wedge-shaped multilayer interlayer with an outer skin layer of varying thickness

Abstract

Multilayer interlayer films with enhanced optical and acoustic properties are provided, along with methods for making and using them. The interlayer films described herein may include at least two outer skin layers and an inner core layer, with one of the outer skin layers having a different thickness than the other at one or more locations along the interlayer. The multilayer interlayer films may also exhibit acoustic properties and, in some cases, may have an overall wedge-shaped thickness profile. Furthermore, in some embodiments, interlayer films and laminates formed therefrom may also reduce the transmission of infrared energy without sacrificing acoustic and / or optical performance.

Description

[Technical Field]

[0001]

[0001] The present invention relates to polymer interlayers and methods for manufacturing and using the same. Such interlayers can be used to form multilayer panels with desirable properties, such as windshields and windows. [Background technology]

[0002]

[0002] Poly(vinyl butyral) (PVB) is commonly used in the manufacture of polymer sheets that can be used as interlayers in light-transmitting laminates such as safety glass or polymer laminates. Safety glass often refers to a transparent laminate that includes a poly(vinyl butyral) sheet or interlayer placed between two sheets of glass. Safety glass is commonly used in automotive and building applications. Its main function is to absorb energy, such as energy caused by the impact of an object, without allowing it to penetrate through the opening or scattering glass fragments, thereby minimizing the extent of damage or injury to objects or people near the glass. Safety glass can also provide other beneficial effects, such as reducing ultraviolet (UV) and / or infrared (IR) light transmission and / or enhancing the appearance and aesthetic appeal of window openings.

[0003]

[0003] Safety glass interlayers have also been used as a key component in automotive head-up display (HUD) systems, for example, which can provide an image of the instrument cluster at the driver's eye level. Such displays allow the driver to concentrate on the approaching road while visually obtaining information from the dashboard. One type of interlayer used in such head-up display systems has a wedge-shaped vertical cross-section. The wedge shape of the interlayer is used to provide the precise optical dynamics required for the head-up display through the windshield. Unfortunately, like standard windshields, head-up display windshields can also result in undesirably high levels of noise transmission through the windshield.

[0004]

[0004] To address noise transmission, multilayer interlayers have been used that include at least one polymer layer having acoustic or sound-dampening properties. The acoustic layer may have different physical and / or chemical properties from the surrounding layers, which may result in less desirable optical properties such as cloudiness or mottling.

[0005]

[0005] Furthermore, some interlayers contain infrared-absorbing compounds to control the amount of energy that enters the vehicle's interior space through windows or windshields. An example of an infrared-absorbing compound is infrared-absorbing particles that can be dispersed throughout the interlayer. High concentrations of infrared-absorbing particles can block the transmission of infrared energy in a specific wavelength range, whether from external traffic sensors or on-board sensors such as rain sensors operating in the wavelength range of approximately 850 nm to 1050 nm. On the other hand, low concentrations of infrared-absorbing particles may not block a sufficient amount of irradiation, resulting in unwanted heat being generated in the vehicle's interior space due to infrared transmission.

[0006]

[0006] Therefore, there is a need for further improved compositions and methods for maintaining both the acoustic attenuation and visual properties of multilayer glass panels, in particular for multilayer glass panels that provide the performance of a head-up display using a wedge-shaped interlayer. It is advantageous that the interlayer has sufficient infrared absorption properties while maintaining the desired strength and acoustic attenuation properties. [Overview of the project]

[0007]

[0007] In one embodiment, the present invention relates to a wedge-shaped multilayer interfilm comprising a first wedge-shaped polymer layer, a second wedge-shaped polymer layer, and a third polymer layer between the first and second layers, wherein the first and second layers each have a Tg at least 10°C higher than the glass transition temperature (Tg) of the third layer, wherein at one or more locations of the interfilm the second layer is at least 10 percent thicker than the first layer, and at least one of the first and second layers has a thickness of 0.3 mm or less at one or more locations of the interfilm.

[0008]

[0008] In another embodiment, the present invention relates to a multilayer interfilm comprising first, second and third polymer layers, wherein the third layer is located between the first and second layers, and the first and second layers each have a Tg at least 10°C higher than the Tg of the third layer, wherein at one or more locations of the interfilm the first layer has a thickness of less than 0.3 mm and the second layer has a thickness of more than 0.3 mm, and satisfies at least one of the following criteria (i) to (iii): (i) at one or more locations of the interfilm the first layer has a thickness of at least 0.2 mm, (ii) at one or more locations of the interfilm the ratio of the thickness of the second layer to the thickness of the first layer is 2.5 or less:1, and (iii) the maximum difference in polyvinyl acetate content of any two of the first, second and third polymer layers is 13 weight percent or less.

[0009]

[0009] In another embodiment, the present invention relates to a wedge-shaped multilayer interfilm comprising a first wedge-shaped polymer outer layer, a second wedge-shaped polymer outer layer, and a polymer core layer sandwiched between the first and second outer layers, wherein each outer layer has a Tg at least 10°C higher than the Tg of the core layer, the interfilm has an overall wedge angle of at least 0.05 milliradians and 1 milliradian or less, the interfilm has a thinnest edge and a thickest edge, and the maximum thickness of at least one of the first and second outer layers does not exceed 0.3 mm within 40 centimeters from the thinnest edge.

[0010]

[0010] In another embodiment, the present invention relates to a wedge-shaped multilayer interfilm comprising first, second and third polymer layers, the third layer being located between the first and second layers, and the first and second layers each having a Tg at least 10°C higher than the Tg of the third layer, wherein the first layer has a thickness profile defined by the following formula: [0.0024(D e )+0.06] <T1<[1.975141-(1.6936517) / (1+(D e / 155.2664)^3.324064)] [In the formula, D e D is the distance from the thinnest edge of the interlayer in centimeters, and T1 is the distance in millimeters. e This relates to a wedge-shaped multilayer interlayer having the thickness of the first layer in [the given structure].

[0011]

[0011] In another embodiment, the present invention relates to a multilayer glazing comprising a first rigid substrate, a second rigid substrate, and an interlayer sandwiched between the first and second substrates, wherein the interlayer is an interlayer as described in any of the preceding paragraphs.

[0012] In another aspect, the present invention is a method of manufacturing a multilayer intermediate film, comprising: (a) preparing a skin resin; (b) preparing a core resin having a composition different from the skin resin; (c) forming a first skin layer from a portion of the skin resin and a second skin layer from another portion of the skin resin, wherein the resin used to form the first skin layer is supplied to the die at a mass flow rate different from the mass flow rate of the skin resin used to form the second skin polymer layer; (d) forming a core layer from at least a portion of the core resin; and (e) forming a multilayer polymer layer from the first skin layer, the second skin layer, and the core layer, wherein in one or more portions of the multilayer polymer layer, the first skin layer is at least 10 percent thicker than the second skin layer.

[0013] In another aspect, there is provided a tapered multilayer intermediate film comprising a first polymer layer having a wedge shape, a second polymer layer, and a third polymer layer between the first and second layers, wherein the first and second layers each have a glass transition temperature (Tg) at least 10 °C higher than the Tg of the third layer, and the intermediate film comprises a tapered zone having a thinnest edge and a thickest edge, and the thickness of the first polymer layer at the thinnest edge of the tapered zone is greater than the thickness of the first polymer layer at the thickest edge of the tapered zone.

[0014] In still another aspect, in one example generally illustrated in FIG. 13, there is provided a tapered multilayer intermediate film comprising first, second, and third polymer layers, wherein the third layer is located between the first and second layers, and at least one of the first and second layers is tapered. The intermediate film has a tapered zone having a thinnest edge and a thickest edge, and all points along a vertical centerline extending between the thinnest edge and the thickest edge satisfy the following relationship: 1.25Tca>TcL>0.75Tca [where TcL is the local combined thickness of the first and second layers, and Tca is the average combined thickness of the first and second layers calculated as follows: Tca=(Tc1+Tc2) / 2 In the formula, Tc1 is the combined thickness of the first and second layers at the thinnest edge, and Tc2 is the combined thickness of the first and second layers at the thickest edge. In some embodiments, as illustrated in Figure 13, for example, the thickness of the first layer at the thinnest edge (indicated as T1s1) and the thickness of the second layer at the thinnest edge (indicated as T2s1) can be added together to obtain Tc1, while the thickness of the first layer at the thickest edge (indicated as T1s2) and the thickness of the second layer at the thickest edge (indicated as T2s2) can be added together to obtain Tc2.

[0015]

[0015] In a further embodiment, a wedge-shaped multilayer interfilm is provided which includes first, second, and third polymer layers, the third layer being located between the first and second layers, and at least one of the first and second layers being wedge-shaped. The interfilm includes a tapered region having a thinnest edge and a thickest edge, the first layer having a thickness that increases from the thinnest to the thickest edge of the tapered region, the second layer having a thickness that decreases from the thinnest to the thickest edge of the tapered region, and at least one of the first, second, and third layers containing at least one IR absorber.

[0016]

[0016] In a further embodiment, a wedge-shaped multilayer interfilm is provided, comprising first, second, and third polymer layers, wherein the third layer is located between the first and second layers, and at least one of the first and second layers is wedge-shaped. The interfilm has a thinnest edge and a thickest edge, as well as a tapered region having an overall wedge angle of at least 0.30 mrad, wherein the total solar transmittance (%Tts) measured at the thickest edge of the tapered region is within about 5% of the total solar transmittance measured at the thinnest edge of the tapered region. At least one of the first, second, and third polymer layers contains an IR absorber, and the layer containing the IR absorber is formed from the same polymer material at both the thinnest and thickest edges of the tapered region, respectively. [Brief explanation of the drawing]

[0017]

[0017] Various embodiments of the technology of the present invention are described in detail below with reference to the accompanying drawings. [Figure 1a]

[0018] This is a vertical cross-section of a wedge-shaped interlayer according to an embodiment of the present invention, specifically illustrating certain dimensions of the interlayer. [Figure 1b]

[0019] This is a vertical cross-section of a wedge-shaped interlayer according to an embodiment of the present invention, specifically illustrating the measured value of the wedge angle. [Figure 1c]

[0020] This is a vertical cross-section of a wedge-shaped interlayer according to an embodiment of the present invention, specifically illustrating an interlayer having tapered regions positioned between multiple planar regions. [Figure 2]

[0021] This is a vertical cross-section of a wedge-shaped interlayer according to an embodiment of the present invention, specifically illustrating an interlayer having three or more polymer layers. [Figure 3]

[0022] This is a vertical cross-section of a wedge-shaped interlayer according to an embodiment of the present invention, specifically illustrating an example of an interlayer having skin layers of different thicknesses. [Figure 4]

[0023] This is a vertical cross-section of a wedge-shaped interlayer according to an embodiment of the technology of the present invention, specifically illustrating another example of an interlayer having skin layers of different thicknesses. [Figure 5]

[0024] This is a vertical cross-section of an interlayer according to an embodiment of the present invention, specifically illustrating an example of an interlayer having skin layers of different thicknesses. [Figure 6]

[0025] This is a schematic diagram of an interlayer according to an embodiment of the present invention, specifically illustrating a particular dimension of the interlayer. [Figure 7]

[0026] Figure 6 is a schematic diagram of a laminated windshield according to an embodiment of the present invention that utilizes the interlayer film illustrated in the example. [Figure 8]

[0027] This graph illustrates the thicknesses of the first, second, and third polymer layers in the interlayer according to an embodiment of the present invention, as well as the overall thickness of the interlayer, as shown as a function of position. [Figure 9]

[0028] This graph illustrates the thickness range of the first layer of the interlayer according to an embodiment of the present invention, shown as a function of position. [Figure 10]

[0029] This is a cross-section of the thickness of the comparative interlayer being tested as described in Example 1. [Figure 11]

[0030] This is a cross-section of the thickness of the interlayer according to an embodiment of the technology of the present invention, tested as described in Example 1. [Figure 12a]

[0031] This is a vertical cross-section of a wedge-shaped interlayer according to an embodiment of the present invention, specifically illustrating an example of an interlayer having a skin layer with an inverted wedge structure. [Figure 12b]

[0032] This is a vertical cross-section of a wedge-shaped interlayer according to an embodiment of the art of the present invention, specifically illustrating another example of an interlayer having a skin layer having an inverted wedge structure. [Figure 12c]

[0033] This is a vertical cross-section of a wedge-shaped interlayer according to an embodiment of the present invention, specifically illustrating yet another example of an interlayer having a skin layer with an inverted wedge structure. [Figure 12d]

[0034] This is a vertical cross-section of a wedge-shaped interlayer according to an embodiment of the present invention, specifically illustrating yet another example of an interlayer having a skin layer with an inverted wedge structure. [Figure 12e]

[0035] This is a vertical cross-section of a wedge-shaped interlayer according to an embodiment of the technology of the present invention, specifically illustrating a further example of an interlayer having a skin layer with an inverted wedge structure. [Figure 12f]

[0036] This is a vertical cross-section of a molded interfilm according to an embodiment of the present invention, specifically illustrating yet another example of an interfilm having a skin layer with an inverted wedge structure. [Figure 12g]

[0037] This is a vertical cross-section of a wedge-shaped interlayer according to an embodiment of the present invention, specifically illustrating yet another example of an interlayer having a skin layer with an inverted wedge structure. [Figure 13]

[0038] This is a vertical cross-section of a wedge-shaped interlayer according to an embodiment of the present invention, specifically illustrating the combined skin thickness along the vertical dimension of the interlayer. [Modes for carrying out the invention]

[0018]

[0039] Polymer interlayers suitable for forming laminates, such as windshields and other glass laminates, along with methods for producing and using such interlayers, are described herein. The interlayers described herein may include acoustic interlayers having sound-dampening properties. In addition, in some cases the interlayers may be wedge-shaped or tapered, while in other cases they may be flat. Furthermore, the intermediates described herein may also exhibit enhanced optical properties such as mottling, making them particularly suitable for automotive applications.

[0019]

[0040] As used herein, the terms “polymer resin composition” and “resin composition” refer to a composition comprising one or more polymer resins. The polymer composition may optionally contain other components, e.g., plasticizers and / or other additives. As used herein, the terms “polymer polymer layer” and “polymer layer” refer to one or more polymer resins formed on a polymer sheet, optionally combined with one or more plasticizers. Here again, the polymer layer may, but is not required, contain additional additives. As used herein, the term “interlayer” refers to a single or multilayer polymer sheet suitable for use with at least one rigid substrate to form a multilayer panel. The terms “single-sheet” interlayer and “integrated” interlayer refer to an interlayer formed from a single resin sheet, while the terms “multilayer” and “multilayer” intermediate refer to an intermediate having two or more resin sheets that are co-extruded, laminated, or otherwise bonded to one another.

[0020]

[0041] Figures 1-5 illustrate several embodiments of the interlayer 10. As illustrated in Figures 1-5, the interlayer 10 described herein may include, for example, a multilayer interlayer having a first polymer layer 1, a second polymer layer 2, and a third polymer layer 3. When used herein, the terms “first,” “second,” “third,” etc., are used to describe various elements, but such elements should not be unnecessarily limited by these terms. These terms are used simply to distinguish one element from another and do not necessarily imply a particular order or even specific elements. For example, an element may be considered a “first” element in this description and, without contradiction, a “second” element in the claims. Consistency is maintained within the description and in each independent claim, but such nomenclature is not necessarily intended to be consistent between them. Figure 2 illustrates one embodiment of an interlayer including a fourth layer 4 and a fifth layer 5 positioned between the first layer 1 and the third layer 3, and between the third layer 3 and the second layer 2, respectively.

[0021]

[0042] In some embodiments, the interlayer 10 may have an overall wedge-shaped or wedge-formed profile. As used herein, the terms “wedge-shaped” or “wedge-formed” mean that at least a portion of it has a cross-sectional geometry that increases from a relatively thin dimension to a relatively thick dimension. As shown in Figure 1, when wedge-formed, the interlayer may include a tapering region 16 having a thinnest edge 14 and a thickest edge 12 located on the opposite side, and may exhibit a non-uniform thickness profile between the thinnest and thickest edges 14, 12. In some embodiments, the wedge-formed interlayer or layer may have a minimum wedge angle of at least 0.05 mrad.

[0022]

[0043] In some embodiments, the thickest edge 12 of the tapered region 16 may have a total thickness (of all layers at that point) of at least about 0.60 mm, at least about 0.65 mm, at least about 0.70 mm, at least about 0.75 mm, at least about 0.80 mm, at least about 0.85 mm, or at least about 0.90 mm, and / or about 2.0 mm or less, about 1.95 mm or less, about 1.90 mm or less, about 1.85 mm or less, about 1.80 mm or less, about 1.75 mm or less, about 1.70 mm or less, about 1.65 mm or less, about 1.60 mm or less, about 1.55 mm or less, or about 1.50 mm or less.

[0023]

[0044] The thinnest edge portion 14 of the tapered region 16 may have a total thickness (of all layers at that point) of at least about 0.50 mm, at least about 0.55 mm, at least about 0.60 mm, at least about 0.65 mm, or at least about 0.70 mm, and / or about 1.1 mm or less, about 1.0 mm or less, about 0.95 mm or less, about 0.90 mm or less, about 0.85 mm or less, about 0.80 mm or less, about 0.75 mm or less, or about 0.70 mm or less.

[0024]

[0045] In some embodiments, at least about 10 percent, at least about 20 percent, at least about 30 percent, at least about 40 percent, at least about 50 percent, at least about 60 percent, at least about 70 percent, at least about 80 percent, or at least about 90 percent of the entire vertical cross-section of the interlayer 10 may be wedge-formed or have a non-uniform thickness. As used herein, the term “vertical cross-section” refers to a cross-section taken between the thickest and thinnest edges 12, 14 of the wedge-formed interlayer 10 (or tapered region 16). Figures 1-4 depict various embodiments of the wedge-formed interlayer 10 taken along each vertical cross-section. Additionally or alternatively, about 90 percent or less, about 80 percent or less, about 70 percent or less, about 60 percent or less, about 50 percent or less, about 40 percent or less, about 30 percent or less, or about 20 percent or less of the entire vertical cross-section of the intermediate 10 may have a non-uniform thickness. In other cases, the entire vertical cross-section (100 percent) may be wedge-formed. For example, all vertical sections of the intermediate bodies depicted in Figures 1-4 have all vertical sections with non-uniform thickness.

[0025]

[0046] In some embodiments, at least one edge of the tapered region 16 may be located at or near at least one edge of the interlayer itself (shown as the thickest edge 12 and the thinnest edge 14 in Figure 1), while in other embodiments, the edge of the tapered region 16 may be separated from at least one edge of the interlayer 10. In some cases, the ratio of the length of the tapered region 16 to the length of the interlayer 10 (measured between the thinnest edge 14 and the thickest edge 12 of the interlayer 10) may be at least about 0.10:1, at least about 0.15:1, at least about 0.20:1, at least about 0.25:1, at least about 0.30:1, at least about 0.35:1, at least about 0.40:1, at least about 0.45:1, at least about 0.50:1, at least about 0.55:1, at least about 0.60:1, at least about 0.65:1, at least about 0.70:1, at least about 0.75:1, at least about 0.80:1, at least about 0.85:1, at least about 0.90:1, at least about 0.95:1, or at least about 0.99:1.

[0026]

[0047] Alternatively or additionally, the ratio of the length of the tapered region 16 to the length of the interlayer 10 may be approximately 0.99:1, approximately 0.95:1, approximately 0.90:1, approximately 0.85:1, approximately 0.80:1, approximately 0.75:1, approximately 0.70:1, approximately 0.65:1, approximately 0.60:1, approximately 0.55:1, approximately 0.50:1, approximately 0.45:1, approximately 0.40:1, approximately 0.35:1, approximately 0.30:1, approximately 0.25:1, approximately 0.20:1, approximately 0.15:1, or approximately 0.10:1.

[0027]

[0048] In some embodiments, the tapered region 16 constitutes at least about 10 percent, at least about 15 percent, at least about 20 percent, at least about 25 percent, at least about 30 percent, at least about 35 percent, at least about 40 percent, at least about 45 percent, or at least about 50 percent and / or about 99 percent or less, about 95 percent or less, about 90 percent or less, about 85 percent or less, about 80 percent or less, about 75 percent or less, about 70 percent or less, about 65 percent or less, about 60 percent or less, about 55 percent or less, or about 50 percent or less of the total width (in the vertical direction as shown in Figure 6). An example of an interlayer having a tapered region 16 smaller than the total width of the interlayer 10 is shown in Figure 1c.

[0028]

[0049] In some embodiments, the distance between the thinnest edge 14 and the thickest edge 12 of the interlayer 10 (or tapered region 16) is at least about 50 cm, at least about 55 cm, at least about 60 cm, at least about 65 cm, at least about 70 cm, at least about 75 cm, at least about 80 cm, at least about 85 cm, at least about 90 cm, at least about 95 cm, at least about 100 cm, at least about 110 cm, at least about 120 cm, at least about 130 cm, and at least about 14 0 cm, at least about 150 cm, at least about 160 cm, at least about 170 cm, at least about 180 cm, at least about 190 cm, or at least about 200 cm, and / or about 750 cm or less, about 700 cm or less, about 650 cm or less, about 600 cm or less, about 550 cm or less, about 500 cm or less, about 450 cm or less, about 400 cm or less, about 350 cm or less, about 300 cm or less, about 250 cm or less, about 200 cm or less, or about 150 cm or less.

[0029]

[0050] In some embodiments, the length of the tapered region 16 (measured perpendicular to the width of the interlayer shown in Figure 6) is at least about 35 cm, at least about 40 cm, at least about 45 cm, at least about 50 cm, at least about 55 cm, at least about 60 cm, at least about 65 cm, at least about 70 cm, at least about 75 cm, at least about 80 cm, at least about 85 cm, at least about 90 cm, at least about 95 cm, or at least about 100 cm, and / or about 200 cm or less, about 190 cm or less, about 180 cm or less, about 170 cm or less, about 160 cm or less, about 150 cm or less, about 140 cm or less, about 130 cm or less, about 120 cm or less, about 110 cm or less, or about 100 cm or less.

