Foldable glass member and stack assembly including the same

Abstract

A flexible glass member and a stack assembly including the glass member are provided. The flexible glass member is characterized by the following thickness profile: the glass member has a minimum thickness t min and a maximum thickness t max where t min is at least 10 μm and t max is at most 400 μm, the overall thickness variation of the glass member is in the range of 10 μm to 390 μm, and the maximum local thickness variation of the glass member over a measurement path of 4 mm is at most 69 μm. A method of manufacturing the glass member or a stack assembly including or comprising the same is also provided.

Description

Technical Field

[0001] The present invention relates to a flexible glass member and a stack assembly including the glass member. The present invention also relates to a method for manufacturing the glass member or a stack assembly including the same.

Background Art

[0002] As screens get larger, the boundary between smartphones and tablets is disappearing. However, those large screens limit the portability and usability of smartphones. As a solution, foldable displays are becoming increasingly popular for consumer electronics devices. Having a foldable screen has the advantage that the footprint of the device in the folded state is equivalent to that of a device with a normal-sized rigid cover and still fits in the user's pocket. However, when needed, by opening the fold, the screen can be enlarged to almost tablet size, thus providing full functionality and an enhanced user experience. For current foldable devices, ultra-thin glass (UTG) is used as the cover glass for the display. Its flexibility and foldability are essential for folding applications. However, a drawback of UTG is its minimal thickness and thus its low resistance to sharp impacts or scratches.

[0003] To achieve higher impact resistance, the glass has to be thicker, which is contrary to bendability. Therefore, cover glasses having, for example, a hinge structure or a thinned fold area have been developed. Those cover glasses comprise thicker glass in the main display area and a thinned fold area for the required flexibility. However, US Patent No. 2021 / 0107826 (US2021 / 0107826 A1) discloses problems in a glass member including thicker glass in the main display area and thinner glass in the fold area. In particular, it is disclosed that the glass member may undulate or even break during chemical strengthening. In particular, the tilt angle from the fold area to the thicker area is large, reaching even from 1° to 20°.

[0004] Also, the next generation of foldable display models may further feature more than one fold area. Well-known solutions are, for example, so-called S-type or G-type fold displays. Each cover glass has to feature two fold areas, which have to be bent at two different bending radii. Furthermore, one of the main surfaces and a part of one of the bending areas are on the unprotected outside of the device. In this case, the exposed fold area is particularly vulnerable because the glass is under tensile stress in its folded state. For those foldable displays, differential glass thickness is even more important.

[0005] Having a thinned or structured fold region in such a display stack can be disadvantageous because a sharp thickness change in the cover glass or structured portion can pose problems for the optical properties of the glass. Both the thinned region and the structured region must be filled with a suitable index-matching polymer filler so that steps or vias in thickness are not visible. Ultimately, sharp transition areas from thicker to thinner glass and vice versa can, in the worst case, become a defined failure point. Similarly, delicate structured areas can become more prone to breakage. Having them in the exposed area of the device can cause stability issues for the display.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] Accordingly, an object of the present invention is to provide a glass member suitable for the above-described foldable device, having at least one fold area and bendability together with improved impact resistance (e.g., in a pen drop resistance test), and a stack assembly including the glass member. Further, an object of the present invention is to provide various manufacturing methods that enable the manufacture of the above-described glass member by various technical approaches.

Means for Solving the Problems

[0008] The solution to the above problems is presented in the form of a glass member having a homogeneous thickness transition not only in the fold area but also in the flat display area in the present invention. The thickness profile of the glass member of the present invention can follow a continuous function, particularly without a sharp change in the thickness value.

[0009] One embodiment of the present invention is similar to a display for double folding (S-shaped folding), and has a wedge-shaped thickness profile that transitions from a maximum thickness (at the exposed main surface of the display) through an outer fold region (having a larger bending radius) to an inner folded display area having a smaller bending radius, and (when folded) has two protected main surfaces (see FIGS. 1A and 1D).

[0010] For single-fold displays, other embodiments may resemble a glass member having a thickness profile with a constriction having two thicker outer regions similar to the main surfaces and a thinner central region similar to the fold region (see FIG. 3A). A reverse thickness profile, i.e., a bell-shaped glass having a thick central region and two thinner outer regions, may resemble other embodiments suitable for so-called "accordion" display assemblies (see FIGS. 1B, 1E, and 3B).

[0011] More complex structures may resemble a glass member having a wavy contour on one surface, such as for multiple folds, e.g., "M / W type" or additional folding (see FIGS. 1C and 1F), or a glass member where one side can be rolled up while the other side remains straight or can be further folded (see FIG. 2).

[0012] A characteristic feature of such glass members would be that thickness variations occur not only in the fold regions but also at the smooth transitions from the main surfaces to the fold regions. An advantage of such glass members would be that since they do not have sharp transitions in thickness, there is a lower likelihood of optical problems occurring. Further, such glass members require no or substantially reduced amounts of index-matching fillers, making them easier to mount in a display stack.

[0013] Furthermore, the glass member is very stable upon chemical strengthening and has a reduced risk of waviness and breakage given the very smooth thickness transition.

[0014] Exemplary dimensions and bend radii for S-folded glass elements are set forth in FIG. 6 and its description. The bend radius of such glass elements may be calculated as follows: For each bend axis at bend radius R, at width 4.378·R (along a direction perpendicular to the bend axis, not parallel to it), the glass element is preferably bent according to the following formula:

number

[0015] The thickness of those types of glass members can vary from 10 μm in the thinnest area to 400 μm in the thickest area, and therefore the total thickness variation (TTV=maximum thickness-minimum thickness) of such glass members varies from 10 μm to 390 μm.

[0016] The local thickness variation (LTV) is specified as the difference between the maximum thickness LT and the minimum thickness ST of the glass element along a measurement path of 4 mm. Thus, since the LTV is given for a particular measurement path of 4 mm, depending on the position of the measurement path on the glass element, the different local thickness variations LTV i The measurement path can be placed on the glass member in any orientation. i Value is LTV i =LT i -ST i (i=1, 2, ..., n, where n is the number of potentially possible different measurement paths on a 4 mm glass part). The maximum local thickness variation (LTV) of the glass part is specified as max ) is the total LTV of the glass components i The maximum value of the minimum local thickness variation (LTV) of the glass element. min ) is the LTV max All LTVs of glass components with measurement paths oriented parallel to the underlying measurement path ofi is the minimum value. Generally, the direction of the measurement path can be described based on three spatial directions x, y, and z, where x and y correspond to the length and width directions of the glass member, respectively, and z corresponds to the thickness direction of the glass member. LTV min The measurement path underlying LTV max being parallel to the measurement path underlying LTV

[0017] In particular, the edges of the glass member can have various geometric properties, for example due to chamfer structures. Therefore, the edge regions are preferably excluded from the determination of the TTV and LTV values. Preferably, the TTV and / or LTV relate to the thickness of the glass member at least 0.5 mm away from the edge of the glass member. Thus, for example, a smaller thickness at the edge due to a chamfer structure is not considered for determining the minimum thickness t min of the glass member. Rather, t min is the minimum thickness of the glass member at a distance of at least 0.5 mm from the edge. Similarly, the 4 mm measurement path for determining the LTV preferably does not include positions closer than 0.5 mm to the edge.

[0018] The above problem is solved by the subject matter of the claims. The above problem is particularly a glass member having a first surface and a second surface, with the following thickness profile: · The glass member has a minimum thickness t min and a maximum thickness t max where t min is at least 10 μm and t max is at most 400 μm, · The total thickness variation (TTV) of the glass member is in the range of 10 μm to 390 μm, and · The maximum local thickness variation (LTV max ) over a 4 mm measurement path is at most 69 μm characterized by the glass member.

[0019] TTV can be specifically defined as, in particular, t max -t min and can be measured, for example, in micrometers. The thicknesses of the glass members at various positions can be measured, for example, with a micrometer.

[0020] The first surface and the second surface of the glass member are also referred to as the two main surfaces of the glass member.

[0021] The minimum thickness t min may be in the range of, for example, 10 to 100 μm, 10 to 90 μm, 10 to 80 μm, 15 to 70 μm, 15 to 60 μm, 20 to 50 μm, 20 to 45 μm, 25 to 40 μm, 25 to 35 μm, or 25 to 30 μm. The minimum thickness t min may be, for example, at least 10 μm, at least 15 μm, at least 20 μm, or at least 25 μm. The minimum thickness t min may be, for example, at most 100 μm, at most 90 μm, at most 80 μm, at most 70 μm, at most 60 μm, at most 50 μm, at most 45 μm, at most 40 μm, at most 35 μm, at most 30 μm, or less than 30 μm, for example, at most 25 μm.

[0022] The maximum thickness t max may be in the range of, for example, 60 to 400 μm, 60 to 350 μm, 65 to 300 μm, 65 to 250 μm, 70 to 200 μm, 70 to 150 μm, 75 to 140 μm, 75 to 130 μm, 80 to 120 μm, 80 to 110 μm, 85 to 100 μm, or 85 to 95 μm. The maximum thickness t max may be, for example, at least 60 μm, at least 65 μm, at least 70 μm, at least 75 μm, at least 80 μm, or at least 85 μm. The maximum thickness t max may be, for example, at most 400 μm, at most 350 μm, at most 300 μm, at most 250 μm, at most 200 μm, at most 150 μm, at most 140 μm, at most 130 μm, at most 120 μm, at most 110 μm, at most 100 μm, or at most 95 μm. In some embodiments, t max is at most 800 μm, at most 700 μm, at most 600 μm, at most 500 μm.

[0023] t max / t min The ratio of t max / t min may be in the range of, for example, 3:2 to 40:1, 2:1 to 30:1, 2:1 to 20:1, 5:2 to 12:1, 5:2 to 10:1, 3:1 to 8:1, 3:1 to 6:1, or 7:2 to 5:1. t max / t min The ratio of may be, for example, at least 3:2, at least 2:1, at least 5:2, at least 3:1, or at least 7:2.

[0024] The TTV may be in the range of, for example, 10 to 390 μm, 10 to 310 μm, 20 to 230 μm, 20 to 150 μm, 30 to 140 μm, 40 to 125 μm, 40 to 100 μm, 50 to 80 μm, or 50 to 70 μm. The TTV may be, for example, at least 10 μm, at least 20 μm, at least 30 μm, at least 40 μm, or at least 50 μm. The TTV may be, for example, at most 390 μm, at most 310 μm, at most 230 μm, at most 150 μm, at most 140 μm, at most 125 μm, at most 100 μm, at most 80 μm, or at most 70 μm.

[0025] The maximum local thickness variation (LTV) of the glass member over a 4 mm measurement path max ) may be in the range of, for example, 0.1 to 69 μm, 0.2 to 50 μm, 0.2 to 30 μm, 0.5 to 15 μm, 0.5 to 10 μm, 0.75 to 5.0 μm, 0.75 to 4.5 μm, 1.0 to 4.0 μm, 1.0 to 3.5 μm, 1.25 to 3.0 μm, 1.25 to 2.5 μm, or 1.5 to 2.0 μm. The LTV of the glass member over a 4 mm measurement path max may be, for example, at least 0.1 μm, at least 0.2 μm, at least 0.5 μm, at least 0.75 μm, at least 1.0 μm, at least 1.25 μm, or at least 1.5 μm. The LTV of the glass member over a 4 mm measurement path maxmay be, for example, up to 69 μm, up to 50 μm, up to 30 μm, up to 15 μm, up to 10 μm, up to 5.0 μm, up to 4.5 μm, up to 4.0 μm, up to 3.5 μm, up to 3.0 μm, up to 2.5 μm, or up to 2.0 μm. In some embodiments, the LTV of the glass member over a 4 mm measurement path max may be, for example, up to 10.0 μm, up to 9.0 μm, up to 8.0 μm, up to 7.0 μm, up to 6.0 μm, or up to 5.5 μm.

[0026] The minimum local thickness variation (LTV min ) of the glass member over a 4 mm measurement path may be in the range of, for example, 0.0 - 69 μm, 0.0 μm - 30 μm, 0.1 - 10 μm, 0.2 - 5.0 μm, 0.2 - 4.0 μm, 0.5 - 3.0 μm, 1.0 - 2.5 μm, or 1.0 - 2.0 μm. The LTV of the glass member over a 4 mm measurement path min may be, for example, 0.0 μm. Thus, there may be an area of the glass member where the thickness of the glass member does not change or does not substantially change over a 4 mm measurement path. However, the LTV of the glass member over a 4 mm measurement path min may be, for example, at least 0.1 μm, at least 0.2 μm, at least 0.5 μm, or at least 1.0 μm. The LTV of the glass member over a 4 mm measurement path min may be, for example, up to 69 μm, up to 30 μm, up to 10 μm, up to 5.0 μm, up to 4.0 μm, up to 3.0 μm, up to 2.5 μm, or up to 2.0 μm. In some embodiments, the LTV of the glass member over a 4 mm measurement path min may be, for example, up to 10.0 μm, up to 9.0 μm, up to 8.0 μm, up to 7.0 μm, up to 6.0 μm, or up to 5.5 μm.

[0027] LTV min / LTV maxThe ratio may be in the range of, for example, 0:1 to 1:1, 1:100 to 99:100, 1:50 to 99:100, 1:20 to 49:50, 1:10 to 49:50, 1:5 to 19:20, 1:2 to 9:10, 2:3 to 8:9, or 4:5 to 7:8. When the glass member includes an area where the thickness of the glass member does not change or does not substantially change over a measurement path of 4 mm in thickness, LTV min / LTV max The ratio may be, for example, 0:1. However, LTV min / LTV max The ratio may be, for example, at least 1:100, at least 1:50, at least 1:20, at least 1:10, at least 1:5, at least 1:2, at least 2:3, or at least 4:5. LTV min / LTV max The ratio may be, for example, 1:1, or essentially 1:1. LTV min / LTV max The closer the ratio of LTV min / LTV max is to 1:1, the more uniform the thickness variation across the glass member becomes. In particular, a glass member having a wedge-shaped thickness profile may have a ratio of LTV min / LTV max of 1:1, or essentially 1:1. LTV min / LTV max The ratio may be, for example, at most 1:1, at most 99:100, at most 49:50, at most 19:20, at most 9:10, at most 8:9, or at most 7:8. In some embodiments, the ratio of LTV min / LTV max is particularly low, for example, at most 1:5, at most 1:10, or at most 1:100. In other embodiments, the ratio of LTV min / LTV max is particularly high, for example, at least 9:10, at least 19:20, or at least 99:100.

