Optical intermediate layer and method for manufacturing the same

Abstract

Optical interlayers, laminate composites, and improved methods for manufacturing the optical interlayers and laminate composites are provided. The optical interlayer film has at least one surface with an embossed surface pattern having at least two grooves extending in at least two non-parallel directions. The grooves have a depth of greater than about 20 μm. The surface pattern allows for the removal of air between the interlayer and the outer laminate sheet, thereby establishing the necessary seal while minimizing premature edge sealing. The laminate composites are particularly useful for safety glazing in a variety of applications, such as transportation vehicles (e.g., automobiles, airplanes, and trains), display devices, windows in buildings (e.g., homes), building facades, cabinets, and / or load-bearing architectural structures (e.g., stairs and floors).

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 419,259, filed October 25, 2022, the entire disclosure of which is incorporated by reference into this disclosure for all purposes.

[0002] (Field) The present invention relates generally to optical interlayers and laminated composites, such as laminated safety glass, and methods for making such interlayers and composites. [Background technology]

[0003] Glass has been widely used in various buildings, vehicles, and display devices due to its transparency, airtightness, high strength, and hardness. To enhance the safety and applicability of glass, it has become common practice to place a sheet or film of a thermoplastic interlayer material between two panes of glass. When such laminated glass is subjected to external impact, the glass may break, but the interlayer sandwiched between the constituent panes of glass is not easily destroyed. Even after breakage, the glass remains bonded to the interlayer, preventing it from scattering. Therefore, occupants of the vehicle or building are protected from injury caused by broken glass fragments. Laminated glass is typically produced by inserting an interlayer between two glass sheets and stretching the assembly over nip rolls or by placing the assembly in a rubber bag and applying a vacuum to the bag to effect a preliminary contact bond between the glass sheets and the interlayer, with the final contact bond then being effected at elevated temperature and pressure in an autoclave. Interlayer materials typically have a roughened or embossed surface pattern to minimize sticking of one layer to another. This surface pattern also allows the interlayer to move during alignment of the two panes of glass when constructing an assembly. Unfortunately, this roughening of the interlayer surface can cause air to become trapped in the gap between the glass surface and most thermoplastic interlayers. Trapped air can be removed by vacuum evacuation or by sandwiching the assembly between a set of rollers. The extent to which air must be removed from between the glass and the interlayer depends on the nature of the interlayer and the intended use. The presence of a gas phase within the laminate takes the form of bubbles or gas pockets between the interlayer and the glass interface. These bubbles or gas pockets can increase the haze and / or reduce the light transmission of the laminate, making it less than optimal for end uses in which the laminate functions as a transparent article, such as safety glass. For certain applications, laminators have faced challenges in selecting a suitable interlayer and a suitable surface pattern for the interlayer. For example, a rougher interlayer will degas faster. However, because it typically requires more energy to consolidate a rough interlayer, it can be difficult to achieve a sufficient edge seal with such an interlayer. If the edges of the pre-press are not completely sealed, air can enter the edges during the autoclave process, in which the pre-press is heated under high pressure, resulting in commercially unacceptable appearance defects in the laminate. Furthermore, interlayers that are rough and allow for rapid degassing near room temperature (23°C) often do not degas sufficiently when ambient temperatures are significantly above 30°C. On the other hand, relatively smooth interlayers can develop edge seals before sufficient air is removed, leaving air trapped inside the pre-press. This problem is commonly referred to as premature edge seal and is particularly prevalent with plasticized interlayers such as PVB. During autoclaving, excess air may be forced into the solution under high pressure, but can return to the gas phase after autoclaving. Defects that occur after lamination are often more costly to correct.

[0004] It would be desirable to provide an improved optical interlayer having a roughened and / or embossed surface that allows for the removal of trapped air between the interlayer and the skin of the laminate composite. In particular, it would be desirable to provide an embossed or roughened surface that provides the necessary seal between the interlayer and the skin while minimizing premature edge sealing that would leave trapped air or gas in the gap between the interlayer and the skin. Summary of the Invention

[0005] The following presents a simplified summary of the claimed subject matter in order to provide a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview of the claimed subject matter, and is not intended to identify essential elements or delineate the scope of the claimed subject matter. Its sole purpose is to present some concepts of the claimed subject matter as a prelude to the more detailed description that is presented later.

[0006] Optical interlayers, laminate composites, and methods for manufacturing such interlayers and composites are provided. In various embodiments, the optical interlayers described herein have an embossed or roughened surface that allows for the removal of air between the interlayer and one or more exterior laminates when the interlayer is used, for example, in a laminate composite. This establishes the necessary seal between the interlayer and the exterior laminate while minimizing premature edge sealing. In various embodiments, the laminate composites described herein have relatively low haze and high light transmission, making them particularly useful for a variety of applications that may require optically clear laminates, such as safety glazing in automobile, airplane, train, or other transportation windows, display devices, home and other building windows, building facades, cabinets, and / or load-bearing architectural structures such as stairs and floors.