[0030]

[0051] In some embodiments, if the tapered region 16 does not extend across the entire width of the interlayer 10, the distance between the boundaries of the tapered region 16 may be at least about 5 cm, at least about 10 cm, at least about 15 cm, at least about 20 cm, at least about 25 cm, at least about 30 cm, at least about 35 cm, at least about 40 cm, or at least about 45 cm, and / or about 200 cm or less, about 175 cm or less, about 150 cm or less, about 100 cm or less, or about 75 cm or less. The width of the tapered region 16 (measured between the thinnest edge 14 and the thickest edge 12 of the tapered region 16 in a direction parallel to the width of the interlayer 10 shown in Figure 6) may be at least about 60 mm, at least about 65 mm, at least about 70 mm, at least about 75 mm, at least about 80 mm, at least about 85 mm, at least about 90 mm, at least about 95 mm, or at least about 100 mm, and / or about 150 mm or less, about 140 mm or less, about 130 mm or less, about 120 mm or less, about 110 mm or less, about 100 mm or less, about 90 mm or less, about 80 mm or less, or about 70 mm or less. The tapered region 16 (or interlayer 10) may have a minimum thickness (T) measured at the thinner end of the tapered region 16 (or interlayer 10). zmin ), and the maximum thickness (T) measured at the thicker end of the tapered region 16 (or interlayer 10). zmax ) may include. In some embodiments, Tzmin may be at least about 0.25 mm, at least about 0.30 mm, at least about 0.35 mm, at least about 0.38 mm, at least about 0.40 mm, at least about 0.45 mm, at least about 0.50 mm, at least about 0.55 mm, at least about 0.60 mm, and / or about 2.5 mm or less, about 2.4 mm or less, about 2.3 mm or less, about 2.2 mm or less, about 2.1 mm or less, about 2.0 mm or less, about 1.9 mm or less, about 1.8 mm or less, about 1.7 mm or less, about 1.6 mm or less, about 1.5 mm or less, about 1.4 mm or less, about 1.3 mm or less, about 1.2 mm or less, about 1.1 mm or less, about 1.0 mm or less, about 0.9 mm or less, about 0.85 mm or less, or about 0.80 mm or less.

[0031]

[0052] T zmax is T zmin may be at least 0.13 mm, at least about 0.15 mm, at least about 0.20 mm, at least about 0.25 mm, at least about 0.30 mm, at least about 0.35 mm, at least about 0.40 mm, at least about 0.45 mm, at least about 0.50 mm, at least about 0.55 mm, at least about 0.60 mm, at least about 0.65 mm, at least about 0.70 mm, at least about 0.75 mm, at least about 0.80 mm, at least about 0.85 mm, at least about 0.90 mm, at least about 0.95 mm, or at least about 1.0 mm thicker than T. Alternatively, or further, T zmax is T zmin may be about 2.0 mm or less, about 1.9 mm or less, about 1.8 mm or less, about 1.7 mm or less, about 1.6 mm or less, about 1.5 mm or less, about 1.4 mm or less, about 1.3 mm or less, about 1.2 mm or less, about 1.1 mm or less, or about 1.0 mm or less thicker than T.

[0032]

[0053] T zmaxIt may be at least about 0.35 mm, at least about 0.38 mm, at least about 0.40 mm, at least about 0.45 mm, at least about 0.50 mm, at least about 0.53 mm, at least about 0.55 mm, at least about 0.60 mm, at least about 0.65 mm, at least about 0.70 mm, at least about 0.75 mm, or at least about 0.76 mm, and / or 2.5 mm or less, about 2.4 mm or less, about 2.3 mm or less, about 2.2 mm or less, about 2.1 mm or less, about 2 mm or less, about 1.9 mm or less, about 1.8 mm or less, about 1.7 mm or less, about 1.6 mm or less, or about 1.5 mm or less.

[0033]

[0054] If the interlayer 10 is a wedge-shaped interlayer, the tapered region 16 may include at least one wedge angle (Θ), which is defined as the angle formed between a first reference line extending through two points in the interlayer where the boundaries of the first and second tapered regions intersect with the first (upper) surface of the interlayer, and a second reference line extending through two points where the boundaries of the first and second tapered regions intersect with the second (lower) surface of the interlayer, as is generally shown in Figure 1b. In certain embodiments, the tapered region 16 may have a wedge angle of at least about 0.05 milliradians (mrad), at least about 0.10 mrad, at least about 0.13 mrad, at least about 0.15 mrad, at least about 0.20 mrad, at least about 0.25 mrad, at least about 0.30 mrad, at least about 0.35 mrad, or at least about 0.40 mrad, and / or about 1.0 mrad or less, about 0.90 mrad or less, about 0.85 mrad or less, about 0.80 mrad or less, about 0.75 mrad or less, about 0.70 mrad or less, about 0.65 mrad or less, or about 0.60 mrad or less.

[0034]

[0055] In some embodiments, the interlayer 10 has an overall wedge angle of at least about 0.3mrad, at least about 0.35mrad, at least about 0.40mrad, at least about 0.45mrad, at least about 0.50mrad, at least about 0.55mrad, at least about 0.60mrad, at least about 0.65mrad, at least about 0.70mrad, at least about 0.75mrad, and / or about 0.80mrad or less, about 0.75mrad or less, about 0.70mrad or less, about 0.65mrad or less, about 0.60mrad or less, about 0.55mrad or less, about 0.50mrad or less, about 0.45mrad or less, about 0.40mrad or less, about 0.35mrad or less, and about 0.30mrad or less.

[0035]

[0056] In some embodiments, the wedge angle of the interlayer 10 may be a constant wedge angle that does not change from end to end of the tapered region, while in other embodiments, the tapered region may include at least two constant-angle regions having different wedge angles. In such cases, the tapered region may have a linear thickness profile. In some embodiments, the wedge angle may vary continuously over all or part of the tapered region, thereby providing a variable-angle region having a curved thickness profile. Specific embodiments of interlayers having different tapered region configurations are described in detail in U.S. Patent Application Publication No. 2017 / 0285339, which in whole is incorporated herein by reference to the extent not inconsistent with this disclosure.

[0036]

[0057] In some embodiments, at least one layer or at least a portion of the interlayer 10 may be flat, for example, such that the vertical cross-section of the layer or interlayer has a uniform thickness of at least about 90, at least about 92, at least about 95, at least about 97, at least about 99, or all of them. That is, the interlayer 10 may have a cross-sectional shape that remains the same thickness. An example of a flat interlayer is shown in Figure 5, and another is shown in Figure 12f. The wedge angle of an interlayer with a flat or constant thickness profile is approximately zero or less than 0.05 mrad.

[0037]

[0058] In some embodiments, the interlayer 10 may include at least one flat region 18. As generally shown in Figure 1c, the flat region 18b of the interlayer 10 may be located adjacent to the thickest edge 12 of the tapered region 16 and may have an average thickness of, for example, within about 20 percent, 15 percent, 10 percent, 5 percent, 2 percent, or 1 percent of the thickness of the thickest edge 12 of the tapered region 16. Additionally or alternatively, the interlayer may have a flat region 18a located adjacent to the thinnest edge 14 of the tapered region 16, which may have an average thickness of within about 20 percent, 15 percent, 10 percent, 5 percent, 2 percent, or 1 percent of the thickness of the thinnest edge 14 of the tapered region 16. In some embodiments, the flat regions (or regions 18a, b) of the interlayer may constitute at least about 5 percent, at least about 10 percent, at least about 15 percent, at least about 20 percent, at least about 25 percent, at least about 30 percent, at least about 35 percent, or at least about 40 percent and / or about 85 percent or less, about 80 percent or less, about 75 percent or less, about 70 percent or less, about 65 percent or less, about 60 percent or less, about 55 percent or less, or about 50 percent or less. Although shown in Figure 1c as including both a thin flat region 18a and a thick flat region 18b, it should be understood that the interlayer according to embodiments of the present invention may include one or the other or both of the thin flat region 18a and the thick flat region 18b.

[0038]

[0059] As shown in the embodiments of the multilayer interlayer shown in Figures 1-5, the third polymer layer 3 can be placed between the first polymer layer 1 and the second polymer layer 2. The third layer may be called the “core” layer or “inner” layer, and the outer polymer layers 1 and 2 may be called the “skin” layer or “outer” layer. If the interlayer contains three or more layers, the outermost layers, such as the first and second layers shown in Figure 2, may be called skin layers, while the innermost layers, such as the third layer shown in Figure 2, may be called core layers.

[0039]

[0060] In some embodiments, one or more skin layers or core layers may be wedge-shaped. In some cases, only the outer skin layer may be wedge-shaped, and the inner core layer may be flat or substantially flat. In other cases, one of the skin layers may be wedge-shaped and the other flat. In some cases, both the outermost skin layer and the innermost core layer may be wedge-shaped. In other cases, the outer layer may be flat and the inner core layer may be wedge-shaped. In yet another case, the outer skin layer may be wedge-shaped and the inner core layer may be wedge-shaped or flat.

[0040]

[0061] If one or more layers of the interlayer 10 are wedge-shaped, the layers may have a wedge angle of at least about 0.05 milliradians, at least about 0.10 milliradians, at least about 0.15 milliradians, at least about 0.20 milliradians, at least about 0.25 milliradians, at least about 0.30 milliradians, or at least about 0.35 milliradians, and / or less than or equal to about 1 milliradian, less than or equal to about 0.95 milliradians, less than or equal to about 0.90 milliradians, less than or equal to about 0.85 milliradians, less than or equal to about 0.80 milliradians, less than or equal to about 0.75 milliradians, less than or equal to about 0.70 milliradians, less than or equal to about 0.65 milliradians, less than or equal to about 0.60 milliradians, or less than or equal to about 0.55 milliradians. If two or more layers are wedge-shaped, the layers may have substantially similar wedge angles of about 0.001 milliradians, about 0.005 milliradians, or about 0.01 milliradians relative to each other. In some embodiments, the wedge angles of the two layers may be about 15 percent, about 10 percent, about 5 percent, about 3 percent, about 2 percent, or about 1 percent relative to each other.

[0041]

[0062] Alternatively, one or more wedge-shaped layers may have a different wedge angle than one or more other layers. For example, in some embodiments, if both the innermost core layer and at least one outer skin layer are wedge-shaped, the core layer may have a wedge angle greater or smaller than the wedge angle of the core layer (or more layers). In some embodiments, the difference in wedge angles between two or more wedge-shaped layers may be at least about 0.05 milliradians, at least about 0.075 milliradians, at least about 0.10 milliradians, or at least about 0.12 milliradians. In some embodiments, the wedge angles of two layers may be greater than 15 percent from each other and at least about 20 percent, at least about 25 percent, at least about 30 percent, at least about 35 percent, or at least about 40 percent.

[0042]

[0063] Overall, each layer of the multilayer interlayer 10 may have a thickness of at least about 0.05 mm, at least about 0.10 mm, at least about 0.15 mm, at least about 0.20 mm, at least about 0.25 mm, at least about 0.30 mm, at least about 0.35 mm, or at least about 0.40 mm, and / or about 0.60 mm or less, about 0.55 mm or less, about 0.50 mm or less, about 0.45 mm or less, about 0.40 mm or less, about 0.35 mm or less, or less than about 0.30 mm.

[0043]

[0064] In some embodiments, if the interlayer 10 includes two or more wedge-shaped interlayers, the wedge-shaped layers may have a thick end and a thin end opposite the thick end. In some embodiments, the thick end of one or more wedge-shaped layers may be at least about 127 μm (5 mil), at least about 152.4 μm (6 mil), at least about 177.8 μm (7 mil), at least about 203.2 μm (8 mil), at least about 228.6 μm (9 mil), at least about 254 μm (10 mil), at least about 279.4 μm (11 mil), or at least about 304.8 μm (12 mil). , at least about 330.2 μm (13 mils), at least about 355.6 μm (14 mils), at least about 381 μm (15 mils), at least about 406.4 μm (16 mils), at least about 431.8 μm (17 mils), at least about 457.2 μm (18 mils), at least about 482.6 μm (19 mils), at least about 508 μm (20 mils), and / or less than or equal to about 1270 μm (50 mils) , approximately 1193.8 μm (47 mils) or less, approximately 1143 μm (45 mils) or less, approximately 1066.8 μm (42 mils) or less, approximately 1016 μm (40 mils) or less, approximately 939.8 μm (37 mils) or less, approximately 889 μm (35 mils) or less, approximately 863.6 μm (34 mils) or less, approximately 838.2 μm (33 mils) or less, approximately 812.8 μm (32 mils) or less, approximately 787.4 μm (31 mils) or less, approximately 762 μm (30 mils) ) may have a thickness of approximately 736.6 μm (29 mils) or less, approximately 711.2 μm (28 mils) or less, approximately 685.8 μm (27 mils) or less, approximately 660.4 μm (26 mils) or less, approximately 635 μm (25 mils) or less, approximately 609.6 μm (24 mils) or less, approximately 584.2 μm (23 mils) or less, approximately 558.8 μm (22 mils) or less, approximately 533.4 μm (21 mils) or less, or approximately 508 μm (20 mils) or less.

[0044]

[0065] Additionally or alternatively, the thin edges of one or more wedge layers may be at least about 127 μm (5 mil), at least about 152.4 μm (6 mil), at least about 177.8 μm (7 mil), at least about 203.2 μm (8 mil), at least about 228.6 μm (9 mil), at least about 254 μm (10 mil), at least about 279.4 μm (11 mil), at least about 304.8 μm (12 mil), at least about 330.2 μm (13 mil), at least about 355.6 μm (14 mil), at least about 381 μm (15 mil), at least about 406.4 μm (16 mil), at least about 431.8 μm (17 mil), at least about 457.2 μm (18 mil, at least about 482.6 μm (19 mil), at least about 508 μm (20 mil), and / or less than or equal to about 889 μm (35 mil), less than or equal to about 863.6 μm (34 mil), less than or equal to about 838.2 μm (33 mil), less than or equal to about 812.8 μm (32 mil), less than or equal to about 787.4 μm (31 mil), less than or equal to about 762 μm (30 mil), less than or equal to about 736.6 μm (29 mil), less than or equal to about 711 It may have a thickness of 0.2 μm (28 mils) or less, approximately 685.8 μm (27 mils) or less, approximately 660.4 μm (26 mils) or less, approximately 635 μm (25 mils) or less, approximately 609.6 μm (24 mils) or less, approximately 584.2 μm (23 mils) or less, approximately 558.8 μm (22 mils) or less, approximately 533.4 μm (21 mils) or less, or approximately 508 μm (20 mils) or less.

[0045]

[0066] In some embodiments, one or more layers may have a different thickness from one or more other layers. For example, at least one of the outer skin layers may be thicker than the inner core layer, as shown in Figures 1-5. If there are layers in addition to the skin and core layers, the additional layers may be thinner than the skin and core layers, as shown in Figure 2. In some cases, no two layers may have the same thickness, as shown in Figures 1-5, while in other embodiments, at least two layers may have similar thicknesses. As used herein, “similar thickness” means having a thickness (average or nominal) of no more than 0.02 mm of another layer. As used herein, “different thickness” means having a thickness (average, nominal, or at some point) that is more than 0.02 mm thicker or thinner than another layer.

[0046]

[0067] In some embodiments, the outer skin layers (shown as layers 1 and 2 in Figures 1-5) may have similar thicknesses, for example, such that the maximum difference between the thicknesses of the two outer layers is about 5 percent or less, about 3 percent or less, about 2 percent or less, about 1 percent or less, or about 0.5 percent or less. In some cases, the two outer skin layers may have the same nominal thickness.

[0047]

[0068] In other embodiments, at least a portion of one outer skin layer 1 or 2 may be thicker than at least a portion of the other outer skin layer 2 or 1. For example, in some embodiments, one of the outer skin layers 1 or 2 may be at least about 5 percent, at least about 10 percent, at least about 15 percent, at least about 20 percent, at least about 25 percent, at least about 30 percent, at least about 35 percent, at least about 40 percent, at least about 45 percent, or at least about 50 percent thicker than the other outer skin layer at one or more locations on the interlayer. Alternatively, at least a portion of one outer skin layer 1 or 2 may be at least about 90 percent, at least about 85 percent, at least about 80 percent, at least about 75 percent, at least about 70 percent, at least about 65 percent, at least about 60 percent, at least about 55 percent, at least about 50 percent, or at least about 45 percent thicker than the other outer skin layer 1 or 2 at one or more locations along the interlayer.

[0048]

[0069] In some embodiments, at one or more locations on the interlayer 10, one of the outer skin layers 1 or 2 may have a thickness of less than 0.30 mm, about 0.29 mm or less, about 0.28 mm or less, about 0.27 mm or less, about 0.26 mm or less, about 0.25 mm or less, about 0.24 mm or less, about 0.23 mm or less, about 0.22 mm or less, about 0.21 mm or less, about 0.20 mm or less, about 0.19 mm or less, about 0.18 mm or less, about 0.17 mm or less, or about 0.16 mm or less. Additionally or alternatively, at one or more locations on the interlayer, one of the outer skin layers 1 or 2 may have a thickness of at least about 0.20 mm, at least about 0.22 mm, at least about 0.24 mm, at least about 0.26 mm, at least about 0.28 mm, or at least about 0.29 mm. In some cases, at one or more locations on the interlayer, at least one of the outer skin layers 1 or 2 may have a thickness in the range of about 0.20 to 0.30 mm, at least about 0.22 to about 0.30 mm, or about 0.24 to about 0.29 mm.

[0049]

[0070] In some embodiments, if one of the outer skin layers 1 or 2 has a thickness of less than 0.30 mm, the other outer skin layer 2 or 1 may have a thickness of more than 0.3 mm, or at least about 0.31 mm, at least about 0.32 mm, at least about 0.33 mm, at least about 0.34 mm, at least about 0.35 mm, or at least about 0.36 mm at one or more locations on the interlayer.

[0050]

[0071] In some embodiments, over at least about 10 percent, at least about 20 percent, at least about 40 percent, at least about 60 percent, at least about 80 percent, or 100 percent of the total area of ​​the interlayer, one of the outer skin layers 1 or 2 may have a thickness of less than about 0.30 mm, less than about 0.29 mm, less than about 0.28 mm, less than about 0.27 mm, less than about 0.26 mm, or less than about 0.25 mm, while the other outer skin layer 2 or 1 may have a thickness greater than about 0.30 mm, at least about 0.31 mm, at least about 0.32 mm, at least about 0.34 mm, or at least about 0.35 mm.

[0051]

[0072] According to some embodiments, one of the outer skin layers 1 or 2 of the interlayer may be at least about 0.01 mm, at least about 0.025 mm, at least about 0.05 mm, at least about 0.075 mm, at least about 0.10 mm, at least about 0.12 mm, at least about 0.15 mm, at least about 0.17 mm, at least about 0.20 mm, at least about 0.22 mm, at least about 0.25 mm, or at least about 0.27 mm thicker (or thinner) than the other skin layer 2 or 1. Additionally or alternatively, one of the outer skin layers 1 or 2 may be about 0.40 mm thicker (or thinner) than the other outer skin layer 2 or 1 by about 0.39 mm, about 0.38 mm, about 0.37 mm, about 0.36 mm, about 0.35 mm, about 0.34 mm, about 0.33 mm, about 0.32 mm, about 0.31 mm, about 0.30 mm, or about 0.29 mm.

[0052]

[0073] In some embodiments, at one or more locations on the interlayer, the ratio of the thickness of one of the outer skin layers 1 or 2 to the thickness of the other outer skin layer 2 or 1 may be 2.5:1, about 2.2:1, about 2.0:1, about 1.8:1, about 1.6:1, or about 1.5:1. The above difference in thickness between the two outer skin layers 1 or 2 may be a difference in average thickness across the vertical cross-section of the interlayer, or a difference in nominal thickness of the layers. In other embodiments, particularly when the interlayer is a wedge-shaped interlayer, the above difference may refer to a difference in maximum thickness, or a difference in thickness at a specific distance from one of the edges of the interlayer.

[0053]

[0074] In some embodiments, the combined thickness of the two outermost skin layers 1 or 2 is at one or more locations within the interlayer 10 or tapered region 16, or on average, at least about 508 μm (20 mils), at least about 558.8 μm (22 mils), at least about 635 μm (25 mils), at least about 685.8 μm (27 mils), at least about 711.2 μm (28 mils), at least about 762 μm (30 mils), at least about 812.8 μm (32 mils), at least about 889 μm (35 mils), at least about 939.8 μm (37 mils), and at least about 1 It may be 0.16 μm (40 mil), at least about 1066.8 μm (42 mil), or at least about 1143 μm (45 mil), and / or about 1397 μm (55 mil) or less, about 1346.2 μm (53 mil) or less, about 1270 μm (50 mil) or less, about 1193.8 μm (47 mil) or less, about 1143 μm (45 mil) or less, about 1066.8 μm (42 mil) or less, about 1016 μm (40 mil) or less, about 939.8 μm (37 mil) or less, about 889 μm (35 mil) or less, about 812.8 μm (32 mil) or less, or about 762 μm (30 mil) or less.

