Laminated glass articles with continuously curved edge profiles

Abstract

Described are laminated glass that include a first glass substrate comprising a first thickness extending between a first major surface and a second major surface, a second glass substrate comprising a second thickness extending between a third major surface and a fourth major surface, and a polymer interlayer disposed between and joining with the second major surface and the third major surface. The first thickness is greater than the second thickness, while both the first thickness and the second thickness are greater than or equal to 0.5 mm The second glass substrate is strengthened to a greater extent than the first glass substrate. A composite edge surface of the laminated glass article extends from the first major surface to the fourth major surface and defines an arc between the first major surface and the fourth major surface with a continuous curvature.

Description

LAMINATED GLASS ARTICLES WITH CONTINUOUSLY CURVED EDGE PROFILESCROSS-REFERENCE TO RELATED PPLICATIONS

[0001] This application claims the benefit of priority of U.S. Provisional Application Serial No. 63 / 528,510, filed on July 24, 2023, the content of which is relied upon and incorporated herein by reference in its entirety.FIELD

[0002] The present disclosure relates to laminated glass articles, and in particular, laminated glass articles with edge profiles that produce less abrasion on vehicle weather seals than conventional edge profiles.BACKGROUND

[0003] Laminated automotive door glass applications are gaining in popularity. Laminates offer significant sound insulation compared to monolithic tempered safety glass. Typically, these laminates are made with two glass substrates of equal thicknesses and each substrate has a bullnose edge. This results in two distinct radii (e.g., a bullnose or C-shaped edge profile) with the interlayer disposed between them. When the door glass window is raised or lowered, the edge of this laminate is viewable and not aesthetically pleasing. Additionally, because the glass substrates used in such laminates tend to be thinner than traditional monolithic thermally tempered windows, the thin glass substrate in contact with the seal material used to provide a weather seal the glass substrate rubs against can contribute to excessive wear of the seal material.SUMMARY

[0004] Disclosed herein are laminated glass articles suitable for installation in applications such as vehicle side windows (e.g., door windows, sun or moon roofs), wherein the laminated glass article is subject to repeated rubbing against a polymer material, for example a polymer weather seal. The laminated glass article comprises a composite edge surface that may be aesthetically pleasing, can exhibit reduced friction against the seal material, thereby prolonging the life of the seal material, while also providing improved edge impact performance.

[0005] An aspect (1) of the present disclosure pertains to a laminated glass article, comprising: a first glass substrate comprising a first major surface, a second major surface opposite the first major surface, a first edge surface joining the first major surface and the second major surface, and a first thickness extending between the first major surface and the second major surface; asecond glass substrate comprising a third major surface, a fourth major surface opposite the third major surface, a second edge surface joining the third major surface and the second major surface, and a second thickness extending between the third major surface and the fourth major surface; and a polymer interlayer disposed between and joining with the second major surface and the third major surface, the polymer interlayer comprising an interlayer edge surface, wherein: the first thickness is greater than the second thickness, both the first thickness and the second thickness are greater than or equal to 0.5 mm, the second glass substrate comprises a maximum tensile stress that is greater than that of the first glass substrate as a result of being strengthened to a greater extent than the first glass substrate, and wherein a composite edge surface of the laminated glass article extends from the first major surface to the fourth major surface and includes the first edge surface, the second edge surface, and the interlayer edge surface, the composite edge surface defining an arc between the first major surface and the fourth major surface with a continuous curvature.

[0006] An aspect (2) of the present disclosure pertains to a laminated glass article according to the aspect (1), wherein the arc comprises no inflection points.

[0007] An aspect (3) of the present disclosure pertains to a laminated glass article according to the aspect (2), wherein the arc comprises a constant radius of curvature such that the arc is a circular arc.

[0008] An aspect (4) of the present disclosure pertains to a laminated glass article according to the aspect (3), wherein: the arc comprises a center of curvature disposed within the first glass substrate or on the first major surface, and an entirety of the composite edge is disposed on the arc.

[0009] An aspect (5) of the present disclosure pertains to a laminated glass article according to any of the aspects ( l)-(4), wherein the arc comprises a minimum radius of curvature that is greater than or equal to a quarter of a total thickness of the laminated glass article.

[0010] An aspect (6) of the present disclosure pertains to a laminated glass article according to the aspect (5), wherein the minimum radius of curvature is greater than or equal to 1.0 mm.

[0011] An aspect (7) of the present disclosure pertains to a laminated glass article according to any of the aspects (5)-(6), wherein: the first thickness is greater than or equal to 2.5 mm and less than or equal to 6.0 mm, the second thickness is greater than or equal to 0.5 mm and less than or equal to 0.7 mm, and the interlayer comprises a thickness that is greater than or equal to 0.3 mm.

[0012] An aspect (8) of the present disclosure pertains to a laminated glass article according to any of the aspects ( 1 )-(7), where the interlayer has a modulus of elasticity ranging from 1 MPa to 75 MP.

[0013] An aspect (9) of the present disclosure pertains to a laminated glass article according to the aspect (1), wherein the interlayer comprises a central portion comprising a peripheral edge and a peripheral portion extending outward from the peripheral edge, the peripheral portion contacting the first glass substrate and the second glass substrate and forming a portion of the composite edge surface.

[0014] An aspect (10) of the present disclosure pertains to a laminated glass article according to the aspect (9), wherein a modulus of elasticity of the peripheral portion is greater than a modulus of elasticity of the central portion.

[0015] An aspect (11) of the present disclosure pertains to a laminated glass article according to the aspect (1), wherein the composite edge surface is coated with a perfluoropolyether coating or a polymer coating with a molecular weight greater than about 106grams / mole.

[0016] An aspect (12) of the present disclosure pertains to a laminated glass article according to the aspect (1), wherein, when an edge of the fourth major surface is impacted with a 144 g gram cylindrical stainless steel weight at an impact angle of 30° with an impact energy of 0.3 J, the second glass substrate does not fracture from the impact.

[0017] An aspect (13) of the present disclosure pertains to a laminated glass article according to the aspect (12), wherein: the second thickness is greater than or equal to 0.9 mm and less than or equal to 1.5 mm and the second glass substrate is chemically strengthened such that the fourth major surface comprises a surface compressive stress greater than or equal to 600 MPa, and when the weight impacts the edge of the fourth major surface with an impact energy of 0.6 J, the second glass substrate does not break from the impact.

[0018] An aspect (14) of the present disclosure pertains to a laminated glass article according to the aspect (12), wherein: the second thickness is greater than or equal to 1.1 mm and less than or equal to 1.5 mm and the second glass substrate is chemically strengthened such that the fourth major surface comprises a surface compressive stress greater than or equal to 600 MPa, and when the weight impacts the edge of the fourth major surface with an impact energy of 0.75 J, the second glass substrate does not break from the impact.

[0019] An aspect (15) of the present disclosure pertains to a laminated glass article according to any of the aspects (1)-(14), wherein an entirety of the second edge surface is under compressive stress.

[0020] An aspect (16) of the present disclosure pertains to a laminated glass article, comprising: a first glass substrate comprising a first major surface, a second major surface opposite the first major surface, a first edge surface joining the first major surface and the second major surface, and a first thickness extending between the first major surface and the second major surface; a second glass substrate comprising a third major surface, a fourth major surface opposite the third major surface, a second edge surface joining the third major surface and the second major surface, and a second thickness extending between the third major surface and the fourth major surface; and a polymer interlayer disposed between and joining with the second major surface and the third major surface, the polymer interlayer comprising an interlayer edge surface, wherein: the laminated glass article comprises a total thickness extending between the first major surface and the fourth major surface, the total thickness being greater than or equal to 1.8 mm and less than or equal to 6.85 mm, a composite edge surface of the laminated glass article extends from the first major surface to the fourth major surface and includes the first edge surface, the second edge surface, and the interlayer edge surface, the composite edge surface defining an arc between the first major surface and the fourth major surface with a continuous curvature, and the arc comprises a minimum radius of curvature that is greater than or equal to the total thickness.

[0021] An aspect (17) of the present disclosure pertains to a laminated glass article according to the aspect (16), wherein the arc comprises no inflection points.

[0022] An aspect (18) of the present disclosure pertains to a laminated glass article according to the aspect (17), wherein the arc comprises a constant radius of curvature such that the arc is a circular arc.

[0023] An aspect (19) of the present disclosure pertains to a laminated glass article according to the aspect (18), wherein the arc comprises a center of curvature disposed within the first glass substrate or on the first major surface.

[0024] An aspect (20) of the present disclosure pertains to a laminated glass article according to any of the aspects (16)-( 19), wherein the minimum radius of curvature is greater than or equal to 1.0 mm.

[0025] An aspect (21) of the present disclosure pertains to a laminated glass article according to any of the aspects ( 16)-(20), wherein: the first thickness is greater than or equal to 2.5 mm and less than or equal to 6.0 mm, the second thickness is greater than or equal to 0.5 mm and less than or equal to 0.7 mm, and the interlayer comprises a thickness that is greater than or equal to 0.3 mm.

[0026] An aspect (22) of the present disclosure pertains to a laminated glass article according to any of the aspects ( 16)-(21), wherein the interlayer has a modulus of elasticity ranging from 1 MPa to 75 MP.

[0027] An aspect (23) of the present disclosure pertains to a laminated glass article according to the aspect (16), wherein the interlayer comprises a central portion comprising a peripheral edge and a peripheral portion extending outward from the peripheral edge, the peripheral portion contacting the first glass substrate and the second glass substrate and forming a portion of the composite edge surface.

[0028] An aspect (24) of the present disclosure pertains to a laminated glass article according to the aspect (23), wherein a modulus of elasticity of the peripheral portion is greater than a modulus of elasticity of the central portion.

[0029] An aspect (25) of the present disclosure pertains to a laminated glass article according to the aspect (16), wherein the composite edge surface is coated with a perfluoropolyether coating or a polymer coating with a molecular weight greater than about 106grams / mole.

[0030] An aspect (26) of the present disclosure pertains to a laminated glass article according to the aspect (16), wherein, when an edge of the fourth major surface is impacted with a 144 g gram cylindrical stainless steel weight at an impact angle of 30° with an impact energy of 0.3 J, the second glass substrate does not fracture from the impact, and the second glass substrate comprises a maximum tensile stress that is greater than that of the first glass substrate as a result of being strengthened to a greater extent than the first glass substrate

[0031] An aspect (27) of the present disclosure pertains to a laminated glass article according to the aspect (26), wherein: the second thickness is greater than or equal to 0.9 mm and less than or equal to 1.5 mm and the second glass substrate is chemically strengthened such that the fourth major surface comprises a surface compressive stress greater than or equal to 600 MPa, and when the weight impacts the edge of the fourth major surface with an impact energy of 0.6 J, the second glass substrate does not break from the impact.

