Multi-layer insulating glass units containing low CTE glass layers

Abstract

To provide an insulating glass unit with improved thermal and / or insulating properties that can also satisfy other design constraints, including reduced mass, thickness, and / or manufacturing costs. The present invention includes at least a first glass layer (10), a second glass layer (20), and a third glass layer (30) disposed therebetween. The third glass layer is separated from the first and second glass layers by first and second sealed gap intervals. The third glass layer has a lower CTE compared to the CTE of the first and / or second glass layers. In some cases, the third glass layer has a CTE of 70×10 over a temperature range of 0 to 300°C. -7 / °C and has a CTE of less than

Description

Description of Related Applications

[0001] This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Patent Application No. 62 / 609,069, filed December 21, 2017, the contents of which are incorporated herein by reference in their entirety. This application is a divisional application of Patent Application No. 2020-534250 filed on December 20, 2018, a divisional application of Patent Application No. 2023-177419 filed on October 13, 2023, and a divisional application of Patent Application No. 2025-77470 filed on May 7, 2025. [Technical Field]

[0002] The present disclosure relates generally to an insulated glass unit that includes at least one low CTE glass layer. More particularly, the present disclosure relates to a 70x10 insulated glass unit that can be used as a multi-pane window. -7 / °C. [Background technology]

[0003] Insulating glass units (IGUs) are useful as components in a wide variety of applications, including architecture, automobiles, displays, and appliances. IGUs may be used as multi-pane windows in buildings or automobiles to provide thermal insulation from external environmental temperatures. IGUs typically include two or more glass sheets sealed at their peripheral edges with a seal. The glass sheets are spaced apart, and the space between each glass sheet, once sealed, can be filled with an inert gas, such as argon or krypton, or an inert gas mixture. This can improve the insulating or thermal performance of the IGU. In addition to thermal and insulating performance, IGUs will typically need to meet other design constraints, including reduced mass, reduced thickness, improved light transmission, improved mechanical strength, and / or reduced manufacturing costs.

[0004] Triple IGUs (e.g., three panes of glass with two air cavities) exhibit improved thermal and insulating performance compared to double IGUs (e.g., two panes of glass with one air cavity), as indicated by 20-30% or more improvements in solar heat gain coefficient (SHGC) and / or insulation U-value. However, triple IGUs may not meet other design constraints, such as reduced mass, thickness, and / or manufacturing costs. The added mass, thickness, and / or manufacturing costs associated with the additional glass layers would adversely affect the IGU from meeting the design requirements of a particular application.

[0005] Additionally, because the center glass layer is insulated on both sides, it can reach much higher temperatures—and therefore higher stress levels—than the interior-facing and exterior-facing glass layers. To reduce the possibility of breakage, the center glass layer is often thermally tempered or heat-strengthened to improve its mechanical strength. However, the heat-strengthening process can require a thicker glass substrate, e.g., at least about 2–3 mm thick. As discussed above, a glass layer of this thickness can undesirably increase the overall thickness and / or mass of the IGU, and the additional tempering step can increase the manufacturing cost of the IGU. Furthermore, thermal tempering can warp and / or birefringence in the center glass layer, thereby reducing the optical quality of the IGU. Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, it would be advantageous to provide an IGU with improved thermal and / or insulating properties that can also satisfy other design constraints, including, but not limited to, reduced mass, thickness, and / or manufacturing costs. [Means for solving the problem]

[0007] The present disclosure, in various embodiments, provides an insulated glass unit including a first glass layer, a second glass layer, and a third glass layer disposed between the first and second glass layers, a first sealed gap distance defined between the first and third glass layers, and a second sealed gap distance defined between the second and third glass layers, wherein the third glass layer is 70×10 -7 The present invention relates to an insulating glass unit having a coefficient of thermal expansion (CTE) of less than 1 / °C over the temperature range 0-300°C.

[0008] The present disclosure also relates to an insulated glass unit including a first glass layer having a coefficient of thermal expansion CTE1, a second glass layer having a coefficient of thermal expansion CTE2, and a third glass layer disposed between the first and second glass layers and having a coefficient of thermal expansion CTE3, a first sealed gap spacing defined between the first and third glass layers, and a second sealed gap spacing defined between the second and third glass layers, wherein at least one of CTE1 > CTE3 or CTE2 > CTE3 holds true when measured over a temperature range of 0 to 300°C.

[0009] According to various embodiments, at least one of the first and second glass layers can have a thickness greater than about 2 mm. At least one of the first, second, and third glass layers can be chemically strengthened or thermally tempered. In certain embodiments, at least one of the inner surface of the first glass layer, the inner surface of the second glass layer, or a major surface of the third glass layer can be coated with at least one low-emissivity coating. According to further embodiments, at least one major surface of the third glass layer can be at least partially patterned with ink or light-scattering features. In still further embodiments, at least one insulating gas or a mixture thereof with air can be used to fill the first and / or second sealed gap intervals.

[0010] Insulated glass units disclosed herein may, in certain embodiments, include a fourth glass layer disposed between the first and second glass layers, and a third sealed gap defined between the third and fourth glass layers. In some embodiments, the fourth glass layer may be 70×10 -7 The third and / or fourth glass layers may have a coefficient of thermal expansion (CTE) of less than 1 / °C over the temperature range of 0-300°C. The third and / or fourth glass layers may be made from an aluminoborosilicate glass, such as an alkaline earth aluminoborosilicate glass or an alkali-free aluminoborosilicate glass, in various embodiments. According to a non-limiting embodiment, the third and / or fourth glass layers may be made from float-formed glass. The thickness of the third and / or fourth glass layers may be less than about 2 mm, or in alternative embodiments, greater than about 1.5 mm.

