%, and even more preferably ±0.1% from the specified value, as such variations are appropriate for practicing the disclosed methods.

[0057]

[0065] The color of the laminated glass comprising the switching material, layer, multilayer composition or multilayer composition is determined by the color value L, as known in the art. * a * and b * Visible Light Transmission LT (Illuminant D65 compliant, 10 degree observer) and / or as known in the art A (Light Transmission, Illuminant A, 2-degree observer) A and L * a * b * The value can be measured according to the SAEJ1796 standard. * a * The L b color space provides a means for describing observed colors. * defines the brightness with 0 being black and 100 being white, and a * defines the green or red level (where +a * Value is red, -a * value is green), b * defines the blue or yellow level (where +b * Values ​​are yellow, -b* For neutral gray, C = (a 2 +b 2 ) 1 / 2 In this case, C (or C * ab) By calculating the value of L * It can represent transmitted or reflected color independently of the

[0058]

[0066] To describe the scalar relationship between the target color and the achieved color (by combining one or more layers with a variable transmittance optical filter), ΔC (Delta C) is calculated.

[0059] Delta C = C of stack * ab -Goal C * ab

[0067] To describe the vector relationship between the target color and the achieved color, ΔE (Delta E) is calculated.

[0060] Delta E * ab =[(Delta L * ) 2 +(Delta a * ) 2 +(Delta b * ) 2 ] 1 / 2

[0068] As an example of the range of C values ​​that are considered neutral, transmission spectra from 10 commercial sources of "gray" glass were obtained (LT A (normalized for 1.6), showing a maximum Cmax of 4.4 and an average Cavg of 1.6, while the LT across the visible spectrum A The other L across the range of grey tones decreases in a similar manner. * a * b * The values ​​are explained below. Thus, a neutral color is an "achromatic color" (a color with similar or nearly similar LT values ​​across the visible range). ATwo or more spectra may be described as "complementary" if, when combined in the visible portion of the spectrum, they provide an achromatic spectrum (a "neutral color"). A neutral color, when judged "by the eye," is not substantially yellow / blue or red / green. The lower the Delta C or Delta E value, the smaller the color difference between the target color and the stack color. Generally, a stack approximating a target color will have a Delta C of about 0 to about 20, or any amount therebetween, or a Delta E of about 0, or any amount therebetween. For clarity, a range of about 0 to about 20, or any amount therebetween, includes about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19, or any amount therebetween.

[0061]

[0069] Directional terms, such as "upper," "lower," "upward," "downward," "vertical," "lateral," "inboard," and "outboard," are used in this disclosure to provide relative references only and are not intended to suggest limitations on how an item may be positioned during use, attached to an assembly, or positioned relative to an environment. Additionally, as used in this disclosure, "couple" and variations thereof, such as "coupled," "couples," and "coupling," are intended to include indirect and direct connections unless otherwise indicated. For example, if a first item is coupled to a second item, the coupling may be by a direct connection or by an indirect connection via another item.

[0062]

[0070] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In the event that a definition set forth in this section contradicts or conflicts with a definition set forth in a document incorporated herein by reference, the definition set forth herein shall take precedence over the definition incorporated herein by reference. [Example]

[0063]

[0071] Generally, windows including variable transmittance components (e.g., variable transmittance optical filters, layers, or elements, or variable transmittance laminated glass, etc.) can separate an interior space from an exterior space. Various layers and arrangements of layers can be contemplated depending on the window components. It may be desirable to change the observed (reflected) color or transmitted light color of a window to match or approximate a target color that differs from the color of the variable transmittance layer. For example, it may be desirable to match or approximate a target color to coordinate the appearance of the window with the exterior color of a building or vehicle, or to coordinate the appearance of the window with other components of the window, such as the frame. Figures 1-6 provide various configurations and arrangements of layers in multilayer compositions that can be used in such windows. In some embodiments, the relative positions of the layers can be described with reference to the variable transmittance layer and the incident light or space partially defined by the window.

[0064]

[0072] In one embodiment of the present invention, FIG. 1 illustrates a multilayer stack according to the present invention, including a laminated glass stack 100. The laminated stack includes two layers of glass 101 and 102, two layers of polyvinyl butyral (PVB) 103 and 104, and a variable transmittance layer 105. In this example, the PVB layer 103, which also functions as a color balancing layer, is located inboard of the variable transmittance layer 105. In this example, the PVB layer 103 would be located closer to the interior space if this were part of a window installed in a building or vehicle. Similarly, the PVB layer 104, which also functions as a color balancing layer in this example, is located outboard of the variable transmittance layer 105. The incident light from the light source 106 can be natural or simulated sunlight, or artificial light from any suitable source. The incident light can include the complete visible spectrum, significantly filter out light outside the visible spectrum, or the incident light can include a UV and / or infrared / near-infrared component.

[0065]

[0073] The variable transmittance layer 105 comprises a variable transmittance optical filter, which itself comprises a switching material (a switchable material). According to one embodiment, the variable transmittance layer 105 comprises a photochromic / electrochromic switching material. Examples of variable transmittance optical filters are described in US844107 and WO2013 / 106921, relevant portions of which are incorporated herein by reference in their entireties to the extent not inconsistent with this disclosure. Additional examples of switching materials are described in US8441707 and US10054835, relevant portions of which are incorporated herein by reference in their entireties to the extent not inconsistent with this disclosure. The variable transmittance layer 105 can be any color in the bleached or dark state. In some examples, the bleached state is substantially colorless or faintly colored (e.g., some switching materials including photochromic / electrochromic compounds are pale yellow in the bleached state), and the dark state is substantially colored (e.g., some switching materials including photochromic / electrochromic compounds are blue or blue-green, or pink / red or fuchsia in the dark state). Other switching materials or technologies, such as electrochromics, photochromics, suspended particle devices, or liquid crystal-based technologies, can also be used in place of the photochromic / electrochromic variable transmittance layer.

[0066]

[0074] According to one embodiment, the variable transmittance layer can be in the form of a sealed multilayer plastic film that can then be laminated between two layers of glass 101 and 102 using PVB layers 103 and 104. The variable transmittance can have a dark state, a light state, and states in between. The transmitted or reflected color of the variable transmittance layer itself may not be desirable for a particular application or customer. If a neutral color for the multilayer composition or laminated glass is desired, one or both of the PVB layers 103 and 104 can be tinted to vary the transmitted and / or reflected light.

[0067]

[0075] In this example, PVB layer 103 is a plum-colored PVB and PVB layer 104 is a light gray PVB. As described in some prior art examples, plum-colored PVB layer 103 can be used to color balance the example photochromic / electrochromic variable transmittance filter 105 by modifying the spectrum of light transmitted through the laminated assembly to match a more neutral target color in the dark and / or light states. In the prior art examples, the plum-colored PVB layer is placed outboard of the variable transmittance filter. This achieves the goal of providing a transmitted color closer to the target color, but does not take into account the reflected color of the laminated glass stack.

[0068]

[0076] Experiments have shown that the reflected color seen from the outside is dominated by the color of the first layer inside the glass, or in some cases, the color of the glass itself or a layer above the glass. Thus, in prior art examples, the reflected color is dominated by the plum-colored PVB because it is placed outboard of the variable transmittance layer. Customers may require a more neutral reflected color. Returning to Figure 1, an example laminated glass stack 100 is shown that provides color balance to the target transmitted color while also providing a more neutral reflected color when viewed from the outside.