[0007] In one embodiment, the optical interlayer film comprises at least one surface having an embossed surface pattern having at least two channels extending in at least two non-parallel directions, the channels having a depth greater than about 20 μm. In various embodiments, the grooves have a depth of greater than about 30 μm or from about 30 μm to about 50 μm, preferably from about 35 μm to about 43 μm. The grooves have a width of from about 30 μm to about 900 μm or from about 400 μm to about 600 μm. The width may be measured, for example, from the midpoint of the groove depth. The intermediate layer may comprise an unplasticized thermoplastic material or a plasticized thermoplastic material. In certain embodiments, the intermediate layer comprises an unplasticized thermoplastic material. Suitable thermoplastic materials include a polyurethane intermediate layer, an ethylene vinyl acetate intermediate layer, an ethylene acid copolymer intermediate layer, an ionoplastic material, or a combination thereof. In an exemplary embodiment, the material comprises an unplasticized thermoplastic polyurethane (TPU). The interlayer film may have a second surface opposite the first surface. The second surface has an embossed surface pattern having at least two grooves extending in at least two non-parallel directions. The grooves have a depth of greater than about 20 μm or greater than about 30 μm. The second embossed pattern may be the same as or different from the first embossed pattern. For example, the embossed pattern and / or its depth may be asymmetric with respect to the two sides of the interlayer film. The grooves may be formed by embossing a projection onto the base surface of the interlayer film. In some embodiments, depressions or voids are also formed in the base surface. This configuration reduces the energy required to flatten the interlayer, for example, an interlayer between two rigid sheets in a laminate. In these embodiments, the depth of the groove is measured from the peak of the projection to the lowest point or valley of the depression. In various embodiments, the embossed pattern comprises a first plurality of grooves extending in a first direction and spaced apart from one another by a distance of about 100 μm to about 1,000 μm, and a second plurality of grooves extending in a second direction and spaced apart from one another by a distance of about 100 μm to about 1,000 μm. The first set of grooves extends in a non-parallel direction relative to the second set of grooves. In an exemplary embodiment, the first set of grooves is substantially perpendicular to the second set of grooves.

[0008] The optical interlayer film may have a thickness of less than about 0.08 inches. In certain embodiments, the thickness is less than about 0.02 inches, or about 0.014 to about 0.017 inches, or about 0.15 inches. In embodiments, the embossed surface of the interlayer film has an 85-degree gloss of about 14 to about 20, or about 15 to about 17. The optical interlayer films provided herein are particularly useful in laminates comprising first and second substantially rigid sheets on either side of the interlayer film. The rigid sheets may include a rigid plastic material, such as polycarbonate, and / or glass. The embossed surface pattern of the interlayer provides a plurality of substantially continuous grooves for degassing in at least two directions between the interlayer and the outer rigid sheets. The depth of the grooves allows air to escape during the lamination process without prematurely sealing the edges of the interlayer to the glass. The resulting laminate has sufficiently low haze and high light transmittance to function as safety glass in a variety of applications.

[0009] In another aspect, a laminate comprises at least one glass layer and an interlayer film bonded to the glass layer, the interlayer film having at least one surface facing the glass layer with an embossed surface pattern having at least two grooves extending in at least two non-parallel directions, the grooves having a depth greater than about 20 μm or greater than about 30 μm prior to lamination. In various embodiments, the laminate includes a second glass layer, and the interlayer film is disposed between the first and second glass layers. The interlayer film has a second surface opposite the first surface facing the second glass layer. The second surface has an embossed surface pattern having at least two grooves extending in at least two non-parallel directions. The grooves have a depth of greater than about 20 μm or greater than about 30 μm before lamination. In various embodiments, the intermediate layer comprises an unplasticized thermoplastic material. Suitable thermoplastic materials include a polyurethane intermediate layer, an ethylene vinyl acetate intermediate layer, an ethylene acid copolymer intermediate layer, an ionoplastic material, or a combination thereof. In an exemplary embodiment, the material comprises an unplasticized TPU.

[0010] In various embodiments, the laminate has a relatively low haze (measured by ASTM D1003) of from about 0.8% to about 0.9%, or from about 0.82% to about 0.86%, or about 0.84% ​​after lamination. In various embodiments, the laminate has a relatively high light transmittance (as measured by ASTM D1003) of about 85% to about 95%, or about 89% to about 90% after lamination. The laminate may have one optical interlayer film or multiple interlayer films sandwiched between outer rigid sheets (i.e., glass or polycarbonate). In the latter embodiment, each of the interlayer films may include a surface pattern, as described above, on one or both sides of the interlayer film.