[0011] Additional features and advantages of the present disclosure will be set forth in the following detailed description, and in part will be readily apparent to those skilled in the art from that description, or may be learned by practicing the methods as described herein, including the following detailed description, claims, and accompanying drawings.

[0012] It will be understood that both the foregoing general description and the following detailed description, while illustrating various embodiments of the present disclosure, are intended to provide an overview or framework for understanding the nature and character of the claims. The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the present disclosure, and together with the description, serve to explain the principles and operation of the present disclosure.

[0013] The following detailed description can be better understood when read in conjunction with the following drawings. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view of a three-layer IGU according to an embodiment of the present disclosure. [Figure 2]1 is a cross-sectional view of a four-layer IGU according to an embodiment of the present disclosure. [Figure 3] 1 is a front view of an exemplary center glass layer of an IGU according to an embodiment of the present disclosure. [Figure 4] Diagram showing maximum principal stress in the center layer of EAGLE XG® glass in a 3-layer IGU at +60°C [Figure 5] Diagram showing deflection of the center layer of EAGLE XG glass in a three-ply IGU at -40°C DETAILED DESCRIPTION OF THE INVENTION

[0015] Various embodiments of the present disclosure will now be discussed with reference to Figures 1-5, which illustrate exemplary embodiments of IGUs and their components, features, or properties. The foregoing general description is intended to provide an overview of the claimed device; various aspects will be more specifically discussed throughout this disclosure in connection with the non-limiting illustrated embodiments, which are interchangeable within the context of this disclosure.

[0016] 1. An insulating glass unit including a first glass layer, a second glass layer, and a third glass layer disposed between the first and second glass layers, a first sealed gap distance defined between the first and third glass layers, and a second sealed gap distance defined between the second and third glass layers, wherein the third glass layer is 70×10 -7 Disclosed herein is an insulating glass unit having a coefficient of thermal expansion (CTE) of less than 1 / °C over the temperature range of 0-300°C.

[0017] Also disclosed herein is an insulating glass unit including a first glass layer having a coefficient of thermal expansion CTE1, a second glass layer having a coefficient of thermal expansion CTE2, and a third glass layer disposed between the first and second glass layers and having a coefficient of thermal expansion CTE3, a first sealed gap spacing defined between the first and third glass layers, and a second sealed gap spacing defined between the second and third glass layers, wherein at least one of CTE1>CTE3 or CTE2>CTE3 holds true when measured over a temperature range of 0-300°C.

[0018] An exemplary IGU 100 is shown in FIG. 1 and includes three glass layers 10, 20, and 30. The first (outer) glass layer 10 can be positioned with its exterior surface 12 facing the surrounding exterior environment. The second (inner) glass layer 20 can be positioned with its exterior surface 22 facing the interior, e.g., the interior of a building, automobile, or appliance. The third (center) glass layer 30 can be positioned between and spaced apart from the glass layers 10, 20. The third glass layer 30 can be positioned substantially parallel to the first and second glass layers 10, 20. All of the glass layers 10, 20, and 30 can be optically transparent, or one or more of the layers, or one or more portions thereof, can be translucent, opaque, or semi-opaque.

[0019] According to various embodiments, the first and second glass layers 10, 20 can be thicker than the third glass layer 30. In some embodiments, the glass layers 10, 20 can have a thickness ranging from about 2 mm to about 10 mm, such as from about 3 mm to about 8 mm, from about 4 mm to about 7 mm, or from about 5 mm to about 6 mm, including all ranges and subranges therebetween. In a non-limiting embodiment, the first and second glass layers 10, 20 can be made from soda-lime glass, although other glass types can be used, such as, without limitation, aluminosilicate and alkali aluminosilicate glasses, or other similar glasses. The coefficient of thermal expansion (CTE) of the first and / or second glass layers 10, 20, in various embodiments, can be greater than or equal to about 75×10, including all ranges and subranges therebetween. -7 > / ℃, approx. 80×10 -7 > / ℃, approx. 85×10 -7 > / ℃, approx. 90×10 -7 > / ℃, approx. 95×10 -7 / °C or about 10 x 10 -6 / ℃, etc., approximately 70 × 10 -7 / °C, e.g., greater than about 70 x 10 -7 / ℃ to approximately 15×10 -6 / ℃.

[0020] According to various embodiments, one or both of the first and second glass layers 10, 20 may be strengthened, for example, by thermal tempering, chemical strengthening, or other similar processes, to improve the mechanical strength of one or both of these layers. The first and second glass layers 10, 20 may, in some embodiments, be manufactured by a float or fusion draw manufacturing process.

[0021] In certain embodiments of the present disclosure, the inner surface 14 of the first glass layer 10 can be partially or fully coated with at least one first coating 16, such as a low-emissivity coating to improve thermal performance. Low-emissivity coatings are known in the art and may include, for example, without limitation, sputter-deposited pyrolytic coatings containing one or more metals and / or metal oxides, such as silver, titanium, and fluorine-doped tin oxide, to name a few. Alternatively, or in addition, the inner surface 24 of the second glass layer 20 can be partially or fully coated with at least one second coating 26. The first and second coatings 16 and 26 can be the same or different, depending on the desired properties and / or end use of the IGU. Combinations of coatings may also be used. In various embodiments, one or both of the coatings 16, 26 can be optically transparent.

[0022] In non-limiting embodiments, the third glass layer 30 can be thinner than the first and second glass layers 10, 20. In some embodiments, the third glass layer 30 can have a thickness of less than about 2 mm, such as from about 0.1 mm to about 1.5 mm, from about 0.3 mm to about 1.2 mm, from about 0.5 mm to about 1 mm, from about 0.6 mm to about 0.9 mm, or from about 0.7 mm to about 0.8 mm, including all ranges and subranges therebetween. According to further embodiments, the third glass layer 30 can have a thickness of greater than 1.5 mm, or even greater than 2 mm, such as from about 1.5 mm to about 4 mm, or from about 2 mm to about 3.5 mm, or from about 2.5 mm to about 3 mm, including all ranges and subranges therebetween.

