Glassware and in-vehicle display devices

Abstract

The present invention relates to a glass article (10) having: a protective glass (12); and a frame (14) attached to the main surface (12B) of the protective glass (12) via an adhesive layer (16); and the protective glass (12) having a curved portion convex toward the main surface (12B); the adhesive layer (16) comprising at least one of a first adhesive layer and a second adhesive layer; and the thickness of the protective glass, Young's modulus, perimeter, radius of curvature of the curved portion, and area of ​​the adhesive layer having a specific relationship.

Description

Technical Field

[0001] This invention relates to a glass article and a display device for use in a vehicle. Prior Technology

[0002] In vehicle-mounted display devices that display information required during driving, liquid crystal displays (LCDs) or organic EL displays are sometimes used. In these displays, protective glass is sometimes installed to protect the front. Furthermore, in recent years, there has been a growing demand for more sophisticated interior design in vehicles, requiring protective glass with curved shapes. As one method for bending protective glass, the cold forming method, such as that described in Patent Document 1, is already known. [Preliminary Technology Documents] [Patent Literature]

[0003] Patent Document 1: Japanese Patent Publication No. 2017-532233 Summary of the Invention

[0004] [The problem the invention aims to solve]

[0005] However, protective glass that is bent into shape by means of, for example, cold forming, maintains its curved shape by fixing the protective glass to the frame with adhesive, so there is a risk that the protective glass may peel off from the frame due to springback.

[0006] The present invention was made in view of the above-mentioned problems, and its purpose is to provide a glass article and a vehicle display device that can prevent the protective glass from peeling off from the frame. [Technical means to solve the problem]

[0007] In order to solve the above problems and achieve the purpose, the glass article disclosed herein has: a protective glass having a first main surface and a second main surface; and a frame having a frame attached to the second main surface of the protective glass via an adhesive layer; and the protective glass having a curved portion convex to the second main surface; the adhesive layer includes at least one of a first adhesive layer having an elastic modulus of 5 MPa or more in an indentation elastic modulus test and a second adhesive layer having an elastic modulus of less than 5 MPa in an indentation elastic modulus test; when R' is set as shown in the following formula (1) and C1 is set as shown in the following formula (2), the curved portion satisfies the following formula (3) when C1>0 and satisfies the following formula (4) when C1≦0.

[0008] Here, R in the following formula is the radius of curvature (mm) of the aforementioned curved portion; F is the length of the aforementioned flat area in the aforementioned first direction when the aforementioned protective glass has a flat area adjacent to the first direction orthogonal to the bending axis of the aforementioned curved portion; t is the thickness (mm) of the aforementioned protective glass; A1 is the area (mm2) of the aforementioned first bonding layer in the aforementioned curved portion; A2 is the area (mm2) of the aforementioned second bonding layer in the aforementioned curved portion; E is the Young's modulus (GPa) of the aforementioned protective glass; L refers to the length (mm) of the aforementioned curved portion in the aforementioned first direction.

[0009] [Number 1]

[0010] [Number 2]

[0011] [Number 3]

[0012] [Number 4]

[0013] In order to solve the above problems and achieve the purpose, the glass article disclosed herein has: a protective glass having a first main surface and a second main surface; and a frame having a frame attached to the second main surface of the protective glass via an adhesive layer; and a curved portion having a convex shape toward the first main surface of the protective glass; the adhesive layer includes at least one of a first adhesive layer having an elastic modulus of 5 MPa or more in an indentation elastic modulus test and a second adhesive layer having an elastic modulus of less than 5 MPa in an indentation elastic modulus test; when R' is set as shown in the following formula (1) and C2 is set as shown in the following formula (5), the curved portion satisfies the following formula (6) when C2>0 and satisfies the following formula (7) when C2≦0.

[0014] Here, R in the following formula is the radius of curvature (mm) of the aforementioned curved portion; F is the length of the aforementioned flat area in the aforementioned first direction when the aforementioned protective glass has a flat area adjacent to the first direction orthogonal to the bending axis of the aforementioned curved portion; t is the thickness (mm) of the aforementioned protective glass; A1 is the area (mm2) of the aforementioned first bonding layer in the aforementioned curved portion; A2 is the area (mm2) of the aforementioned second bonding layer in the aforementioned curved portion; E is the Young's modulus (GPa) of the aforementioned protective glass; L refers to the length (mm) of the aforementioned curved portion in the aforementioned first direction.

[0015] [Number 5]

[0016] [Number 6]

[0017] [Number 7]

[0018] [Number 8]

[0019] In order to solve the above problems and achieve the purpose, the vehicle-mounted display device disclosed herein includes: a display screen and the aforementioned glass article disposed on the surface of the aforementioned display screen. [Effects of the Invention]

[0020] According to the present invention, the peeling of the protective glass from the frame can be suppressed. Simple Explanation of the Diagram

[0021] Figure 1 is a schematic diagram showing the vehicle-mounted display device of this embodiment. Figure 2 is a schematic diagram of a glass article according to this embodiment. Figure 3 is a top view of the protective glass. Figure 4 is a cross-sectional view of the protective glass. Figure 5 is an example of a graph illustrating the relationship between the properties of protective glass. Figure 6 shows an example of a scenario where both a first adhesive layer and a second adhesive layer are provided. Figure 7 is a schematic diagram of protective glass in another example of this embodiment. Figure 8 is a schematic diagram of another example of protective glass in this embodiment. Figure 9 is a schematic diagram of protective glass, another example of this embodiment. Figure 10 is a schematic diagram of protective glass in another example of this embodiment. Figure 11 is a schematic diagram of another example of protective glass in this embodiment. Figure 12 is a schematic diagram of another example of protective glass in this embodiment. Figure 13 is a schematic diagram of protective glass in another example of this embodiment. Figure 14 is a schematic diagram of another example of protective glass in this embodiment. Figure 15 is a schematic diagram of another example of protective glass in this embodiment. Figure 16 is a schematic diagram of protective glass, another example of this embodiment. Figure 17 is a schematic diagram of another example of protective glass in this embodiment. Figure 18 is a schematic diagram of protective glass, another example of this embodiment. Figure 19 is a schematic diagram of protective glass, another example of this embodiment. Figure 20 is a schematic diagram of protective glass, another example of this embodiment. Figure 21 is a graph showing the evaluation results of each protective glass in Examples 1 and 2. Figure 22 is a graph showing the evaluation results of each protective glass in Examples 3 and 4. Figure 23 is a graph showing the evaluation results of the protective glass in Examples 5 and 6. Figure 24 is a graph showing the evaluation results of the protective glass in Examples 7 and 8. Figure 25 is a graph showing the evaluation results of the protective glass in Examples 9 and 10. Figure 26 is a graph showing the evaluation results of the protective glass in Examples 11 and 12. Figure 27 is a graph showing the evaluation results of the protective glass in Examples 13 and 14. Figure 28 is a graph showing the evaluation results of the protective glass in Examples 15 and 16. Figure 29 is a graph showing the evaluation results of the protective glass in Examples 17 and 18. Figure 30 is a graph showing the evaluation results of each protective glass in Examples 19 and 20. Figure 31 is a graph showing the evaluation results of the protective glass in Examples 21 and 22. Figure 32 is a graph showing the evaluation results of the protective glass in Examples 23 and 24. Figure 33 is a graph showing the evaluation results of the protective glass in Examples 25 and 26. Figure 34 is a graph showing the evaluation results of the protective glass in Examples 27 and 28. Figure 35 is a graph showing the evaluation results of the protective glass in Examples 29 and 30. Figure 36 is a graph showing the evaluation results of the protective glass in Examples 31 and 32. Figure 37 is a graph showing the evaluation results of the protective glass in Examples 33 and 34. Figure 38 is a graph showing the evaluation results of the protective glass in Examples 35 and 36. Figure 39 is a graph showing the evaluation results of the protective glass in Examples 37 and 38. Figure 40 is a graph showing the evaluation results of the protective glass in Examples 39 and 40. Figure 41 is a graph showing the evaluation results of the protective glass in Examples 41 and 42. Figure 42 is a graph showing the evaluation results of the protective glass in Examples 43 and 44. Implementation

[0022] Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail. Furthermore, the present invention is not limited to these embodiments, and in the case of multiple embodiments, it also includes combinations of various embodiments. Also, for numerical values, rounding is included.

[0023] (Vehicle-mounted display device) Figure 1 is a schematic diagram showing the vehicle-mounted display device of this embodiment. As shown in Figure 1, the glass article 10 of this embodiment is disposed on the vehicle-mounted display device 2 and is used as a protective material for the surface (front) of the display screen 3 for displaying images.

[0024] The in-vehicle display device 2 is a display device installed in a vehicle, for example, inside the vehicle, in front of the steering shaft 1. The display 3 shows various instruments such as a car navigation screen or speedometer, as well as the start button. However, the configuration in Figure 1 is only one example; the in-vehicle display device 2 using the glass object 10 can be configured arbitrarily. Furthermore, the glass object 10 is not limited to being used as a protective material for the surface of the in-vehicle display device 2; it can be used for any purpose.

[0025] (Glass items) Figure 2 is a schematic diagram of the glass article of this embodiment. As shown in Figure 2, the glass article 10 includes a protective glass 12, a frame 14, and an adhesive layer 16. The protective glass 12 is a transparent, plate-shaped glass component, having a main surface 12A (first main surface) on one side and a main surface 12B (second main surface) on the opposite side of the main surface 12A. When the glass article 10 is mounted on a vehicle-mounted display device 2 or other mounted object, the main surface 12A of the protective glass 12 is the side exposed to the outside, and the main surface 12B is the side facing the mounted object (here, the display 3). Furthermore, "transparent" here means that visible light can pass through.

[0026] The frame 14 is a frame-shaped component mounted on the main surface 12B of the protective glass 12. The frame 14 is made of, for example, resin or metal, but is not limited to these materials and can be formed from any material. Since the protective glass 12 is bent in the X direction (first direction) as described later, the frame 14 is also bent along the protective glass 12 in the X direction. The frame 14 is mounted on the periphery of the main surface 12B of the protective glass 12.

[0027] In the example of Figure 2, although the frame 14 spans the entire circumferential area of ​​the periphery of the main surface 12B of the protective glass 12, it is not limited to this and may be interrupted in a portion of the area. Also, in the example of Figure 2, the peripheral end of the protective glass 12 protrudes from the frame 14, but it is not limited to this and the peripheral end of the protective glass 12 may protrude from the frame 14.

[0028] In the example of Figure 2, the frame 14 is disposed around the periphery of the protective glass 12 and is a frame-shaped structure with an inner opening, but it can also be a box-shaped structure with no opening. That is, a plate-shaped component covering the opening can be provided on the Z-direction side of the frame 14 in Figure 2. Thus, the shape of the frame 14 and the mounting position in the main surface 12B are not limited to the above description and can be arbitrary.

[0029] The frame 14 is fixed (attached) to the main surface 12B of the protective glass 12 via the adhesive layer 16. That is, the adhesive layer 16 is disposed between the frame 14 and the main surface 12B of the protective glass 12, attaching the surface of the frame 14 on the protective glass 12 side to the main surface 12B of the protective glass 12. The adhesive layer 16 can be constructed of any adhesive component that can attach the frame 14 and the protective glass 12, such as double-sided tape or adhesive.

[0030] The glass article 10 includes at least one of a first adhesive layer and a second adhesive layer as adhesive layer 16. The first adhesive layer refers to an adhesive layer with an elastic modulus of 5 MPa or higher in an indentation modulus test, and the second adhesive layer refers to an adhesive layer with an elastic modulus of less than 5 MPa in an indentation modulus test. That is, the indentation modulus of the first adhesive layer is higher than that of the second adhesive layer. Preferably, the first adhesive layer has an elastic modulus of less than 100 MPa in the indentation modulus test, more preferably less than 30 MPa. Here, the elastic modulus of the first contact layer in the indentation modulus test is preferably 5 MPa or higher and less than 100 MPa, more preferably 5 MPa or higher and less than 30 MPa. The elastic modulus of the second adhesive layer in the indentation modulus test is preferably 0.2 MPa or higher, more preferably 0.5 MPa or higher. Here, the elastic modulus of the second contact layer in the indentation elastic modulus test is preferably 0.2 MPa or higher but less than 5 MPa, and more preferably 0.5 MPa or higher but less than 5 MPa.

[0031] The first and second bonding layers are composed of different bonding members. The bonding members constituting the first bonding layer have a higher bonding strength than the bonding members constituting the second bonding layer. Furthermore, the bonding layer 16 can be composed of three or more types of bonding members.

[0032] Furthermore, the indentation modulus test of this embodiment is conducted using the following method. The adhesive layer 16, which is attached to the main surface 12B of the protective glass 12 and the frame 14, is exposed vertically upward and disposed in a creep meter (e.g., Sanden Corporation model RE2-33005C). For the adhesive layer 16, at room temperature, for example 20°C and relative humidity of 50%, a plunger (e.g., Sanden Corporation cylindrical plunger model P-61, ϕ1.5, H40) is pressed in at a pressing speed of 0.05 mm / s until the pressing depth is 5% to 10% of the thickness of the adhesive layer 16.