[0069]

[0077] In the example shown in FIG. 1 , a plum-colored PVB layer 103 is positioned inboard of the variable transmittance layer 105, and a second light gray PVB layer 104 is positioned outboard of the variable transmittance layer 105, just inboard of the outer glass layer 101. While the transmitted color is the same regardless of the location of the plum-colored PVB layer 103 (outboard or inboard of the variable transmittance layer 105), in this example, the reflected color seen from the outside is significantly improved (i.e., more neutral) by placing the plum-colored PVB layer 103 inboard of the variable transmittance layer 105 and including the light gray PVB layer 104 outboard of layer 105. The light gray PVB layer used in this example may be a 15-mil thick PVB with a visible light transmittance of approximately 71%. The light gray PVB layer 104 reduces the overall amount of light transmittance through the stack, but some customers may desire an overall darker stack. Alternatively, the stack can be made lighter by, for example, reducing the amount of switching material in the variable transmittance layer 105 and / or increasing the light transmittance (i.e., making it lighter) of the plum-colored PVB layer 103, or by other means.

[0070]

[0078] FIG. 2 shows a laminated glass stack 200 having a plum-colored PVB layer 103 on the outboard side of the variable transmittance layer 105 and a light gray PVB layer 104 on the inboard side of the variable transmittance layer 105. The plum-colored PVB 103 serves the same function of color balancing the transmitted color of the variable transmittance layer 105 in the dark and / or light states. Two gray PVB layers are used to achieve the desired reflected color. To make the reflected color of the glass laminate 200 appear more neutral from the inside, a light gray PVB layer 104 is placed on the inboard side of the variable transmittance layer 105. To make the reflected color of the glass laminate 200 appear more neutral from the outside, a dark gray PVB layer 201 is placed on the outboard side of the plum-colored PVB layer 103. Because the dark gray PVB layer 201 is the first layer on the inside of the glass layer 101, it has the greatest impact on the reflectivity of the stack when viewed from the outside. In this example, a neutral reflected color is desired, and the additional dark gray PVB layer 201 helps achieve this goal. The dark gray PVB layer 201 can be, for example, a 15 mil thick PVB layer with a visible light transmittance of approximately 43%.

[0071]

[0079] Figure 3 shows how reflected light is affected by the various layers of the laminated glass stack 200 according to this example. The width of the arrows in Figure 3 represents light intensity. The largest portion of the reflected light comes from the layer directly below the outer glass layer 101. In this case, the dark gray PVB layer 201 reflects a neutral color and is the layer closest to the glass, so the neutral color reflected by this layer tends to dominate the overall color of the reflected light. As the light travels deeper into the stack, less light is reflected from subsequent layers because the light has already been attenuated by the dark gray PVB layer 201. Furthermore, the reflected light is further attenuated because it must also pass back through the dark gray layer 201 to reach the outside. For example, the reflection from the plum-colored PVB layer 103 is very reduced, having very little effect on the reflected color, and the reflected light from the variable transmission layer 105 is very reduced. The reflection from the PVB layer 104, which is inboard of the variable transmission layer 105, is almost negligible. Note that in this example, the light grey PVB layer 104 dominates the reflection of light from inside the multi-layer stack 201, so the reflected light from inside the vehicle or building will also be more neutral.

[0072]

[0080] Although a specific PVB interlayer is described, a variety of interlayer materials can be used. The interlayer is preferably colored to achieve the desired transmittance and reflectance.

[0073]

[0081] When the interlayer comprises PVB, the PVB resin can be produced by a known acetalization process in which polyvinyl alcohol ("PVOH") is reacted with butyraldehyde in the presence of an acid catalyst, followed by isolation, stabilization, and drying of the resin. Such acetalization processes are disclosed, for example, in U.S. Pat. Nos. 2,282,057 and 2,282,026, and in "Vinyl Acetal Polymers," Encyclopedia of Polymer Science & Technology, 3rd Edition, Vol. 8, pp. 381-399, BEWade (2003), the entire disclosures of which are incorporated herein by reference. Resins are commercially available in various forms, for example, as Butvar® Resin from Solutia Inc., a wholly owned subsidiary of Eastman Chemical Company.

[0074]

[0082] As used herein, the residual hydroxyl content in PVB (calculated as weight percent vinyl alcohol or weight percent PVOH) refers to the amount of hydroxyl groups remaining on the polymer chain after processing is complete. For example, PVB can be produced by hydrolyzing poly(vinyl acetate) to poly(vinyl alcohol) (PVOH) and then reacting the PVOH with butyraldehyde. The process of hydrolyzing polyvinyl acetate typically does not convert all of the acetate side groups to hydroxyl groups. Furthermore, the reaction with butyraldehyde typically does not convert all of the hydroxyl groups to acetal groups. As a result, the finished PVB resin typically has residual acetate groups (as vinyl acetate groups) and residual hydroxyl groups (as vinyl hydroxyl groups) present as side chains on the polymer chain. As used herein, residual hydroxyl content and residual acetate content are measured on a weight percent (wt%) basis according to ASTM D1396.

[0075]

[0083] The PVB resins of the present disclosure typically have a molecular weight, as measured by size exclusion chromatography using low-angle laser light scattering, of greater than 50,000 daltons, or less than 500,000 daltons, or from about 50,000 to about 500,000 daltons, or from about 70,000 to about 500,000 daltons, or from about 100,000 to about 425,000 daltons. As used herein, the term "molecular weight" refers to weight average molecular weight.

[0076]

[0084] Various adhesion control agents ("ACAs") can be used in the interlayer of the present disclosure to control adhesion of the interlayer sheet to glass. In various embodiments of the interlayer of the present disclosure, the interlayer can include from about 0.003 to about 0.15 parts ACA per 100 parts resin; from about 0.01 to about 0.10 parts ACA per 100 parts resin; and from about 0.01 to about 0.04 parts ACA per 100 parts resin. Such ACAs include, but are not limited to, ACAs disclosed in U.S. Pat. No. 5,728,472 (the entire disclosure of which is incorporated herein by reference), residual sodium acetate, potassium acetate, magnesium bis(2-ethylbutyrate), and / or magnesium bis(2-ethylhexanoate).

[0077]

[0085] Other additives can be incorporated into the interlayer to improve its performance in the final product and to impart specific additional properties to the interlayer. Such additives include, but are not limited to, dyes, pigments, stabilizers (e.g., UV stabilizers), antioxidants, antiblocking agents, flame retardants, IR absorbers or blockers (e.g., indium tin oxide, antimony tin oxide, lanthanum hexaboride (LaB6), cesium tungsten oxide), processing aids, flow improvers, lubricants, impact modifiers, nucleating agents, heat stabilizers, UV absorbers, dispersants, surfactants, chelating agents, coupling agents, adhesives, primers, toughening additives, fillers, and the like, among other additives known to those skilled in the art.

[0078]

[0086] While the described embodiments refer to the polymer resin as PVB, those skilled in the art will understand that the polymer may be any polymer suitable for use in multilayer panels. Exemplary polymers include, but are not limited to, polyvinyl acetal (PVA) (such as poly(vinyl butyral) (PVB) or isomeric poly(vinyl isobutyral) (PVisoB)), polyurethane (PU), poly(ethylene-co-vinyl acetate) (EVA), polyvinyl chloride (PVC), poly(vinyl chloride-co-methacrylate), polyethylene, polyolefins, ethylene acrylate ester copolymers, poly(ethylene-co-butyl acrylate), silicone elastomers, epoxy resins, and acid copolymers such as ethylene / carboxylic acid copolymers and ionomers thereof, those derived from any of the aforementioned possible thermoplastic resins, combinations of the foregoing, and the like. PVB and its isomeric polymer PVisoB, polyvinyl chloride, and polyurethane are generally useful polymers for the interlayer, with PVB (and its isomeric polymers) being particularly preferred.

[0079]

[0087] In a further embodiment, the diffusive interlayer can be a multi-layer interlayer. For example, the multi-layer interlayer can be composed of PVB / PVisoB / PVB. Other examples include PVB / PVC / PVB or PVB / PU / PVB. Further examples include PVC / PVB / PVC or PU / PVB / PU. Alternatively, the skin and core layers can all be PVB, using the same or different starting PVB resins.

[0080]

[0088] At least one of the PVB layers will typically further comprise at least one colorant. Those skilled in the art will further understand that multiple PVB layers having different colors may be combined, or that a separate colored layer of plastic such as PET may be used in addition to or in place of the PVB.

