Glass article and onboard display device

Abstract

To prevent cover glass from separating from a frame.SOLUTION: A glass article 10 includes cover glass 12 and a frame 14 to be adhered onto a principal surface 12B side of the cover glass 12, interposing an adhesion layer 16. The cover glass 12 is provided with a curved part having a convex shape in a direction of the principal surface 12B. The adhesion layer 16 includes at least one of a first adhesion layer and a second adhesion layer. A prescribed relation is satisfied by thickness of the cover glass, Young's modulus, a peripheral length, a curvature radius of the curved part and an area of the adhesion layer.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a glass article and an in-vehicle display device. [Background technology]

[0002] Liquid crystal displays and organic electroluminescence displays are sometimes used in in-vehicle display devices that display information necessary during driving. These displays may be provided with a cover glass to protect the front surface. In recent years, high design quality has been required for the interior of a vehicle, and curved cover glass is in demand. As one method for bending and forming a cover glass, for example, a cold forming method as described in Patent Document 1 is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2017-532233 Summary of the Invention [Problem to be solved by the invention]

[0004] However, for example, in the case of a cover glass bent by a cold forming method, the curved shape is maintained by fixing the cover glass to the frame with an adhesive, so there is a risk that the cover glass will peel off from the frame due to spring back.

[0005] The present invention has been made in consideration of the above problems, and has an object to provide a glass article and an in-vehicle display device that can prevent the cover glass from peeling off from the frame. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, a glass article according to the present disclosure comprises a cover glass having a first main surface and a second main surface, and a frame adhered to the second main surface side of the cover glass via an adhesive layer, the cover glass being provided with a curved portion that is convex toward the second main surface, the adhesive layer including 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, wherein, when R' is as shown in the following formula (1) and C1 is 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.

[0007] In the following formula, R is the radius of curvature (mm) of the curved portion, F is the length of the flat region in a first direction perpendicular to the bending axis of the curved portion when the flat region is provided adjacent to the curved portion in the first direction, t is the thickness (mm) of the cover glass, and A1 is the area (mm) of the first adhesive layer in the curved portion. 2 ), and A2 is the area (mm 2 ), E is the Young's modulus (GPa) of the cover glass, and L is the length (mm) of the curved portion in the first direction.

[0008]

number

[0009]

number

[0010]

number

[0011]

number

[0012] In order to solve the above-mentioned problems and achieve the object, a glass article according to the present disclosure comprises a cover glass having a first main surface and a second main surface, and a frame adhered to the second main surface side of the cover glass via an adhesive layer, the cover glass being provided with a curved portion that is convex toward the first main surface, the adhesive layer including 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, wherein, when R' is as shown in the following formula (1) and C2 is 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.

[0013] In the following formula, R is the radius of curvature (mm) of the curved portion, F is the length of the flat region in a first direction perpendicular to the bending axis of the curved portion when the flat region is provided adjacent to the curved portion in the first direction, t is the thickness (mm) of the cover glass, and A1 is the area (mm) of the first adhesive layer in the curved portion. 2 ), and A2 is the area (mm 2 ), E is the Young's modulus (GPa) of the cover glass, and L is the length (mm) of the curved portion in the first direction.

[0014]

number

[0015]

number

[0016]

number

[0017]

number

[0018] In order to solve the above-mentioned problems and achieve the object, an in-vehicle display device according to the present disclosure includes a display and the glass article provided on a surface of the display. Effect of the Invention

[0019] According to the present invention, it is possible to prevent the cover glass from peeling off from the frame. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic diagram showing an in-vehicle display device according to the present embodiment. [Diagram 2] FIG. 2 is a schematic diagram of a glass article according to this embodiment. [Diagram 3] FIG. 3 is a top view of the cover glass. [Figure 4] FIG. 4 is a cross-sectional view of a cover glass. [Diagram 5] FIG. 5 is an example of a graph illustrating the relationship between the characteristics of the cover glasses. [Figure 6] FIG. 6 is a diagram showing an example in which both the first adhesive layer and the second adhesive layer are provided. [Figure 7] FIG. 7 is a schematic diagram of a cover glass according to another example of this embodiment. [Figure 8] FIG. 8 is a schematic diagram of a cover glass according to another example of this embodiment. [Figure 9] FIG. 9 is a schematic diagram of a cover glass according to another example of this embodiment. [Figure 10] FIG. 10 is a schematic diagram of a cover glass according to another example of this embodiment. [Figure 11] FIG. 11 is a schematic diagram of a cover glass according to another example of this embodiment. [Figure 12] FIG. 12 is a schematic diagram of a cover glass according to another example of this embodiment. [Figure 13]FIG. 13 is a schematic diagram of a cover glass according to another example of this embodiment. [Figure 14] FIG. 14 is a schematic diagram of a cover glass according to another example of this embodiment. [Figure 15] FIG. 15 is a schematic diagram of a cover glass according to another example of this embodiment. [Figure 16] FIG. 16 is a schematic diagram of a cover glass according to another example of this embodiment. [Figure 17] FIG. 17 is a schematic diagram of a cover glass according to another example of this embodiment. [Figure 18] FIG. 18 is a schematic diagram of a cover glass according to another example of this embodiment. [Figure 19] FIG. 19 is a schematic diagram of a cover glass according to another example of this embodiment. [Figure 20] FIG. 20 is a schematic diagram of a cover glass according to another example of this embodiment. [Figure 21] FIG. 21 is a graph showing the evaluation results of each of the cover glasses of Examples 1 and 2. [Figure 22] FIG. 22 is a graph showing the evaluation results of each of the cover glasses of Examples 3 and 4. [Figure 23] FIG. 23 is a graph showing the evaluation results of each of the cover glasses of Examples 5 and 6. [Figure 24] FIG. 24 is a graph showing the evaluation results of each of the cover glasses of Examples 7 and 8. [Diagram 25] FIG. 25 is a graph showing the evaluation results of each of the cover glasses of Examples 9 and 10. [Figure 26] FIG. 26 is a graph showing the evaluation results of the cover glasses of Examples 11 and 12. [Figure 27] FIG. 27 is a graph showing the evaluation results of the cover glasses of Examples 13 and 14. [Figure 28] FIG. 28 is a graph showing the evaluation results of the cover glasses of Examples 15 and 16. [Figure 29] FIG. 29 is a graph showing the evaluation results of the cover glasses of Examples 17 and 18. [Diagram 30] FIG. 30 is a graph showing the evaluation results of each of the cover glasses of Examples 19 and 20. [Diagram 31] FIG. 31 is a graph showing the evaluation results of each of the cover glasses of Examples 21 and 22. [Diagram 32] FIG. 32 is a graph showing the evaluation results of each of the cover glasses of Examples 23 and 24. [Diagram 33] FIG. 33 is a graph showing the evaluation results of the cover glasses of Examples 25 and 26. [Diagram 34] FIG. 34 is a graph showing the evaluation results of the cover glasses of Examples 27 and 28. [Diagram 35] FIG. 35 is a graph showing the evaluation results of the cover glasses of Examples 29 and 30. [Diagram 36] FIG. 36 is a graph showing the evaluation results of the cover glasses of Examples 31 and 32. [Figure 37] FIG. 37 is a graph showing the evaluation results of the cover glasses of Examples 33 and 34. [Figure 38] FIG. 38 is a graph showing the evaluation results of the cover glasses of Examples 35 and 36. [Figure 39] FIG. 39 is a graph showing the evaluation results of the cover glasses of Examples 37 and 38. [Diagram 40] FIG. 40 is a graph showing the evaluation results of the cover glasses of Examples 39 and 40. [Diagram 41] FIG. 41 is a graph showing the evaluation results of the cover glasses of Examples 41 and 42. [Diagram 42] FIG. 42 is a graph showing the evaluation results of the cover glasses of Examples 43 and 44. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Note that the present invention is not limited to this embodiment, and when there are multiple embodiments, the present invention also includes a combination of the embodiments. Numerical values ​​include the range of rounding.

[0022] (In-vehicle display device) Fig. 1 is a schematic diagram showing an in-vehicle display device according to this embodiment. As shown in Fig. 1, a glass article 10 according to this embodiment is provided in an in-vehicle display device 2 and is used as a cover material for the surface (front surface) of a display 3 on which an image is displayed.

[0023] The in-vehicle display device 2 is a display device provided in a vehicle, and is provided, for example, in front of a steering shaft 1 inside the vehicle. For example, a car navigation screen, various meters such as a speedometer, and a start button are displayed on the display 3. However, the configuration in Fig. 1 is only an example, and the in-vehicle display device 2 to which the glass article 10 is applied may have any configuration. In addition, the glass article 10 is not limited to being used as a cover material for the surface of the in-vehicle display device 2, and may be used for any purpose.

[0024] (Glass products) FIG. 2 is a schematic diagram of a glass article according to this embodiment. As shown in FIG. 2, the glass article 10 includes a cover glass 12, a frame 14, and an adhesive layer 16. The cover glass 12 is a transparent plate-like glass member, and has a main surface 12A (first main surface) which is a main surface on one side, and a main surface 12B (second main surface) which is a main surface opposite to the main surface 12A. When the glass article 10 is mounted on an object to be mounted, such as an in-vehicle display device 2, the main surface 12A of the cover glass 12 becomes the side exposed to the outside, and the main surface 12B becomes the side facing the object to be mounted (here, the display 3). Note that the term "transparent" here refers to being transparent to visible light.

[0025] The frame 14 is a frame-shaped member attached to the main surface 12B of the cover glass 12. The frame 14 is made of, for example, resin or metal, but is not limited thereto and may be made of any material. Since the cover glass 12 is curved in the X direction (first direction) as described below, the frame 14 is also curved in the X direction along the cover glass 12. The frame 14 is attached to the peripheral portion of the main surface 12B of the cover glass 12.

[0026] 2, the frame 14 is provided over the entire circumferential section of the peripheral portion of the main surface 12B of the cover glass 12, but is not limited thereto and may be interrupted in a portion of the circumferential section. Also, in the example of FIG. 2, the peripheral end of the cover glass 12 does not protrude from the frame 14, but is not limited thereto and may be the peripheral end of the cover glass 12 protruding from the frame 14.

[0027] 2, frame 14 is provided on the periphery of cover glass 12 and has a frame shape with an opening on the inside, but frame 14 may also have a box shape without an opening. That is, a plate-shaped member that covers the opening may be provided on the Z direction side of frame 14 in Fig. 2. In this way, the shape of frame 14 and the attachment position on main surface 12B are not limited to those described above and may be arbitrary.

[0028] The frame 14 is fixed (adhered) to the main surface 12B of the cover glass 12 via an adhesive layer 16. That is, the adhesive layer 16 is provided between the frame 14 and the main surface 12B of the cover glass 12, and adheres the surface of the frame 14 facing the cover glass 12 to the main surface 12B of the cover glass 12. The adhesive layer 16 may be composed of any adhesive member capable of adhering the frame 14 and the cover glass 12 together, such as double-sided tape or adhesive.