[0033] There are no particular limitations on the way the adhesive layer is exposed, but a method that does not affect the properties of the adhesive is preferred. For example, a method that physically peels the adhesive layer apart by inserting a thin metal plate between the first adhesive layer and the substrate, i.e., the protective glass 12 or the frame 14. In the event that the adhesive layer breaks off midway in the thickness direction during peeling, it is preferable to measure the elastic modulus of the thicker portion remaining. Furthermore, it is preferable to use the adhesive layer remaining on the side of the frame 14 and the protective glass 12 with a higher Young's modulus to determine the modulus of elasticity. That is, it is preferable to leave the adhesive layer on the frame side when the frame is made of metal, and leave the adhesive layer on the protective glass side when the frame is made of resin with a lower Young's modulus, and then determine the modulus of elasticity.

[0034] Secondly, the load acting on the plunger during each indentation and the displacement in the indentation direction are measured sequentially. The load and displacement are plotted hourly, and the slope of the fitted line at each plotted point is calculated as the elastic modulus of the adhesive layer 16. This indentation elastic modulus test is performed at each location of the adhesive layer 16. Areas with an elastic modulus of 5 MPa or higher are designated as the first adhesive layer, and areas with an elastic modulus below 5 MPa are designated as the second adhesive layer. Furthermore, it is preferable to plot every 0.04 seconds, performing two indentation elastic modulus tests at each location. The location with an elastic modulus of 5 MPa or higher from the two measurements can be designated as the first adhesive layer, and the location with an elastic modulus below 5 MPa from the two measurements can be designated as the second adhesive layer.

[0035] Here, the meaning of the indentation modulus test of the present invention will be explained. In glass articles, an adhesive bonds the glass surface, or the printed surface of the glass surface, to a frame made of metal or resin. In cases where it is intended to peel the bonded glass surface from the bonded object, the adhesive is generally designed so that it peels off by breaking. Moreover, it is known that the adhesive strength at the time of adhesive breakage depends on the tensile modulus of elasticity of the adhesive. However, existing adhesive strength tests, such as the cross-shaped adhesive strength test or the H-shaped adhesive strength test, are difficult to measure in glass articles where the protective glass is bonded to the frame. In the present invention, the indentation modulus test, which can also be verified in glass articles where the protective glass is bonded to the frame, is used as an evaluation method to replace existing adhesive strength tests. In this invention, since it is known that the adhesive breaks when the glass article is peeled from the frame, and the tensile modulus of elasticity and the indentation modulus of elasticity generally have a positive correlation, it is speculated that the adhesion strength is also related to the modulus of elasticity in the indentation test.

[0036] (Protective Glass) The protective glass 12 is bent and installed in the frame 14. In this embodiment, the flat glass sheet of the protective glass 12 is bent by cold forming and installed in the frame 14. That is, the protective glass 12 is installed in the frame 14 under bending stress. Hereinafter, the protective glass 12 will be described in more detail. In addition, cold forming here means a process of bending the glass into the desired shape without raising the temperature of the glass to its softening point.

[0037] (The shape of the protective glass) Figure 3 is a top view of the protective glass, and Figure 4 is a cross-sectional view of the protective glass. In the example of Figure 3, the protective glass 12 is a rectangular flat glass plate that has been bent. Hereinafter, one side (end face) of the protective glass 12 will be designated as side 12C1, the side opposite to side 12C1 will be designated as side 12C2, the other side of the protective glass 12 will be designated as side 12C3, and the side opposite to side 12C3 will be designated as side 12C4.

[0038] In the example of Figure 3, sides 12C1 and 12C2 are the shorter sides of a rectangle, and sides 12C3 and 12C4 are the longer sides of a rectangle. Furthermore, the protective glass 12 is not limited to a curved shape of a rectangular flat glass plate; it can be a curved glass plate of any shape. For example, the protective glass 12 can be a curved shape of a polygonal, circular, or elliptical flat glass plate.

[0039] (The curvature of the protective glass) Figure 3 is a view of the protective glass 12 viewed from the normal direction (Z direction) of position P on the main surface 12B of the protective glass 12. Figure 4 shows the cross section S of the protective glass 12 along the X direction.

[0040] Here, the tangent direction selected from the tangent directions of any point P on the main surface 12B of the protective glass 12, in a manner that satisfies the following conditions, is designated as the X direction (first direction). The direction orthogonal to the X direction among the tangent directions of the main surface 12B of point P is designated as the Y direction. The direction orthogonal to both the X and Y directions, i.e., the normal direction (thickness direction) of position P, is designated as the Z direction. Here, the X direction refers to the direction with the smallest radius of curvature of the line formed by the intersection of the plane containing both the tangent and normal directions of the tangent directions of the main surface 12B of any point P on the main surface 12B of the protective glass 12 with the main surface 12B.

[0041] Since the protective glass 12 in this embodiment is uniaxially bent, the X direction can be fundamentally defined regardless of the location P. However, sometimes, as in another example described later, a plurality of bends 20 are provided, and the bending directions of each bend 20 intersect. In this case, it is sufficient to define the X direction for each bend 20. That is, the direction with the smallest radius of curvature of the line formed by the intersection of the plane containing the tangent direction and the normal direction of the tangent direction at location P on a bend 20 and the main surface 12B can be defined as the X direction of that bend 20, and the X direction can be defined similarly for each bend 20. Furthermore, if there are multiple tangent directions that have the smallest radius of curvature for the line formed by the intersection of a plane containing both tangent and normal directions with the principal surface 12B, at least one of these tangent directions can be designated as the X direction. Hereinafter, the radius of curvature of the line formed by the intersection of a plane containing both X and Z directions with the principal surface 12B will be referred to as the radius of curvature R1.

[0042] The protective glass 12 is bent with the Y-axis as the bending axis and the X-axis as the direction orthogonal to the bending axis, and is bent with a radius of curvature R. The radius of curvature R of the protective glass 12 (the radius of curvature of the bend with the Y-axis as the bending axis) is preferably 50 mm to 10,000 mm, more preferably 100 mm to 5,000 mm, and most preferably 200 mm to 3,000 mm. By using a radius of curvature R within this range, design flexibility can be improved, and peeling from the frame can be suppressed. Furthermore, the radius of curvature can be, for example, 2,000 mm or less, 1,750 mm or less, 1,500 mm or less, 12,250 mm or less, or 1,000 mm or less. If the radius of curvature is within this range, peeling from the frame, which was previously prone to occur, can be significantly suppressed by satisfying the formula of this invention.

[0043] The protective glass 12 is preferably not bent in any direction other than the bending direction with the Y direction as the bending axis. The protective glass 12 is preferably not bent with the X direction as the bending axis; in other words, the trajectory along the Y direction on the main surface 12B of the protective glass 12 is preferably straight. Furthermore, the absence of bending is not limited to an infinite radius of curvature, but may include radii of curvature greater than 10,000 mm. By bending in any direction other than the Y direction as described above, the protective glass 12 can be planarized and appropriately cold-formed.

[0044] Hereinafter, the portion of the protective glass 12 that bends along the Y-axis will be referred to as the curved portion 20. The curved portion 20 refers to the area of ​​the protective glass 12 that bends along the Y-axis with the same radius of curvature R. That is, the curved portion 20 of the protective glass 12 can be described as bending with radius of curvature R and along the Y-axis. In the example of Figure 4, since the entire protective glass 12 bends along the X-axis with the same radius of curvature R, the entire protective glass 12 can be considered as the curved portion 20. Furthermore, the radius of curvature R is the same here, but it is not limited to the radius of curvature R being exactly the same at every position. For example, if the change in radius of curvature R measured at each position on the main surface 12B of the protective glass 12, in a region bent with the Y direction as the bending axis, from one end point in the X direction to the other end point, is less than 5%, that is, if the difference between the maximum and minimum values ​​of the radius of curvature R at each position is less than 5% of the maximum value of the radius of curvature R at each position, then this region is considered as a region with the same radius of curvature and treated as a single curved section 20. Alternatively, the average value of the radius of curvature R at each position of the curved section 20 can be used as the radius of curvature R of the curved section 20.

[0045] Examples of methods for measuring the radius of curvature R of the protective glass 12 include: using a contact or non-contact three-dimensional measuring machine to measure the shape and obtaining the value based on the shape data; or pressing an R ruler against the protective glass 12 to measure the radius of curvature.

[0046] In this embodiment, the bent portion 20 is bent in such a way that it protrudes from the main surface 12A side. However, the bent portion 20 is not limited to being bent in such a way that it protrudes from the main surface 12A side, but can be bent in such a way that it protrudes from the main surface 12B side.

[0047] Furthermore, any point P mentioned above refers to any point within the curved portion 20 of the main surface 12B. For example, in the case where the central region of the main surface 12A is the curved portion 20, it can be the center position of the main surface 12B (e.g., the center of gravity of the protective glass 12). That is, the X and Y directions can be the tangent directions from the center of the main surface 12B, and the Z direction can be the normal direction from the center of the main surface 12B.

[0048] (Length of the curved section) The length of the curved portion 20 in the X direction, which is orthogonal to the bending axis, is defined as the perimeter L. The perimeter L refers to the length of the line on the main surface 12B that connects the endpoint (position) on one side of the curved portion 20 in the X direction to the endpoint (position) on the other side of the curved portion 20 in the X direction and faces the X direction.

[0049] The line on the main surface 12B pointing towards the X direction refers to a line along the main surface 12B that is not offset towards the Y direction and points towards the X direction. In the example of Figure 3, since the endpoint of the curved portion 20 in the X direction is a point on the side surface 12C1, and the endpoint of the curved portion 20 in the X direction is a point on the side surface 12C2, the perimeter L refers to the length of the line on the main surface 12B pointing towards the X direction from the side surface 12C1 to the side surface 12C2.

[0050] The perimeter L is preferably 100 mm to 2000 mm, more preferably 150 mm to 700 mm, and most preferably 200 mm to 400 mm. Specifically, the perimeter L is preferably 100 mm or more, more preferably 150 mm, and most preferably 200 mm or more; furthermore, it is preferably 2000 mm or less, more preferably 700 mm or less, and most preferably 400 mm or less. By using a perimeter L within this range, design flexibility can be improved, and peeling from the frame can be suppressed. Furthermore, in this embodiment, even if the area has the same radius of curvature R, areas with a perimeter L of 5 mm or less (such as surface irregularities or minor undulations) are not treated as curved portions 20. That is, areas with the same radius of curvature R and a perimeter L longer than 5 mm are designated as curved portions 20.

[0051] The length of the bending axis (Y direction) of the bent portion 20 is preferably 80 mm to 500 mm, more preferably 100 mm to 400 mm, and most preferably 120 mm to 300 mm. Here, the length in the Y direction is preferably 80 mm or more, more preferably 100 mm or more, and most preferably 120 mm or more; furthermore, it is preferably 500 mm or less, more preferably 400 mm or less, and most preferably 300 mm or less.

[0052] Furthermore, the length of the curved portion 20 in the Y direction refers to the length of the line on the main surface 12B that connects the endpoint (position) on one side of the curved portion 20 in the Y direction to the endpoint (position) on the other side of the curved portion 20 in the Y direction and faces the Y direction. Furthermore, the line on the main surface 12B pointing towards the Y direction refers to a line along the main surface 12B that is not offset towards the X direction and points towards the Y direction. In the example of Figure 3, since each point is a point on the side surfaces 12C3 and 12C4, the length of the curved portion 20 in the Y direction refers to the length of the line on the main surface 12B pointing towards the Y direction from the side surface 12C3 to the side surface 12C4.

[0053] (Thickness of protective glass) The thickness t of the protective glass 12 is preferably 0.3 mm to 3.0 mm, more preferably 0.4 mm to 1.5 mm, and most preferably 0.6 mm to 1.3 mm. Here, the thickness t is preferably 0.3 mm or more, more preferably 0.4 mm or more, and most preferably 0.6 mm or more; furthermore, it is preferably 3.0 mm or less, more preferably 1.5 mm or less, and most preferably 1.3 mm or less. By using a thickness t within this range, design flexibility can be improved, and peeling from the frame can be suppressed. Furthermore, the thickness t refers to the distance in the Z direction from the main surface 12A to the main surface 12B.

[0054] (Young's Modulus for Protective Glass) The Young's modulus E of the protective glass 12 is preferably 60 GPa to 90 GPa, more preferably 68 GPa to 78 GPa, and most preferably 72 GPa to 76 GPa. Here, the Young's modulus E is preferably 60 GPa or higher, more preferably 68 GPa or higher, and most preferably 72 GPa; furthermore, it is preferably 90 GPa or lower, more preferably 78 GPa or lower, and most preferably 76 GPa or lower. By using the Young's modulus E within this range, design flexibility can be improved, and peeling from the frame can be suppressed.

[0055] (Materials for Protective Glass) The material of the glass used for the protective glass 12 is arbitrary, but for example, alkali-free glass, soda-lime glass, soda-lime silicate glass, aluminosilicate glass, borosilicate glass, lithium aluminum silicate glass, borosilicate glass, etc., can be used. Furthermore, aluminosilicate glass or lithium aluminum silicate glass is preferred as the protective glass 12, as these, even if thinner, allow for easy penetration of high stress through strengthening treatment, resulting in thin but high-strength glass. In addition, chemical strengthening treatment is usually carried out by immersing the glass in a molten salt containing an alkali metal.