[0028] The ratio of LTV max / TTV can be expressed as a percentage value in the present disclosure. In particular, LTV maxUnless otherwise specified, it is always shown for a measurement path of 4 mm. However, in order to simplify the expression and make it easier to read, when referring to LTV max / TTV, the phrase "over a 4-mm measurement path" may be omitted. For example, if LTV max is 1 μm over a 4-mm measurement path and TTV is 100 μm, this disclosure simply relates to the ratio of LTV max / TTV being 1%.

[0029] The ratio of LTV max / TTV may be in the range of, for example, 0.1% to 50.0%, 0.2% to 25.0%, 0.5% to 10.0%, or 1.0% to 5.0%. The ratio of LTV max / TTV may be, for example, at least 0.1%, at least 0.2%, at least 0.5%, or at least 1.0%. The ratio of LTV max / TTV may be, for example, at most 50.0%, at most 25.0%, at most 10.0%, or at most 5.0%.

[0030] The glass member of the present invention may be, for example, a sheet or a sheet-like member, particularly a round member, or a rectangular or square member having a length and a width. Both the length and the width of the glass member are preferably much longer than the thickness of the member. For example, the length and / or the width may be at least 1 mm, at least 2 mm, at least 5 mm, at least 10 mm, at least 15 mm, at least 20 mm, at least 25 mm, at least 30 mm, at least 40 mm, or at least 50 mm. For example, the length and / or the width may be at most 500 mm, at most 400 mm, at most 300 mm, at most 200 mm, at most 150 mm, at most 125 mm, at most 100 mm, or at most 70 mm. The ratio of the length to the width may be 1:1 or more. In some embodiments, the glass member may have, in particular, a notch for a front camera in a smartphone application, and / or a hole or a recess for a camera and / or a microphone or a speaker.

[0031] In one aspect of the present invention, the glass member may have a length in the range of 10 mm to 500 mm and / or a width in the range of 5 mm to 400 mm, for example, a length and / or a width in the range of 10 to 400 mm, 15 to 300 mm, 20 to 200 mm, 25 to 150 mm, 30 to 125 mm, 40 to 100 mm, or 50 to 70 mm. The length and / or the width may be, for example, at least 5 mm, at least 10 mm, at least 15 mm, at least 20 mm, at least 25 mm, at least 30 mm, at least 40 mm, or at least 50 mm. The length and / or the width may be, for example, at most 500 mm, at most 400 mm, at most 300 mm, at most 200 mm, at most 150 mm, at most 125 mm, at most 100 mm, or at most 70 mm.

[0032] In particular, the glass member of the present invention may have a wedge-shaped thickness profile. The wedge-shaped thickness profile is shown illustratively and schematically in FIGS. 1A and 6. The wedge-shaped thickness profile may be characterized in that the glass member does not include a region where the first surface and the second surface are parallel to each other. In other words, the transition from the maximum thickness t max to the minimum thickness t min is preferably monotonic. Accordingly, the maximum thickness t max and the minimum thickness t min of the glass member are located at opposite ends of the glass member and not at the center of the glass member.

[0033] The average surface roughness (R a ) is a measure of the surface texture. It is quantified by the vertical deviation from the ideal form of the actual surface. Conventionally, the amplitude parameters characterize the surface based on the vertical deviation from the mean line of the roughness profile. R a is the arithmetic mean of the absolute values of those vertical deviations. It can be specified in accordance with DIN EN ISO 4287:2010-07.

[0034] The average surface roughness R aIt is preferably identified using an atomic force microscope (AFM), particularly using the BRUKER Dimension Icon model. The test area is preferably 2×2 μm 2 or more, or 10×10 μm 2 or more.

[0035] Preferably, the average surface roughness R of the first surface and / or the second surface a is, particularly for an area of 2×2 μm 2 or 10×10 μm 2 at most 0.80 nm, at most 0.70 nm, at most 0.60 nm, at most 0.50 nm, at most 0.40 nm, at most 0.30 nm, more preferably at most 0.25 nm, more preferably at most 0.20 nm, more preferably at most 0.15 nm. The average surface roughness R of the first surface and / or the second surface a is, particularly for an area of 2×2 μm 2 or 10×10 μm 2 can be, for example, at least 0.05 nm, at least 0.08 nm, at least 0.10 nm, at least 0.11 nm, or at least 0.12 nm. The average surface roughness R of the first surface and / or the second average surface a is, particularly for an area of 2×2 μm 2 or 10×10 μm 2 can be in the range of, for example, 0.05 - 0.80 nm, 0.05 - 0.70 nm, 0.08 - 0.60 nm, 0.08 - 0.50 nm, 0.10 - 0.40 nm, 0.11 - 0.30 nm, 0.11 - 0.25 nm, 0.12 - 0.20 nm, or 0.12 - 0.15 nm.

[0036] The present invention relates to a glass member characterized by a thickness profile that provides a combination of very good impact resistance and very good bending properties. This is particularly advantageous for using glass members in bendable electronic devices such as smartphones that can be bent and must withstand various external impacts without breaking.

[0037] The measure for impact resistance is the pen drop height. The higher the pen drop height, the higher the impact resistance. The pen drop height is the breaking height specified in the pen drop test, in which the glass member is attached to one surface of a 150 μm thick substrate, and the substrate consists of a 25 μm thick pressure-sensitive adhesive (PSA) material layer, a 50 μm thick polyethylene (PE) layer, another 25 μm thick pressure-sensitive adhesive (PSA) layer, and another 50 μm thick polyethylene (PE) layer from the side in contact with the glass to the side in contact with the marble stage. Under the 150 μm thick substrate, there is a flat 10 cm thick marble stage with a polished and smooth surface. Subsequently, on the other surface of the upward-facing glass member (i.e., the surface where the pen drop height is actually tested), a 14 g ballpoint pen (manufactured by Chenguang) with a tungsten carbide ball diameter of 0.5 mm is used to increase the height from 5 mm and apply an impact until the glass breaks. Then, the breaking height is recorded as the pen drop height.

[0038] The first surface and / or the second surface of the glass member may include at least one impact-resistant region characterized by an impact resistance corresponding to a pen drop height of at least 5 mm, at least 10 mm, at least 15 mm, at least 20 mm, at least 25 mm, at least 30 mm, at least 35 mm, at least 40 mm, at least 45 mm, at least 50 mm, at least 75 mm, at least 100 mm, at least 150 mm, at least 200 mm, at least 300 mm, at least 400 mm, or at least 500 mm. The first surface and / or the second surface of the glass member may include at least one impact-resistant region characterized by an impact resistance corresponding to a pen drop height of up to 10,000 mm, up to 5,000 mm, up to 4,000 mm, up to 3,000 mm, up to 2,000 mm, up to 1,500 mm, or up to 1,000 mm. In some embodiments, the first surface and / or the second surface of the glass member may include at least one impact-resistant region characterized by an impact resistance corresponding to a pen drop height of up to 500 mm, up to 450 mm, up to 400 mm, up to 350 mm, up to 300 mm, up to 250 mm, up to 200 mm, up to 150 mm, up to 100 mm, or up to 75 mm. The first surface and / or the second surface of the glass member may include at least one impact-resistant region characterized by an impact resistance corresponding to a pen drop height in the range of 5 - 500 mm, 10 - 450 mm, 15 - 400 mm, 20 - 350 mm, 25 - 300 mm, 30 - 250 mm, 35 - 200 mm, 40 - 150 mm, 45 - 100 mm, or 50 - 75 mm. In other embodiments, the first surface and / or the second surface of the glass member may include at least one impact-resistant region characterized by an impact resistance corresponding to a pen drop height in the range of 75 - 10,000 mm, 100 - 5,000 mm, 150 - 4,000 mm, 200 - 3,000 mm, 300 - 2,000 mm, 400 - 1,500 mm, or 500 - 1,000 mm.

[0039] It is also possible to normalize the pen drop height with respect to the thickness of the impact resistance region of the glass member. The normalized pen drop height can be obtained as the ratio of the pen drop height (μm) to the square of the average thickness of the corresponding impact resistance region of the glass member (μm 2 ). For example, if a particular glass member includes an impact resistance region characterized by an impact resistance corresponding to a pen drop height of 10 mm (= 10,000 μm), and the average thickness of the glass member in each impact resistance region is 50 μm, the normalized pen drop height can be obtained by dividing 10,000 μm by 50 2 μm 2 , and a value of 4.0 per μm is obtained for the normalized pen drop height.

[0040] The first surface and / or the second surface of the glass member may include at least one impact-resistant region characterized by an impact resistance corresponding to a normalized pen drop height of at least 2.0, at least 2.5, at least 3.0, at least 3.5, at least 4.0, at least 4.5, at least 5.0, at least 5.5, at least 6.0, at least 6.5, at least 7.0, at least 7.5, at least 8.0, at least 8.5, at least 9.0, at least 9.5, at least 10.0, or at least 10.5 per micrometer. The first surface and / or the second surface of the glass member may include at least one impact-resistant region characterized by an impact resistance corresponding to a normalized pen drop height of at most 60.0, at most 50.0, at most 45.0, at most 40.0, at most 35.0, at most 30.0, at most 25.0, at most 20.0, at most 18.0, at most 16.0, at most 14.0, at most 12.0, or at most 11.0 per micrometer. The first surface and / or the second surface of the glass member may include at least one impact-resistant region characterized by an impact resistance corresponding to a normalized pen drop height in the range of 2.0 - 60.0, 2.5 - 60.0, 3.0 - 60.0, 3.5 - 60.0, 4.0 - 60.0, 4.5 - 60.0, 5.0 - 50.0, 5.5 - 45.0, 6.0 - 40.0, 6.5 - 35.0, 7.0 - 30.0, 7.5 - 25.0, 8.0 - 20.0, 8.5 - 18.0, 9.0 - 16.0, 9.5 - 14.0, 10.0 - 12.0, or 10.5 - 11.0 per micrometer.

[0041] The glass member may include at least one flexible region that is particularly suitable for withstanding tensile stresses that occur on the first surface and / or the second surface when the glass member is bent. This is reflected by the fact that the flexible region has a particularly high ball-on-ring breaking force and / or two-point bending strength. In particular, at least one flexible region may partially or entirely overlap with, or alternatively may not overlap with, at least one impact-resistant region. For example, 0% to 100% of at least one flexible region, such as at least 10%, at least 25%, at least 50%, at least 75%, at least 90%, at least 95%, at least 99% or 100% of at least one flexible region, and / or up to 99%, up to 95%, up to 90%, up to 75%, up to 50%, up to 25%, up to 10%, up to 5%, up to 1% or 0% of at least one flexible region may be eligible as an impact-resistant region in the context of the present invention. Similarly, 0% to 100% of at least one impact-resistant region, such as at least 10%, at least 25%, at least 50%, at least 75%, at least 90%, at least 95%, at least 99% or 100% of at least one impact-resistant region, and / or up to 99%, up to 95%, up to 90%, up to 75%, up to 50%, up to 25%, up to 10%, up to 5%, up to 1% or 0% of at least one impact-resistant region may be eligible as a flexible region in the context of the present invention.

[0042] As schematically depicted in FIG. 7, the ball-on-ring breaking force can be tested by placing the surface 75 of the glass member 71 on the steel ring 72, which has an inner diameter of 4 mm and an outer diameter of 6 mm. The ring 72 has a depth of 3 mm, the wall of the ring 72 is 1 mm thick, and has a tip of the wall with a semi-circle having a diameter of 1 mm as a cross-section. To test the ball-on-ring breaking force, the end of the glass member 71 is at least 20 mm away from the center of the ring 72. A tungsten carbide ball 73 having a diameter of 1 mm is pressed against the surface 74 of the glass member 71 along the central axis of the ring 72 at a speed of 5 mm / min until the glass is crushed. The force at the time of breakage is recorded as the ball-on-ring breaking force.

[0043] Depending on which surface of the glass member 71 is in contact with the ring 72 or the ball 73 respectively, the ball-on-ring breaking force of the first surface or the second surface of the glass member 71 can be tested. The ball-on-ring test described herein is adjusted to identify the ball-on-ring breaking force of a specific surface of the glass member 71 that contacts the steel ring 72. For example, when the second surface of the glass member 71 is the surface 75 that contacts the steel ring 72, while the first surface of the glass member 71 is the surface 74 that contacts the ball 73, the product of the ball-on-ring test is the ball-on-ring breaking force of the second surface. However, when the first surface of the glass member 71 is the surface 75 that contacts the steel ring 72, while the second surface of the glass member 71 is the surface 74 that contacts the ball 73, the product of the ball-on-ring test is the ball-on-ring breaking force of the first surface. Tensile stress is generated at the surface 75 of the glass member 71 during the ball-on-ring test. Therefore, the product of the ball-on-ring test is the ball-on-ring breaking force of the surface 75.

[0044] However, if the present disclosure relates to a glass member that includes at least one flexible region characterized by a specific ball-on-ring breaking force and / or a specific two-point bending strength, the present disclosure does not distinguish between the two surfaces of the glass member unless otherwise indicated. Rather, the present disclosure relates to the ball-on-ring breaking force and / or the two-point bending strength achieved at the first surface and / or the second surface within the flexible region of the glass member, unless otherwise indicated. Accordingly, if the ball-on-ring breaking force and / or the two-point bending strength is achieved at the first surface and / or the second surface within a specific region of the glass member, the glass member includes at least one flexible region characterized by the ball-on-ring breaking force and / or the two-point bending strength, respectively, unless otherwise indicated.