[0029] The glass article 10 includes at least one of a first adhesive layer and a second adhesive layer as the adhesive layer 16. The first adhesive layer refers to an adhesive layer having an elastic modulus of 5 MPa or more in an indentation elastic modulus test, and the second adhesive layer refers to an adhesive layer having an elastic modulus of less than 5 MPa in an indentation elastic modulus test. That is, the indentation elastic modulus of the first adhesive layer is higher than that of the second adhesive layer. The first adhesive layer preferably has an elastic modulus of less than 100 MPa in an indentation elastic modulus test, and more preferably has an elastic modulus of less than 30 MPa. Here, the elastic modulus of the first contact layer in an indentation elastic modulus test is preferably 5 MPa or more and less than 100 MPa, and more preferably 5 MPa or more and less than 30 MPa. The second adhesive layer preferably has an elastic modulus of 0.2 MPa or more in an indentation elastic modulus test, and more preferably 0.5 MPa or more. Here, the elastic modulus of the second contact layer in an indentation elastic modulus test is preferably 0.2 MPa or more and less than 5 MPa, and more preferably 0.5 MPa or more and less than 5 MPa.

[0030] The first adhesive layer and the second adhesive layer are composed of different adhesive members. The adhesive member constituting the first adhesive layer has a higher adhesive strength than the adhesive member constituting the second adhesive layer. The adhesive layer 16 may be composed of three or more types of adhesive members.

[0031] The indentation elastic modulus test in this embodiment is carried out in the following manner. The adhesive layer 16 bonded to the main surface 12B of the cover glass 12 and the frame 14 is exposed facing vertically upward and placed in a creep meter (e.g., model RE2-33005C, manufactured by Yamaden Corporation). A plunger (e.g., cylindrical plunger model P-61, φ1.5, H40, manufactured by Yamaden Corporation) is pressed into the adhesive layer 16 at a pressing speed of 0.05 mm / sec in an environment of room temperature, e.g., 20°C, and a relative humidity of 50%, until the pressing depth reaches 5% to 10% of the thickness of the adhesive layer 16.

[0032] The method of exposing the adhesive layer is not particularly limited, but a method that does not denature the adhesive is preferable. For example, a metal thin plate or the like is inserted between the first adhesive layer and the adherend, which is the cover glass 12 or the frame 14, to physically peel them off. If the adhesive layer breaks in the middle of the thickness direction during the peeling, it is preferable to measure the elastic modulus of the thicker remaining part. It is also preferable to measure the elastic modulus using the adhesive layer remaining on the side with the higher Young's modulus between the frame 14 and the cover glass 12. That is, it is preferable to measure the elastic modulus by leaving the adhesive layer on the frame side when the frame is made of metal, and on the cover glass side when the frame is made of resin with a low Young's modulus.

[0033] Next, the load acting on the plunger when it is pressed and the amount of displacement of the plunger in the pressing direction are measured sequentially, the load and the amount of displacement are plotted for each time, and the slope of the approximation line of each plotted point is calculated as the elastic modulus of the adhesive layer 16. This indentation elastic modulus test is performed for each position of the adhesive layer 16, and the region where the elastic modulus is 5 MPa or more is the first adhesive layer, and the region where the elastic modulus is less than 5 MPa is the second adhesive layer. It is preferable to plot every 0.04 seconds and perform the indentation elastic modulus test twice at the same position. The position where the elastic modulus is 5 MPa or more in both of the two measurements may be the first adhesive layer, and the position where the elastic modulus is less than 5 MPa in both of the two measurements may be the second adhesive layer.

[0034] Here, the meaning of the indentation elastic modulus test in the present invention will be explained. In glass articles, an adhesive bonds a glass surface or a printed surface on a glass surface to a metal or resin frame. When an attempt is made to peel off an adhered glass surface from an object, the adhesive is generally designed so that the adhesive breaks and peels off. It is known that the adhesive strength when the adhesive breaks depends on the tensile elastic modulus of the adhesive. However, it is difficult to measure glass articles in a state in which a cover glass and a frame are bonded with each other in the existing adhesive strength tests such as the cross-shaped adhesive strength test and the H-shaped adhesive strength test method. In the present invention, as an evaluation method to replace the existing adhesive strength test, an indentation elastic modulus test that can be verified even from a glass article in a state in which a cover glass and a frame are bonded is adopted. In the present invention, since it is known that the adhesive breaks when a glass article and a frame are peeled off, and that there is generally a positive correlation between the tensile elastic modulus and the indentation elastic modulus, it is presumed that there is also a correlation between the adhesive strength and the elastic modulus in the indentation test.

[0035] (Cover glass) The cover glass 12 is attached to the frame 14 while being curved. In this embodiment, the cover glass 12 is attached to the frame 14 by bending a flat glass sheet by cold forming. That is, the cover glass 12 is attached to the frame 14 in a state where bending stress is applied. The cover glass 12 will be described in more detail below. Note that the cold forming here refers to a method of bending glass into a desired shape without raising the temperature of glass to its softening point.

[0036] (Cover glass shape) Fig. 3 is a top view of the cover glass, and Fig. 4 is a cross-sectional view of the cover glass. In the example of Fig. 3, the cover glass 12 is a curved rectangular flat glass plate. Hereinafter, one side (end face) of the cover glass 12 is referred to as side 12C1, the side opposite to side 12C1 is referred to as side 12C2, the other side of the cover glass 12 is referred to as side 12C3, and the side opposite to side 12C3 is referred to as side 12C4.

[0037] In the example of Fig. 3, the side surfaces 12C1 and 12C2 are the short sides of the rectangle, and the side surfaces 12C3 and 12C4 are the long sides of the rectangle. The cover glass 12 is not limited to a curved rectangular flat glass plate, but may be a curved glass plate of any shape. For example, the cover glass 12 may be a curved polygonal, circular, or elliptical flat glass plate.

[0038] (Cover glass bending) FIG. 3 is a diagram of the cover glass 12 viewed from the normal direction (Z direction) of a position P on the main surface 12B of the cover glass 12, and FIG. 4 shows a cross section S of the cover glass 12 taken along the X direction.

[0039] Here, among the tangential directions of the principal surface 12B of the cover glass 12 at an arbitrary point P of the principal surface 12B, a tangential direction selected so as to satisfy the following condition is defined as the X direction (first direction), among the tangential directions of the principal surface 12B at the point P, a direction perpendicular to the X direction is defined as the Y direction, and a direction perpendicular to the X direction and the Y direction, i.e., a normal direction (thickness direction) to the position P is defined as the Z direction. Here, the X direction refers to, among the tangential directions of the principal surface 12B of the cover glass 12 at an arbitrary point P of the principal surface 12B of the cover glass 12, a direction in which the radius of curvature of a line formed by the intersection of the principal surface 12B with a plane including the tangential direction and the normal direction is smallest.

[0040] Since the cover glass 12 of this embodiment is uniaxially bent, the X-direction can be uniquely defined for any point of the position P. However, as in another example described later, there may be cases where a plurality of curved portions 20 are provided and the bending directions of the respective curved portions 20 intersect. In this case, the X-direction may be defined for each curved portion 20. That is, the direction in which the radius of curvature of the line formed by the intersection of the plane including the tangential direction and the normal direction with the main surface 12B among the tangential directions of the position P on one curved portion 20 is the smallest is defined as the X-direction of that curved portion 20, and the X-direction may be defined similarly for each curved portion 20. In addition, when there are a plurality of tangential directions in which the radius of curvature of the line formed by the intersection of the plane including the tangential direction and the normal direction with the principal surface 12B is the smallest, at least one of the tangential directions may be set to the X direction. Hereinafter, the radius of curvature of the line formed by the intersection of the plane including the X direction and the Z direction with the principal surface 12B will be referred to as the radius of curvature R1.

[0041] It can be said that the cover glass 12 is curved with a radius of curvature R, with the Y direction as the bending axis and the X direction as the direction perpendicular to the bending axis. The radius of curvature R of the cover glass 12 (the radius of curvature of the bend with the Y direction as the bending axis) is preferably 50 mm or more and 10,000 mm or less, more preferably 100 mm or more and 5,000 mm or less, and even more preferably 200 mm or more and 3,000 mm or less. By making the radius of curvature R within this range, peeling from the frame can be suppressed while improving the design. Furthermore, the radius of curvature may be, for example, 2,000 mm or less, 1,750 mm or less, 1,500 mm or less, 1,250 mm or less, or 1,000 mm or less. When the radius of curvature is within this range, peeling from the frame has been easily caused in the past, but by satisfying the formula of the present invention, peeling can be significantly suppressed.

[0042] It is preferable that the cover glass 12 is not bent in any direction other than the bending direction with the Y direction as the bending axis. It is preferable that the cover glass 12 is not bent in any direction with the X direction as the bending axis, in other words, the trajectory along the Y direction on the main surface 12B of the cover glass 12 is preferably linear. It should be noted that not having a bend is not limited to an infinite radius of curvature, and may also include a radius of curvature greater than 10,000 mm. By not bending in any direction other than the Y direction as the bending axis, the cover glass 12 can be flattened and cold forming can be performed appropriately.

[0043] Hereinafter, the portion of the cover glass 12 where a bend is formed with the Y direction as the bending axis will be referred to as the curved portion 20. The curved portion 20 refers to a region of the cover glass 12 that is curved with the Y direction as the bending axis at a constant radius of curvature R. That is, it can be said that the curved portion 20 of the cover glass 12 is curved with the Y direction as the bending axis at a radius of curvature R. In the example of FIG. 4, since the entire cover glass 12 is curved with the same radius of curvature R in the X direction, it can be said that the entire cover glass 12 forms the curved portion 20. Here, the same radius of curvature R does not necessarily mean that the radius of curvature R at each position is exactly the same. For example, if the change in the measured radius of curvature R at each position from one end point to the other end point in the X direction of the region curved with the Y direction as the bending axis on the main surface 12B of the cover glass 12 is 5% or less, that is, if the difference between the maximum value and the minimum value of the radius of curvature R at each position is 5% or less of the maximum value of the radius of curvature R at each position, the region is regarded as a region with the same radius of curvature and is treated as one curved portion 20. The average value of the radius of curvature R at each position of the curved portion 20 may be treated as the radius of curvature R of the curved portion 20.

[0044] Methods for measuring the radius of curvature R of the cover glass 12 include a method of measuring the shape using a contact or non-contact three-dimensional measuring device and determining the radius of curvature R from the shape data, or a method of pressing an R ruler against the cover glass 12 and measuring the radius of curvature R.