[0032] An aspect (28) of the present disclosure pertains to a laminated glass article according to the aspect (26), wherein: the second thickness is greater than or equal to 1.1 mm and less than or equal to 1.5 mm and the second glass substrate is chemically strengthened such that the fourth major surface comprises a surface compressive stress greater than or equal to 600 MPa, and when the weight impacts the edge of the fourth major surface with an impact energy of 0.75 J, the second glass substrate does not break from the impact.

[0033] An aspect (29) of the present disclosure pertains to a laminated glass article according to any of the aspects (16)-(28), wherein an entirety of the second edge surface is under compressive stress.

[0034] An aspect (30) of the present disclosure pertains to a laminated glass article comprising: a first glass substrate comprising a first major surface, a second major surface opposite the first major surface, and a first edge surface joining the first major surface and the second major surface; a second glass substrate comprising a third major surface, a fourth major surface opposite the third major surface, and a second edge surface joining the third major surface and the second major surface; a polymer interlayer disposed between and joining with the second major surface and the third major surface; and wherein a composite edge surface of the laminate glass article extends from the first major surface to the fourth major surface and includes the first edge surface, the second edge surface, and an edge surface of the polymer interlayer, the composite edge surface formed by the first edge surface of the first glass substrate, the second edge surface of the second glass substrate, and an edge surface of the interlayer, the composite edge surface coated with a perfluoropolyether coating or a polymer coating with a molecular weight greater than about 106grams / mole.

[0035] An aspect (31) of the present disclosure pertains to a laminated glass article according to the aspect (30), wherein the composite edge surface defines an arc between the first major surface and the second major surface with a continuous curvature.

[0036] An aspect (32) of the present disclosure pertains to a laminated glass article according to the aspect (31), wherein the arc comprises no inflection points.

[0037] An aspect (33) of the present disclosure pertains to a laminated glass article according to the aspect (32), wherein the arc comprises a constant radius of curvature such that the arc is a circular arc.

[0038] An aspect (34) of the present disclosure pertains to a laminated glass article according to the aspect (33), wherein the arc comprises a center of curvature disposed within the first glass substrate or on the first major surface.

[0039] An aspect (35) of the present disclosure pertains to a laminated glass article according to any of the aspects (30)-(34), wherein the composite edge surface comprises a minimum radius of curvature that is greater than or equal to one fourth of a total thickness of the laminated class article, wherein the total thickness is greater than or equal to 1.8 mm and less than or equal to 1.5 mm.

[0040] Additional features of the embodiments disclosed herein will be set forth in the detailed description that follows, and in part will be clear to those skilled in the art from thatdescription, including the claims and appended drawings. Both the foregoing general description and the following detailed description present embodiments intended to provide an overview or framework for understanding the nature and character of the embodiments. The accompanying drawings are included to provide further understanding and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the disclosure, and together with the description explain the principals and operations thereof.BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG. 1 is a cross-sectional view of a traditional monolithic glass article (window glass) used in vehicle side window applications;

[0042] FIG. 2 is a cross-sectional profile of a traditional laminated glass article (window glass) used in vehicle side window applications having glass substrate constituents with equal thickness and joined by a recessed interlayer;

[0043] FIG. 3 is cross-sectional view of another traditional glass article (window glass) used in vehicle side window applications comprising a recessed second (inside) glass substrate;

[0044] FIG. 4 is a cross-sectional view of an edge profile for a laminated glass article (window glass) according to embodiments disclosed herein, the glass article useable in vehicle side window applications having a composite edge surface with continuous curvature (e.g., a bullnose profile);

[0045] FIG. 5 is a cross-sectional view of an edge profile for another laminated glass article in accordance with embodiments of the present disclosure useable in vehicle side window applications and having a composite edge surface with continuous curvature (e.g., a bullnose profile), and a composite interlayer including a central portion and a peripheral portion with different elastic moduli;

[0046] FIG. 6 is a cross-sectional view of an edge profile for another laminated glass article in accordance with embodiments of the present disclosure useable in vehicle side window applications and having a composite edge surface with continuous curvature (e.g., a bullnose profile), and a composite interlayer including a central portion and a peripheral portion with different elastic moduli, the peripheral portion having varying thickness;

[0047] FIG. 7 is a cross-sectional view of an edge profile for another laminated glass article in accordance with embodiments of the present disclosure useable in vehicle side window applications and having a composite edge surface with continuous curvature (e.g., a bullnose profile), wherein the continuous curvature subtends an angle of about 90 degrees;

[0048] FIG. 8A is a cross-sectional view of an edge profile for another laminated glass article in accordance with embodiments of the present disclosure useable in vehicle side window applications and having a composite edge surface with discontinuous curvature, the composite edge surface coated with a low-friction coating;

[0049] FIG. 8B is a cross-sectional close-up view of the region A shown in FIG. 8A;

[0050] FIG. 9 is a side view of an exemplary vehicle comprising a side window formed from a laminated glass article disclosed herein;

[0051] FIG. 10A-10D are schematic views indicating how sample edge profiles were modeled for contact pressure against a simulated weather seal material found in automotive application for sealing side windows;

[0052] FIG. 11 is a cross-sectional view showing the modeled edge profile for a traditional laminated glass article as the glass article is moved across a simulated seal material;

[0053] FIG. 12 is a cross-sectional view showing the modeled edge profile for a laminated glass article with a composite edge surface having a continuous curvature (e.g., bullnose) as the glass article is moved across a simulated seal material;

[0054] FIG. 13 is a cross-sectional view showing the modeled edge profile for a laminated glass article with a composite edge surface having a continuous curvature subtending about 90 degrees, and shown as the glass article is moved across a simulated seal material;

[0055] FIG. 14A and 14B are cross-sectional profiles of a traditional composite edge profile showing the difference in distortion of the seal material for different coefficient of friction;

[0056] FIG. 15 is a schematic view of an impact testing apparatus used to test the impact resistance of glass articles;

[0057] FIG. 16 shows cross-sectional views (a)-(d) of glass samples evaluated using modeling and the virtual testing apparatus of FIG. 15; and

[0058] FIG. 17 is a plot showing modeled stress as a function of time for the four sample types (a)-(d) shown in FIG. 16.DETAILED DESCRIPTION

[0059] Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. However, this disclosure can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[0060] As used herein, the term “about” means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and / or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art.

[0061] Ranges can be expressed herein as from “about” one particular value, and / or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value 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 embodiment. 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.

[0062] Directional terms as used herein — for example, up, down, right, left, front, back, top, bottom — are made only with reference to the figures as drawn and are not intended to imply absolute orientation.

[0063] Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order, nor that with any apparatus specific orientations be required. Accordingly, where a method claim does not actually recite an order to be followed by its steps, or that any apparatus claim does not actually recite an order or orientation to individual components, or it is not otherwise specifically stated in the claims or description that the steps are to be limited to a specific order, or that a specific order or orientation to components of an apparatus is not recited, it is in no way intended that an order or orientation be inferred in any respect. This holds for any possible non-express basis for interpretation, including matters of logic with respect to arrangement of steps, operational flow, order of components, or orientation of components, plain meaning derived from grammatical organization or punctuation, and the number or type of embodiments described in the specification.

[0064] As used herein, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Thus, for example, reference to “a” component includes embodiments having two or more such components, unless the context clearly indicates otherwise.

[0065] The word “exemplary,” “example,” or various forms thereof are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “exemplary” or as an “example” should not be construed as preferred or advantageous over other aspects or designs. Furthermore, examples are provided solely for purposes of clarityand understanding and are not meant to limit or restrict the disclosed subject matter or relevant portions of this disclosure in any manner. It can be appreciated that a myriad of additional or alternate examples of varying scope could have been presented but have been omitted for purposes of brevity.

[0066] As used herein, the terms “comprising” and “including,” and variations thereof, shall be construed as synonymous and open-ended, unless otherwise indicated. A list of elements following the transitional phrases comprising or including is a non-exclusive list, such that elements in addition to those specifically recited in the list may also be present.

[0067] The terms “substantial,” “substantially,” and variations thereof as used herein are intended to note that a described feature is equal or approximately equal to a value or description. For example, a “substantially planar” surface is intended to denote a surface that is planar or approximately planar. Moreover, “substantially” is intended to denote that two values are equal or approximately equal. In some embodiments, “substantially” may denote values within about 10% of each other, such as within about 5% of each other, or within about 2% of each other.

[0068] Automotive side windows have traditionally been monolithic sheets of tempered glass formed to a specific shape as needed for the particular automobile design. Such side windows have generally been of a movable design, wherein the glass sheet is contained in or attached to a mechanical assembly configured to move the window into position within an opening in the vehicle. The side window may be moved by a mechanical apparatus, termed a regulator, such as a scissor jack, or a cable loop assembly wherein the cable runs through various tracks and guides. The regulator can be powered by a hand crank, or in more modem embodiments, the motive power can be provided by an electric motor. In some instances, the door itself may define the opening, wherein the opening is bounded by a lower portion of the door and a frame that extends upward and around the opening. The frame may include a channel configured to receive an edge of the window, thereby securing the window in place when moved into position.

[0069] In other variations, the door lacks a defining frame and the opening is bounded by both the door and the body of the vehicle, for example the vehicle roof, when the door is in a closed positioned. The body portion with which the window engages typically includes a resilient seal material, e.g., weather sealing, around at least a portion of the opening. When the window is moved into the closed position, either by movement of the window within the door’s window frame, or by closing the door and the window is moved, either in the “up” (closed) direction or in the down (open) direction, the inside portion of the window edge is pressed to and movesagainst the seal material. The seal material generally has sufficient resilience to deform when engaged with the window edge and seal the interior of the vehicle against water entry between the seal and the window. The seal may also reduce interior noise in the cabin of the vehicle. Depending on the window edge shape and the resilience of the seal material, the seal material in contact with the window edge deforms to conform at least partially with the geometry of the edge. However, continued operation of the window up and down within the window opening can create significant wear on the seal material and may result in a decreased life of the seal material. This wear can be exacerbated by the geometry and / or material-related friction characteristics of the window relative to the seal material, particularly in the case of a window constructed of laminated glass, effects that can be mitigated by edge profile and / or material changes that reduce friction between the window and the seal material.

[0070] As shown in FIG. 1, a typical monolithic window 10, such as a side window for a vehicle, comprises a first major surface 12 and a second major surface 14 opposite the first major surface. An edge surface 16 joins the first major surface and the second major surface and typically exhibits a bullnose shape. That is, edges of the window are ground to present a continuous curvature between the first and second major surfaces. The edges of monolithic window 10 are easy to fabricate, and a singular bullnose edge surface is generally considered aesthetically pleasing. However, a monolithic window is not as acoustically effective at reducing cabin noise (e.g., noise in the interior of the vehicle) that may occur, for example as a result of air traveling over the exterior of the vehicle as the vehicle is moving.