[0023] In non-limiting embodiments, the third glass layer 30 can be made from an aluminoborosilicate glass, such as alkaline earth aluminoborosilicate glass, alkali-free aluminoborosilicate glass, or other similar glass types. Exemplary commercially available glass products include, but are not limited to, Corning® Willow®, EAGLE XG, and Lotus® glass. According to various embodiments, the third glass layer 30 can be strengthened, for example, by thermal tempering, chemical strengthening, or other similar processes, to improve the mechanical strength of this layer. The third glass layer 30 can, in some embodiments, be manufactured by a float or fusion draw manufacturing process.

[0024] According to various embodiments, the third glass layer 30 can have a lower CTE compared to the CTE of the first and / or second glass layers 10, 20. As used herein, CTE refers to the coefficient of thermal expansion of a specified glass layer measured over a temperature range of 0-300° C., e.g., at a temperature of about 20° C. In certain embodiments, the CTE of the third glass layer (CTE3) is less than about 60×10, including all ranges and subranges therebetween. -7 / ℃, approximately 50 × 10 -7 / ℃, approximately 45 × 10 -7 / ℃, approximately 40 × 10 -7 / ℃, approximately 35 × 10 -7 / ℃, approximately 30 × 10 -7 / °C or less, or about 25 x 10 -7 / ℃, etc., approximately 70 × 10 -7 / °C, e.g., about 10 x 10 -7 / ℃ to approximately 70×10 -7 / °C. In additional embodiments, the CTE of the first glass layer (CTE1) and / or the CTE of the second glass layer (CTE2) may be such that CTE1 > CTE3 and / or CTE2 > CTE3, or CTE1 ≥ 2. * CTE3 and / or CTE2 ≥ 2 * CTE3 or CTE1 ≥ 2.5 *CTE3 and / or CTE2 ≥ 2.5 * CTE3, or CTE1 ≥ 3 * CTE3 and / or CTE2 ≥ 3 * It can be larger than CTE3, such as CTE3.

[0025] Although not shown in FIG. 1 , one or both major surfaces of the third glass layer 30 may be partially or completely coated with at least one coating, such as the low-emissivity coatings described above with respect to coatings 16, 26. Alternatively, or in addition, one or both major surfaces of the third glass layer 30 may be partially or completely patterned with inks and / or surface features, e.g., decorative inks, light-scattering inks, and / or light-scattering surface features. Bulk scattering features located within the subsurface glass matrix may also be provided in the third glass layer 30, for example, by laser patterning. Surface scattering features may also be fabricated by laser patterning. When coatings and / or patterns are provided on both major surfaces of the third glass layer 30, these coatings and / or patterns can be the same or different, depending on the desired properties and / or end use of the IGU. Combinations of coatings and surface patterns may also be used. In additional embodiments, the third glass layer 30 may include at least one coating and at least one of an ink, a surface feature, and / or a bulk feature. Of course, the first and second glass layers 10, 20 may similarly be provided with such coatings, patterns, and / or features.

[0026] Referring again to FIG. 1 , the third glass layer 30 and the outer glass layer 10 can be spaced apart to define a first gap distance 15 therebetween, and the third glass layer 30 and the second glass layer 20 can be spaced apart to define a second gap distance 25 therebetween. Both gap distances 15, 25 can be sealed by sealant assemblies 18, 28, which can be the same or different. Exemplary sealant assemblies can be formed from a polymeric seal such as silicone rubber or other sealing material. The gap distances 15, 25 can be filled with an inert gas, which may further improve the thermal performance of the IGU. Suitable inert gases include, but are not limited to, argon, krypton, xenon, and combinations thereof. Mixtures of inert gases or mixtures of one or more inert gases with air can also be used. Exemplary, non-limiting inert gas mixtures include a 90 / 10 or 95 / 5 argon / air mixture, a 95 / 5 krypton / air mixture, or a 22 / 66 / 12 argon / krypton / air mixture. Other ratios of inert gas or inert gas to air may also be used depending on the desired thermal performance and / or end use of the IGU. According to various embodiments, the gases used to fill the gap intervals 15, 25 may be the same or different.

[0027] The gas pressures in the first gap interval 15 and the second gap interval 25 can be the same or different. The gas pressure difference may be due, for example, to the difference in average gas temperature in the two intervals; e.g., the gas in the first gap interval 15 may be warmer than the gas in the second gap interval 25, or vice versa, depending on the relative ambient and internal temperatures. The pressure difference between the two gap intervals 15, 25 may be sufficient to bend or curve the third glass layer 30, depending on its thickness. To prevent this, in some embodiments, the third glass layer 30 may be provided with at least one channel or opening to allow the gas in the gap interval 15 to contact the gas in the gap interval 25. The opening may be provided, for example, by drilling one or more orifices or holes in the third glass layer 30.

[0028] Alternatively, as shown in FIG. 3 , one or more corners of the third glass layer 30 may be cut or cut out, for example, by mechanical scoring and splitting or laser cutting. Thus, the peripheral shape of the third glass layer 30 may be altered to reduce the likelihood of the glass layer chipping and / or cracking. When the third glass layer 30 is sealed within the IGU, the cut corners 55 can provide channels through which gases from the gap intervals 15, 25 can pass and contact each other. This contact can eliminate or reduce the pressure differential between the two gap intervals, thereby reducing or eliminating curvature of the third glass layer 30.