[0056] The protective glass 12 preferably contains, based on oxide moles, 50-80% SiO2, 0.1-25% Al2O3, 3-30% Li2O+Na2O+K2O, 0-25% MgO, 0-25% CaO, and 0-5% ZrO2, but there are no particular limitations. Furthermore, 50-80% here means 50% to 80% when the total mole percentage of the protective glass 12 is set to 100%, and the same applies to other numerical ranges. Also, Li2O+Na2O+K2O refers to the combined content of Li2O, Na2O, and K2O. By setting the protective glass 12 to the following composition, its rigidity can be appropriately maintained even when the protective glass 12 is bent.

[0057] More specifically, the following glass composition is cited as a preferred composition for the glass used in protective glass 12. In addition, for example, "containing 0 to 25% MgO" means that MgO is not necessary but is contained at most 25%.

[0058] (i) The glass is a sodium-calcium silicate glass, (ii) and (iii) The glass is an aluminosilicate glass, and (iv) and (v) The glass is a lithium aluminosilicate glass.

[0059] (i) The glass, in mole percent, contains 63-73% SiO2, 0.1-5.2% Al2O3, 10-16% Na2O, 0-1.5% K2O, 0-5.0% Li2O, 5-18% MgO, and 1-10% CaO.

[0060] (ii) The glass, expressed in moles percent, contains 50–74% SiO₂, 5–15% Al₂O₃, 10–20% Na₂O, 0–8% K₂O, 0–5.0% Li₂O, 2–15% MgO, 0–6% CaO, and 0–5% ZrO₂, wherein the total content of SiO₂ and Al₂O₃ is 65–85%, the total content of Na₂O and K₂O is 12–25%, and the total content of MgO and CaO is 1–15%.

[0061] (iii) The glass, expressed in moles percent, contains 68–80% SiO₂, 4–10% Al₂O₃, 5–15% Na₂O, 0–1% K₂O, 0–5.0% Li₂O, 4–15% MgO, and 0–1% ZrO₂.

[0062] (iv) The glass, expressed in moles percent, contains 67-75% SiO₂, 0-4% Al₂O₃, 7-15% Na₂O, 1-9% K₂O, 0-5.0% Li₂O, 6-14% MgO, and 0-1.5% ZrO₂, with the combined content of SiO₂ and Al₂O₃ being 71-75%, and the combined content of Na₂O and K₂O being 12-20%. When CaO is present, its content is less than 1%.

[0063] (v) The glass, expressed in moles percent, contains 50–73% SiO₂, 5–20% Al₂O₃, 0–6% B₂O₃, 0–10% P₂O₅, 4–12% Li₂O, 3–20% Na₂O, 0–5% K₂O, 0–8% MgO, 0–2% CaO, 0–5% SrO, 0–5% BaO, 0–5% ZnO, 0–2% TiO₂, and 0–4% ZrO₂.

[0064] (Continuing with the area) Within the entire area of ​​the main surface 12B of the curved portion 20, the area overlapping with the bonding layer 16 is designated as the bonding region AR, and the area not overlapping with the bonding layer 16 is designated as region AR0. The bonding region AR is formed radially outside region AR0 when the axis passing through the center position of the curved portion 20 along the Z direction is taken as the axial direction.

[0065] In this embodiment, since the protective glass 12 is integrally formed as a curved portion 20, the area overlapping with the adhesive layer 16 within the entire main surface 12B of the protective glass 12 is the adhesive region AR. Furthermore, the adhesive region AR may be discontinuous, and multiple discontinuous or uneven adhesive regions AR may be formed.

[0066] Furthermore, within the entire area of ​​the main surface 12B of the bending portion 20, the area overlapping with the first bonding layer with an elastic modulus of 5 MPa or higher (the area overlapping with the first bonding layer within the bonding area AR) is designated as the first bonding area, and within the entire area of ​​the main surface 12B of the bending portion 20, the area overlapping with the second bonding layer with an elastic modulus of less than 5 MPa (the area overlapping with the second bonding layer within the bonding area AR) is designated as the second bonding area.

[0067] In this embodiment, since the protective glass 12 is integrally formed with a curved portion 20, the area that overlaps with the first bonding layer in the entire area of ​​the main surface 12B of the protective glass 12 is the first bonding area, and the area that overlaps with the second bonding layer in the entire area of ​​the main surface 12B of the protective glass 12 is the second bonding area. In this case, the area A1 of the first bonding region is preferably 8288 mm² or less, and the area A2 of the second bonding region is preferably 20214 mm² or less. Furthermore, the value obtained by adding the area A1 of the first bonding region and the area A2 of the second bonding region (referred to as region AR in this embodiment) and dividing it by the perimeter L ((A1+A2) / L) is preferably 80 mm or less. Additionally, there are cases where the area A1 of the first bonding region is referred to as the area of ​​the aforementioned first bonding layer in the aforementioned curved portion, and there are cases where the area A2 of the second bonding region is referred to as the area of ​​the aforementioned second bonding layer in the aforementioned curved portion.

[0068] This preferred numerical range can be applied to all of the following cases: setting the first connecting area without setting the second connecting area, setting the second connecting area without setting the first connecting area, and setting both the first and second connecting areas. Furthermore, when a first bonding area is provided but a second bonding area is not provided, the area A1 of the first bonding area is preferably 350 mm² to 95,000 mm², more preferably 740 mm² to 25,000 mm², and most preferably 1,500 mm² to 8,500 mm². Here, the area A1 of the first bonding area is preferably 350 mm² or more, more preferably 740 mm² or more, and most preferably 1,500 mm² or more; also, preferably 95,000 mm² or less, more preferably 25,000 mm² or less, and most preferably 8,500 mm² or less. Furthermore, in this case, the value (A1 / L) obtained by dividing the area A1 of the first adjacent region by the perimeter L is preferably 50 mm or less, more preferably 35 mm or less, and most preferably 25 mm or less.

[0069] Furthermore, when a second bonding area is provided but a first bonding area is not provided, the area A2 of the second bonding area is preferably 850 mm² to 230,000 mm², more preferably 1,700 mm² to 60,000 mm², and most preferably 3,800 mm² to 20,000 mm². Here, the area A2 of the second bonding area is preferably 850 mm² or more, more preferably 1,700 mm² or more, and most preferably 3,800 mm² or more; furthermore, it is preferably 230,000 mm² or less, more preferably 60,000 mm² or less, and most preferably 20,000 mm² or less. Furthermore, in this case, the value (A2 / L) obtained by dividing the area A2 of the second adjacent region by the perimeter L is preferably 115 mm or less, more preferably 85 mm or less, and most preferably 50 mm or less.

[0070] Furthermore, when both a first bonding region and a second bonding region are provided, the area A1 of the first bonding region is preferably 170 mm² to 47,000 mm², more preferably 370 mm² to 12,000 mm², and most preferably 790 mm² to 4,200 mm². Similarly, the area A2 of the second bonding region is preferably 420 mm² to 110,000 mm², more preferably 880 mm² to 29,000 mm², and most preferably 1,900 mm² to 10,000 mm². Here, the area A1 of the first bonding region is preferably 170 mm² or more, more preferably 370 mm² or more, and most preferably 790 mm² or more; it is also preferably 47,000 mm² or less, more preferably 12,000 mm² or less, and most preferably 4,200 mm² or less. Furthermore, the area A2 of the second subsequent region is preferably 420 mm2 or more, more preferably 880 mm2 or more, and most preferably 1900 mm2 or more. It is also preferably less than 110000 mm2, more preferably less than 29000 mm2, and most preferably less than 10000 mm2. Furthermore, in this case, the value obtained by adding the area A1 of the first adjacent region and the area A2 of the second adjacent region (area AR in this embodiment) and dividing it by the perimeter L ((A1+A2) / L) is preferably 80 mm or less, more preferably 60 mm or less, and most preferably 40 mm or less. By using the area of ​​the first and second bonding regions as the range, the size of the area AR0 displaying the image can be suppressed, and peeling from the frame can be suppressed. Furthermore, a printed layer is formed in the bonding region AR, and the region AR0 is used as, for example, a display unit.

[0071] (The relationship between the properties of protective glass) Here, when the protective glass is bent and attached to the frame, there is a risk that the protective glass may peel off from the frame due to its rebound, that is, due to the force intended to restore the protective glass to a flat shape. Through in-depth research, the inventors realized that by setting the relationship between the characteristics of the protective glass 12 (in this embodiment, the relationship between the radius of curvature R, thickness t, Young's modulus E, perimeter L, and the area of ​​the first or second attachment region) within an appropriate range, peeling from the frame can be suppressed. The relationship between the characteristics of the protective glass 12 will be explained below.

[0072] Subsequently, the correction value of the radius of curvature R of the curved portion 20 is set as the correction radius of curvature R'. The correction radius of curvature R' is expressed by the following formula (1). The correction radius of curvature R' is the correction value of the radius of curvature R when there is a flat region (flat portion) that is flat and not curved on both sides (one direction side and the other direction side) of the curved portion 20 in the X direction.

[0073] [Number 9]

[0074] In equation (1), the length F refers to the length in the X direction of the flat portion with the shorter length in the X direction among the flat portions that are adjacently connected on both sides of the curved portion 20 in the X direction. That is, the length F is the length of the flat portion with the shorter length in the X direction from one end in the X direction (the end connected to the curved portion 20) to the other end in the X direction (the end not connected to the curved portion 20) along the main surface. In this embodiment, since no flat portion is provided, F is zero, and the corrected radius of curvature R' is the same value as the radius of curvature R. An example with a flat portion will be described later.

[0075] (The case where the main surface 12A is a convex part) This section describes the case where the curved portion 20 is curved in such a way that it is a convex portion on the main surface 12A side. When the curved portion 20 is curved in such a way that it is a convex portion on the main surface 12A side, and C2 is set as shown in the following formula (5), when C2 is greater than 0 (C2>0), the curved portion 20 satisfies the following formula (6), and when C2 is less than or equal to 0 (C2≦0), the curved portion 20 satisfies the following formula (7). Furthermore, in formulas (5) to (7), when the second bonding region is not provided, A2 is zero, and when the first bonding region is not provided, A1 is zero.

[0076] [Number 10]

[0077] [Number 11]

[0078] [Number 12]

[0079] Equations (5) to (7) will be explained. Figure 5 is an example of a graph used to illustrate the relationship between the properties of the protective glass. The horizontal axis of Figure 5 is the corrected radius of curvature R', and the vertical axis is the value obtained by dividing the area (A1+A2) of the bonding region AR by the perimeter L, which will be appropriately referred to as the bonding width below.

[0080] The curves in Figure 5 represent the bonding width at the boundary of frame peeling for each modified radius of curvature R' when the thickness t and Young's modulus E are set to specific values. In other words, when the thickness t and Young's modulus E are specific values, if the bonding width is higher than the curve in Figure 5, frame peeling can be suppressed. As shown by the curves in Figure 5, the larger the modified radius of curvature R', the smaller the bonding width that can suppress peeling. When the modified radius of curvature R' is above a certain value R'0, the bonding width that can suppress peeling becomes constant.

[0081] As shown in the curve in Figure 5, when C2 is below 0, the bonding width that can suppress peeling is constant. That is, C2 in equation (5) is the index value for judging whether the bonding width that can suppress peeling is constant, and equation (7) can be said to be the formula for specifying the bonding width that can suppress peeling when the bonding width that can suppress peeling is constant. That is, when the curved part 20 is below C2, peeling can be suppressed by designing it to satisfy equation (7). In other words, peeling can be suppressed by setting the modified radius of curvature R', thickness t, perimeter L, area A1, and area A2 to be below C2, and setting the perimeter L, area A1, and area A2 to satisfy equation (7).

[0082] On the other hand, as shown in the curve in Figure 5, when C 2 is greater than 0, the peeling bonding width can be suppressed from changing accordingly with the modified radius of curvature R'. Equation (6) can be said to be a formula for the parameters such as the bonding width that can suppress the peeling when the peeling bonding width changes. That is, when C 2 is greater than 0, peeling can be suppressed by designing the curved part 20 to satisfy Equation (6). In other words, peeling can be suppressed by setting the modified radius of curvature R', thickness t, perimeter L, area A 1, and area A 2 to C 2 greater than 0, and setting the modified radius of curvature R', thickness t, Young's modulus E, perimeter L, area A 1, and area A 2 to satisfy Equation (6). In addition, Et 2 in Equation (6) is a parameter representing the rigidity of the protective glass 12, and E(t / R') is a parameter representing the bending stress.

[0083] (The case where the main surface 12B is a convex part) This section describes the case where the curved portion 20 is curved in such a way that it is a convex portion on the main surface 12B side. When the curved portion 20 is curved in such a way that it is a convex portion on the main surface 12B side, and C1 is set as shown in the following formula (2), when C1 is greater than 0 (C1>0), the curved portion 20 satisfies the following formula (3), and when C1 is less than or equal to 0 (C1≦0), the curved portion 20 satisfies the following formula (4). Furthermore, in formulas (2) to (4), when the second bonding region is not provided, A2 is zero, and when the first bonding region is not provided, A1 is zero.