[0045] The glass member can include at least one flexible region characterized by a ball-on-ring breaking force of at least 1.0 N, at least 2.0 N, at least 5.0 N, at least 7.5 N, at least 10.0 N, at least 12.5 N, at least 15.0 N, or at least 17.5 N. The glass member can include at least one flexible region characterized by a ball-on-ring breaking force of at most 50.0 N, at most 45.0 N, at most 40.0 N, at most 35.0 N, at most 30.0 N, at most 25.0 N, at most 22.5 N, or at most 20.0 N. The glass member can include at least one flexible region characterized by a ball-on-ring breaking force in the range of 1.0 - 50.0 N, 2.0 - 45.0 N, 5.0 - 40.0 N, 7.5 - 35.0 N, 10.0 - 30.0 N, 12.5 - 25.0 N, 15.0 - 22.5 N, or 17.5 - 20.0 N.

[0046] The particularly good bendability of the glass member of the present invention is also reflected in that the two-point bending strength (2PB strength) is particularly high, especially in the flexible region. To test the 2PB strength, the glass member is arranged in a U-shape between two parallel metal plates. The two plates are large enough to cover the entire glass member. Then, one of the plates is moved towards the other at a speed of 60 mm / min while maintaining parallelism until the glass member breaks. The 2PB strength is σ = 1.198Ed / (D - d) calculated by the formula, where σ is the calculated 2PB strength, E is the Young's modulus of the glass, d is the thickness of the glass member, and D is the distance between the two plates at the time of fracture.

[0047] The product of the 2PB test is the 2PB strength of the surface of the glass member that was the outer surface of the bend. For example, when the glass member is bent such that the second surface of the glass member is the outer surface of the bend while the first surface of the glass member is the inner surface of the bend, the product of the 2PB test is the 2PB strength of the second surface of the glass member. However, as described above, when the present disclosure relates to a glass member including at least one flexible region characterized by a specific two-point bending strength, unless otherwise indicated, the present disclosure does not distinguish between the two surfaces of the glass member. Rather, the present disclosure relates to the two-point bending strength achieved at the first surface and / or the second surface within the flexible region of the glass member, unless otherwise indicated. Accordingly, when the two-point bending strength is achieved at the first surface and / or the second surface within a specific region of the glass member, the glass member includes at least one flexible region characterized by the respective two-point bending strengths, unless otherwise indicated.

[0048] The glass member may include at least one flexible region characterized by a 2PB strength of, for example, at least 1000 MPa, at least 1250 MPa, at least 1300 MPa, at least 1500 MPa, at least 1750 MPa, at least 2000 MPa, at least 2250 MPa, at least 2500 MPa, at least 2750 MPa, or at least 3000 MPa. The glass member may include at least one flexible region characterized by a 2PB strength of, for example, at most 10,000 MPa, at most 7500 MPa, at most 6750 MPa, at most 6000 MPa, at most 5000 MPa, at most 4500 MPa, at most 4000 MPa, at most 3750 MPa, at most 3500 MPa, or at most 3250 MPa. The glass member may include at least one flexible region characterized by a 2PB strength in the range of, for example, 1000 - 10,000 MPa, 1250 - 7500 MPa, 1300 - 6750 MPa, 1500 - 6000 MPa, 1750 - 5000 MPa, 2000 - 4500 MPa, 2250 - 4000 MPa, 2500 - 3750 MPa, 2750 - 3500 MPa, or 3000 - 3250 MPa.

[0049] The glass member may include, for example, at least 1, at least 2, at least 3, or at least 4 flexible regions. The glass member may include, for example, at most 50, at most 20, at most 10, or at most 5 flexible regions. The number of flexible regions may be, for example, 1 - 50, 2 - 20, 3 - 10, or 4 - 5. For example, in the case of a rollable glass member, the entire rollable region may be regarded as a flexible region.

[0050] The glass member may include at least one flexible region characterized by, for example, no breakage when the glass member is held at a bending radius R of 5.0 mm at the center of the flexible region for 60 minutes, particularly at a temperature of 25 °C and a relative humidity of 40%.

[0051] The glass member may include at least one flexible region characterized by, for example, no breakage when the glass member is held at a bending radius R of 1.5 mm at the center of the flexible region for 60 minutes, particularly at a temperature of 25 °C and a relative humidity of 40%.

[0052] The glass member is, for example · at least one first flexible region characterized by no breakage when the glass member is held at a first bending radius R of 1.5 mm at the center of the first flexible region for 60 minutes, and 1 · at least one second flexible region characterized by no breakage when the glass member is held at a second bending radius R of 5.0 mm at the center of the second flexible region for 60 minutes · at least one second flexible region characterized by no breakage when the glass member is held at a second bending radius R of 5.0 mm at the center of the second flexible region for 60 minutes 2 and may include .

[0053] The width of the flexible region may be defined as 4.378·R along a direction perpendicular to the bending axis forming the center of the flexible region. The average thickness t of the glass member across the width of the flexible region avg may be, for example, as follows:

Equation

[0054] The warp can be measured, for example, by placing the glass member on a flat surface and then recording the longest distance between the lower surface of the glass member and the flat surface as the warp. The warp can be measured, for example, particularly by means of a set of gap gauges having a resolution of 0.01 mm. When used within the present application, the term "warp" relates to the warp of the glass member in a state where it is not folded and not bent, unless otherwise indicated.

[0055] The glass member of the present invention may have a warp of, for example, at least 0.005 mm, at least 0.01 mm, at least 0.02 mm, at least 0.03 mm, at least 0.05 mm, at least 0.1 mm, at least 0.5 mm, at least 1.0 mm, or at least 2.0 mm. The glass member of the present invention may have a warp of, for example, at most 10.0 mm, at most 7.5 mm, at most 5.0 mm, at most 2.5 mm, at most 2.0 mm, at most 1.5 mm, at most 1.0 mm, at most 0.5 mm, at most 0.2 mm, or at most 0.1 mm. The glass member of the present invention may have a warp in the range of, for example, 0.005 to 10.0 mm, 0.01 to 7.5 mm, 0.02 to 5.0 mm, 0.03 to 2.5 mm, 0.05 to 2.5 mm, 0.1 to 10.0 mm, 0.5 to 7.5 mm, 1.0 to 5.0 mm, or 2.0 to 2.5 mm, or 0.005 to 2.0 mm, 0.01 to 1.5 mm, 0.02 to 1.0 mm, 0.01 to 0.1 mm, 0.02 to 0.5 mm, or 0.005 to 0.2 mm. This warp is also referred to as an absolute warp and indicates the warp of the glass member.

[0056] However, it is also possible to specify the relative warp of the glass member, particularly the area relative warp and / or the length relative warp.

[0057] The warp of the glass member can be shown, for example, by normalizing it with respect to the surface area of one of the two main surfaces of the glass member (area relative warp). Since both main surfaces of the glass member generally have the same surface area or substantially the same surface area, normalizing the warp with respect to any one of the two main surfaces gives the same result. For example, each of the two main surfaces of a glass member having a length of 50 mm and a width of 30 mm has a surface area of 30 × 50 mm 2 = 1500 mm 2 Similarly, each of the two main surfaces of a glass member having a length of 125 mm and a width of 40 mm has a surface area of 125 × 40 mm 2 = 5000 mm 2 If such a glass member having a surface area of 5000 mm for each of the two main surfaces 2 has a warp of 2.0 mm (= 2000 μm), the area relative warp is 2000 μm divided by 5000 mm2 Dividing by, that is, 1 mm 2 will be 0.4 μm per.

[0058] The glass member of the present invention is 1 mm 2 at least 1 nm per, 1 mm 2 at least 2 nm per, 1 mm 2 at least 5 nm per, 1 mm 2 at least 10 nm per, 1 mm 2 at least 20 nm per, 1 mm 2 at least 50 nm per, 1 mm 2 at least 100 nm per, or 1 mm 2 can have an area relative warp of at least 250 nm per. The glass member of the present invention is 1 mm 2 maximum 5.0 μm per, 1 mm 2 maximum 2.5 μm per, 1 mm 2 maximum 1.5 μm per, 1 mm 2 maximum 1.0 μm per, 1 mm 2 maximum 500 nm per, 1 mm 2 maximum 200 nm per, 1 mm 2 maximum 100 nm per, or 1 mm 2 can have an area relative warp of at most 50 nm per. The glass member of the present invention is 1 mm 2 0.02 - 5.0 μm per, 1 mm 2 0.05 - 2.5 μm per, 1 mm 2 0.10 - 1.5 μm per, 1 mm 2 0.25 - 1.0 μm per, 1 mm 2 1 - 500 nm per, 1 mm 2 2 - 200 nm per, 1 mm 2 5 - 100 nm per, or 1 mm 2 can have an area relative warp in the range of 10 - 50 nm per.

[0059] The warpage of the glass member can also be shown normalized with respect to the longest length of one of the two major surfaces of the glass member (length relative warpage). Since both major surfaces of the glass member generally have the same longest length or approximately the same longest length, normalizing the warpage with respect to either one of the two major surfaces gives the same result. For a glass member having a major surface with a round shape, the longest length is its diameter. For a glass member having a major surface with a rectangular shape, the longest length is its diagonal. For example, each of the two major surfaces of a glass member having a length of 50 mm and a width of 30 mm has a longest length of the square root of (30 2 mm 2 +50 2 mm 2 ) = approximately 58.3 mm. Similarly, each of the two major surfaces of a glass member having a length of 125 mm and a width of 40 mm has a longest length of the square root of (125 2 mm 2 +40 2 mm 2 ) = approximately 131.25 mm. If such a glass member having a longest length of 131.25 mm for each of the two major surfaces has a warpage of 2.0 mm (= 2000 μm), the length relative warpage will be 2000 μm divided by 131.25 mm, that is, approximately 15.2 μm per mm.

[0060] The glass member of the present invention may have a length warpage of at least 1 nm per 1 mm, at least 2 nm per 1 mm, at least 5 nm per 1 mm, at least 10 nm per 1 mm, at least 20 nm per 1 mm, at least 50 nm per 1 mm, at least 100 nm per 1 mm, or at least 250 nm per 1 mm. The glass member of the present invention may have a length warpage of at most 50.0 μm per 1 mm, at most 40.0 μm per 1 mm, at most 30.0 μm per 1 mm, at most 20.0 μm per 1 mm, at most 10.0 μm per 1 mm, at most 5.0 μm per 1 mm, at most 2.0 μm per 1 mm, or at most 1.0 μm per 1 mm. The glass member of the present invention may have a length warpage in the range of 20 nm to 50.0 μm per 1 mm, 50 nm to 40.0 μm per 1 mm, 100 nm to 30.0 μm per 1 mm, 250 nm to 20.0 μm per 1 mm, 1 nm to 1.0 μm per 1 mm, 2 nm to 2.0 μm per 1 mm, 5 nm to 10.0 μm per 1 mm, or 10 nm to 5.0 μm per 1 mm.

[0061] The glass member of the present invention is not limited to a specific glass composition. However, some glass compositions are particularly advantageous. In one embodiment, the glass may be a silicate glass, such as aluminosilicate glass, lithium aluminum silicate glass, or borosilicate glass. The glass may be soda-lime glass. The glass may contain an alkali metal oxide, such as Na 2 O, in a sufficient amount, particularly to enable chemical strengthening.

[0062] The glass may contain the following components in mass%: SiO 2 45.0 to 75.0 mass%, B 2 O 3 0 to 10.0 mass%, Al 2 O 3 2.5 to 25.0 mass%, Li 2 O 0 to 10.0 mass%, Na 2 O 5.0 to 20.0 mass%, K 2O 0 to 10.0 mass%, MgO 0 to 15.0 mass%, CaO 0 to 10.0 mass%, BaO 0 to 5.0 mass%, ZnO 0 to 5.0 mass%, TiO 2 0 to 5.0 mass%, ZrO 2 0 to 5.0 mass%, P 2 O 5 0 to 20.0 mass%. In a preferred embodiment, the glass consists of the components mentioned in the above list to an extent of at least 95.0 mass%, more preferably at least 97.0 mass%, and most preferably at least 99.0 mass%.

[0063] The terms "X-free" and "component X-free", when used within this application, preferably mean that the component X is essentially not contained therein, that is, such a component may exist as an impurity or contaminant at most in the glass, but is not added to the glass composition as an individual component. This means that the component X is not added in an essential amount. The non-essential amount according to the present invention is an amount less than 100 ppm (m / m), preferably less than 50 ppm, and more preferably less than 10 ppm. Accordingly, "X" can relate to any component, for example a lead cation or an arsenic cation. Preferably, the glass described within this application essentially does not contain components not mentioned within this disclosure.

[0064] In one embodiment, the glass may contain the following components in mass%: SiO 2 45.0 to 72.0 mass%, B 2 O 3 0 to 4.7 mass%, Al 2 O 3 4.0 to 24.0 mass%, Li 2 O 0 to 6.0 mass%, Na 2 O 8.0 to 18.0 mass%, K 2 O 0 to 8.0 mass%, MgO 0 to 10.0 mass%, CaO 0 to 3.0 mass%, BaO 0 to 2.0 mass%, ZnO 0 to 3.0 mass%, TiO 2 0 to 1.0 mass%, ZrO 2 0 to 4.6 mass%, P 2 O 5 0 to 15.0 mass%.

[0065] In one embodiment, the glass may contain the following components by mass%: SiO 2 51.0 to 65.0 mass%, B 2 O 3 0 to 4.7 mass%, Al 2 O 3 11.0 to 24.0 mass%, Li 2 O 0 to 6.0 mass%, Na 2 O 8.0 to 18.0 mass%, K 2 O 0 to 8.0 mass%, MgO 0 to 5.5 mass%, CaO 0 to 1.0 mass%, BaO 0 to 1.0 mass%, ZnO 0 to 3.0 mass%, TiO 2 0 to 1.0 mass%, ZrO 2 0 to 4.6 mass%, P 2 O 5 0 to 10.0 mass%.