[0011] In another embodiment, a method for producing an optical intermediate layer film includes forming an embossed pattern on a calendar roll and transferring the embossed pattern to a surface of the optical intermediate layer film such that the surface has at least two grooves extending in at least two non-parallel directions, the grooves having a depth of greater than about 20 μm. In various embodiments, the calender rolls may comprise metal, rubber, or a combination thereof. In an exemplary embodiment, the calender rolls comprise a metal roll and a rubber roll. The metal roll is engraved with a surface pattern and pressed against the surface of the interlayer while the rubber roll is pressed against the opposite side of the interlayer. In an embodiment, the method further includes transferring a second embossed pattern to a second surface of the interlayer film opposite the first surface. The second embossed pattern can be the same as or different from the first embossed pattern. In an exemplary embodiment, the second embossed pattern has at least two grooves extending in at least two non-parallel directions, the grooves having a depth greater than about 20 μm. The method may further include disposing an optical interlayer film between a first glass sheet and a second glass sheet to obtain a laminate structure, and vacuum laminating the laminate structure to remove air trapped between the interlayer film and the glass sheets.

[0012] Reference in this disclosure to desirable objectives achieved by various embodiments of the present description is not meant to imply or suggest that any or all of these objectives, either individually or collectively, are present as essential features in either the most general embodiment of the present description or in any of the more specific embodiments. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram of a surface pattern on one surface of an optical interlayer. [Figure 2] FIG. 1 is a top view of the surface pattern of an optical interlayer measured along a diagonal of the interlayer. [Figure 3] 3 is a graph showing the height and width of the grooves along the diagonal lines of FIG. 2. [Figure 4] 10 is a graph showing the frequency distribution of St or peak heights of grooves formed on the surfaces of multiple optical intermediate layers. DETAILED DESCRIPTION OF THE INVENTION

[0014] This description and the accompanying drawings illustrate exemplary embodiments and should not be taken as limiting, with the claims defining the scope of this description, including equivalents. Various mechanical, compositional, structural, and operational changes, including equivalents, may be made without departing from the scope of this description and claims. In some instances, well-known structures and techniques have not been shown or described in detail to avoid obscuring the description. Like numbers in two or more drawings represent the same or similar elements. Furthermore, elements and related aspects described in detail with reference to one embodiment may, whenever practical, be included in other embodiments not specifically shown or described. For example, even if an element is described in detail with reference to one embodiment and not with reference to a second embodiment, the element may still be claimed to be included in the second embodiment. Furthermore, the depictions in this disclosure are for illustrative purposes only and do not necessarily reflect the actual shape, size, or dimensions of the systems or illustrated components. As used in this disclosure and the appended claims, please note that the singular forms "a," "an," and "the," as well as the use of any singular form of any word, include plural references unless expressly and unambiguously limited to one reference. As used in this disclosure, the term "include" and its grammatical variations are intended to be open-ended, and the recitation of items in a list does not exclude other similar items that may be substituted for or added to the items in the list. Unless otherwise specified, any quantitative value is approximate, whether or not indicated by words such as "about" or "approximately." The materials, methods, and examples described in this disclosure are illustrative only and are not intended to be limiting.

[0015] Optical interlayers and laminate composites, such as safety glass laminates, are provided. Additionally, improved methods for manufacturing optical interlayers and laminate composites are provided. Various embodiments of the systems and methods described herein have embossed or roughened surfaces that allow for the removal of air between the interlayer and the glass, thereby establishing the necessary seal between the interlayer and the glass while minimizing premature edge sealing. The optical interlayers described herein are thermoplastic interlayers that can be heated to form adhesive bonds with other interlayer materials, rigid plastic materials, and / or glass. Laminates comprising the interlayers described herein are particularly useful as safety glazing in a variety of applications. For example, these laminates may be suitable for use in vehicles with windows or transparent openings, such as automobiles, airplanes, and trains, where safety glazing can be used to protect the vehicle's occupants or contents. Other suitable applications for safety glazing are well known, including, for example, windows in buildings such as homes, building facades, cabinets, and / or load-bearing architectural structures such as stairs and floors.

[0016] The appearance and clarity of a transparent laminate are important characteristics in assessing the desirability of its use. One factor that influences the appearance of the laminate is whether the laminate contains air or bubbles trapped between, for example, the interlayer and the glass surface. It is desirable to efficiently remove air during the lamination process. Providing channels for air escape and removal during lamination is a known method for obtaining laminates with an acceptable appearance. This can be accomplished by mechanically embossing the interlayer sheet (or by melt fracture during extrusion), followed by quenching so that the rough surface is maintained during processing. Retention of surface roughness is essential to facilitate effective degassing of trapped air during laminate fabrication. The interlayer comprises an unplasticized or plasticized thermoplastic material. In certain embodiments, the material is an unplasticized material. Suitable thermoplastic materials include polyurethane interlayers, ethylene vinyl acetate interlayers, ethylene acid copolymer interlayers, ionoplastics, and the like. In an exemplary embodiment, the material comprises unplasticized thermoplastic polyurethane (TPU). TPU is a class of polyurethane plastics that has many properties, including elasticity, transparency, and resistance to oil, grease, and abrasion.