[0029] Referring now to Figure 2, an alternative IGU 200 is shown that includes four glass layers 10, 20, 30, 40. The illustrated embodiment is similar to that of Figure 1, except that IGU 200 includes an additional fourth (central) glass layer 40. The central glass layers 30, 40 are disposed between the first and second glass layers 10, 20.

[0030] In non-limiting embodiments, the fourth glass layer 40 can be thinner than the first and second glass layers 10, 20. In some embodiments, the fourth glass layer 40 can have a thickness of less than about 2 mm, such as from about 0.1 mm to about 1.5 mm, from about 0.3 mm to about 1.2 mm, from about 0.5 mm to about 1 mm, from about 0.6 mm to about 0.9 mm, or from about 0.7 mm to about 0.8 mm, including all ranges and subranges therebetween. According to further embodiments, the fourth glass layer 40 can have a thickness greater than 1.5 mm, or even greater than 2 mm, such as from about 1.5 mm to about 4 mm, or from about 2 mm to about 3.5 mm, or from about 2.5 mm to about 3 mm, including all ranges and subranges therebetween. The thickness of the fourth glass layer 40 can be the same as or different from the thickness of the third glass layer 30.

[0031] In non-limiting embodiments, the fourth glass layer 40 can be made from an aluminoborosilicate glass, such as an alkaline-earth aluminoborosilicate glass, an alkali-free aluminoborosilicate glass, or other similar glass types. Exemplary commercially available glass products include, but are not limited to, Corning, Willow, EAGLE XG, and Lotus glass. According to various embodiments, the fourth glass layer 40 can be strengthened, for example, by thermal tempering, chemical strengthening, or other similar processes, to improve the mechanical strength of this layer. In some embodiments, the fourth glass layer 40 can be manufactured by a float or fusion draw manufacturing process. The composition of the fourth glass layer 40 can be the same as or different from the composition of the third glass layer 30. The mechanical properties of the fourth glass layer 40, such as the degree of strengthening, can also be the same as or different from the mechanical properties of the third glass layer 30.

[0032] According to various embodiments, the fourth glass layer 40 can have a lower CTE compared to the CTE of the first and / or second glass layers 10, 20. In certain embodiments, the CTE of the fourth glass layer (CTE4) is about 60×10, including all ranges and subranges therebetween.-7 / ℃, approximately 50 × 10 -7 / ℃, approximately 45 × 10 -7 / ℃, approximately 40 × 10 -7 / ℃, approximately 35 × 10 -7 / ℃, approximately 30 × 10 -7 / °C or less, or about 25 x 10 -7 / ℃, etc., approximately 70 × 10 -7 / °C, e.g., about 10 x 10 -7 / ℃ to approximately 70×10 -7 / °C. In additional embodiments, the CTE of the first glass layer (CTE1) and / or the CTE of the second glass layer (CTE2) may be such that CTE1 > CTE4 and / or CTE2 > CTE4, or CTE1 ≥ 2. * CTE4 and / or CTE2 ≥ 2 * CTE4, or CTE1 ≥ 2.5 * CTE4 and / or CTE2 ≥ 2.5 * CTE4, or CTE1 ≥ 3 * CTE4 and / or CTE2 ≥ 3 * CTE3 and CTE4 can be equal to or greater than CTE4, such as CTE4. CTE3 and CTE4 can be the same or different. According to a non-limiting embodiment, CTE3 is substantially equal to CTE4.

[0033] Although not shown in FIG. 2 , one or both major surfaces of the third and / or fourth glass layers 30 and 40 may be partially or completely coated with at least one coating, such as the low-emissivity coatings described above with respect to coatings 16, 26 (see FIG. 1 ). Alternatively, or in addition, one or both major surfaces of the third and / or fourth glass layers 30 and 40 may be partially or completely patterned with inks and / or surface features, e.g., decorative inks, light-scattering inks, and / or light-scattering surface features. Bulk scattering features located within the subsurface glass matrix may also be provided within the third and / or fourth glass layers 30, 40, for example, by laser patterning. Surface scattering features may also be fabricated using laser patterning. The coatings and / or surface patterns on one or both major surfaces of the third and / or fourth glass layers 30, 40 can be the same or different, depending on the desired properties and / or end use of the IGU. Combinations of coatings and surface patterns may also be used. In additional embodiments, the third and / or fourth glass layers 30, 40 may include at least one coating and at least one of an ink, a surface feature, and / or a bulk feature.

[0034] The third glass layer 30 and the outer glass layer 10 can be spaced apart to define a first gap spacing 15 therebetween, the third glass layer 30 and the fourth glass layer 40 can be spaced apart to define a third gap spacing 35 therebetween, and the fourth glass layer 40 and the inner glass layer 20 can be spaced apart to define a fourth gap spacing 45 therebetween. The gap spacings 15, 35, 45 can be sealed by sealant assemblies 18, 38, 48, which can be the same or different. Exemplary sealant assemblies are described above, and exemplary inert gases and inert gas mixtures for filling the gap spacings are disclosed above with reference to FIG. 1. According to various embodiments, the gases used to fill the gap spacings 15, 35, 45 can be the same or different. The fourth glass layer 40 can also include one or more cut corners (see FIG. 3).