[0081]

[0089] Alternatively, the PVB layer may be provided as an adhesive-coated plastic material that is applied to the plastic layer, as disclosed and claimed in U.S. Patent Nos. 6,455,141 and 9,248,628 (the disclosures of which are incorporated by reference in their entireties to the extent not inconsistent with this disclosure). In these embodiments, the adhesive-coated plastic material can be used, for example, in laminate assemblies.

[0082]

[0090] According to this embodiment, the coated plastic interlayer may be bonded to one of the glass sheets using a very thin (e.g., 0.25 to 5 mils) (0.006 mm to 0.127 mm) layer of adhesive that imparts a highly flat texture to the coated plastic interlayer. This flatness is preserved when this glass sheet-adhesive-plastic film composite is assembled into the final laminated glass structure using a second layer of adhesive and a second sheet of glass.

[0083]

[0091] This product comprises a first glass sheet having a smooth first surface; a first adhesive layer affixing a plastic film to the smooth surface of the first glass sheet. This first adhesive layer is thin, less than 5 mils (0.127 mm) thick. The plastic film is aligned and conformed to the smooth surface of the first glass sheet. The plastic film may carry an energy-reflective coating. The glass laminate is completed by a second adhesive layer bonding the plastic film to a second glass sheet. The energy-reflective layer may be on either side of the plastic film, but better results are achieved if it faces the thin adhesive layer and the first glass sheet.

[0084]

[0092] In another embodiment, this embodiment provides an intermediate to the final product just described, which is a plastic film bearing an energy blocking layer and a coating of adhesive of 5 mils (0.127 mm) or less on either side of the film, preferably on the side bearing the energy reflective layer, which provides a final product with improved corrosion resistance to the energy reflective layer, greater stability and product life.

[0085]

[0093] In a further aspect, a method for producing this intermediate is provided in which a plastic film coated with an energy-reflective layer is coated with a solution of adhesive (preferably over the energy-reflective coating). The solvent is then removed from the solution coating, leaving a layer of adhesive on the energy-reflective layer-bearing plastic film. The thickness of the adhesive solution coating can be predetermined to provide a final neat adhesive layer less than 5 mils (0.127 mm) thick.

[0086]

[0094] This process can be part of an overall laminated window manufacturing scheme in which an adhesive-coated reflective layer-carrying plastic film is adhered and conformed to the smooth surface of a first sheet of glass, a second layer of adhesive is applied, followed by a second sheet of glass, and the entire structure is laminated.

[0087]

[0095] Additionally, the adhesive, which may be PVB, once applied to the plastic layer can be grooved or textured to allow previously trapped air to escape from between the layers of the laminate assembly during the lamination process. This can allow for thinner adhesive layers while providing a final product with relatively few air bubbles and that is optically pleasing or substantially free of optical defects due to waviness of the plastic layer and / or wrinkling of the plastic sheet between the two PVB sheets.

[0088]

[0096] In an alternative embodiment, layer-by-layer techniques can be used to form one or more color balancing layers, as disclosed and claimed in, for example, U.S. Pat. No. 9,453,949 (incorporated herein by reference in its entirety). In this embodiment, the color balancing layer is formed as an optical article 10, now referring to FIGS. 4 and 5, comprising a polymer substrate 15 and a composite coating 20. The composite coating comprises a first layer 25 and a second layer 30. Preferably, the first layer 25 is immediately adjacent to the polymer substrate 20 on its first surface 28, and the second layer 30 is immediately adjacent to the first layer 25 on its opposite surface 32. The first layer 25 comprises a polyionic binder, and the second layer 30 comprises electromagnetic energy absorbing insoluble particles. Each layer 25 and 30 comprises a binding group component, and the binding group component of the first layer and the binding group component of the second layer constitute a complementary binding group pair. As used herein, the phrase "complementary binding group pair" means that a bonding interaction, such as electrostatic bonding, hydrogen bonding, van der Waals interactions, hydrophobic interactions, and / or chemically induced covalent bonding, exists between a binding group component of a first layer and a binding group component of a second layer of a composite coating. A "binding group component" is a chemical functional group that cooperates with a complementary binding group component to establish one or more of the above bonding interactions. The components are complementary in the sense that the bonding interaction occurs through their respective charges.

[0089]

[0097] The first layer 25 of the composite coating may comprise a polyionic binder, defined as a polymer containing multiple positively or negatively charged moieties along the polymer backbone. Positively charged polyionic binders are known as polycationic binders, while negatively charged ones are called polyanionic binders. Those skilled in the art will also appreciate that some polyionic binders can function as either polycationic or polyanionic binders, depending on factors such as pH, and are known as amphoteric. The charged moieties of the polyionic binder constitute the "binding group component" of the first layer.

[0090]

[0098] Examples of suitable polycationic binders include poly(allylamine hydrochloride), linear or branched poly(ethyleneimine), poly(diallyldimethylammonium chloride), polymers known as polyquaterniums or polyquats, and various copolymers thereof. Blends of polycationic binders are also contemplated by the present invention. Examples of suitable polyanionic binders include carboxylic acid-containing compounds such as poly(acrylic acid) and poly(methacrylic acid), and sulfonic acid-containing compounds such as poly(styrenesulfonic acid) and its various copolymers. Blends of polyanionic binders are also contemplated by the present invention. Both polycationic and polyanionic polyionic binders are generally known to those skilled in the art and are described, for example, in U.S. Published Patent Application No. US20140079884 to Krogman et al. Examples of suitable polyanionic binders include polyacrylic acid (PAA), poly(styrene sulfonic acid) (PSS), poly(vinyl alcohol) or poly(vinyl acetate) (PVA, PVAc), poly(vinyl sulfonic acid), carboxymethyl cellulose (CMC), polysilicic acid, poly(3,4-ethylenedioxythiophene) (PEDOT) and combinations thereof with other polymers (e.g., PEDOT:PSS), polysaccharides, and copolymers of the above. Other examples of suitable polyanionic binders include trimethoxysilane-functionalized PAA or PAH, or biomolecules such as DNA, RNA, or proteins. Examples of suitable polycationic binders include poly(diallyldimethylammonium chloride) (PDAC), chitosan, poly(allylamine hydrochloride) (PAH), polysaccharides, proteins, linear poly(ethyleneimine) (LPEI), branched poly(ethyleneimine) BPEI, and copolymers of the above. Examples of polyionic binders that can function as either polyanionic or polycationic binders include amphoteric polymers such as proteins, and copolymers of the polycationic and polyanionic binders described above.

[0091]

[0099] The concentration of the polyionic binder in the first layer can be selected based in part on the molecular weight of its charged repeat unit, but will typically be 0.1 mM to 100 mM, more preferably 0.5 mM to 50 mM, and most preferably 1 to 20 mM, based on the molecular weight of the charged repeat units comprising the first layer. Preferably, the polyionic binder is a polycationic binder, more preferably the polycationic binder is polyallylamine hydrochloride. Most preferably, the polyionic binder is soluble in water, and the composition used to form the first layer is an aqueous solution of the polyionic binder. In embodiments where the polyionic binder is a polycation and the first layer is formed from an aqueous solution, the pH of the aqueous solution is selected so that 5 to 95%, preferably 25 to 75%, and more preferably about half of the ionizable groups are protonated. Other optional components of the first layer include a biocide or shelf-life stabilizer.