[0084] [Number 13]

[0085] [Number 14]

[0086] [Number 15]

[0087] As shown in the curve in Figure 5, when C1 is below 0, the bonding width that can suppress peeling is constant. In Equation (2), C1 is the index value for determining whether the bonding width that can suppress peeling is constant, and Equation (4) can be said to be the formula for specifying the bonding width that can suppress peeling when the bonding width that can suppress peeling is constant. That is, when the curved part 20 is below C1, peeling can be suppressed by designing it to satisfy Equation (4). In other words, peeling can be suppressed by setting the modified radius of curvature R', thickness t, perimeter L, area A1, and area A2 to be below C1, and setting the perimeter L, area A1, and area A2 to satisfy Equation (4).

[0088] On the other hand, as shown in the curve in Figure 5, when C1 is greater than 0, the peeling bonding width can be suppressed from changing accordingly with the modified radius of curvature R'. Equation (3) can be said to be a formula for specifying the parameters such as the peeling bonding width that can be suppressed when the peeling bonding width changes. That is, when C1 is greater than 0, peeling can be suppressed by designing the bent part 20 to satisfy equation (3). In other words, peeling can be suppressed by setting the modified radius of curvature R', thickness t, perimeter L, area A1, and area A2 to be greater than 0, and setting the modified radius of curvature R', thickness t, Young's modulus E, perimeter L, area A1, and area A2 to satisfy equation (3).

[0089] When C1 is greater than 0 (C1>0), it is preferable that the curved portion 20 further satisfies the following equation (6). Furthermore, in equation (6), A2 is zero when the second bonding region is not provided, and A1 is zero when the first bonding region is not provided. When the curved portion 20 satisfies equation (6), since the protective glass 12 is firmly attached by the frame 14, it is easy to suppress peeling even under long-term exposure to high temperature, thermal cycling, mechanical vibration, impact, ultraviolet rays, etc. Furthermore, by satisfying equation (6) through the bending portion 20, as shown in Figure 13, in addition to the bending portion that is a protrusion on the side of the main surface 12B, it also has a bending portion that is a protrusion on the side of the main surface 12A. Even if the connection width with the frame is set to be the same in both bending portions, peeling can be suppressed, thus having the advantage of excellent design.

[0090] [Number 16]

[0091] As explained above, the glass article 10 of this embodiment includes: a protective glass 12 having a main surface 12A (first main surface) and a main surface 12B (second main surface); and a frame 14 attached to the main surface 12B side of the protective glass 12 via an adhesive layer 16. A curved portion 20 convex towards the main surface 12A is provided on the protective glass 12. The adhesive layer 16 includes at least one of a first adhesive layer with an elastic modulus of 5 MPa in an indentation elastic modulus test and a second adhesive layer with an elastic modulus of less than 5 MPa in an indentation elastic modulus test. When R' is set as shown in equation (1) and C2 is set as shown in equation (5), the curved portion 20 satisfies equation (6) when C2>0 and equation (7) when C2≦0. The glass article 10 of this embodiment can suppress peeling from the frame 14 by the curved portion 20 satisfying equation (6) or equation (7).

[0092] As described above, the glass article 10 of this embodiment includes: a protective glass 12 having a main surface 12A (first main surface) and a main surface 12B (second main surface); and a frame 14 attached to the main surface 12B side of the protective glass 12 via an adhesive layer 16. A curved portion 20 convex towards the main surface 12B is provided on the protective glass 12. The adhesive layer 16 includes at least one of a first adhesive layer having an elastic modulus of 5 MPa or more in an indentation elastic modulus test, and a second adhesive layer having an elastic modulus of less than 5 MPa in an indentation elastic modulus test. When R' is set as shown in equation (1) and C1 is set as shown in equation (2), the curved portion 20 satisfies equation (3) when C1>0 and equation (4) when C1≦0. The glass article 10 of this embodiment can suppress peeling from the frame 14 by the curved portion 20 satisfying equation (3) or equation (4). Furthermore, the curved portion 20 preferably satisfies equation (6) when C 1>0.

[0093] The (A1+A2) / L is preferably 80 mm or less. By using this range, the narrowing of the AR0 area is suppressed, improving design flexibility and preventing the displayed image from becoming too small. Furthermore, by using this range, the bonding area is reduced, facilitating adhesion and improving positional accuracy. More preferably, the (A1+A2) / L is 60 mm or less. By using this range, bonding defects are reduced, bonding is performed with high reliability, air venting is promoted, and the adhesive is appropriately distributed throughout the bonding area.

[0094] The adhesive layer 16 may include both a first adhesive layer and a second adhesive layer, which may be composed of different adhesives. By including both the first and second adhesive layers, the protective glass 12 and the frame 14 can be properly bonded. For example, by providing adhesive layers with different characteristics, such as a second adhesive layer with low adhesion (like double-sided tape) but which immediately exhibits adhesion after application, and a first adhesive layer with high final adhesion strength (like a moisture-curing adhesive) but which takes time to exhibit strength, the protective glass 12 and the frame 14 can be bonded with high positional accuracy and sufficient adhesion.

[0095] Figure 6 shows an example of a configuration where both a first adhesive layer and a second adhesive layer are provided. In the case of both a first adhesive layer and a second adhesive layer, it is preferable to position the second adhesive layer AR2 further radially outward than the first adhesive layer AR1. By providing a second adhesive region with lower adhesion on the outer side, and by having the second adhesive region (e.g., double-sided tape) function as a barrier for the adhesive in the first adhesive region, the adhesion of the first adhesive region before curing can be prevented from being exposed on the outer side.

[0096] In the example of Figure 6, with the outer periphery of the first adhesive layer AR1 separated from the inner periphery of the second adhesive layer AR2, the second adhesive layer AR2 is positioned radially outward than the first adhesive layer AR1. However, Figure 6 is an example, and the positions of the first and second adhesive layers can be arbitrarily set when both the first and second adhesive layers are provided.

[0097] The thickness t of the protective glass 12 is preferably between 0.3 mm and 3.0 mm. By setting the thickness t within this range, peeling from the frame 14 can be better suppressed.

[0098] The radius of curvature R of the curved portion 20 is preferably between 50 mm and 10,000 mm. By setting the radius of curvature R within this range, design flexibility can be improved, and peeling from the frame 14 can be better suppressed.

[0099] The Young's modulus E of the protective glass 12 is preferably between 60 GPa and 90 GPa. By setting the Young's modulus E within this range, peeling from the frame 14 can be better suppressed.

[0100] The vehicle-mounted display device 2 of this embodiment includes a display 3 and a glass item 10 disposed on the surface (front) of the display 3. The vehicle-mounted display device 2 can prevent the frame 14 from peeling off from the protective glass 12.

[0101] (Other examples) The following describes other examples of the shape of the protective glass 12.

[0102] (Example of spline shape) Figure 7 is a schematic diagram of a protective glass according to another example of this embodiment. In the above embodiment, the curved portion 20 is described as a portion that bends with the same radius of curvature R, but sometimes it also bends in the X direction in the form of a spline curve with an indeterminate radius of curvature. In this case, the entire portion that bends in the X direction in the form of a spline curve is treated as the curved portion 20.

[0103] In the above description of the embodiment, the area on the main surface 12B that is bent with the Y direction as the bending axis, where the change in the radius of curvature R measured at each position from one end point to the other end point in the X direction is less than 5%, is treated as a single bent portion 20 with the same radius of curvature. On the other hand, in this example, the region on the main surface 12B where the curvature radius R varies more than 5% within a length of less than 50 mm from one end point in the X direction to the other end point in the region that is bent with the Y direction as the bending axis is treated as a bending portion 20 of the spline shape. Moreover, as shown in FIG7, the bending portion 20 of the spline shape is approximated as a shape bent with a certain curvature radius, and the curvature radius when approximating a shape bent with a certain curvature radius is treated as the curvature radius R of the bending portion 20. Specifically, one endpoint of the main surface 12B of the spline-shaped curved portion 20 in the X direction is designated as endpoint 20J, and the other endpoint is designated as endpoint 20K. The plane connecting endpoints 20J and 20K along the X and Y directions (i.e., the XY plane passing through endpoints 20J and 20K) is designated as plane α. Furthermore, when plane α is moved parallel to the main surface 12B in the Z direction and designated as plane β, the radius of curvature of the arc 20R passing through endpoints 20J and 20K and connecting with plane β is designated as the radius of curvature R of the curved portion 20.

[0104] (Example with a flat section) Figures 8 and 9 are schematic diagrams of another example of the protective glass in this embodiment. A flat portion 22 can be connected to the curved portion 20 in the X direction. The flat portion 22 is connected to the curved portion 20 in a manner where the main surface 12B is continuous with respect to the curved portion 20 (in a manner that is not discontinuous). Figure 8 shows an example where the flat portion 22 is connected to one side (one side) of the curved portion 20 in the X direction. The flat portion 22 is a flat portion connected to the end of the curved portion 20 in the X direction throughout the entire area of ​​the protective glass 12. The flat portion 22 is flat and is not limited to having an infinite radius of curvature; it also includes portions with a radius of curvature greater than 10,000 mm.

[0105] When the curved portion 20 is connected to the flat portion 22, for the application of equations (1) to (7), the curved portion 20 and the flat portion 22 are treated as a single curved portion 20a. For example, when the flat portion 22 is provided on one side of the curved portion 20 in the X direction as shown in FIG8, and the flat portion 22 is not provided on the other side in the X direction, the length of the curved portion 20a in the X direction (the sum of the length of the curved portion 20 in the X direction and the length F of the flat portion 22) is treated as the perimeter L.

[0106] Furthermore, the area of ​​the region overlapping with the first bonding layer on the main surface 12B of the curved portion 20a (the sum of the areas of the regions overlapping with the first bonding layer on the main surface 12B of the curved portion 20 and the areas of the regions overlapping with the first bonding layer on the main surface 12B of the flat portion 22) is treated as area A1. Also, the area of ​​the region overlapping with the second bonding layer on the main surface 12B of the curved portion 20a (the sum of the areas of the regions overlapping with the second bonding layer on the main surface 12B of the curved portion 20 and the areas of the regions overlapping with the second bonding layer on the main surface 12B of the flat portion 22) is treated as area A2. However, if a flat portion 22 is provided on one side of the curved portion 20 in the X direction, and no flat portion 22 is provided on the other side in the X direction, the length F in equation (1) is treated as zero in the same way as in the case without the flat portion 22. In other words, if the curved portion 20 is provided only on one side, the radius of curvature R' is corrected to the same value as the radius of curvature R.

[0107] As shown in Figure 9, the flat portion 22 can be configured to connect to both sides of the curved portion 20 in the X direction (one side and the other side in the X direction).

[0108] As shown in Figure 9, when the lengths of the flat portion 22 on one side of the curved portion 20 along the main surface 12B are different from those on the other side, the curved portion 20 and the flat portion 22 with the shorter length along the main surface 12 are treated as a single curved portion 20a. That is, the length of the shorter flat portion 22 along the main surface 12B is treated as the length F in equation (1), and the length of the curved portion 20a in the X direction (the sum of the length of the curved portion 20 and the length F of the shorter flat portion 22) is treated as the perimeter L. Furthermore, the area of ​​the region overlapping with the first bonding layer in the main surface 12B of the curved portion 20a (the sum of the area of ​​the region overlapping with the first bonding layer in the main surface 12B of the curved portion 20 and the area of ​​the region overlapping with the first bonding layer in the main surface 12B of the shorter flat portion 22) is treated as area A1. Furthermore, the area of ​​the region overlapping with the second bonding layer on the main surface 12B of the curved portion 20a (the sum of the area of ​​the region overlapping with the second bonding layer on the main surface 12B of the curved portion 20 and the area of ​​the region overlapping with the second bonding layer on the main surface 12B of the shorter flat portion 22) is treated as area A2. In addition, when the flat portion 22 on one side of the curved portion 20 and the flat portion 22 on the other side have the same length along the main surface 12B, the curved portion 20 and any one of the flat portions 22 are treated as one curved portion 20a.

[0109] (Example of a case where there are multiple bends) Figures 10 and 11 are schematic diagrams of a protective glass according to another embodiment. A plurality of curved portions 20 can be provided; in other words, a plurality of curved portions 20 with different radii of curvature R can be formed on the protective glass 12. In this case, each curved portion 20 bends in the same direction, i.e., the Y-direction, as the bending axis.

[0110] The number of bends 20 can be determined as follows: Specifically, it is determined that within a region of the main surface 12B that bends along the Y-axis, the change in radius of curvature R at various positions within a length of less than 50 mm from one end point in the X-axis to the other end point is greater than 5%, thus forming a plurality of bends 20 with different radii of curvature R. In other words, when the change in radius of curvature R is less than 5% within a length of less than 50 mm from one end point in the X-axis to the other end point of the region of the main surface 12B that bends along the Y-axis, but the change in radius of curvature R exceeds 5% within a length of more than 50 mm from one end point to the other end point, it is determined that a plurality of bends are formed, rather than a single bend in a spline shape.