[0017] The surface pattern is preferably an embossed pattern. The groove depth is about 20 μm to about 80 μm. Preferably, the grooves have a depth of greater than about 30 μm or about 30 μm to about 50 μm, preferably about 35 μm to about 43 μm. The depth is preferably selected so that the regular grooves provide suitable paths for air to escape during the lamination process. Therefore, the depth should be sufficient to prevent premature cutting of paths during the heating stage of the lamination process, thereby preventing air from becoming trapped within the laminate upon cooling. The interlayer sheet can be embossed on one or both sides. The embossed pattern and / or its depth may be asymmetric with respect to the two sides of the interlayer sheet. That is, the embossed patterns, as well as the pattern depth on both sides of the sheet, may be the same or different. In a preferred embodiment, the interlayer sheet of the present invention has an embossed pattern on both sides, with the pattern depth on each side being greater than about 20 μm. In certain embodiments, the embossed pattern is present on the side of the interlayer sheet perpendicular to the edge of the sheet, with the same embossed pattern inclined at an angle greater than or less than 90° relative to the edge, and the embossed pattern depth is greater than about 20 μm. By offsetting the patterns in this manner, undesirable optical effects can be eliminated during sheet formation. The groove width may be measured at the midpoint between the top and bottom of the groove (i.e., half the distance between the valley depth and peak height, as defined below). At this midpoint, the groove has a width of about 30 μm to about 900 μm, or about 400 μm to about 600 μm. In an embodiment, the embossed pattern comprises a first plurality of grooves extending in a first direction and spaced apart from one another by a distance of about 100 μm to about 1,000 μm or about 300 μm to about 800 μm, preferably about 500 μm to about 700 μm. The embossed pattern may comprise a second plurality of grooves extending in a second direction and spaced apart from one another by a distance of about 100 μm to about 1,000 μm or about 300 μm to about 800 μm, preferably about 500 μm to about 700 μm. The first grooves extend in a direction non-parallel to the second grooves. In an exemplary embodiment, the first grooves are substantially perpendicular to the second grooves. Of course, it will be appreciated that other patterns may be formed in the intermediate layer, for example the surface pattern may include three or more sets of different grooves extending in three or more directions.

[0018] 1, an example of a surface pattern on an optical interlayer 10 is provided, with a base surface 30 generally representing the original substantially flat surface of the interlayer prior to the formation of the surface pattern. The surface pattern includes protrusions 20 extending upward from the base surface 30 and voids or depressions 40 on the interlayer surface 30. Such protrusions 20 and depressions 30 may have different volumes or may have substantially the same volume, and may be located near other such protrusions and voids on the interlayer surface. The peaks and valleys are preferentially positioned so that heating and compression of the interlayer surface results in a more localized flow of thermoplastic material from areas of higher thermoplastic mass (i.e., peaks) to areas of voids (i.e., valleys), filling such voids with mass from nearby peaks, resulting in a planarization of the interlayer surface. Obtaining a planarized surface with localized flow of thermoplastic material requires less energy investment than conventional patterns (i.e., patterns with only peaks and no valleys) that require a mass flow of thermoplastic material across the entire surface of the interlayer to planarize the surface. In an alternative embodiment, the surface pattern includes only protrusions (i.e., no recesses). In this embodiment, the groove depth is measured from the base surface 30 to the top of the protrusions 30. The optical interlayer film can have a thickness of less than about 0.08 inches. In certain embodiments, the thickness is less than about 0.02 inches, or from about 0.014 to about 0.017 inches, or about 0.15 inches.

[0019] In one embodiment, the average peak height or S p is in the range of about 5 μm to about 50 μm, or about 20 μm to about 40 μm, preferably about 25 μm to about 30 μm. v is in the range of about 5 μm to about 40 μm, or about 10 μm to about 20 μm, preferably about 12 μm to about 16 μm. Therefore, the average height of each groove (i.e., the distance from the peak height to the valley depth) is greater than about 30 μm, or about 30 μm to about 50 μm, preferably about 35 μm to about 43 μm. The kurtosis of the surface pattern (i.e., a measure of the combined weight of the tails of the distribution relative to the center of the distribution) is preferably less than about 5.0, or less than about 3.0. The skewness of the surface pattern (i.e., a measure of the symmetry of the probability distribution about the mean height) is preferably from about 0.8 to about 0.85. An example of the peak heights and valley depths of the surface pattern is shown in Table 1 below. [Table 1] As shown in Table 1 above, the arithmetic mean height S of this sample a The mean squared height was about 9.487 μm, the kurtosis (i.e., a measure of the combined weight of the tails of the distribution relative to the center of the distribution) was about 2.551, and the skewness (i.e., a measure of the symmetry of the probability distribution about the mean height) was about 0.8216.