[0045] In this embodiment, the curved portion 20 is curved so as to be convex toward the main surface 12A. However, the curved portion 20 is not limited to being curved so as to be convex toward the main surface 12A, and may be curved so as to be convex toward the main surface 12B.

[0046] The arbitrary point P described above is an arbitrary point in the curved portion 20 of the main surface 12B, and may be, for example, the center position of the main surface 12B (for example, the center of gravity position of the cover glass 12) when the central region of the main surface 12A is the curved portion 20. In other words, the X direction and the Y direction may be tangential directions from the center of the main surface 12B, and the Z direction may be a normal direction at the center of the main surface 12B.

[0047] (Length of curved section) The length of the curved portion 20 in the X direction perpendicular to the bending axis is defined as the circumferential length L. The circumferential length L refers to the length of a line that connects an end point (position) on one side of the curved portion 20 in the X direction to an end point (position) on the other side of the curved portion 20 in the X direction and runs along the main surface 12B in the X direction.

[0048] A line running in the X direction on main surface 12B refers to a line that runs along main surface 12B in the X direction without being shifted in the Y direction. In the example of Fig. 3, one end point of curved portion 20 in the X direction is a point on side surface 12C1, and the other end point of curved portion 20 in the X direction is a point on side surface 12C2, so that perimeter L refers to the length of the line running in the X direction on main surface 12B from side surface 12C1 to side surface 12C2.

[0049] The perimeter L is preferably 100 mm or more and 2000 mm or less, more preferably 150 mm or more and 700 mm or less, and even more preferably 200 mm or more and 400 mm or less. Here, the perimeter L is preferably 100 mm or more, more preferably 150 mm or more, and even more preferably 200 mm or more, and preferably 2000 mm or less, more preferably 700 mm or less, and even more preferably 400 mm or less. By setting the perimeter L in this range, it is possible to improve the design while suppressing peeling from the frame. In this embodiment, even if the radius of curvature R is the same, a region where the perimeter L is 5 mm or less (for example, surface irregularities or fine undulations) is not treated as the curved portion 20. In other words, a region where the radius of curvature R is the same and the perimeter L is longer than 5 mm is considered to be the curved portion 20.

[0050] The length of the curved portion 20 in the Y direction, which is the bending axis, is preferably 80 mm or more and 500 mm or less, more preferably 100 mm or more and 400 mm or less, and even more preferably 120 mm or more and 300 mm or less. Here, the length in the Y direction is preferably 80 mm or more, more preferably 100 mm or more, and even more preferably 120 mm or more, and is preferably 500 mm or less, more preferably 400 mm or less, and even more preferably 300 mm or less.

[0051] The length of the curved portion 20 in the Y direction refers to the length of a line that connects an end point (position) on one side of the curved portion 20 in the Y direction to an end point (position) on the other side of the curved portion 20 in the Y direction and runs along the main surface 12B in the Y direction. Note that the line on main surface 12B heading in the Y direction refers to a line that runs along main surface 12B in the Y direction without being shifted in the X direction. In the example of Fig. 3, since the respective points are points on side surfaces 12C3 and 12C4, the length of curved portion 20 in the Y direction refers to the length of the line on main surface 12B heading in the Y direction from side surface 12C3 to side surface 12C4.

[0052] (Cover glass thickness) The thickness t of the cover glass 12 is preferably 0.3 mm or more and 3.0 mm or less, more preferably 0.4 mm or more and 1.5 mm or less, and even more preferably 0.6 mm or more and 1.3 mm or less. Here, the thickness t is preferably 0.3 mm or more, more preferably 0.4 mm or more, and even more preferably 0.6 mm or more, and is preferably 3.0 mm or less, more preferably 1.5 mm or less, and even more preferably 1.3 mm or less. By setting the thickness t in this range, it is possible to improve the design and suppress peeling from the frame. Here, the thickness t refers to the distance in the Z direction from the main surface 12A to the main surface 12B.

[0053] (Young's modulus of cover glass) The Young's modulus E of the cover glass 12 is preferably 60 GPa or more and 90 GPa or less, more preferably 68 GPa or more and 78 GPa or less, and even more preferably 72 GPa or more and 76 GPa or less. Here, the Young's modulus E is preferably 60 GPa or more, more preferably 68 GPa or more, and even more preferably 72 GPa, and is preferably 90 GPa or less, more preferably 78 GPa or less, and even more preferably 76 GPa or less. By having the Young's modulus E in this range, it is possible to improve the design and suppress peeling from the frame.

[0054] (Cover glass material) Any material can be used for the glass of the cover glass 12, but examples of the material that can be used include alkali-free glass, soda-lime glass, soda-lime silicate glass, aluminosilicate glass, borosilicate glass, lithium aluminosilicate glass, and borosilicate glass. Aluminosilicate glass and lithium aluminosilicate glass are preferable for the cover glass 12, because they are susceptible to large stresses due to tempering treatment even when they are thin, and therefore provide high strength glass even when they are thin. Chemical tempering is usually performed by immersing the glass in a molten salt containing an alkali metal.

[0055] The cover glass 12 preferably contains, in mole percent based on oxides, 50-80% SiO2, 0.1-25% Al2O3, 3-30% Li2O+Na2O+K2O, 0-25% MgO, 0-25% CaO, and 0-5% ZrO2, but is not particularly limited thereto. Here, 50-80% refers to 50% or more and 80% or less when the mole percent of the total amount of the cover glass 12 is 100%, and the same applies to other numerical ranges. In addition, Li2O+Na2O+K2O refers to the total content of Li2O, Na2O, and K2O. By making the cover glass 12 have the following composition, the rigidity of the cover glass 12 can be appropriately maintained even when it is curved.

[0056] More specifically, the following glass compositions are preferred for the cover glass 12. For example, "containing 0 to 25% MgO" means that MgO is not essential but may be contained up to 25%.

[0057] Glass (i) is included in soda-lime silicate glasses, glasses (ii) and (iii) are included in aluminosilicate glasses, and glasses (iv) and (v) are included in lithium aluminosilicate glasses.

[0058] (i) A glass having a composition expressed in mole percent of SiO2 of 63 to 73%, Al2O3 of 0.1 to 5.2%, Na2O of 10 to 16%, K2O of 0 to 1.5%, Li2O of 0 to 5.0%, MgO of 5 to 18%, and CaO of 1 to 10%.

[0059] (ii) A glass having a composition, expressed in mole percent, of 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, with the total content of SiO2 and Al2O3 being 65-85%, the total content of Na2O and K2O being 12-25%, and the total content of MgO and CaO being 1-15%.

[0060] (iii) A glass having a composition, expressed in mole percent, of 68-80% SiO2, 4-10% Al2O3, 5-15% Na2O, 0-1% K2O, 0-5.0% Li2O, 4-15% MgO, and 0-1% ZrO2.

[0061] (iv) A glass having a composition, expressed in mole percent, of 67-75% SiO2, 0-4% Al2O3, 7-15% Na2O, 1-9% K2O, 0-5.0% Li2O, 6-14% MgO and 0-1.5% ZrO2, the total content of SiO2 and Al2O3 is 71-75%, the total content of Na2O and K2O is 12-20%, and if CaO is contained, its content is less than 1%.

[0062] (v) A glass having a composition, expressed in mole percent, of 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.

[0063] (adhesion area) Of the entire area of ​​the main surface 12B of the curved portion 20, the area that overlaps with the adhesive layer 16 is referred to as the adhesive area AR, and the area that does not overlap with the adhesive layer 16 is referred to as the area AR0. The adhesive area AR is formed radially outward of the area AR0 when an axis passing through the center position of the curved portion 20 along the Z direction is taken as the axial direction.

[0064] In this embodiment, the entire cover glass 12 constitutes the curved portion 20, and therefore the area of ​​the main surface 12B of the cover glass 12 that overlaps with the adhesive layer 16 becomes the adhesive region AR. Note that the adhesive region AR does not have to be continuous, and multiple discontinuous or spotty adhesive regions AR may be formed.

[0065] In addition, the area of ​​the entire main surface 12B of the curved portion 20 that overlaps with the first adhesive layer having an elastic modulus of 5 MPa or more (the area of ​​the adhesive region AR that overlaps with the first adhesive layer) is defined as the first adhesive region, and the area of ​​the entire main surface 12B of the curved portion 20 that overlaps with the second adhesive layer having an elastic modulus of less than 5 MPa (the area of ​​the adhesive region AR that overlaps with the second adhesive layer) is defined as the second adhesive region.

[0066] In this embodiment, the entire cover glass 12 constitutes the curved portion 20, so that the area of ​​the entire main surface 12B of the cover glass 12 that overlaps with the first adhesive layer is the first adhesive area, and the area of ​​the entire main surface 12B of the cover glass 12 that overlaps with the second adhesive layer is the second adhesive area. In this case, the area A1 of the first adhesive region is 8288 mm 2 The area A2 of the second adhesive region is preferably 20214 mm or less. 2It is preferable that the area A1 of the first adhesive region and the area A2 of the second adhesive region are equal to or less than 80 mm. It is also preferable that the value ((A1+A2) / L) obtained by dividing the sum of the area A1 of the first adhesive region and the area A2 of the second adhesive region (area AR in this embodiment) by the perimeter L is equal to or less than 80 mm. It is also preferable that the area A1 of the first adhesive region is sometimes referred to as the area of ​​the first adhesive layer at the curved portion, and the area A2 of the second adhesive region is sometimes referred to as the area of ​​the second adhesive layer at the curved portion.

[0067] This preferred numerical range is applicable to all cases where the first adhesive region is provided but not the second adhesive region, where the first adhesive region is provided but not the second adhesive region, and where both the first adhesive region and the second adhesive region are provided. In the case where the second adhesive region is not provided but the first adhesive region is provided, the area A1 of the first adhesive region is 350 mm 2 More than 95000mm 2 It is preferable that the length is less than 740 mm. 2 More than 25000mm 2 More preferably, it is 1500 mm or less. 2 More than 8500mm 2 It is more preferable that the area A1 of the first adhesive region is 350 mm or less. 2 It is preferable that the length is 740 mm or more. 2 More preferably, 1500mm or more 2 More preferably, 95,000 mm or more 2 It is preferable that the length is less than 25,000 mm. 2 Less than 8500mm is preferable. 2 The following is even more preferred: In this case, the value (A1 / L) obtained by dividing the area A1 of the first adhesive region by the perimeter L is preferably 50 mm or less, more preferably 35 mm or less, and even more preferably 25 mm or less.