[0054]

[0075] If at least one of skin layers 1 or 2 is a wedge-shaped layer, the combined skin thickness at the thinnest edge of the tapered region 16 (or interlayer 10) may be at least about 508 μm (20 mils), at least about 558.8 μm (22 mils), at least about 635 μm (25 mils), at least about 685.8 μm (27 mils), at least about 711.2 μm (28 mils), and / or about 1016 μm (40 mils) or less, about 939.8 μm (37 mils) or less, about 889 μm (35 mils) or less, about 812.8 μm (32 mils) or less, or about 762 μm (30 mils) or less. Alternatively, the combined thickness of the two outermost skin layers 1 or 2 at the thickest edge of the tapered region 16 (or interlayer 10) may be at least about 762 μm (30 mils), at least about 812.8 μm (32 mils), at least about 889 μm (35 mils), at least about 939.8 μm (37 mils), at least about 1016 μm (40 mils), at least about 1066.8 μm (42 mils), at least about 1143 μm (45 mils), and / or less about 1397 μm (55 mils), less than or equal to 1346.2 μm (53 mils), less than or equal to 1270 μm (50 mils), less than or equal to 1193.8 μm (47 mils), less than or equal to 1143 μm (45 mils), less than or equal to 1066.8 μm (42 mils).

[0055]

[0076] If the interlayer 10 is wedge-shaped overall, the ratio of the combined thickness of skin layer 1 or 2 at the thickest edge 12 of the tapered region 16 (or interlayer 10) to the combined thickness of skin layer 1 or 2 at the thinnest edge 14 of the tapered region 16 (or interlayer 10) may be at least about 1.1:1, at least about 1.2:1, at least about 1.25:1, at least about 1.3:1, at least about 1.35:1, at least about 1.4:1, at least about 1.45:1, at least about 1.5:1, and / or about 1.8 or less:1, about 1.75 or less:1, about 1.7 or less:1, about 1.65 or less:1, about 1.6 or less:1, about 1.55 or less:1, about 1.5 or less:1, about 1.45 or less:1, and about 1.4 or less:1.

[0056]

[0077] In some embodiments, the ratio of the innermost core layer 3 to the combined thickness of the two outermost skin layers 1 or 2 at the thinnest edge 14 of the tapered region 16 (or interlayer 10) may be at least about 0.05:1, at least about 0.075:1, at least about 0.10:1, at least about 0.125:1, and / or about 0.25 or less:1, about 0.22 or less:1, about 0.20 or less:1, or about 0.175 or less:1. In some embodiments, the ratio of the thickness of the innermost core layer 3 to the combined thickness of the two outer skin layers 1 or 2 at the thickest edge 12 of the tapered region 16 (or interlayer 10) may be at least about 0.05:1, at least about 0.075:1, at least about 0.10:1, at least about 0.125:1, at least about 0.15:1, at least about 0.175:1, at least about 0.20:1, at least about 0.22:1, at least about 0.25:1, and / or about 0.35 or less:1, about 0.32 or less:1, about 0.30 or less:1, about 0.27 or less:1, about 0.25 or less:1, about 0.22 or less:1, about 0.20 or less:1, about 0.175 or less:1, about 0.15 or less:1, about 0.125 or less:1, and about 0.10 or less:1.

[0057]

[0078] In some embodiments, the core layer 3 may be thinner than one or both of the outer skin layers 1 or 2. For example, over at least about 25 percent, at least about 50 percent, at least about 75 percent, at least about 95 percent, or 100 percent of the total area of ​​the interlayer 10, the core layer 3 may be thinner than at least one (or both) of the outer skin layers 1 or 2. For example, in some embodiments, over at least about 25 percent, at least about 50 percent, at least about 75 percent, at least about 95 percent, or 100 percent of the total area of ​​the interlayer 10, one of the outer skin layers 1 or 2 may be thinner than the other outer skin layer 2 or 1, for example, at least about 10 percent, at least about 15 percent, at least about 20 percent, at least about 25 percent, at least about 30 percent, at least about 35 percent, at least about 40 percent, at least about 45 percent, at least about 50 percent, at least about 55 percent, or at least about 60 percent thicker (or thinner) than the other outer skin layer 2 or 1.

[0058]

[0079] In some embodiments, over at least about 25 percent, at least about 50 percent, at least about 75 percent, at least about 95 percent, or 100 percent of the total area of ​​the interlayer 10, one of the outer skin layers 1 or 2 may be at least about 0.01 mm, at least about 0.025 mm, at least about 0.05 mm, at least about 0.075 mm, at least about 0.1 mm, or at least about 0.15 mm thinner than the other outer skin layer 2 or 1. Additionally or alternatively, one of the skin layers 1 or 2 may be at least about 0.5 mm, at least about 0.45 mm, at least about 0.40 mm, at least about 0.35 mm, at least about 0.30 mm, at least about 0.25 mm, at least about 0.20 mm, or at least about 0.15 mm thinner than the other outer skin layer 2 or 1. This difference in thickness may be an average thickness, a nominal thickness, or, in the case of a wedge-shaped interlayer 10, this difference may be the maximum thickness or the difference in thickness at a specified location.

[0059]

[0080] Referring here to Figures 12a-e, several additional wedge-shaped interlayers 10 configured according to embodiments of the present technology are shown. In particular, in the interlayers shown in Figures 12a-e, the thickness of one of the outer polymer layers (shown as the first polymer layer "1" in Figures 12a-e) may be thicker at the thinnest edge 14 of the tapered region 16 (or interlayer 10) than at the thickest edge 12 of the tapered region 16 (or interlayer 10). In other words, the thicker end of the wedge-shaped first layer 1 may be located at the thinnest edge 14 of the tapered region 16, and the thinner end of the first layer 1 may be located at the thickest edge 12 of the tapered region 16.

[0060]

[0081] Such a configuration is referred to herein as a “reverse wedge” profile. Although described herein in relation to the first polymer layer, it should be understood that the dimensions and configuration of the embodiments of this technology apply similarly to the second layer 2, depending on the configuration of the interlayer.

[0061]

[0082] The additional embodiments of the interlayer 10 shown in Figures 12f to 12g illustrate other embodiments of the present technology, where the entire interlayer is not wedge-shaped (Figure 12f), or all three layers are wedge-shaped, with the thinner end of the core layer 3 located at the tapered region 16 or the thickest edge 14 of the interlayer 10 (Figure 12g).

[0062]

[0083] In one or more embodiments, the thickness of the first polymer layer 1 at the thinnest edge 14 of the tapered region 16 (or interlayer 10) is at least 0.05 mm, at least about 0.10 mm, at least about 0.15 mm, or at least about 0.20 mm, and / or about 0.3 mm or less, about 0.25 mm or less, about 0.20 mm or less, or about 0.15 mm or less than the thickness of the first polymer layer 1 at the thickest edge 12 of the tapered region 16 (or interlayer 10). As a result, the first polymer layer 1 of the interlayer 10 shown in Figures 12a-e generally has an "inverted" wedge-shaped profile.

[0063]

[0084] In some embodiments, as shown in Figures 12a-c, other outer layers (shown as the second polymer layer "2" in Figures 12a-c) may also have a wedge shape and a thickness at the thinnest edge 14 of the tapered region 16 (or interlayer 10) that is thinner than its thickness at the thickest edge 12 of the tapered region 16 (or interlayer 10). In one or more embodiments, the thickness of the second polymer layer 2 at the thinnest edge 14 of the tapered region 16 (or interlayer 10) may be at least 0.05 mm, at least about 0.10 mm, at least about 0.15 mm, or at least about 0.20 mm, and / or about 0.3 mm or less, about 0.25 mm or less, about 0.20 mm or less, or about 0.15 mm or less than the thickness of the second polymer layer 2 at the thickest edge 14 of the tapered region 16 (or interlayer 10). As a result, the second polymer layer 2 may have a wedge-shaped profile similar to that of the tapered region 16 or the overall interlayer 10. In some embodiments, for example, as shown in Figures 12d and 12f, the second polymer layer 2 may be a flat layer with a substantially uniform (non-tapered) profile and substantially constant thickness.

[0064]

[0085] In one or more embodiments, one of the outer polymer layers 1 or 2 may be thinner overall than the other outer polymer layer 2 or 1. For example, one polymer layer 1 or 2 may have an average thickness that is at least about 0.05 mm, at least about 0.075 mm, at least about 0.10 mm, at least about 0.15 mm, or at least about 0.2 mm, and / or about 0.25 mm or less, about 0.20 mm or less, about 0.15 mm or less, about 0.10 mm or less, about 0.075 mm or less, or about 0.05 mm or less, thinner than the average thickness of the other polymer layer 2 or 1. As used herein, the term “average thickness” refers to the thickness of a layer or interlayer, measured at 10 equally spaced positions over the entire vertical height of the interlayer and then averaged (i.e., divided by 10).

[0065]

[0086] In one or more embodiments, the ratio of the mass of the first polymer layer 1 to the total mass of the combined first and second polymer layers 1 or 2 may be at least about 0.10:1, at least about 0.15:1, at least about 0.20:1, at least about 0.25:1, at least about 0.30:1, at least about 0.35:1, at least about 0.40:1, at least about 0.45:1, at least about 0.50:1, and / or about 0.95 or less:1, at least about 0.90:1, at least about 0.85:1, at least about 0.80:1, at least about 0.75:1, at least about 0.70:1, at least about 0.65:1, at least about 0.60:1, at least about 0.55:1, at least about 0.50:1, or at least about 0.45:1.

[0066]

[0087] In one or more embodiments, the thickness of the first polymer layer 1 may be greater than the thickness of the second polymer layer 2 at the thinnest edge 14 of the tapered region 16 (or interlayer 10). For example, the thickness of the first polymer layer 1 at the thinnest edge 14 of the tapered region 16 (or interlayer 10) is at least about 0.005 mm, at least about 0.01 mm, at least about 0.025 mm, at least about 0.05 mm, at least about 0.075 mm, and / or about 0.15 mm or less, about 0.125 mm or less, about 0.15 mm or less, about 0.15 mm or less, or about 0.075 mm or less than the thickness of the second polymer layer 2 at the thinnest edge 14 of the tapered region 16 (or interlayer 10).

[0067]

[0088] In one or more embodiments, the ratio of the thickness of the first polymer layer 1 to the thickness of the second polymer layer 2 at the thinnest edge 14 of the tapered region 16 (or interlayer 10) may be at least about 1.05:1, at least about 1.1:1, at least about 1.2:1, at least about 1.25:1, at least about 1.3:1, at least about 1.35:1, at least about 1.4:1, at least about 1.45:1, or at least about 1.5:1, and / or about 5 or less:1, about 4.5 or less:1, about 4 or less:1, about 3.5 or less:1, about 3 or less:1, about 2.5 or less:1, or about 2 or less:1.

[0068]

[0089] In some embodiments, the ratio of the thickness of the first polymer layer 1 to the thickness of the thinnest edge portion 14 of the tapered region 16 (or interlayer 10) is at least 0.20:1, at least about 0.25:1, at least about 0.30:1, at least about 0.35:1, at least about 0.40:1, at least about 0.45:1, or at least about 0.50:1, and / or 0.85 or less:1, about 0.80 or less:1, about 0.75 or less:1, about 0.70 or less:1, about 0.65 or less:1, about 0.60 or less:1, about 0.55 or less:1, about 0.50 or less:1, about 0.45 or less:1, or about 0.40 or less:1.

[0069]

[0090] In some embodiments, the ratio of the thickness of the second polymer layer 2 to the thickness of the thinnest edge portion 14 of the tapered region 16 (or interlayer 10) is at least about 0.1:1, at least about 0.15:1, at least about 0.20:1, at least about 0.25:1, at least about 0.30:1, at least about 0.35:1, or at least about 0.40:1, and / or 0.45 or less:1, about 0.40 or less:1, about 0.35 or less:1, about 0.30 or less:1, or about 0.25 or less:1.

[0070]

[0091] In some embodiments, the ratio of the thickness of the first polymer layer 1 to the thickness of the second polymer layer 2 at the thinnest edge 14 of the tapered region 16 (or interlayer 10) may be at least about 0.10:1, at least about 0.15:1, at least about 0.20:1, at least about 0.25:1, at least about 0.30:1, at least about 0.35:1, and / or about 0.75 or less:1, about 0.70 or less:1, about 0.65 or less:1, about 0.60 or less:1, about 0.55 or less:1, about 0.50 or less:1, about 0.45 or less:1, about 0.40 or less:1, and about 0.35 or less:1. The ratio of the thickness of the first polymer layer 1 to the thickness of the second polymer layer 2 at the thickest edge 12 of the tapered region 16 (or interlayer 10) may be at least about 0.10:1, at least about 0.15:1, at least about 0.20:1, at least about 0.25:1, at least about 0.30:1, at least about 0.35:1, and / or about 0.75 or less:1, about 0.70 or less:1, about 0.65 or less:1, about 0.60 or less:1, about 0.55 or less:1, about 0.50 or less:1, about 0.45 or less:1, about 0.40 or less:1, or about 0.35 or less:1.

[0071]

[0092] Additionally or alternatively, the thickness of the first polymer layer 1 may be thinner than the thickness of the second polymer layer 2 at the thickest edge 12 of the tapered region 16 (or interlayer 10), as is also generally shown in Figures 12a-e. For example, the thickness of the first polymer layer 1 at the thickest edge 12 of the tapered region 16 (or interlayer 10) may be at least about 0.05 mm, at least about 0.10 mm, at least about 0.15 mm, at least about 0.20 mm, or at least about 0.25 mm, and / or about 0.35 mm or less, about 0.30 mm or less, about 0.25 mm or less, about 0.20 mm or less, about 0.15 mm or less, or about 0.10 mm or less than the thickness of the second polymer layer 2 at the thickest part of the tapered region 16 (or interlayer 10).

[0072]

[0093] In one or more embodiments, the ratio of the thickness of the first polymer layer 1 to the thickness of the second polymer layer 2 at the thickest edge 12 of the tapered region 16 (or interlayer 10) is at least about 0.10:1, at least about 0.15:1, at least about 0.2:1, at least about 0.25:1, at least about 0.30:1, at least about 0.35:1, at least about 0.4:1, at least about 0.5:1, at least about 0.6:1, or at least about 0.75:1, and / or about 0.99 or less:1, about 0.95 or less:1, about 0.90 or less:1, about 0.85 or less:1, about 0.80 or less:1, about 0.75 or less:1, 0.70 or less:1, 0.65 or less:1, 0.55 or less:1, 0.50 or less:1, 0.45 or less:1, 0.40 or less:1, 0.35 or less:1. In one or more embodiments, the ratio of the thickness of the second polymer layer 2 to the thickness of the thickest edge portion 12 of the tapered region 16 (or interlayer 10) is at least about 0.20:1, at least about 0.25:1, at least about 0.30:1, at least about 0.35:1, at least about 0.40:1, at least about 0.45:1, or at least about 0.50:1, and / or about 0.85 or less:1, about 0.80 or less:1, about 0.75 or less:1, about 0.70 or less:1, about 0.65 or less:1, about 0.60 or less:1, about 0.55 or less:1, about 0.50 or less:1, about 0.45 or less:1, or about 0.40 or less:1. In one or more embodiments, the ratio of the thickness of the first polymer layer 1 to the thickness of the thickest edge portion 12 of the tapered region 16 (or interlayer 10) is at least about 0.1:1, at least about 0.15:1, at least about 0.20:1, at least about 0.25:1, at least about 0.30:1, at least about 0.35:1, or at least about 0.40:1, and / or 0.45 or less:1, about 0.40 or less:1, about 0.35 or less:1, about 0.30 or less:1, or about 0.25 or less:1.

[0073]

[0094] Furthermore, in one or more embodiments, the third polymer layer in Figures 12a-d (shown as the innermost layer or core layer "3") may also be a wedge-shaped layer. In one or more embodiments, the thickness of the third polymer layer 3 at the thinnest edge 14 of the tapered region 16 (or interlayer 10) may be less than the thickness of the third polymer layer 3 at the thickest edge 12 of the tapered region 16 (or interlayer 10). Thus, the third polymer layer 3 may also have a wedge-shaped profile similar to the overall profile of the interlayer 10. In some embodiments, as shown in Figure 12a, for example, the third polymer layer 3 may be a flat layer with a substantially uniform (non-tapered) profile.

[0074]

[0095] In one or more embodiments, the ratio of the thickness of the third layer 3 at the thinnest edge 14 of the tapered region 16 (or interlayer 10) to the thickness of the third layer 3 at the thickest edge 12 of the tapered region 16 (or interlayer 10) is at least about 1:1, at least about 1.05:1, at least about 1.1:1, at least about 1.15:1, at least about 1.2:1, at least about 1.25:1, at least about 1.5:1, at least about 2:1, at least about 2.5:1, at least about 3:1, or at least about 3.5:1, and / or about 5 or less:1, about 4.5 or less:1, about 4 or less:1, about 3.5 or less:1, about 3 or less:1, about 2.5 or less:1, about 2 or less:1, about 1.5 or less:1, about 1.25 or less:1, about 1.15 or less:1, or about 1 or less:1, or 1:1.

[0075]

[0096] In one or more embodiments, the ratio of the thickness of the third polymer layer 3 to the total thickness of the thickest edge portion 12 of the tapered region 16 (or interlayer 10) is at least about 0.05:1, at least about 0.10:1, at least about 0.15:1, or at least about 0.20:1, and / or about 0.40 or less:1, about 0.35 or less:1, about 0.30 or less:1, about 0.25 or less:1, about 0.20 or less:1, about 0.15 or less:1, or about 0.10 or less:1. The ratio of the thickness of the third polymer layer 3 to the total thickness of the thinnest edge portion 14 of the tapered region 16 (or interlayer 10) is at least about 0.05:1, at least about 0.10:1, at least about 0.15:1, at least about 0.20:1, at least about 0.25:1, at least about 0.30:1, at least about 0.35:1, at least about 0.40:1, at least about 0.45:1, at least The ratio may be approximately 0.50:1, and / or approximately 0.80 or less:1, approximately 0.75 or less:1, approximately 0.70 or less:1, approximately 0.65 or less:1, approximately 0.60 or less:1, approximately 0.55 or less:1, approximately 0.50 or less:1, approximately 0.45 or less:1, approximately 0.35 or less:1, approximately 0.30 or less:1, approximately 0.25 or less:1, approximately 0.20 or less:1, approximately 0.15 or less:1, or approximately 0.10 or less:1.

[0076]

[0097] In one or more embodiments, the ratio of the thickness of the third polymer layer 3 to the thickness of the first polymer layer 1 at the thinnest edge 14 of the tapered region 16 (or interlayer 10) may be at least about 0.05:1, at least about 0.10:1, at least about 0.15:1, at least about 0.20:1, and / or about 0.50 or less:1, about 0.45 or less:1, about 0.40 or less:1, about 0.35 or less:1, about 0.30 or less:1, about 0.25 or less:1, or about 0.20 or less:1. Additionally or alternatively, the ratio of the thickness of the third polymer layer 3 to the thickness of the first polymer layer 1 at the thickest edge 12 of the tapered region 16 (or interlayer 10) may be at least about 0.40:1, at least about 0.50:1, at least about 0.60:1, at least about 0.70:1, at least about 0.80:1, or at least about 0.90:1, and / or about 5 or less:1, about 4.5 or less:1, about 4 or less:1, about 3.5 or less:1, about 3 or less:1, about 2.5 or less:1, about 2 or less:1, about 1.5 or less:1, about 1.1 or less:1, about 0.90 or less:1, about 0.80 or less:1, about 0.75 or less:1, or about 0.50 or less:1.

[0077]

[0098] In some embodiments, the third layer 3 may have a thickness of at least about 88.9 μm (3.5 mil), at least about 101.6 μm (4 mil), at least about 114.3 μm (4.5 mil), at least about 127 μm (5 mil), and / or about 254 μm (10 mil) or less, about 228.6 μm (9 mil) or less, about 203.2 μm (8 mil) or less, about 177.8 μm (7 mil) or less, about 152.4 μm (6 mil) or less, or about 127 μm (5 mil) or less. In some embodiments, the thicker edges of the third layer 3 are at least about 88.9 μm (3.5 mil), at least about 101.6 μm (4 mil), at least about 114.3 μm (4.5 mil), at least about 127 μm (5 mil), at least about 139.7 μm (5.5 mil), at least about 152.4 μm (6 mil), at least about 165.1 μm (6.5 mil), at least about 177.8 μm (7 mil), at least about 190.5 μm (7.5 mil), and at least about 203.2 μm. (8 mils), or at least about 215.9 μm (8.5 mils), and / or may have a thickness of about 571.5 μm (22.5 mils) or less, about 508 μm (20 mils) or less, about 431.8 μm (17 mils) or less, about 381 μm (15 mils) or less, about 355.6 μm (14 mils) or less, about 330.2 μm (13 mils) or less, about 304.8 μm (12 mils) or less, about 279.4 μm (11 mils) or less, about 254 μm (10 mils) or less, or about 241.3 μm (9.5 mils) or less.If the third layer 3 is flat, it is at least about 88.9 μm (3.5 mil), at least about 101.6 μm (4 mil), at least about 114.3 μm (4.5 mil), at least about 127 μm (5 mil), at least about 139.7 μm (5.5 mil), at least about 152.4 μm (6 mil), at least about 165.1 μm (6.5 mil), at least about 177.8 μm (7 mil), at least about 190.5 μm (7.5 mil), at least about 203.2 μm (8 mil), or at least about 215.9 μm (8.5 mil), and / or about 571.5 μm It may have an average thickness of m (22.5 mils) or less, approximately 508 μm (20 mils) or less, approximately 431.8 μm (17 mils) or less, approximately 381 μm (15 mils) or less, approximately 355.6 μm (14 mils) or more, approximately 330.2 μm (13 mils) or less, approximately 304.8 μm (12 mils) or less, approximately 279.4 μm (11 mils) or less, approximately 254 μm (10 mils) or less, approximately 241.3 μm (9.5 mils) or less, approximately 228.6 μm (9 mils) or less, approximately 203.2 μm (8 mils) or less, approximately 177.8 μm (7 mils) or less, approximately 152.4 μm (6 mils) or less, or approximately 127 μm (5 mils) or less.