[0066] In one embodiment, the glass may contain the following components by mass%: SiO 2 45.0 to 72.0 mass%, B 2 O 3 0 to 4.7 mass%, Al 2 O 3 4.0 to 24.0 mass%, Li 2 O 0 to 3.0 mass%, Na 2 O 8.0 to 18.0 mass%, K 2 O 0 to 8.0 mass%, MgO 0 to 5.5 mass%, CaO 0 to 1.0 mass%, BaO 0 to 2.0 mass%, ZnO 0 to 3.0 mass%, TiO 2 0 to 1.0 mass%, ZrO 2 0 to 3.0 mass%, P 2 O 5 0 to 15.0 mass%.

[0067] SiO 2 The lower limit of the amount may be, for example, at least 45 mass%, at least 51 mass%, or at least 55 mass%. SiO 2 The upper limit of the amount may be, for example, at most 75 mass%, at most 72 mass%, or at most 65 mass%.

[0068] B 2 O 3 The lower limit of the amount of may be, for example, at least 0.1% by mass, at least 0.2% by mass, or at least 0.5% by mass. B 2 O 3 The upper limit of the amount of may be, for example, at most 10% by mass, at most 5% by mass, at most 2% by mass, or at most 1% by mass. The glass may be, for example, free of B 2 O 3

[0069] Al 2 O 3 The lower limit of the amount of may be, for example, at least 2.5% by mass, at least 4% by mass, or at least 11% by mass. Al 2 O 3 The upper limit of the amount of may be, for example, at most 25% by mass, at most 24% by mass, or at most 20% by mass.

[0070] Li 2 The lower limit of the amount of O may be, for example, at least 0.1% by mass, at least 0.2% by mass, or at least 0.5% by mass. Li 2 The upper limit of the amount of O may be, for example, at most 10% by mass, at most 6% by mass, or at most 3% by mass. The glass may be, for example, free of Li 2 O

[0071] Na 2 The lower limit of the amount of O may be, for example, at least 5% by mass, at least 8% by mass, or at least 10% by mass. Na 2 The upper limit of the amount of O may be, for example, at most 20% by mass, at most 18% by mass, or at most 16% by mass.

[0072] K 2 The lower limit of the amount of O may be, for example, at least 0.5% by mass, at least 1% by mass, or for some variants at least 2% by mass. K 2 The upper limit of the amount of O may be, for example, at most 10% by mass, at most 8% by mass, at most 5% by mass, at most 3% by mass, or for some variants at most 2% by mass, or at most 1.5% by mass. The glass may be, for example, free of K 2 O​

[0073] The lower limit of the amount of MgO may be, for example, at least 0.5% by mass, at least 1% by mass, or at least 2% by mass. The upper limit of the amount of MgO may be, for example, at most 15% by mass, at most 10% by mass, or at most 5.5% by mass. The glass may be, for example, free of MgO.

[0074] The lower limit of the amount of CaO may be, for example, at least 0.1% by mass, at least 0.2% by mass, or at least 0.5% by mass. The upper limit of the amount of CaO may be, for example, at most 10% by mass, at most 3% by mass, or at most 1% by mass. The glass may be, for example, free of CaO.

[0075] P 2 O 5 The lower limit of the amount of may be, for example, at least 0.1% by mass, at least 0.2% by mass, or at least 0.5% by mass. P 2 O 5 The upper limit of the amount of may be, for example, at most 20% by mass, at most 15% by mass, or at most 10% by mass. The glass may be, for example, free of P 2 O 5 The glass may be, for example, free of.

[0076] The lower limit of the amount of BaO may be, for example, at least 0.1% by mass, at least 0.2% by mass, or at least 0.5% by mass. The upper limit of the amount of BaO may be, for example, at most 5% by mass, at most 2% by mass, or at most 1% by mass. The glass may be, for example, free of BaO.

[0077] The lower limit of the amount of ZnO may be, for example, at least 0.1% by mass, at least 0.2% by mass, or at least 0.5% by mass. The upper limit of the amount of ZnO may be, for example, at most 5% by mass, at most 3% by mass, or at most 1% by mass. The glass may be, for example, free of ZnO.

[0078] ZrO 2 The lower limit of the amount of may be, for example, at least 0.2% by mass, at least 0.5% by mass, or at least 1% by mass. ZrO 2The upper limit of the amount may be, for example, at most 5% by mass, at most 4.6% by mass, or at most 3% by mass. The glass may be, for example, free of ZrO 2 and may be free of it.

[0079] TiO 2 The lower limit of the amount may be, for example, at least 0.1% by mass, at least 0.2% by mass, or at least 0.5% by mass. TiO 2 The upper limit of the amount may be, for example, at most 5.0% by mass, at most 2.5% by mass, at most 1.5% by mass, or at most 1% by mass. The glass may be, for example, free of TiO 2 and may be free of it.

[0080] The glass member may contain, for example, the following components in the indicated amounts (mass%):

Table 1

[0081] The Young's modulus E of the glass may be in the range of, for example, 60 to 80 GPa, or 70 to 75 GPa.

[0082] The glass member of the present invention can be chemically strengthened, particularly by subjecting the glass member to ion exchange treatment.

[0083] The compressive stress (CS) (also referred to as "pressure stress" or "surface stress") is the stress generated from the action of substitution exerted on the glass network through the glass surface after ion exchange, while no deformation occurs in the glass.

[0084] The "penetration depth" or "depth of ion exchange layer" or "ion exchange depth" ("layer depth" or "depth of ion exchange layer", DoL) is the thickness of the glass surface layer where ion exchange occurs and compressive stress is generated. The compressive stress CS and the penetration depth DoL can be measured optically (particularly by the mechanism of the waveguide) using a commercially available stress meter FSM6000 (for example, Lucere Co., Ltd., Tokyo, Japan).

[0085] When CS is induced on one or both sides of a single glass sheet, tensile stress must be induced in the central region of the glass in order to balance the stress according to the third principle of Newton's law, which is referred to as internal tensile stress (CT). CT can be calculated from the measured CS value and DoL value.

[0086] Ion exchange means that the glass is hardened or chemically strengthened by an ion exchange process (also referred to as chemical strengthening), and the process is well known to those skilled in the art of glass manufacturing and processing. The strengthening process can be carried out by immersing a glass layer in a salt bath containing monovalent ions and exchanging them with alkali ions inside the glass. The monovalent ions in the salt bath have a larger radius than the alkali ions inside the glass. The compressive stress on the glass is formed after ion exchange due to the intrusion of larger ions into the network of the glass. After ion exchange, the strength and flexibility of the glass are significantly improved. Furthermore, the CS induced by chemical strengthening improves the bending properties of the strengthened glass layer and enhances the scratch resistance of the glass layer. Typical salts used for chemical strengthening are, for example, K + -containing molten salts or salt mixtures. Any salt bath for chemical strengthening is a Na + -containing and / or K + -containing molten salt bath or a mixture thereof. Any salt is NaNO 3 , KNO 3 , NaCl, KCl, Na 2 SO 4 , K 2 SO 4 , Na 2 CO 3 , K 2 CO 3 and K 2 Si 2 O 5 and so on. Additives, such as NaOH, KOH and other sodium salts or potassium salts, are also used to better control the rate of ion exchange for chemical strengthening. Ion exchange is, for example, KNO 3It can be carried out at a temperature in the range of 300°C to 480°C, particularly 340°C to 450°C, or 390°C to 450°C, for a time of, for example, 30 seconds to 48 hours, particularly about 20 minutes. Chemical strengthening is not limited to a single step. It can include multiple steps in one or more salt baths having various concentrations of alkali metal ions in order to achieve better strengthening performance. Accordingly, the glass layer to be chemically strengthened can be strengthened in a single step or multiple steps, for example, a two-step process. Two-step chemical strengthening is particularly applicable to Li 2 O-containing glass because lithium can be exchanged with both sodium ions and potassium ions.

[0087] The chemically strengthened glass member of the present invention can have a surface compressive stress CS1 at the first surface and / or a surface compressive stress CS2 at the second surface.

[0088] CS1 and / or CS2 can be, for example, at least 300 MPa, at least 350 MPa, at least 400 MPa, at least 450 MPa, at least 500 MPa, at least 550 MPa, or at least 600 MPa. CS1 and / or CS2 can be, for example, at most 1500 MPa, at most 1200 MPa, at most 900 MPa, at most 800 MPa, at most 750 MPa, at most 700 MPa, or at most 650 MPa. CS1 and / or CS2 can be, for example, in the range of 300 to 1500 MPa, 350 to 1200 MPa, 400 to 900 MPa, 450 to 800 MPa, 500 to 750 MPa, 550 to 700 MPa, or 600 to 650 MPa.

[0089] In some embodiments, CS1 and / or CS2 can be less than 600 MPa, for example, at most 550 MPa, at most 500 MPa, or at most 475 MPa. CS1 and / or CS2 can be, for example, in the range of 300 to 600 MPa, 350 to 550 MPa, 400 to 500 MPa, or 450 to 475 MPa.

[0090] The surface compressive stress CS1 on the first surface can be equal to or substantially equal to the surface compressive stress CS2 on the second surface. The absolute value of the difference CS1 - CS2 may be, for example, less than 10 MPa, at most 8 MPa, at most 5 MPa, at most 2 MPa, or at most 1 MPa.

[0091] However, the surface compressive stress CS1 on the first surface may also be substantially higher or lower than the surface compressive stress CS2 on the second surface. The absolute value of the difference CS1 - CS2 may be, for example, at least 10 MPa, at least 15 MPa, at least 20 MPa, at least 30 MPa, or at least 50 MPa. The absolute value of the difference CS1 - CS2 may be, for example, at most 100 MPa, at most 90 MPa, at most 80 MPa, at most 70 MPa, or at most 60 MPa. The absolute value of the difference CS1 - CS2 may be, for example, in the range of 10 - 100 MPa, 15 - 90 MPa, 20 - 80 MPa, 30 - 70 MPa, or 50 - 60 MPa.

[0092] The values of CS1 and / or CS2 are not necessarily constant along the entire first surface or second surface, respectively. However, it is preferable to avoid a sharp change in CS1 and / or CS2.

[0093] The overall CS variation (TCSV) of the first surface and / or the second surface of the glass member is specified as the difference between the maximum CS (CS max ) and the minimum CS (CS min ) on each surface.

[0094] The local CS variation (LCSV) of the first surface and / or the second surface is specified as the difference between the maximum CS (LCS) and the minimum CS (SCS) of the glass member along a 4 - mm measurement path on each surface. Thus, since the LCSV is given for a specific 4 - mm measurement path, there are various local CS variations LCSV i depending on the position of the measurement path on the first surface and / or the second surface of the glass member. The measurement path can be arranged on the glass member in any orientation. The various LCSV i values are for LCSVi =LCS i -SCS i (i = 1, 2, …, n (where n is the number of potentially possible 4 mm measurement paths on the first surface and / or the second surface of the glass member)) is specified. The maximum local CS variation (LCSV max ) of the first surface and / or the second surface of the glass member is the largest of all the LCSV i values of each surface of the glass member. The minimum local CS variation (LCSV min ) of the first surface and / or the second surface of the glass member is the smallest of all the LCSV i values of each surface of the glass member.

[0095] In particular, the ends of the glass member can have various geometric characteristics, for example due to a chamfered structure. Therefore, the end regions are preferably excluded from the determination of the TCSV and LCSV values. Preferably, the TCSV and / or LCSV relate to the CS values of the first surface and / or the second surface at least 0.5 mm away from the ends of the glass member. Thus, for example, the smaller thickness at the ends due to a chamfered structure is not considered for determining the minimum CS (CS min ) of the glass member. Rather, CS min is the minimum CS of the first surface and / or the second surface of the glass member at a distance of at least 0.5 mm from the ends. Similarly, the 4 mm measurement paths for determining the LCSV preferably do not include positions closer than 0.5 mm to the ends.

[0096] The first surface and the second surface of the glass member are also referred to as the two main surfaces of the glass member.

[0097] The TCSV of the first surface and / or the second surface of the glass member may be in the range of, for example, 15 to 700 MPa, 30 to 500 MPa, 50 to 300 MPa, 60 to 200 MPa, or 80 to 100 MPa. The TCSV of the first surface and / or the second surface of the glass member may be, for example, at least 15 MPa, at least 30 MPa, at least 50 MPa, at least 60 MPa, or at least 80 MPa. The TCSV of the first surface and / or the second surface of the glass member may be, for example, at most 700 MPa, at most 500 MPa, at most 300 MPa, at most 200 MPa, or at most 100 MPa.

[0098] The maximum local CS variation (LCSV max ) of the first surface and / or the second surface of the glass member over a 4 mm measurement path may be in the range of, for example, 0.1 to 50 MPa, 0.2 to 30 MPa, 0.5 to 20 MPa, 0.75 to 15 MPa, 1.0 to 10 MPa, 1.5 to 5 MPa, or 2.0 to 2.5 MPa. The LCSV max of the first surface and / or the second surface of the glass member over a 4 mm measurement path may be, for example, at least 0.1 MPa, at least 0.2 MPa, at least 0.5 MPa, at least 0.75 MPa, at least 1.0 MPa, at least 1.5 MPa, or at least 2.0 MPa. The LCSV max of the first surface and / or the second surface of the glass member over a 4 mm measurement path may be, for example, at most 50 MPa, at most 30 MPa, at most 20 MPa, at most 15 MPa, at most 10 MPa, at most 5 MPa, or at most 2.5 MPa.

[0099] The minimum local CS variation (LCSV min ) of the first surface and / or the second surface of the glass member over a 4 mm measurement path may be in the range of, for example, 0.0 to 50 MPa, 0.1 to 20 MPa, 0.2 to 10 MPa, 0.5 to 5 MPa, or 1.0 to 2.0 MPa. The LCSV minmay be, for example, 0.0 MPa. Accordingly, there may be an area of the first surface and / or the second surface of the glass member where CS does not change or substantially does not change over a measurement path of 4 mm. However, the LCSV of the first surface and / or the second surface of the glass member over a measurement path of 4 mm min may be, for example, at least 0.1 MPa, at least 0.2 MPa, at least 0.5 MPa, or at least 1.0 MPa. The LCSV of the first surface and / or the second surface of the glass member over a measurement path of 4 mm min may be, for example, at most 50 MPa, at most 20 MPa, at most 10 MPa, at most 5 MPa, or at most 2.0 MPa.