[0020] The surface pattern created in the intermediate layer increases the gloss of that surface. In one embodiment, the 85-degree gloss of the embossed surface of the intermediate layer is from about 12 to about 20, or from about 15 to about 17. In certain embodiments, the embossed surface pattern increases the 85-degree gloss of the intermediate layer by from about 10 to about 15, or from about 12 to about 13. The optical interlayer film is particularly useful in laminates comprising first and second substantially rigid sheets on either side of the interlayer film. Rigid sheets can include rigid plastic materials such as polycarbonate and / or glass. In one embodiment, the sheets comprise annealed glass having a thickness of about 2.5 mm to about 5.0 mm, or about 3.0 mm to about 3.5 mm. The laminate may have one optical interlayer film or multiple interlayer films sandwiched between outer rigid sheets (i.e., glass or polycarbonate). In the latter embodiment, each of the interlayer films may include a surface pattern, as described above, on one or both sides of the interlayer film. In a preferred embodiment, each of the interlayer films includes a surface pattern on both sides of the film.

[0021] In embodiments, the laminate has, after lamination, a relatively low haze and a relatively high light transmittance (as measured by ASTM D1003), making the laminate particularly suitable for applications requiring optical clarity. In one such embodiment, the haze of the laminate is about 0.8% to about 0.9%, or about 0.82% to about 0.86%, or about 0.84%. The light transmittance is about 85% to about 95%, or about 89% to about 90%.

[0022] A method for manufacturing an optical interlayer film is now described. An embossed pattern is engraved into a calender roll by standard techniques, such as mill engraving, etching (e.g., photo engraving), and / or mechanical engraving. In certain embodiments, the calender roll may comprise metal, rubber, or a combination thereof. In an exemplary embodiment, the calender roll comprises a metal roll and a rubber roll. The surface pattern is embossed into the metal roll, and the interlayer is passed through the rolls so that the metal roll faces one surface of the interlayer and the rubber roll faces the opposite surface. The optical intermediate layer was then passed through a roll to transfer this surface pattern to one surface of the intermediate layer film, such that the surface had at least two grooves extending in at least two non-parallel directions, the grooves having a depth of greater than about 20 μm. The surface pattern of the intermediate layer can include both peaks extending above the base surface and depressions extending below the base surface. In an embodiment, the method further includes transferring a second embossed pattern to a second surface of the interlayer film opposite the first surface. The second embossed pattern can be the same as or different from the first embossed pattern. In an exemplary embodiment, the second embossed pattern has at least two grooves extending in at least two non-parallel directions, the grooves having a depth greater than about 20 μm. The interlayer can be passed through a second calender roll having a metal roll that embosses the opposite surface of the interlayer. Alternatively, the interlayer can be flipped over so that the opposite surface faces the embossed metal roll. The method further includes placing the optical interlayer film between first and second sheets of rigid material (eg, glass) to obtain a laminate structure, and vacuum laminating the laminate structure. [Example]

[0023] Various sheets of TPU interlayer were manufactured by embossing a surface pattern. The surface pattern was first engraved into the surfaces of first and second calendar rolls. The calendar rolls included a metal roll and a rubber roll. The surface pattern was embossed into the metal roll. A thermoplastic polyurethane (TPU) material was passed through the rolls to transfer this surface pattern onto one surface of the interlayer. The surface pattern of the interlayer included both peaks extending above the base and depressions extending below the base. As shown in Table 2 below, rolls of six different intermediate layer materials were prepared (rolls 8-13), and the dimensions of the surface pattern of three different samples from each roll were measured. The average of these three different samples is shown in Table 2. As shown, the depth of each groove (roll average S t) was measured as the distance from the peak of each convex portion to the depth of each void adjacent to that convex portion. The average for the three samples on each roll was approximately 35.92 μm (roll 13) to approximately 41.02 μm (roll 8). The 85-degree gloss of the embossed surface of the interlayer (i.e., the side facing the metal roll) was about 15 to 17 (specifically, about 15.04 to about 16.71). In contrast, the 85-degree gloss of the opposite side of the interlayer (i.e., the side facing the rubber roll) was about 3.04 to about 3.82. Thus, the embossed surface pattern increased the 85-degree gloss of the interlayer by an average of about 12 to about 13. As shown in Table 2, the average gauge or thickness of the intermediate layer samples was about 0.015 inches. The minimum thickness was about 0.014 inches, and the maximum thickness was about 0.017 inches. [Table 2]