[0078]

[0099] Figure 8 shows the thickness profiles of the interlayer 10 according to various embodiments of the technology. In some embodiments, as an example is shown in Figure 8, at least one (or both) of the outer layers 1 or 2 of the interlayer may have a thickness that does not exceed a certain maximum thickness within a set distance from one of the edges of the interlayer. For example, in some embodiments, the thickness of at least one of the outer layers 1 or 2 shall not exceed 0.3 mm within about 40 cm of the thinnest edge 14 of the interlayer, as graphically shown in Figure 8 and schematically shown in Figure 6 (as an interlayer) and Figure 7 (as a laminated glazing or windshield).

[0079] [000100] In some cases, the maximum thickness of at least one of the outer layers 1 or 2 shall not exceed 0.30 mm, 0.29 mm, 0.28 mm, 0.27 mm, 0.26 mm, or 0.25 mm within approximately 10 cm, 20 cm, 30 cm, or 40 cm of the thinnest edge 14 of the tapered region 16 (or interlayer 10). In some cases, the maximum thickness of at least one of the outer layers 1 or 2 shall not exceed 0.30 mm within at least approximately 45 cm, at least approximately 50 cm, at least approximately 55 cm, at least approximately 60 cm, at least approximately 65 cm, at least approximately 70 cm, at least approximately 75 cm, or at least approximately 80 cm of the thinnest edge 14 of the tapered region 16 (or interlayer 10). These ranges may also apply when the interlayer 10 is used to form the windshield 20 and the thinnest edge 14 is located at the bottom (vertically mounted) edge, as is commonly shown in Figure 7.

[0080] [000101]Looking at Figure 9, the thickness profiles of at least one (or both) of the outer skin layers are shown graphically, with the minimum and maximum thicknesses illustrated as a function of position. More specifically, Figure 9 provides a graphical representation of the maximum thickness (Tmax) and the minimum thickness (Tmin) of the same outer layer applicable to at least one of the outer skin layers. Thus, the shaded area between the curves shown in Figure 9 represents the range of possible thicknesses of the outer layer as a function of the position of the first 100 cm of the interlayer, measured from the thinnest edge.

[0081] [000102] As shown in Figure 9, the maximum thickness (Tmax) of the outer skin layer as a function of the distance from the thinnest edge can be expressed by the following equation (1): Tmax=1.975141-(1.6936517) / (1+(De / 155.2664)^3.324064) (1) [000103]In the formula, D e This is the distance (in cm) from the thinnest edge of the interlayer.

[0082] [000104] Similarly, the minimum thickness of the outer skin layer, expressed as a function of the distance from the thinnest edge, can be expressed by the following equation (II): Tmin = 0.0014De + 0.06 (II) [000105]In the formula, D e is the distance (in cm) from the thinnest edge of the interlayer. Alternatively or additionally, the minimum thickness of the outer skin layer can also be expressed by one of the following other equations (III) and (IV): Tmin = 0.0024De + 0.06 (III) Tmin = 0.002De + 0.10 (IV) [000106]In the formula, D e is the distance (in cm) from the thinnest edge of the interlayer. From equation (II), the terms in (IV) below it are possible equations that represent the lower line showing Tmin of the thickness profile shown in Figure 9, while equation (I) represents the upper line of Tmax as a function of position.

[0083] [000107] In some embodiments, at least one (or both) of the outer skin layers has a thickness profile defined by the following formula (V): [0.0024(D e )+0.06] <T1<[1.975141-(1.6936517) / (1+(D e / 155.2664)^3.324064)] (V) [000108][where D e This is the distance (in cm) from the thinnest edge of the interlayer, and T1 is D e It may have the thickness (in mm) of the first layer in [the diagram]. This corresponds to the shaded area in Figure 9.

[0084] [000109] Now looking at Figure 13, another embodiment of the wedge-formed interlayer 10 according to an art embodiment of the present invention is provided. The wedge-formed interlayer 10 shown in Figure 13 comprises a pair of skin layers (first and second layers 1 or 2) and a core layer (third layer 3). As stated above, the use of “first,” “second,” “third,” etc., is solely for the purpose of facilitating the discussion herein and is not intended to be limiting unless otherwise indicated.

[0085] [000110] As shown in Figure 13, the wedge-formed interlayer 10 has the following relationship at all points along the vertical centerline (shown as the dashed line Z-Z' in Figure 13) extending between the thinnest and thickest edges 14, 12: 1.25Tca > TcL > 0.75Tca [In the formula, TcL is the local combined thickness of the first and second layers, and Tca is the average combined thickness of the first and second layers, calculated as follows: Tca = (Tc1 + Tc2) / 2 In the formula, Tc1 is the combined thickness of the first and second layers 1 or 2 at the thinnest edge 14, and Tc2 is the combined thickness of the first and second layers 1 or 2 at the thickest edge 12. The structure may be configured to satisfy this condition. As illustrated in Figure 13, Tc1 is calculated by adding the thickness of the first layer 1 at the thinnest edge 14 (indicated as T1s1) and the thickness of the second layer 2 at the thinnest edge 14 (indicated as T2s1), while Tc2 is calculated by adding the thickness of the first layer 1 at the thickest edge 12 (indicated as T1s2) and the thickness of the second layer 2 at the thickest edge 12 (indicated as T2s2). The formulas for Tc1 and Tc2 are shown below.

[0086] Tc1=T1s1+T2s1 (thinnest edge) Tc2=T1s2+T2s2 (thickest edge) [000111] For example, the combined local thicknesses of the first and second layers 1 or 2 at arbitrarily selected points X, Y, and Z, respectively (indicated as TcLX, TcLY, and TcLZ in Figure 13) fall within the ranges of 1.25 Tca and 0.75 Tca, respectively, where Tca is as defined above. Thus, in some embodiments, despite variations in the thickness of individual skin layers at various positions along the vertical centerline of the interlayer, the combined thickness remains substantially constant and substantially similar to the average of the combined thicknesses at both ends of the tapered region 16 (or interlayer 10).

[0087] [000112] In some embodiments, Tca may be at least about 635 μm (25 mil), at least about 685.8 μm (27 mil), at least about 762 μm (30 mil), at least about 812.8 μm (32 mil), at least about 863.6 μm (34 mil), at least about 889 μm (35 mil), at least about 914.4 μm (36 mil), and / or less than or equal to about 1143 μm (45 mil), less than or equal to about 1066.8 μm (42 mil), less than or equal to about 101 μm (40 mil), less than or equal to about 965.2 μm (38 mil), less than or equal to about 939.8 μm (37 mil), or less than or equal to about 889 μm (35 mil). The values ​​of Tc1 and Tc2 shown in Figure 13, as well as the combined thickness values ​​of skin layer 1 or 2 along the vertical centerline, also fall within one or more ranges provided herein.

[0088] [000113] In some embodiments, the average combined thickness (Tcavg) of the first and second layers 1 or 2 taken at 10 (20, 30, 40, 50 or 60) points that are equally spaced between the thinnest and thickest edges 14, 12 of the tapered region 16 can satisfy the following equation: 1.25Tcavg > TcL > 0.75Tcavg In the formula, TcL is the local combined thickness of the first and second layers 1 or 2. In some embodiments, the higher boundary values ​​of the above range may be 1.2Tcavg or less, 1.15Tcavg, 1.1Tcavg, or 1.05Tcavg. In some embodiments, the lower boundary values ​​of the range may be at least 0.80cavg, 0.85Tcavg, 0.90Tcavg, or 0.95Tcavg. In some embodiments, the above equation can be satisfied at all points between the thinnest and thickest edges 14, 12 of the tapered region 16.

[0089] [000114] Each layer of the multilayer interlayer may be formed from at least one thermoplastic polymer. Examples of suitable thermoplastic polymers include, but are not limited to, poly(vinyl acetal) resins, polyurethane (PU), poly(ethylene-co-vinyl acetate) (EVA), polyvinyl chloride (PVC), poly(vinyl chloride-co-methacrylate), polyethylene, polyolefin, ethylene acrylate ester copolymer, poly(ethylene-co-butyl acrylate), silicone elastomer, epoxy resin, and acid copolymers derived from any of the polymers listed above, such as ethylene / carboxylic acid copolymers and their ionomers, as well as combinations thereof. In some embodiments, the thermoplastic polymer may be selected from the group consisting of poly(vinyl acetal) resins, polyvinyl chloride, and polyurethane, or the resin may include one or more poly(vinyl acetal) resins. While poly(vinyl acetal) resins, particularly poly(vinyl butyral) resins, are described herein, it should be understood that one or more of the above polymer resins may be included together with, or in place of, the poly(vinyl acetal) resins described below in various embodiments of the present invention.

[0090] [000115] If the resin compositions, layers and interfilms described herein include a poly(vinyl acetal) resin, the poly(vinyl acetal) resin may be formed by any suitable method. The poly(vinyl acetal) resin can be formed by acetalizing polyvinyl alcohol with one or more aldehydes in the presence of an acid catalyst. The resulting resin can then be separated, stabilized and dried according to known methods, for example, U.S. Patent Nos. 2,282,057 and 2,282,026, and Wade, B. 2016, Vinyl Acetal Polymers, Encyclopedia of Polymer Science and Technology, pp. 1-22 (online, copyright 2016 John Wiley & Sons, Inc.). The resulting poly(vinyl acetal) resin may have a total acetalization percentage of at least about 50 wt%, at least about 60 wt%, at least about 70 wt%, at least about 75 wt%, at least about 80 wt%, or at least about 85 wt%, as measured according to ASTM D-1396 unless otherwise specified. The total amount of aldehyde residues in the poly(vinyl acetal) resin can be collectively referred to as the acetal components, and the remainder of the poly(vinyl acetal) resin consists of residual vinyl alcohol (hydroxyl) and residual acetate groups, which are discussed in more detail below.

[0091] [000116] In some embodiments, at least one or all layers in a multilayer interlayer may contain at least about 0.5 weight percent, at least about 1 weight percent, at least about 2 weight percent, at least about 3 weight percent, at least about 5 weight percent, at least about 10 weight percent, at least about 15 weight percent, at least about 20 weight percent, at least about 30 weight percent, at least about 40 weight percent, at least about 45 weight percent, or at least about 50 weight percent, based on the combined weight of all resins in the layer. The at least one poly(vinyl acetal) resin may constitute at least about 10 weight percent, at least about 20 weight percent, at least about 30 weight percent, at least about 40 weight percent, at least about 50 weight percent, at least about 60 weight percent, at least about 70 weight percent, or at least about 80 weight percent of the layer, based on the combined weight of all resins. In some embodiments, the amount of resins other than at least one poly(vinyl acetal) resin may be about 20% by weight or less, about 15% by weight or less, about 10% by weight or less, about 5% by weight or less, about 2% by weight or less, or about 1% by weight, based on the combined weight of all resins. In some cases, the layer may contain a single poly(vinyl acetal) resin, while in other cases, it may contain a blend of two or more. The composition of each layer of the multilayer interfilm may be the same, or one or more layers may differ from at least one other layer in the interfilm.

[0092] [000117] The poly(vinyl acetal) resin used in the layers of the multilayer interlayer can contain any suitable aldehyde residues, and in some embodiments, at least one C1-C 10The aldehyde may contain at least one C4-C8 aldehyde residue. Suitable examples of C4-C8 aldehydes may include, but are not limited to, n-butyraldehyde, iso-butyraldehyde, 2-methylbarrelaldehyde, n-hexylaldehyde, 2-ethylhexylaldehyde, n-octylaldehyde, and combinations thereof. In some embodiments, the poly(vinyl acetal) resin used in the layer may contain at least about 20 weight percent, at least about 30 weight percent, at least about 40 weight percent, at least about 50 weight percent, at least about 60 weight percent or at least about 70 weight percent of at least one C4-C8 aldehyde residue, and / or at least 90 weight percent or less, at least about 85 weight percent or less, at least about 80 weight percent or less, at least about 75 weight percent or less, at least 70 weight percent or at least one C4-C8 aldehyde, or at least 65 weight percent or less of at least one C4-C8 aldehyde in the range of about 20 to about 90 weight percent, in the range of about 30 to about 80 weight percent or in the range of about 40 to about 70 weight percent. The C4-C8 aldehyde may be selected from the groups listed above, or from the group consisting of n-butyraldehyde, iso-butyraldehyde, 2-ethylhexylaldehyde, and combinations thereof.

[0093] [000118] In some embodiments, the poly(vinyl acetal) resin may be polyvinyl butyral (PVB) resin. In other embodiments, the poly(vinyl acetal) resin may be a poly(vinyl n-butyral) resin mainly containing n-butyraldehyde residues, and may contain, for example, about 50% by weight or less, about 40% by weight or less, about 30% by weight or less, about 20% by weight or less, about 10% by weight or less, about 5% by weight or less, or about 2% by weight or less of aldehyde residues other than n-butyraldehyde, based on the total weight of all aldehyde residues in the resin.

[0094] [000119] When poly(vinyl acetal) resin includes PVB resin, the molecular weight of the resin may be at least about 50,000 daltons, about 70,000 daltons, about 100,000 daltons, and / or less than or equal to about 600,000 daltons, about 550,000 daltons, about 500,000 daltons, about 450,000 daltons, or about 425,000 daltons, as used herein, mean weight-average molecular weight (M w This refers to poly(vinyl acetal) resin. The molecular weight of poly(vinyl acetal) resin can range from approximately 50,000 to 600,000 daltons, 70,000 to 450,000 daltons, or 100,000 to 425,000 daltons.

[0095] [000120] According to some embodiments, two or more layers of the multilayer interlayer can have different compositions. For example, in some embodiments, one or both of the outer skin layers may be formed from a first poly(vinyl acetal) resin, while the core or inner layer may be formed from a second poly(vinyl acetal) resin. In some embodiments, the poly(vinyl acetal) resin used to form the first layer may have a residual hydroxyl content and / or residual acetate content that is at least about 2 weight percent, at least about 3 weight percent, at least about 4 weight percent, at least about 5 weight percent, at least about 6 weight percent, or at least about 8 weight percent higher or lower than the residual hydroxyl content and / or residual acetate content of the second poly(vinyl acetal) resin used to form the second layer.

[0096] [000121]As used herein, the terms “residual hydroxyl content” and “residual acetate content” refer to the amounts of hydroxyl groups and acetate groups, respectively, that remain after processing is complete. For example, polyvinyl n-butyral can be produced by hydrolyzing polyvinyl acetate to polyvinyl alcohol, and then acetalizing the polyvinyl alcohol with n-butyraldehyde to form polyvinyl n-butyral. In the hydrolysis of polyvinyl acetate, not all acetate groups are converted to hydroxyl groups, and residual acetate groups remain in the resin. Similarly, in the acetalization of polyvinyl alcohol, not all hydroxyl groups are converted to acetal groups, and this also leaves residual hydroxyl groups in the resin. As a result, most poly(vinylacetal) resins contain both residual hydroxyl groups (as vinyl hydroxyl groups) and residual acetate groups (as vinyl acetate groups) as part of the polymer chain. The residual hydroxyl content and residual acetate content are based on the weight of the polymer resin and are expressed as weight percentages measured according to ASTM D-1396 unless otherwise specified.

[0097] [000122] In some cases, the difference in the residual hydroxyl content of poly(vinyl acetal) resin in two or more layers (e.g., the first and third, and / or the second and third) may also be at least about 2 weight percent, at least about 5 weight percent, at least about 10 weight percent, at least about 12 weight percent, at least about 15 weight percent, at least about 20 weight percent, or at least about 30 weight percent. As used herein, the terms “weight percentage difference” or “the difference of… is at least… weight percent” refer to the difference between two given weight percentages calculated by subtracting one number from another. For example, a poly(vinyl acetal) resin having a residual hydroxyl content of 12 weight percent has a residual hydroxyl content that is 2 weight percent lower (14 weight percent - 12 weight percent = 2 weight percent) than a poly(vinyl acetal) resin having a residual hydroxyl content of 14 weight percent. As used herein, the terms “there is a difference” may refer to a value that is higher or lower than another value.

[0098] [000123] At least one poly(vinyl acetal) resin used in one or more polymer layers is at least about 14% by weight, at least about 14.5% by weight, at least about 15% by weight, at least about 15.5% by weight, at least about 16% by weight, at least about 16.5% by weight, at least about 17% by weight, at least about 17.5% by weight, at least about 18% by weight, at least about 18.5% by weight, at least about 19% by weight, at least about 19.5% by weight, and / or about 45% by weight or less, about 40% by weight or less, about 35% by weight or less, about 3 The residual hydroxyl content may be 3% by weight or less, approximately 30% by weight or less, approximately 27% by weight or less, approximately 25% by weight or less, approximately 24% by weight or less, approximately 23.5% by weight or less, approximately 23% by weight or less, approximately 22.5% by weight or less, approximately 22% by weight or less, approximately 21.5% by weight or less, approximately 21% by weight or less, approximately 20.5% by weight or less, or approximately 20% by weight or less, or in the range of approximately 14 to approximately 45% by weight, approximately 16 to approximately 30% by weight, approximately 18 to approximately 25% by weight, approximately 18.5 to approximately 20% by weight, or approximately 19.5 to approximately 21% by weight.

[0099] [000124] Another poly(vinyl acetal) resin used in one or more layers of the interlayer film is at least about 8 weight percent, at least about 9 weight percent, at least about 10 weight percent, at least about 11 weight percent, and / or about 30 weight percent or less, about 29 weight percent or less, about 28 weight percent or less, about 27 weight percent or less, about 26 weight percent or less, about 25 weight percent or less, about 24 weight percent or less, about 23 weight percent or less, about 22 weight percent or less, about 21 weight percent or less, about 20 weight percent or less, about 19 weight percent or less, about 19.5 weight percent or less, about 18 weight percent or less, about 17.5 weight percent or less, about 17 weight percent or less, about 16. The residual hydroxyl content can be 5% by weight or less, about 16% by weight or less, about 15% by weight or less, about 14.5% by weight or less, about 13% by weight or less, about 11.5% by weight or less, about 11% by weight or less, about 10.5% by weight or less, about 10% by weight or less, about 9.5% by weight or less, or about 9% by weight or less, or in the range of about 8 to about 16% by weight, in the range of about 9 to about 15% by weight, or in the range of about 9.5 to about 14.5% by weight, and the difference in residual hydroxyl content of the poly(vinyl acetal) resins used to form two or more polymer layers can be selected to be at least about 2% by weight, or within one or more of the aforementioned ranges.

[0100] [000125] In some embodiments, for example, at least one poly(vinyl acetal) resin used to form two different layers in the interlayer may have a different residual acetate content from the other. For example, in some embodiments, the difference (or maximum difference) in the residual acetate content of two poly(vinyl acetal) resins (or any of the layers in the interlayer) may be at least about 2 percent, at least about 3 percent, at least about 4 percent, at least about 5 percent, at least about 8 percent, at least about 10 percent, and / or about 15 percent or less, about 13 percent or less, about 10 percent or less, about 8 percent or less, about 6 percent or less, about 4 percent or less, about 2 percent or less, about 1 percent or less, or about 0.5 percent or less. One of the poly(vinyl acetal) resins may have a residual acetate content of less than 15 weight percent, about 13 weight percent or less, about 12 weight percent or less, about 10 weight percent or less, about 8 weight percent or less, about 6 weight percent or less, about 5 weight percent or less, about 4 weight percent or less, about 3 weight percent or less, about 2 weight percent or less, about 1 weight percent or less, or about 0.5 weight percent or less, as measured as described above.

[0101] [000126] In some embodiments, at least one poly(vinyl acetal) resin used to form the interlayer can have a residual acetate content of at least about 5 weight percent, at least about 8 weight percent, at least about 10 weight percent, at least about 12 weight percent, at least about 14 weight percent, at least about 16 weight percent, at least about 18 weight percent, at least about 20 weight percent, or at least about 30 weight percent. The difference in the residual acetate content of the poly(vinyl acetal) resins used in two or more polymer layers can be within the range provided above, or the difference can be less than about 3 weight percent, about 2 weight percent or less, about 1 weight percent or less, or about 0.5 weight percent or less.

[0102] [000127] In some embodiments, the difference in residual hydroxyl content of poly(vinyl acetal) resins used in two or more layers may be less than about 2 weight percent, less than or equal to about 1 weight percent, or less than or equal to about 0.5 weight percent, and the difference in residual acetate content of poly(vinyl acetal) resins used in two or more layers may be at least about 3 weight percent, at least about 5 weight percent, at least about 8 weight percent, at least about 15 weight percent, at least about 20 weight percent, or at least about 30 weight percent. In other embodiments, the difference in residual acetate content of poly(vinyl acetal) resins used in two or more layers may be less than about 3 weight percent, less than or equal to about 2 weight percent, less than or equal to about 1 weight percent, or less than or equal to about 0.5 weight percent, and the difference in residual hydroxyl content of the same poly(vinyl acetal) resin used in two or more layers may be at least about 2 weight percent, at least about 5 weight percent, at least about 10 weight percent, at least about 12 weight percent, at least about 15 weight percent, at least about 20 weight percent, or at least about 30 weight percent.

[0103] [000128] In various embodiments, the difference in the residual hydroxyl and / or residual acetate content of poly(vinyl acetal) resin in two or more polymer layers, for example, including a skin layer and a core layer, may be selected to control or provide certain performance characteristics, such as strength, impact resistance, penetration resistance, processability, or acoustic performance, in the final composition, layer, or interlayer. For example, poly(vinyl acetal) resins with a high residual hydroxyl content, typically exceeding about 16 weight percent, can promote high impact resistance, penetration resistance, and strength in the resin composition or layer, while low hydroxyl content resins, typically having a residual hydroxyl content of less than 16 weight percent, can improve the acoustic performance of the composition or layer.