[0100] The LCSV at the first surface and / or the second surface of the glass member min / LCSV max The ratio of may be in the range of, for example, 0:1 to 1:1, 1:100 to 99:100, 1:10 to 49:50, 1:5 to 19:20, 1:2 to 9:10, 2:3 to 8:9, or 4:5 to 7:8. LCSV min / LCSV max The ratio of may be, for example, 0:1 when the first surface and / or the second surface of the glass member includes an area where CS does not change or substantially does not change over a measurement path of 4 mm. However, the LCSV min / LCSV max The ratio of may be, for example, at least 1:100, at least 1:10, at least 1:5, at least 1:2, at least 2:3, or at least 4:5. LCSV min / LCSV max The ratio may be, for example, 1:1, or essentially 1:1. LCSV min / LCSV max The closer the ratio of / LCSV is to 1:1, the more homogeneous the CS variation is over the first surface and / or the second surface of the glass member. In particular, a glass member having a wedge-shaped thickness profile may have a ratio of LCSV min / LCSV max of 1:1, or essentially 1:1. LCSV min / LCSVmax The ratio may be, for example, at most 1:1, at most 99:100, at most 49:50, at most 19:20, at most 9:10, at most 8:9, or at most 7:8. In some embodiments, LCSV min / LCSV max The ratio is particularly low, for example, at most 1:5, at most 1:10, or at most 1:100. In other embodiments, LCSV min / LCSV max The ratio is particularly high, for example, at least 9:10, at least 19:20, or at least 99:100.

[0101] CS1 and / or CS2 can also be adapted to the thickness of the glass member, and in particular can be adapted such that CS1 and / or CS2 are greater at positions where the glass member is thicker. Similarly, at positions where the glass member is thinner, CS1 and / or CS2 can be lower. The surface compressive stress at position i of the glass member, particularly a glass member having a CS value depending on the thickness, can be described as the normalized CS i as follows.

[0102]

Equation

[0103] In this equation, CS i represents the surface compressive stress (CS1 and / or CS2) at position i of the glass member. The term t i indicates the thickness of the glass member at position i. The term log 10 indicates the logarithm to the base 10 (also known as the common logarithm or decimal logarithm). CS i is expressed in MPa, and the thickness t i is expressed in μm. It is preferable that the normalized CS i is constant across the glass member. The normalized CS i =t min at and the normalized CS i at t i =t max and the normalized CS iWhen the ratio to is in the range of 0.95:1 to 1.05:1, the normalized CS of the glass member is the minimum thickness t of the glass member min at the position of and the maximum thickness t max of the normalized CS at the position i can be defined as the average of the values. For example, t i =t min of the normalized CS at i is 200 MPa, and t i =t max of the normalized CS at i is 202 MPa, the normalized CS of the glass member is defined as 201 MPa by dividing 200 MPa + 202 MPa by 2.

[0104] t i =t min of the normalized CS at i and t i =t max of the normalized CS at i is preferably in the range of 0.55:1 to 1.45:1, 0.70:1 to 1.30:1, 0.85:1 to 1.15:1, or 0.95:1 to 1.05:1.

[0105] The glass member can have a normalized CS of, for example, at least 100 MPa, at least 125 MPa, at least 150 MPa, at least 175 MPa, or at least 190 MPa. The glass member can have a normalized CS of, for example, at most 300 MPa, at most 275 MPa, at most 250 MPa, at most 225 MPa, or at most 205 MPa. The glass member can have a normalized CS in the range of, for example, 100 to 300 MPa, 125 to 275 MPa, 150 to 250 MPa, 175 to 225 MPa, or 190 to 205 MPa.

[0106] The chemically strengthened glass member of the present invention can have a first compressive stress layer extending from the first surface of the glass member to a first layer depth DoL1, and / or a second compressive stress layer extending from the second surface of the glass member to a second layer depth DoL2.

[0107] DoL1 and / or DoL2 may be, for example, at least 2.5 μm, at least 5.0 μm, at least 7.5 μm, or at least 10.0 μm. DoL1 and / or DoL2 may be, for example, at most 40.0 μm, at most 35 μm, at most 30 μm, or at most 25 μm. DoL1 and / or DoL2 may be, for example, in the range of 2.5 - 40 μm, 5.0 - 35 μm, 7.5 - 30 μm, or 10.0 - 25 μm.

[0108] DoL1 and / or DoL2 can be adapted to the thickness of the glass member. For example, DoL1 and / or DoL2 may be at least 5.0%, at least 7.5%, at least 10.0%, at least 12.5%, at least 15.0%, or at least 17.5% of the thickness of the glass member. DoL1 and / or DoL2 may be, for example, at most 40.0%, at most 35.0%, at most 30.0%, at most 27.5%, at most 25.0%, or at most 22.5% of the thickness of the glass member. DoL1 and / or DoL2 may be, for example, in the range of 5.0% - 40.0%, 7.5% - 35.0%, 10.0% - 30.0%, 12.5% - 27.5%, 15.0% - 25.0%, or 17.5% - 22.5% of the thickness of the glass member.

[0109] DoL1 and DoL2 can be equal or substantially equal. However, DoL2 may be higher or lower than DoL1. For example, the ratio of DoL2 / DoL1 or DoL1 / DoL2 may exceed 1.00, for example, at least 1.01, at least 1.02, at least 1.03, or at least 1.04. The ratio of DoL2 / DoL1 or DoL1 / DoL2 may be, for example, at most 1.20, at most 1.15, at most 1.10, at most 1.07, or at most 1.05. The ratio of DoL2 / DoL1 or DoL1 / DoL2 may be, for example, in the range of >1.00 - 1.20, 1.01 - 1.15, 1.02 - 1.10, 1.03 - 1.07, or 1.04 - 1.05.

[0110] The difference between DoL1 and DoL2 can be associated with a glass member having a specific curvature. In particular, the glass member can have a curvature where the first surface of the glass member is convex and the second surface of the glass member is concave, or vice versa. Without wishing to be bound by a particular theory, this can be at least partially explained by the difference between DoL1 and DoL2. As a result, one major surface can be "pushed" towards the center of the glass member (resulting in a concave surface), while the other major surface is "pushed" outwards (resulting in a convex surface). Generally, in the art, it is a settled idea that curvature should be avoided. However, in the present case, in some embodiments of the present invention, it has been found that a specific curvature can even be advantageous for the bendability of the member. In particular, the major surface of the glass member of the present invention facing the user of an electronic device that can be bent, such as a smartphone, can represent the inner surface of the bend (a display folded inwards). Also, as described above, generally, it is the outer surface of the bend that faces certain problems due to tensile forces. However, the problem that occurs towards the inner surface of the bend is so-called creasing. Interestingly, the convex major surface of the glass member of the present invention cancels out the problem of creasing. Thus, this makes the convex major surface even more suitable for being the inner surface of the bend.

[0111] Preferably, the glass member has at least one, more preferably exactly one, end connecting its first and second surfaces. Depending on the shape of the glass member, the end can have different sides. For example, in the case of a sheet or sheet-like glass member having a rectangle or a square, the end has four sides, where two opposite sides represent the length of the glass member and the remaining two opposite sides represent the width of the glass member. The position connecting two adjacent sides of the end is generally referred to as a corner.

[0112] The end of the glass member of the present invention may include a chamfered structure. The glass member of the present invention may have a symmetric chamfered structure or an asymmetric chamfered structure. A symmetric chamfered structure is more preferable. Schematic views of the cross-sectional profile of a glass member having a symmetric chamfered structure are shown in FIGS. 9 and 10. The chamfered structure can be best observed and described based on the cross-sectional image of the profile of the chamfered structure. To obtain such an image, the glass member is observed in transmission mode using an optical microscope. A magnification of 200 times is used. Since the focus is on the upper surface, the end portion appears very sharp. The glass member is arranged so that the upper surface does not tilt. Accordingly, the upper surface is perpendicular to the direction of light. Particularly good quality images are generally obtained using automatic white balance, automatic brightness, and automatic contrast, particularly using a Nikon Y-TV55 microscope.

[0113] The symmetry / asymmetry of the chamfered structure can be easily described in the microscope image by fitting a tangent line to the relevant surface (as shown in FIG. 10, tangent line 14a to the first connecting surface, tangent line 11a to the first surface, tangent line 13a to the third surface, tangent line 15a to the second connecting surface, and tangent line 12a to the second surface).

[0114] Fitting the tangent line to each surface can be done manually using any suitable image processing software, such as ImageJ, PowerPoint, Photoshop, etc. It is understood that those skilled in the art are well aware of more suitable software programs. Fitting the line can be easily done manually. A sufficiently accurate fit can be obtained without much effort. However, if desired, for example, fitting using the least squares method, particularly with the support of additional software, the best fit can be obtained.

[0115] In particular, the transition from one surface to another surface cannot always be specified to a particular point. In particular, the second connecting surface and / or the first connecting surface may each deviate from a straight line towards the transition to the second surface or the first surface. However, this deviation only relates to a small part of the first connecting surface and the second connecting surface. Therefore, in order to obtain a tangent to the first connecting surface with the least possible deviation of the tangent from the first connecting surface, the tangent is fitted so as to obtain the best fit towards the transition of the first connecting surface to the third surface, while a larger deviation is acceptable towards the transition of the first connecting surface to the first surface. The same applies to the fitting of the tangent to the second connecting surface.

[0116] As shown in FIG. 10, the tangent 14a to the first connecting surface intersects the tangent 11a to the first surface at a distance d from the tangent 13a to the third surface. 1 Similarly, the tangent 15a to the second connecting surface intersects the tangent 12a to the second surface at a distance d from the tangent 13a to the third surface. 2 Both d 1 and d 2 are measured perpendicular to the tangent 13a to the third surface. The lengths of the distances d 1 and d 2 can be measured in particular using any suitable image processing software, such as ImageJ, PowerPoint, Photoshop, etc. The measurement may include comparing the lengths of the distances d 1 and d 2 with the length of the scale bar respectively.

[0117] In a symmetric chamfer structure, the difference between d 1 -d 2 is relatively small or even zero.

[0118] d 1 -d 2The absolute value of the difference may be, for example, less than 30%, at most 25%, at most 20%, at most 15%, at most 10%, at most 5%, or at most 2% of the thickness of the glass member. d 1 -d 2 The absolute value of the difference may be, for example, at least 0.01%, at least 0.02%, at least 0.05%, at least 0.1%, at least 0.2%, at least 0.5%, or at least 1% of the thickness of the glass member. d 1 -d 2 The absolute value of the difference may be, for example, in the range of 0.01% to <30%, 0.02% to 25%, 0.05% to 20%, 0.1% to 15%, 0.2% to 10%, 0.5% to 5%, or 1% to 2% of the thickness of the glass member.

[0119] d 1 -d 2 The absolute value of the difference may be, for example, less than 50μm, at most 40μm, at most 30μm, at most 20μm, at most 10μm, or at most 5μm. d 1 -d 2 The absolute value of the difference may be, for example, at least 0.01μm, at least 0.02μm, at least 0.05μm, at least 0.1μm, at least 0.2μm, or at least 0.5μm. d 1 -d 2 The absolute value of the difference may be, for example, in the range of 0.01 to <50μm, 0.02 to 40μm, 0.05 to 30μm, 0.1 to 20μm, 0.2 to 10μm, or 0.5 to 5μm.

[0120] Distance d 1 and / or distance d 2 may be, for example, at least 30μm, at least 35μm, at least 40μm, at least 45μm, at least 50μm, at least 60μm, at least 70μm, at least 80μm, or at least 90μm. Distance d 1 and / or distance d 2 may be, for example, at most 1000μm, at most 750μm, at most 500μm, at most 250μm, at most 100μm, at most 90μm, at most 80μm, at most 70μm, or at most 60μm. Distance d 1and / or distance d 2 may be in the range of, for example, 30 to 1000 μm, 50 to 1000 μm, 60 to 750 μm, 70 to 500 μm, 80 to 250 μm, or 90 to 100 μm, or in the range of 30 to 100 μm, 35 to 90 μm, 40 to 80 μm, 45 to 70 μm, or 50 to 60 μm.

[0121] The present invention relates to a glass member, in particular a stack assembly comprising the glass member of the present invention, · The stack assembly is characterized in that there is no breakage when the stack assembly is held at a bending radius R of 5.0 mm at the center of the flexible region of the glass member for 60 minutes, in particular at a temperature of 25 °C and a relative humidity of 40%, and · The stack assembly comprises an index match filler having a maximum thickness of less than 20 μm, or less than 15 μm, or less than 10 μm, or less than 5 μm, and the index match filler has a refractive index n d that deviates from the refractive index n of the glass member by a maximum of 0.01 d and has, and relates to the stack assembly.

[0122] A particular advantage of the present invention is that optical distortion is avoided or at least significantly reduced by the smooth thickness transition (low LTV max ) of the present invention. This makes it possible to significantly reduce the amount of index match filler used to reduce optical distortion caused by thickness variations of the glass member in the prior art. In some embodiments, the stack assembly is even free of index match filler.

[0123] The amount of optical strain can be quantified based on a group of suitable individuals forming a test panel in an optical strain test. The inspection of the stack assembly is performed visually, and if there are visible shadows or lines or other visible defects, the members of the test panel determine that the stack assembly has optical strain. The suitable members of the test panel should not exhibit visual impairments and should be in good health. In particular, vision should not be impaired by eye infections. A test panel of at least 6 members, preferably at least 10 members, more preferably at least 15 members, and even more preferably at least 20 members is presented with the stack assembly. Each member is presented with the stack assembly independently of each other and rates the stack assembly in a "yes" or "no" manner as having optical strain or not having optical strain. If at least 80%, more preferably at least 90%, more preferably at least 95%, and more preferably 100% of the members of the panel presented with the stack assembly determine that there is no optical distortion, the stack assembly is characterized as not having optical strain.