[0068] In the case where the first adhesive region is not provided but the second adhesive region is provided, the area A2 of the second adhesive region is 850 mm 2 More than 230000mm 2It is preferable that the length is less than 1700 mm. 2 More than 60000mm 2 More preferably, it is 3800 mm or less. 2 More than 20000mm 2 It is more preferable that the area A2 of the second adhesive region is 850 mm or less. 2 It is preferable that the thickness is 1700 mm or more. 2 More preferably, 3800mm or more. 2 More preferably, 230,000 mm or more. 2 It is preferable that the length is less than 60,000 mm. 2 Less than 20,000 mm is more preferable. 2 The following is even more preferred: In this case, the value (A2 / L) obtained by dividing the area A2 of the second adhesive region by the perimeter L is preferably 115 mm or less, more preferably 85 mm or less, and even more preferably 50 mm or less.

[0069] In addition, when both the first adhesive region and the second adhesive region are provided, the area A1 of the first adhesive region is 170 mm 2 More than 47000mm 2 It is preferable that the length is less than 370 mm. 2 More than 12000mm 2 More preferably, it is 790 mm or less. 2 More than 4200mm 2 It is more preferable that the area A2 of the second adhesive region is 420 mm or less. 2 More than 110000mm 2 It is preferable that the length is less than 880 mm. 2 More than 29000mm 2 It is more preferable that it is less than 1900 mm. 2 More than 10000mm 2 It is more preferable that the area A1 of the first adhesive region is 170 mm 2 It is preferable that the length is 370 mm or more. 2 More than 790mm is preferable. 2 More preferably, 47,000 mm or more. 2It is preferable that the length is less than 12000 mm. 2 Less than 4200mm is more preferable. 2 More preferably, the area A2 of the second adhesive region is 420 mm 2 It is preferable that the length is 880 mm or more. 2 More than 1900mm is preferable. 2 More preferably, 110,000 mm or more. 2 It is preferable that the length is less than 29,000 mm. 2 Less than 10,000 mm is more preferable. 2 The following is even more preferred: In this case, the sum of the area A1 of the first adhesive region and the area A2 of the second adhesive region (area AR in this embodiment) divided by the circumference L ((A1+A2) / L) is preferably 80 mm or less, more preferably 60 mm or less, and even more preferably 40 mm or less. By setting the area of ​​the first adhesive region and the second adhesive region within this range, it is possible to prevent the area AR0 where the image is displayed from becoming smaller and to prevent peeling from the frame. Note that, for example, a printing layer is formed in the adhesive region AR, and the area AR0 is used as, for example, a display unit.

[0070] (Relationship between cover glass properties) Here, when the cover glass is curved and bonded to the frame, there is a risk that the cover glass will peel off from the frame due to springback, i.e., the force of the cover glass trying to return to a flat plate shape. As a result of intensive research, the inventors have come up with the idea that peeling from the frame can be suppressed by setting the relationships between the properties of the cover glass 12 (in this embodiment, the relationships between the radius of curvature R, the thickness t, the Young's modulus E, the perimeter L, and the areas of the first and second adhesive regions) to appropriate ranges. The relationships between the properties of the cover glass 12 will be described below.

[0071] Hereinafter, the corrected value of the radius of curvature R of the curved portion 20 is referred to as the corrected radius of curvature R'. The corrected radius of curvature R' is expressed by the following formula (1). The corrected radius of curvature R' is the corrected value of the radius of curvature R when flat regions (flat portions) that are not curved and are flat are connected to both sides in the X direction of the curved portion 20 (one side and the other side in the X direction).

[0072]

number

[0073] The length F in formula (1) is the length in the X direction of the flat portion having a shorter length in the X direction among the flat portions adjacent to and connected to both sides in the X direction of the curved portion 20. That is, the length F is the length along the main surface of the flat portion from the end portion on one side in the X direction (the end portion connected to the curved portion 20) of the flat portion having a shorter length in the X direction to the end portion on the other side in the X direction (the end portion not connected to the curved portion 20). In this embodiment, since no flat portion is provided, F is zero, and the corrected radius of curvature R' has the same value as the radius of curvature R. An example in which a flat portion is provided will be described later.

[0074] (When the main surface 12A is convex) A case where the curved portion 20 is curved so as to be convex toward the main surface 12A will be described. In the case where the curved portion 20 is curved so as to be convex toward the main surface 12A, when C2 is a value shown in the following formula (5), if C2 is greater than 0 (C2>0), the curved portion 20 satisfies the following formula (6), and if C2 is equal to or less than 0 (C2≦0), the curved portion 20 satisfies the following formula (7). Note that in formulas (5) to (7), A2 is zero when the second adhesive region is not provided, and A1 is zero when the first adhesive region is not provided.

[0075]

number

[0076]

number

[0077]

number

[0078] We will now explain equations (5) to (7). Figure 5 is an example of a graph for explaining the relationship between the characteristics of the cover glass. In Figure 5, the horizontal axis is the corrected radius of curvature R', and the vertical axis is the value obtained by dividing the area (A1+A2) of the adhesion region AR by the perimeter L, which will hereinafter be referred to as the adhesion width as appropriate.

[0079] The curves in Fig. 5 show the value of the adhesion width at the boundary where the frame peels off for each corrected radius of curvature R' when the thickness t and Young's modulus E are set to predetermined values. In other words, when the thickness t and Young's modulus E are set to predetermined values, peeling of the frame can be suppressed by increasing the adhesion width value beyond that of the curve in Fig. 5. As shown in the curves in Fig. 5, the larger the corrected radius of curvature R' is, the smaller the adhesion width at which peeling can be suppressed can be, and when the corrected radius of curvature R' is equal to or greater than a certain value R'0, the adhesion width at which peeling can be suppressed becomes constant.

[0080] As shown in the graph of FIG. 5, when C2 is 0 or less, the bonding width at which peeling can be suppressed is constant. That is, C2 in formula (5) is an index value for judging whether the bonding width at which peeling can be suppressed is constant, and formula (7) can be said to be a formula that specifies the bonding width at which peeling can be suppressed in the case where the bonding width at which peeling can be suppressed is constant. That is, when C2 is 0 or less, the curved portion 20 can be designed to satisfy formula (7) to suppress peeling. In other words, peeling can be suppressed by setting the corrected radius of curvature R', thickness t, perimeter L, area A1, and area A2 so that C2 is 0 or less, and setting the perimeter L, area A1, and area A2 so that they satisfy formula (7).

[0081] On the other hand, as shown in the graph of FIG. 5, when C2 is greater than 0, the bonding width at which peeling can be suppressed changes depending on the corrected radius of curvature R' and the like. Equation (6) can be said to be an equation that specifies parameters such as the bonding width at which peeling can be suppressed in cases where the bonding width at which peeling can be suppressed changes. That is, when C2 is greater than 0, the curved portion 20 can be designed to satisfy equation (6) to suppress peeling. In other words, peeling can be suppressed by setting the corrected radius of curvature R', thickness t, perimeter L, area A1, and area A2 so that C2 is greater than 0, and setting the corrected radius of curvature R', thickness t, Young's modulus E, perimeter L, area A1, and area A2 so that they satisfy equation (6). Note that Et in equation (6) 2 is a parameter indicating the rigidity of the cover glass 12, and E(t / R') is a parameter indicating the bending stress.

[0082] (When the main surface 12B is convex) A case where the curved portion 20 is curved so as to be convex toward the main surface 12B will be described. In the case where the curved portion 20 is curved so as to be convex toward the main surface 12B, when C1 is a value shown in the following formula (2), if C1 is greater than 0 (C1>0), the curved portion 20 satisfies the following formula (3), and if C1 is equal to or less than 0 (C1≦0), the curved portion 20 satisfies the following formula (4). In formulas (2) to (4), A2 is zero when the second adhesive region is not provided, and A1 is zero when the first adhesive region is not provided.

[0083]

number

[0084]

number

[0085]

number

[0086] As shown in the graph of FIG. 5, when C1 is 0 or less, the bonding width at which peeling can be suppressed is constant. C1 in formula (2) is an index value for judging whether the bonding width at which peeling can be suppressed is constant, and formula (4) can be said to be a formula that specifies the bonding width at which peeling can be suppressed in the case where the bonding width at which peeling can be suppressed is constant. That is, when C1 is 0 or less, the curved portion 20 can be designed to satisfy formula (4) to suppress peeling. In other words, peeling can be suppressed by setting the corrected radius of curvature R', thickness t, perimeter L, area A1, and area A2 so that C1 is 0 or less, and setting the perimeter L, area A1, and area A2 so that they satisfy formula (4).

[0087] On the other hand, as shown in the graph of FIG. 5, when C1 is greater than 0, the adhesive width at which peeling can be suppressed changes depending on the corrected radius of curvature R' and the like. Equation (3) can be said to be an equation that specifies parameters such as the adhesive width at which peeling can be suppressed in cases where the adhesive width at which peeling can be suppressed changes. That is, when C1 is greater than 0, the curved portion 20 can be designed to satisfy Equation (3) to suppress peeling. In other words, peeling can be suppressed by setting the corrected radius of curvature R', thickness t, perimeter L, area A1, and area A2 so that C1 is greater than 0, and setting the corrected radius of curvature R', thickness t, Young's modulus E, perimeter L, area A1, and area A2 so that they satisfy Equation (3).

[0088] When C1 is greater than 0 (C1>0), it is preferable that the curved portion 20 further satisfies the following formula (6): In formula (6), A2 is zero when the second adhesive region is not provided, and A1 is zero when the first adhesive region is not provided. When the curved portion 20 satisfies formula (6), the cover glass 12 is firmly adhered to the frame 14, and peeling is easily prevented even when the cover glass 12 is exposed to high temperatures, thermal cycles, mechanical vibrations and impacts, ultraviolet rays, and the like for a long period of time. Furthermore, by making the curved portion 20 satisfy the formula (6), when the curved portion 20 has a convex curved portion on the main surface 12A side in addition to the convex curved portion on the main surface 12B side, as shown in FIG. 13, peeling can be suppressed even if the adhesive width with the frame is the same in both curved portions, which has the advantage of excellent design.

[0089]

number

[0090] As described above, the glass article 10 according to the present embodiment includes the cover glass 12 having the main surface 12A (first main surface) and the main surface 12B (second main surface), and the frame 14 bonded to the main surface 12B side of the cover glass 12 via the adhesive layer 16. The cover glass 12 is provided with the curved portion 20 having a convex shape toward the main surface 12A, and the adhesive layer 16 includes at least one of a first adhesive layer having an elastic modulus of 5 MPa 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 as shown in formula (1) and C2 is as shown in formula (5), the curved portion 20 satisfies formula (6) when C2>0, and satisfies formula (7) when C2≦0. The glass article 10 according to the present embodiment can suppress peeling from the frame 14 by the curved portion 20 satisfying formula (6) or formula (7).