[0035] 1-2 , the thickness of gap spacings 15, 25, 35, 45 can vary depending on the IGU structure, for example, from about 6 mm to about 18 mm, such as from about 7 mm to about 16 mm, from about 8 mm to about 14 mm, or from about 10 mm to about 12 mm, including all ranges and subranges therebetween. The thicknesses of gap spacings 15, 25 ( FIG. 1 ) or gap spacings 15, 35, 45 ( FIG. 2 ) can be the same or different. The overall thickness of IGU 100 can be about 40 mm or less, such as about 36 mm or less, about 32 mm or less, about 30 mm or less, about 28 mm or less, or about 26 mm or less, including all ranges and subranges therebetween. In some embodiments, a low U-value, representing improved thermal insulation properties, is achieved when the gap spacing thickness ranges from about 14 mm to about 16 mm and the overall thickness of IGU 100 ranges from about 36 mm to about 40 mm. The overall thickness of the IGU 200 can be about 60 mm or less, such as about 56 mm or less, about 54 mm or less, about 50 mm or less, about 40 mm or less, about 30 mm or less, or about 26 mm or less, including all ranges and subranges therebetween. In some embodiments, a low U-value, representing improved thermal insulation properties, is achieved when the gap spacing thickness ranges from about 16 mm to about 18 mm and the overall thickness of the IGU 200 ranges from about 54 mm to about 60 mm.

[0036] It should be noted that while the glass layers in Figures 1-3 are referred to herein as single glass sheets, the claims appended hereto should not be so limited, as they may include glass laminate structures, including glass-polymer laminate structures or glass-glass laminate structures. Suitable glass-polymer laminate structures include a single sheet of glass laminated to a polymer film, two glass sheets with an intermediate polymer film, etc. Suitable glass-glass laminate structures include structures having an inner glass core and one or two outer glass cladding layers. In some embodiments, the laminate may include two or more glass layers, such as three or more glass layers, where the glass layers are selected from alkaline earth aluminoborosilicate glass, alkali-free aluminoborosilicate glass, and soda-lime glass. Exemplary glass-glass laminate structures and methods for making them are described in commonly owned U.S. Pat. No. 8,007,913, U.S. Patent Application Publication Nos. 2013 / 0015180 and 2013 / 312459, and WO 14 / 018838, all of which are incorporated herein by reference.

[0037] The IGUs disclosed herein may be used in a variety of applications, including windows, doors, and skylights in buildings and other architectural applications, windows in automotive and other vehicle applications, windows or display panels in appliances, and display panels in electronic devices, to name a few. According to various embodiments, one or more LEDs may be optically coupled to at least one edge of the IGU to provide illumination across one or more regions of the IGU. Edge lighting can provide, for example, sunlight-like illumination, which may be useful in various architectural and automotive applications, such as skylights and sunroofs. As previously mentioned, one or more glass layers in the IGU can be provided with bulk or surface light-scattering features, which can promote uniformity of light transmitted through the IGU. In some embodiments, low-CTE glass may be more easily laser machined to provide such light-scattering features than higher-CTE glass, which may crack or develop other defects during laser patterning.

[0038] In various non-limiting embodiments, the use of a low-CTE glass for the central glass layer, e.g., the third and / or fourth glass layers, can provide several advantages over conventional IGUs. For example, a low-CTE central glass layer may have improved resistance to thermal stresses and / or breakage caused by temperature gradients across the IGU. Therefore, manufacturing costs may be reduced by eliminating a thermal tempering step that would otherwise be used to strengthen a central glass layer made from a conventional glass with a higher CTE, such as soda-lime glass.

[0039] Because thermal tempering of the central glass layer can be avoided, the optical performance of the IGU may be improved due to, for example, the absence of distortion or birefringence caused by such a processing step. The absence of a thermal tempering step may also allow for a thinner central glass layer, resulting in a reduction in the overall thickness and / or mass of the IGU. The reduction in IGU mass may result in cost savings during manufacturing, transportation, installation, maintenance, and / or operation. The reduction in IGU thickness may expand the range of applications for the IGU that would otherwise be limited by design constraints.

[0040] A thinner, low-CTE central layer also allows for a wider sealing gap between the glass layers. A larger volume of insulating gas in the sealing gap can improve the energy efficiency of the IGU. An IGU with a narrow sealing gap will be more susceptible to bowing due to gas contraction within the gap. The bowing can result in contact between the outer and central glass layers. Such contact is cosmetically undesirable and also allows for direct heat transfer between the glass layers, which is unacceptable from an energy standpoint. Using a thinner, low-CTE central glass layer allows for a wider gap, thus reducing the potential for bowing and / or contact between the glass layers.

[0041] Thermal stresses that result in glass failure in an IGU can be caused, for example, by a sudden temperature change in one region of the IGU relative to another region of the IGU. For example, a sudden increase in the external (ambient) temperature compared to the internal temperature, or vice versa, can cause thermal stress in one or more regions of the IGU. On a cold morning, sunlight entering a window can rapidly increase the temperature of the exposed region of the IGU, while the surrounding area of ​​the IGU, for example, located under the window frame, remains cool. Finite element analysis (FEA) modeling indicates that thermal stresses induced in the center glass layer can reach a temperature difference of approximately 0.62 MPa / °C for conventional soda-lime glass. Under summer conditions (e.g., approximately 28°C), the center glass layer can reach a temperature as high as 60°C, creating a temperature difference as large as 40°C between the center glass layer and the outer glass layers. Therefore, thermal stresses induced in a center layer made from soda-lime glass can be approximately 25 MPa or greater.

[0042] Soda lime glass is approximately 90 x 10 -7 / °C. In comparison, Corning EAGLE XG glass has a CTE of 31.7 x 10, which is about one-third the CTE of soda-lime glass. -7 / °C. Under the same 40°C temperature gradient described above, a central layer made from "EAGLE XG" glass would experience a thermal stress of only 8.7 MPa, resulting in a low risk of fracture even without thermal tempering or chemical strengthening.

[0043] A model was developed to evaluate the use of low-CTE glass as a central glass layer between two higher-CTE glass layers in an IGU. The model was a three-layer IGU (length = 1265 mm, width = 989 mm) with an outer glass layer (thickness = 4 mm) made from soda-lime glass, an inner glass layer (thickness = 6 mm) made from soda-lime glass, and a central glass layer (thickness = 0.7 mm) made from "EAGLE XG" glass. The gap between the central glass layer and the inner and outer glass layers was 12 mm wide, filled with argon gas, and sealed with a silicone rubber perimeter seal.