[0124] The present invention relates to a glass member, in particular a stack assembly comprising the glass member of the present invention, · characterized in that the stack assembly has no optical distortion and · the stack assembly comprises an index match filler having a maximum thickness of less than 20 μm, or less than 15 μm, or less than 10 μm, or less than 5 μm, and the index match filler has a refractive index n d that deviates from the refractive index n of the glass member by a maximum of 0.01 d and relates also to the stack assembly.

[0125] The present invention relates to a glass member, in particular a stack assembly comprising the glass member of the present invention, · The stack assembly is characterized by having no optical distortion and / or by not being damaged when the stack assembly is held at a bending radius R of 5.0 mm at the center of the flexible region of the glass member for 60 minutes, particularly at a temperature of 25 °C and a relative humidity of 40%, and · The stack assembly includes an index matching filler with a maximum thickness of less than 20 μm, or less than 15 μm, or less than 10 μm, or less than 5 μm, and the index matching filler has a refractive index n that deviates from the refractive index n of the glass member by a maximum of 0.01, d from d to relates to the stack assembly as well.

[0126] The present invention relates to a stack assembly including a glass member, particularly a glass member of the present invention, · The stack assembly is characterized by not being damaged when repeatedly bent at a bending radius R at the center of the flexible region of the glass member 100,000 times, particularly at a temperature of 25 °C and a relative humidity of 40%. Here, for each bending axis at the bending radius R, in a width of 4.378·R (along a direction perpendicular rather than parallel to the bending axis), the glass member has an average thickness t shown by the following formula

Equation

[0127] The refractive index n of the index matching filler d is, for example, the refractive index n of the glass member dIt may deviate by up to 0.005, or up to 0.004. The refractive index n of the index matching filler d is, for example, the refractive index n of the glass member d and may deviate by at least 0.0001, at least 0.0002, or at least 0.0005. The refractive index n of the index matching filler d and the refractive index n of the glass member d The absolute value of the difference therebetween may be in the range of, for example, 0.0001 to 0.01, or 0.0002 to 0.005, or 0.0005 to 0.004.

[0128] The index matching filler may include, for example, a polymer. The index matching filler may be, for example, an optically clear resin (OCR).

[0129] Further advantages are provided by manufacturing methods including direct hot forming, cold working, and various etching techniques. Those methods can be applied as a stand-alone solution or in combination in the processing workflow.

[0130] The present invention also relates to a method for manufacturing a glass article of the present invention.

[0131] In particular, the present invention is a method for manufacturing a glass member, in particular a glass member of the present invention, comprising one or more of the following steps: · A step of hot forming via a slit down draw, particularly including a nozzle profile adapted to the thickness profile of the glass member, · A step of hot forming via an overflow down draw, particularly including an inclined overflow gutter or an overflow gutter having a height level profile adapted to the thickness profile of the glass member, · A step of hot forming via a redraw of a starting glass article adapted to the thickness profile of the glass member, · A step of hot pressing or heating a starting glass article on an inclined surface, · A step of etching a starting glass article, · mechanically grinding and / or polishing the starting glass article to a desired thickness profile relating to said method, comprising

[0132] The most cost-effective manufacturing method that results in the purest surface quality is hot forming via the down-draw technique. The method of the present invention may particularly include hot forming via slit down-draw or via overflow down-draw. Such down-draw techniques may particularly include the production of a glass ribbon from molten glass flowing out of a draw tank. Next, the glass ribbon is drawn out by a suitable roller. In particular, in the slit down-draw method, molten glass may flow out of the draw tank through a nozzle. Preferably, the glass ribbon passes through a forming region below the nozzle and / or preferably through a lehr below the forming region.

[0133] By using a slit down-draw method with a suitable specific nozzle profile and optionally appropriately adjusting the temperature profiles of the draw tank and below the draw tank, a glass ribbon with an appropriate thickness profile can be produced. In the simplest case, a wedge-shaped glass ribbon can be produced using a suitable nozzle profile and optionally a beneficial draw and / or cooling profile. A similar wedge-shaped glass ribbon can be produced using an overflow down-draw method with an inclined overflow gutter (formed body). However, generally, an asymmetric ribbon is difficult to manufacture and problems may occur due to the tension in the glass. Therefore, a more preferred approach would be to use any of the down-draw methods to produce a glass ribbon having a belly-shaped or dumbbell-shaped thickness profile (Figure 3). However, with respect to the control of the tension and warping in the glass, a glass member with a thicker central portion (belly-shaped) is easier to manufacture than a glass member with a thinner central portion (dumbbell-shaped).

[0134] The glass member may in particular have a symmetrical thickness profile, such as a bell-shaped or dumbbell-shaped thickness profile. A glass member having a symmetrical thickness profile, in particular a bell-shaped or dumbbell-shaped thickness profile, can preferably be manufactured using a slit down-draw method with an appropriate specific nozzle profile and, optionally, by correspondingly adjusting the temperature profile of the draw tank, and of the forming region below the nozzle, and / or of the lehr.

[0135] For a bell-shaped thickness profile, the nozzle profile preferably has the nozzle opening larger at the center than at the sides. The temperature profile of the draw tank can preferably be adjusted such that the temperature is higher at the center and lower at the sides. The temperature profile of the forming region and / or of the lehr can preferably be adjusted such that the cooling is higher at the center than at the sides of the glass ribbon.

[0136] For a dumbbell-shaped thickness profile, the nozzle profile preferably has the nozzle opening narrower at the center than at the sides. The temperature profile of the draw tank can preferably be adjusted such that the temperature is lower at the center and higher at the sides. The temperature profile of the forming region and / or of the lehr can preferably be adjusted such that the cooling is lower at the center than at the sides of the glass ribbon.

[0137] A ribbon having a belly-shaped or dumbbell-shaped thickness profile can be easily split in half to provide glass having a wedge-shaped thickness profile. The method may in particular include the step of cutting a glass member having a symmetric thickness profile to obtain at least two glass members having an asymmetric thickness profile, in particular a wedge-shaped thickness profile. Further, both of the above-mentioned thickness profiles can be directly used for two of the above-mentioned embodiments of the glass member, for example for a single-fold or "accordion" type display, at a suitable width. In addition to the nozzle profile and the temperature profile of the draw tank, it may be beneficial to adjust the cooling and / or heating in the forming area under the nozzle and / or in the lehr. To adjust the thickness of the glass ribbon, the cooling and / or heating in various areas of the forming area and the control of the amount of cooling or heating can be used to adjust the preferred thickness profile. Thus, heating of the area of the glass ribbon results in thinning of the ribbon in each area, while cooling preserves the thickness at specific points. For cooling, water or air coolers (direct or indirect, and aerosols of water and air) can be used, while for heating, reflective materials, air heaters, heating coils, or even laser beams can be used. In the latter case, the thickness profile can be adjusted very precisely. Such a glass ribbon having an adjusted thickness profile requires an adjusted temperature profile for cooling in the lehr in order to control the tension of the glass ribbon. The method of the present invention may in particular include cooling and / or heating in the lehr. Cooling may in particular include a water cooler, and / or an air cooler, and / or an aerosol cooler. The cooler may be direct or indirect. Heating may in particular include an air heater, a heating coil and / or a laser beam.

[0138] Other hot forming methods can include, for example, redrawing a glass ribbon from a wedge-shaped precast glass block manufactured by die casting or CNC (Computerized Numerical Control) machining, etc., creating a wedge-shaped cross-section by hot pressing or heating the glass on an inclined surface and flowing the glass under gravity. The method of the present invention can particularly include hot forming via redrawing of a starting glass article having a wedge-shaped thickness profile. The wedge-shaped thickness profile of the starting glass article can be obtained, in particular, by die casting and / or CNC machining.

[0139] In addition to the hot forming method, differential etching of thicker glass can be applied. Here, several methods can be considered. One possible method is immersion etching, where the glass is immersed in a tank filled with an etching solution and then slowly lifted out of the solution, whereby the glass surface is etched for different lengths of time, which results in a continuous wedge-shaped thickness profile if the immersion and lifting are carried out at a constant rate (Figure 4A). Another etching technique is to flow or spray the etching solution along the main surface from one end face of the glass, which induces an increase in material removal on the side where the etchant (spray or flow) hits the glass (Figure 4B). Importantly, here "side" means the end face of the glass member as shown in Figure 4B, rather than "surface". Further, coating with an etching-resistant coating (such as foil, coating, etc.) to protect parts of the surface can help create a more complex thickness profile, where various amounts of surface area can be continuously coated and a continuous thickness profile can be achieved by multiple etching steps (Figure 4C).

[0140] In other etching methods, the glass is gradually immersed in a tank filled with an etching solution, particularly at a constant rate. Thereby, the glass surface is etched for different lengths of time. When the immersion is carried out at a constant rate, this results in a continuous sawtooth-shaped thickness profile (Figure 11). The terms "immersion rate" and "speed of immersion" are used interchangeably in this application and, unless otherwise indicated, preferably relate to the average immersion rate. The immersion rate is preferably in the range of 1 mm / min to 50 mm / min, such as 2 mm / min to 25 mm / min, 4 mm / min to 15 mm / min, or 6 mm / min to 10 mm / min. The immersion rate may preferably be at least 1 mm / min, more preferably at least 2 mm / min, more preferably at least 4 mm / min, more preferably at least 6 mm / min. The immersion rate may preferably be at most 50 mm / min, more preferably at most 25 mm / min, more preferably at most 15 mm / min, more preferably at most 10 mm / min.

[0141] The immersion rate is preferably constant. This is advantageous for achieving a very constant LTV max Preferably, the ratio of the maximum immersion rate to the minimum immersion rate is at most 1.25:1, more preferably at most 1.10:1, more preferably at most 1.05:1, more preferably at most 1.02:1, more preferably at most 1.01:1.

[0142] The immersion rate can also be adapted to the etching rate or the thickness reduction rate, respectively. The etching rate is generally expressed in the unit of "μm per minute per side". The term "per side" relates to the fact that the glass member has two sides, namely the first surface and the second surface. Therefore, in order to describe the thickness reduction rate due to the etching process, the etching rate "per side" must be multiplied by 2 because there are two sides. For example, when the etching rate is 1 μm per minute per side, the thickness reduction rate of the glass member is 2 μm per minute. The thickness reduction rate indicates the thickness reduction rate of the glass article or glass member during exposure to the etching solution. For example, when the thickness reduction rate is 2 μm per minute, the thickness of the glass article or glass member is reduced by 2 μm per minute during exposure to the etching solution.

[0143] Preferably, the ratio of the immersion rate (mm per minute) to the thickness reduction rate (μm per minute) is in the range of 500:1 to 50,000:1, such as 1,000:1 to 25,000:1, or 2,000:1 to 10,000:1. The ratio of the immersion rate to the thickness reduction rate is preferably at least 500:1, more preferably at least 1,000:1, and even more preferably at least 2,000:1. The ratio of the immersion rate to the thickness reduction rate is preferably at most 50,000:1, more preferably at most 25,000:1, and even more preferably at most 10,000:1.

[0144] A preferred etching solution is HF and / or HNO 3It includes. The etching rate is preferably 0.1 to 10.0 μm per minute per side, for example 0.2 to 5.0 μm per minute per side, or 0.5 to 2.0 μm per minute per side. The etching rate is preferably at least 0.1 μm per minute per side, more preferably at least 0.2 μm per minute per side, and even more preferably at least 0.5 μm per minute per side. The etching rate is preferably at most 10.0 μm per minute per side, more preferably at most 5.0 μm per minute per side, and even more preferably at most 2.0 μm per minute per side.

[0145] The thickness reduction rate is preferably 0.2 to 20.0 μm per minute, for example 0.5 to 10.0 μm per minute, or 1.0 to 5.0 μm per minute. The thickness reduction rate is preferably at least 0.2 μm per minute, more preferably at least 0.5 μm per minute, and even more preferably at least 1.0 μm per minute. The thickness reduction rate is preferably at most 20.0 μm per minute, more preferably at most 10.0 μm per minute, and even more preferably at most 5.0 μm per minute.

[0146] The above glass member can also be manufactured by mechanical grinding or polishing (Figure 5A). However, in the thickness range required for such a foldable glass member, angled grinding or polishing can be extremely difficult. A combination of mechanical processing techniques and chemical processing techniques can be a solution. Therefore, a desired thickness profile can be introduced into a thicker glass sheet by mechanical abrasion, and the glass can then be thinned to the target thickness by subsequent chemical etching (Figures 5B and 5C). Thereby, the etching process can be performed uniformly throughout the glass body (for example, overall etching as shown in Figure 5C), or applied only to one or more surfaces by protecting other surfaces with a coating of each etching resistance (for example, as shown in Figure 5B).

[0147] The method of the present invention can in particular include the etching of the starting glass article, said etching being one or more of the following: · Repeatedly immersing the starting glass article in an etching solution, removing it from the etching solution and performing immersion etching; · Flowing or spraying an etching solution along the first surface and / or the second surface of the glass article from one end of the starting glass article; · Coating a portion of the first surface and / or the second surface of the starting glass article, subsequently bringing the starting glass article into contact with the etching solution, and the coating preventing or reducing etching removal from the coated surface portion; and includes.

[0148] The coating can in particular include a foil and / or a coating.

[0149] The method of the present invention can in particular include mechanical grinding or polishing, in particular before the etching step.

[0150] In addition to the above examples, further developments of the manufacturing method can include combinations of the above hot forming, cold working and etching techniques. Thus, in some embodiments of the display, it may be beneficial to protect one or more surfaces of the glass from the etching solution, thereby preserving the flame-polished surface in its pure state. Such glass members can provide excellent surface quality and increased bending strength.

[0151] A further advantage of the wedge-shaped glass member produced by hot forming is that in a conventional stacking process, such wedges can be bonded together in alternately opposing directions, in which case an adhesive layer of uniform / constant thickness can be used, and such a stack of glass does not tilt in one or the other direction, thus facilitating handling and processing.

[0152] Furthermore, the above-described glass member can be subjected to a conventional chemical strengthening method to further improve its impact resistance and / or bending properties. Accordingly, the method may particularly include a step of chemically strengthening the glass member by ion exchange.