[0092] [000100] The second layer 30 of the composite coating 20 may contain electromagnetic energy absorbing insoluble particles. The phrase "electromagnetic energy absorbing" means that the particles are intentionally selected as components of the optical product for their preferential absorption at a specific spectral wavelength(s) or wavelength range(s). The term "insoluble" reflects the fact that the particles are not substantially soluble in the composition used to form the second layer 30 but are present as particles in the optical product structure. The electromagnetic energy absorbing insoluble particles are preferably visible electromagnetic energy absorbers such as pigments, although insoluble particles that do not necessarily exhibit color, such as UV or IR absorbers or absorbers of various portions of the electromagnetic spectrum, can also be used. The electromagnetic energy absorbing particles are preferably present in the second layer in an amount of 30% to 60% by weight, based on the total weight of the second layer. To achieve the desired final electromagnetic energy absorption level, the second layer should be formed from a composition containing insoluble electromagnetic energy absorbing particles in an amount of 0.25 to 2% by weight, based on the total weight of the composition.

[0093] [000101] Pigments suitable for use as the electromagnetic energy absorbing insoluble particles in preferred embodiments of the second layer are particulate pigments, preferably having an average particle size of 5 to 300 nanometers, more preferably 10 to 50 nanometers, and are often referred to in the art as nanoparticle pigments. Even more preferably, the surface of the pigment contains the binding group component of the second layer. Suitable pigments are commercially available as colloidally stable aqueous dispersions from manufacturers such as Cabot, Clariant, DuPont, Dainippon, and DeGussa. Particularly suitable pigments include those available from Cabot Corporation under the Cab-O-Jet® trademark, such as 250C (cyan), 265M (magenta), 270Y (yellow), or 352K (black). To be stable in water as a colloidal dispersion, the pigment particle surface is typically treated to impart ionizable properties thereto, thereby providing the pigment with the desired binding group component on its surface. Commercially available pigments are sold in a variety of forms, such as suspensions, dispersions, etc., and it will be understood by those skilled in the art that care should be taken to evaluate the commercially available form of the pigment and modify it as necessary to ensure compatibility and performance with the optical product components, particularly in embodiments where the pigment surface also serves as the binding group component of the second layer.

[0094] [000102] It will also be understood by those skilled in the art that, although multiple pigments can be utilized in the second layer to achieve a particular hue or shade or color in the final optical product, when multiple pigments are used, they should be carefully selected to ensure compatibility and performance both with each other and with the optical product components. This is particularly relevant to embodiments in which the pigment surface also serves as the binding group component of the second layer, as, for example, particulate pigments may exhibit different surface charge densities due to different chemical modifications that can affect compatibility.

[0095] [000103] Preferably, the second layer of the composite coating further comprises a screening agent. A "screening agent" is defined as an additive that promotes uniform and reproducible deposition of the second layer through improved dispersion of the electromagnetic energy absorbing insoluble particles within the second layer by increasing ionic strength and reducing interparticle electrostatic repulsion. Screening agents are generally well known to those skilled in the art and are described, for example, in U.S. Published Patent Application No. US20140079884 to Krogman et al. Sodium chloride is typically the preferred screening agent based on component cost. The presence and concentration level of the screening agent can allow for higher loadings of the electromagnetic energy absorbing insoluble particles, as may be desired for optical products with low transmittance, and can also allow for customizable and carefully controllable loadings of the electromagnetic energy absorbing insoluble particles to achieve customizable and carefully controllable optical product levels.

[0096] [000104] These layered optical products may be comprised of a single pigment or a pigment blend as disclosed and claimed in U.S. Patent No. 9,817,166, the disclosure of which is incorporated herein by reference in its entirety. They may be used in place of or in addition to the pigmented PVB layers previously described.

[0097] [000105] In more specific embodiments, alternating stacked optical products exhibiting neutral reflection may be used, such as those disclosed and claimed in U.S. Pat. Nos. 10,613,261 and 10,627,555, the disclosures of which are incorporated herein by reference in their entireties.

[0098] [000106] In one embodiment, as disclosed in U.S. Pat. No. 10,613,261, these neutral reflecting alternating laminate optical products may include a composite coating having a plurality of bilayers of first and second layers, each comprising binding group components that together form complementary binding group pairs, the plurality of bilayers including: at least one bilayer a) comprised of a first pigment or pigment blend exhibiting a color reflectance value that is less than about 2.5; at least one bilayer b) comprised of a pigment or pigment blend that selectively blocks visible light in a wavelength range of interest; and at least one bilayer c) comprised of a second pigment or pigment blend exhibiting a color reflectance value that is less than about 2.5, wherein the optical product selectively blocks visible light in a wavelength range of interest while simultaneously exhibiting a color reflectance value that is less than about 2.5.

[0099] [000107] In this embodiment, the wavelength range of interest can be, for example, a 75 nm wavelength range, or a 50 nm wavelength range, or as described elsewhere. Similarly, in various embodiments, the wavelength range of interest can be 400 nm to 450 nm, or 600 nm to 650 nm, or 500 nm to 600 nm, or 525 nm to 575 nm, or as described elsewhere herein.

[0100] [000108] In this embodiment, the optical article may further include at least one bilayer d); deposited on the at least one bilayer c) and comprised of a pigment or pigment blend that, when formed into a bilayer, selectively blocks visible light in a wavelength range of interest and that may be the same as or different from the pigment or pigment blend of bilayer b); and at least one bilayer e) comprised of a neutral pigment or pigment blend that, when formed into a bilayer, exhibits a color reflectance value that is less than about 2.5 and that may be the same as or different from the pigment or pigment blend of bilayer a) or bilayer c).

[0101] [000109] In further embodiments of this aspect, the optical products may have a color reflectance value of less than about 2.0, or less than about 1.5, or as described elsewhere herein. As previously mentioned, the substrate of these optical products may include a polyethylene terephthalate film, and separately, the composite coating may have a total thickness of 5 nm to 1000 nm.

[0102] [000110] In another embodiment disclosed in U.S. Patent No. 10,627,555, these neutral-reflecting, alternating-layer, laminated optical articles can include a composite coating deposited on a substrate, which comprises at least one bilayer having a first layer and a second layer, each comprising a binding group component that together form a complementary binding group pair. At least one bilayer comprises a pigment blend including: a) at least two pigments that, when mixed together and formed into a bilayer, exhibit a color reflectance value that is less than about 2.5, and b) one or more pigments that, when mixed and formed into a bilayer, selectively block visible light in a desired wavelength range.

[0103] [000111] In this embodiment, the wavelength range of interest can also be a 75 nm wavelength range, or a 50 nm wavelength range, or 400 nm to 450 nm, or 600 nm to 650 nm, or 500 nm to 600 nm, or 525 nm to 575 nm, or a wavelength range described elsewhere herein.

[0104] [000112] In this embodiment, the at least one bilayer of the optical article of the present invention can include at least three bilayers, or as described elsewhere herein. In other embodiments, the color reflectance value of the optical article of the present invention can be less than about 2.0, or less than about 1.5, or as described elsewhere herein.

[0105] [000113] In this embodiment, the optical article can also include a polyethylene terephthalate film as a substrate. In another embodiment, the composite coating of the optical article of the present invention can have a total thickness of 5 nm to 1000 nm, or as described elsewhere herein.

[0106] [000114] When we say that these neutral-reflecting layer-by-layer coating optical articles or films, or individual bilayers or bilayers, selectively block visible light within a desired, defined, or predetermined wavelength range, we mean that the amount of light blocked within that wavelength range is greater than the amount of light blocked within another wavelength range of the same width within the visible light spectrum, i.e., from about 400 nm to 700 nm, or as otherwise described elsewhere herein. When we say that light is selectively blocked, the definition of "blocked" is intended to encompass light that is absorbed and reflected, as well as any light within the wavelength range that is scattered by the optical article. That is, all light that cannot be measured without being transmitted through the film or optical article is considered "blocked," whether the blocked light is absorbed, reflected, or scattered. Of course, one can also predetermine the wavelengths of interest and select pigments, for example, that absorb light within that preselected or predetermined wavelength range. Conversely, wavelength ranges of interest can be selected randomly, meaning that pigments can be tried for novelty or aesthetic effect and selected solely based on their effect on appearance and transmitted color, as long as the desired relatively neutral reflectance, as defined by color reflectance value, is also achieved.