[0071] As used herein, an edge of an article with a “continuous curvature” means that a cross section of the article, taken perpendicular to the edge, includes a minor surface at a periphery thereof that comprises no linear segments greater than a length of 1 pm. That is, if the crosssection is imaged and a 1 pm long line is drawn between two points on the minor surface in the cross section, the line deviates from the surface. Such edges with “continuous curvature” can comprise a constant radius of curvature or a variable radius of curvature in various configurations. Such continuous curvature is visible to the naked eye without magnification by visually inspecting the edge from a distance less than 100 cm. In embodiments arc segments with continuous curvature in the laminated glass articles described herein may have an arc length that is greater than an arc length associated with an edge of a thicker of two glass layers in the laminated glass articles, such that the arc with continuous curvature comprises an arc length that is more than 50% of a total arc length associated with the edge of the laminated glass article.

[0072] Glass laminates are acoustically superior to monolithic glass and can be made thinner while exhibiting similar or better strength characteristics than monolithic glass. Moreover, for vehicle applications, thinner glass can mean reduced vehicle weight. Laminates are generally less stiff than monolithic glass articles of the same thickness and can dissipate impact energy through flexure. Moreover, asymmetric laminates, including one ply that is thinner than the other, can be more stiff (resistant to bending) than symmetric laminates of the same thickness to provide improved strength. Referring to FIG. 2, a glass laminate 20 used in vehicle side window applications can be constructed with a first glass substrate 22, a second glass substrate 24, and an interlayer 26 disposed therebetween joining the first and second glass substrates, for example a polymer interlayer. Each of first and second glass layers 22 and 24, typically of the same thickness (e.g., about 1.5 mm) and the same glass composition (e.g., soda lime glass), include a bullnose edge surface 28, 30, respectively. As shown, each glass substrate extends to a common plane, with the interlayer recessed relative to the two glass substrates. The double bullnose design of the composite laminate edge surface shown in FIG. 2 (a combination of the edge surface of the first and second glass substrates and the intervening interlayer) is less aesthetically pleasing than the continuous curvature of the single bullnose edge provided by monolithic window 10, particularly in view of the recessed interlayer.

[0073] In still other instances, shown in FIG. 3, a glass laminate 30 may be employed, wherein the glass laminate comprises a first glass substrate 32 of a first thickness and a second glass substrate 34 of a second thickness. The first and second glass layers 32, 34, like glass laminate 20, are joined by an interlayer 36 positioned between the first and second glass substrates, such as a polymer interlayer. Each of first and second glass substrates 32 and 34 include a bullnose edge surface 38, 40, respectively. In the embodiment of FIG. 3, first glass substrate 32 comprises a first thickness 42 defined between a first major surface 44 and a second major surface 46, and second glass substrate 34 comprises a second thickness 48 defined between third major surface 50 and fourth major surface 52. In the illustrated embodiment, second thickness 48 is different than first thickness 42. More particularly, second thickness 48 can be less than first thickness 42, although in further embodiments, first thickness 42 can be less than second thickness 48. In typical vehicle installations, first glass substrate 32 is the outsidefacing glass substrate and second glass substrate 34 is the inside-facing glass substrate (e.g., facing into the interior of the vehicle). That is, first major surface 44 can comprise an exposed convex surface while fourth major surface 52 can comprise an exposed concave surface such that when installed in a vehicle, the laminated glass article bows outward, away from the interior (cabin) of the vehicle. In some embodiments, the curvature of the laminate glass article,for example the convex curvature of the outside -facing glass substrate can comprises a first curvature along a first axis, a second curvature along a second axis different from the first curvature. The second axis can be oriented differently than the first axis, for example orthogonal to the first axis. Glass substrates, includes laminated glass articles described herein, are termed complexly-curved when the glass article comprises curvature along two distinctly different axes, whether the curvatures are equal or different.

[0074] Often, a chemical composition of the second glass substrate 34 is different than a chemical composition of the first glass substrate 32. For example, the first (exterior) glass substrate may comprise a soda lime glass or borosilicate glass, whereas the second (interior) glass substrate may be an aluminosilicate glass (e.g., a chemically strengthened aluminosilicate glass) or soda lime glass (e.g., a partially or fully thermally tempered soda lime glass). The edge profiles described herein can provide benefits irrespective of the composition of the glass substrates. In some instances, the second glass substrate facing the interior of the vehicle will be strengthened, such as chemically strengthened by an ion exchange process, although other strengthening methods, such as thermal or mechanical strengthening, may be used. The first glass substrate 32 can also be strengthened (e.g. annealed or partially tempered). A strengthened inside glass substrate can be made thinner than the outside glass substrate while still providing adequate resistance to breakage. In the embodiment of FIG. 3, the inside glass substrate 34 is recessed relative to outside glass substrate 32. That is, the second edge surface 40 (e.g., an apex thereof) of second glass substrate 34 is recessed by an amount 54 relative to first edge surface 38 of first glass substrate 32.

[0075] The laminated glass article of FIG. 3 can offer reduced thickness and weight with strength comparable to or greater than that of monolithic glass articles, or even laminated glass articles with glass substrates of the same thickness and / or composition. However, the thin inside glass substrate may degrade the flexible seal material used to seal the glass laminate article, either in the vehicle door window frame or the vehicle body, depending on the vehicle design. As previously described, this seal can provide noise reduction and a weather-resistant barrier. Vehicle side windows are usually configured to raise and lower, and therefore ride over the seal material (for example a synthetic rubber). Repeated rubbing against the seal material by the thin interior glass substrate as the window is raised and lowered, and particularly the edge surface of the interior glass substrate, may cause premature failure of the seal material, increasing cabin noise and allowing moisture (e.g., rain) to enter the vehicle interior.

[0076] Accordingly, a laminated glass article is disclosed herein that can address at least some of the shortcomings of previous generations of glass glazing for vehicle side windows, or any other window that repeatedly slides against a resilient material like a weather seal. For example, laminated glass articles disclosed herein may reduce seal material wear, thereby increasing the life of the seal material while providing a more aesthetically pleasing appearance, particularly when the window is in a down or partially down position and therefore visible.

[0077] In accordance with embodiments of the present disclosure, FIG. 4 depicts a cross- sectional view of an exemplary laminated glass article 100 comprising a first glass substrate 102 having a first major surface 104 and a second major surface 106 opposite the first major surface. A first edge surface 108 joins the first major surface and the second major surface about a periphery of the first glass substrate. A first thickness 110 is defined between first major surface 104 and second major surface 106 along a normal to at least one of the first major surface or the first major surface. First thickness 110 can be in a range from about 1.6 mm to about 6 mm, from about 1.7 mm to about 6 mm, from about 1.8 mm to about 6 mm, from about 1.9 mm to about 6 mm, from about 2 mm to about 6 mm, from about 2.1 mm to about 6 mm, from about 2.2 mm to about 6 mm, from about 2.3 mm to about 6 mm, from about 2.4 mm to about 6 mm, from about 2.5 mm to about 6 mm, from about 2.6 mm to about 6 mm, from about 2.8 mm to about 6 mm, from about 3 mm to about 6 mm, from about 3.2 mm to about 6 mm, from about 3.4 mm to about 6 mm, from about 3.6 mm to about 6 mm, from about 3.8 mm to about 6 mm, from about 4 mm to about 6 mm, from about 1.6 mm to about 5.8 mm, from about 1.6 mm to about 5.6 mm, from about 1.6 mm to about 5.5 mm, from about 1.6 mm to about 5.4 mm, from about 1.6 mm to about 5.2 mm, from about 1.6 mm to about 5 mm, from about 1.6 mm to about 4.8 mm, from about 1.6 mm to about 4.6 mm, from about 1.6 mm to about 4.4 mm, from about 1.6 mm to about 4.2 mm, from about 1.6 mm to about 4 mm, from about 3.8 mm to about 5.8 mm, from about 1.6 mm to about 3.6 mm, from about 1.6 mm to about 3.4 mm, from about 1.6 mm to about 3.2 mm, or from about 1.6 mm to about 3 mm. In various embodiments, first major surface 104 may be parallel with second major surface 106 such that first thickness 110 is constant, although in further embodiments, first thickness 110 may vary. For example, in certain embodiments, first glass substrate 102 may be wedge-shaped. Unless otherwise indicated, first glass substrate 102 is an exterior (outside) glass substrate.

[0078] Laminated glass article 100 further comprises a second glass substrate 120 having a third major surface 124 and a fourth major surface 126 opposite third major surface 124. A second edge surface 128 joins third major surface 124 and fourth major surface 126 about aperiphery of second glass substrate 120. A second thickness 130 is defined between third major surface 124 and fourth major surface 126 along a normal to at least one of the third major surface or the fourth major surface. In embodiments, the second thickness is equal to the first thickness 110 such that the laminated glass article 100 comprises a symmetrical thickness profile, with an axis of symmetry (not depicted) extending through the interlayer 130. In embodiments, the first thickness 110 is greater than the second thickness 130 such that the laminate 100 comprises an asymmetric thickness profile, with a thickness center of the laminate 100 being disposed in the first glass substrate 102.

[0079] In embodiments (e.g., where the laminate 100 comprises an asymmetric thickness profile), the second thickness 130 can be in a range from about 0. 1 mm to equal to or less than about 1.6 mm, from about 0. 1 mm to about 1.5 mm, from about 0.1 mm to about 1.4 mm, from about 0.1 mm to about 1.3 mm, from about 0.1 mm to about 1.2 mm, from about 0.1 mm to about 1.1 mm, from about 0.1 mm to about 1 mm, from about 0.1 mm to about 0.9 mm, from about 0.1 mm to about 0.8 mm, from about 0. 1 mm to about 0.7 mm, from about 0.1 mm, from about 0.2 mm to equal to or less than about 1.6 mm, from about 0.3 mm to equal to or less than about 1.6 mm, from about 0.4 mm to less than about 1.6 mm, from about 0.5 mm to equal to or less than about 1.6 mm, from about 0.6 mm to equal to or less than about 1.6 mm, from about 0.7 mm to equal to or less than about 1.6 mm, from about 0.8 mm to equal to or less than about 1.6 mm, from about 0.9 mm to equal to or less than about 1.6 mm, or from about 1 mm to about 1.6 mm. In various embodiments, third major surface 124 may be parallel with fourth major surface 126 such that second thickness 130 is constant, although in further embodiments, second thickness 130 may vary. For example, in certain embodiments, second glass substrate 120 may be wedge-shaped.