[0024] Figures 2 and 3 illustrate the line roughness of one of the rolls (roll 9). As indicated, a diagonal line was traced across the surface of the interlayer and height was measured along this diagonal line. The baseline or "zero μm" height was taken as the height at the bottom of each recess or void. As indicated, the total height or S of each groove was taken as the height at the bottom of each recess or void. t The distance between the peaks of each groove was about 600 μm to about 700 μm, and the width of each groove (measured at the midpoint of the groove height) was about 400 μm to about 600 μm. FIG. 4 shows the S t The overall frequency of values ​​is shown. As shown, the frequency roughly corresponds to a normal distribution curve (bell curve), with the mean or top of the curve being the S t is about 36 μm, and the width or standard deviation of the curve is about 12 μm (i.e., about 32 μm to 44 μm). The normal distribution curve has a few outliers, i.e., one intermediate layer is S t is approximately 30 μm, and five outliers are S t Although the S value exceeds 42 μm, all of the intermediate layers produced have an S value of at least 30 μm. t had.

[0025] The embossed interlayer material was then placed between two glass plates. The sandwich was then vacuum bagged using standard techniques, and the assembly was evacuated to about 28 inches (711 mm) of Hg absolute pressure for about 15 minutes. After this degassing step, the vacuum bagged assembly was simultaneously heated and pressed in an autoclave at a temperature of 239°F (115°C) and 100 psig (689,475.7 Pa) pressure for about 45 minutes. The laminate was held at these conditions for an additional 15 minutes to ensure the polymer melted and bonded to the glass substrate. At the end of this hold period, the laminate was removed from pressure and allowed to cool to ambient conditions to complete the lamination process. The resulting laminates were essentially clear or transparent with little or no haze. The haze of the resulting laminates was measured using ASTM D1003. As shown in Table 2, all laminates had a haze of 0.84%. The light transmittance of the resulting laminates was also measured using ASTM D1003. As shown in Table 2, all laminates had a light transmittance of 89.3. While the devices, systems, and methods have been described in detail in this disclosure according to certain preferred embodiments thereof, numerous modifications and variations may be implemented by those skilled in the art. Accordingly, the above description should not be construed as limited thereby, but should be construed to include such obvious variations as may be apparent, and should be limited only by the spirit and scope of the following claims.

[0026] For example, in a first aspect, a first embodiment is an optical interlayer film having at least one surface with an embossed surface pattern having at least two grooves extending in at least two non-parallel directions, the grooves having a depth greater than about 20 μm. The second embodiment is the first embodiment, in which the groove depth is greater than about 30 μm. The third embodiment is any combination of the first and second embodiments, in which the groove depth is about 30 μm to about 50 μm. The fourth embodiment is any combination of the first to third embodiments, in which the groove depth is about 35 μm to about 43 μm. The fifth embodiment is any combination of the first to fourth embodiments, in which the grooves have a width of about 30 μm to about 900 μm. A sixth embodiment is any combination of the first to fifth embodiments, wherein the grooves are formed from one or more protrusions extending from the surface and one or more recesses extending into the surface, and the distance between the peaks of the protrusions and the lowest points of the recesses is greater than about 20 μm. The seventh embodiment is any combination of the first to sixth embodiments, in which the grooves have a width of about 400 μm to about 600 μm. An eighth embodiment is any combination of the first through seventh embodiments, wherein the film comprises an unplasticized thermoplastic material. A ninth embodiment is any combination of the first to eighth embodiments, wherein the film comprises thermoplastic polyurethane (TPU). A tenth embodiment is any combination of the first through ninth embodiments, wherein the film comprises ethylene vinyl acetate (EVA). An eleventh embodiment is any combination of the first to tenth embodiments, further comprising a second surface opposite the first surface, the second surface having an embossed surface pattern with at least two grooves extending in at least two non-parallel directions, the grooves having a depth greater than about 20 μm. A twelfth embodiment is any combination of the first through eleventh embodiments, wherein the film has a thickness of less than about 0.08 inches. A thirteenth embodiment is any combination of the first through twelfth embodiments, wherein the film has a thickness of less than about 0.02 inches (0.508 mm). A fourteenth embodiment is any combination of the first to thirteenth embodiments, in which the two grooves are substantially perpendicular to each other. A fifteenth embodiment is any combination of the first to fourteenth embodiments, further comprising a first plurality of grooves extending in a first direction and a second plurality of grooves extending in a second direction non-parallel to the first direction, wherein the grooves within the first plurality of grooves are separated from one another by a distance of about 100 μm to about 1,000 μm.