[0044] Referring to Figure 4, the tensile stress on the EAGLE XG center glass layer was modeled at +60°C to simulate expansion of the soda-lime glass layer due to high temperatures. Figure 5 shows the compressive stress on the EAGLE XG center glass layer at -40°C to simulate contraction of the soda-lime glass layer due to low temperatures. Figure 4 shows that the maximum principal stress on the EAGLE XG center glass layer at +60°C is less than 1 MPa, and Figure 5 shows that the deflection of the EAGLE XG center glass layer is less than 1 mm, indicating that the modeled IGU adequately resists fracture, distortion, and / or buckling due to thermal stresses induced by both high and low temperature gradients.

[0045] It will be recognized that various disclosed embodiments may include specific features, elements, or steps that are described with respect to a particular embodiment. It will also be recognized that specific features, elements, or steps, although described with respect to one particular embodiment, may be interchanged or combined in alternative embodiments in various non-illustrated combinations or orders.

[0046] It will also be understood that nouns refer to "at least one" of an object and should not be limited to "only one" unless expressly indicated to the contrary. Thus, for example, reference to an "element" includes instances having one such "element" or two or more such "elements" unless the context clearly indicates otherwise. Similarly, the words "plurality" or "series" are intended to indicate two or more, and thus a "series of elements" or "plurality of elements" refers to two or more of such elements.

[0047] Ranges may be expressed herein as from "about" one particular value, and / or to "about" another particular value. When such a range is expressed, examples include from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0048] All numerical values ​​expressed herein should be construed to include "about," whether or not so stated, unless expressly indicated otherwise. However, it will be further understood that each recited numerical value is considered to be exactly the same, whether or not it is expressed as "about" that value. Thus, both "less than 100 nm in size" and "less than about 100 nm in size" include the embodiments of "less than about 100 nm in size" as well as "less than 100 nm in size."

[0049] Unless expressly stated otherwise, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a particular order. Thus, unless a method claim actually recites the order in which its steps should be followed, or unless it is otherwise specifically stated in the claim or description that the steps should be limited to a particular order, no particular order is intended to be implied in any way.

[0050] Although various features, elements, or steps of particular embodiments may be disclosed using the transitional phrase "comprising," it will be understood that alternative embodiments are implied, including embodiments that may be described using the transitional phrases "consisting of" or "consisting essentially of." Thus, for example, alternative embodiments implied by a device comprising A+B+C include embodiments in which the device consists of A+B+C, and embodiments in which the device consists essentially of A+B+C.

[0051] It will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the spirit and scope of the present disclosure. Since modifications, combinations, subcombinations, and variations of the disclosed embodiments that encompass the spirit and substance of the present disclosure will occur to those skilled in the art, the present disclosure should be considered to include all within the scope of the appended claims and equivalents thereof.

[0052] Preferred embodiments of the present invention will be described below in detail.

[0053] Embodiment 1 a first glass layer; a second glass layer, a third glass layer disposed between the first and second glass layers; a first sealed gap distance defined between the first glass layer and the third glass layer; and a second sealed gap distance defined between the second glass layer and the third glass layer; 1. An insulating glass unit comprising: The third glass layer is 70×10 -7 1. An insulating glass unit having a coefficient of thermal expansion (CTE) of less than 1 / °C over the temperature range 0-300°C, and a thickness of about 0.3 mm to about 1.2 mm.

[0054] Embodiment 2 10. The insulated glass unit of claim 1, wherein the third glass layer is made from an aluminoborosilicate glass.

[0055] Embodiment 3 3. The insulated glass unit of embodiment 2, wherein the third glass layer is made from alkaline earth aluminoborosilicate glass or alkali-free aluminoborosilicate glass.

[0056] Embodiment 4 10. The insulated glass unit of claim 1, wherein the third glass layer is made from float-formed glass.

[0057] Embodiment 5 10. The insulated glass unit of claim 1, wherein the third glass layer has a thickness of about 0.5 mm to about 1 mm.

[0058] Embodiment 6 10. The insulated glass unit of claim 1, wherein the third glass layer has a thickness of about 0.6 mm to about 0.9 mm.

[0059] Embodiment 7 10. The insulated glass unit of claim 1, wherein at least one of the first and second glass layers has a thickness greater than about 2 mm.

[0060] Embodiment 8 10. The insulated glass unit of embodiment 1, wherein at least one of the first, second, and third glass layers is chemically strengthened or thermally tempered.

[0061] Embodiment 9 10. The insulated glass unit of claim 1, wherein at least one of the first, second, and third glass layers is a glass laminate.

[0062] Embodiment 10 10. The insulated glass unit of claim 1, wherein at least one of the inner surface of the first glass layer, the inner surface of the second glass layer, or the major surface of the third glass layer is coated with at least one low-emissivity coating.

[0063] Embodiment 11 10. The insulated glass unit of embodiment 1, wherein at least one major surface of the third glass layer is at least partially patterned with ink or light scattering features.

[0064] Embodiment 12 10. The insulating glass unit of embodiment 1, wherein at least one of the first and second sealing gap intervals is filled with at least one insulating gas or a mixture thereof with air.

[0065] Embodiment 13 10. The insulated glass unit of claim 1, further comprising a fourth glass layer disposed between the first glass layer and the second glass layer, and a third sealed gap interval defined between the third glass layer and the fourth glass layer.