[0107] [000115] The light measurements used in these embodiments, which are described in more detail in U.S. Pat. Nos. 10,613,261 and 10,627,555 (the relevant portions of which are incorporated herein by reference in their entirety to the extent not inconsistent with this disclosure), are based on the 1976 CIEL * a * b * It is determined using the color space CIEL. * a * b * is an opponent color system based on Richard Hunter's earlier (1942) system called L, a, b. * a * b *In color space, the three coordinates are the lightness (L * =0 is black, L * = 100 indicates diffuse white), the position between red and green (a * , negative values ​​indicate green, positive values ​​indicate red), and the position between yellow and blue (b * , negative values ​​indicate blue, positive values ​​indicate yellow).

[0108] [000116] Thus, these layered optical products can be used to replace one or both of the colored PVB layers mentioned above.

[0109] [000117] The performance of the laminated glass or multilayer compositions described herein is evaluated, for example, in VLT, LT A The performance of optical filters can be evaluated by conducting studies using standard techniques in the art, such as measuring color, haze, etc. WO 2010 / 142019 describes methods, apparatus, and techniques that can be used to evaluate the performance of optical filters.

[0110] [000118] Tables 1 and 2 below show color balance data for examples having multilayer glass laminate stacks similar to those shown in Figures 2 and 3, except that in these examples the plum-colored PVB layer 103 is a plum-colored PET layer. Table 1 shows the reflectance L when the variable transmittance layer 105 is in the dark state. * , a * , b * and Delta C. Table 2 shows the reflectance L when the variable transmittance layer 105 is in the bright state. * , a * , b * and Delta C. Table 3 shows the transmission L when the variable transmittance layer 105 is in the dark state. * , a * , b * Value, Delta C value, and LT A Table 4 shows the transmission L when the variable transmittance layer 105 is in the bright state. * , a * , b * Value, Delta C value, and LT AValues ​​are shown for various combinations of neutral gray PVB layers (layers 104 and 201). The percentage numbers shown in the top row are a measure of the amount of black pigment in layer 201 (first number) and layer 104 (second number), with a value of 100% corresponding approximately to the desired total loading of black pigment divided between layers 104 and 201. In all of the devices tested, the plum-colored PET layer 103 remains the same. With plum-colored PET included in the stack, the transmitted color is guaranteed to approximate the transmitted color target. Reflected Color L * , a * , b * Value and Delta C numerical data are shown for the stack as viewed from both the top (outside; most outboard position) and bottom (inside; most inboard position) of the stack.

[0111] [000119] In this example, both the target reflected color and the target transmitted color are * value and b * A perfectly neutral color has a value of 0. A perfect match between the target reflected and transmitted colors here would result in a Delta C of zero. However, as noted earlier, a Delta C between 0 and 20 represents a good approximation to the target color and will be acceptable for most applications. As can be seen from Table 1, even when variable transmittance filter 105 is in its dark (most colored) state, it is possible to achieve a Delta C value of less than 20 for the reflected color from the outside with the addition of gray PVB layer 201, and from the inside with the addition of gray PVB layer 104. Without these gray layers, the Delta C values ​​for reflected light from both the outside and inside would be much higher.

[0112] [000120] Note from Table 1 that, in general, the darker the gray (the higher the percentage of black pigment), the more effective it is at dominating the reflected color and reducing the Delta C value. For example, the Delta C of light reflected from a top stack with a gray PVB layer containing 55% total black pigment (PVB layer 201 in Figures 2 and 3) is 4.6, as shown in Example 1, which is higher than the Delta C value of 1.4 achieved by the same stack with a darker (90% black pigment) gray PVB layer in Example 4. Note the clear trend across Examples 1-4: the higher the percentage of black pigment in the gray PVB layer, the lower the Delta C value (more neutral). In all these examples, the color filters can be commercially available filters or custom filters designed to transmit and reflect specific spectrums to suit the desired application or to work more optimally with a specific variable transmittance filter.

[0113] [Table 1]

[0114] [000121] In Table 1, the Delta C values ​​for the light reflected from the bottom of the stack (inner, most inboard position) are also all less than 20, so the light reflected from the bottom also closely matches the neutral color target. The Delta C values ​​also show a similar trend of increasing as the lighter the gray layer used as the PVB layer 104 immediately next to the interior-facing glass (102). The 45% black pigment loading of Example 1 achieves a Delta C of 5.3, while the 10% black pigment loading of Example 4 achieves a Delta C of 16.3.

[0115] [000122] Because variable transmittance filters have both dark and bright states with different light transmittance and color characteristics, in some applications it may be important to ensure that the reflected color closely approximates the target color when the variable transmittance filter is in both the dark and bright states. Table 2 below shows the reflected L of the same four examples using the variable transmittance filter in the bright state. * a * b* The figures show the Delta C values. Delta C values ​​are generally higher when using the variable transmittance filter in the bright state, indicating that the reflected color in the bright state is slightly more difficult to balance than the reflected color in the dark state. However, nearly all Delta C values ​​are still below 20, which closely approximates the target. The only Delta C value slightly above 20 appears in the bottom reflection value of Example 4, which has an inboard gray PVB layer with 10% black pigment, suggesting that in this case the slightly darker gray PVB helps make the reflected light more neutral.

[0116] [Table 2]

[0117] [000123] Table 2 shows the results when the target transmitted light and the target reflected light are perfectly neutral gray, i.e., a * and b * The value of is zero, and a * b * The calculated delta C value is shown when the color wheel is expressed at its origin. * , b * Even if the value is not zero, a * b * It is possible to achieve a neutral appearance by setting the target colors for transmission and reflection near the origin of the color wheel. Different applications may prefer different regions of the color wheel closer to the neutral origin (e.g., a slight blue tint may be perceived as more acceptable than a slight orange tint), and may also have different targets for the dark versus light state of the variable transmittance filter layer 105.

[0118] [Table 3]

[0119] [000124] Tables 3 and 4 show that the plum-colored PET layer 103 is effective in neutralizing the transmission color of the same series of test fixtures (Examples 1-4), achieving the target transmission color for both the faded and dark states, while simultaneously providing the target reflected color for both the faded and dark states in tandem from both the top (outside; most outboard position) and bottom (inside; most inboard position) of the stack. When the variable transmittance filter 105 is in the dark state (Table 3), the Delta C value is 7 or less, indicating that the actual color closely matches the target color. Similarly, when the variable transmittance filter 105 is in the light state (Table 4), the Delta C value is less than 20, indicating that the actual color also closely matches the target color. In Examples 1, 2, and 4, the same loading of black pigment is present in the combined (100%) gray PVB layers 201 and 104, as is the plum-colored PET layer, and therefore the transmission color coordinates and LT are consistent whether the variable transmittance filter 105 is in the dark or light state. A Note that the values ​​are very similar.

[0120] [Table 4]

[0121] Example of target color range for light transmission from a multilayer stack [000125] FIG. 6 shows an example of a target transmission color range when the variable transmittance filter is in the dark state. * b * A color wheel 400 is shown. In this example, a circle 401 represents a range of colors from -13 to +13. * Value, -20 to +3 b * The circle 402 represents the a value, which is the preferred color range of the transmission color target. * Value, -15 to +3 b * The circle 403 represents the most desirable range, from -4 to +4. * value and b from -7 to +3 * Represents a value.

[0122] [000126] Similarly, FIG. 7 has an example of an exemplary target transmission color range when the variable transmittance filter is in the bright state. * b * A color wheel 500 is shown. In this example, the circle 501 represents a range of colors from -6 to +10. * Value, -4 to +24 b * The circle 502 represents the desired color range of the transmission color target, from -5 to +8. * Value, -3 to +18 b * The circle 503 represents the most preferable range, from -4 to +4. * value and b from -2 to +8 * Represents a value.