[0091] As described above, the glass article 10 according to the present embodiment includes the cover glass 12 having the main surface 12A (first main surface) and the main surface 12B (second main surface), and the frame 14 bonded to the main surface 12B side of the cover glass 12 via the adhesive layer 16. The cover glass 12 is provided with the curved portion 20 having a convex shape toward the main surface 12B, and 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 as shown in formula (1) and C1 is as shown in formula (2), the curved portion 20 satisfies formula (3) when C1>0, and satisfies formula (4) when C1≦0. The glass article 10 according to the present embodiment can suppress peeling from the frame 14 by the curved portion 20 satisfying formula (3) or formula (4). Furthermore, it is preferable that the curved portion 20 satisfies the formula (6) when C1>0.

[0092] It is preferable that (A1+A2) / L is 80 mm or less. By making (A1+A2) / L within this range, the area AR0 is prevented from becoming narrower, improving the design and preventing the screen for displaying images from becoming smaller. In addition, by making (A1+A2) / L within this range, the adhesion area can be reduced, making it easier to bond and improving the positional accuracy. In addition, it is more preferable that (A1+A2) / L is 60 mm or less. By making (A1+A2) / L within this range, adhesion defects can be reduced and adhesion can be performed with high reliability, gas escape can be promoted, and the adhesive can be properly spread throughout the entire adhesion area.

[0093] The adhesive layer 16 may include both a first adhesive layer and a second adhesive layer, and the first adhesive layer and the second adhesive layer may be composed of different adhesives. By including both the first adhesive layer and the second adhesive layer, the cover glass 12 and the frame 14 can be appropriately bonded. For example, by providing adhesive layers with different characteristics, such as a second adhesive layer that has low adhesive strength like a double-sided tape but develops adhesive strength immediately after lamination, and a first adhesive layer that has high final adhesive strength like a moisture-curing adhesive but takes time to develop strength, the cover glass 12 and the frame 14 can be bonded with high positional accuracy and sufficient adhesive strength.

[0094] 6 is a diagram showing an example in which both the first adhesive layer and the second adhesive layer are provided. In the case in which both the first adhesive layer and the second adhesive layer are provided, it is preferable to provide the second adhesive layer AR2 radially outward from the first adhesive layer AR1. By providing a second adhesive region with a lower adhesive strength on the outer side, for example, the second adhesive region (e.g., double-sided tape) functions as a bank of adhesive in the first adhesive region, and it is possible to prevent the adhesive in the first adhesive region from protruding outward before hardening.

[0095] In the example of Fig. 6, the outer peripheral edge of the first adhesive layer AR1 and the inner peripheral edge of the second adhesive layer AR2 are separated, and the second adhesive layer AR2 is provided radially outward of the first adhesive layer AR1. However, Fig. 6 is only an example, and when both the first adhesive layer and the second adhesive layer are provided, the positions of the first adhesive layer and the second adhesive layer may be set arbitrarily.

[0096] The thickness t of the cover glass 12 is preferably 0.3 mm or more and 3.0 mm or less. By setting the thickness t in this range, peeling off from the frame 14 can be suitably suppressed.

[0097] The radius of curvature R of the curved portion 20 is preferably 50 mm or more and 10000 mm or less. By setting the radius of curvature R in this range, peeling from the frame 14 can be suitably suppressed while improving the design.

[0098] The Young's modulus E of the cover glass 12 is preferably 60 GPa or more and 90 GPa or less. By setting the Young's modulus E in this range, peeling from the frame 14 can be suitably suppressed.

[0099] The in-vehicle display device 2 according to this embodiment has a display 3 and a glass article 10 provided on a surface (front surface) of the display 3. The in-vehicle display device 2 can prevent the frame 14 from peeling off from the cover glass 12.

[0100] (Other examples) Other examples of the shape of the cover glass 12 will be described below.

[0101] (Example of spline shape) 7 is a schematic diagram of a cover glass according to another example of this embodiment. In the above-mentioned embodiment, the curved portion 20 is described as a portion curved with the same radius of curvature R, but there is also a case where the curved portion 20 is curved in the X direction in a spline curve shape with an inconsistent radius of curvature. In that case, the entire portion curved in the X direction in a spline curve shape is treated as the curved portion 20.

[0102] In the description of the embodiment described above, the region on the main surface 12B that is bent with the Y direction as the bending axis has a change in the measured radius of curvature R of 5% or less at each position from one end point to the other end point in the X direction, and this region has been treated as one curved portion 20 with the same radius of curvature. Meanwhile, in this example, in a region on the main surface 12B bent with the Y direction as the bending axis, in a section of 50 mm or less from one end point on one side in the X direction to the other end point, a region in which the change in the radius of curvature R at each position is higher than 5% is treated as one spline-shaped curved portion 20. Then, as shown in Fig. 7, the spline-shaped curved portion 20 is approximated to a shape bent with a constant radius of curvature, and the radius of curvature when approximated to a shape bent with a constant radius of curvature is treated as the radius of curvature R of the curved portion 20. Specifically, one end point in the X direction of main surface 12B of spline-shaped curved portion 20 is defined as end point 20J, the other end point is defined as end point 20K, and a plane connecting end point 20J and end point 20K and extending along the X and Y directions (i.e., the XY plane passing through end points 20J and 20K) is defined as plane α. If a plane obtained by translating plane α in the Z direction so as to be tangent to main surface 12B is defined as plane β, the radius of curvature of arc 20R that passes through end points 20J and 20K and is tangent to plane β is defined as the radius of curvature R of curved portion 20.

[0103] (Example with flat area) 8 and 9 are schematic diagrams of a cover glass according to another example of this embodiment. A flat portion 22 may be connected to the curved portion 20 in the X direction. The flat portion 22 is connected to the curved portion 20 so that the main surface 12B is continuous (not discontinuous) with the curved portion 20. FIG. 8 shows an example in which 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 of the entire area of ​​the cover glass 12 that is connected to the end of the curved portion 20 in the X direction. The flat portion 22 being flat is not limited to having an infinite radius of curvature, and may also include having a radius of curvature greater than 10,000 mm.

[0104] When the flat portion 22 is connected to the curved portion 20, the curved portion 20 and the flat portion 22 are treated as one curved portion 20a in application of formulas (1) to (7). For example, when the flat portion 22 is provided on one side of the curved portion 20 in the X direction and the flat portion 22 is not provided on the other side in the X direction as shown in Fig. 8, the length in the X direction which is the bending direction of the curved portion 20a (the total value of the length in the X direction of the curved portion 20 and the length F of the flat portion 22) is treated as the circumferential length L.

[0105] Also, the area of ​​the region of the main surface 12B of the curved portion 20a overlapping with the first adhesive layer (the sum of the area of ​​the region of the main surface 12B of the curved portion 20 overlapping with the first adhesive layer and the area of ​​the region of the main surface 12B of the flat portion 22 overlapping with the first adhesive layer) is treated as area A1. Also, the area of ​​the region of the main surface 12B of the curved portion 20a overlapping with the second adhesive layer (the sum of the area of ​​the region of the main surface 12B of the curved portion 20 overlapping with the second adhesive layer and the area of ​​the region of the main surface 12B of the flat portion 22 overlapping with the second adhesive layer) is treated as area A2. However, when the flat portion 22 is provided on one side of the curved portion 20 in the X direction and the flat portion 22 is not provided on the other side in the X direction, the length F in formula (1) is treated as zero, similarly to the case where there is no flat portion 22. In other words, when the curved portion 20 is provided on only one side, the corrected radius of curvature R' has the same value as the radius of curvature R.

[0106] As shown in FIG. 9, the flat portion 22 may be provided so as to connect to both sides of the curved portion 20 in the X direction (one side and the other side in the X direction).

[0107] 9, when the flat portion 22 on one side of the curved portion 20 in the X direction and the flat portion 22 on the other side have different lengths along the main surface 12B, the curved portion 20 and the flat portion 22 having the shorter length along the main surface 12B are treated as one 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 formula (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 circumferential length L. In addition, the area of ​​the region of the main surface 12B of the curved portion 20a that overlaps with the first adhesive layer (the sum of the area of ​​the region of the main surface 12B of the curved portion 20 that overlaps with the first adhesive layer and the area of ​​the region of the main surface 12B of the shorter flat portion 22 that overlaps with the first adhesive layer) is treated as area A1. Also, the area of ​​the region overlapping with the second adhesive layer in the main surface 12B of the curved portion 20a (the total value of the area of ​​the region overlapping with the second adhesive layer in the main surface 12B of the curved portion 20 and the area of ​​the region overlapping with the second adhesive layer in the main surface 12B of the shorter flat portion 22) is treated as the area A2. When the lengths along the main surface 12B of the flat portion 22 on one side and the flat portion 22 on the other side in the X direction of the curved portion 20 are the same, the curved portion 20 and either one of the flat portions 22 are treated as one curved portion 20a.

[0108] (Example of multiple curved sections) 10 and 11 are schematic diagrams of a cover glass according to another example of this embodiment. A plurality of curved portions 20 may be provided, in other words, a plurality of curved portions 20 having different radii of curvature R may be formed on the cover glass 12. In this case, each curved portion 20 is bent with the same direction, that is, the Y direction, as the bending axis.

[0109] The presence of a plurality of curved portions 20 can be determined as follows. That is, in a region on the main surface 12B bent about the Y direction as a bending axis, where the change in the radius of curvature R at each position in a section longer than 50 mm from an end point on one side in the X direction to an end point on the other side is greater than 5%, it is determined that a plurality of curved portions 20 with different radii of curvature R are formed. That is, in a region on the main surface 12B bent about the Y direction as a bending axis, if the change in the radius of curvature R is 5% or less in a section 50 mm or less from an end point on one side in the X direction to an end point on the other side, but the change in the radius of curvature R exceeds 5% in a section longer than 50 mm from an end point on one side to an end point on the other side, it is determined that a plurality of curved portions are formed, rather than a single spline-shaped curved portion.

[0110] 10, among the regions on the main surface 12B bent with the Y direction as the bending axis, a region in which the change in the radius of curvature R at each position in the section from one end point 20L on one side to the other end point 20M in the X direction of the region is 5% or less is defined as one curved portion 20A with the same radius of curvature R. The curved portion 20A is a region from the one end point 20L to a position 20N where the change in the radius of curvature R is greater than 5%. Then, a region in which the change in the radius of curvature R at each position in the section from the position 20N to the other end point 20M is 5% or less is defined as another curved portion 20B.

[0111] 10, the change in the radius of curvature is 5% or less in the section from position 20N to end point 20M, so the region from position 20N to end point 20M is treated as curved portion 20B. However, for example, if there is a position between position 20N and end point 20M where the change in the radius of curvature R is greater than 5%, the region from position 20N to the position where the change in the radius of curvature R is greater than 5% becomes one curved portion 20B. In this case, there will be three or more curved portions 20.