[0066] Embodiment 14 The fourth glass layer is 70×10 -7 14. The insulating glass unit of embodiment 13, having a coefficient of thermal expansion (CTE) of less than 1 / °C over the temperature range of 0-300°C, and a thickness of about 0.3 mm to about 1.2 mm.

[0067] Embodiment 15 15. The insulated glass unit of claim 14, wherein the fourth glass layer is made from an aluminoborosilicate glass.

[0068] Embodiment 16 15. The insulated glass unit of claim 14, wherein the fourth glass layer has a thickness of about 0.5 mm to about 1 mm.

[0069] Embodiment 17 a first glass layer having a coefficient of thermal expansion CTE1; a second glass layer having a coefficient of thermal expansion CTE2; a third glass layer disposed between the first and second glass layers and having a coefficient of thermal expansion CTE3; a first sealed gap distance defined between the first glass layer and the third glass layer; and a second sealed gap distance defined between the second glass layer and the third glass layer; 1. An insulating glass unit comprising: An insulating glass unit in which, when measured over a temperature range of 0 to 300°C, at least one of CTE1 > CTE3 or CTE2 > CTE3 holds true.

[0070] Embodiment 18 18. The insulated glass unit of claim 17, further comprising a fourth glass layer disposed between the first glass layer and the second glass layer, and a third sealed gap defined between the third glass layer and the fourth glass layer, the fourth glass layer having a coefficient of thermal expansion CTE4.

[0071] Embodiment 19 At least one of CTE3 and CTE4 over the temperature range of 0 to 300°C is 70 × 10 -7 19. The insulated glass unit of embodiment 17 or 18, wherein the thermal expansion coefficient is less than 1 / °C.

[0072] Embodiment 20 19. The insulated glass unit of claim 17 or 18, wherein at least one of the third and fourth glass layers is made from an aluminoborosilicate glass.

[0073] Embodiment 21 19. The insulated glass unit of claim 17 or 18, wherein at least one of the third and fourth glass layers has a thickness of from about 0.3 mm to about 1.2 mm.

[0074] Embodiment 22 a first glass layer having a coefficient of thermal expansion CTE1; a second glass layer having a coefficient of thermal expansion CTE2; a third glass layer disposed between the first and second glass layers and having a coefficient of thermal expansion CTE3; a first sealed gap distance defined between the first glass layer and the third glass layer; and a second sealed gap distance defined between the second glass layer and the third glass layer; 1. An insulating glass unit comprising: When measured over a temperature range of 0 to 300°C, at least one of CTE1>CTE3 or CTE2>CTE3 is satisfied, The third glass layer is 70×10 -7 Insulated glass units with a CTE of less than 3 / °C and a thickness of 0.3mm to 1.2mm. Embodiment 23 23. The insulated glass unit of claim 22, wherein the third glass layer comprises an aluminoborosilicate glass, an alkaline earth aluminoborosilicate glass, or an alkali-free aluminoborosilicate glass. Embodiment 24 23. The insulated glass unit of claim 22, wherein the third glass layer has a thickness of about 0.5 mm to about 1 mm. Embodiment 25 23. The insulated glass unit of claim 22, wherein the third glass layer has a thickness of about 0.6 mm to about 0.9 mm. Embodiment 26 23. The insulated glass unit of claim 22, wherein at least one of the first and second glass layers has a thickness greater than about 2 mm. Embodiment 27 23. The insulated glass unit of claim 22, wherein at least one of the first and second glass layers has a thickness of 4 mm to 7 mm. Embodiment 28 23. The insulated glass unit of claim 22, wherein at least one of the first, second, and third glass layers is chemically strengthened or thermally tempered. Embodiment 29 23. The insulated glass unit of claim 22, wherein at least one of the first, second, and third glass layers is a glass laminate. Embodiment 30 23. The insulated glass unit of claim 22, wherein at least one of the inner surface of the first glass layer, the inner surface of the second glass layer, or the major surface of the third glass layer is coated with at least one low-emissivity coating. Embodiment 31 23. The insulating glass unit of embodiment 22, wherein at least one of the first and second sealing gap intervals is filled with at least one insulating gas or a mixture thereof with air. Embodiment 32 a first glass layer comprising soda-lime glass, having a coefficient of thermal expansion CTE1, and having a thickness of about 2 mm to about 10 mm; a second glass layer comprising soda-lime glass, having a coefficient of thermal expansion CTE2, and having a thickness of about 2 mm to about 10 mm; a third glass layer disposed between the first and second glass layers, the third glass layer comprising an aluminoborosilicate glass and having a coefficient of thermal expansion CTE3; a first sealed gap distance defined between the first glass layer and the third glass layer; and a second sealed gap distance defined between the second glass layer and the third glass layer; 1. An insulating glass unit comprising: Measurements were taken over the temperature range of 0 to 300°C, and CTE1>CTE3 and CTE2>CTE3 were observed. The third glass layer is 33×10 -7 / °C and has a CTE of less than 3 and a thickness of 0.4 mm to 0.9 mm. The third glass layer exhibits a maximum principal stress of less than 1 MPa when the insulating glass unit is at an elevated temperature of 60°C, the insulating glass unit being assembled at an assembly temperature of 20°C at which the third glass layer exhibits zero stress, the first glass layer having a reference thickness of 4 mm, the second glass layer having a reference thickness of 6 mm, and the third glass layer having a reference thickness of 0.7 mm, a reference width of 989 mm, and a reference length of 1265 mm. Embodiment 33 33. The insulated glass unit of claim 32, wherein the third glass layer comprises an alkaline earth aluminoborosilicate glass or an alkali-free aluminoborosilicate glass. Embodiment 34 33. The insulated glass unit of claim 32, wherein the third glass layer has a thickness of about 0.5 mm to about 0.9 mm. Embodiment 35 33. The insulated glass unit of claim 32, wherein the third glass layer has a thickness of about 0.5 mm to about 0.7 mm. Embodiment 36 33. The insulated glass unit of claim 32, wherein at least one of the first and second glass layers has a thickness greater than about 2 mm. Embodiment 37 33. The insulated glass unit of claim 32, wherein at least one of the first and second glass layers has a thickness of 3 mm to 8 mm. Embodiment 38 33. The insulated glass unit of claim 32, wherein at least one of the first, second, and third glass layers is chemically strengthened or thermally tempered. Embodiment 39 33. The insulated glass unit of claim 32, wherein at least one of the inner surface of the first glass layer, the inner surface of the second glass layer, or the major surface of the third glass layer is coated with at least one low-emissivity coating. Embodiment 40 33. The insulated glass unit of embodiment 32, wherein at least one of the first and second sealing gap intervals is filled with at least one insulating gas or a mixture of the at least one insulating gas and air. Embodiment 41 a first glass layer having a first outer surface facing an exterior environment and a first inner surface facing opposite the first outer surface, the first glass layer comprising soda-lime glass and having a thickness of about 75×10 -7 a first glass layer having a coefficient of thermal expansion CTE1 of greater than 1 / °C and a thickness of about 2 mm to about 4 mm; a second glass layer having a second outer surface facing the interior environment and a second inner surface facing opposite the second outer surface, the second glass layer comprising soda-lime glass and having a thickness of about 75×10 -7 a second glass layer having a coefficient of thermal expansion CTE2 of greater than 1 / °C and a thickness of about 2 mm to about 4 mm; a 33×10 -7 a third glass layer having a coefficient of thermal expansion CTE of less than 3 / °C and a thickness of 0.4 mm to 0.9 mm; a first sealed gap distance defined between the first glass layer and the third glass layer; a second sealed gap distance defined between the second glass layer and the third glass layer; and one or more of the inner surface of the first glass layer and the inner surface of the second glass layer coated with at least one low-emissivity coating; 1. An insulating glass unit comprising: Measurements over the temperature range of 0 to 300°C show that CTE1>2.5xCTE3 and CTE2>2.5xCTE3. The third glass layer exhibits a maximum principal stress of less than 1 MPa when the insulating glass unit is at an elevated temperature of 60°C, the insulating glass unit being assembled at an assembly temperature of 20°C at which the third glass layer exhibits zero stress, the first glass layer having a reference thickness of 4 mm, the second glass layer having a reference thickness of 6 mm, and the third glass layer having a reference thickness of 0.7 mm, a reference width of 989 mm, and a reference length of 1265 mm. [Explanation of symbols]