[0153] The present invention also relates to a bendable device including the glass member and / or stack assembly of the present invention. The bendable device can be bent, for example, at a bending radius of 1 to 5 mm without breakage, particularly for 60 minutes, at a temperature of 25 °C and a relative humidity of 40%. The bendable device may be, for example, an electronic device, particularly a smartphone.

[0154] The present invention also relates to the use of the glass member and / or stack assembly of the present invention in foldable consumer electronic devices, such as mobile phones, tablets, computers, particularly laptops, and / or on the screens of monitors or TVs.

Brief Description of the Drawings

[0155]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

[0156] Description of the Drawings FIG. 1 schematically shows glass members according to various embodiments of the present invention.

[0157] FIGS. 1A, 1B and 1C schematically show cross sections of glass members having various thickness profiles of the present invention. FIG. 1A shows a glass member having a wedge-shaped thickness profile. FIG. 1B shows a glass member having a thickness profile having a thicker central region and two thinner outer regions. FIG. 1C shows a glass member having a thickness profile having a wavy contour on one surface.

[0158] FIGS. 1D, 1E and 1F schematically show the glass members of FIGS. 1A, 1B and 1C, respectively, in a possible folded state. For simplicity of illustration, the thickness profiles are omitted in the illustrations of FIGS. 1D, 1E and 1F.

[0159] The embodiments of FIGS. 1A and 1D can employ, for example, an S-fold or a G-fold. The embodiments of FIGS. 1B and 1E can employ, for example, a so-called "accordion fold". The embodiments of FIGS. 1C and 1F allow for multiple folds.

[0160] FIG. 2 schematically shows another embodiment in which the glass member can be wound up on one side while the other side remains straight or can be further bent.

[0161] FIG. 3 schematically shows a method for manufacturing the glass member of the present invention by hot forming through a slit down draw. FIG. 3 shows a slit down draw device 31 for manufacturing a glass ribbon 32 whose dimensions are schematically shown by dotted lines. In FIGS. 3A and 3B, the slit down draw device differs in the shape of the nozzle, which is dumbbell-shaped in FIG. 3A and belly-shaped in FIG. 3B. The differently shaped nozzles of the slit down device 31 result in differently shaped glass members 33a. The glass member 33a has a dumbbell-shaped thickness profile in FIG. 3A and a belly-shaped thickness profile in FIG. 3B, respectively. By cutting the glass member 33a (schematically shown by scissors in FIG. 3), a glass member 33b having an asymmetric thickness profile, for example, a wedge-shaped thickness profile, can be obtained.

[0162] FIG. 4 schematically shows an etching technique that can be applied to obtain the glass member of the present invention.

[0163] FIG. 4A shows a glass article 41a that is repeatedly immersed in and taken out of an etching solution contained in a container 42a as shown by the arrows. The repeated immersion and taking out result in a glass member 41b having a wedge-shaped thickness profile. By using further immersion and taking out, a glass member 41c having a more prominent wedge-shaped thickness profile can be obtained.

[0164] FIG. 4B schematically shows the flow of the etching solution (indicated by the arrows) from one end face of the glass member 41d, along the first surface and along the second surface of the glass member 41d within the container 42b. Since the flow of the etching solution leads to an increase in the removal of material from one end face of the glass member 41d, a wedge-shaped thickness profile is produced.

[0165] FIG. 4C schematically shows the glass members 41e and 41f disposed in the etching solution within the container 42c. The surfaces of the glass members are protected from the etching solution to various degrees by various coatings (such as coatings or foils) indicated by elongated rectangles filled with a striped pattern. Based on the arrangement of the coatings, complex thickness profiles, such as the wedge-shaped thickness profile 41e of the glass member or the inclined thickness profile 41f of the glass member, can be generated.

[0166] FIG. 5A schematically shows the manufacture of the glass member 52a having the thickness profile of the present invention using the CNC instrument 51. FIGS. 5B and 5C show that the thickness profile of the glass member can be further modified by etching as indicated by the arrows. The original thickness profile is indicated by the dotted line. The etching process results in the removal of further material, leading to the glass members 52b and 52c whose thickness profiles are indicated by the solid lines respectively.

[0167] FIG. 6 schematically shows a cross-section of the glass member of the present invention having a wedge-shaped thickness profile.

[0168] As shown in FIG. 6A, the glass member has at least a first flexible region characterized by no breakage when held around the bending axis B 1 with a first bending radius R 1 for 60 minutes, and a second flexible region characterized by no breakage when held around the bending axis B 2 with a second bending radius R 2It may include at least a second flexible region characterized by no breakage when held. The bending axes of the first flexible region and the second flexible region are each dashed line B 1 and B 2 as indicated. The width of the flexible region (indicated by the distance of the dotted line) is 4.378·R 1 and 4.378·R 2 respectively along the direction perpendicular to the bending axes B 1 and B 2 defined as.

[0169] As shown in FIG. 6B, the glass member has a minimum thickness t min and a maximum thickness t max . The glass member has a thickness t 1 at the position of the first bending axis B 1 , and a thickness t 2 at the position of the second bending axis B 2 . Within the width of the flexible region of 4.378·R (along the direction perpendicular rather than parallel to the bending axis), the glass member preferably has an average thickness t

Equation

[0170] In the glass member shown in FIG. 6B, the average thickness t avg in the flexible region corresponds to the thickness t 1 at the bending axis B 1 of the first flexible region and the thickness t 2 at the bending axis B 2 of the second flexible region in view of the wedge-shaped thickness profile of the glass member. Therefore,

Equation

[0171] For example, when the Young's modulus E of the glass is about 70 GPa and the bending radius R is 1.5 mm 1 and the bending radius R is 5.0 mm 2 is desired, t 1 should be at most about 54 μm, and t 2 should be at most about 179 μm.

[0172] The following table summarizes the dimensions of the glass members of the present invention that meet those requirements, based on the wedge-shaped thickness profile as shown in FIG. 6B.

[0173]

Table 2

[0174] In particular, such a glass member may even have a thickness t 2 that is small enough to satisfy the above equation at a bending radius R of 3.0 mm 2 even.

[0175] Glass members having the thickness and distance values shown in the table are particularly preferred because they provide a uniform thickness profile that results in a constant LTV along the glass member. For example, the thickness variation from t min to t 1 is 24 μm over a length of 60 mm. This corresponds to a thickness variation of 0.4 μm per mm, or equivalently, an LTV of 1.6 μm over a measurement path of 4 mm. Similarly, the thickness variation from t 2 to t max is 24 μm over a length of 60 mm, corresponding to a thickness variation of 0.4 μm per mm, or equivalently, an LTV of 1.6 μm over a measurement path of 4 mm. The thickness variation from t 1 to t 2 is 33 μm over a length of 80 mm, and similarly corresponds to a thickness variation of 0.4 μm per mm, or equivalently, an LTV of 1.6 μm over a measurement path of 4 mm. Therefore, the local thickness variation is uniform across the glass member, and the ratio of LTV min / LTV max is 1:1.

[0176] Minimum thickness t min position of and maximum thickness t max distance d between the positions of total is, in particular, except for a safety distance of 0.5 mm from the end to be observed in the specification of t min and t max and can correspond to the length or width of the glass member, excluding the chamfer structure, etc., at the end

[0177] Figure 7 is a non - to - scale schematic view of the setup of the ball - on - ring test. Figure 7A shows the top / bottom view of the setup. Figure 7B shows the cross - sectional view of the setup. In the ball - on - ring test, the surface 75 of the glass member 71 is placed on a steel ring 72 having an inner diameter of 4 mm and an outer diameter of 6 mm. The ring has a depth of 3 mm, the wall of the ring is 1 mm thick, and the tip of the wall has a semi - circle with a diameter of 1 mm as a cross - section. A tungsten carbide ball 73 having a diameter of 1 mm is pressed against the surface 74 of the glass member 71 along the central axis of the ring at a speed of 5 mm / min until the glass is crushed. The force at the time of fracture is recorded as the ball - on - ring fracture force.

[0178] Figure 8 is an image obtained by an interferometer (Verifire (registered trademark), manufactured by Zygo) of the wedge - shaped glass member of the present invention having a width of 71 mm and a length of 156 mm. The evenly distributed contour lines indicate a smooth thickness change from one end to the other. The thickness is constant along each specific line. The minimum thickness t min is 32 μm, the maximum thickness t max is 69 μm, and the overall thickness variation of 37 μm specified as t max -t min is obtained. The maximum local thickness variation (LTV max ) over a measurement path of 4 mm was about 0.95 μm. The ratio of LTV min / LTV max was essentially 1:1.

[0179] FIG. 9 schematically shows a profile of a glass member 10 including a first surface 11, a second surface 12, and at least one end portion connecting the first surface 11 and the second surface 12. In the view of FIG. 9, the first surface 11 and the second surface 12 appear to be essentially parallel to each other. However, this is mainly done to simplify the view. For example, in a wedge-shaped glass member, such a cross-sectional profile can be observed when looking at the side facing the side with the maximum thickness or the side facing the side with the minimum thickness. When facing one of the other sides, as shown in FIGS. 1A and 6 for example, it is shown that the first and second surfaces of the wedge-shaped glass member are not parallel to each other. In the view of FIG. 9, the end portion has a chamfered structure 16 including three surfaces, namely (i) a third surface 13, (ii) a first connecting surface 14 connecting the third surface 13 and the first surface 11, and (iii) a second connecting surface 15 connecting the third surface 13 and the second surface 12. The chamfered structure 16 of the glass member 10 shown in FIG. 9 is symmetric.

[0180] Figure 10 schematically shows a preferred method for identifying the symmetry / asymmetry of the chamfer structure. In the display of Figure 10, the first surface 11 and the second surface 12 are shown essentially parallel to each other. However, as discussed above with respect to Figure 9, this is mainly done to simplify the display. The display in Figure 10 can be used in particular to identify the symmetry / asymmetry of the chamfer structure based on a microscopic image of a cross-section of the glass member. The tangents to the relevant surfaces are shown as dotted lines (tangent 14a is for the first connecting surface, tangent 11a is for the first surface, tangent 13a is for the third surface, tangent 15a is for the second connecting surface, and tangent 12a is for the second surface). The fitting of the tangents to each surface can be done manually, for example using ImageJ software (e.g., version 1.53i of March 24, 2021). In particular, the second connecting surface, and / or the first connecting surface, may deviate from a straight line towards the transition to the second surface or the first surface respectively. Thus, while the tangent should be fitted so as to obtain the best fit towards the transition of the first connecting surface to the third surface, a larger deviation can be acceptable towards the transition of the first connecting surface to the first surface. The same applies mutatis mutandis to the fitting of the tangent to the second connecting surface. As shown in Figure 10, the tangent 14a to the first connecting surface intersects the tangent 11a to the first surface at a distance d 1 from the tangent 13a to the third surface. Similarly, the tangent 15a to the second connecting surface intersects the tangent 12a to the second surface at a distance d 2 from the tangent 13a to the third surface. Both d 1 and d 2 are measured perpendicular to the tangent 13a to the third surface, for example using ImageJ software. The measurement can be done in particular by comparing the lengths of d 1 and d 2 with the length of the scale bar respectively.

[0181] Figure 11 schematically shows another etching technique that can be applied to obtain the glass member of the present invention. The starting glass article 80a is gradually immersed at a constant rate into an etching solution contained within a container 81, as indicated by the arrow. The gradual immersion first results in an intermediate glass article 80b and ultimately in a final glass member 80c having a wedge-shaped thickness profile. The starting glass article 80a does not have a wedge-shaped thickness profile. The intermediate glass article 80b includes a portion having a wedge-shaped thickness profile (the portion already immersed in the etching solution) and a portion not having a wedge-shaped thickness profile (the portion not yet immersed in the etching solution). The final glass member 80c has a wedge-shaped thickness profile over its entire length.

Example

[0182] As schematically shown in FIG. 11, a glass member having a wedge-shaped thickness profile was obtained by gradually immersing it into the etching solution at a constant rate of about 8 mm per minute. The etching solution contained HF and HNO 3 The etching rate was about 1 μm per minute per side, which corresponds to a thickness reduction of about 2 μm per minute.

[0183] Prior to the etching step, the starting glass article had a thickness of 70 μm, a width of 71 mm, and a length of 156 mm. By gradually immersing the glass member into the etching solution, the glass surface was etched for different lengths of time. One end of the glass member had already been in the etching solution for a time calculated by dividing 156 mm by 8 mm per minute, i.e., 19.5 minutes, by the time the opposite end of the glass member was immersed in the etching solution. Thus, based on a thickness reduction of about 2 μm per minute, it can be calculated that the thickness at one end of the glass member should have decreased by about 2 μm × 19.5 minutes, i.e., 39 μm. Thus, the predicted TTV is 39 μm. This estimated value is very close to the actual data based on measurements of the thickness of the glass member at various positions using a micrometer. The minimum thickness t minwas at one end of the glass member and was 32 μm. The maximum thickness t max was at the opposite end of the glass member and was 69 μm. Therefore, the TTV was 37 μm.

[0184] The local thickness variation (LTV) was constant along the length of the glass member, as shown in FIG. 8. The LTV min / LTV max ratio was essentially 1:1. The evenly distributed contour lines in FIG. 8 indicate a smooth change in thickness from one end to the other. The thickness is constant along each specific line.

[0185] In view of the wedge-shaped thickness profile having a constant thickness variation along the length of the glass member, LTV max =LTV min =TTV / length = 37 μm / 156 mm can be calculated, which is about 0.95 μm over a measurement path of 4 mm.

Explanation of Signs

[0186] 10 Glass member 11 First surface 11a Tangent to the first surface 12 Second surface 12a Tangent to the second surface 13 Third surface 13a Tangent to the third surface 14 First connection surface 14a Tangent to the first connection surface 15 Second connection surface 15a Tangent to the second connection surface 16 Chamfer structure 31 Slit down-draw device 32 Glass ribbon 33a, 33b Glass members 41a~41f Glass members 42a, 42b Containers 51 CNC tool 52a~52c Glass members 71 Glass member 72 Steel ring 73 Tungsten carbide ball 74 Surface 75 Surface 80a Starting glass article 80b Intermediate glass article 80c Wedge-shaped glass member 81 Container

Claims

1. A glass member having a first surface and a second surface, having the following thickness profile: ・ The glass member has a minimum thickness t min and a maximum thickness t max where t min is at least 10 μm and t max is at most 400 μm, - The total thickness variation (TTV) of the glass member is in the range of 10 μm to 390 μm, and ・ The maximum local thickness variation (LTV max ) of the glass member over a measurement path of 4 mm is at most 69 µm characterized by the above, the glass member.