[0112] In this way, when a plurality of curved portions 20 are formed, formulas (1) to (7) are applied to each curved portion 20. That is, when each curved portion 20 is convex toward the main surface 12A side, formula (6) or formula (7) is satisfied, and when each curved portion 20 is convex toward the main surface 12B side, formula (3) or formula (4) is satisfied. FIG. 10 shows an example in which a curved portion 20A having a curvature radius R1 and a curved portion 20B having a curvature radius R2 are formed. In the example of FIG. 10, both the curved portions 20A and 20B are convex toward the main surface 12A side, but this is not limited thereto, and both the curved portions 20A and 20B may be convex toward the main surface 12B side. In addition, the number of curved portions 20 is not limited to two, and may be three or more.

[0113] 11 shows an example in which a flat portion 22 is connected to a plurality of bending portions 20. When a flat portion 22 is connected to a plurality of bending portions 20, in application of formulas (1) to (7), one bending portion 20 and the flat portion 22 connected to that bending portion 20 are treated as one bending portion 20a.

[0114] In the example of FIG. 11, a long flat portion 22 is connected to one side of the curved portion 20A in the X direction, a short flat portion 22 is connected to the other side of the curved portion 20A in the X direction, and a curved portion 20B is connected to the short flat portion 22 on the opposite side of the curved portion 20A. In this case, the curved portion 20A and the short flat portion 22 are treated as one curved portion 20a, and the curved portion 20B and the short flat portion 22 are treated as another curved portion 20a. The calculation method of the length F, the perimeter L, the area A1, and the area A2 for the curved portion 20a is the same as that when the flat portion 22 is connected to one curved portion 20, so the explanation is omitted. In the example of FIG. 11, the flat portion 22 is connected to only one side of the curved portion 20A, so the length F in the equation (1) for the curved portion 20A is treated as zero.

[0115] 12 and 13 are schematic diagrams of a cover glass according to another example of this embodiment. In the above description, the curved portions 20 are convex in the same direction, but they may be convex in different directions. For example, as shown in FIG. 12, the curved portion 20A may be convex on the main surface 12A side, and the curved portion 20B may be convex on the main surface 12B side.

[0116] In the example of FIG. 13, the long flat portion 22 is connected to one side of the curved portion 20A in the X direction, the short flat portion 22 is connected to the other side of the curved portion 20A in the X direction, and the curved portion 20B is connected to the short flat portion 22 on the opposite side to the curved portion 20A. In this case, the curved portion 20A and the short flat portion 22 are treated as one curved portion 20a, and the curved portion 20B and the short flat portion 22 are treated as another curved portion 20. The calculation method of the length F, the perimeter L, the area A1, and the area A2 for the curved portion 20a is the same as that in the case where the flat portion 22 is connected to one curved portion 20, so the explanation is omitted. In addition, the formulas (1) to (7) are applied to each curved portion. That is, the curved portion 20A is convex toward the main surface 12A side, so that the formula (6) or the formula (7) is satisfied, and the curved portion 20B is convex toward the main surface 12B side, so that the formula (3) or the formula (4) is satisfied.

[0117] 14 to 17 are schematic diagrams of cover glasses according to other examples of this embodiment. In the above-described embodiment, a rectangular glass plate is bent in the X direction to form the cover glass 12, so the length of the cover glass 12 in the X direction is constant for each position. However, depending on the shape, the length of the cover glass 12 in the X direction may differ from position to position. The perimeter L in such a case will be described below.

[0118] As described above, the perimeter L refers to the length of a line that connects from the position on the most one side in the X direction with respect to the bending axis YA along the direction Y of the curved portion 20 to the position on the most other side in the X direction with respect to the bending axis YA of the curved portion 20, and runs along the X direction on the main surface 12B. Therefore, for example, as shown in Fig. 14, when a trapezoidal glass plate is bent with the Y direction as the bending axis to form the cover glass 12, both end points of the side surface 12C3 that is the long side of the trapezoid are the position 20C on the most one side and the position 20D on the most other side in the X direction with respect to the bending axis YA of the curved portion 20, and the length of the line that connects the positions 20C and 20D and runs along the X direction on the main surface 12B is the perimeter L.

[0119] In the above description, the X direction perpendicular to the bending axis is along the side surfaces 12C3 and 12C4, which are the horizontal sides of the flat cover glass 12 before bending, but the present invention is not limited thereto. The X direction perpendicular to the bending axis may be shifted (intersected) with respect to the sides of the flat cover glass 12 before bending. FIG. 15 shows an example in which the X direction intersects with the side surfaces 12C3 and 12C4 of the flat cover glass 12 before bending. In the example of FIG. 15, one end point of the side surface 12C3, which is the long side of the trapezoid, is the position 20C, and the other end point of the side surface 12C4, which is the short side of the trapezoid, is the position 20D. In the example of FIG. 15, the positions of the position 20C and the position 20D are not aligned in the Y direction, so the length of the line that connects the position 20D', which is the position 20D shifted in the Y direction, and the position 20C along the main surface 12B in the X direction, is defined as the perimeter L. 15, the length of the curve that connects position 20C and position 20D' and has a radius of curvature R is the perimeter L. Position 20D' is a position obtained by shifting position 20D in the Y direction so that its position in the Y direction is aligned with the position of position 20C in the Y direction. In this way, when positions 20C and 20D are not aligned in the Y direction, the length of the line that runs in the X direction along main surface 12B from position 20C, where the positions in the Y direction are aligned, to position 20D' is defined as the perimeter L.

[0120] Fig. 16 shows an example of a case where a polygonal glass plate is curved around a line segment YA along direction Y as a bending axis to form cover glass 12. In the example of Fig. 16, the positions in the Y direction of positions 20C and 20D, which are the points on one side and the other side in the X direction with respect to the bending axis YA along direction Y of curved portion 20, are not aligned, so the length of the line connecting positions 20D' and 20C and running in the X direction on the surface along main surface 12B is the perimeter L.

[0121] Fig. 17 shows an example of a case where a glass plate having a curved periphery is curved around a line segment YA along direction Y as a bending axis to form cover glass 12. In the example of Fig. 17, the positions in the Y direction of positions 20C and 20D, which are the points on one side and the other side in the X direction with respect to the bending axis YA along direction Y of curved portion 20, are not aligned, so the length of the line that connects positions 20D' and 20C and runs in the X direction on the surface along main surface 12B is the perimeter L.

[0122] 18 to 20 are schematic diagrams of cover glass according to another example of this embodiment. In the above description, the multiple curved portions 20 are bent in the same direction with the Y direction as the bending axis, but the bending axes of the multiple curved portions 20 may be different. In this case, the bending axes of the respective curved portions 20 do not intersect on the main surface 12A of the cover glass 12, but intersect at a point where the bending axes of the respective curved portions 20 are extended outward from the main surface 12A. Even if the bending axes of the curved portions 20 are different in direction, the bending axes do not intersect on the main surface 12A, so that the cover glass 12 can be flattened and appropriately cold-formed.

[0123] 18 and 19 show examples of schematic diagrams of a cover glass 12 in which the directions of the bending axes of multiple curved portions 20 are different. In the example of Fig. 18, a curved portion 20A is connected to one side of a flat portion 22 in the X direction, and a curved portion 20B is connected to the other side of the flat portion 22 in the X direction.

[0124] The curved portion 20A is bent about the bending axis YA from the side surface 12C1, which is the end edge on one side in the X direction, to the end edge 20P on the other side. That is, the curved portion 20A is a region bent about the bending axis YA so 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 5% or less. The curved portion 20B is bent about the bending axis YB from the end edge 20Q on one side in the X direction to the side surface 12C2, which is the end edge on the other side. That is, the curved portion 20B is a region bent about the bending axis YB so 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 5% or less. The flat portion 22 is a flat region from the end edge 20P to the end edge 20Q in the X direction.

[0125] 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 cover glass 12, but intersect at a point where the bending axes YA and YB are extended outward from the main surface 12A. For convenience of explanation, Fig. 18 is shown with the Y direction as the bending axis, i.e., the bending axes YA and YB are in the same direction, but in reality, the bending axes YA and YB of the curved portions 20A and 20B extend in different directions.

[0126] When a flat portion 22 is connected to multiple curved portions 20 having different bending axis directions, for the purpose of applying equations (1) to (7), one curved portion 20 and the flat portion 22 connected to that curved portion 20 are treated as one curved portion 20a.

[0127] In the example of FIG. 19, the flat portion 22 is connected to the other side in the X direction of the bending portion 20A, and the flat portion 22 is connected to one side in the X direction of the bending portion 20B. In this case, the bending portion 20A and the flat portion 22 are treated as one bending portion 20a, and the bending portion 20B and the flat portion 22 are treated as another bending portion 20a. The method of calculating the length F, area A1, and area A2 for the bending portion 20a is the same as when the flat portion 22 is connected to one bending portion 20, so the explanation is omitted. In the example of FIG. 19, the flat portion 22 is connected to only one side of the bending portions 20A and 20B, so the length F in the formula (1) for the bending portions 20A and 20B is treated as zero.

[0128] A method for calculating the circumferential length L of a plurality of curved portions 20 having different bending axis directions will be described with reference to Fig. 20. For ease of explanation, Fig. 20 illustrates an extracted curved portion 20a including curved portion 20A and flat portion 22. In the example of Fig. 20, the end point of side surface 12C1 closest to one side in the X direction is position 20C of curved portion 20a, and the end point of end edge 20P' closest to the other side in the X direction is position 20D of curved portion 20a.

[0129] In the example of Fig. 20, since the positions 20C and 20D are not aligned in the Y direction, the length of a line connecting position 20D', which is a position 20D shifted in the Y direction, and position 20C, and running along the main surface 12B in the X direction, is taken as the perimeter L of curved portion 20a. That is, in the example of Fig. 20, the length of a curve connecting position 20C and position 20D', with a radius of curvature R, is taken as the perimeter L. Note that the perimeter L can be calculated similarly for curved portion 20a including curved portion 20B and flat portion 22, but a description thereof will be omitted. EXAMPLES

[0130] Next, examples will be described. Note that the embodiment may be changed as long as the effects of the invention are achieved. In each example, either an actual test or a simulation test was performed. In Tables 1 to 10 described later, if the actual test column has a description "Yes", an actual test was performed, and if the column is blank, a simulation was performed. In addition, among the plots in Figures 21 to 42 described later, the results surrounded by circles are the results of the actual test.

[0131] (simulation) The simulation used impact and collision analysis software using the finite element method (PAM-CRASH, manufactured by Japan ESI Co., Ltd.). The simulation used COS3D (Material Type 305), which allows the adhesive fracture energy to be set for the adhesive layer, and the adhesive fracture energy EFRSn was set to match the actual test. In the simulation, first, bending elastic energy (accumulated as stress in the glass) was given to the glass plate. Next, a frame is attached to the bent glass plate via an adhesive layer. The adhesive layer and frame are deformed by the elastic energy of the glass, and elements in the adhesive layer whose adhesive energy exceeds the adhesive fracture energy disappear, making it possible to simulate the phenomenon of the glass peeling off from the frame. It has been confirmed that there is no discrepancy between the simulation results and the results of actual tests. The adhesive fracture energy of the weak adhesive layer in the simulation was set based on the results of actual tests of weak adhesive layers.