[0075] 10 First Glass Layer 15 First gap distance 16 First Coating 18, 28, 38, 48 Sealant Assembly 20 Second Glass Layer 25 Second Gap Distance 26 Second Coating 30 Third Glass Layer 35 Third Gap Distance 40 Fourth Glass Layer 45 fourth gap interval 55 Cut corner 100, 200 IGU

Claims

1. a first glass layer; a second glass layer; a third glass layer disposed between the first glass layer and the second glass layer; a first sealing gap distance defined between the first glass layer and the third glass layer; and a second sealing gap distance defined between the second and third glass layers; 1. An insulating glass unit comprising: The third glass layer has a temperature range of 0°C to 300°C and a thermal conductivity of 70 x 10 －７ 1. An insulating glass unit having a coefficient of thermal expansion (CTE) of less than 1 / °C and a thickness of 0.3 mm to 0.9 mm.

2. The insulated glass unit of claim 1 , wherein the third glass layer comprises an aluminoborosilicate glass.

3. The insulated glass unit of claim 2 wherein the third glass layer comprises an alkaline earth aluminoborosilicate glass or an alkali-free aluminoborosilicate glass.

4. The insulated glass unit of claim 1 , wherein the third glass layer comprises float-formed glass.

5. The insulated glass unit of claim 1 , wherein the third glass layer has a thickness of from 0.5 mm to 0.9 mm.

6. The insulated glass unit of claim 1 , wherein the third glass layer has a thickness of from 0.6 mm to 0.9 mm.

7. The insulated glass unit of claim 1 , wherein at least one of the first and second glass layers has a thickness greater than 2 mm.

8. The insulated glass unit of claim 1 , wherein at least one of the first glass layer, the second glass layer, and the third glass layer is chemically strengthened or thermally tempered.

9. The insulated glass unit of claim 1 , wherein at least one of the first glass layer, the second glass layer, and the third glass layer is a glass laminate.

10. 10. The insulated glass unit of claim 1, wherein at least one of the inner surface of the first glass layer, the inner surface of the second glass layer, or the major surface of the third glass layer is coated with at least one low-emissivity coating.

11. The insulated glass unit of claim 1 , wherein at least one major surface of the third glass layer is at least partially patterned with ink or light scattering features.

12. 10. The insulated glass unit of claim 1, wherein at least one of the first sealed gap interval and the second sealed gap interval is filled with at least one insulating gas or a mixture of the at least one insulating gas and air.

13. 10. The insulated glass unit of claim 1, further comprising a fourth glass layer disposed between the first glass layer and the second glass layer, and a third sealed gap interval defined between the third glass layer and the fourth glass layer.

14. The fourth glass layer has a temperature range of 0°C to 300°C and a thermal conductivity of 70 x 10 －７ 14. The insulated glass unit of claim 13, having a coefficient of thermal expansion (CTE) of less than 1 / °C and a thickness of 0.3 mm to 1.2 mm.

15. The insulated glass unit of claim 14 wherein the fourth glass layer comprises an aluminoborosilicate glass.

16. 15. The insulated glass unit of claim 14, wherein the fourth glass layer has a thickness of 0.5 mm to 1 mm.

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