[0104] [000129] One or more layers of the multilayer interlayer may also contain at least one plasticizer. Depending on the specific composition of the layer, the plasticizer may be at least 5 phr (parts per 100 parts of resin), at least 10 phr, at least 15 phr, at least 20 phr, at least 25 phr, at least 30 phr, at least 35 phr, at least 40 phr, at least 45 phr, at least 50 phr, at least 55 phr, at least 60 phr, and / or 120 phr or less, or about 110 phr or less. It may be present in amounts of approximately 105 phr or less, approximately 100 phr or less, approximately 95 phr or less, approximately 90 phr or less, approximately 85 phr or less, approximately 75 phr or less, approximately 70 phr or less, approximately 65 phr or less, approximately 60 phr or less, approximately 55 phr or less, approximately 50 phr or less, approximately 45 phr or less, or approximately 40 phr or less, or in the range of approximately 5 to approximately 120 phr, approximately 10 to approximately 110 phr, approximately 20 to approximately 90 phr, or approximately 25 to approximately 75 phr.

[0105] [000130] As used herein, the term “parts per 100 parts of resin” or “phr” refers to the amount of plasticizer present, compared to 100 parts of resin on a weight basis. For example, if 30 grams of plasticizer are added to 100 grams of resin, the plasticizer will be present in an amount of 30 phr. If a layer contains two or more resins, the amount of plasticizer is determined by comparing it to the combined amount of all resins present to determine the parts per 100 parts of resin. Furthermore, where the plasticizer content of a layer is presented herein, it is presented with reference to the amount of plasticizer in the mix or melt used to manufacture the layer.

[0106] [000131] Examples of suitable plasticizers may include, but are not limited to, triethylene glycol di-(2-ethylhexanoate) ("3GEH"), triethylene glycol di-(2-ethylbutyrate), triethylene glycol diheptanoate, tetraethylene glycol diheptanoate, tetraethylene glycol di-(2-ethylhexanoate) ("4GEH"), dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, di(butoxyethyl) adipate, and bis(2-(2-butoxyethoxy)ethyl) adipate, dibutyl sebacate, dioctyl sebacate, and mixtures thereof. The plasticizer may be selected from the group consisting of triethylene glycol di-(2-ethylhexanoate) and tetraethylene glycol di-(2-ethylhexanoate), or the plasticizer may contain triethylene glycol di-(2-ethylhexanoate).

[0107] [000132] In some embodiments, the plasticizer contained in one or more layers may be a high-RI plasticizer. As used herein, the term “high-RI plasticizer” means a plasticizer having a refractive index of at least 1.460 as measured by ASTM D542 at a wavelength of 589 nm and a temperature of 25 °C. When used, a high-RI plasticizer may have a refractive index of at least about 1.470, at least about 1.480, at least about 1.490, at least about 1.500, at least about 1.510, at least about 1.520, and / or about 1.600 or less, about 1.575 or less, or about 1.550 or less as measured as considered above.

[0108] [000133] Examples of types or classes of high-RI plasticizers may include, but are not limited to, polyadipates (RI about 1.460 to about 1.485), epoxides, such as epoxide-treated soybean oil (RI about 1.460 to about 1.480), phthalates and terephthalates (RI about 1.480 to about 1.540), benzoates and toluates (RI about 1.480 to about 1.550), and other special plasticizers (RI about 1.490 to about 1.520). Examples of suitable RI plasticizers include dipropylene glycol dibenzoate, tripylene glycol dibenzoate, polypropylene glycol dibenzoate, isodecyl benzoate, 2-ethylhexyl benzoate, diethylene glycol benzoate, butoxyethyl benzoate, butoxyethoxyethyl benzoate, butoxyethoxyethoxyethyl benzoate, propylene glycol dibenzoate, 2,2,4-trimethyl-1,3-pentanediol dibenzoate, 2,2,4-trimethyl-1,3-pentanediol Dibenzoate isobutyrate, 1,3-butanediol dibenzoate, diethylene glycol di-o-toluate, triethylene glycol di-o-toluate, dipropylene glycol di-o-toluate, 1,2-octyl dibenzoate, tri-2-ethylhexyl trimellitate, di-2-ethylhexyl terephthalate, bis-phenol A bis(2-ethylhexanate), di-(butoxyethyl) terephthalate, di-(butoxyethyl) terephthalate, and mixtures thereof may include, but are not limited to, these. High RI plasticizers may be selected from dipropylene glycol dibenzoate and tripropylene glycol dibenzoate, and / or 2,2,4-trimethyl-1,3-pentanediol dibenzoate.

[0109] [000134] When the polymer layer or interlayer contains a high RI plasticizer, the plasticizer may be present in the layer alone or blended with one or more additional plasticizers. The other plasticizers may also contain a high RI plasticizer, or one or more may be low RI plasticizers having a refractive index of less than 1.460. In some embodiments, the low RI plasticizer may have a refractive index of less than about 1.450, less than about 1.445, or less than about 1.442, and may be selected from the group enumerated above. When a mixture of two or more plasticizers is used, the mixture may have one or more refractive indices within the above ranges.

[0110] [000135] Poly(vinyl acetal) resins having high or low residual hydroxyl content and / or residual acetate content may also ultimately contain different amounts of plasticizer when combined with at least one plasticizer. As a result, layers formed from poly(vinyl acetal) resins having different compositions may also have different properties within a single interlayer. Without being bound by theory, it is assumed that the compatibility of a given plasticizer with a poly(vinyl acetal) resin may depend at least in part on the composition of the polymer, particularly the residual hydroxyl content. Overall, poly(vinyl acetal) resins having high residual hydroxyl content tend to exhibit lower compatibility (or acceptance) with a given plasticizer compared to similar resins having low residual hydroxyl content. As a result, poly(vinyl acetal) resins having high residual hydroxyl content tend to be less plasticized and exhibit higher hardness than similar resins having low residual hydroxyl content. Conversely, poly(vinyl acetal) resins with low residual hydroxyl content may tend to incorporate a large amount of plasticizer when plasticized with a given plasticizer, which can result in a flexible polymer layer exhibiting a lower glass transition temperature than similar resins with high residual hydroxyl content. Depending on the specific resin and plasticizer, these tendencies can be reversed.

[0111] [000136] In some embodiments, the interlayer may include a skin layer comprising a poly(vinyl acetal) resin and a plasticizer, and a core or inner polymer layer comprising a poly(vinyl acetal) resin and a plasticizer. The plasticizers in the skin layer and the core layer may be of the same type, or the plasticizers may be different. In some embodiments, at least one of the plasticizers may also be a blend of two or more plasticizers. In some embodiments, the core layer may also contain the same or different plasticizers as the plasticizers in the skin layer. Additionally, in some embodiments, the two outer skin layers may have substantially the same or identical composition (including the type and amount of plasticizers) as each other.

[0112] [000137] If one of the skin layer and the core layer contains a poly(vinyl acetal) resin having a residual hydroxyl content that is at least 2 weight percent higher or lower than the residual hydroxyl content of the poly(vinyl acetal) resin in the other layer, the difference in plasticizer content between the two or more polymer layers may be at least about 2 phr, at least about 5 phr, at least about 8 phr, at least about 10 phr, at least about 12 phr, or at least about 15 phr, at least about 20 phr, at least about 25 phr, at least about 30 phr, or at least about 35 phr. In most embodiments, polymer layers containing resins with a low hydroxyl content can have a high plasticizer content. To control or maintain other properties of the polymer layer or interlayer, the difference in plasticizer content between the two layers may be about 75 phr or less, about 70 phr or less, about 65 phr or less, about 60 phr or less, about 55 phr or less, about 50 phr or less, about 45 phr or less, about 40 phr or less, about 30 phr or less, about 25 phr or less, about 20 phr or less, or about 17 phr. In other embodiments, the difference in plasticizer content between the two polymer layers may be at least about 40 phr, at least about 50 phr, at least about 60 phr, or at least about 70 phr. In some embodiments, the outer skin layer (e.g., the first and second layers) may have a lower plasticizer content than the inner core layer (e.g., the third layer).

[0113] [000138] As a result, in some embodiments, at least two of the polymer layers may exhibit different glass transition temperatures. gThis is the temperature at which a polymer transitions from a glassy state to a rubbery state. The glass transition temperatures of the layers described herein were determined by dynamic mechanical thermal analysis (DMTA). DMTA measures the storage (elastic) coefficient (G') (Pascals), loss (viscosity) coefficient (Pascals) (G"), and tan delta (G'' / G') of the specimen as a function of temperature at a given vibration frequency and temperature sweep rate. The glass transition temperature is then determined by the position of the tan delta peak on the temperature scale. The glass transition temperatures presented herein were determined under shear mode at a vibration frequency of 1 Hz and a temperature sweep rate of 3 °C / min.

[0114] [000139] The difference between the glass transition temperatures of the two layers (e.g., one of the outer layers and the core layer) may be at least about 2°C, at least about 3°C, at least about 5°C, at least about 8°C, at least about 10°C, at least about 12°C, at least about 15°C, at least about 18°C, at least about 20°C, at least about 22°C, at least about 25°C, at least about 30°C, or at least about 35°C, and / or less than or equal to about 50°C, less than or equal to about 45°C, less than or equal to about 40°C, less than or equal to about 35°C, less than or equal to about 30°C, or less than or equal to about 25°C. One layer (e.g., the skin layer) may have a glass transition temperature of at least about 26°C, at least about 28°C, at least about 30°C, at least about 33°C, at least about 35°C, and / or about 70°C or less, about 65°C or less, about 60°C or less, about 55°C or less, about 50°C or less, about 45°C or less, about 40°C or less, about 35°C or less, about 30°C, or about 25°C or less, or in the range of about 26 to about 70°C, about 30 to about 60°C, or about 35 to about 50°C. The other layer (e.g., the core layer) may have a glass transition temperature of 25°C or less, about 20°C or less, about 15°C or less, about 10°C or less, about 5°C or less, about 0°C or less, about -5°C or less, or about -10°C or less.

[0115] [000140] In some cases, the outer layer of the multilayer interlayer may have a higher Tg and may therefore be considered a “hard” outer layer, while the inner layer of the multilayer interlayer may have a lower Tg and may be considered a “soft” interlayer. In some embodiments, the outer skin layer may have a Tg at least about 2°C, at least about 5°C, at least about 10°C, at least about 15°C, at least about 20°C, at least about 25°C, at least about 30°C, or at least about 35°C and / or about 100°C or less, about 90°C or less, about 75°C or less, about 70°C or less, about 65°C or less, about 60°C or less, about 55°C or less, about 50°C or less, about 45°C, or about 40°C or less, about 35°C or less, about 30°C or less, or about 25°C or less higher than the Tg of the inner core layer.

[0116] [000141] In some embodiments, the interlayer may include one or more polymer films in addition to one or more polymer layers present in the interlayer. As used herein, the term “polymer film” refers to a relatively thin, often rigid polymer that imparts certain functionality or performance enhancements to the interlayer. The term “polymer film” differs from the “polymer layer” or “polymer sheet” described herein in that the polymer film does not, in itself, provide the required penetration resistance and glass retention properties to the multilayer panel, but rather provides performance enhancements, such as infrared absorption or reflectivity.

[0117] [000142]Poly(ethylene terephthalate) or "PET" may be used to form the polymer film, and ideally the polymer film used in the various embodiments is optically transparent. A polymer film suitable for use in a particular embodiment may also be formed from other materials, including various metallic materials, metal oxide materials, or other non-metallic materials, and may be coated or otherwise surface-treated. The polymer film may have a thickness of at least about 0.013 mm, at least about 0.015 mm, at least about 0.020 mm, at least about 0.025 mm, at least about 0.030 mm, or at least about 0.040 mm, and / or about 0.060 mm or less, about 0.050 mm or less, about 0.045 mm or less, or about 0.035 mm or less. Other types of functional polymer films may include, but are not limited to, IR reduction layers, holographic layers, photochromic layers, electrochromic layers, antilacerative layers, heat strips, antennas, solar radiation shielding layers, decorative layers, and combinations thereof.

[0118] [000143] In addition, one or more layers of the multilayer interfilm may contain at least one additive that can impart specific properties or characteristics to the polymer layer or interfilm. Such additives may 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) and cesium tungsten oxide, processing aids, flow-enhancing additives, lubricants, impact modifiers, nucleating agents, thermal stabilizers, UV absorbers, dispersants, surfactants, chelating agents, coupling agents, adhesives, primers, reinforcing additives, and fillers. In addition, various adhesion control agents ("ACAs") may be used in one or more polymer layers to control the adhesion of the layer or interfilm to the glass sheet. The specific type and amount of such additives may be selected based on the final properties or end-use of a particular interfilm, and the additives may be used in an extent that does not adversely affect the final properties of the interfilm or the final properties of the windshield utilizing the interfilm configured for a particular application.

[0119] [000144] In some embodiments, one or more layers of the interlayer may contain an infrared (IR) absorbent (or IR-absorbing particles). In some cases, only one of the layers (the first, second, or third) may contain the IR absorbent, while in other embodiments, two or more layers may contain the IR absorbent. If present in two or more layers, the IR absorbent may be the same or different in each layer, and the amount of IR absorbent in each layer may be the same (i.e., within the range of about 0.0050 wt%) or different (i.e., within the range of more than 0.0050 wt%). In some embodiments, the IR absorbent may be present in the core layer. In some embodiments, the IR absorbent may be present in one or both of the outer skin layers.

[0120] [000145] Overall, the IR absorber may be present in the interlayer in an amount of at least about 0.01 weight percent, at least about 0.05 weight percent, at least about 0.10 weight percent, at least about 0.20 weight percent, at least about 0.25 weight percent, at least about 0.30 weight percent, at least about 0.35 weight percent, at least about 0.40 weight percent, at least about 0.45 weight percent, at least about 0.50 weight percent, and / or about 0.75 weight percent or less, about 0.70 weight percent or less, about 0.65 weight percent or less, about 0.60 weight percent or less, about 0.55 weight percent or less, about 0.50 weight percent or less, about 0.45 weight percent or less, about 0.40 weight percent or less, about 0.35 weight percent or less, about 0.30 weight percent or less, about 0.25 weight percent or less, about 0.20 weight percent or less, about 0.15 weight percent or less, or about 0.10 weight percent or less, based on the total weight of the interlayer. When used herein, the quantity is calculated as an average quantity based on the total weight of the sample, layer, or interlayer.

[0121] [000146] In some embodiments, the amount of IR absorbent in one or more layers is, based on the total weight of the layers, at least about 0.005 weight percent, at least about 0.0075 weight percent, at least about 0.01 weight percent, at least about 0.0125 weight percent, at least about 0.015 weight percent, at least about 0.0175 weight percent, at least about 0.020 weight percent, at least about 0.025 weight percent, at least about 0.030 weight percent, at least about 0.035 weight percent, at least about 0.040 weight percent, at least about 0.045 weight percent, and at least about 0.050 weight percent. Weight percent, at least about 0.055 weight percent, and / or about 0.090 weight percent or less, about 0.080 weight percent or less, about 0.075 weight percent or less, about 0.070 weight percent or less, about 0.065 weight percent or less, about 0.060 weight percent or less, about 0.055 weight percent or less, about 0.050 weight percent or less, about 0.045 weight percent or less, about 0.040 weight percent or less, about 0.035 weight percent or less, about 0.030 weight percent or less, about 0.025 weight percent or less, about 0.020 weight percent or less, about 0.015 weight percent or less, about 0.010 weight percent or less.

[0122] [000147] In some embodiments, the IR absorber may be substantially absent in one or more layers, for example, such that the amount of IR absorber in the layers is less than about 0.010 weight percent, less than about 0.005 weight percent, less than about 0.001 weight percent, or less than about 0.0005 weight percent, based on the total weight of the interlayer. In some embodiments, the IR absorber may be present in the above range of amounts in one or both of the outer skin layers and substantially absent in the inner core layer. In some embodiments, the IR absorber may be substantially absent in one or both of the outer skin layers and present in the inner core layer. In some embodiments, the IR absorber may be present in all layers of the interlayer.

[0123] [000148] When present in two or more layers of the interlayer, the amount of IR absorbent may be substantially the same in each layer or may differ between layers. For example, in some embodiments, the absolute difference in the amount of IR absorbent in two polymer layers may be at least about 0.005 percent, at least about 0.010 percent, at least about 0.015 percent, at least about 0.020 percent, and / or about 0.035 percent or less, about 0.030 percent or less, about 0.025 percent or less, about 0.020 percent or less, about 0.015 percent or less, about 0.010 percent or less, and about 0.005 percent or less. In some embodiments, the amount of IR absorbent may be substantially the same such that the absolute difference in the amount of IR absorbent in two or more layers present with IR absorbent is within about 0.0010 percent, about 0.005 percent, about 0.003 percent or less, about 0.002 percent or less, or about 0.001 percent or less.

[0124] [000149] In some embodiments, the IR absorber may be present in a generally constant amount or concentration from the top to the bottom of the interlayer (or from the thinnest edge to the thickest edge of the tapered region). That is, the absolute difference in the concentration of the IR absorber at one end of the interlayer (or the thinnest edge of the tapered region) and the other end (or the thickest edge of the tapered region) may be less than about 0.0001 weight percent, less than about 0.00005 weight percent, or less than about 0.00001 weight percent. In other embodiments, the absolute difference in the concentration of the IR absorber at one end of the interlayer (or the thinnest edge of the tapered region) and the other end (or the thickest edge of the tapered region) may be at least about 0.001 weight percent, at least about 0.005 weight percent, at least about 0.010 weight percent, or at least about 0.025 weight percent, and / or about 0.5 weight percent or less, about 0.4 weight percent or less, about 0.3 weight percent or less, about 0.25 weight percent or less, or about 0.10 weight percent or less. This can result in each layer being formed from the same resin (including the concentration of the IR absorber) at the thinnest and thickest parts of the tapered region (or layer or interlayer).

[0125] [000150] Any suitable type of IR absorber (IR absorbing agent) can be used. In some embodiments, the IR absorber may include an organic compound selected from the group consisting of phthalocyanines, naphthalocyanines, anthracianines, derivatives thereof, and combinations thereof. In some embodiments, the IR absorber may include a metal, such as copper, zinc, vanadium, or a combination thereof. In some embodiments, the IR absorber may include quaterrylene imide. Alternatively, one or more IR absorbers described in U.S. Patent No. 6,737,159 (incorporated herein by reference to the extent not inconsistent with this disclosure) may be included alone or in addition to any of the IR absorbers described herein.

[0126] [000151]The IR absorber can be in any suitable form, for example, in the form of particles. When present in the form of particles, the IR absorber can have a particle size of at least 5 nanometers, at least about 10 nanometers, at least about 15 nanometers, at least about 20 nanometers, at least about 25 nanometers, at least about 30 nanometers (nm), and / or about 100 nm or less, about 90 nm or less, about 80 nm or less, about 70 nm or less, about 60 nm or less, about 50 nm or less, about 40 nm or less, or about 35 nm or less. In some embodiments, the IR absorber can include metal oxide particles. Examples of suitable metal oxide particles include aluminum-doped tin oxide, indium-doped tin oxide, antimony-doped tin oxide (ATO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), aluminum-doped zinc oxide (AZO), niobium-doped titanium oxide, sodium-doped tungsten oxide, cesium-doped tungsten oxide, thallium-doped tungsten oxide, rubidium-doped tungsten oxide, tin-doped indium oxide (ITO), tin-doped zinc oxide particles, and silicon-doped zinc oxide, lanthanum hexaboride (LaB6), and metal oxide particles selected from the group consisting of combinations thereof, but are not limited thereto.

[0127] [000152]In some embodiments, the IR absorber particles can include tungsten oxide particles represented by one of the following formulas. W y O z [000153]Where W is tungsten, O is oxygen, and 2.0 < z / y < 3.0, 2.2 ≤ z / y ≤ 2.99, or 2.45 ≤ z / y ≤ 2.99 is satisfied, and / or M x W y O z [000154] In formula [000154], M is an element selected from H, He, alkali metals, alkaline earth metals, rare earth metals, Mg, Zr, Cr, Mn, Fe, Rh, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, and two or more combinations thereof, W is tungsten, O is oxygen, and satisfies 0.001≦x / y≦1.0 or 0.01≦x / y≦0.5, and 2.0≦z / y≦3.0, 2.2≦z / y≦2.99 or 2.45≦z / y≦2.99. Examples of tungsten / oxygen ratios include, but are not limited to, WO 2.92 WO 2.90 , W 20 O 58 , W 24 O 68 , W 17 O 47 , W 18 O 49 These include, etc. In a preferred embodiment, the tungsten oxide agent is cesium tungsten oxide (Cs) having any of the characteristics described above. 0.33 WO3) and in various embodiments, Cs 0.33 Cesium tungsten oxide having a molar ratio of WO3 is used. In some embodiments, the IR-absorbing particles may include cesium-doped tungsten oxide, cesium, tin-doped tungsten oxide, and combinations thereof.

[0128] [000155] In some embodiments, one or both of the outer skin layers may include a gradient color band near one or both of the edges of the interlayer. Such a gradient color band may be embedded in all or part of the outer skin layer of the interlayer and may have a thickness of at least 0.025 mm, at least about 0.05 mm, at least about 0.075 mm, at least about 0.10 mm, at least about 0.125 mm, at least about 0.15 mm, at least about 0.175 mm, at least about 0.20 mm, or at least about 0.225 mm, and / or about 0.375 mm or less, about 0.35 mm or less, about 0.325 mm or less, about 0.30 mm or less, about 0.275 mm or less, or about 0.25 mm or less. The outer skin layer resin may be present on one or both sides of the interlayer with a thickness of at least about 0.0125 mm, at least about 0.02 mm, at least about 0.025 mm, at least about 0.03 mm, or at least about 0.04 mm, and / or about 0.075 mm or less, about 0.06 mm or less, about 0.05 mm or less, about 0.04 mm or less, or about 0.035 mm or less. As used herein, the term “outer skin layer” includes, if present, a gradient color band.