[0123] Example of target color range for light reflection from a multi-layer stack [000127] FIG. 8 shows an example of an exemplary target reflected color range when the variable transmittance filter is in the dark state. * b * Illustrates the color wheel 400. In this example, the circle 601 represents a range of colors from -10 to +22. * Value, b from -9 to +9 * The circle 602 represents the desired color range of the reflectance color target. * Value, b from -5 to +6 * The circle 603 represents the most desirable range, a value between -2 and +15. * value and b from -2 to +6 * Represents a value.

[0124] [000128] Similarly, FIG. 9 has an example of a target reflected color range when the variable transmittance filter is in the bright state. * b * Illustrates the color wheel 400. In this example, the circle 701 represents a range of colors from -10 to +23. * Value, b from -2 to +22 * The circle 702 represents the a value from -6 to +18, which is the preferred color range for the transmission color target. * Value, b from -2 to +16 *Circle 703 represents the most desirable range, from -2 to +16. * value and b from -2 to +12 * Represents a value.

[0125] [000129] In one example, a multilayer stack where a neutral color is desired in both transmission and reflection has a delta C of 20 or less when the target color falls within a preferred range for both transmission and reflection in the dark state, the light state, or both states. In another example, the multilayer stack has a delta C of 20 or less when the target color falls within a more preferred range for both transmission and reflection in the dark state, the light state, or both states. In another example, the multilayer stack has a delta C of 20 or less when the target color falls within a most preferred range for both transmission and reflection in the dark state, the light state, or both states.

[0126] [000130] The above examples describe a range of target colors for achieving more neutral transmitted and reflected light in a multilayer stack including variable transmittance filters. However, according to other embodiments, the target color for transmission and / or reflection need not necessarily be a neutral color. For example, a vehicle designer may want the reflected color to match the car's light-colored paint, or an architect may want to design a building to reflect light of a certain target color.

[0127] [000131] In these examples, the multilayer stack may include a color other than plum for the transmitted color balancing layer or a color other than gray for the reflected color balancing layer. The goal in these examples remains the same: to simultaneously achieve a delta C of 20 or less from the target transmitted color, whatever that may be, and a transmitted color that has a delta C of 20 or less from the target reflected color, whatever that may be for the particular application. While it may not be possible to achieve a delta C of 20 or less for all combinations of transmitted and reflected color targets, the same general principle applies: outboard of the variable transmittance filter, use a color layer that reflects the desired color as close to the outer glass pane as possible, and use a color layer below this layer to balance the transmitted color.

[0128] [000132] According to some examples, the multilayer stack has an LT in the dark state of less than about 1%, or less than about 2%, or less than about 5%, or less than about 10%. A According to some examples, the multilayer stack may have an LT of greater than about 4%, or greater than about 5%, or greater than about 10%, or greater than about 15%, or greater than about 20% in the bleached state. A may have:

[0129] [000133] According to some examples, the multilayer stack may have an LT concentration of about 1% to about 10% in the dark state, or any amount or range therebetween. A and in the faded state, LT may be about 5% to about 30%, or any amount or range therebetween. A For example, a multilayer composition or laminated glass may have an LT in which the dark state is smaller than the faded state. A LT in the dark or bleached state of about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 25, or 30%, or any amount or range therebetween, provided that A When the target transmitted and reflected colors are a neutral color "stack," the multilayer stacks according to various embodiments may have an L of about 40 to about 60, or any amount therebetween, in the bleached state. * It may have a value.

[0130] [000134] Lamination of a multilayer stack using PVB, such as that shown in Figures 1, 2, and 3, can be achieved using standard PVB lamination processes by applying heat and pressure to the stack (e.g., in an autoclave) for a period of time so that the PVB flows and bonds to both the variably transmitting layer 105 and the glass layers 101, 102. In this example, PVB layers are shown because using PVB is one of the most common materials for laminating glass, but other types of laminate layers can be used instead of PVB to bond the stack together. For example, ethylene vinyl acetate (EVA), thermoplastic polyurethane (TPU), SentryGlas® ionoplast polymer interlayers, and various pressure-sensitive adhesives (PSAs) are all examples of materials that can be used to bond glass to glass and film to glass, and can also be easily pigmented or dyed to impart colors suitable for practicing the present invention.

[0131] [000135] Also, color need not necessarily be contained solely in the PVB layer. It may alternatively or additionally be provided in the previously described layered optical products, typically deposited on a substrate such as PET. In a further embodiment, one or more colored PET layers, such as dyed PET films, may be used to color the layered assembly of the present invention.

[0132] [000136] Gray glass can be used in place of gray PVB, or more generally, colored glass can be used in place of colored polymer. For example, if glass layer 101 in FIG. 3 is replaced with gray glass instead of clear glass, gray PVB layer 201 is no longer needed or can be replaced with clear PVB. Gray glass can be used in place of gray PVB to achieve the desired reflected color. Similarly, if gray glass is used for glass layer 102, gray PVB layer 104 can also be replaced with a clear PVB layer.

[0133] Alternatively, the color-balancing layers for transmittance and reflectance in the stack can be constructed of materials other than PVB. In some examples, the color-balancing layer can be a polyethylene terephthalate (PET) layer adhered to the variable transmittance layer using a pressure-sensitive adhesive, and the entire stack can then be bonded to the glass using PVB or other materials. The pressure-sensitive adhesive layer itself can be colored, and in some examples of the variable transmittance layer, the PET substrate carrying the transparent conductive electrodes can also be colored. Other films, such as polyethylene naphthalate (PEN), polycarbonate, or thin glass films, are also possible. In some examples, some of these layers can be flexible or rigid. The reflective color-balancing gray layer can also be a coating on the outer glass layer, which can be applied by sputtering, chemical vapor deposition, spraying, slot die, painting, or other methods known in the art.

[0134] [000138] Low haze can be a desirable feature in some applications. In one example, the multilayer stack has a total transmission haze of about 5% or less, about 3% or less, about 2% or less, about 1.5% or less, or about 1% or less, or about 0-2%, or about 0.5-3%, or any amount or range therebetween.

[0135] [000139] The color balance layer may also contain UV absorbers and / or UV stabilizers to create UV cutoff wavelengths, or additional layers containing these materials may be added to the stack. For example, an adhesive layer such as PVB may have a UV-blocking additive (e.g., U.S. Pat. No. 6,627,318). In one example, a UV-blocking material is placed outboard of the variable transmittance filter layer 105 to prevent harmful UV from reaching the variable transmittance layer. For example, the gray PVB layer 201 may also contain a UV absorber to block UV below wavelengths of 380 nm or 400 nm.

[0136] [000140] One or more layers may also include an IR-blocking component. For example, a solar control film may be included in the multilayer stack or laminated glass. Examples of such films include US2004 / 0032658 and US4368945, the disclosures of which are incorporated herein by reference to the extent they do not conflict with this disclosure. Alternatively, the IR-blocking material may be incorporated into a layer of glass or an adhesive layer. The IR-blocking layer may reflect or absorb IR light. In one example, a layer of IR-reflective material is disposed on the outbound side of the variable transmittance layer 105 to keep the stack cooler by reflecting the heat energy in the IR out of the stack before it passes through other layers in the stack and is absorbed.

[0137] [000141] The multi-layer stack may also include a low-emissivity (low-E) coating. In one example, the low-E coating is disposed on one surface of the glass layer 102, inboard of the variable transmittance layer 105. This positioning of the layer helps prevent heat from radiating from the multi-layer stack into the vehicle or building.

[0138] Other embodiments [000142] It is contemplated that any embodiment discussed herein can be implemented or combined with any other embodiment, method, structure or aspect, and vice versa.