[0027] In another aspect, there is provided a laminate comprising a film according to any combination of the first to fifteenth embodiments. In another aspect, there is provided a glass comprising a film according to any combination of the first to fifteenth embodiments. In another aspect, there is provided a window glazing comprising a film according to any combination of the first to fifteenth embodiments.

[0028] In another aspect, a first embodiment is a laminate including at least one glass layer and an interlayer film having at least one surface with an embossed surface pattern having at least two grooves extending in at least two non-parallel directions, the grooves having a depth greater than about 20 μm prior to lamination. The second embodiment is the first embodiment, in which the groove depth is greater than about 30 μm. The third embodiment is any combination of the first and second embodiments, in which the groove depth is about 30 μm to about 50 μm. The fourth embodiment is any combination of the first to third embodiments, in which the groove depth is about 35 μm to about 43 μm. A fifth embodiment is any combination of the first to fourth embodiments, wherein the laminate has a haze of about 0.8% to about 0.9% as measured by ASTM D1003. A sixth embodiment is any combination of the first through fifth embodiments, wherein the laminate has a light transmission of about 85% to about 90% as measured by ASTM D1003. A seventh embodiment is any combination of the first to sixth embodiments, further comprising a second glass layer, and the interlayer film is disposed between the first and second glass layers. An eighth embodiment is any combination of the first through seventh embodiments, wherein the film further comprises a second surface opposite the first surface, the second surface having an embossed surface pattern having at least two grooves extending in at least two non-parallel directions, the grooves having a depth greater than about 20 μm. A ninth embodiment is any combination of the first through eighth embodiments, wherein the film comprises an unplasticized thermoplastic material. A tenth embodiment is any combination of the first to ninth embodiments, wherein the film comprises thermoplastic polyurethane (TPU). An eleventh embodiment is any combination of the first through tenth embodiments, wherein the film comprises ethylene vinyl acetate (EVA). A twelfth embodiment is any combination of the first to eleventh embodiments, in which the two grooves are substantially perpendicular to each other. A thirteenth embodiment is any combination of the first to twelfth embodiments, further comprising a first plurality of grooves extending in a first direction and a second plurality of grooves extending in a second direction non-parallel to the first direction, wherein the grooves within the first plurality of grooves are separated from one another by a distance of about 100 μm to about 1,000 μm. A fourteenth embodiment is any combination of the first to thirteenth embodiments, wherein the laminate comprises a safety glass laminate. In another aspect, there is provided a glass comprising a laminate of any combination of the first to fourteenth embodiments. In another aspect, there is provided a window glazing comprising a laminate of any combination of the first to fourteenth embodiments.

[0029] In another aspect, a first embodiment is a method for making an interlayer film. The method includes forming an embossed pattern on a calender roll and transferring the embossed pattern onto a surface of the interlayer film, such that the surface has at least two grooves extending in at least two non-parallel directions. The grooves have a depth of greater than about 20 μm. A second embodiment is the first embodiment, wherein the interlayer film comprises a second surface opposite the first surface, and the method further comprises transferring the embossed pattern onto the second surface. A third embodiment is any combination of the first and second embodiments, further comprising the steps of placing an optical interlayer film between a first glass sheet and a second glass sheet to obtain a laminate structure, and vacuum laminating the laminate structure. The fourth embodiment is any combination of the first to third embodiments, in which the calender roll is a metal roll. A fifth embodiment is any combination of the first to fifth embodiments, wherein the grooves have a depth greater than about 30 μm. The sixth embodiment is any combination of the first to fifth embodiments, where the grooves have a depth of about 35 μm to about 43 μm. A seventh embodiment is any combination of the first through sixth embodiments, wherein the interlayer film comprises an unplasticized thermoplastic material. An eighth embodiment is any combination of the first to seventh embodiments, wherein the interlayer film comprises thermoplastic polyurethane (TPU). A ninth embodiment is any combination of the first to eighth embodiments, wherein the film comprises ethylene vinyl acetate (EVA). In another aspect, there is provided an interlayer film formed from any combination of the first through ninth embodiments. In another aspect, there is provided a laminate formed from any combination of the first to ninth embodiments. In another aspect, there is provided a window glazing formed from any combination of the first to ninth embodiments.

Claims

1. An optical interlayer film comprising at least one surface having an embossed surface pattern having at least two grooves extending in at least two non-parallel directions, said grooves having a depth greater than about 20 μm.

2. 10. The film of claim 1, wherein the grooves have a depth greater than about 30 μm.

3. 10. The film of claim 1, wherein the grooves have a depth of about 30 μm to about 50 μm.

4. 10. The film of claim 1, wherein the grooves have a depth of about 35 μm to about 43 μm.