[0111] In this case, as shown in the example of Figure 10, a single curved section 20A with the same radius of curvature R is defined as the region on the main surface 12B that is curved with the Y direction as the bending axis, where the change in radius of curvature R at each position from one endpoint 20L in the X direction of this region to the other endpoint 20M. The curved section 20A is the region from one endpoint 20L to the position 20N where the change in radius of curvature R is greater than 5%. Furthermore, another curved section 20B is defined as the region where the change in radius of curvature R at each position from position 20N to the other endpoint 20M is less than 5%.

[0112] In the example of Figure 10, since the change in radius of curvature from position 20N to endpoint 20M is less than 5%, the region from position 20N to endpoint 20M is treated as a curved section 20. However, for example, if there is a position from position 20N to endpoint 20M where the change in radius of curvature R is greater than 5%, then the region from position 20N to the position where the change in radius of curvature R is greater than 5% is one curved section 20B. In this case, there are three or more curved sections 20.

[0113] In the case where a plurality of curved portions 20 are formed as described above, equations (1) to (7) are applied to each curved portion 20. That is, when each curved portion 20 is a convex portion on the main surface 12A side, it satisfies equation (6) or equation (7), and when it is a convex portion on the main surface 12B side, it satisfies equation (3) or equation (4). Figure 10 shows an example formed by a curved portion 20A with a radius of curvature R1 and a curved portion 20B with a radius of curvature R2. In the example of Figure 10, both curved portions 20A and 20B are convex portions on the main surface 12A side, but it is not limited to this. It is possible for both curved portions 20A and 20B to be convex portions on the main surface 12B side. Furthermore, the number of curved portions 20 is not limited to two, but can be three or more.

[0114] Figure 11 shows an example of a case where a plurality of curved portions 20 are connected to flat portions 22. In the case where a plurality of curved portions 20 are connected to flat portions 22, in accordance with the application of equation (7) of equation (1), one curved portion 20 and the flat portion 22 connected to the curved portion 20 are treated as one curved portion 20a.

[0115] In the example of Figure 11, a longer flat portion 22 is connected to one side of the curved portion 20A in the X direction, and a shorter flat portion 22 is connected to the other side of the curved portion 20A in the X direction. A curved portion 20B is connected to the shorter flat portion 22 on the opposite side of the curved portion 20A. In this case, the curved portion 20A and the shorter flat portion 22 are treated as one curved portion 20a, and the curved portion 20B and the shorter flat portion 22 are treated as another curved portion 20a. The calculation methods for the length F, perimeter L, area A1, and area A2 of the curved portion 20a are the same as those for the case where a flat portion 22 is connected to a curved portion 20, so the explanation is omitted. Furthermore, in the example of Figure 11, since the flat portion 22 is only connected to one side of the curved portion 20A, the length F in equation (1) of the curved portion 20A is treated as zero.

[0116] Figures 12 and 13 are schematic diagrams of a protective glass according to another embodiment of this invention. In the above description, the plurality of curved portions 20 are convex portions on the same side, but may be convex portions in different directions. For example, as shown in Figure 12, curved portion 20A may be a convex portion on the main surface 12A side, and curved portion 20B may be a convex portion on the main surface 12B side.

[0117] Furthermore, in the example of Figure 13, a longer flat portion 22 is connected to one side of the curved portion 20A in the X direction, and a shorter flat portion 22 is connected to the other side of the curved portion 20A in the X direction. A curved portion 20B is connected to the shorter flat portion 22 on the opposite side of the curved portion 20A. In this case, the curved portion 20A and the shorter flat portion 22 are treated as one curved portion 20a, and the curved portion 20B and the shorter flat portion 22 are treated as another curved portion 20. The calculation methods for the length F, perimeter L, area A1, and area A2 of the curved portion 20a are the same as those for the case where a flat portion 22 is connected to a curved portion 20, so the explanation is omitted. Furthermore, equations (1) to (7) are applied to each curved portion. That is, since the curved part 20A is a convex part on the main surface 12A side, it satisfies equation (6) or equation (7), and since the curved part 20B is a convex part on the main surface 12B side, it satisfies equation (3) or equation (4).

[0118] Figures 14 to 17 are schematic diagrams of another example of protective glass in this embodiment. In the above description of the embodiment, since a rectangular glass plate is bent in the X direction to form the protective glass 12, the length of the protective glass 12 in the X direction is constant at each position. However, the length of the protective glass 12 in the X direction sometimes varies at each position depending on the shape. The perimeter L in such cases will be explained below.

[0119] As described above, the perimeter L refers to the length of the line on the main surface 12B pointing towards the X direction, connecting the position of the curved portion 20 on the side closest to the X direction of the bending axis YA along the Y direction to the position of the curved portion 20 on the other side closest to the bending axis YA. Therefore, as shown in Figure 14, when a trapezoidal glass plate is bent with the Y direction as the bending axis to serve as protective glass 12, the two ends of the long side of the trapezoid, i.e., the side surface 12C3, are the positions 20C and 20D of the curved portion 20 on the side closest to the X direction of the bending axis YA, and the length of the line connecting positions 20C and 20D on the main surface 12B pointing towards the X direction is the perimeter L.

[0120] Furthermore, in the above explanation, the X direction orthogonal to the bending axis is along the lateral side of the flat protective glass 12 before bending, namely the sides 12C3 and 12C4. However, it is not limited to this; the X direction orthogonal to the bending axis may be offset (or intersect) with respect to the sides of the flat protective glass 12 before bending. Figure 15 shows an example where the X direction intersects with respect to the sides 12C3 and 12C4 of the flat protective glass 12 before bending. In the example of Figure 15, one endpoint of the long side of the trapezoid, namely side 12C3, is position 20C, and the other endpoint of the short side of the trapezoid, namely side 12C4, is position 20D. Furthermore, in the example of Figure 15, since the positions of positions 20C and 20D in the Y direction are not aligned, the length of the line connecting position 20D' (after offsetting position 20D in the Y direction) and position 20C, and extending along the surface of the main surface 12B towards the X direction, is set as the perimeter L. That is, in the example of Figure 15, the length of the curve connecting position 20C and position 20D' with a radius of curvature R is the perimeter L. Furthermore, position 20D' is the position after offsetting position 20D in the Y direction, with its Y-direction position aligned with the Y-direction position of position 20C. Thus, in the case where the Y-direction positions of positions 20C and 20D are not aligned, the length of the line extending in the X direction along the surface of the main surface 12B from position 20C (where the Y-direction positions are aligned) to position 20D' is defined as the perimeter.

[0121] Figure 16 shows an example of a polygonal glass plate bent along a line segment YA in the direction Y as a bending axis to serve as protective glass 12. Similarly, in the example of Figure 16, since the points on the X-direction side of the bent portion 20 relative to the bending axis YA in the direction Y, namely positions 20C and 20D, are not aligned in the Y-direction, the length of the line connecting positions 20D' and 20C along the surface of the main surface 12B towards the X-direction is the circumference L.

[0122] Figure 17 shows an example of a protective glass 12 where a curved glass plate is bent along a line segment YA in the direction Y as the bending axis. Similarly, in the example of Figure 17, since the points on the X-direction side of the curved portion 20 closest to the bending axis YA along the direction Y, namely positions 20C and 20D, are not aligned in the Y-direction, the length of the line connecting positions 20D' and 20C along the surface of the main surface 12B towards the X-direction is the circumference L.

[0123] Figures 18 to 20 are schematic diagrams of a protective glass according to another embodiment. In the above description, a plurality of curved portions 20 bend in the same direction with the Y-direction as the bending axis, but the directions of the bending axes of the plurality of curved portions 20 may be different. In this case, the bending axes of each curved portion 20 do not intersect on the main surface 12A of the protective glass 12, and intersect at a point extended further outward than the main surface 12A. Even when the directions of the bending axes of the curved portions 20 are different, by ensuring that the bending axes do not intersect each other on the main surface 12A, the planar unfolding of the protective glass 12 can be achieved, allowing for appropriate cold forming.

[0124] Figures 18 and 19 show schematic examples of protective glass 12 with multiple curved sections 20 having different bending axis directions. In the example of Figure 18, a curved section 20A is connected to one side of the flat section 22 in the X direction, and a curved section 20B is connected to the other side of the flat section 22 in the X direction.

[0125] The bending portion 20A is bent from one end edge (side surface 12C1) in the X direction to the other end edge 20P, with the bending axis YA as the bending axis. That is, the bending portion 20A is a region bent with the bending axis YA as the bending axis, such that the change in the radius of curvature at each position in the X direction from the side surface 12C1 to the end edge 20P is less than 5%. The curved portion 20B is bent from one end edge 20Q in the X direction to the other end edge, i.e., the side surface 12C2, with the bending axis YB as the bending axis. That is, the curved portion 20B is a region bent with the bending axis YB as the bending axis, such that the change in the radius of curvature at each position in the X direction from the end edge 20Q to the side surface 12C2 is less than 5%. The flat portion 22 is a flat region in the X direction from the end edge 20P to the end edge 20Q.

[0126] The bending axis YA of the curved portion 20A and the bending axis YB of the curved portion 20B extend in different directions, but do not intersect on the main surface 12A of the protective glass 12. The bending axes YA and YB intersect at a point further outward than the main surface 12A. Furthermore, for ease of explanation, Figure 18 is shown with the Y direction as the bending axis, that is, the bending axes YA and YB are in the same direction. However, in reality, the bending axes YA and YB of the curved portions 20A and 20B extend in different directions.

[0127] In the case where a plurality of curved portions 20 with different directions of bending axis are connected to flat portions 22, for the application of formula (7) of formula (1), one curved portion 20 and the flat portion 22 connected to the curved portion 20 are treated as one curved portion 20a.

[0128] In the example of Figure 19, a flat portion 22 is connected to the other side of the curved portion 20A in the X direction, and a flat portion 22 is connected to one side of the curved portion 20B in the X direction. In this case, the curved portion 20A and the flat portion 22 are treated as one curved portion 20a, and the curved portion 20B and the flat portion 22 are treated as another curved portion 20. The calculation methods for the length F, area A1, and area A2 of the curved portion 20a are the same as those for the case where a flat portion 22 is connected to one curved portion 20, so the explanation is omitted. Furthermore, in the example of Figure 19, since the flat portion 22 is connected to only one side of the curved portions 20A and 20B, the length F in equation (1) for the curved portions 20A and 20B is treated as zero.

[0129] Based on Figure 20, the method for calculating the perimeter L of a plurality of curved portions 20 with different directions of the bending axis is explained. For ease of explanation, Figure 20 uses a diagram showing a curved portion 20a including the curved portion 20A and the flat portion 22. In the example of Figure 20, the endpoint of the side 12C1 closest to the X direction is the position 20C of the curved portion 20a, and the endpoint of the other side of the end edge 20P' closest to the X direction is the position 20D of the curved portion 20a.

[0130] In the example of Figure 20, since the positions 20C and 20D are not aligned in the Y direction, the length of the line connecting position 20D' (after offsetting position 20D in the Y direction) and position 20C, and extending along the surface of the main surface 12B towards the X direction, is defined as the perimeter L of the curved portion 20a. That is, in the example of Figure 20, the length of the curve connecting position 20C and position 20D' with a radius of curvature R is the perimeter L. Furthermore, the perimeter L is also calculated similarly for the curved portion 20a, which includes the curved portion 20B and the flat portion 22, but the explanation is omitted. Example

[0131] Next, the embodiments will be described. Furthermore, the embodiments can be modified as long as the effects of the invention are achieved. In each example, either actual experiments or simulations were conducted. In Tables 1-10 described later, those marked "Yes" indicate actual experiments, while blank columns indicate simulations. Also, in Figures 21-42 described later, the results of actual experiments are enclosed in circles.

[0132] (simulation) For the simulation, impact and collision analysis software (PAM-CRASH, manufactured by ESI Corporation, Japan) using the finite element method was employed. In the simulation, COS3D (Material Type 305), with adjustable bonding breakage energy, was used as the bonding layer, and the bonding breakage energy EFRSn was set in a manner integrated with actual experiments. In the simulation, firstly, the glass plate was subjected to bending elastic energy (accumulated as stress in the glass). Secondly, the frame is attached to the curved glass plate via an adhesive layer. Because both the adhesive layer and the frame deform due to the elastic energy of the glass, the adhesive energy in the adhesive layer exceeds the bonding breakage energy, thus simulating the phenomenon of glass peeling off from the frame. Furthermore, it has been confirmed that there is no discrepancy between the simulation results and the actual experimental results. Also, the bonding breakage energy of the weak adhesive layer in the simulation is set based on the actual experimental results of the weak adhesive layer.

[0133] (Simulation conditions) Under the conditions described below and in the examples, models corresponding to the actual tests were constructed, and it was determined whether delamination occurred. The case where no delamination occurred was designated as A (adhesive), and the case where delamination occurred within 2 msec was designated as B (non-adhesive). • Young's modulus of the glass plate: 70 GPa (G=29.17, K=38.89), 74 GPa (G=30.08, K=45.68), 77 GPa (G=31.56, K=45.83) • Young's modulus of the frame: 206 GPa (G=79.231, K=171.667) Here, G refers to the shear elastic modulus, and K refers to the bulk elastic modulus.