[0139] [000143] The present invention has been described with respect to one or more embodiments. However, it will be apparent to those skilled in the art that numerous variations and modifications are possible without departing from the scope of the invention, as defined in the claims. Thus, while various embodiments of the present invention are disclosed herein, many adaptations and modifications may be made within the scope of the invention, in accordance with the common general knowledge of those skilled in the art. Such modifications include the substitution of known equivalents for any aspect of the invention to achieve the same result in substantially the same way. Numerical ranges include the numbers defining the range. The terms "approximately" and "about," when used in conjunction with a value, mean ±10% of that value. The word "comprising" is used herein as an open-ended term substantially equivalent to the phrase "including, but not limited to," and the word "comprises" has a corresponding meaning. As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. The citation of a reference herein should not be construed as an admission that such reference is prior art to the present invention, or as to the contents or date of the reference. All publications are incorporated herein by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference and was fully set forth herein. The present invention includes all embodiments and variations substantially as described above with reference to the examples and drawings. The present invention includes the following embodiments. [1] i. a variable transmittance layer having opposing first and second sides; ii. at least a first reflectance color balancing layer disposed on a first side of the variable transmittance layer; iii. a transmittance color balance layer disposed on a first side or a second side of the variable transmittance layer; and A layered assembly comprising: [2] The layered assembly of [1], further comprising a second reflectance color balancing layer on a side of the variable transmittance layer opposite the first reflectance color balancing layer. [3] The layered assembly of [1] or [2], wherein at least one of the first reflectance color balance layer and the transmittance color balance layer comprises a plurality of colored films. [4] The layered assembly described in any one of [1] to [3], further comprising a first polymer layer on a first side of the layered assembly and a second polymer layer on a second side of the layered assembly. [5] The layered assembly of [4], wherein at least one of the first and second polymer layers comprises a PVB coating on PET. [6] The layered assembly according to any one of [1] to [5], wherein the layered assembly further comprises an IR blocking layer. [7] The layered assembly of any of [1] to [6], wherein at least the first reflectance color balance layer comprises a tinted PVB, and the layered assembly further comprises a rigid substrate laminated to the first reflectance color balance layer. [8] The layered assembly of [2], wherein both the first reflectance color balance layer and the second reflectance color balance layer comprise a tinted PVB, and the layered assembly further comprises a rigid substrate laminated to the first reflectance color balance layer and the second reflectance color balance layer, respectively. [9] The layered assembly of any one of [1] to [3], further comprising a polymer-based layer within which the variable transmittance layer, the reflectance color balance layer, and the transmittance color balance layer are laminated, the reflectance color balance layer being immediately adjacent to the polymer-based layer.

[10] The layered assembly according to [4], further comprising a hard substrate laminated to each of the first polymer layer and the second polymer layer.

[11] The layered assembly according to [9], further comprising a hard substrate laminated on each of the opposing sides of the polymer-based layer.

[12] i. The variable transmittance layer is variable between a dark state and a light state; ii. the variable transmittance layer has a dark state transmittance spectrum when in the dark state and a different bright state transmittance spectrum when in the bright state; iii. the dark state transmittance spectrum and the transmittance spectrum of the color balance layer are selected such that, in response to visible light incident on the reflectance color balance layer when the variable transmittance layer is in a dark state, the transmitted color of the layered assembly approximates a target transmittance color and the reflected color of the layered assembly approximates a target reflected color;

[12] The layered assembly according to any one of [1] to

[11] .

[13] i. The variable transmittance layer is variable between a dark state and a light state; ii. the variable transmittance layer has a dark state transmittance spectrum when in the dark state and a different bright state transmittance spectrum when in the bright state; iii. the bright state transmittance spectrum and the transmittance spectrum of the color balancing layer are selected such that, in response to visible light incident on the reflectance color balancing layer when the variable transmittance layer is in a bright state, the transmitted color of the layered assembly approximates a target transmittance color and the reflected color of the layered assembly approximates a target reflected color;

[12] The layered assembly according to any one of [1] to

[11] .

[14] The target transmission color in the dark state is a * value and b from -20 to +3 * value, or a from -10 to +10 * value and b from -15 to +3 * value, or a from -4 to +4 * value and b from -7 to +3 *

[12] The layered assembly according to

[12] , having a value.

[15] The target transmission color in the bright state is a * value and b from -4 to +24 * value, or a from -5 to +8 * value and b from -3 to +18 * value, or a from -4 to +4 * value and b from -2 to +8 *

[13] The layered assembly according to

[13] , having a value.

[16] The target reflection color in the dark state is -10 to +22 * value and b from -9 to +9 * value, or a from -4 to +19 * value and b from -5 to +6 * value, or a from -2 to +15 * value and b from -2 to +6 *

[12] . The layered assembly according to

[12] , having a value.

[17] The target reflection color in the bright state is a * value and b from -2 to +22 * value, or a from -6 to +18 * value and b from -2 to +16 * value, or a from -2 to +16 *value and b from -2 to +12 *

[13] The layered assembly according to

[13] , having a value.

[18] The layered assembly of any of

[12] to

[17] , wherein the difference in actual transmitted color compared to the transmittance of the layered assembly in the absence of the first reflectance color balance layer and the transmittance color balance layer has a Delta C of at least 5.

[19] The layered assembly of any of [1] to

[18] , wherein the variable transmittance layer comprises one or more of a photochromic material, an electrochromic material, a thermochromic material, a liquid crystal material, or a suspended particle device.

[20] The layered assembly according to any one of [1] to

[19] , wherein the variable transmittance layer is capable of transitioning from a bleached state to a dark state upon exposure to electromagnetic waves, and from the dark state to the bleached state upon application of a voltage.

[21] LT of less than about 1%, or less than about 2%, or less than about 5%, or less than about 10% in the dark A The layered assembly according to any one of [1] to

[20] ,

[22] More than about 5%, more than about 10%, more than about 15%, or more than about 20% LT in the faded state A The layered assembly according to any one of [1] to

[21] , comprising:

[23] The layered assembly of any of [1] to

[22] , wherein the transmission haze through the layered assembly is 5% or less, 3% or less, 2% or less, or 1% or less.

[24] At least one of the reflectance color balance layer and the transmittance color balance layer is a. a polymer substrate, and b. A composite coating comprising a first layer comprising a polyionic binder and a second layer comprising electromagnetic energy absorbing insoluble particles, wherein the first layer and the second layer each comprise binding group components that together form a complementary binding group pair. 23. The layered assembly according to any one of [1] to

[23] , comprising an alternating stacked optical product comprising:

[25] i. a variable transmittance layer having opposing first and second sides; ii. a transmittance color balancing layer disposed on a first side of the variable transmittance layer; iii. a first reflectance color balancing layer disposed on a first side of the variable transmittance layer and outboard of the transmittance color balancing layer; iv. a second reflectance color balance layer disposed on a second side of the variable transmittance layer; and A layered assembly comprising:

[26] i. The variable transmittance layer is variable between a dark state and a light state; ii. the variable transmittance layer has a dark state transmittance spectrum when in the dark state and a different bright state transmittance spectrum when in the bright state; iii. In response to visible light incident on the reflectance color balance layer when the variable transmittance layer is in a dark state, the transmitted color of the layered assembly is between -13 and +13. * value and b between -20 and +3 * the dark state transmittance spectrum and the transmittance spectrum of the color balance layer are selected so as to have values The layered assembly described in

[25] .

[27] i. The variable transmittance layer is variable between a dark state and a light state; ii. the variable transmittance layer has a dark state transmittance spectrum when in the dark state and a different bright state transmittance spectrum when in the bright state; iii. In response to visible light incident on the reflectance color balance layer when the variable transmittance layer is in a bright state, the transmitted color of the layered assembly is within a range of -6 to +10. * value and b from -4 to +24 * value, or a from -5 to +8 * value and b from -3 to +18 * value, or a from -4 to +4 * value and b from -2 to +8 * the bright state transmittance spectrum and the transmittance spectrum of the color balance layer are selected so as to have values The layered assembly described in

[25] .