[0080] First glass substrate 102 is joined to second glass substrate 120 by an interlayer 132, for example a polymer interlayer, disposed between first glass substrate 102 and second glass substrate 120. That is, second major surface 106 can be joined to and in direct contact with a first surface 134 of interlayer 132 and third major surface 124 can be joined to and in direct contact with a second surface 136 of interlayer 132 opposite first surface 134 such that second major surface 106 of first glass substrate 102 is opposite third major surface 124 of second glass substrate 120. In some embodiments, interlayer 132 can comprise multiple layers, for example a light absorbing layer (e.g., a tint layer), a photochromic layer, an electrochromic layer, and the like . The interlayer (or one or more layers thereof) may be formed from polymers such as polyvinyl butyral (PVB), acoustic PBV (APVB), ionomers, ethylene-vinyl acetate (EVA), thermoplastic polyurethane (TPU), polyester (PE), polyethylene terephthalate (PET),and the like. A third thickness 138 of interlayer 132 is defined between first surface 134 and second surface 136 along a normal to at least one of second major surface 106 or third major surface 124. Third thickness 138 may be in a range from about 0.5 mm to about 2.5 mm, for example from about 0.8 mm to about 2.5 mm, from about 1 mm to about 2.5 mm, or from about 1.5 mm to about 2.5 mm. In some embodiments, interlayer 132 may have a non-uniform thickness, e.g., a wedge shape, from one edge to another edge (e.g., an opposing edge) of the interlayer.

[0081] Additionally, a fourth thickness 140, an overall thickness of laminated glass article 100, is defined between first major surface 104 and fourth major surface 126, where the fourth thickness comprises the sum of first, second, and third thicknesses 110, 130, and 138 of first glass substrate 102, second glass substrate 120, and interlayer 132, respectively. Fourth thickness 140 can be, 10.0 mm or less, 6.85 mm or less, or 5.85 mm or less. In various embodiments, fourth thickness 140 can be in a range from about 1.8 mm to about 6.85 mm, or in a range from about 1.8 mm to about 5.85 mm, or in a range from about 1.8 mm to about 5.0 mm, or in a range from about 2. 1 mm to about 6.85 mm, or in a range from about 2.1 mm to about 5.85 mm, or in a range from about 2. 1 mm to about 5.0 mm, or in a range from about 2.4 mm to about 6.85 mm, or in a range from about 2.4 mm to about 5.85 mm, or in a range from about 2.4 mm to about 5.0 mm, or in a range from about 3.4 mm to about 6.85 mm, or in a range from about 3.4 mm to about 5.85 mm, or in a range from about 3.4 mm to about 5.0 mm. In various embodiments, first major surface 104 may be parallel with fourth major surface 126 such that fourth thickness 140 is constant, although in further embodiments, fourth thickness 140 may vary. For example, in certain embodiments, laminated glass article 100 may be wedge-shaped.

[0082] In some embodiments, laminated glass article 100 can be a planar laminated glass article. However, in further embodiments, laminated glass article 100 can be a curved laminated glass article. For example, laminated glass article 100 can have a first curvature along a first axis and a second curvature along a second axis. The first curvature can be different than the second curvature. That is, a radius of curvature of the first curvature can be different than a radius of curvature of the second curvature, although his does not preclude the first and second curvatures from being equal. The first axis can be orthogonal to the second axis, although other angular orientations are contemplated. As previously described, when the second axis is different than the first axis, the laminated glass article is said to be complexly curved.

[0083] As described herein, first glass substrate 102 may alternatively be referred to as the exterior or outside glass substrate. That is, first major surface 104 of first glass substrate 102 faces outward when installed in a vehicle, away from the vehicle interior. First major surface 104 may present a convex outward -facing surface. Second glass substrate 120 may alternatively be referred to as the inside glass substrate, wherein fourth major surface 126 faces inward toward the interior of the vehicle. Fourth major surface 126 may present a concave surface to the interior of the vehicle. However, positions of the glass substrates may be interchanged such that interlayer first surface 134 is adjacent fourth major surface 126 and interlayer second surface 136 is adjacent first major surface 104. In such embodiments, second major surface 106 forms a concave surface and the third major surface 124 forms a convex surface. That is, second glass substrate 120 can be the outside glass substrate and first glass substrate 102 can be the inside glass substrate.

[0084] At least one of first major surface 104 or fourth major surface 126 may be bare and substantially free of any coatings. However, in other embodiments, first glass substrate 102 and / or second glass substrate 120 may include a coating or surface treatment (e.g., antireflective coating, anti-glare coating or surface, easy-to-clean surface, ink decoration, conductive coating etc.). The coating or surface treatment may be applied to first major surface 104 and / or fourth major surface 126, or the coating or treatment may be applied to second major surface 106 and / or third major surface 124, depending on construction of the laminated glass article. In some embodiments, the laminated glass article may include one or more conductive coatings on any one or more of first major surface 104 (e.g., outside surface) and / or fourth major surface 126 (e.g., inside surface), second major surface 106, or third major surface 124.

[0085] In one or more embodiments, one of the first glass substrate or the second glass substrate may comprise soda lime silicate glass, an alkali aluminosilicate glass, alkali containing borosilicate glass, alkali aluminophosphosilicate glass, or alkali aluminoborosilicate glass. For example, the first glass substrate may be a soda lime silicate glass, while the second glass substrate comprises an alkali aluminosilicate glass, an alkali containing borosilicate glass, an alkali aluminophosphosilicate glass, or an alkali aluminoborosilicate glass.

[0086] In one or more embodiments, at least one of the first glass substrate or the second glass substrate may be strengthened to include compressive stress that extends from a surface of the glass substrate to a depth within the body of the glass substrate, i.e., the depth of compression (DOC). The compressive stress regions are balanced by a central portion of the glass substratebody exhibiting a tensile stress. At the DOC, the stress crosses from a positive (compressive) stress to a negative (tensile) stress.

[0087] Such strengthened glass substrates may be chemically strengthened, mechanically strengthened, hydration strengthened, or thermally strengthened. In some embodiments, the strengthened glass substrate may be chemically and mechanically strengthened, mechanically and thermally strengthened, chemically and thermally strengthened, or chemically, mechanically, and thermally strengthened. In some embodiments, the second glass substrate is strengthened and the first glass substrate is unstrengthened but may be optionally annealed. In one or more embodiments, the first glass substrate can be strengthened. In specific embodiments, both the first glass substrate and the second glass substrate may be strengthened. Where one or both the glass substrates are chemically and / or thermally strengthened, such chemical and / or thermal strengthening may be performed on the glass substrate after shaping. Such glass substrates may optionally be mechanically strengthened before shaping. Where one or both the glass substrates are mechanically strengthened (and optionally combined with one or more other strengthening methods), such mechanical strengthening may occur before shaping.

[0088] In some embodiments, at least one of the first glass substrate or the second glass substrate may be strengthened mechanically by utilizing a mismatch of the coefficient of thermal expansion between portions of the laminated glass article to create a compressive stress region and a central region exhibiting a tensile stress.

[0089] In some embodiments, at least one of the first glass substrate or the second glass substrate may be strengthened thermally by heating the glass substrate to a temperature below the glass transition point and then rapidly thermally quenching. As noted above, where one or both the glass substrates are thermally strengthened, such thermal strengthening may be performed on the glass substrate after shaping.

[0090] In some embodiments, at least one of the first glass substrate or the second glass substrate may be chemically strengthened by ion exchange. Where at least one of the first glass substrate or the second glass substrate is chemically strengthened, such chemical strengthening may be performed on the glass substrate after shaping. In the ion exchange process, ions at or near the surface of the glass substrate are replaced by - or exchanged with - larger ions having the same valence or oxidation state. In those embodiments in which the glass substrate comprises a composition including at least one alkali metal oxide as measured on an oxide basis (e.g., Li2O , Na2O, K2O, Rb2O, or CS2O), ions in the surface layer of the article and the larger ions are monovalent alkali metal cations, such as Li+, Na+, K+, Rb+, and Cs+.Alternatively, monovalent cations in the surface layer may be replaced with monovalent cations other than alkali metal cations, such as Ag+or the like. The monovalent ions (or cations) exchanged into the glass substrate generate a compressive stress on the surface portions balanced by a tensile stress in the central portions.

[0091] As further shown in FIG. 4, laminated glass article 100 comprises a composite edge surface 142 that is a combination of at least the first edge surface 108, the second edge surface 128, and an edge surface 144 of interlayer 132 extending between first surface 134 and second surface 136. Composite edge surface 142 exhibits a continuous curvature, such as a “C”-shape, when viewed in cross-section (on a plane intersecting the glass article orthogonal to either one or both first major surface 104 and fourth major surface 126). By continuous curvature what is meant is a curvature of an edge profile extending between one major surface to another, e.g., opposite, major surface with no intervening linear sections. When applied to a composite edge surface of a laminated glass article, the term references the entire edge surface of the laminated glass article, from one exposed, externally facing major surface to the opposite exposed, externally-facing major surface, e.g., from first major surface 104 to fourth major surface 126. Composite edge surface 142 may have a constant or substantially constant radius of curvature 146 between first major surface 104 and fourth major surface 126. That is, composite edge surface 142 may be a circular arc. In some embodiments, composite edge surface 142 can be a semicircular edge surface such that radius of curvature 146 of the composite edge surface is one half the fourth thickness 140 of the laminated glass article, although in further embodiments, radius of curvature 146 can be less than or greater than fourth thickness 140. When composite edge surface 142 is semicircular such that radius of curvature 146 is constant and one half fourth thickness 140 (that is, one half the overall thickness of the laminated glass article), the composite edge surface joins with the exposed major surfaces of the laminated glass article (e.g., the first and fourth major surfaces 104, 126) asymptotically, with no abrupt changes that might create additional resistance when sliding against a seal material. However, composite edge surface 142 need not have a circular (constant radius) profile. For example, in some embodiments, the composite edge surface profile may be parabolic or semi-elliptical when viewed in cross-section on a plane orthogonal to one or both the first major surface or the second major surface. In some embodiments, the center of curvature 148 can be located at a midpoint between the first major surface and the fourth major surface, i.e., midway along fourth thickness 140. In other embodiments, center of curvature 148 may not lie at the midpoint between the first and fourth major surfaces. In embodiments where composite edge surface 142 is of constant radius of curvature, each one of edge surfaces 108, 128, and 144 has aconstant radius of curvature, and the radius of curvature of first edge surface 108 is equal to the radius of curvature of second edge surface 128 and edge surface 144.

[0092] Referring to FIG. 5, in another embodiment, a laminated glass article 200 is shown, wherein laminated glass article 200 is substantially the same as laminated glass article 100, with the exception that interlayer 132 comprises a central first portion 150 having a first modulus of elasticity and a second, peripheral portion 152 having a second modulus of elasticity, wherein both central portion 150 and peripheral portion 152 are in contact with second major surface 106 and third major surface 124. To wit, peripheral portion 152 extends outward from a peripheral edge 154 of central portion 150, thereby forming a band that extends around at least a portion of, or the entirety of, central portion 150. For example, in various embodiments, peripheral portion 152 may not overlap central portion 150 in a thickness direction of the laminated glass article (i.e., along a normal to at least one of the second or third major surfaces). In various embodiments, the second modulus of elasticity can be greater than the first modulus of elasticity, thereby reducing friction at the interface between the interlayer and a seal material when relative motion occurs between the interlayer and the seal material when the interlayer is in contact with the seal material. Unless otherwise noted herein, the term “modulus of elasticity” means Young’s modulus measured at 23° and at load duration of 1 second.