5. The film of claim 1 , wherein the grooves have a width of from about 30 μm to about 900 μm.

6. 2. The film of claim 1, wherein the grooves are formed from one or more protrusions extending from the surface and one or more recesses extending into the surface, and the distance between the peaks of the protrusions and the lowest points of the recesses is greater than about 20 μm.

7. The film of claim 1 , wherein the grooves have a width of about 400 μm to about 600 μm.

8. The film of claim 1 , wherein the film comprises an unplasticized thermoplastic material.

9. The film of claim 1 , wherein the film comprises a thermoplastic polyurethane (TPU).

10. 10. The film of claim 1, wherein the film comprises ethylene vinyl acetate (EVA).

11. 10. The film of claim 1, further comprising a second surface opposite the first surface, the second surface having an embossed surface pattern having at least two grooves extending in at least two non-parallel directions, the grooves having a depth greater than about 20 μm.

12. 10. The film of claim 1, wherein the film has a thickness of less than about 0.08 inches.

13. 10. The film of claim 1, wherein the film has a thickness of less than about 0.02 inches.

14. The film of claim 1 , wherein the two grooves are substantially perpendicular to each other.

15. 10. The film of claim 1, further comprising a first plurality of grooves extending in a first direction and a second plurality of grooves extending in a second direction non-parallel to the first direction, wherein grooves within the first plurality of grooves are spaced apart from one another by a distance of about 100 μm to about 1,000 μm.

16. A laminate comprising the film of claim 1.

17. A glass comprising the film of claim 1.

18. Window glazing comprising the film of claim 1.

19. A laminate, at least one glass layer; an interlayer film having at least one surface with an embossed surface pattern having at least two grooves extending in at least two non-parallel directions, the grooves having a depth of greater than about 20 μm before lamination; A laminate comprising:

20. 20. The laminate of claim 19, wherein the grooves have a depth greater than about 30 μm.

21. 20. The laminate of claim 19, wherein the grooves have a depth of about 30 μm to about 50 μm.

22. 20. The laminate of claim 19, wherein the grooves have a depth of about 35 μm to about 43 μm.

23. 20. The laminate of claim 19, having a haze of about 0.8% to about 0.9% as measured by ASTM D1003.

24. 20. The laminate of claim 19, having a light transmission of about 85% to about 90% as measured by ASTM D1003.

25. 20. The laminate of claim 19, further comprising a second glass layer, the interlayer film disposed between the first and second glass layers.

26. 26. The laminate of claim 25, wherein the film further comprises a second surface opposite the first surface, the second surface having an embossed surface pattern having at least two grooves extending in at least two non-parallel directions, the grooves having a depth greater than about 20 μm.

27. 20. The laminate of claim 19, wherein the film comprises an unplasticized thermoplastic material.

28. 20. The laminate of claim 19, wherein the film comprises thermoplastic polyurethane (TPU).

29. 20. The laminate of claim 19, wherein the film comprises ethylene vinyl acetate (EVA).

30. 20. The laminate of claim 19, wherein the two grooves are substantially perpendicular to each other.

31. 20. The laminate of claim 19, further comprising a first plurality of grooves extending in a first direction and a second plurality of grooves extending in a second direction non-parallel to the first direction, wherein grooves within the first plurality of grooves are spaced apart from one another by a distance of about 100 μm to about 1,000 μm.

32. 20. The laminate of claim 19, wherein the laminate comprises a safety glass laminate.

33. A glass comprising the laminate of claim 19.

34. 20. A window glazing comprising the laminate of claim 19.

35. 1. A method for producing an intermediate layer film, comprising: forming an embossed pattern on a calender roll; transferring the embossed pattern onto a surface of an interlayer film, the surface having at least two grooves extending in at least two non-parallel directions, the grooves having a depth of greater than about 20 μm; A method comprising:

36. 36. The method of claim 35, wherein the interlayer film further comprises a second surface opposite the first surface, the method further comprising transferring the embossed pattern onto the second surface.

37. 36. The method of claim 35, further comprising the steps of: placing an optical interlayer film between a first glass sheet and a second glass sheet to obtain a laminate structure; and vacuum laminating the laminate structure.

38. 36. The method of claim 35, wherein the calender roll is a metal roll.

39. 36. The method of claim 35, wherein the grooves have a depth greater than about 30 μm.

40. 36. The method of claim 35, wherein the grooves have a depth of about 35 μm to about 43 μm.

41. 36. The method of claim 35, wherein the interlayer film comprises an unplasticized thermoplastic material.

42. 36. The method of claim 35, wherein the interlayer film comprises thermoplastic polyurethane (TPU).

43. 36. The method of claim 35, wherein the film comprises ethylene vinyl acetate (EVA).

44. 36. An interlayer film formed from the method of claim 35.

45. 36. A laminate formed from the method of claim 35.

46. 36. A window glazing formed from the method of claim 35.

Images