2. The glass member according to claim 1, wherein the TTV of the glass member is at least 30 μm.

3. t min The glass member according to claim 1 or 2, wherein t is at most 100 μm, preferably at most 70 μm.

4. t max The glass member according to any one of claims 1 to 3, wherein t is at least 60 μm, preferably at least 70 μm.

5. t max The glass member according to any one of claims 1 to 4, wherein t is at most 150 µm.

6. t max / t min The glass member according to any one of claims 1 to 5, wherein the ratio of max / min is in the range of 3:2 to 40:

1.

7. t max / t min The glass member according to any one of claims 1 to 6, wherein the ratio of

8. The maximum local thickness variation (LTV max ) of the glass member over a measurement path of 4 mm is at most 5 μm, the glass member according to any one of claims 1 to 7.

9. LTV max The glass member according to any one of claims 1 to 8, wherein the ratio of / TTV is in the range of 0.1% to 50.0%.

10. The minimum local thickness variation (LTV min ) of the glass member over a measurement path of 4 mm is at least 0.1 μm, the glass member according to any one of claims 1 to 9.

11. LTV min / LTV max The glass member according to any one of claims 1 to 10, wherein the ratio of min / max is in the range of 1:50 to 1:

1.

12. The glass member according to any one of claims 1 to 11, wherein the glass member has a length in the range of 10 mm to 500 mm and / or a width in the range of 5 mm to 400 mm, and the ratio of the length to the width is at least 1:

1.

13. The glass member according to any one of claims 1 to 12, wherein the glass member has a wedge-shaped thickness profile.

14. The surface roughness R on the first surface and / or the second surface a The glass member according to any one of claims 1 to 13, wherein the surface roughness R is at most 0.80 nm.

15. The glass article according to any one of claims 1 to 14, wherein the glass member includes at least one impact-resistant region characterized by an impact resistance corresponding to a normalized pen drop height of at least 2.0 per 1 μm.

16. The glass article according to any one of claims 1 to 15, wherein the glass member includes at least one impact-resistant region characterized by an impact resistance corresponding to a pen drop height of at least 5 mm.

17. The glass article according to any one of claims 1 to 16, wherein the glass member includes at least one flexible region characterized by a ball-on-ring breaking force of at least 5.0 N and / or a two-point bending strength of at least 1300 MPa.

18. The glass member according to claim 17, wherein the glass member includes at least two flexible regions.

19. The glass member according to any one of claims 1 to 18, wherein the glass member includes at least one flexible region characterized by no breakage when the glass member is held at a bending radius R of 5.0 mm at the center of the flexible region for 60 minutes.

20. The glass member according to any one of claims 1 to 19, characterized in that the glass member comprises at least one flexible region characterized by no breakage when the glass member is held at a bending radius R of 1.5 mm at the center of the flexible region for 60 minutes.

21. The glass member, ・ When the glass member is held at a first bending radius R of 1.5 mm at the center of the first flexible region for 60 minutes 1 at least a first flexible region characterized by no breakage, and ・ The glass member is characterized by no breakage when held at a second bending radius R of 5.0 mm at the center of the second flexible region for 60 minutes 2 at least a second flexible region characterized by no breakage when held at a second bending radius R of 5.0 mm at the center of the second flexible region for 60 minutes comprising the glass member according to any one of claims 1 to 20.

22. The width of the flexible region is defined as 4.378·R along a direction perpendicular to the bending axis forming the center of the flexible region, and the average thickness t of the glass member across the width of the flexible region avg is as follows 【Number 1】 where R is the bending radius and E is the Young's modulus of the glass, the glass member according to any one of claims 19 to 21.

23. The glass member according to any one of claims 1 to 22, wherein the glass member has a warp of 5 mm or less.

24. The glass member is 1 mm 2 The glass member according to any one of claims 1 to 23, having an area relative warp in the range of 1 nm to 5.0 µm per

25. The glass member according to any one of claims 1 to 24, wherein the glass member has a length relative warp in the range of 1 nm to 50.0 μm per 1 mm.

26. The glass comprises the following components: Component Ratio (mass%) SiO 2 45 to 75 Al 2 O 3 2.5 to 25 Li 2 O 0 to 10 Na 2 O 5 to 20 K 2 O 0 to 10 MgO 0 - 15 CaO 0 - 10 P 2 O 5 0 to 20 BaO 0 - 5 ZnO 0 - 5 ZrO 2 0 to 5 B 2 O 3 0 to 10 TiO 2 0 to 5 The glass member according to any one of claims 1 to 25, containing the indicated amounts (mass%).

27. The glass member according to any one of claims 1 to 26, wherein the Young's modulus E of the glass is in the range of 60 to 80 GPa.

28. The glass member includes at least one end portion connecting the first surface and the second surface, ・ The end portion has the following three surfaces: - A third surface, - A first connecting surface connecting the third surface and the first surface, and - A second connecting surface connecting the third surface and the second surface having a chamfered structure, ・ The chamfered structure - The tangent line A to the first connection surface intersects the tangent line B to the first surface at a location where it is at a distance d from the tangent line C to the third surface, and 1 where it intersects the tangent line B to the first surface, and - The tangent D to the second connection surface intersects the tangent E to the second surface at a distance d from the tangent C to the third surface 2 where the tangent E to the second surface intersects it has a profile, where -d 1 and d 2 both are measured perpendicular to the tangent line C to the third surface, - The tangents A to E are obtained by fitting the respective tangents to the corresponding surfaces in the profile of the chamfered structure. The glass member according to any one of claims 1 to 27.

29. difference d 1 -d 2 The glass member according to claim 28, wherein an absolute value of is less than 30% of a thickness of the glass member.

30. difference d 1 -d 2 The glass member according to claim 28 or 29, wherein the absolute value of is less than 50 μm.

31. d 1 and / or d 2 The glass member according to any one of claims 28 to 30, wherein d is in the range of 30 to 1000 μm.

32. The glass member according to any one of claims 1 to 31, wherein the glass member is chemically strengthened.

33. The glass member according to claim 32, wherein each of the surface compressive stress CS1 at the first surface of the glass member and the surface compressive stress CS2 at the second surface of the glass member is at least 300 MPa and / or at most 1500 MPa.

34. The member has a first compressive stress layer extending from the first surface of the glass member to a first layer depth DoL1 and a second compressive stress layer extending from the second surface to a second layer depth DoL2, and each of DoL1 and DoL2 is in the range of 2.5 to 40.0 μm. The glass member according to claim 32 or 33.

35. The surface compressive stress at the position i of the glass member is the normalized CS i is expressed by the following formula 【Number 2】 described based on this, where CS i represents the surface compressive stress (CS1 and / or CS2) at the position i of the glass member, and t i and the term indicates the thickness of the glass member at the position i, and log 10 and the term indicates the logarithm with base 10, CS i is expressed in MPa, and the thickness t i is expressed in μm, and t i = t min the normalized CS at i and t i = t max the normalized CS at i and the ratio of is in the range of 0.55:1 to 1.45:1, The glass member according to any one of claims 32 to 34.

36. The normalized CS of the glass member is the normalized CS at the position of the minimum thickness t of the glass member min and the normalized CS at the position of the maximum thickness t i is defined as the average of the value and the normalized CS at the position of the maximum thickness t max and the normalized CS ranges from 100 to 300 MPa, the glass member according to claim 35 i wherein the normalized CS is in the range of 100 to 300 MPa

37. A stack assembly including a glass member, particularly the glass member according to any one of claims 1 to 36, ・ The stack assembly is characterized by having no optical distortion and / or by not being damaged when the stack assembly is held at a bending radius R of 5.0 mm at the center of the flexible region of the glass member for 60 minutes, and - The stack assembly includes an index matching filler having a maximum thickness of less than 20 μm, and the index matching filler has a refractive index n d that deviates from the refractive index n d of the glass member by a maximum of 0.

01. The stack assembly.

38. The refractive index n of the index matching filler d is within a maximum deviation of 0.004 from the refractive index n d of the glass member, the stack assembly according to claim 37.

39. The stack assembly according to claim 37 or 38, wherein the index matching filler includes a polymer.

40. The stack assembly is characterized by not being damaged when the stack assembly is repeatedly bent at a bending radius R at the center of the flexible region of the glass member 100,000 times, particularly at a temperature of 25 ° C and a relative humidity of 40%. For each bending axis at the bending radius R, at a width of 4.378·R (along a direction perpendicular to, not parallel to, the bending axis), the glass member satisfies the following formula [Number 3] The average thickness t shown in avg having, where E is the Young's modulus of the glass, The stack assembly according to any one of claims 37 to 39.

41. A method for manufacturing the glass member according to any one of claims 1 to 36, including one or more of the following steps: ・ In particular, a step of hot-forming a glass melt through a slit down-draw including a nozzle profile adapted to the thickness profile of the glass member, ・ In particular, a step of hot-forming a glass melt through an overflow down-draw including an inclined overflow gutter or an overflow gutter having a height level profile adapted to the thickness profile of the glass member, ・ A step of hot-forming through a redraw of a starting glass article adapted to the thickness profile of the glass member, ・ A step of hot-pressing or heating a starting glass article on an inclined surface, ・ A step of etching a starting glass article to obtain a desired thickness profile, - mechanically grinding and / or polishing the starting glass article to a desired thickness profile The method as described above. **Claim 42** The method according to claim 41, comprising hot forming via a slit down-draw or via an overflow down-draw. **Claim 43** The method according to claim 41 or 42, wherein the method comprises hot forming via a slit down-draw, a glass ribbon being produced from the molten glass flowing out from the draw tank through the nozzle, the glass ribbon passing through a forming region below the nozzle, and passing through a lehr below the forming region. **Claim 44** The method according to any one of claims 41 to 43, wherein the glass member has a symmetric thickness profile, in particular a belly-shaped or dumbbell-shaped thickness profile. **Claim 45** The method according to claim 44, further comprising cutting a glass member having a symmetric thickness profile to obtain at least two glass members having an asymmetric thickness profile, in particular a wedge-shaped thickness profile. **Claim 46** The method according to any one of claims 43 to 45, wherein the temperature profile of the draw tank is adjusted such that the temperature of the draw tank is higher in the center and lower at the sides, or the temperature of the draw tank is lower in the center and higher at the sides. **Claim 47** The method according to any one of claims 43 to 46, comprising cooling and / or heating in the forming region below the nozzle and / or in the lehr. **Claim 48** The method according to any one of claims 43 to 47, comprising cooling in the forming region below the nozzle and / or in the lehr, wherein the cooling is higher at the center of the ribbon than at the sides, or the cooling is higher at the sides of the ribbon than at the center. **Claim 49** The method according to claim 47 or 48, wherein the cooling comprises a water cooler and / or an air cooler and / or an aerosol cooler, and the cooler is direct or indirect. **Claim 50** The method according to any one of claims 47 to 49, wherein the heating comprises a reflective material, an air heater, a heating coil, and / or a laser beam. **Claim 51** The method according to claim 41, wherein the method includes hot forming through redrawing of a starting glass article, and the starting glass article has a wedge-shaped thickness profile.

52. The method according to claim 51, wherein the wedge-shaped thickness profile of the starting glass article is obtained by die casting and / or CNC (Computerized Numerical Control) machining.

53. The method according to any one of claims 41 to 52, wherein the method includes etching of a starting glass article, and the etching includes one or more of the following: - Repeatedly immersing the starting glass article in an etching solution, removing it from the etching solution, and performing immersion etching; - Flowing or spraying an etching solution along the first surface and / or the second surface of the glass article from one end of the starting glass article; - Coating a portion of the first surface and / or the second surface of the starting glass article, and subsequently bringing the starting glass article into contact with the etching solution, wherein the coating prevents or reduces etching removal from the coated surface portion. The method according to any one of claims 41 to 52.

54. The method according to any one of claims 41 to 52, wherein the method includes etching a starting glass article, and the etching includes gradually immersing the starting glass article in a tank filled with an etching solution, particularly at a constant immersion rate.

55. The method according to claim 54, wherein the average immersion rate is in the range of 1 mm / min to 50 mm / min.

56. The method according to claim 54 or 55, wherein the ratio of the maximum immersion rate to the minimum immersion rate is at most 1.25:

1.

57. The method according to any one of claims 54 to 56, wherein the ratio of the immersion rate (mm per minute) to the thickness reduction rate (μm per minute) is in the range of 500:1 to 50,000:

1.

58. The etching solution contains HF and / or HNO 3 The method according to any one of claims 53 to 57.

59. The method according to any one of claims 53 to 58, wherein the etching rate is in the range of 0.1 to 10.0 μm per minute per side.

60. The method according to any one of claims 53 to 59, wherein the thickness reduction rate is in the range of 0.2 to 20.0 μm per minute.

61. The method according to claim 53, wherein the coating includes a foil and / or a coating.

62. The method according to any one of claims 41 to 61, wherein the method includes mechanical grinding and / or polishing, particularly before the etching step.

63. The method according to any one of claims 41 to 62, wherein the method further includes a step of chemically strengthening the glass member, particularly by ion exchange.

64. A device capable of being bent, comprising the glass member according to any one of claims 1 to 36 or the stack assembly according to any one of claims 37 to 40.

65. The device capable of being bent according to claim 64, wherein the device can be bent to a bending radius of 1 mm to 5 mm.

66. The device capable of being bent according to claim 64 or 65, wherein the device is an electronic device, particularly a smartphone.

67. Use of the glass member according to any one of claims 1 to 36 or use of the stack assembly according to any one of claims 37 to 40 in a foldable consumer electronic device, such as a mobile phone, a tablet, a computer, particularly a laptop, and / or in a screen of a monitor or a television.

Images