[0093] In still further embodiments, at least one of edge surfaces 108, 128, or 146 may have a non-constant radius of curvature. For example, the embodiment depicted in FIG. 6 illustrates a laminated glass article 300 wherein first edge surface 108 of first glass substrate 102 exhibits a non-constant radius of curvature. Further, rather than interlayer 132 having a constant third thickness 138, third thickness 138 can vary. In the embodiment of FIG. 6, peripheral portion 152 of interlayer 132 increases in thickness at composite edge surface 142 compared to a thickness spaced inward from the composite edge surface. In this embodiment, edge surface 144 of interlayer 132 (e.g., a portion of peripheral portion 152) overlays a portion of first edge surface 108. However, composite edge surface 142 in this embodiment nevertheless comprises a circular arc edge profile of constant radius (when viewed in cross-section). Of course, the arrangement shown in FIG. 6 could be reversed, wherein second edge surface 128 of second glass substrate 120 exhibits a non-constant radius of curvature, and at least a portion of interlayer 132, for example a portion of peripheral portion 152, overlays a portion of second edge surface 128. In other embodiments, both first edge surface 108 and second edge surface 128 can exhibit a non-constant radius of curvature, and at least a portion of interlayer 132 can overlay a portion of first edge surface 108 and a portion of second edge surface 128. The radiiof curvature of first edge surface 108 need not be the same or otherwise match the radii of curvature of second edge surface 128. Nevertheless, in such embodiments, composite edge surface 142 maintains a continuous curvature and a constant radius of curvature. In embodiments, the arc defined by the composite edge can extend an entirety of the distance between the first major surface 102 and the fourth major surface 126. In such embodiments, it should be understood that the arc can extend an entirety of the distance between the first major surface and the fourth major surface 126 with the very comers (at the transitions between the composite edge surface 142 and the first and fourth major surfaces 102 and 126) varying from the arc due to edge processing (e.g., grinding and polishing). That is, as used herein, the term “entirety,” when used to describe the shape of the arc defined by a composite edge, refers to a substantial majority of the edge surface excluding the very comers of the laminate.

[0094] FIG. 7 depicts yet another laminated glass article 400. As shown, laminated glass article 400 is substantially the same as the laminated glass article embodiments depicted in FIGS. 4-5 in that laminated glass article 400 comprises a first glass substrate 102 joined to a second glass substrate 120 by an interlayer 132. Like the previous embodiments, first glass substrate 102 comprises a first major surface 104 and a second major surface 106 opposite first major surface 104. Second glass substrate 120 similarly comprises a third major surface 124 and a fourth major surface 126 opposite third major surface 124. Interlayer 132 comprises a first surface 134 and a second surface 136, wherein first surface 134 is attached to second major surface 106 and second surface 136 is attached to third major surface 124, thereby forming a laminated structure. Various other attributes described for laminated glass articles 100 and 200, for example thicknesses, may apply equally to laminated glass article 400. However, laminated glass article 400 differs from laminated glass articles 100 and 200 in that composite edge surface 402 of the laminated glass article exhibits a continuous curvature, for example a circular arc, that is not semi-circular in nature. That is, composite edge surface 402 may be substantially a quarter circular arc of constant radius of curvature subtending approximately 90 degrees, for example in a range from about 95 degrees to 90 degrees. The center of curvature 148 may be located at, on, or near first major surface 104. That is, the center of curvature 148 may be positioned at, on, or near the exposed major surface of the laminated glass article that is opposite the exposed major surface of the glass substrate that contacts the seal material, e.g., the inside glass substrate. The subtended angle is determined between a ray extending from center of curvature 148 along first major surface 104 and a ray extending from center of curvature 148 normal to first major surface 104. In other examples, the radius of curvature may be continuous, but not constant, such that the radius of curvature varies over a subtendedangle a of about 90 degrees. In such instances, center of curvature 148 will vary in position and may not be located at or on an exposed major surface of the laminated glass article.

[0095] In some embodiments, interlayer 132 of laminated glass article 400 may comprise a central portion, for example a central portion 150 (see FIG. 6), and a peripheral portion, such as peripheral portion 152, as described for laminated glass article 200. The peripheral portion 152 may comprise an elastic modulus greater than the elastic modulus of central portion 150. As used herein, the term “elastic modulus” means Young’s modulus measured at room temperature. Either one or both of first edge surface 108 or second edge surface 128 of laminated glass article 400 may comprise a non-constant radius of curvature over at least a portion of the one or both edge surfaces as described in respect of laminated glass article 300 (FIG. 6), wherein interlayer 132 extends over at least a portion of first glass substrate 102, second glass substrate 120, or both first and second glass substrates 102, 120.

[0096] FIGS. 8A-8B illustrate yet another embodiment of a laminated glass article 500 according to the present disclosure. Laminated glass article 500 comprises a first glass substrate 502, a second glass substrate 504, and an interlayer 506, for example a polymer interlayer, disposed between and joining the first and second glass substrates. More particularly, first glass substrate 502 comprises a first major surface 508 and a second major surface 510 opposite first major surface 508. First major surface 508 is joined to second major surface 510 by a first edge surface 514. First edge surface 514 comprises a continuous curvature with a first radius of curvature 516, for example a circular curvature (e.g., a bullnose profile) with a constant radius. First major surface 508 and second major surface 510 define a first thickness 512 therebetween along a normal to at least one of first major surface 508 or second major surface 510. First thickness 512 can be in a range from about 1.6 mm to about 6 mm, from about 1.7 mm to about 6 mm, from about 1.8 mm to about 6 mm, from about 1.9 mm to about 6 mm, from about 2 mm to about 6 mm, from about 2.1 mm to about 6 mm, from about 2.2 mm to about 6 mm, from about 2.3 mm to about 6 mm, from about 2.4 mm to about 6 mm, from about 2.5 mm to about 6 mm, from about 2.6 mm to about 6 mm, from about 2.8 mm to about 6 mm, from about 3 mm to about 6 mm, from about 3.2 mm to about 6 mm, from about 3.4 mm to about 6 mm, from about 3.6 mm to about 6 mm, from about 3.8 mm to about 6 mm, from about 4 mm to about 6 mm, from about 1.6 mm to about 5.8 mm, from about 1.6 mm to about 5.6 mm, from about 1.6 mm to about 5.5 mm, from about 1.6 mm to about 5.4 mm, from about 1.6 mm to about 5.2 mm, from about 1.6 mm to about 5 mm, from about 1.6 mm to about 4.8 mm, from about 1.6 mm to about 4.6 mm, from about 1.6 mm to about 4.4mm, from about 1.6 mm to about 4.2 mm, from about 1.6 mm to about 4 mm, from about 3.8 mm to about 5.8 mm, from about 1.6 mm to about 3.6 mm, from about 1.6 mm to about 3.4 mm, from about 1.6 mm to about 3.2 mm, or from about 1.6 mm to about 3 mm. In various embodiments, first major surface 508 may be parallel with second major surface 510 such that first thickness 512 is constant. However, in further embodiments, first thickness 512 may not be constant. For example, in some embodiments, first glass substrate may be wedge-shaped.

[0097] Likewise, second glass substrate 504 comprises a third major surface 518 and a fourth major surface 520 opposite third major surface 518. A second thickness 522, the thickness of second glass substrate 504, is defined between third major surface 518 and fourth major surface 520. Second glass substrate 504 further includes a second edge surface 524 joining third major surface 518 and fourth major surface 520. Second edge surface 524 may have a continuous curvature, for example a circular curvature with a constant second radius of curvature 526, e.g., a bullnose profile, although a constant radius of curvature is not required. For example, in some embodiments, the edge surface profile may be parabolic when viewed in cross-section on a plane orthogonal to one or both the first major surface or the second major surface. In various embodiments, second radius of curvature 526 may be less than first radius of curvature 516. Moreover, second thickness 522 may be less than first thickness 512. For example, second thickness 522 can be in a range from about 0.1 mm to less than about 1.6 mm, from about 0.1 mm to about 1.5 mm, from about 0.1 mm to about 1.4 mm, from about 0.1 mm to about 1.3 mm, from about 0. 1 mm to about 1.2 mm, from about 0.1 mm to about 1.1 mm, from about 0.1 mm to about 1 mm, from about 0.1 mm to about 0.9 mm, from about 0. 1 mm to about 0.8 mm, from about 0. 1 mm to about 0.7 mm, from about 0. 1 mm, from about 0.2 mm to equal to or less than about 1.6 mm, from about 0.3 mm to equal to or less than about 1.6 mm, from about 0.4 mm to equal to or less than about 1.6 mm, from about 0.5 mm to equal to or less than about 1.6 mm, from about 0.6 mm to equal to or less than about 1.6 mm, from about 0.7 mm to equal to or less than about 1.6 mm, from about 0.8 mm to equal to or less than about 1.6 mm, from about 0.9 mm to equal to or less than about 1.6 mm, or from about 1 mm to about 1.6 mm.

[0098] Interlayer 506 is disposed between first glass substrate 502 and second glass substrate 504 such that second major surface 510 of first glass substrate 502 is attached to first surface 528 of interlayer 506 and third major surface 518 of first glass substrate 502 is attached to second surface 530 of interlayer 506. Interlayer 506 may comprise any of the polymer materials previously described in preceding embodiments. Additionally, interlayer 506 may comprise one or more layers, including one or more tint layers, photochromic layers,electrochromic layers, or the like. Interlayer 506 includes a third thickness 532 defined between first surface 528 and second surface 530.

[0099] Laminated glass article 500 comprises a fourth thickness 534, an overall thickness of laminated glass article 500, defined between first major surface 508 and fourth major surface 520. Fourth thickness 534 can be 6.85 mm or less, or 5.85 mm or less, where the fourth thickness comprises the sum of first, second, and third thicknesses 512, 522 and 532 of first glass substrate 502, second glass substrate 504, and interlayer 506, respectively. In various embodiments, fourth thickness 534 can be in a range from about 1.8 mm to about 6.85 mm, or in a range of about 1.8 mm to about 5.85 mm, or in a range of about 1.8 mm to about 5.0 mm, or in a range from about 2. 1 mm to about 6.85 mm, or in a range from about 2. 1 mm to about 5.85 mm, or in a range from about 2. 1 mm to about 5.0 mm, or in a range from about 2.4 mm to about 6.85 mm, or in a range from about 2.4 mm to about 5.85 mm, or in a range from about 2.4 mm to about 5.0 mm, or in a range from about 3.4 mm to about 6.85 mm, or in a range from about 3.4 mm to about 5.85 mm, or in a range from about 3.4 mm to about 5.0 mm. In various embodiments, first major surface 508 may be parallel with fourth major surface 520 such that fourth thickness 534 is constant, although in further embodiments, fourth thickness 534 may vary. For example, a thickness of laminated glass article 500 may be wedge-shaped.