[0132] (Simulation conditions) A model corresponding to the actual test was created with the physical properties below and the conditions described in each example, and it was judged whether peeling occurred. If no peeling occurred, it was rated as A (pasting possible), and if peeling occurred within 2 msec, it was rated as B (pasting not possible). ·Glass plate Young's modulus: 70 GPa (G = 29.17, K = 38.89), 74 GPa (G = 30.08, K = 45.68), 77 GPa (G = 31.56, K = 45.83) ·Frame Young's modulus: 206 GPa (G = 79.231, K = 171.667) Here, G is the shear modulus and K is the bulk modulus.

[0133] (Actual test) In the actual test, an aluminosilicate glass plate (product name: Dragontrail) manufactured by AGC was used as the glass plate. This glass plate was bent laterally (X direction) so that the side not bonded to the frame (first main surface side) was convex or the side bonded to the frame (second main surface side) was convex to form a cover glass curved in the X direction, and the edge on the peripheral side was bonded to a frame-shaped frame via an adhesive layer so that it did not protrude from the frame. The frame was made of rolled steel SS400, and the adhesive layer used was either Threebond's 1539, which is a strong adhesive layer (first adhesive layer), or 3M's VHX-1701-04, which is a weak adhesive layer (second adhesive layer). In the actual test, a visual inspection was conducted after 200 hours to evaluate whether the cover glass had peeled off from the frame. If it had not peeled off after 200 hours, it was rated as A (sufficient for lamination), and if it had peeled off after 200 hours, it was rated as B (not suitable for lamination).

[0134] [Table 1]

[0135] (Example 1, Example 2) Table 1 shows the properties of the cover glasses of Examples 1 and 2. Fig. 21 is a graph showing the evaluation results of each of the cover glasses of Examples 1 and 2. In Examples 1 and 2, a rectangular glass plate was prepared with a thickness t of 1.1 mm, a vertical (Y direction) length of 150 mm, and a horizontal (X direction) length of 250 mm. The Young's modulus of the glass plate was 74 GPa, and an aluminosilicate glass plate manufactured by AGC (product name: Dragon Trail) was used. In Examples 1 and 2, the cover glass was bent in the horizontal direction (X direction) so that the side to be bonded to the frame (the second main surface side) was convex, and the entire cover glass was curved, so that no flat portion was formed, and the entire cover glass became a single curved portion. The adhesive layer was assumed to be an adhesive (Adhesive 1539 manufactured by ThreeBond) equivalent to the first adhesive layer. The frame was assumed to be made of rolled steel SS400. In Examples 1 and 2, multiple samples with different curvature radii R, areas A1, and perimeters L as shown in Table 1 were prepared.

[0136] Fig. 21 is a graph plotting the relationship between the radius of curvature R and the value (bonding width) obtained by dividing the area of ​​the bonding region (here, the area A1 of the first bonding region) by the perimeter L for each sample in Example 1 and Example 2. The solid line in Fig. 21 is a boundary line indicating whether formula (3) or formula (4) is satisfied, and it can be said that samples whose values ​​on the vertical axis are equal to or greater than the solid line satisfy formula (3) or formula (4). The dotted line in FIG. 21 is the boundary line that satisfies formula (6), and samples whose values ​​on the vertical axis are equal to or greater than the dotted line satisfy formula (6).

[0137] It is seen that Example 1, which is a comparative example, does not satisfy formula (3) or formula (4) and the cover glass peels off from the frame, while Example 2, which is an embodiment, satisfies formula (3) or formula (4) and can prevent the cover glass from peeling off from the frame.

[0138] [Table 2]

[0139] (Example 3, Example 4) Table 2 shows the characteristics of the cover glasses of Examples 3 and 4. Fig. 22 is a graph showing the evaluation results of each of the cover glasses of Examples 3 and 4. In Examples 3 and 4, a part of the cover glass was curved to form flat parts on both sides of the curved part. In Examples 3 and 4, a plurality of samples were prepared with different curvature radii R, areas A1, and perimeter lengths L as shown in Table 1. The other points were the same as in Examples 1 and 2. 22, it is seen that Example 3, which is a comparative example, does not satisfy formula (3) or formula (4), and the cover glass peels off from the frame, while Example 4, which is an embodiment, satisfies formula (3) or formula (4), and can suppress the cover glass from peeling off from the frame. Also, some samples in Example 4 further satisfied formula (6).

[0140] [Table 3]

[0141] (Example 5, Example 6) Table 3 shows the properties of the cover glasses of Examples 5 to 10. Fig. 23 is a graph showing the evaluation results of each of the cover glasses of Examples 5 and 6. Examples 5 and 6 were similar to Examples 1 and 2, except that the thickness of the cover glass was 0.7 mm, and the radius of curvature R, area A1, and perimeter L were as shown in Table 3. 23, it is found that Comparative Example 5 does not satisfy formula (3) or formula (4) and the cover glass peels off from the frame, while Example 6 satisfies formula (3) or formula (4) and can suppress the cover glass from peeling off from the frame. Also, some samples of Example 6 further satisfied formula (6).

[0142] (Example 7, Example 8) FIG. 24 is a graph showing the evaluation results of each of the cover glasses of Examples 7 and 8. In Examples 7 and 8, a portion of the cover glass was curved to form flat portions on both sides of the curved portion, and the radius of curvature R, area A1, and perimeter L were the same as in Examples 5 and 6, except that the radius of curvature R, area A1, and perimeter L were as shown in Table 3. As shown in Table 3 and FIG. 24, it is seen that Example 7, which is a comparative example, does not satisfy formula (3) or formula (4) and the cover glass peels off from the frame, while Example 8, which is an embodiment, satisfies formula (3) or formula (4) and can prevent the cover glass from peeling off from the frame.

[0143] (Example 9, Example 10) FIG. 25 is a graph showing the evaluation results of each of the cover glasses of Examples 9 and 10. Examples 9 and 10 were the same as Examples 1 and 2, except that the thickness of the cover glass was 0.5 mm, and the radius of curvature R, area A1, and perimeter L were as shown in Table 3. As shown in Table 3 and FIG. 25, it is seen that Example 9, which is a comparative example, does not satisfy formula (3) or formula (4) and the cover glass peels off from the frame, while Example 10, which is an embodiment, satisfies formula (3) or formula (4) and can prevent the cover glass from peeling off from the frame.

[0144] [Table 4]

[0145] (Example 11, Example 12) Table 4 is a table showing the properties of the cover glasses of Examples 11 and 12. Fig. 26 is a graph showing the evaluation results of each of the cover glasses of Examples 11 and 12. In Examples 11 and 12, an adhesive corresponding to the second adhesive layer (double-sided tape VHX-1701-04 manufactured by 3M) was used as the adhesive layer, and the radius of curvature R, area A2, and circumference L were as shown in Table 4, but the other factors were the same as in Examples 1 and 2. As shown in Table 4 and FIG. 26, it is seen that Example 12, which is a comparative example, does not satisfy formula (3) or formula (4) and the cover glass peels off from the frame, while Example 11, which is an embodiment, satisfies formula (3) or formula (4) and can prevent the cover glass from peeling off from the frame.

[0146] [Table 5]

[0147] (Example 13, Example 14) Table 5 is a table showing the properties of the cover glasses of Examples 13 and 14. Fig. 27 is a graph showing the evaluation results of each of the cover glasses of Examples 13 and 14. In Examples 13 and 14, a portion of the cover glass was curved to form flat portions on both sides of the curved portion, and the radius of curvature R, area A2, and perimeter L were as shown in Table 5, but the other examples were the same as Examples 11 and 12. As shown in Table 5 and FIG. 27, it is seen that Example 13, which is a comparative example, does not satisfy formula (3) or formula (4) and the cover glass peels off from the frame, while Example 14, which is an embodiment, satisfies formula (3) or formula (4) and can prevent the cover glass from peeling off from the frame. In addition, some samples in Example 14 further satisfied formula (6).

[0148] [Table 6]

[0149] (Example 15, Example 16) Table 6 shows the properties of the cover glasses of Examples 15 to 20 and Examples 41 to 44. Fig. 28 is a graph showing the evaluation results of the cover glasses of Examples 15 and 16. Examples 15 and 16 were the same as Examples 11 and 12, except that the thickness of the cover glass was 0.7 mm, and the radius of curvature R, area A2, and perimeter L were as shown in Table 6. As shown in Table 6 and FIG. 28, it is seen that Example 15, which is a comparative example, does not satisfy formula (3) or formula (4) and the cover glass peels off from the frame, while Example 16, which is an embodiment, satisfies formula (3) or formula (4) and can prevent the cover glass from peeling off from the frame. In addition, some samples in Example 16 further satisfied formula (6).

[0150] (Example 17, Example 18) FIG. 29 is a graph showing the evaluation results of the cover glasses of Examples 17 and 18. In Examples 17 and 18, a portion of the cover glass was curved to form flat portions on both sides of the curved portion, and the radius of curvature R, area A2, and perimeter L were as shown in Table 6, but the other examples were the same as Examples 15 and 16. As shown in Table 6 and FIG. 29, it is seen that Example 17, which is a comparative example, does not satisfy formula (3) or formula (4) and the cover glass peels off from the frame, while Example 18, which is an embodiment, satisfies formula (3) or formula (4) and can prevent the cover glass from peeling off from the frame.

[0151] (Example 19, Example 20) FIG. 30 is a graph showing the evaluation results of each of the cover glasses of Examples 19 and 20. Examples 19 and 20 were similar to Examples 11 and 12, except that the thickness of the cover glass was 0.5 mm and the radius of curvature R, area A2, and perimeter L were as shown in Table 6. As shown in Table 6 and FIG. 30, it is seen that Example 19, which is a comparative example, does not satisfy formula (3) or formula (4) and the cover glass peels off from the frame, while Example 20, which is an embodiment, satisfies formula (3) or formula (4) and can prevent the cover glass from peeling off from the frame. In addition, some samples in Example 20 further satisfied formula (6).

[0152] (Examples 41-44) 41 and 42 are graphs showing the evaluation results of each of the cover glasses of Examples 41 to 44. Examples 41 to 44 were similar to Examples 11 and 12 except that the Young's modulus of the glass plate was 70 GPa or 77 GPa, and the radius of curvature R, area A2, and perimeter L were as shown in Table 6. As shown in Table 6 and Figures 41 and 42, it is found that Comparative Examples 42 and 44 do not satisfy Formula (3) or Formula (4) and the cover glass peels off from the frame, while Examples 41 and 43, which are embodiments, satisfy Formula (3) or Formula (4) and can prevent the cover glass from peeling off from the frame.