[28] i. The variable transmittance layer is variable between a non-opaque dark state and a light state; ii. the variable transmittance layer has a dark state reflectance spectrum when in the dark state and a different bright state reflectance spectrum when in the bright state; iii. In response to visible light incident on the reflectance color balance layer when the variable transmittance layer is in a dark state, the reflected color of the layered assembly is between -10 and +22. * value and b from -9 to +9* the dark state reflectance spectrum and the reflectance spectrum of the color balance layer are selected so as to have values

[26] or

[27] .

[29] i. The variable transmittance layer is variable between a non-opaque dark state and a light state; ii. the variable transmittance layer has a dark state reflectance spectrum when in the dark state and a different bright state reflectance spectrum when in the bright state; iii. In response to visible light incident on the reflectance color balance layer when the variable transmittance layer is in a bright state, the reflected color of the layered assembly is between -10 and +23. * value and b from -2 to +22 * the bright state reflectance spectrum and the reflectance spectrum of the color balance layer are selected so as to have values

[26] or

[27] .

Claims

1. i. a variable transmittance layer having opposing first and second sides; ii. at least a first reflectance color balancing layer disposed on a first side of the variable transmittance layer; iii. a transmittance color balance layer disposed on the first side or the second side of the variable transmittance layer; A layered assembly comprising: The layered assembly further includes a second reflectance color balancing layer on a side of the variable transmittance layer opposite the first reflectance color balancing layer.

2. The layered assembly of claim 1 , wherein at least one of the first reflectance color balancing layer and the transmittance color balancing layer comprises a plurality of colored films.

3. The layered assembly of claim 1 or 2, further comprising a first polymer layer on a first side of the layered assembly and a second polymer layer on a second side of the layered assembly.

4. The layered assembly of claim 3 , wherein at least one of the first and second polymer layers comprises a PVB coating on PET.

5. The layered assembly of claim 1 , wherein the layered assembly further comprises an IR blocking layer.

6. 6. The layered assembly of claim 1, wherein at least the first reflectance color balance layer comprises pigmented PVB, and the layered assembly further comprises a rigid substrate laminated to the first reflectance color balance layer.

7. 10. The layered assembly of claim 1, wherein both the first reflectance and color balancing layer and the second reflectance and color balancing layer comprise pigmented PVB, and the layered assembly further comprises a rigid substrate laminated to the first reflectance and color balancing layer and the second reflectance and color balancing layer, respectively.

8. The layered assembly of claim 3 , further comprising a rigid substrate laminated to the first polymer layer and the second polymer layer, respectively.

9. i. the variable transmittance layer is variable between a dark state and a light state; ii. the variable transmittance layer has a dark state transmittance spectrum when in a dark state and a different bright state transmittance spectrum when in a bright state; iii. the dark state transmittance spectrum and the transmittance spectra of the first and second reflectance and transmittance color balancing layers are selected so that, in response to visible light incident on the reflectance color balancing layer when the variable transmittance layer is in a dark state, the transmitted color of the layered assembly approximates a target transmitted color and the reflected color of the layered assembly approximates a target reflected color; the target transmitted color in the dark state has an a* value of −13 to +13 and a b* value of −20 to +3; the target reflected color in the dark state has an a* value of −10 to +22 and a b* value of −9 to +9; A layered assembly according to any one of claims 1 to 8.

10. i. the variable transmittance layer is variable between a dark state and a light state; ii. the variable transmittance layer has a dark state transmittance spectrum when in a dark state and a different bright state transmittance spectrum when in a bright state; iii. the bright state transmittance spectrum and the transmittance spectra of the first and second reflectance and transmittance color balancing layers are selected so that, in response to visible light incident on the reflectance color balancing layer when the variable transmittance layer is in a bright state, the transmitted color of the layered assembly approximates a target transmitted color and the reflected color of the layered assembly approximates a target reflected color; the target transmitted color in a bright state has an a* value of −6 to +10 and a b* value of −4 to +24; the target reflected color in a bright state has an a* value of -10 to +23 and a b* value of -2 to +22; A layered assembly according to any one of claims 1 to 8.

11. 11. The layered assembly of claim 9 or 10, wherein the difference in actual transmitted color compared to the transmittance of the layered assembly without the first reflectance color balance layer and the transmittance color balance layer has a Delta C of at least 5.

12. 12. The layered assembly of claim 1, wherein the variable transmittance layer comprises one or more of a photochromic material, an electrochromic material, a thermochromic material, a liquid crystal material, or a suspended particle device.

13. 13. The layered assembly of claim 1, wherein the variable transmittance layer is transitionable from a bleached state to a dark state upon exposure to electromagnetic radiation, and from the dark state to the bleached state upon application of a voltage.

14. Less than 10% LT in the dark Ａ 14. The layered assembly of claim 1, wherein

15. More than 5% LT in faded state Ａ 15. The layered assembly of claim 1, wherein

16. 16. The layered assembly of claim 1, wherein the transmission haze through the layered assembly is 5% or less.

17. At least one of the reflectance color balance layer and the transmittance color balance layer is a. a polymer substrate, and b. A composite coating comprising a first layer comprising a polyionic binder and a second layer comprising electromagnetic energy absorbing insoluble particles, wherein the first layer and the second layer each comprise binding group components that together form a complementary binding group pair.

17. The layered assembly of claim 1, comprising an alternating stacked optical article comprising:

18. i. a variable transmittance layer having opposing first and second sides; ii. a transmittance color balancing layer disposed on a first side of the variable transmittance layer; a first reflectance color balancing layer disposed on a first side of the variable transmittance layer and outboard of the transmittance color balancing layer; iv. a second reflectance color balancing layer disposed on a second side of the variable transmittance layer; A layered assembly comprising:

19. i. the variable transmittance layer is variable between a dark state and a light state; ii. the variable transmittance layer has a dark state transmittance spectrum when in a dark state and a different bright state transmittance spectrum when in a bright state; iii. In response to visible light incident on the reflectance color balance layer when the variable transmittance layer is in a dark state, the transmitted color of the layered assembly varies from -13 to +13. ＊ value and b between -20 and +3 ＊ the dark-state transmittance spectrum and the transmittance spectra of the first and second reflectance color balance layers and the transmittance color balance layer are selected so as to have values 20. The layered assembly of claim 18.

20. i. the variable transmittance layer is variable between a dark state and a light state; ii. the variable transmittance layer has a dark state transmittance spectrum when in a dark state and a different bright state transmittance spectrum when in a bright state; iii. In response to visible light incident on the reflectance color balance layer when the variable transmittance layer is in a bright state, the transmitted color of the layered assembly varies from a ＊ value and b from -4 to +24 ＊ value, or a between -5 and +8 ＊ value and b from -3 to +18 ＊ value, or a between -4 and +4 ＊ value and b from -2 to +8 ＊ the bright state transmittance spectrum and the transmittance spectra of the first and second reflectance color balance layers and the transmittance color balance layer are selected so as to have a value 20. The layered assembly of claim 18.

21. i. the variable transmittance layer is variable between a non-opaque dark state and a light state; ii. the variable transmittance layer has a dark state reflectance spectrum when in a dark state and a different bright state reflectance spectrum when in a bright state; iii. In response to visible light incident on the reflectance color balance layer when the variable transmittance layer is in a dark state, the reflected color of the layered assembly is between -10 and +22. ＊ value and b from -9 to +9 ＊ the dark-state reflectance spectrum and the reflectance spectra of the first, second reflectance color balance layer and the transmittance color balance layer are selected so as to have values 21. A layered assembly according to claim 19 or 20.

22. i. the variable transmittance layer is variable between a non-opaque dark state and a light state; ii. the variable transmittance layer has a dark state reflectance spectrum when in a dark state and a different bright state reflectance spectrum when in a bright state; iii. In response to visible light incident on the reflectance color balance layer when the variable transmittance layer is in a bright state, the reflected color of the layered assembly is between -10 and +23. ＊ value and b from -2 to +22 ＊ the bright state reflectance spectrum and the reflectance spectra of the first, second reflectance color balance layer and the transmittance color balance layer are selected so as to have a value 21. A layered assembly according to claim 19 or 20.

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