[0100] As best seen in FIG. 8B, showing an enlarged view of area A from FIG. 8A, interlayer 506 comprises a third edge surface 536 that joins first surface 528 and second surface 530. In various embodiments, third edge surface 536 is recessed relative to first edge surface 514 and second edge surface 524 such that first and second edge surfaces 514 and 524 (e.g., apexes thereof) extend beyond third edge surface 536. Accordingly, laminated glass article 500 comprises a composite edge surface 538, including first edge surface 514, second edge surface 524, and third edge surface 536, that is not a continuous curve with a constant radius of curvature. In the illustrated embodiments, laminated glass article 500 comprises first glass substrate 502 with a first bullnose edge profile, second glass substrate 504 with a second bullnose edge profile, and interlayer 506 disposed between the first and second glass substrates.

[0101] To avoid abrasion of seal material, the composite edge surface 538 can be coated with a low-friction coating material 540, for example an ultra-high molecular weight polymer (defined herein as a polymer material with a molecular weight of at least 106g / mole, for example greater than about 3xl06g / mole), or an easy-to-clean (ETC) material such as perfluoropolyether, to reduce friction between the composite edge surface and the seal material. However, a low-friction coating material may be applied to any of the various embodiments disclosed herein.

[0102] While not depicted herein, embodiments are also envisioned where the edge surface 144 of the interlayer 132 is flat (e.g., comprising a minimum radius of curvature greater than 10,000 mm) and connects arc segments formed by the edge surfaces 108 and 128. In such embodiments, the second glass substrate 120 can exhibit a 2.5D shape, where the fourth major surface 126 is non-planar towards the edges thereof. The edge surface 1298 can exhibit a relatively low radius of curvature in such 2.5D embodiments (e.g., less than or equal to 1.0 mm or eve less than or equal to 0.5 mm) with the laminate still exhibiting improved edge impact performance.

[0103] Embodiments of this disclosure can comprise a vehicle that includes one or more laminated glass articles described herein. For example, FIG. 9 shows a vehicle 600 comprising a body 602 defining an interior, at least one opening 604 in communication with the interior, and a glazing 606 disposed in the opening, wherein the glazing 606 comprises a laminated glass article, for example any of the laminated glass articles 100, 200, 300, 400, or 500 previously described. In one or more embodiments, the laminated glass article can be complexly curved. The laminated glass article may be movable against a seal material, for example a polymeric weather seal. The laminated glass article may form the sidelights (side windows, such as door windows), windshields, rear windows, rearview mirrors, and / or sunroofs in the vehicle. In some embodiments, the laminated glass article may form an interior partition (not shown) within the interior of the vehicle . A vehicle within the context of the present disclosure includes automobiles, motorcycles, rolling stock, locomotive, boats, ships, airplanes, helicopters, drones, space craft, and the like.

[0104] In one or more embodiments, the laminated glass article can be positioned within a vehicle such that the second glass substrate faces the interior of the vehicle and the first curved glass substrate faces the exterior. In some embodiments, the second glass substrate is in direct contact with the interior (e.g., the fourth major surface 126 or 520 of the second glass substrate 120 or 504, respectively, facing the interior may be bare and free of any coatings).

[0105] Edges of the laminated glass substrate can be formed by grinding. For example, the laminated glass article can be worked with a grinding wheel comprising one or more slots or channels, such as in an outer peripheral edge surface, having a predetermined shape. The resultant edge surface can be polished after grinding, if necessary. Alternatively, the edge surfaces of the glass substrates can be ground independently such that, when assembled and laminated together with the interlayer, yield the desired edge profile. In still other examples, the glass substrates and the interlayer can be temporarily joined, ground to the desired profile, then laminated together with a permanent bond.Examples

[0106] Various composite edge profiles of laminated glass articles were modeled using Abaqus 2D finite element analysis (FEA) software, to evaluate contact pressure against a compliant seal material. The coefficient of friction between the laminated glass article and the seal material (modeled to be in slab form) was assumed to be 0.3. The seal material was modeled using a Yeoh hyperelastic model with an initial modulus of elasticity of approximately 2MPa, whereas attributes of the laminated glass article were assumed as follows: the first (inner) glass substrate had a thickness of 3.5 mm, an elastic modulus of 72 GPa, a Poisson’s ratio of 0.22, and a density of 2440 kg / m3; the second (inner) glass substrate had a thickness of 1.1 mm, an elastic modulus of 73.3 GPa, a Poisson’s ratio of 0.21, and a density of 2450 kg / m3; the interlayer was assumed to be 0.76 mm thick, with an elastic modulus of 0.007 GPa, a Poisson’s ratio of 0.499, and a density of 1069 kg / m3. It was found that, while the interlayer plays a small part in the test results, modeling could be conducted by assuming the laminated glass article was a monolithic glass substrate. The testing was still indicative of relative performance and can be conducted more easily. That is, the laminated glass article, including the interlayer, was assumed to be a rigid homogeneous body with a selected edge profile and a singular coefficient of friction at the composite edge surface to understand the impact of edge profile on contact pressure against a simulated seal material. Additional modeling was conducted, however, to quantify the impact of the interlayer, which results are provided below.

[0107] As depicted in FIGS. 10A-10C, a modeled Seal Test was conducted wherein a laminated glass article 700 is assumed to be initially positioned on the seal material slab 702 with a bottom surface 704 of laminated glass article 700 in contact with the top surface 706 of the seal material (see FIG. 10A). Laminated glass article 700 is then forced down (arrows 708) into seal material 702 until top surface 710 of laminated glass article 700 is even with top surface 706 of seal material 702, e.g., 4 mm. Once top surface 710 of laminated glass article 700 and top surface 706 of seal material 702 were flush, laminated glass article 700 was modeled to move forward 100 mm at 50 mm / s, as represented by arrow 714 (FIG. 10C), then backwards 100 mm at 50 mm / s (FIG. 10D). This cycle was repeated for a total of three complete cycles for each edge profile. As shown in FIG. 10C, the forward motion of laminated glass article 700 results in a build-up 716 of seal material 702 in front of laminated glass article 700, increasing frictional forces on the glass substrate and increasing contact force on the seal material. The contact force at the end of the first forward excursion was used to evaluate several different edge profiles using this modeling technique. It was assumed seal materialwear is directly dependent on contact force. Accordingly, a lower contact force results in less seal material wear, all other factors being unchanged.

[0108] FIG. 11 shows an edge profile for a laminated glass article similar to that shown in FIG. 3 to which the above-described Seal Test was applied. The modeling shows significant deformation of the seal material where the glass substate edge contacts the seal material 702. This deformation is particularly notable in the recessed region 718 that would be formed in front of the interlayer, between the first and second glass substrates. Peak contact pressure for this embodiment during the Seal Test was 15.74 MPa.

[0109] FIG. 12 shows an edge profile for the laminated glass article of FIG. 4 subjected to the Seal Test. To wit, the composite edge surface of the laminated glass article exhibited a continuous curvature with a constant radius of curvature. The center of curvature was midway along the thickness of the laminated glass article (between the first and fourth glass substrate major surfaces). The modeling shows much less deformation of the seal material 702 than the embodiment shown in FIG. 11, although build-up of seal material forward of the composite edge surface is still visible. Peak contact pressure for this embodiment was 5.37 MPa, which was significantly less than for the embodiment of FIG. 11.

[0110] As noted above, the preceding modeling for FIG. 12 was conducted by assuming the glass laminate article was monolithic and homogeneous. To wit, the interlayer was assumed to have the same material characteristics as the glass substrates joined thereto. In reality, the modulus of elasticity of the interlayer is significantly less that the modulus of elasticity of the surrounding glass. When modeling was conducted accounting for the presence of a PVB interlayer and assuming a practical value for the interlayer elastic modulus (i.e., 0.007 GPa), the peak contact pressure for this embodiment increased to 8.47 MPa. Nevertheless, this increase still represented a significantly lower contact pressure than that for the embodiment of FIG. 11.

[0111] FIG. 13 shows a composite edge profile for a laminated glass article 300 similar to that shown in FIG. 6 and subjected to the Seal Test. The modeling shows deformation of seal material 702 similar to the deformation shown in FIG. 11, but with seal material 702 cresting over the top surface of the glass substrate (see arrow 720). Peak contact pressure for this embodiment during Seal Testing was about 4.35 MPa.

[0112] Additional modeling was also conducted to investigate the impact of coefficient of friction using an embodiment similar to FIGS. 8A-8B, as depicted in FIGS. 14A-14B. Four coefficient of friction values between the laminated glass article and the seal material were modeled: 0.3, 0.2, 0.1, and 0.05. The modeling assumed a thickness of 3.5 mm for the firstglass substrate, the interlayer had an assumed thickness of 0.76 mm, and the second glass substrate was assumed to have a thickness of 1.1 mm. The modeling yielded peak contact forces of 11.94 MPa, 7.8 MPa, 5.52 MPa, and 4.98 MPa, respectively, clearly showing contact force can be reduced by reducing the coefficient of friction between the glass laminate article and the seal material. Modeling results for a coefficient of friction of 0.3 (FIG. 14A) and 0.05 (FIG. 14B) are shown. Comparing the results of FIG. 14A and FIG. 14B, it can be clearly seen that reducing the coefficient of friction resulted in a significantly lower buildup of seal material forward of the composite edge surface and a commensurate reduction in contact pressure. Accordingly, and as shown in FIGS. 8A-8B, in some embodiments, the composite edge surface, regardless of profile shape, can be coated with a low-friction coating 540, for example an ultra-high molecular weight polymer or an ETC coating to reduce friction between the laminated glass article and damage to the seal material. That is, low-friction coating 540 can be applied to any of the embodiments disclosed herein.

[0113] To test impact resistance of composite edge profiles, the laminated glass articles were tested in accordance with a simulated Impact Test using a virtual impact testing apparatus 900 shown in FIG. 15. The virtual impact testing apparatus 900 comprised a pendulum arm 902 rotatable about axis of rotation 904 at proximal end 906, and a weight 908 coupled to a distal end 910 of pendulum arm 902. The length of the arm from the axis of rotation to the weight was 24 cm and the length of the weight was 3 cm, for an overall length of 27 cm. The impact testing apparatus 900 further comprised a support 912 to rigidly support a laminated glass article 914 on a surface thereof. A sample laminated glass article to be tested is placed on the support and secured to an upper surface of the support, such as by clamping, to prevent movement of the sample when contacted by weight 908. The sample is secured to the support with the edge to be tested facing up, opposite the support such that the weight, on a downward swing, contacts the edge to be tested. For the purpose of testing disclosed herein, the second glass substrate (i.e., the inside glass substrate, e.g., second glass substrate 120) was tested, and was placed facing upward. The pendulum arm was assumed to be raised to a drop angle (relative to horizontal) sufficient to provide a 0.264 Joule impact with the sample at an impact angle 0 of 30 degrees. The four types of laminated glass article samples were each modeled to include a second glass substrate thickness of 0.9 mm, an interlayer thickness of 0.76 mm, and a first glass substrate thickness of 3.5 mm. The second glass substrate was assumed to be Coming® Gorilla® glass (a chemically strengthened glass), the interlayer was PVB (polyvinylbutyral), and the first glass substrate was soda lime glass. The overhang distance 5 was assumed at 15 mm.