[0134] (Actual experiment) In the actual experiment, an AGC aluminosilicate glass plate (product name Dragontrail) was used as the glass plate. This glass plate was bent laterally (X-direction) with either a convex portion on the side not attached to the frame (first main surface) or a convex portion on the side attached to the frame (second main surface) to serve as protective glass for bending in the X-direction. The peripheral ends were attached to the frame via an adhesive layer without protruding from the frame. The frame was made of rolled SS400 steel, using either Tri-Bond 1539 as the strong adhesive layer (first adhesive layer) or 3M VHX-1701-04 as the weak adhesive layer (second adhesive layer). In the actual test, the protective glass was evaluated for whether it peeled off from the frame during a visual inspection after 200 hours. Cases that did not peel off after 200 hours were designated as A (adhesive), and cases that peeled off after 200 hours were designated as B (non-adhesive).

[0135] [Table 1] Table 1 CG thickness t (mm) CG Young's Modulus (GPa) Radius of curvature (mm) Next, calculate the area A1 (mm²). Next, calculate the area A2 (mm2). Perimeter L (mm) Next, calculate the area / perimeter (mm). Can it fit? Satisfaction type 6 Actual test radius of curvature R Corrected curvature R' Bending section Short lateral flattened part Bending section Short lateral flattened part Bending section Long lateral flat part Short lateral flattened part F Example 1 1.1 74 400 400 4420 0 0 0 250 0 0 18 B 1.1 74 400 400 3481 0 0 0 250 0 0 14 B 1.1 74 400 400 2370 0 0 0 250 0 0 9 B 1.1 74 600 600 1538 0 0 0 250 0 0 6 B 1.1 74 600 600 1538 0 0 0 250 0 0 6 B 1.1 74 800 800 939 0 0 0 250 0 0 4 B 1.1 74 800 800 316 0 0 0 250 0 0 1 B 1.1 74 600 600 1538 0 0 0 250 100 0 6 B 1.1 74 600 600 1538 0 0 0 250 150 0 6 B Example 2 1.1 74 400 400 6355 0 0 0 250 0 0 twenty five A 1.1 74 600 600 4481 0 0 0 250 0 0 18 A 1.1 74 600 600 3067 0 0 0 250 0 0 12 A 1.1 74 1200 1200 1620 0 0 0 250 0 0 6 A have 1.1 74 1000 1000 1620 0 0 0 250 0 0 6 A have 1.1 74 800 800 1550 0 0 0 250 0 0 6 A

[0136] (Example 1, Example 2) Table 1 shows the characteristics of the protective glass in Examples 1 and 2. Figure 21 is a graph showing the evaluation results of each protective glass in Examples 1 and 2. In Examples 1 and 2, a rectangular glass plate with a thickness t of 1.1 mm, a longitudinal (Y-direction) length of 150 mm, and a transverse (X-direction) length of 250 mm was prepared. The Young's modulus of the glass plate was 74 GPa. It is envisioned that AGC manufactures aluminosilicate (product name Dragontrail) glass plates. In Examples 1 and 2, because the protective glass is bent laterally (in the X direction) with a protrusion on the side that connects to the frame (the second main surface side), and the entire protective glass is bent, a flat portion is not formed, and the whole is a single bent portion. As the adhesive layer, an adhesive equivalent to the first adhesive layer (tri-bonded adhesive 1539) is envisioned. The frame is envisioned to be made of rolled steel SS400. In Examples 1 and 2, multiple samples with different radii of curvature R, areas A1, and perimeters L were prepared as shown in Table 1.

[0137] Figure 21 is a graph showing the relationship between the radius of curvature R of each sample in Examples 1 and 2 and the value obtained by dividing the area of ​​the bonding region (here, the area of ​​the first bonding region A1) by the perimeter L (bonding width). The solid line in Figure 21 is the boundary line indicating whether equation (3) or equation (4) is satisfied. The sample with the value above the solid line on the vertical axis can be said to satisfy equation (3) or equation (4). The dashed lines in Figure 21 are the boundary lines that satisfy equation (6), and the vertical axis values ​​are the samples above the dashed lines that satisfy equation (6).

[0138] Example 1, as a comparative example, does not satisfy equation (3) or equation (4), so it can be seen that the protective glass peels off from the frame. Example 2, as an embodiment, satisfies equation (3) or equation (4), so it can be seen that the peeling of the protective glass from the frame can be suppressed.

[0139] [Table 2] Table 2 CG thickness t (mm) CG Young's Modulus (GPa) Radius of curvature (mm) Next, calculate the area A1 (mm²). Next, calculate the area A² (mm²). Perimeter L (mm) Next, calculate the area / perimeter (mm). Can it fit? Satisfaction type 6 Actual test radius of curvature R Corrected curvature R' Bending section Short lateral flattened part Bending section Short lateral flattened part Bending section Long lateral flat part Short lateral flattened part F Example 3 1.1 74 400 655 1246 347 0 0 250 50 50 5 B 1.1 74 600 702 953 48 0 0 250 20 20 4 B 1.1 74 600 855 953 121 0 0 250 50 50 4 B 1.1 74 600 855 953 121 0 0 250 100 50 4 B 1.1 74 400 655 581 296 0 0 250 50 50 3 B 1.1 74 600 1110 370 56 0 0 250 100 100 1 B Example 4 1.1 74 400 655 6166 560 0 0 250 50 50 twenty two A 1.1 74 400 910 6166 1341 0 0 250 100 100 twenty one A satisfy 1.1 74 400 1165 6166 2122 0 0 250 150 150 twenty one A satisfy 1.1 74 400 655 2909 555 0 0 250 50 50 12 A 1.1 74 400 910 2909 1016 0 0 250 100 100 11 A 1.1 74 400 1165 2909 1393 0 0 250 150 150 11 A fullness 1.1 74 400 655 2370 346 0 0 250 50 50 9 A 1.1 74 600 855 2146 298 0 0 250 50 50 8 A 1.1 74 600 1110 1538 420 0 0 250 100 100 6 A 1.1 74 600 1110 953 241 0 0 250 100 100 3 A 1.1 74 600 1365 953 362 0 0 250 150 150 3 A

[0140] (Example 3, Example 4) Table 2 shows the characteristics of the protective glass in Examples 3 and 4. Figure 22 is a graph showing the evaluation results of each protective glass in Examples 3 and 4. In Examples 3 and 4, a portion of the protective glass was bent, and flat portions were formed on both sides of the bent portion. In Examples 3 and 4, multiple samples with different radii of curvature R, areas A1, and perimeters L were prepared as shown in Table 1. For other aspects, the same procedures applied as in Examples 1 and 2. As shown in Table 2 and Figure 22, Example 3, as a comparative example, does not satisfy equation (3) or equation (4), indicating that the protective glass peels off from the frame. Example 4, as an embodiment, satisfies equation (3) or equation (4), indicating that the peeling of the protective glass from the frame can be suppressed. Furthermore, some samples in Example 4 further satisfy equation (6).

[0141] [Table 3] Table 3 CG thickness t (mm) CG Young's Modulus (GPa) Radius of curvature (mm) Next, calculate the area A1 (mm²). Next, calculate the area A² (mm²). Perimeter L (mm) Next, calculate the area / perimeter (mm). Can it fit? Satisfaction type 6 Actual test radius of curvature R Corrected curvature R' Bending section Short lateral flattened part Bending section Short lateral flattened part Bending section Long lateral flat part Short lateral flattened part F Example 5 0.7 74 200 200 1365 0 0 0 250 0 0 5 B 0.7 74 200 200 1428 0 0 0 250 0 0 6 B 0.7 74 200 200 2669 0 0 0 250 0 0 11 B Example 6 0.7 74 400 400 1599 0 0 0 250 0 0 6 A 0.7 74 400 400 3116 0 0 0 250 0 0 12 A satisfy 0.7 74 200 200 4301 0 0 0 250 0 0 17 A 0.7 74 200 200 5334 0 0 0 250 0 0 twenty one A Example 7 0.7 74 200 262 1428 65 0 0 250 20 20 6 B Example 8 0.7 74 200 290 1428 95 0 0 250 29 29 5 A 0.7 74 200 340 1806 127 0 0 250 45 45 7 A Example 9 0.5 74 200 200 291.1 0 0 0 250 0 0 1 B Example 10 0.5 74 200 200 1365.3 0 0 0 250 0 0 5 A 0.5 74 200 200 2669.1 0 0 0 250 0 0 11 A

[0142] (Example 5, Example 6) Table 3 shows the characteristics of the protective glass in Examples 5 to 10. Figure 23 is a graph showing the evaluation results of each protective glass in Examples 5 and 6. In Examples 5 and 6, the thickness of the protective glass is set to 0.7 mm, and the radius of curvature R, area A1, and perimeter L are set as shown in Table 3, which are the same as in Examples 1 and 2. As shown in Table 3 and Figure 23, Example 5, as a comparative example, does not satisfy equation (3) or equation (4), indicating that the protective glass peels off from the frame. Example 6, as an embodiment, satisfies equation (3) or equation (4), indicating that the peeling of the protective glass from the frame can be suppressed. Furthermore, some samples in Example 6 further satisfy equation (6).

[0143] (Example 7, Example 8) Figure 24 is a graph showing the evaluation results of the protective glass in Examples 7 and 8. In Examples 7 and 8, except that a portion of the protective glass is bent and flat portions are formed on both sides of the bent portion, and the radius of curvature R, area A1, and perimeter L are set as shown in Table 3, the results are the same as in Examples 5 and 6. As shown in Table 3 and Figure 24, Example 7, as a comparative example, does not satisfy Equation (3) or Equation (4), indicating that the protective glass peels off from the frame. Example 8, as an embodiment, satisfies Equation (3) or Equation (4), indicating that the peeling of the protective glass from the frame can be suppressed.

[0144] (Example 9, Example 10) Figure 25 is a graph showing the evaluation results of the protective glass in Examples 9 and 10. In Examples 9 and 10, the thickness of the protective glass is set to 0.5 mm, and the radius of curvature R, area A1, and perimeter L are set as shown in Table 3, which are the same as in Examples 1 and 2. As shown in Table 3 and Figure 25, Example 9, as a comparative example, does not satisfy formula (3) or formula (4), and it can be seen that the protective glass peels off from the frame. Example 10, as an embodiment, satisfies formula (3) or formula (4), and it can be seen that the peeling of the protective glass from the frame can be suppressed.

[0145] [Table 4] Table 4 CG thickness t (mm) CG Young's Modulus (GPa) Radius of curvature (mm) Next, calculate the area A1 (mm²). Next, calculate the area A² (mm²). Perimeter L (mm) Next, calculate the area / perimeter (mm). Can it fit? Satisfaction type 6 Actual test radius of curvature R Corrected curvature R' Bending section Short lateral flattened part Bending section Short lateral flattened part Bending section Long lateral flat part Short lateral flattened part F Example 11 1.1 74 1200 1200 0 0 3950 0 250 0 0 15.8 A 1.1 74 1000 1000 0 0 3950 0 250 0 0 15.8 A 1.1 74 800 800 0 0 3750 0 250 0 0 15.1 A have 1.1 74 600 600 0 0 10930 0 250 0 0 43.7 A 1.1 74 600 600 0 0 7480 0 250 0 0 29.9 A have 1.1 74 400 400 0 0 15500 0 250 0 0 62.0 A Example 12 1.1 74 800 800 0 0 2290 0 250 0 0 9.2 B 1.1 74 800 800 0 0 770 0 250 0 0 3.1 B 1.1 74 600 600 0 0 3750 0 250 0 0 15.0 B have 1.1 74 400 400 0 0 10780 0 250 0 0 43.1 B 1.1 74 400 400 0 0 8490 0 250 0 0 34.0 B 1.1 74 400 400 0 0 7500 0 250 0 0 30.0 B have 1.1 74 400 400 0 0 5780 0 250 0 0 23.1 B 1.1 74 600 600 0 0 3750 0 250 100 0 15.0 B have 1.1 74 600 600 0 0 3750 0 250 150 0 15.0 B

[0146] (Example 11, Example 12) Table 4 shows the characteristics of the protective glass in Examples 11 and 12. Figure 26 is a graph showing the evaluation results of each protective glass in Examples 11 and 12. In Examples 11 and 12, the same as in Examples 1 and 2 were used, except that an adhesive equivalent to the second adhesive layer (3M double-sided tape VHX-1701-04) was used as the adhesive layer, and the radius of curvature R, area A2, and perimeter L were set as shown in Table 4. As shown in Table 4 and Figure 26, Example 12, as a comparative example, does not satisfy formula (3) or formula (4), and it can be seen that the protective glass peels off from the frame. Example 11, as an embodiment, satisfies formula (3) or formula (4), and it can be seen that the peeling of the protective glass from the frame can be suppressed.