[0129] [000156] According to some embodiments, at least one surface of the layer or interlayer may be textured to facilitate the formation of an interlayer or glazing. For example, at least a portion of the surface of one or more layers or at least one of the interlayers may have a surface roughness (Rz) of at least about 20 micrometers (microns), at least about 25 micrometers (microns), at least about 30 micrometers (microns), at least about 35 micrometers (microns), at least about 40 micrometers (microns), at least about 45 micrometers (microns), or at least about 50 micrometers (microns), and / or about 150 micrometers (microns) or less, about 140 micrometers (microns) or less, about 130 micrometers (microns) or less, about 120 micrometers (microns) or less, about 110 micrometers (microns) or less, about 100 micrometers (microns) or less, about 90 micrometers (microns) or less, about 80 micrometers (microns) or less, about 70 micrometers (microns) or less, about 60 micrometers (microns) or less, or about 40 micrometers (microns) or less.

[0130] [000157] As used herein, Rz is a measured value of the surface topography of a polymer layer, indicating the difference of the surface from a plane. Additionally, the surface roughness of a layer may be described by Rsm, where Rsm is a measured value of the distance between peaks in the surface topography of a polymer layer. Further descriptions of methods for determining Rz and Rsm are provided in U.S. Patent No. 7,883,761, which in whole is incorporated herein by reference to the extent that it is not inconsistent with this disclosure.

[0131] [000158] The Rsm of at least a portion of the surface of one or more layers of the interlayer film is at least about 300 micrometers (microns), at least about 325 micrometers (microns), at least about 350 micrometers (microns), at least about 375 micrometers (microns), at least about 400 micrometers (microns), at least about 425 micrometers (microns), at least about 450 micrometers (microns), at least about 475 micrometers (microns), at least about 500 micrometers (microns), at least about 525 micrometers (microns), at least about 550 micrometers (microns), at least about 575 micrometers (microns), and at least about 60 It may be 0 micrometers (microns), at least about 625 micrometers (microns), at least about 650 micrometers (microns), at least about 675 micrometers (microns), at least about 700 micrometers (microns), at least about 725 micrometers (microns), at least about 750 micrometers (microns), at least about 775 micrometers (microns), at least about 800 micrometers (microns), at least about 825 micrometers (microns), at least about 850 micrometers (microns), at least about 875 micrometers (microns), at least about 900 micrometers (microns), or at least about 925 micrometers (microns). Alternatively or additionally, the Rsm of at least a portion of the surface of one or more layers of the interlayer may be about 1000 micrometers (microns) or less, about 950 micrometers (microns) or less, about 900 micrometers (microns) or less, about 850 micrometers (microns) or less, about 800 micrometers (microns) or less, about 750 micrometers (microns) or less, about 700 micrometers (microns) or less, about 650 micrometers (microns) or less, about 600 micrometers (microns) or less, about 550 micrometers (microns) or less, or about 500 micrometers (microns) or less.

[0132] [000159] In some embodiments, if both two or more surfaces of a single layer, or two or more surfaces of different layers, are surface modified, the surfaces may have different roughness values. For example, in some cases, one surface may have an Rz that is at least about 5 percent, at least about 10 percent, at least about 15 percent, at least about 20 percent, at least about 25 percent, at least about 30 percent, at least about 35 percent, at least about 40 percent, at least about 45 percent, or at least about 50 percent different (i.e., higher or lower) than the Rz of the other surface. In some cases, this could be a difference of at least about 5 micrometers, at least about 10 micrometers, at least about 15 micrometers, at least about 20 micrometers, at least about 25 micrometers, at least about 30 micrometers, or at least about 35 micrometers, and / or less than or equal to about 100 micrometers, less than or equal to about 75 micrometers, less than or equal to about 60 micrometers, less than or equal to about 50 micrometers, less than or equal to about 40 micrometers, less than or equal to about 35 micrometers, less than or equal to about 30 micrometers, less than or equal to about 25 micrometers, or less than or equal to about 20 micrometers.

[0133] [000160] Such roughness can be achieved by any suitable method, including but not limited to embossing, melt fracturing, and combinations thereof. A method for determining surface roughness is described in U.S. Patent No. 7,883,761, which is incorporated herein by reference to the extent that it is not inconsistent with the present disclosure.

[0134] [000161] The interlayers described herein may be formed by any suitable method. In some embodiments, a method for producing a multilayer interlayer may include the step of preparing a first type of resin and a second type of resin. The first type of resin may be used, for example, to form a skin layer and may be considered a “skin” resin, while the second type of resin may be used to form a core layer and may be considered a “core” resin. As discussed above, the skin resin and the core resin may include, for example, a poly(vinyl butyral) resin and a plasticizer and may have different compositions from each other.

[0135] [000162] To form the interlayer described herein, the skin resin may be divided into two or more parts, with one part used to form one outer skin layer and the other part used to form the other outer skin layer. In some cases, the first and second parts of the skin resin may be supplied to the die at different mass flow rates to form outer skin layers having different thicknesses. In some embodiments, the mass flow rate of the resin used to form one (thin) skin layer may be at least about 10 percent, at least about 15 percent, at least about 20 percent, at least about 25 percent, at least about 30 percent, at least about 35 percent, at least about 40 percent, at least about 45 percent, at least about 50 percent, at least about 55 percent, at least about 60 percent, at least about 65 percent, at least about 70 percent, at least about 75 percent, or at least about 80 percent lower than the mass flow rate of the resin used to form the other (thick) skin layer.

[0136] [000163] In some embodiments, the mass flow rate of the resin used to form one skin layer may be about 95 percent or less, about 90 percent or less, about 85 percent or less, about 80 percent or less, about 75 percent or less, about 70 percent or less, about 65 percent or less, about 60 percent or less, about 55 percent or less, about 50 percent or less, about 45 percent or less, about 40 percent or less, about 35 percent or less, about 30 percent or less, or about 25 percent or less of the mass flow rate of the resin used to form the other skin layer.

[0137] [000164] In some cases, different mass flow rates used to form the outer skin layer can be provided by one or more of several techniques. For example, in some embodiments, the skin resin may be divided into two flows, each of which may be controlled to have different mass flow rates. As a result, the thickness of each layer may be different, thereby providing an interfilm having the skin layer described herein.

[0138] [000165] Several methods exist for controlling the mass flow rate of the skin resin portion. In some cases, the mass flow rate of the skin resin can be controlled by using separate pumps to individually control the mass flow rate of the resin used to form each outer layer. In some embodiments, different mass flow rates of the resin can be achieved using separate extruders to form the outer skin layers individually, and then the outer skin layers can be laminated (along the core layer) to form a multilayer interlayer.

[0139] [000166] When forming an interlayer, the skin layer resin may be divided into two or more parts, at least one of which will be used to form the outer skin layer. Before forming the layer, the skin resin flow may be divided into two parts by the use of a splitter, and the separate flows may be formed into a sheet or layer using a die. A first flow path of the first part of the resin molten or flow may be defined between the splitter and the die, and a second flow path may be defined between the splitter and the die, and in some cases a flow restrictor may be present along the second flow path, so that the mass flow rate of one of the flows (passing through or over the flow restrictor) is less than the mass flow rate of the flow in the first flow path. In some embodiments, the flow restrictor may have a minimum opening area of ​​about 95 percent or less, about 90 percent or less, about 85 percent or less, about 80 percent or less, about 75 percent or less, about 70 percent or less, about 65 percent or less, about 60 percent or less, about 55 percent or less, or about 50 percent or less of the minimum opening area along the first flow path.

[0140] [000167] In some embodiments, different mass flow rates of resin can be achieved by using melt pipes having different average cross-sectional areas that transport the resin to the die to form the respective outer skin layers. That is, the diameter of at least a portion of the pipe used to form all or part of the first flow path may be smaller than the diameter of at least a portion of the pipe used to form all or part of the second flow path. In some cases, the minimum diameter of the pipe in the second flow path may be at least about 5 percent, at least about 10 percent, at least about 15 percent, at least about 20 percent, at least about 25 percent, at least about 30 percent, or at least about 35 percent smaller than the minimum diameter of the pipe in the first flow path.

[0141] [000168] When forming the interlayer described herein, in some cases each of the above may be used, while in other cases only one of the above methods or a combination of two or more may be used.

[0142] [000169] In some embodiments, the formation of the outer skin layer may be carried out using a die having a first skin exit for forming a first outer skin layer and a second skin exit for forming a second outer skin layer. The first and second skin exits may have thicknesses substantially corresponding along the widths of the first and second skin exits. In some cases, such exits may be geometrically identical, and / or one or both of the first and second skin exits may be wedge-shaped.

[0143] [000170] In some embodiments, the multilayer interlayer may be formed by co-extrusion. In such a method, at least three resin flows, including a first outer skin resin flow, a second outer skin resin flow, and an inner core resin flow positioned between the first and second outer skin resin flows, may be extruded simultaneously from the die to form a co-extruded resin sheet.

[0144] [000171] If at least a portion of the interlayer is formed by co-extrusion, the co-extruded layer may be formed using a multi-manifold die having at least two outlets configured to form layers of different thicknesses and / or shapes. The flow of resin, including the skin resin, to the different outlets may be different to form the skin layer of the final interlayer as described herein.

[0145] [000172] In other cases, at least a portion of the co-extruded material may be formed using a single manifold die, and the flow of skin resin may be divided by a die feed block having one or more dividing elements. The resulting flow of skin resin may then be regulated as described above to provide an interfilm having the skin layer described herein.

[0146] [000173] In some embodiments, the multilayer interlayer may be formed by separately extruding a first outer skin flow, a second outer skin flow, and a core layer resin flow to form three separate layers, and then stacking the layers together to form the multilayer interlayer.

[0147] [000174] In some embodiments, both co-extrusion and lamination may be used to form a multilayer intermediate. In some cases, co-extrusion may be used to form a multilayer sheet having, for example, at least two, at least three, or four or more layers. The sheet may then be laminated onto another sheet having one or more other layers to form a multilayer intermediate. In some cases, one or more layers of the sheet may be flat, while one or more layers of the sheet may be wedge-shaped. In some embodiments, the multilayer sheet may have a flat profile and may be laminated onto a single-layer sheet having a wedge-shaped profile to provide a wedge-shaped multilayer interfilm.

[0148] [000175] Interlayers constructed and formed according to embodiments of the present invention may exhibit enhanced optical and / or acoustic properties compared to interlayers formed from conventional polymer layers. For example, in some embodiments, the interlayer may have a mottle value of about 3.5 or less, about 3.25 or less, about 3 or less, about 2.75 or less, about 2.5 or less, about 2.25 or less, about 2 or less, about 1.75 or less, about 1.5 or less, or about 1 or less. Mottle is a measure of optical properties and is described as texture or granularity. Too much or too much mottle results in an unsightly visual appearance of the interlayer or glazing.

[0149] [000176] Spotting is evaluated and classified by parallel quantitative comparison with shadow graph projections of test laminates having a set of standard laminate shadow graphs, where 1 represents the standard for low spotting (i.e., a low number of disturbances) and 4 represents the standard for high spotting (i.e., a high number of disturbances). High spotting is generally considered visually unsightly in automotive and building applications. Optionally, a laminate model with a single-layer interlayer of zero spotting (no spotting) is used to facilitate the evaluation of test laminates with spotting ranks lower than the standard set, e.g., lower than rank 1. Test laminates exhibiting shadow graph projections similar to zero spotting laminates are assessed as having a spotting rank of zero. Test laminates are prepared from two transparent glass sheets (commercially available from Pittsburgh Glass Works of Pennsylvania) and an interlayer, each 2.3 mm thick. The interlayer typically has a random roughness of approximately 35–40 micrometers (microns) R z It has a thickness of 0.76 to 0.86 mm.

[0150] [000177] The spot values ​​presented herein were determined using a Clear Mottle Analyzer (CMA) comprising a xenon arc lamp, a sample holder, a projection screen, and a digital camera. The xenon arc lamp is used to project a shadow graph of the stacked sample onto the screen, and the camera is configured to acquire an image of the resulting shadow graph. The image is then digitally analyzed using computer imaging software and compared with previously acquired images of standard samples to determine the spotting of the sample. A method for measuring spotting using a CMA is described in detail in U.S. Patent No. 9,311,699.

[0151] [000178] In some cases, the mottling of an interlayer having outer skin layers of different thicknesses as described herein may be at least about 5 percent, at least about 10 percent, at least about 15 percent, at least about 20 percent, at least about 25 percent, at least about 30 percent, at least about 35 percent, at least about 40 percent, at least about 45 percent, at least about 50 percent, at least about 55 percent, at least about 60 percent, at least about 65 percent, at least about 70 percent, at least about 75 percent, at least about 80 percent, at least about 85 percent, at least about 90 percent, or at least about 95 percent lower than the mottling of the same interlayer having two outer skin layers of the same thickness, but having the same composition and structure.

[0152] [000179] Transparency is another optical parameter used to describe the performance of the interlayers described herein and may be determined by measuring the haze value or percentage. The haze value represents a quantification of the light scattered by the sample with respect to incident light. In some embodiments, the resin blends, layers and interlayers described herein may have haze values ​​of less than 5 percent, less than about 4 percent, less than about 3 percent, less than about 2 percent, less than about 1 percent, or less than about 0.5 percent when measured according to ASTM D1003-13-Procedure B using Illuminance C at an observation angle of 2 degrees. The test is performed using a spectrophotometer, e.g., a Hunterlab UltraScan XE instrument (commercially available from Hunter Associates, Reston, Va.) on a polymer sample having a thickness of 0.76 mm laminated between two transparent glass sheets (commercially available from Pittsburgh Glass Works of Pennsylvania) each having a thickness of 2.3 mm.

[0153] [000180] In some embodiments, the interlayers described herein may have a visible transmittance percentage (Tvis%), which is measured using a spectrophotometer, e.g., Hunterlab UltraScan EX, according to ASTM D1003, Procedure B, using Illuminance C at an observation angle of 2°. The values ​​presented herein were obtained by analyzing glass laminate samples (commercially available from Pittsburgh Glass Works of Pennsylvania) having an interlayer thickness of about 0.76 mm and a clear glass thickness of 2.3 mm. In some embodiments, the polymer layers and interlayers of the present invention may have a visible transmittance percentage of at least about 65 percent, at least about 70 percent, at least about 75 percent, at least about 80 percent, at least about 81 percent, at least about 82 percent, at least about 83 percent, at least about 84 percent, at least about 85 percent, at least about 85.5 percent, at least about 86 percent, at least about 86.5 percent, at least about 87 percent, at least about 87.5 percent, at least about 88 percent, or at least about 88.5 percent. These values ​​may refer to the overall or average transmittance of the entire interlayer.

[0154] [000181] In some embodiments, the interlayer may have visible properties that do not change much between the thinnest and thickest edges of the tapered region. For example, the interlayer may have a visible transmittance (%Tvis) at the thickest edge which is within about 30 percent, 25 percent, 20 percent, 15 percent, 10 percent, 5 percent, 4.5 percent, 4 percent, 3.5 percent, 3 percent, 2.5 percent, 2 percent, 1.5 percent, 1 percent, 0.75 percent, 0.65 percent, 0.60 percent, 0.55 percent, 0.50 percent, 0.45 percent, and 0.40 percent of the visible transmittance (%Tvis) at the thinnest edge of the tapered region. The visible transmittance at the thinnest edge and / or the thickest edge of the tapered region may be at least about 65 percent, at least about 70 percent, at least about 75 percent, at least about 80 percent, at least about 81 percent, at least about 82 percent, at least about 83 percent, at least about 84 percent, at least about 85 percent, at least about 85.5 percent, at least about 86 percent, at least about 86.5 percent, at least about 87 percent, at least about 87.5 percent, at least about 88 percent, or at least about 88.5 percent.

[0155] [000182] In some embodiments, the interlayer may have a total solar transmittance (%Tts) of about 75% or less, about 70% or less, about 65% or less, about 60% or less, about 55% or less, about 50% or less, or about 45% or less, as measured according to ISO 13837. Furthermore, even if the thickness profile of one or more layers and the interlayer as a whole changes, the total solar transmittance may not change substantially across the tapered region. In some embodiments, the interlayer is approximately 30%, 25%, 20%, 15%, 10%, 5%, 4.5%, 4%, 3.5%, 3%, 2.5%, 2%, 1.5%, 1.5%, 1%, 0.75%, 0.70%, 0.65%, 0.60%, and 0.55% of the total solar transmittance (%Tts) at the thinnest edge of the tapered region. The total solar transmittance (300nm~2500nm) (%Tts) at the thickest edge of the tapered region may be within, approximately 0.50%, approximately 0.45%, approximately 0.40%, approximately 0.35%, approximately 0.30%, approximately 0.25%, approximately 0.20%, approximately 0.15%, approximately 0.10%, approximately 0.05%, approximately 0.01%, approximately 0.005%, approximately 0.001%, or approximately 0%. The total solar transmittance at the thinnest and / or thickest edges of the tapered region may be approximately 75% or less, approximately 70% or less, approximately 65% ​​or less, approximately 60% or less, approximately 55% or less, approximately 50% or less, approximately 55% or less, or approximately 45% or less, when measured as described above.

[0156] [000183] The interlayers described herein can also exhibit desirable acoustic performance. For example, in some embodiments, the interlayers according to embodiments of the present invention can have a tandelta value of at least about 0.70. Tandelta is the ratio of the loss modulus (G") in Pascal units to the storage modulus (G') in Pascal units of a specimen, measured by dynamic mechanical thermal analysis (DMTA). DMTA is performed at an oscillation frequency of 1 Hz in shear mode and a temperature sweep rate of 3 °C / min. The peak value of the G'' / G' curve at the glass transition temperature is the tandelta value. The tandelta of the interlayer described herein may be at least about 1.0, at least about 1.05, at least about 1.10, at least about 1.25, at least about 1.50, at least about 1.75, at least about 2.0, or at least about 2.25, and / or about 5 or less, about 4.75 or less, about 4.5 or less, about 4.25 or less, about 4 or less, about 3.75 or less, about 3.5 or less, about 3.25 or less, about 3 or less, or about 2.5 or less.

[0157] [000184] Furthermore, the interlayer may have a damping loss coefficient or loss coefficient of at least about 0.10, at least about 0.15, at least about 0.17, at least about 0.20, at least about 0.25, at least about 0.27, at least about 0.30, at least about 0.33, or at least about 0.35. The loss coefficient is measured by mechanical impedance measurement as described in ISO standard 16940. A polymer sample is laminated between two transparent glass sheets, each 2.3 mm thick, to a width of 25 mm and a length of 300 mm. The laminated sample is then excited at its center point using a vibration shaker commercially available from Bruel and Kjaer (Naerum, Netherlands), and the force and vibration velocity required to excite and vibrate the bar are measured using an impedance head (Bruel and Kjaer). The resulting transfer function is recorded in a National Instrument data acquisition and analysis system, and the loss coefficient in the first vibration mode is calculated using the half-power method.

[0158] [000185] Glazing can be formed using the interlayers described herein. The glazing (or laminate or panel) can be formed by sandwiching the interlayers according to embodiments of the present invention between first and second rigid substrates and laminating the structures to form a multilayer glazing. In some embodiments, the glazing may refer to an interlayer sandwiched between a rigid substrate and a polymer film, such as a bilayer.

[0159] [000186] The multilayer glazing or panel described herein generally comprises a first rigid substrate sheet having the thickness of a first substrate and a second rigid substrate sheet having the thickness of a second substrate. Each of the first and second substrates may be formed from a rigid material such as glass, and may be formed from the same or different materials. In some embodiments, at least one of the first and second substrates may be a glass substrate, while in other embodiments, at least one of the first and second may be made from another material, including rigid polymers such as polycarbonate, copolyester, acrylic resin, polyethylene terephthalate, and combinations thereof. In embodiments, both rigid substrates are glass. Depending on the required performance and properties, any suitable type of non-glass material may be used to form such substrates. Typically, neither rigid substrate is formed from a softer polymer material, including the thermoplastic polymer materials described in detail below.

[0160] [000187] A rigid glass substrate can be formed using any suitable type of glass, and in some embodiments, the glass can be selected from the group consisting of aluminosilicate glass, borosilicate glass, quartz or fused silica glass, and soda-lime glass. The glass substrate, if used, can be strengthened by annealing, thermal strengthening or strengthening, chemical strengthening, etching, coating, or ion exchange, or one or more of these treatments may be applied. The glass itself may be roll-formed glass, float glass, or plate glass. In some embodiments, the glass may not be chemically treated or strengthened by ion exchange, and in other embodiments, the glass may not be aluminosilicate glass. If the first and second substrates are glass substrates, the types of glass used to form each substrate may be the same or different.

[0161] [000188] The rigid substrate can have any suitable thickness. In some embodiments, when the rigid substrate is all glass substrate, the nominal thickness of at least one of the glass sheets (first or second glass) is in the range of 0.1 mm to 12.7 mm, and the multilayer glass panel includes configurations of any combination of the first and second glass sheets (and any other glass or rigid sheet as needed). In some embodiments, the nominal thickness of the first and / or second substrate may be at least about 0.4 mm, at least about 0.5 mm, at least about 0.7 mm, at least about 0.75 mm, at least about 1.0 mm, at least about 1.25 mm, at least about 1.3 mm, at least about 1.6 mm, at least about 1.9 mm, at least about 2.2 mm, at least about 2.5 mm, or at least about 2.8 mm, and / or less than about 3.2 mm, less than about 2.9 mm, less than about 2.6 mm, less than about 2.5 mm, less than about 2.3 mm, less than about 2.0 mm, less than about 1.75 mm, less than about 1.7 mm, less than about 1.5 mm, less than about 1.4 mm, or less than about 1.1 mm.