[0153] [Table 7]

[0154] (Example 21, Example 22) Table 7 shows the properties of the cover glasses of Examples 21 to 24. Fig. 31 is a graph showing the evaluation results of each of the cover glasses of Examples 21 and 22. In Examples 21 and 22, the sample was bent laterally (in the X direction) so as to be convex toward the side not bonded to the frame (the first main surface side), and the radius of curvature R, area A2, and perimeter L were the same as in Examples 1 and 2, except that the sample was bent laterally (in the X direction) so as to be convex toward the side not bonded to the frame (the first main surface side), and the radius of curvature R, area A2, and perimeter L were as shown in Table 7. As shown in Table 7 and FIG. 31, it is seen that Example 21, which is a comparative example, does not satisfy formula (6) or formula (7) and the cover glass peels off from the frame, while Example 22, which is an embodiment, satisfies formula (6) or formula (7) and can prevent the cover glass from peeling off from the frame.

[0155] (Example 23, Example 24) FIG. 32 is a graph showing the evaluation results of each of the cover glasses of Examples 23 and 24. In Examples 23 and 24, an adhesive corresponding to the second adhesive layer (double-sided tape VHX-1701-04 manufactured by 3M) was used as the adhesive layer, and the radius of curvature R, area A2, and circumference L were as shown in Table 7, but the other factors were the same as in Examples 21 and 22. As shown in Table 7 and FIG. 32, it is seen that Example 24, which is a comparative example, does not satisfy formula (6) or formula (7) and the cover glass peels off from the frame, while Example 23, which is an embodiment, satisfies formula (6) or formula (7) and can prevent the cover glass from peeling off from the frame.

[0156] [Table 8]

[0157] (Example 25, Example 26) Table 8 is a table showing the properties of the cover glasses of Examples 25 to 28. Fig. 33 is a graph showing the evaluation results of each of the cover glasses of Examples 25 and 26. In Examples 25 and 26, a portion of the cover glass was curved to form flat portions on both sides of the curved portion, and the radius of curvature R, area A2, and perimeter L were as shown in Table 7, but the other examples were the same as Examples 23 and 24. As shown in Table 8 and FIG. 33, it is seen that Example 25, which is a comparative example, does not satisfy formula (6) or formula (7) and the cover glass peels off from the frame, while Example 26, which is an embodiment, satisfies formula (6) or formula (7) and can prevent the cover glass from peeling off from the frame.

[0158] (Example 27, Example 28) FIG. 34 is a graph showing the evaluation results of the cover glasses of Examples 27 and 28. In Examples 27 and 28, a portion of the cover glass was curved to form flat portions on both sides of the curved portion, and the radius of curvature R, area A2, and perimeter L were as shown in Table 7, but the other examples were the same as Examples 21 and 22. As shown in Table 8 and FIG. 34, it is seen that Example 27, which is a comparative example, does not satisfy formula (6) or formula (7) and the cover glass peels off from the frame, while Example 28, which is an embodiment, satisfies formula (6) or formula (7) and can prevent the cover glass from peeling off from the frame.

[0159] [Table 9]

[0160] (Example 29, Example 30) Table 9 shows the properties of the cover glasses of Examples 29 to 36. Fig. 35 is a graph showing the evaluation results of the cover glasses of Examples 29 and 30. Examples 29 and 30 were similar to Examples 23 and 24, except that the thickness of the cover glass was 0.7 mm and the radius of curvature R, area A2, and perimeter L were as shown in Table 9. As shown in Table 9 and FIG. 35, it is seen that Example 29, which is a comparative example, does not satisfy formula (6) or formula (7) and the cover glass peels off from the frame, while Example 30, which is an embodiment, satisfies formula (6) or formula (7) and can prevent the cover glass from peeling off from the frame.

[0161] (Example 31, Example 32) FIG. 36 is a graph showing the evaluation results of the cover glasses of Examples 31 and 32. In Examples 31 and 32, a portion of the cover glass was curved to form flat portions on both sides of the curved portion, and the radius of curvature R, area A2, and perimeter L were the same as in Examples 29 and 30, except that the radius of curvature R, area A2, and perimeter L were as shown in Table 9. As shown in Table 9 and FIG. 36, it is seen that Example 31, which is a comparative example, does not satisfy formula (6) or formula (7) and the cover glass peels off from the frame, while Example 32, which is an embodiment, satisfies formula (6) or formula (7) and can prevent the cover glass from peeling off from the frame.

[0162] (Example 33, Example 34) FIG. 37 is a graph showing the evaluation results of the cover glasses of Examples 33 and 34. Examples 33 and 34 were the same as Examples 21 and 22, except that the thickness of the cover glass was 0.7 mm, and the radius of curvature R, area A2, and perimeter L were as shown in Table 9. As shown in Table 9 and FIG. 37, it is seen that Example 33, which is a comparative example, does not satisfy formula (6) or formula (7) and the cover glass peels off from the frame, while Example 34, which is an embodiment, satisfies formula (6) or formula (7) and can prevent the cover glass from peeling off from the frame.

[0163] (Example 35, Example 36) FIG. 38 is a graph showing the evaluation results of the cover glasses of Examples 35 and 36. In Examples 35 and 36, a portion of the cover glass was curved to form flat portions on both sides of the curved portion, and the radius of curvature R, area A2, and perimeter L were as shown in Table 9, but the other examples were the same as Examples 33 and 34. As shown in Table 9 and FIG. 38, it is seen that Example 35, which is a comparative example, does not satisfy formula (6) or formula (7) and the cover glass peels off from the frame, while Example 36, which is an embodiment, satisfies formula (6) or formula (7) and can prevent the cover glass from peeling off from the frame.

[0164] [Table 10]

[0165] (Example 37, Example 38) Table 10 shows the properties of the cover glasses of Examples 37 to 40. Fig. 39 is a graph showing the evaluation results of the cover glasses of Examples 37 and 38. Examples 37 and 38 were the same as Examples 23 and 24, except that the thickness of the cover glass was 0.5 mm and the radius of curvature R, area A2, and perimeter L were as shown in Table 9. As shown in Table 10 and FIG. 39, it is seen that Example 37, which is a comparative example, does not satisfy formula (6) or formula (7) and the cover glass peels off from the frame, while Example 38, which is an embodiment, satisfies formula (6) or formula (7) and can prevent the cover glass from peeling off from the frame.

[0166] (Example 39, Example 40) FIG. 40 is a graph showing the evaluation results of the cover glasses of Examples 39 and 40. Examples 39 and 40 were similar to Examples 21 and 22, except that the thickness of the cover glass was 0.5 mm and the radius of curvature R, area A2, and perimeter L were as shown in Table 9. As shown in Table 10 and FIG. 40, it is seen that Example 39, which is a comparative example, does not satisfy formula (6) or formula (7) and the cover glass peels off from the frame, while Example 40, which is an embodiment, satisfies formula (6) or formula (7) and can prevent the cover glass from peeling off from the frame.

[0167] Although the embodiment of the present invention has been described above, the embodiment is not limited to the contents of this embodiment. The above-mentioned components include those that a person skilled in the art can easily imagine, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the above-mentioned components can be appropriately combined. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the gist of the above-mentioned embodiment.

[0168] Although the present invention has been described in detail and with reference to specific embodiments, it is apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2021-139604) filed on August 30, 2021 and a Japanese patent application (Patent Application No. 2022-072684) filed on April 26, 2022, the contents of which are incorporated by reference into this application. [Explanation of symbols]

[0169] 2 Automotive display device 10 Glass items 12 Coverslip 12A, 12B main surface 14 Frame 16 Adhesive layer 20 Curved section A1, A2 area F Length R radius of curvature R' corrected radius of curvature t Thickness

Claims

1. a cover glass having a first major surface and a second major surface; a frame bonded to the second main surface side of the cover glass via an adhesive layer; and the cover glass is provided with a curved portion that is convex toward 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; R' is represented by the following formula (1), and C １ is expressed by the following formula (2), the curved portion is C １ If C is greater than 0, the following formula (3) is satisfied. １ ≦0, the following formula (4) is satisfied: (A 1 +A 2 ) / L is 60 mm or less; Glass articles. [Equation 1] [Equation 2] [Equation 3] [Equation 4] where: R is the radius of curvature of the curved portion (mm), F is a length of a flat region in a first direction perpendicular to the bending axis of the curved portion when the flat region is provided adjacent to the curved portion in the first direction, and t is the thickness of the cover glass (mm), A １ is the area (mm ２ ) and A ２ is the area (mm ２ ) and E is the Young's modulus of the cover glass (GPa); L indicates the length (mm) of the curved portion in the first direction.

2. The curved portion having a convex shape toward the second main surface is C １ The glass article according to claim 1, further satisfying the following formula (6) when > 0: [Equation 7]

3. The cover glass also has a curved portion that is convex toward the first main surface, C ２ is expressed by the following formula (5), the curved portion that is convex toward the first main surface is C ２ >0, the following formula (6) is satisfied, and C ２ The glass article according to claim 1 or 2, which satisfies the following formula (7) when ≦0: [Equation 6] [Equation 7] [Equation 8]

4. a cover glass having a first major surface and a second major surface; a frame bonded to the second main surface side of the cover glass via an adhesive layer; and the cover glass is provided with a curved portion that is convex toward the first 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; R' is represented by the following formula (1), and C ２ is expressed by the following formula (5), the curved portion is C ２ >0, the following formula (6) is satisfied, and C ２ ≦0, the following formula (7) is satisfied: A glass article in which (A 1 +A 2 ) / L is 60 mm or less. [Equation 9] [Equation 10] [0011] [0012] where: R is the radius of curvature of the curved portion (mm), F is a length of a flat region in a first direction perpendicular to the bending axis of the curved portion when the flat region is provided adjacent to the curved portion in the first direction, and t is the thickness of the cover glass (mm), A １ is the area (mm ２ ) and A ２ is the area (mm ２ ) and E is the Young's modulus of the cover glass (GPa); L indicates the length (mm) of the curved portion in the first direction.

5. The glass article according to claim 1 , wherein the flat region is provided on both sides of the curved portion in the first direction.

6. 5. The glass article according to claim 1, wherein the adhesive layer includes both the first adhesive layer and the second adhesive layer, and the first adhesive layer and the second adhesive layer are made of different adhesive materials.

7. 5. The glass article according to claim 1, wherein the thickness t of the cover glass is 0.3 mm or more and 3.0 mm or less.

8. 5. The glass article according to claim 1, wherein the radius of curvature R of the curved portion is 50 mm or more and 10,000 mm or less.

9. 5. The glass article according to claim 1, wherein the Young's modulus E of the cover glass is 60 GPa or more and 90 GPa or less.

10. A display and the glass article according to any one of claims 1, 2 and 4 provided on the surface of the display. Automotive display device.

Images