[0147] [Table 5] Table 5 CG thickness t (mm) CG Young's Modulus (GPa) Radius of curvature (EE) Next, calculate the area A1 (mm²). Next, calculate the area A² (mm²). Perimeter L (mm) Next, calculate the area / perimeter (mm). Can it fit? Satisfaction type 6 Actual test radius of curvature R Corrected curvature R' Bending section Short lateral flattened part Bending section Short lateral flattened part Bending section Long lateral flat part Short lateral flattened part F Example 13 1.1 74 600 702 0 0 2325 118 250 20 20 9.0 B 1.1 74 600 855 0 0 2325 295 250 50 50 8.7 B 1.1 74 400 655 0 0 3039 845.5 250 50 50 12.9 B have 1.1 74 400 655 0 0 1417 721.5 250 50 50 7.1 B 1.1 74 600 855 0 0 2325 295 250 100 50 8.7 B 1.1 74 600 1110 0 0 902 136.5 250 100 100 3.0 B Example 14 1.1 74 600 855 0 0 5234 728 250 50 50 19.9 A 1.1 74 400 655 0 0 15038 1366 250 50 50 54.7 A 1.1 74 400 655 0 0 7094 1353 250 50 50 28.2 A Yes 1.1 74 400 655 0 0 5780 845 250 50 50 22.1 A 1.1 74 600 1110 0 0 3750 1025 250 100 100 13.6 A 1.1 74 600 1110 0 0 2325 588 250 100 100 8.3 A 1.1 74 400 910 0 0 15038 3271 250 100 100 52.3 A fullness 1.1 74 400 910 0 0 7094 2478 250 100 100 27.3 A 1.1 74 600 1365 0 0 2325 883 250 150 150 8.0 A 1.1 74 400 1165 0 0 15038 5176 250 150 150 50.5 A satisfy 1.1 74 400 1165 0 0 7094 3398 250 150 150 26.2 A satisfy

[0148] (Example 13, Example 14) Table 5 shows the characteristics of the protective glass in Examples 13 and 14. Figure 27 is a graph showing the evaluation results of each protective glass in Examples 13 and 14. In Examples 13 and 14, the process is the same as in Examples 11 and 12, except that a portion of the protective glass is bent and flat portions are formed on both sides of the bent portion, and the radius of curvature R, area A2, and perimeter L are set as shown in Table 5. As shown in Table 5 and Figure 27, Example 13, as a comparative example, does not satisfy formula (3) or formula (4), and it can be seen that the protective glass peels off from the frame. Example 14, as an embodiment, satisfies formula (3) or formula (4), and it can be seen that the peeling of the protective glass from the frame can be suppressed. Furthermore, some samples in Example 14 further satisfy equation (6).

[0149] [Table 6] Table 6 CG thickness t (mm) CG Young's Modulus (GPa) Radius of curvature (mm) Next, calculate the area A1 (mm²). Next, calculate the area A² (mm²). Perimeter L (mm) Next, calculate the area / perimeter (mm). Can it fit? Satisfaction type 6 Actual test radius of curvature R Corrected curvature R' Bending section Short lateral flattened part Bending section Short lateral flattened part Bending section Long lateral flat part Short lateral flattened part F Example 15 0.7 74 200 200 0 0 6510 0 250 0 0 26.0 B have 0.7 74 200 200 0 0 3482 0 250 0 0 13.9 B Example 16 0.7 74 400 400 0 0 7600 0 250 0 0 30.4 A fullness 0.7 74 400 400 0 0 3900 0 250 0 0 15.6 A 0.7 74 200 200 0 0 13010 0 250 0 0 52.0 A 0.7 74 200 200 0 0 10490 0 250 0 0 42.0 A Example 17 0.7 74 200 262 0 0 3482 159 250 20 20 13.5 B Example 18 0.7 74 200 290 0 0 3482 231 250 29 29 13.3 A 0.7 74 200 340 0 0 4404 310 250 45 45 16.0 A Example 19 0.5 74 200 200 0 0 710 0 250 0 0 2.8 B Example 20 0.5 74 400 400 0 0 796 0 250 0 0 3.2 A satisfy 0.5 74 200 200 0 0 6510 0 250 0 0 26.0 A 0.5 74 200 200 0 0 3330 0 250 0 0 13.3 A Example 41 1.1 70 600 600 0 0 4500 0 250 0 0 18.0 A Example 42 1.1 70 600 600 0 0 2328 0 250 0 0 9.3 B Example 43 1.1 77 600 600 0 0 7000 0 250 0 0 28.0 A Example 44 1.1 77 600 600 0 0 3750 0 250 0 0 15.0 B

[0150] (Example 15, Example 16) Table 6 shows the characteristics of the protective glass in Examples 15 to 20 and Examples 41 to 44. Figure 28 is a graph showing the evaluation results of each protective glass in Examples 15 and 16. In Examples 15 and 16, the thickness of the protective glass is set to 0.7 mm, and the radius of curvature R, area A2, and perimeter L are set as shown in Table 6, which is the same as in Examples 11 and 12. As shown in Table 6 and Figure 28, Example 15, as a comparative example, does not satisfy Equation (3) or Equation (4), and it can be seen that the protective glass peels off from the frame. Example 16, as an embodiment, satisfies Equation (3) or Equation (4), and it can be seen that the peeling of the protective glass from the frame can be suppressed. Furthermore, some samples in Example 16 further satisfy equation (6).

[0151] (Example 17, Example 18) Figure 29 is a graph showing the evaluation results of the protective glass in Examples 17 and 18. In Examples 17 and 18, the curvature radius R, area A2, and perimeter L are the same as in Examples 15 and 16, except that a portion of the protective glass is bent and flat portions are formed on both sides of the bent portion, and the curvature radius R, area A2, and perimeter L are set as shown in Table 6. As shown in Table 6 and Figure 29, Example 17, as a comparative example, does not satisfy Equation (3) or Equation (4), and it can be seen that the protective glass peels off from the frame. Example 18, as an embodiment, satisfies Equation (3) or Equation (4), and it can be seen that the peeling of the protective glass from the frame can be suppressed.

[0152] (Example 19, Example 20) Figure 30 is a graph showing the evaluation results of each protective glass in Examples 19 and 20. In Examples 19 and 20, the thickness of the protective glass is set to 0.5 mm, and the radius of curvature R, area A2, and perimeter L are set as shown in Table 6, which is the same as in Examples 11 and 12. As shown in Table 6 and Figure 30, Example 19, as a comparative example, does not satisfy Equation (3) or Equation (4), and it can be seen that the protective glass peels off from the frame. Example 20, as an embodiment, satisfies Equation (3) or Equation (4), and it can be seen that the peeling of the protective glass from the frame can be suppressed. Furthermore, a portion of the samples in Example 20 further satisfy equation (6).

[0153] (Examples 41~44) Figures 41 and 42 are graphs showing the evaluation results of each protective glass in Examples 41 to 44. Examples 41-44 are the same as Examples 11 and 12, except that the Young's modulus of the glass plate is set to 70 GPa or 77 GPa, and the radius of curvature R, area A2, and perimeter L are set as shown in Table 6. As shown in Table 6 and Figures 41 and 42, Examples 42 and 44, which are comparative examples, do not satisfy Equation (3) or Equation (4), and it can be seen that the protective glass peels off from the frame. Examples 41 and 43, which are embodiments, satisfy Equation (3) or Equation (4), and it can be seen that the peeling of the protective glass from the frame can be suppressed.

[0154] [Table 7] Table 7 CG thickness t (mm) Radius of curvature (mm) Next, calculate the area A1 (mm²). Next, calculate the area A² (mm²). Circumference (mm) Next, calculate the area / perimeter (mm). Can it fit? Actual test radius of curvature R Corrected curvature R' Bending section Short lateral flattened part Bending section Short lateral flattened part Bending section Long lateral flat part Short lateral flat part F Example 21 1.1 600 600 5806 0 0.0 0.0 250 0 0 23.2 B 1.1 600 600 4424 0 0.0 0.0 250 0 0 17.7 B 1.1 800 800 3079 0.0 0.0 0.0 250 0 0 12.3 B 1.1 600 600 2784 0 0.0 0.0 250 0 0 11.1 B 1.1 1000 1000 1599 0.0 0.0 0.0 250 0 0 6.4 B 1.1 800 800 1579 0.0 0.0 0.0 250 0 0 6.3 B 1.1 800 800 640 0.0 0.0 0.0 250 0 0 2.6 B Example 22 1.1 800 800 4498 0.0 0.0 0.0 250 0 0 18.0 A 1.1 1000 1000 3116 0.0 0.0 0.0 250 0 0 12.5 A Example 23 1.1 1000 1000 0 0 7600 0.0 250 0 0 30.4 A 1.1 800 800 0 0 10970 0.0 250 0 0 43.9 A Example 24 1.1 1000 1000 0 0 3900 0.0 250 0 0 15.6 B have 1.1 800 800 0 0 7510 0.0 250 0 0 30.0 B have 1.1 800 800 0 0 3850 0.0 250 0 0 15.4 B have 1.1 800 800 0 0 1560 0.0 250 0 0 6.2 B 1.1 600 600 0 0 14160 0 250 0 0 56.6 B 1.1 600 600 0 0 10790 0 250 0 0 43.2 B 1.1 600 600 0 0 6790 0 250 0 0 27.2 B have

[0155] (Example 21, Example 22) Table 7 shows the characteristics of the protective glass in Examples 21 to 24. Figure 31 is a graph showing the evaluation results of each protective glass in Examples 21 and 22. In Examples 21 and 22, the curvature radius R, area A2, and perimeter L are the same as in Examples 1 and 2, except that the curvature radius R, area A2, and perimeter L are set as shown in Table 7, with the curvature convex in the lateral direction (X direction) on the side not attached to the frame (the first main surface side). As shown in Table 7 and Figure 31, Example 21, as a comparative example, does not satisfy Equation (6) or Equation (7), and it can be seen that the protective glass peels off from the frame. Example 22, as an embodiment, satisfies Equation (6) or Equation (7), and it can be seen that the peeling of the protective glass from the frame can be suppressed.

[0156] (Example 23, Example 24) Figure 32 is a graph showing the evaluation results of the protective glass in Examples 23 and 24. In Examples 23 and 24, the same as in Examples 21 and 22 were used, except that an adhesive equivalent to the second adhesive layer (3M double-sided tape VHX-1701-04) was used as the adhesive layer, and the radius of curvature R, area A2, and perimeter L were set as shown in Table 7. As shown in Table 7 and Figure 32, Example 24, as a comparative example, does not satisfy Equation (6) or Equation (7), indicating that the protective glass peels off from the frame. Example 23, as an embodiment, satisfies Equation (6) or Equation (7), indicating that the peeling of the protective glass from the frame can be suppressed.

[0157] [Table 8] Table 8 CG thickness t (mm) Radius of curvature (mm) Next, calculate the area A1 (mm²). Next, calculate the area A² (mm²). Circumference (mm) Next, area / perimeter (mm) Can it fit? Actual test radius of curvature R Corrected curvature R' Bending section Short lateral flattened part Bending section Short lateral flattened part Bending section Long lateral flat part Short lateral flat part F Example 25 1.1 600 702 0 0 6790 585 250 20 20 27.3 B 1.1 600 855 0 0 5421 1065 250 50 50 21.6 B 1.1 600 855 0 0 3210 785 250 50 50 13.3 B 1.1 600 1110 0 0 999 661 250 100 100 4.7 B Example 26 1.1 600 855 0 0 10790 1485 250 50 50 40.9 A Yes 1.1 600 1110 0 0 6790 1975 250 100 100 25.0 A 1.1 600 1365 0 0 6790 3220 250 150 150 25.0 A 1.1 600 1365 0 0 3210 1750 250 150 150 12.4 A Example 27 1.1 600 1110 410 271 0.0 0.0 250 100 100 1.9 B 1.1 600 855 1316 322 0.0 0.0 250 50 50 5.5 B 1.1 600 855 2223 436 0.0 0.0 250 50 50 8.9 B 1.1 600 702 2784 240 0.0 0.0 250 20 20 11.2 B Example 28 1.1 600 1365 1316 718 0.0 0.0 250 150 150 5.1 A 1.1 600 1110 2784 810 0.0 0.0 250 100 100 10.3 A 1.1 600 1365 2784 1320 0.0 0.0 250 150 150 10.3 A 1.1 600 855 4424 609 0.0 0.0 250 50 50 16.8 A

[0158] (Example 25, Example 26) Table 8 shows the characteristics of the protective glass in Examples 25 to 28. Figure 33 is a graph showing the evaluation results of each protective glass in Examples 25 and 26. In Examples 25 and 26, the curvature radius R, area A2, and perimeter L are the same as in Examples 23 and 24, except that a portion of the protective glass is bent and flat portions are formed on both sides of the bent portion, and the curvature radius R, area A2, and perimeter L are set as shown in Table 7. As shown in Table 8 and Figure 33, Example 25, as a comparative example, does not satisfy Equation (6) or Equation (7), and it can be seen that the protective glass peels off from the frame. Example 26, as an embodiment, satisfies Equation (6) or Equation (7), and it can be seen that the peeling of the protective glass from the frame can be suppressed.

[0159] (Example 27, Example 28) Figure 34 is a graph showing the evaluation results of the protective glass in Examples 27 and 28. In Examples 27 and 28, the curvature radius R, area A2, and perimeter L are the same as in Examples 21 and 22, except that a portion of the protective glass is bent and flat portions are formed on both sides of the bent portion, and the curvature radius R, area A2, and perimeter L are set as shown in Table 7. As shown in Table 8 and Figure 34, Example 27, as a comparative example, does not satisfy Equation (6) or Equation (7), and it can be seen that the protective glass peels off from the frame. Example 28, as an embodiment, satisfies Equation (6) or Equation (7), and it can be seen that the peeling of the protective glass from the frame can be suppressed.