[0162] [000189] Additionally or alternatively, the first and / or second substrates may have nominal thicknesses of at least about 2.3 mm, at least about 2.6 mm, at least about 2.9 mm, at least about 3.2 mm, at least about 3.5 mm, at least about 3.8 mm, or at least about 4.1 mm, and / or less than about 12.7 mm, less than about 12.0 mm, less than about 11.5 mm, less than about 10.5 mm, less than about 10.0 mm, less than about 9.5 mm, less than about 9.0 mm, less than about 8.5 mm, less than about 8.0 mm, less than about 7.5 mm, less than about 7.0 mm, less than about 6.5 mm, less than about 6.0 mm, less than about 5.5 mm, less than about 5.0 mm, or less than about 4.5 mm. Other thicknesses may be appropriate depending on the application and required properties.

[0163] [000190] When a multilayer panel includes two substrates of the same nominal thickness, the ratio of the nominal thickness of one substrate to the nominal thickness of the other substrate is equal to 1, and such a panel may be called a “symmetrical configuration.” When a multilayer panel includes two substrates having different nominal thicknesses, the ratio of the nominal thickness of one substrate to the nominal thickness of the other substrate is not equal to 1, and such a panel may be called an “asymmetrical configuration.” As used herein, an asymmetrical configuration or asymmetrical panel is characterized by a ratio of substrate thicknesses (of the thinner substrate to the thicker substrate) being less than 1, and a symmetrical configuration or symmetrical panel is characterized by a ratio of substrate thicknesses being equal to 1 (i.e., the substrates are the same thickness).

[0164] [000191] In some embodiments, the multilayer panel may include two substrates having the same nominal thickness. In other embodiments, the multilayer panel may include two substrates having different nominal thicknesses. As used herein, the terms “substrate symmetry” and “glass symmetry” refer to the ratio of the nominal thickness of the first or thinner substrate (or glass sheet) to the nominal thickness of the second or thicker substrate (or glass sheet), and these terms are used interchangeably. “Glass symmetry” is determined by formula (VI). Symmetry of glass (S G ) = H3 / H1(2), In the formula, H3 is the nominal thickness of the thinner (first) glass substrate, H1 is the nominal thickness of the thicker (second) glass substrate, and H3 ≤ H1.

[0165] [000192] When used herein to refer to a multilayer glass panel, the term “symmetrically configured” means that the symmetry of the glass is equal to 1 S G The term "asymmetrically constructed" means having a glass symmetry of less than 1. The terms "glass symmetry," "symmetrically constructed," "symmetrical construction," and "symmetry of glass construction" are interchangeable throughout. The terms "asymmetrically constructed" and "asymmetrical construction" are interchangeable throughout.

[0166] [000193] In some embodiments, the multilayer panels or glazing described herein are at least about 0.10, at least about 0.15, at least about 0.20, at least about 0.23, at least about 0.25, at least about 0.30, at least about 0.35, at least about 0.40, at least about 0.45, at least about 0.50, at least about 0.55, at least about 0.60, at The glass may have a symmetry of about 0.65, at least about 0.70, at least about 0.75, and / or about 1, about 0.99 or less, about 0.97 or less, about 0.95 or less, about 0.90 or less, about 0.85 or less, about 0.80 or less, about 0.75 or less, about 0.70 or less, about 0.65 or less, about 0.60 or less, about 0.55 or less, about 0.50 or less, about 0.45 or less, about 0.40 or less, about 0.35 or less, and about 0.30 or less. In some embodiments, the multilayer panels described herein may be symmetrical and have a glass symmetry of 1.

[0167] [000194] When the multilayer panel has an asymmetrical configuration, the difference between the nominal thickness of the thicker substrate and the nominal thickness of the thinner substrate may be at least about 0.05 mm. In some embodiments, at least one glass sheet may have a nominal thickness that is at least about 0.1 mm, at least about 0.2 mm, at least about 0.3 mm, at least about 0.4 mm, at least about 0.5 mm, at least about 0.6 mm, at least about 0.7 mm, at least about 0.8 mm, at least about 0.9 mm, at least about 1.0 mm, at least about 1.2 mm, at least about 1.6 mm, at least about 2.0 mm, at least about 3.0 mm, or at least about 4.0 mm thicker than at least one of the other glass sheets or each of the other glass sheets.

[0168] [000195] In some embodiments, one layer of glass (or rigid substrate) may be at least about 1.05 times, at least about 1.1 times, at least about 1.2 times, at least about 1.3 times, at least about 1.4 times, at least about 1.5 times, at least about 1.6 times, at least about 1.7 times, at least about 1.8 times, at least about 1.9 times, or 2.0 times thicker than the other layer of glass (or rigid substrate), and / or may be about 10 times or less, about 8 times or less, about 6 times or less, about 5 times or less, about 4 times or less, about 3.5 times or less, about 3 times or less, about 2.5 times or less, about 2 times or less, or about 1.5 times or less thicker than the other layer of glass (or rigid substrate).

[0169] [000196] In some embodiments, one or both of the substrates can be wedge-shaped. When one or both of the rigid substrates are wedge-shaped substrates, the substrates can be defined with a wedge angle of at least about 0.05 milliradians, at least about 0.10 milliradians, at least about 0.15 milliradians, at least about 0.20 milliradians, at least about 0.25 milliradians, at least about 0.30 milliradians, or at least about 0.35 milliradians, and / or less about 1 milliradian, less about 0.95 milliradians, less about 0.90 milliradians, less about 0.85 milliradians, less about 0.80 milliradians, less about 0.75 milliradians, less about 0.70 milliradians, less about 0.65 milliradians, less about 0.60 milliradians, or less about 0.55 milliradians. If both substrates are wedge-shaped, the substrates may have substantially similar wedge angles to each other, within approximately 0.001 milliradians, within approximately 0.005 milliradians, or within approximately 0.01 milliradians.

[0170] [000197] Alternatively, when both are wedge-shaped, one of the wedge-shaped substrates may have a different wedge angle than the other. For example, in some embodiments, one of the substrates may have a smaller wedge angle than the other substrate. In some embodiments, the difference between the wedge angles of the two wedge-shaped substrates may be at least about 0.05 milliradians, at least about 0.075 milliradians, at least about 0.10 milliradians, or at least about 0.12 milliradians, and / or about 0.50 milliradians or less, about 0.45 milliradians or less, about 0.40 milliradians or less, about 0.35 milliradians or less, about 0.30 milliradians or less, about 0.25 milliradians or less, about 0.20 milliradians or less, or about 0.15 milliradians or less. In some embodiments, one or both of the rigid substrates may each have a uniform thickness (for example, they may not be wedge-shaped, i.e., they may be essentially flat).

[0171] [000198] Examples of suitable types of multilayer panels include windows for automotive applications, including but not limited to windshields, side windows, and sunroofs. Examples of suitable types of multilayer panels for architectural applications include, but not limited to, windows, as well as laminated glass panels for doors, walls, ceilings, and passageways.

[0172] [000199] In some embodiments, for example, as schematically shown in Figure 7, the windshield 20 formed as described herein may have a thinner lower edge 14 and a thicker upper edge 12. In some cases, the lower edge 14 may have a total thickness of at least about 1.5 mm, at least about 2 mm, at least about 2.5 mm, at least about 3 mm, or at least about 3.25 mm, and / or about 10 mm or less, about 8 mm or less, about 6 mm or less, about 5 mm or less, or about 4 mm or less. The thickness of the thicker (upper) edge 12 may be at least about 1.1 times, at least about 1.25 times, at least about 1.5 times, at least about 1.75 times, at least about 2.0 times, at least about 2.25 times, or at least about 2.5 times thicker than the thickness of the thinner (lower) edge. In some cases, the maximum thickness of the interlayer at or near the thinnest (lower) edge 14 of the windshield is within approximately 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, or 85 mm from the thinnest edge 14, and not exceeding 0.3 mm, 0.29 mm, 0.28 mm, 0.27 mm, 0.26 mm, 0.25 mm, or 0.24 mm.

[0173] [000200] In some embodiments, the windshield (or other panel) may have a wedge angle of at least about 0.05 milliradians, at least about 0.10 milliradians, at least about 0.15 milliradians, at least about 0.2 milliradians, or at least about 0.3 milliradians, and / or less than or equal to about 1 milliradian, less than or equal to about 0.90 milliradians, less than or equal to about 0.80 milliradians, less than or equal to about 0.75 milliradians, less than or equal to about 0.70 milliradians, or less than or equal to about 0.60 milliradians.

[0174] [000201]The following examples further illustrate how the polyester of the present invention can be manufactured and evaluated, and how polyurethane adhesives can be manufactured and evaluated, and are intended to be purely illustrative and not intended to limit the scope of the present invention. Unless otherwise specified, parts are parts by weight, temperature is in degrees Celsius or ambient temperature, and pressure is atmospheric pressure or near atmospheric pressure. [Examples]

[0175] [000202]Two different multilayer interlayers were formed from three layers of poly(vinyl butyral) plasticized with triethylene glycol di-2-ethylhexanoate. The first interlayer, comparative interlayer 1 (CIL-1), included two outer skin layers, indicated as skin 1 and skin 2 in Figure 10, and an inner core layer, indicated as the core layer in Figure 10. As shown in Figure 10, the nominal thicknesses of skin 1 and skin 2 of CIL-1 were approximately the same, and the nominal thickness of the core layer of CIL-1 was smaller than that of either skin layer. A second similar comparative interlayer was also formed and is referred to herein as comparative interlayer 2 (CIL-2). Table 1 below summarizes the compositions of the skin and core layers of CIL-1 and CIL-2.

[0176] [Table 1]

[0177] [000203] Another interlayer, Disclosed Interlayer 1 (DIL-1), was also formed from three layers of poly(vinyl butyral) having the same composition as the corresponding layer of CIL-1 summarized in Table 1 above. However, as shown in Figure 11, one outer skin layer (skin 2) of DIL-1 was thinner than the other outer skin layer (skin 1) of DIL-1. A second similar Disclosed Interlayer was also formed and is referred to herein as Disclosed Interlayer 2 (DIL-2).

[0178] [000204]The thicknesses of the skin layers 1 and 2, and the core layer of CIL-1 and 2, as well as DIL-1 and 2, are summarized in Table 2 below. In addition, the surface roughness (Rz and Rsm) of the skin layers of CIL-1 and 2, and DIL-1 and 2, were measured and are also shown in Table 2 below.

[0179] [Table 2]

[0180] [000205] As shown above, CIL-1 had a similar surface topography to both skin layers and exhibited relatively high mottling (3.7). In addition, CIL-2 had lower Rz and Rsm than CIL-1, but CIL-2 still exhibited very high mottling (3.9).

[0181] [000206] Disclosed interlayers 1 and 2 (DIL-1 and DIL-2) both contained an outer skin layer with a surface topography similar to CIL-2, but exhibited significantly reduced mottling (1.2 for DIL-1 and 2.0 for DIL-2). The present invention includes the following embodiments. [1] A first polymer layer having a wedge shape, A second polymer layer having a wedge shape, and A third polymer layer between the first layer and the second layer. Includes, The first and second layers each have a Tg at least 10°C higher than the glass transition temperature (Tg) of the third layer. A wedge-shaped multilayer interlayer, At one or more locations of the interlayer, the second layer is at least 10 percent thicker than the first layer. At least one of the first and second layers has a thickness of 0.3 mm or less at one or more locations of the interlayer film. Wedge-shaped multilayer interlayer film. [2] The interlayer according to [1], wherein the interlayer has a thinnest edge portion and a thickest edge portion, and the maximum thickness of at least one of the first and second outer layers does not exceed 0.3 mm within 40 centimeters from the thinnest edge portion. [3] The interlayer according to [1], wherein at one or more locations of the interlayer, the first layer has a thickness of less than 0.3 millimeters and the second layer has a thickness of more than 0.3 millimeters. [4] The interlayer according to [1], wherein at one or more locations of the interlayer, the first layer is at least 0.01 millimeters thinner than the second layer. [5] The interlayer according to [1], wherein the first layer is at least 10 percent thinner than the second layer over at least 25 percent of the total area of ​​the interlayer. [6] The interlayer according to [1], wherein the interlayer has a thinnest edge and a thickest edge on the opposite side, and the maximum thickness of at least one of the first and second layers does not exceed 0.3 mm within 10 centimeters from the thinnest edge. [7] The interlayer according to [1], wherein the interlayer has a thinnest edge and a thickest edge on the opposite side, the thinnest edge having a total thickness of at least 0.5 and / or 1.1 mm or less, and the thickest edge having a thickness of at least 0.6 mm and / or 2.0 mm or less. [8] The interlayer according to [1], wherein the interlayer includes a tapered region having a thinnest edge and a thickest edge, and the thickness of the first polymer layer at the thinnest edge of the tapered region is greater than the thickness of the first polymer layer at the thickest edge of the tapered region. [9] The interlayer film according to [1], wherein the ratio of the thickness of the first polymer layer to the thickness of the thinnest edge of the tapered region is at least 0.20:1 and / or 0.85 or less:1, and the ratio of the thickness of the second polymer layer to the thickness of the thinnest edge of the tapered region is at least 0.1:1 and / or 0.45 or less:1.

[10] The interlayer is a three-layer interlayer, the first, second and third layers are each formed from a plasticized polyvinyl acetal resin, the third polymer layer has a plasticizer content that is at least 5 phr (parts per 100 parts of resin) and / or 75 phr or less different from the plasticizer content of the first and / or second polymer layer, the third polymer layer has a glass transition temperature (Tg) that is at least 2°C and / or 50°C or less different from the glass transition temperature (Tg) of the first and / or second polymer layer, and the polyvinyl acetal contains polyvinyl butyral, and the The interfilm according to [1], wherein the polyvinyl butyral in the first and second layers has a residual acetate content of less than 15 weight percent, the maximum difference in the residual hydroxyl content of the polyvinyl butyral in the first or second and third polymer layers is at least 3 percent, at least a portion of the surface of the interfilm has a surface roughness (Rz) of 5 to 75 micrometers (microns), the interfilm has an overall wedge angle of at least 0.05 milliradians and 1 milliradian or less, and the interfilm has a spot value of 3.5 or less.

[11] A glazing formed from at least one rigid substrate and the interlayer described in [1].

[12] comprising first, second and third polymer layers, The third layer is located between the first layer and the second layer. The first and second layers each have a Tg at least 10°C higher than the glass transition temperature (Tg) of the third layer. It is a multilayer interlayer, At one or more locations of the interlayer, the first layer has a thickness of less than 0.3 millimeters, and the second layer has a thickness of more than 0.3 millimeters. Criteria (i) through (iii): (i) At one or more locations of the interlayer, the first layer has a thickness of at least 0.2 mm. (ii) At one or more locations of the interlayer, the ratio of the thickness of the second layer to the thickness of the first layer is 2.5 or less:1, and (iii) The maximum difference in polyvinyl acetate content between any two of the first, second, and third polymer layers is 13 weight percent or less. A multilayer interlayer that satisfies at least one of the following conditions.

[13] The interlayer according to

[12] , wherein at least one of the first, second, and third polymer layers is wedge-shaped.

[14] The interlayer according to

[12] , which satisfies at least two of the above criteria (i) to (iii).

[15] The interlayer according to

[12] , wherein the first layer is at least 0.01 millimeters thinner than the second layer over at least 25 percent of the total area of ​​the interlayer.

[16] The interlayer according to

[12] , wherein the first layer has a thickness of less than 0.3 millimeters and the second layer has a thickness of more than 0.3 millimeters over at least 10 percent of the total area of ​​the interlayer.

[17] The interlayer according to

[12] , wherein the interlayer has a thinnest edge and a thickest edge on the opposite side, and the maximum thickness of at least one of the first and second layers does not exceed 0.3 mm within 10 centimeters from the thinnest edge.

[18] The interlayer according to

[12] , having the same composition and shape as the comparative interlayer except that it has an outer skin layer of the same shape and thickness, and having a spot value at least 5 percent lower than the spot value of the comparative interlayer.

[19] The interlayer according to

[12] , wherein the tapered region constitutes approximately 90% or less of the entire vertical cross-section of the interlayer.

[20] The interlayer is a three-layer interlayer, the first, second and third layers are each formed from a plasticized polyvinyl acetal resin, the third polymer layer has a plasticizer content that is at least 5 phr (parts per 100 parts of resin) and / or 75 phr or less different from the plasticizer content of the first and / or second polymer layer, the third polymer layer has a glass transition temperature (Tg) that is at least 2°C and / or 50°C or less different from the glass transition temperature (Tg) of the first and / or second polymer layer, the polyvinyl acetal contains polyvinyl butyral, and the first The interfilm according to

[12] , wherein the polyvinyl butyral in the second layer has a residual acetate content of less than 15 weight percent, the maximum difference in the residual hydroxyl content of the polyvinyl butyral in the first or second and third polymer layers is at least 3 percent, at least a portion of the surface of the interfilm has a surface roughness (Rz) of 5 to 75 micrometers (microns), the interfilm has an overall wedge angle of at least 0.05 milliradians and 1 milliradian or less, and the interfilm has a spot value of 3.5 or less.

[21] A glazing formed from at least one rigid substrate and the interlayer described in

[12] .

[22] First wedge-shaped polymer outer layer, The second wedge-shaped polymer outer layer, and Polymer core layer sandwiched between the first outer layer and the second outer layer Includes, Each of the outer layers has a Tg that is at least 10°C higher than the glass transition temperature (Tg) of the core layer. A wedge-shaped multilayer interlayer, The interlayer has an overall wedge angle of at least 0.05 milliradians and 1 milliradian or less. The interlayer has a thinnest edge portion and a thickest edge portion, and the maximum thickness of at least one of the first and second outer layers does not exceed 0.3 mm within 40 centimeters from the thinnest edge portion. Wedge-shaped multilayer interlayer film.

[23] The interlayer according to

[22] , wherein at one or more locations of the interlayer, the first layer has a thickness of less than 0.3 millimeters and the second layer has a thickness of more than 0.3 millimeters.

[24] The interlayer according to

[22] , wherein the first layer is at least 10 percent thinner than the second layer over at least 25 percent of the total area of ​​the interlayer.

[25] The interlayer according to

[22] , wherein the interlayer has a thinnest edge and a thickest edge on the opposite side, and the maximum thickness of at least one of the first and second layers does not exceed 0.3 mm within 10 centimeters from the thinnest edge.

[26] The interlayer according to

[22] , wherein the tapered region constitutes approximately 90% or less of the entire vertical cross-section of the interlayer.

[27] The interlayer is a three-layer interlayer, the first, second and third layers are each formed from a plasticized polyvinyl acetal resin, the third polymer layer has a plasticizer content that is at least 5 phr (parts per 100 parts of resin) and / or 75 phr or less different from the plasticizer content of the first and / or second polymer layer, the third polymer layer has a glass transition temperature (Tg) that is at least 2°C and / or 50°C or less different from the glass transition temperature (Tg) of the first and / or second polymer layer, the polyvinyl acetal contains polyvinyl butyral, and the first The interfilm according to

[22] , wherein the polyvinyl butyral in the second layer has a residual acetate content of less than 15 weight percent, the maximum difference in the residual hydroxyl content of the polyvinyl butyral in the first or second and third polymer layers is at least 3 percent, at least a portion of the surface of the interfilm has a surface roughness (Rz) of 5 to 75 micrometers (microns), the interfilm has an overall wedge angle of at least 0.05 milliradians and 1 milliradian or less, and the interfilm has a spot value of 3.5 or less.

[28] A glazing formed from at least one rigid substrate and the interlayer described in

[22] .

[29] comprising first, second and third polymer layers, The third layer is located between the first layer and the second layer. The first and second layers each have a Tg at least 10°C higher than the glass transition temperature (Tg) of the third layer. A wedge-shaped multilayer interlayer, The first layer has a thickness profile defined by the following formula: [0.0014(D e )+0.06]<T 1 <[1.975141-(1.6936517) / (1+(D e / 155.2664)^3.324064)] [In the formula, D e This is the distance in centimeters from the thinnest edge of the interlayer, T 1 D is measured in millimeters. e This is the thickness of the first layer in [the aforementioned location]. A wedge-shaped multilayer interlayer having [a specific characteristic].

[30] The interlayer according to

[29] , wherein De is 100 cm or less and the total distance between the thinnest edge and the thickest edge is at least 50 cm.

[31] The interlayer according to

[29] , wherein the tapered region constitutes approximately 90% or less of the entire vertical cross-section of the interlayer.

[32] The interlayer according to

[29] , wherein the tapered region is located at or near at least one of the edges of the interlayer.

[33] The interlayer according to

[29] , wherein the interlayer has a thinnest edge and a thickest edge on the opposite side, and further comprises a gradient color band proximal to at least one of the thinnest edge and the thickest edge.

[34] A glazing formed from at least one rigid substrate and the interlayer described in

[29] .

[35] The glazing according to

[34] , wherein the glazing comprises a first and a second rigid substrate, at least one of the first and the second rigid substrates comprises glass, and the first and the second rigid substrates each have a minimum thickness of at least 0.5 mm and / or a maximum thickness of 2.5 mm or less.

[36] The glazing according to

[34] , wherein the first rigid substrate is at least 1.05 times thicker than the second rigid substrate, and / or 10 times or less thicker than the second rigid substrate.

[37] The glazing according to

[34] , wherein at least one of the first and second rigid substrates includes a wedge-shaped substrate.