[0114] Four edge profiles for the inside glass substrate were modeled for impact resistance using the simulated impact test, (a) a flat, square-edged profile, (b) a chamfered edge profile, (c) a bullnose profile, and (d) an edge profile without continuous curvature. To emphasize, the bullnose profile in the context of this modeling refers to the shape of the second (inner) glass substrate, regardless of the shape of the first, outer glass substrate. Thus, bullnose in this regard represents a traditional edge profile, such as those depicted in FIGS. 2 and 3. Additionally, the continuous curvature refers to an embodiment such as shown in FIGS. 4-7. Outlines of the edge profiles are shown in FIG. 16a-d. Biaxial stress was determined computationally using finite element analysis as a function of time. The data shown in FIG. 17 provide a comparison of the maximum stress in the thin, inner substrate of the laminated glass when subjected to the impact. The data show that the edge profile with the non-bullnose continuous curvature (“quarter round”) had significantly lower peak stress that the other designs and thus the greatest resistance to impact damage, for example accidental impact that might occur on the upper edge portion of a half-open window.

[0115] To verify the simulation described above with respect to FIGS. 15-17, various laminates were constructed and physically tested. During the physical testing, the test apparatus 900 (see FIG. 15) comprised a cylindrical pendulum arm 902 having an outer diameter of 11 mm and length of 240 mm. The axis of rotation 904 was established at a center of a cylindrical rotating drum having an external diameter of 76 mm, to which the proximal end 906 was attached (at an outer surface of the rotating drum). The weight 908 was a 144 gram cylindrical body having a height (measured parallel to a lengthwise dimension of the pendulum arm 902) of 30 mm and an outer diameter of 24. 15 mm. The weight 908 was formed of stainless steel. Five different laminate constructions were tested, with the constructions being shown in the Table 1. “FT” represents fully tempered soda lime glass. “lOXed” represents chemically strengthened aluminosilicate glass (with a surface compressive stress greater than 750 MPa). “HS” represents heat-strengthened soda lime glass. As shown, four counter examples, where the laminates had the edge profile depicted in FIG. 2, were tested. An example having the construction depicted in FIG. 4 was also tested. Each construction included a 0.8 mm thick interlayer of acoustic PVB. Each constructed laminate had a size of 305 mm x 305 mm. Numerous samples of each construction were tested, and the mean impactenergy resulting in breakage of the impacted (thinner) substrate was recorded and the standard deviation was calculated. The results are provided in the Table 1.Table 1

[0116] As is revealed by comparing the results between CE3 and CE4, where the only difference in construction is that the second glass substrate 120 is chemically strengthened in CE4 and not chemically strengthened in CE3, the strengthening of the impacted second glass substrate 120 significantly improved the edge strength of the laminated glass article 100. Indeed, the mean impact energy resulting in breakage of the second glass substrate increased by almost an order of magnitude. As is further revealed by a comparison between CE4 and El, providing the laminated glass article 100 with the edge profile described herein provided further significant improvement in terms of impact performance. The only difference in laminate construction between CE4 and El was the continuously curved edge profile depicted in FIG. 4. The composite edge surface 142 in CE1 had a continuously curved surface with a constant radius of curvature between 2 mm and 3 mm. Such an edge surface improved the impact performance by over 60%, with a mean impact energy of over 1.0 J being required for breakage of the thinner glass substrate on average. Without wishing to be bound by theory, itis believed that this improved impact performance is the result of reduced bi-axial stresses resulting from the impact. It is believed that embodiments with more rigid outer plies than the fully tempered soda lime will exhibit slightly decreased impact energy values, while embodiments with less rigid outer plies will exhibit greater impact energy values.

[0117] It is believed that laminated articles provided with the edge profiles described herein will provide improved impact performance over laminates with similar constructions, but edges surfaces that are segmented, or with edge surfaces including an inflection point in a cross section thereof, such as the laminate constructions depicted in FIGS. 2 and 3. Irrespective of the thicknesses of the first glass substrate 102 and the second glass substrate 120, it is believed that providing a continuously curved edge profile without an inflection point will improve the impact performance (according to the test described herein using the apparatus 900) by at least 20%. As will be appreciated, the impact energy resulting in breakage will depend other factors, such as the thickness of the second glass substrate 120 and the degree of strengthening thereof (e.g., via ion exchange or heat strengthening). In some embodiments, laminated articles having a second glass substrate 120 with a thickness of 0.7 mm or greater and constructed of chemically strengthened aluminosilicate glass having a surface compressive stress of at least 600 MPa may exhibit a mean impact energy of greater than 0.30 J (e.g., greater than or equal to 0.33 J) inducing breakage, when tested via the same method as the Examples represented in the Table 1. Laminates with a second glass substrate 120 with a thickness of 0.9 mm or greater and having a surface compressive stress of at least 600 MPa may exhibit a mean impact energy of greater than 0.6 J inducing breakage. Laminates with a second glass substrate 120 with a thickness of 1.1 mm or greater and having a surface compressive stress of at least 600 MPa may exhibit a mean impact energy of greater than 0.75 J inducing breakage.

[0118] As the above results indicate, laminated articles with significantly improved edge impact performance can be provided even when using a relatively thin second glass substrate (the second thickness 130 is less than 1.5 mm in such embodiments) with some degree of strengthening being imparted on the glass substrate 120, such that the second glass substrate 120 comprises at least one layer of compressive stress extending from a surface thereof to a depth of the glass article and central portion under tensile stress. Such strengthening may be conducted thermally, chemically (e.g. via ion exchange), or mechanically (via constructing the second glass substrate 120 with a glass-on-glass laminate having a core layer and clad layers with different coefficients of thermal expansion to provide the layer of compressive stress). In embodiments, the second glass substrate 120 is strengthened to a greater degree than the first glass substrate 102 such that the second glass substrate 120 exhibits a higher surfacecompressive stress and maximum tensile stress than the first glass substrate 102. The improved edge impact performance is provided when the strengthening of the second glass substrate 120 is conducted after edge processing to form a portion of the composite edge surface 142 so that at least a portion of the composite edge surface 142 (corresponding to the edge surface of the second glass substrate 120) is under compressive stress. Such compressive stress on the edge surface is particularly advantageous when the laminated article 100 is implemented in a frameless side window, where the edge is particularly vulnerable to edge impacts.

[0119] In embodiments, the second glass substrate 120 is strengthened via ion exchange after the edge thereof is processed into a shape corresponding to the composite edge surface 142 described herein. It is believed that it may be beneficial to form the composite edge surface 142 by first forming a stack of the first glass substrate 102 and the second glass substrate 120. The stack may include a material attaching the first glass substrate 102 and the second glass substrate 120. In embodiments, the material is the material of the interlayer 132. In embodiments, the material is different from that of the interlayer 132 to facilitate detachment of the second glass substrate 120 from the first glass substrate 102 after the edge shaping. For example, the material may comprise a curable resin that is applied to one of the substrates in liquid form and subsequently cured after formation of the stack (e.g., via exposure to radiation, heating, or drying). After the stack is formed, the stack may be subjected to edge processing by a grinding wheel (or other suitable equipment) configured to remove material at the edge of the stack to form the composite edge surface 142 with a desired shape. In embodiments (e.g., when the material is that of the interlayer 132), the stack is constructed so that the material between the substrates is removed during the formation of the composite edge surface 142 so the material forms a portion of the composite edge surface 142. After a desired edge surface is formed via material removal, at least the second substrate 120 is strengthened. In embodiments, the entire stack is immersed in an ion exchange bath for a suitable immersion period (differences in compositions between the substrates may result in the second glass substrate 120 being strengthened to a greater extent than the first glass substrate 102). Both substrates could also be strengthened in the same bath after detachment of the first glass substrate 102 from the second glass substrate 120. In embodiments, the second glass substrate 120 is removed from the stack (e.g., by removal of the material between the substrates) and individually chemically strengthened. It is believed that embodiments where the second glass substrate 120 is individually strengthened are beneficial because the entire outer surface of the second glass substrate 120 is provided with a compressive stress, which may result in superior impact performance. Any of such processes generally result in at least the portion of thecomposite edge surface 142 made up by the second glass substrate 120 being chemically strengthened, providing improved edge impact performance. While the preceding description of strengthening and forming method was provided with respect to the laminated article, it should be understood that a similar methods could be applied to any of the other laminated articles 200, 300, 400, 500 described herein.

[0120] When any of the laminated articles 200, 300, 400, 500 is implemented as a side window the thicknesses of both the first and second glass substrates 102 and 120 may be greater than 0.5 mm. It has been found that a thickness of 0.5 mm for the inner glass substrate provides sufficient edge impact performance to provide a durable window. Moreover, providing the inner glass substrate with a greater degree of strengthening facilitates the side windows having improved impact performance, both from a reduced laceration potential from impacts from the internal side and external impacts (the strengthened second glass substrate 120, when facing a vehicle cabin, generally fractures into fragments that are less likely to cut the occupants or airbags then unstrengthened glass substrates). Asymmetric laminate constructions facilitate dissipation of energy from external impacts through flexure, while the greater degree of strengthening of the inner substrate prevents breakage of the window from such external impacts. Moreover, as described herein, provision of the edge surfaces described herein provides further enhancement from an edge impact perspective. Asymmetric laminated articles with the edge profiles described herein therefore provide improved impact performance on the outside, inside, and edge surfaces of the window.

[0121] With regard to the engagement of the edge surfaces described herein with seal material, limiting the minimum radius of curvature of any of the composite edge surfaces described herein is beneficial to reduce friction. In embodiments, any of the composite edge surfaces described herein may have a minimum radius of curvature that is greater than or equal to one quarter of the thickness of the thinner glass ply. In embodiments, any of the composite edge surfaces described herein. For example, in such embodiments, the minimum radius of curvature of the composite edge surface is greater than or equal to 0.1 mm„ greater than or equal to 0.2 mm, greater than or equal to 0.3 mm, greater than or equal to 0.4 mm, greater than or equal to 0.5 mm, greater than or equal to 0.6 mm, greater than or equal to 0.7 mm, greater than or equal to 0.8 mm, greater than or equal to 0.9 mm, greater than or equal to 1.0 mm, greater than or equal to 1.5 mm, or even greater than or equal to 2.0 mm. In embodiments, the portion of the composite edge that is constructed of the second glass substrate 120 (the second edge surface 128) comprises a minimum radius of curvature that is greater than or equal to 0.2 mm and less than or equal to 10,000 mm (e.g., greater than or equal to 0.5 mm and less than orequal to 100 mm, greater than or equal to 1.1 mm and less than or equal to 5.0 mm, greater than or equal to 1.2 mm and less than or equal to 5.0 mm, greater than or equal to 1.3 mm and less than or equal to 5.0 mm, greater than or equal to 1.4 mm and less than or equal to 5.0 mm, greater than or equal to 1 .5 mm and less than or equal to 5.0 mm, greater than or equal to 1.6 mm and less than or equal to 4.5 mm, greater than or equal to 1.7 mm and less than or equal to 4.0 mm, greater than or equal to 1.8 mm and less than or equal to 3.5 mm). Too high of a minimum radius of curvature can lead to the laminated article having sharp comers that increase friction with the seal material.