[0160] [Table 9] Table 9 CG thickness t (mm) Radius of curvature (mm) Next, calculate the area A1 (mm²). Next, calculate the area A² (mm²). Circumference (mm) Next, area / perimeter (mm) Can it fit? Actual test radius of curvature R Corrected curvature R' Bending section Short lateral flattened part Bending section Short lateral flattened part Bending section Long lateral flat part Short lateral flat part F Example 29 0.7 400 400 0 0 3770 0 250 0 0 15.1 B have 0.7 400 400 0 0 1530 0 250 0 0 6.1 B 0.7 200 200 0 0 12970 0 250 0 0 51.9 B Example 30 0.7 400 400 0 0 13970 0 250 0 0 55.9 A 0.7 400 400 0 0 10760 0 250 0 0 43.0 A 0.7 400 400 0 0 7360 0 250 0 0 29.4 A have Example 31 0.7 200 262 0 0 3242 274 250 20 20 13.0 B Example 32 0.7 200 355 0 0 11980 685 250 50 50 42.2 A Example 33 0.7 400 400 627 0 0.0 0.0 250 0 0 2.5 B 0.7 400 400 1546 0 0.0 0.0 250 0 0 6.2 B 0.7 200 200 5318 0 0.0 0.0 250 0 0 21.3 B Example 34 0.7 400 400 3018 0 0.0 0.0 250 0 0 12.1 A 0.7 400 400 4412 0 0.0 0.0 250 0 0 17.6 A 0.7 400 400 5728 0 0.0 0.0 250 0 0 22.9 A Example 35 0.7 200 262 1329 112 0.0 0.0 250 20 20 5.3 B Example 36 0.7 200 355 4912 281 0.0 0.0 250 50 50 17.3 A

[0161] (Example 29, Example 30) Table 9 shows the characteristics of the protective glass in Examples 29 to 36. Figure 35 is a graph showing the evaluation results of each protective glass in Examples 29 and 30. In Examples 29 and 30, the thickness of the protective glass is set to 0.7 mm, and the radius of curvature R, area A2, and perimeter L are set as shown in Table 9, which is the same as in Examples 23 and 24. As shown in Table 9 and Figure 35, Example 29, as a comparative example, does not satisfy Equation (6) or Equation (7), indicating that the protective glass peels off from the frame. Example 30, as an embodiment, satisfies Equation (6) or Equation (7), indicating that the peeling of the protective glass from the frame can be suppressed.

[0162] (Example 31, Example 32) Figure 36 is a graph showing the evaluation results of the protective glass in Examples 31 and 32. In Examples 31 and 32, except that a portion of the protective glass is bent and flat portions are formed on both sides of the bent portion, and the radius of curvature R, area A2, and perimeter L are set as shown in Table 9, the results are the same as in Examples 29 and 30. As shown in Table 9 and Figure 36, Example 31, as a comparative example, does not satisfy Equation (6) or Equation (7), and it can be seen that the protective glass peels off from the frame. Example 32, as an embodiment, satisfies Equation (6) or Equation (7), and it can be seen that the peeling of the protective glass from the frame can be suppressed.

[0163] (Example 33, Example 34) Figure 37 is a graph showing the evaluation results of the protective glass in Examples 33 and 34. In Examples 33 and 34, the thickness of the protective glass is set to 0.7 mm, and the radius of curvature R, area A2, and perimeter L are set as shown in Table 9, which are the same as in Examples 21 and 22. As shown in Table 9 and Figure 37, Example 33, as a comparative example, does not satisfy Equation (6) or Equation (7), and it can be seen that the protective glass peels off from the frame. Example 34, as an embodiment, satisfies Equation (6) or Equation (7), and it can be seen that the peeling of the protective glass from the frame can be suppressed.

[0164] (Example 35, Example 36) Figure 38 is a graph showing the evaluation results of the protective glass in Examples 35 and 36. In Examples 35 and 36, except that a portion of the protective glass is bent and flat portions are formed on both sides of the bent portion, and the radius of curvature R, area A2, and perimeter L are set as shown in Table 9, the results are the same as in Examples 33 and 34. As shown in Table 9 and Figure 38, Example 35, as a comparative example, does not satisfy Equation (6) or Equation (7), and it can be seen that the protective glass peels off from the frame. Example 36, as an embodiment, satisfies Equation (6) or Equation (7), and it can be seen that the peeling of the protective glass from the frame can be suppressed.

[0165] [Table 10] Table 10 CG thickness t (mm) Radius of curvature (mm) Next, calculate the area A1 (mm²). Next, calculate the area A² (mm²). Circumference (mm) Next, calculate the area / perimeter (mm). Can it fit? Actual test radius of curvature R Corrected curvature R' Bending section Short lateral flattened part Bending section Short lateral flattened part Bending section Long lateral flat part Short lateral flat part F Example 37 0.5 200 200 0 0 9960 0 250 0 0 39.84 B 0.5 200 200 0 0 6790 0 250 0 0 27.16 B 0.5 200 200 0 0 3470 0 250 0 0 13.88 B Example 38 0.5 400 400 0 0 13970 0 250 0 0 55.88 A 0.5 400 400 0 0 10530 0 250 0 0 42.12 A 0.5 400 400 0 0 7020 0 250 0 0 28.08 A 0.5 400 400 0 0 3610 0 250 0 0 14.44 A 0.5 200 200 0 0 13970 0 250 0 0 55.88 A Example 39 0.5 200 200 1423 0 0.0 0.0 250 0 0 5.7 B 0.5 200 200 2784 0 0.0 0.0 250 0 0 11.1 B 0.5 200 200 4084 0 0.0 0.0 250 0 0 16.3 B Example 40 0.5 400 400 1480 0 0.0 0.0 250 0 0 5.9 A 0.5 400 400 2878 0 0.0 0.0 250 0 0 11.5 A 0.5 400 400 4317 0 0.0 0.0 250 0 0 17.3 A 0.5 400 400 5728 0 0.0 0.0 250 0 0 22.9 A 0.5 200 200 5728 0 0.0 0.0 250 0 0 22.9 A

[0166] (Example 37, Example 38) Table 10 shows the characteristics of the protective glass in Examples 37 to 40. Figure 39 is a graph showing the evaluation results of the protective glass in Examples 37 and 38. In Examples 37 and 38, the thickness of the protective glass is set to 0.5 mm, and the radius of curvature R, area A2, and perimeter L are set as shown in Table 9, which are the same as in Examples 23 and 24. As shown in Table 10 and Figure 39, Example 37, as a comparative example, does not satisfy Equation (6) or Equation (7), and it can be seen that the protective glass peels off from the frame. Example 38, as an embodiment, satisfies Equation (6) or Equation (7), and it can be seen that the peeling of the protective glass from the frame can be suppressed.

[0167] (Example 39, Example 40) Figure 40 is a graph showing the evaluation results of the protective glass in Examples 39 and 40. In Examples 39 and 40, the thickness of the protective glass is set to 0.5 mm, and the radius of curvature R, area A2, and perimeter L are set as shown in Table 9, which are the same as in Examples 21 and 22. As shown in Table 10 and Figure 40, Example 39, as a comparative example, does not satisfy Equation (6) or Equation (7), indicating that the protective glass peels off from the frame. Example 40, as an embodiment, satisfies Equation (6) or Equation (7), indicating that the peeling of the protective glass from the frame can be suppressed.

[0168] While the embodiments of the present invention have been described above, they are not intended to limit the scope of the embodiments. Furthermore, the aforementioned constituent elements include elements readily conceived by those skilled in the art, substantially identical elements, and elements within a so-called equal range. Moreover, the aforementioned constituent elements can be suitably combined. Furthermore, various omissions, substitutions, or modifications of the constituent elements can be made without departing from the essence of the aforementioned embodiments.

[0169] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that changes or modifications can be made without departing from the spirit and scope of the invention. Furthermore, this application is based on and incorporates the contents of Japanese Patent Application No. 2021-139604, filed August 30, 2021, and Japanese Patent Application No. 2022-072684, filed April 26, 2022.

[0170] 1: Steering shaft 2: Vehicle-mounted display device 3: Monitor 10: Glass items 12: Protective Glass 12A, 12B: Main face 12C1, 12C2, 12C3, 12C4: Side view 14: Frame 16: Next layer 20, 20A, 20a, 20B: Curved section 20C, 20D, 20D', 20N: Location 20J, 20K, 20L, 20M: Endpoints 20P, 20Q: End Edge 20R: Arc 22: Flat area A 1, A 2: area AR: Following the area / region AR0: Area AR1: The first layer AR2: The second layer F: Length L: Perimeter P: Location / Point R, R1, R2: Radius of curvature R': Corrected radius of curvature / Corrected curvature R'0: value S: Section t: thickness X, Y: Direction YA: Bending axis / line segment YB: Bending shaft Z: Direction α,β: plane

Claims

1. A glass article comprising: a protective glass having a first main surface and a second main surface; and a frame attached to the second main surface of the protective glass via an adhesive layer; and a curved portion convex toward the second main surface of the protective glass; wherein the adhesive layer comprises at least one of a first adhesive layer having an elastic modulus of 5 MPa or more in an indentation modulus test and a second adhesive layer having an elastic modulus of less than 5 MPa in an indentation modulus test; wherein when R' is set as shown in formula (1) and C1 is set as shown in formula (2), the curved portion satisfies formula (3) when C1 > 0 and formula (4) when C1 ≦ 0: [Number 1] [Number 2] [Number 3] [Number 4] Here, R is the radius of curvature (mm) of the curved portion; F represents the length of the flat area in the first direction of the aforementioned direction when the protective glass has a flat area adjacent to the first direction orthogonal to the bending axis of the aforementioned curved portion; t represents the thickness of the aforementioned protective glass (mm); A1 represents the area of ​​the first bonding layer in the aforementioned curved portion (mm2); A2 represents the area of ​​the second bonding layer in the aforementioned curved portion (mm2); E represents the Young's modulus (GPa) of the aforementioned protective glass; L represents the length of the aforementioned curved portion in the first direction (mm).

2. For the glass article of claim 1, the curved portion convex towards the aforementioned second main surface further satisfies the following formula (6) when C1 > 0. [Col. 5] 3. For the glass article of claim 1 or 2, wherein the aforementioned protective glass is further provided with a curved portion convex towards the aforementioned first main surface; and when C2 is set as shown in equation (5), the curved portion convex towards the aforementioned first main surface satisfies equation (6) when C2 > 0, and satisfies equation (7) when C2 ≦ 0. [Number 6] [Number 7] [Number 8] 4. A glass article comprising: a protective glass having a first main surface and a second main surface; and a frame attached to the second main surface of the protective glass via an adhesive layer; and a curved portion convex toward the first main surface of the protective glass; the adhesive layer comprising at least one of a first adhesive layer having an elastic modulus of 5 MPa or more in an indentation elastic modulus test and a second adhesive layer having an elastic modulus of less than 5 MPa in an indentation elastic modulus test; when R' is set as shown in formula (1) and C2 is set as shown in formula (5), the curved portion satisfies formula (6) when C2 > 0 and formula (7) when C2 ≦ 0: [Number 9] [Number 10] [Number 11] [Number 12] Here, R is the radius of curvature (mm) of the curved portion; F represents the length of the flat area in the first direction of the aforementioned direction when the protective glass has a flat area adjacent to the first direction orthogonal to the bending axis of the aforementioned curved portion; t represents the thickness of the aforementioned protective glass (mm); A1 represents the area of ​​the first bonding layer in the aforementioned curved portion (mm2); A2 represents the area of ​​the second bonding layer in the aforementioned curved portion (mm2); E represents the Young's modulus (GPa) of the aforementioned protective glass; L represents the length of the aforementioned curved portion in the first direction (mm).

5. A glass article as claimed in any of claims 1, 2 or 4, wherein the aforementioned flat areas are provided on both sides of the aforementioned curved portion in the first direction.

6. Glass articles as requested in any of items 1, 2 or 4, wherein the aforementioned (A1+A2) / L is 80 mm or less.

7. Glass articles as claimed in item 6, wherein the aforementioned (A1+A2) / L is 60 mm or less.

8. A glass article as claimed in any of claims 1, 2 or 4, wherein the aforementioned adhesive layer comprises both the aforementioned first adhesive layer and the aforementioned second adhesive layer, the aforementioned first adhesive layer and the aforementioned second adhesive layer being composed of different adhesive components.

9. Glass articles as claimed in any of items 1, 2 or 4, wherein the thickness of the aforementioned protective glass, i.e., t, is more than 0.3 mm and less than 3.0 mm.

10. A glass article as claimed in any of items 1, 2 or 4, wherein the radius of curvature R of the aforementioned curved portion is more than 50 mm and less than 10,000 mm.

11. Glass articles as claimed in any of items 1, 2 or 4, wherein the Young's modulus, E, of the aforementioned protective glass is 60 GPa or more and 90 GPa or less.

12. A vehicle-mounted display device comprising: a display screen and a glass article disposed on the surface of the display screen, as claimed in any one of claims 1 to 11.

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