[38] A first polymer layer having a wedge shape, A second polymer layer, and A third polymer layer between the first layer and the second layer. Includes, The first and second layers each have a Tg at least 10°C higher than the glass transition temperature (Tg) of the third layer. A wedge-shaped multilayer interlayer, The interlayer includes a tapered region having a thinnest edge and a thickest edge, The thickness of the first polymer layer at the thinnest edge of the tapered region is greater than the thickness of the first polymer layer at the thickest edge of the tapered region. Wedge-shaped multilayer interlayer film.

[39] The interlayer according to

[38] , wherein the first layer is at least 10 percent thinner than the second layer over at least 25 percent of the total area of ​​the interlayer.

[40] The interlayer according to

[38] , wherein the first layer has a thickness of less than 0.3 millimeters and the second layer has a thickness of more than 0.3 millimeters over at least 10 percent of the total area of ​​the interlayer.

[41] The interlayer according to

[38] , wherein the interlayer has a thinnest edge and a thickest edge on the opposite side, and the maximum thickness of both the first and second layers does not exceed 0.3 mm within 10 centimeters from the thinnest edge.

[42] The interlayer according to

[38] , wherein at least one of the second polymer layer and the third polymer layer is wedge-shaped.

[43] The interfilm according to

[38] , wherein the first polymer layer has an average thickness smaller than the average thickness of the second polymer layer.

[44] The interlayer film according to

[38] , wherein the thickness of the first polymer layer at the thinnest edge of the tapered region is at least 0.005 mm and / or 0.15 mm greater than the thickness of the second polymer layer at the thinnest edge of the tapered region, and the thickness of the first polymer layer at the thickest edge of the tapered region is at least 0.1 mm and / or 0.4 mm thinner than the thickness of the second polymer layer at the thickest edge of the tapered region.

[45] The interlayer film according to

[38] , wherein the ratio of the thickness of the first polymer layer at the thickest edge of the tapered region to the thickness of the second polymer layer at the thickest edge of the tapered region is at least 0.2:1 and / or 0.99 or less:1, and the ratio of the thickness of the first polymer layer at the thinnest edge of the tapered region to the thickness of the second polymer layer at the thinnest edge of the tapered region is at least 1.05:1 and / or 5 or less:1.

[46] The interlayer according to

[38] , wherein the tapered region is located at or near at least one of the edges of the interlayer.

[47] The interlayer is a three-layer interlayer, the first, second and third layers are each formed from a plasticized polyvinyl acetal resin, the third polymer layer has a plasticizer content that is at least 5 phr (parts per 100 parts of resin) and / or 75 phr or less different from the plasticizer content of the first and / or second polymer layer, the third polymer layer has a glass transition temperature (Tg) that is at least 2°C and / or 50°C or less different from the glass transition temperature (Tg) of the first and / or second polymer layer, the polyvinyl acetal contains polyvinyl butyral, and the first The interfilm according to

[38] , wherein the polyvinyl butyral in the second layer has a residual acetate content of less than 15 weight percent, the maximum difference in the residual hydroxyl content of the polyvinyl butyral in the first or second and third polymer layers is at least 3 percent, at least a portion of the surface of the interfilm has a surface roughness (Rz) of 5 to 75 micrometers (microns), the interfilm has an overall wedge angle of at least 0.05 milliradians and 1 milliradian or less, and the interfilm has a spot value of 3.5 or less.

[48] ​​A glazing formed from at least one rigid substrate and the interlayer described in

[38] .

[49] comprising first, second and third polymer layers, The third layer is located between the first layer and the second layer, and at least one of the first and second layers is wedge-shaped. A wedge-shaped multilayer interlayer, The interlayer has a tapered region having a thinnest edge and a thickest edge, All points along the vertical center line extending between the thinnest and thickest edges have the following relationship: 1.25Tca > TcL > 0.75Tca [In the formula, TcL is the local combined thickness of the first and second layers, and Tca is the average combined thickness of the first and second layers, calculated as follows: Tca = (Tc1 + Tc2) / 2 In the formula, Tc1 is the combined thickness of the first and second layers at the thinnest edge, and Tc2 is the combined thickness of the first and second layers at the thickest edge. A wedge-shaped multilayer interlayer that satisfies the following conditions.

[50] The interlayer according to

[49] , wherein the first and second polymer layers are each wedge-shaped.

[51] The interlayer according to

[49] , wherein the first polymer layer has a thickness greater than the thickness of the second polymer layer at the thinnest edge of the tapered region, and the first polymer layer has a thickness less than the thickness of the second polymer layer at the thickest edge of the tapered region.

[52] The interlayer film according to

[49] , wherein the thickness of the first polymer layer at the thinnest edge of the tapered region is at least 0.005 mm and / or 0.15 mm greater than the thickness of the second polymer layer at the thinnest edge of the tapered region, and the thickness of the first polymer layer at the thickest edge of the tapered region is at least 0.1 mm and / or 0.4 mm thinner than the thickness of the second polymer layer at the thickest edge of the tapered region.

[53] The interlayer according to

[49] , wherein the tapered region is located at or near at least one of the edges of the interlayer.

[54] The interlayer film according to

[49] , wherein the ratio of the thickness of the second polymer layer to the thickness of the thickest edge of the tapered region is at least 0.20:1 and / or 0.85 or less:1, the ratio of the thickness of the first polymer layer to the thickness of the thickest edge of the tapered region is at least 0.1:1 and / or 0.45 or less:1, and the ratio of the thickness of the third polymer layer to the thickness of the thickest edge of the tapered region is at least 0.05:1 and / or 0.40 or less:1.

[55] The interlayer according to

[49] , wherein at least one of the first, second, and third layers comprises an IR absorber.

[56] The interlayer is a three-layer interlayer, the first, second and third layers are each formed from a plasticized polyvinyl acetal resin, the third polymer layer has a plasticizer content that is at least 5 phr (parts per 100 parts of resin) and / or 75 phr or less different from the plasticizer content of the first and / or second polymer layer, the third polymer layer has a glass transition temperature (Tg) that is at least 2°C and / or 50°C or less different from the glass transition temperature (Tg) of the first and / or second polymer layer, the polyvinyl acetal contains polyvinyl butyral, and the first The interfilm according to

[49] , wherein the polyvinyl butyral in the second layer has a residual acetate content of less than 15 weight percent, the maximum difference in the residual hydroxyl content of the polyvinyl butyral in the first or second and third polymer layers is at least 3 percent, at least a portion of the surface of the interfilm has a surface roughness (Rz) of 5 to 75 micrometers (microns), the interfilm has an overall wedge angle of at least 0.05 milliradians and 1 milliradian or less, and the interfilm has a spot value of 3.5 or less.

[57] A glazing formed from at least one rigid substrate and the interlayer described in

[49] .

[58] comprising first, second and third polymer layers, The third layer is located between the first layer and the second layer, and at least one of the first and second layers is wedge-shaped. A wedge-shaped multilayer interlayer, The interlayer includes a tapered region having a thinnest edge and a thickest edge, The first layer has a thickness that increases from the thinnest edge to the thickest edge of the tapered region, The second layer has a thickness that decreases from the thinnest edge to the thickest edge of the tapered region, At least one of the first, second, and third layers contains at least one IR absorbent, Wedge-shaped multilayer interlayer film.

[59] The interfilm according to

[58] , wherein the first, second, and third polymer layers are each wedge-shaped.

[60] The interlayer according to

[58] , wherein the IR absorber comprises a compound containing copper, vanadium, zinc, or a combination thereof.

[61] The interlayer film according to

[58] , comprising metal oxide particles as the IR absorber.

[62] The interlayer according to

[58] , wherein the IR absorber comprises one or more of indium tin oxide, antimony tin oxide, lanthanum hexaboride, and cesium tungsten oxide.

[63] The interlayer film according to

[58] , wherein the IR absorber comprises metal oxide particles selected from the group consisting of aluminum-doped tin oxide, indium-doped tin oxide (ITO), antimond-doped tin oxide (ATO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), aluminum-doped zinc oxide (AZO), niobium-doped titanium oxide, sodium-doped tungsten oxide, cesium-doped tungsten oxide, thallium-doped tungsten oxide, rubidium-doped tungsten oxide, tin-doped indium oxide, tin-doped zinc oxide particles, silicon-doped zinc oxide, lanthanum hexaboride (LaB6), and combinations thereof.

[64] The interlayer film according to

[58] , wherein the IR absorbent comprises particles having an average particle size of 100 nm or less.

[65] The interlayer according to

[58] , wherein at least a portion of the IR absorber is present in the first and / or second polymer layer.

[66] The interlayer according to

[58] , wherein at least a portion of the IR absorber is present in the third polymer layer.

[67] The interlayer is a three-layer interlayer, the first, second and third layers are each formed from a plasticized polyvinyl acetal resin, the third layer has a plasticizer content that is at least 5 phr (parts per 100 parts of resin) and / or 75 phr or less different from the plasticizer content of the first and / or second polymer layer, the third polymer layer has a glass transition temperature (Tg) that is at least 2°C and / or 50°C or less different from the glass transition temperature (Tg) of the first and / or second polymer layer, the polyvinyl acetal contains polyvinyl butyral, and the first The interfilm according to

[58] , wherein the polyvinyl butyral in the second layer has a residual acetate content of less than 15 weight percent, the maximum difference in the residual hydroxyl content of the polyvinyl butyral in the first or second and third polymer layers is at least 3 percent, at least a portion of the surface of the interfilm has a surface roughness (Rz) of 5 to 75 micrometers (microns), the interfilm has an overall wedge angle of at least 0.05 milliradians and 1 milliradian or less, and the interfilm has a spot value of 3.5 or less.

[68] A glazing formed from at least one rigid substrate and the interlayer described in

[58] .

[69] comprising first, second and third polymer layers, The third layer is located between the first layer and the second layer, and at least one of the first and second layers is wedge-shaped. A wedge-shaped multilayer interlayer, The interlayer has a thinnest edge portion, a thickest edge portion, and a tapered region having an overall wedge angle of at least 0.30 mrad. The total solar transmittance (%Tts) measured at the thickest edge of the tapered region is within approximately 3% of the total solar transmittance measured at the thinnest edge of the tapered region. At least one of the first, second, and third polymer layers contains an IR absorber, and each of the layers containing the IR absorber is formed from the same polymer material at both the thinnest and thickest edges of the tapered region. Wedge-shaped multilayer interlayer film.

[70] The interlayer according to

[69] , wherein the first and second polymer layers are each wedge-shaped.

[71] The interlayer according to

[69] , wherein the interlayer has a thinnest edge and a thickest edge on the opposite side, and the maximum thickness of both the first and second layers does not exceed 0.3 mm within 10 centimeters from the thinnest edge.

[72] The interlayer according to

[69] , wherein the first layer is wedge-shaped and has a thick end and a thin end, the thick end of the first layer is at the thinnest edge of the tapered region and the thin end of the first layer is at the thickest edge of the tapered region.

[73] The interlayer according to

[69] , wherein at least one of the first, second, and third polymer layers comprises an IR absorber.

[74] The interlayer according to

[73] , wherein the first and second polymer layers each contain an IR absorbent, the IR absorbent comprising metal oxide particles selected from the group consisting of aluminum-doped tin oxide, indium-doped tin oxide (ITO), antimond-doped tin oxide (ATO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), aluminum-doped zinc oxide (AZO), niobium-doped titanium oxide, sodium-doped tungsten oxide, cesium-doped tungsten oxide, thallium-doped tungsten oxide, rubidium-doped tungsten oxide, tin-doped indium oxide, tin-doped zinc oxide particles, silicon-doped zinc oxide, lanthanum hexaboride (LaB6), and combinations thereof.

[75] The interlayer is a three-layer interlayer, the first, second and third layers are each formed from a plasticized polyvinyl acetal resin, the third polymer layer has a plasticizer content that is at least 5 phr (parts per 100 parts of resin) and / or 75 phr or less different from the plasticizer content of the first and / or second polymer layer, the third polymer layer has a glass transition temperature (Tg) that is at least 2°C and / or 50°C or less different from the glass transition temperature (Tg) of the first and / or second polymer layer, the polyvinyl acetal contains polyvinyl butyral, and the first The interfilm according to

[69] , wherein the polyvinyl butyral in the second layer has a residual acetate content of less than 15 weight percent, the maximum difference in the residual hydroxyl content of the polyvinyl butyral in the first or second and third polymer layers is at least 3 percent, at least a portion of the surface of the interfilm has a surface roughness (Rz) of 5 to 75 micrometers (microns), the interfilm has an overall wedge angle of at least 0.05 milliradians and 1 milliradian or less, and the interfilm has a spot value of 3.5 or less.

[76] A glazing formed from at least one rigid substrate and the interlayer described in

[69] .

[77] A method for producing a multilayer interlayer film, (a) A step of preparing the skin resin, (b) A step of preparing a core resin having a different composition from the skin resin, (c) A step of forming a first skin layer from a portion of the skin resin and a second skin layer from another portion of the skin resin, comprising supplying the resin used to form the first skin layer to the die at a mass flow rate lower than the mass flow rate of the skin resin used to form the second skin polymer layer, (d) The step of forming a core layer from at least a portion of the core resin, (e) The step of forming a multilayer polymer layer from the first skin layer, the second skin layer and the core layer, Includes, At one or more locations of the multilayer interlayer, the first skin layer is at least 10 percent thicker than the second skin layer. method.

[78] The method according to

[77] , wherein the interlayer has a thinnest edge and a thickest edge on the opposite side, and the maximum thickness of at least one of the first and second layers does not exceed 0.3 mm within 10 centimeters from the thinnest edge.

[79] Different mass flow rates used for forming the first and second skin layers are described in the following techniques (i) to (iv): (i) Using separate pumps to individually control the mass flow rate of the resin used to form the first and second skin layers, (ii) Using separate extruders to individually control the mass flow rate of the resin used to form the first and second skin layers, (iii) Transporting the resin used to form the first and second skin layers using melt pipes of different average cross-sectional areas, and (iv) Using a flow restrictor, reduce the mass flow rate of the resin used to form the first skin layer compared to the mass flow rate of the resin used to form the second skin layer. The method described in

[77] , provided by one or more of the following.

[80] The method according to

[77] , wherein the supply in step (c) involves passing the first skin resin and the second skin resin through first and second melt pipes, respectively, the first and second melt pipes having different average cross-sectional flow areas along at least a portion of their lengths.

[81] The method according to

[77] , wherein the mass flow rate of the resin used to form the first skin layer is 95 percent or less of the mass flow rate of the resin used to form the second skin layer.

[82] The first and second skin layers and the core layer each comprise a plasticized polyvinyl acetal resin layer, wherein the core layer has a plasticizer content that differs from the plasticizer content of the first and / or second skin layers by at least 5 phr (parts per 100 parts of resin) and / or 75 phr or less, the core layer has a glass transition temperature (Tg) that differs from the glass transition temperature (Tg) of the first and / or second skin layers by at least 2°C and / or 50°C or less, and the polyvinyl acetal comprises polyvinyl butyral, and the first and second skin layers The method according to

[77] , wherein the polyvinyl butyral in the skin layer has a residual acetate content of less than 15 weight percent, the maximum difference in the residual hydroxyl content of the polyvinyl butyral in the first or second skin layer and the core layer is at least 3 percent, at least a portion of the surface of the interlayer has a surface roughness (Rz) of 5 to 75 micrometers (microns), the interlayer has an overall wedge angle of at least 0.05 milliradians and 1 milliradian or less, and the interlayer has a spot value of 3.5 or less.

Claims

1. A first polymer layer having a wedge shape, A second polymer layer having a wedge shape, and A third polymer layer between the first polymer layer and the second polymer layer. Includes, The first and second polymer layers each have a Tg that is at least 10°C higher than the glass transition temperature (Tg) of the third polymer layer. A wedge-shaped multilayer interlayer, At one or more locations of the wedge-shaped multilayer interlayer, the second polymer layer is at least 10 percent thicker than the first polymer layer. Throughout the wedge-shaped multilayer interfilm, the first polymer layer has a thickness of less than 0.30 mm, and the second polymer layer has a thickness of more than 0.30 mm. A wedge-shaped multilayer interlayer having a mottling value of 3.5 or less.

2. The wedge-shaped multilayer interfilm according to claim 1, wherein the wedge-shaped multilayer interfilm has a thinnest edge portion and a thickest edge portion, and the maximum thickness of at least one of the first and second polymer layers does not exceed 0.3 mm within 40 centimeters from the thinnest edge portion.

3. The wedge-shaped multilayer interfilm according to claim 1, wherein the ratio of the thickness of the first polymer layer to the thickness of the thinnest edge of the tapered region is at least 0.20:1 and / or 0.85 or less:1, and the ratio of the thickness of the second polymer layer to the thickness of the thinnest edge of the tapered region is at least 0.1:1 and / or 0.45 or less:

1.

4. The wedge-shaped multilayer interlayer is a three-layer interlayer, the first, second, and third polymer layers are each formed from a plasticized polyvinyl acetal resin, the third polymer layer has a plasticizer content that is at least 5 phr (parts per 100 parts of resin) and / or 75 phr or less different from the plasticizer content of the first and / or second polymer layer, the third polymer layer has a glass transition temperature (Tg) that is at least 2°C and / or 50°C or less different from the glass transition temperature (Tg) of the first and / or second polymer layer, and the plasticized polyvinyl acetal resin contains polyvinyl butyral, and the first and the The wedge-shaped multilayer interfilm according to claim 1, wherein the polyvinyl butyral in the second polymer layer has a residual acetate content of less than 15 weight percent, the maximum difference in the residual hydroxyl content of the polyvinyl butyral in the first or second and third polymer layers is at least 3 percent, at least a portion of the surface of the wedge-shaped multilayer interfilm has a surface roughness (Rz) of 5 to 75 micrometers (microns), the wedge-shaped multilayer interfilm has an overall wedge angle of at least 0.05 milliradians and 1 milliradian or less, and the wedge-shaped multilayer interfilm has a spot value of 3.5 or less.

5. It comprises first, second, and third polymer layers, The third polymer layer is located between the first polymer layer and the second polymer layer. The first and second polymer layers each have a Tg that is at least 10°C higher than the glass transition temperature (Tg) of the third polymer layer. A wedge-shaped multilayer interlayer, The first polymer layer has a thickness profile defined by the following formula: [0.0014(D ｅ )+0.06]<T １ <[1.975141-(1.6936517) / (1+(D ｅ / 155.2664)^3.324064)] [In the formula, D ｅ This is the distance in centimeters from the thinnest edge of the wedge-shaped multilayer interlayer, T １ D is measured in millimeters. ｅ This is the thickness of the first polymer layer in the above, where D e is 100 cm or less. It has, Throughout the wedge-shaped multilayer interfilm, the first polymer layer has a thickness of less than 0.30 mm, and the second polymer layer has a thickness of more than 0.30 mm. A wedge-shaped multilayer interlayer having a mottling value of 3.5 or less.

6. The wedge-shaped multilayer interlayer according to claim 5, wherein the total distance between the thinnest edge and the thickest edge is at least 50 cm.

7. It comprises first, second, and third polymer layers, The third polymer layer is located between the first polymer layer and the second polymer layer, and at least one of the first and second polymer layers is wedge-shaped. The first and second polymer layers each have a Tg that is at least 10°C higher than the glass transition temperature (Tg) of the third polymer layer. A wedge-shaped multilayer interlayer, The wedge-shaped multilayer interfilm has a tapered region having a thinnest edge and a thickest edge, All points along the vertical center line extending between the thinnest and thickest edges have the following relationship: 1.25Tca>TcL>0.75Tca [In the formula, TcL is the local combined thickness of the first and second polymer layers, and Tca is the average combined thickness of the first and second polymer layers, calculated as follows: Tca=(Tc1+Tc2) / 2 In the formula, Tc1 is the combined thickness of the first and second polymer layers at the thinnest edge, and Tc2 is the combined thickness of the first and second polymer layers at the thickest edge. Satisfying the conditions, Throughout the wedge-shaped multilayer interfilm, the first polymer layer has a thickness of less than 0.30 mm, and the second polymer layer has a thickness of more than 0.30 mm. A wedge-shaped multilayer interlayer having a mottling value of 3.5 or less.

8. The wedge-shaped multilayer interfilm according to claim 7, wherein at least one of the first, second, and third polymer layers contains an IR absorbent.

9. The wedge-shaped multilayer interfilm according to claim 8, wherein the IR absorbent contains metal oxide particles.

10. The wedge-shaped multilayer interfilm according to claim 8, wherein the IR absorbent comprises particles having an average particle size of 100 nm or less.

11. It comprises first, second, and third polymer layers, The third polymer layer is located between the first polymer layer and the second polymer layer, and at least one of the first and second polymer layers is wedge-shaped. The first and second polymer layers each have a Tg that is at least 10°C higher than the glass transition temperature (Tg) of the third polymer layer. A wedge-shaped multilayer interlayer, The wedge-shaped multilayer interfilm has a thinnest edge portion, a thickest edge portion, and a tapered region having an overall wedge angle of at least 0.30 mrad. The total solar transmittance (%Tts) measured at the thickest edge of the tapered region is within 3% of the total solar transmittance measured at the thinnest edge of the tapered region. At least one of the first, second, and third polymer layers contains an IR absorbent, and each of the layers containing the IR absorbent is formed from the same polymer material at both the thinnest and thickest edges of the tapered region. Throughout the wedge-shaped multilayer interfilm, the first polymer layer has a thickness of less than 0.30 mm, and the second polymer layer has a thickness of more than 0.30 mm. A wedge-shaped multilayer interlayer having a mottling value of 3.5 or less.

12. The wedge-shaped multilayer interlayer according to claim 11, wherein the first polymer layer is wedge-shaped and has a thick end and a thin end, the thick end of the first polymer layer is at the thinnest edge of the tapered region, and the thin end of the first polymer layer is at the thickest edge of the tapered region.

13. A glazing formed from at least one rigid substrate and a wedge-shaped multilayer interlayer according to any one of claims 1 to 12.

Images