[0122] It should also be noted that, in side window applications, the interlayer 132 is generally formed of a compliant material to facilitate absorption of impact energy and retain fragments of the glass substrates together in the event that at least one of the glass substrates breaks upon impact. For example, if the first glass substrate 102 breaks, the interlayer 132 may retain the fragments of the first glass substrate 102 against the second glass substrate 120 to prevent fragments from dispersing from the vehicle. The interlayer 132 may generally have a modulus of elasticity that is greater than or equal to 1 MPa and less than or equal to 75 MPa (or even less than or equal to 30 MPa, or even less than or equal to 20 MPa, or even less than or equal 15 MPa, or even less than or equal to 10 MPa) to facilitate performance of such function. Unless otherwise noted herein, the terms “elastic modulus” or “modulus of elasticity” are used synonymously with Young’s modulus.

[0123] It will be apparent to those skilled in the art that various modifications and variations can be made to embodiments of the present disclosure without departing from the spirit and scope of the disclosure. Thus, it is intended that the present disclosure cover such modifications and variations provided they come within the scope of the appended claims and their equivalents.

Claims

What is claimed is:

1. A laminated glass article, comprising: a first glass substrate comprising a first major surface, a second major surface opposite the first major surface, a first edge surface joining the first major surface and the second major surface, and a first thickness extending between the first major surface and the second major surface; a second glass substrate comprising a third major surface, a fourth major surface opposite the third major surface, a second edge surface joining the third major surface and the second major surface, and a second thickness extending between the third major surface and the fourth major surface; and a polymer interlayer disposed between and joining with the second major surface and the third major surface, the polymer interlayer comprising an interlayer edge surface, wherein: the first thickness is greater than the second thickness, both the first thickness and the second thickness are greater than or equal to 0.5 mm, the second glass substrate comprises a maximum tensile stress that is greater than that of the first glass substrate as a result of being strengthened to a greater extent than the first glass substrate, and wherein a composite edge surface of the laminated glass article extends from the first major surface to the fourth major surface and includes the first edge surface, the second edge surface, and the interlayer edge surface, the composite edge surface defining an arc between the first major surface and the fourth major surface with a continuous curvature.

2. The laminated glass article of claim 1, wherein the arc comprises no inflection points.

3. The laminated glass article of claim 2, wherein the arc comprises a constant radius of curvature such that the arc is a circular arc.

4. The laminated glass article of claim 3, wherein: the arc comprises a center of curvature disposed within the first glass substrate or on the first major surface, and an entirety of the composite edge is disposed on the arc.

5. The laminated glass article of any of claims 1-4, wherein the arc comprises a minimum radius of curvature that is greater than or equal to a quarter of a total thickness of the laminated glass article.

6. The laminated glass article of claim 5, wherein the minimum radius of curvature is greater than or equal to 1.0 mm.

7. The laminated glass article of claim 5, wherein: the first thickness is greater than or equal to 2.5 mm and less than or equal to 6.0 mm, the second thickness is greater than or equal to 0.5 mm and less than or equal to 0.7 mm, and the interlayer comprises a thickness that is greater than or equal to 0.3 mm.

8. The laminated glass article of any of claims 1-7, wherein the interlayer has a modulus of elasticity ranging from 1 MPa to 75 MP.

9. The laminated glass article of claim 1, wherein the interlayer comprises a central portion comprising a peripheral edge and a peripheral portion extending outward from the peripheral edge, the peripheral portion contacting the first glass substrate and the second glass substrate and forming a portion of the composite edge surface.

10. The laminated glass article of claim 9, wherein a modulus of elasticity of the peripheral portion is greater than a modulus of elasticity of the central portion.

11. The laminated glass article of claim 1, wherein the composite edge surface is coated with a perfluoropolyether coating or a polymer coating with a molecular weight greater than about 106grams / mole.

12. The laminated glass article of claim 1, wherein, when an edge of the fourth major surface is impacted with a 144 g gram cylindrical stainless steel weight at an impact angle of 30° with an impact energy of 0.3 J, the second glass substrate does not fracture from the impact.

13. The laminated glass article of claim 12, wherein:the second thickness is greater than or equal to 0.9 mm and less than or equal to 1.5 mm and the second glass substrate is chemically strengthened such that the fourth major surface comprises a surface compressive stress greater than or equal to 600 MPa, and when the weight impacts the edge of the fourth major surface with an impact energy of 0.6 J, the second glass substrate does not break from the impact.

14. The laminated glass article of claim 12, wherein: the second thickness is greater than or equal to 1. 1 mm and less than or equal to 1.5 mm and the second glass substrate is chemically strengthened such that the fourth major surface comprises a surface compressive stress greater than or equal to 600 MPa, and when the weight impacts the edge of the fourth major surface with an impact energy of 0.75 J, the second glass substrate does not break from the impact.

15. The laminated glass article of any one of claims 1-14, wherein an entirety of the second edge surface is under compressive stress.

16. A laminated glass article, comprising: a first glass substrate comprising a first major surface, a second major surface opposite the first major surface, a first edge surface joining the first major surface and the second major surface, and a first thickness extending between the first major surface and the second major surface; a second glass substrate comprising a third major surface, a fourth major surface opposite the third major surface, a second edge surface joining the third major surface and the second major surface, and a second thickness extending between the third major surface and the fourth major surface; and a polymer interlayer disposed between and joining with the second major surface and the third major surface, the polymer interlayer comprising an interlayer edge surface, wherein: the laminated glass article comprises a total thickness extending between the first major surface and the fourth major surface, the total thickness being greater than or equal to 1 .8 mm and less than or equal to 6.85 mm, a composite edge surface of the laminated glass article extends from the first major surface to the fourth major surface and includes the first edge surface, the second edge surface, and the interlayer edge surface, the composite edge surface defining an arc between the first major surface and the fourth major surface with a continuous curvature, andthe arc comprises a minimum radius of curvature that is greater than or equal to the total thickness.

17. The laminated glass article of claim 16, wherein the arc comprises no inflection points.

18. The laminated glass article of claim 17, wherein the arc comprises a constant radius of curvature such that the arc is a circular arc.

19. The laminated glass article of claim 18, wherein the arc comprises a center of curvature disposed within the first glass substrate or on the first major surface.

20. The laminated glass article of any of claims 16-19, wherein the minimum radius of curvature is greater than or equal to 1.0 mm.

21. The laminated glass article of any of claims 16-20, wherein: the first thickness is greater than or equal to 2.5 mm and less than or equal to 6.0 mm, the second thickness is greater than or equal to 0.5 mm and less than or equal to 0.7 mm, and the interlayer comprises a thickness that is greater than or equal to 0.3 mm.

22. The laminated glass article of any of claims 16-21, wherein the interlayer has a modulus of elasticity ranging from 1 MPa to 75 MP.

23. The laminated glass article of claim 16, wherein the interlayer comprises a central portion comprising a peripheral edge and a peripheral portion extending outward from the peripheral edge, the peripheral portion contacting the first glass substrate and the second glass substrate and forming a portion of the composite edge surface.

24. The laminated glass article of claim 23, wherein a modulus of elasticity of the peripheral portion is greater than a modulus of elasticity of the central portion.

25. The laminated glass article of claim 16, wherein the composite edge surface is coated with a perfluoropolyether coating or a polymer coating with a molecular weight greater than about 106grams / mole.

26. The laminated glass article of claim 16, wherein: when an edge of the fourth major surface is impacted with a 144 g gram cylindrical stainless steel weight at an impact angle of 30° with an impact energy of 0.3 J, the second glass substrate does not fracture from the impact, and the second glass substrate comprises a maximum tensile stress that is greater than that of the first glass substrate as a result of being strengthened to a greater extent than the first glass substrate27. The laminated glass article of claim 26, wherein: the second thickness is greater than or equal to 0.9 mm and less than or equal to 1.5 mm and the second glass substrate is chemically strengthened such that the fourth major surface comprises a surface compressive stress greater than or equal to 600 MPa, and when the weight impacts the edge of the fourth major surface with an impact energy of 0.6 J, the second glass substrate does not break from the impact.

28. The laminated glass article of claim 26, wherein: the second thickness is greater than or equal to 1. 1 mm and less than or equal to 1.5 mm and the second glass substrate is chemically strengthened such that the fourth major surface comprises a surface compressive stress greater than or equal to 600 MPa, and when the weight impacts the edge of the fourth major surface with an impact energy of 0.75 J, the second glass substrate does not break from the impact.

29. The laminated glass article of any one of claims 16-28, wherein an entirety of the second edge surface is under compressive stress.

30. A laminated glass article, comprising: a first glass substrate comprising a first major surface, a second major surface opposite the first major surface, and a first edge surface joining the first major surface and the second major surface; a second glass substrate comprising a third major surface, a fourth major surface opposite the third major surface, and a second edge surface joining the third major surface and the second major surface;a polymer interlayer disposed between and joining with the second major surface and the third major surface; and wherein a composite edge surface of the laminate glass article extends from the first major surface to the fourth major surface and includes the first edge surface, the second edge surface, and an edge surface of the polymer interlayer, the composite edge surface formed by the first edge surface of the first glass substrate, the second edge surface of the second glass substrate, and an edge surface of the interlayer, the composite edge surface coated with a perfluoropolyether coating or a polymer coating with a molecular weight greater than about 106grams / mole.

31. The laminated glass article of claim 30, wherein the composite edge surface defines an arc between the first major surface and the second major surface with a continuous curvature.

32. The laminated glass article of claim 31, wherein the arc comprises no inflection points.

33. The laminated glass article of claim 32, wherein the arc comprises a constant radius of curvature such that the arc is a circular arc.

34. The laminated glass article of claim 33, wherein the arc comprises a center of curvature disposed within the first glass substrate or on the first major surface.

35. The laminated glass article of any one of claims 30-34, wherein the composite edge surface comprises a minimum radius of curvature that is greater than or equal to one fourth of a total thickness of the laminated class article, wherein the total thickness is greater than or equal to 1.8 mm and less than or equal to 1.5 mm.

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