Glass articles with improved surface quality

Abstract

A glass article having a thickness of 10 μm to 150 μm, comprising a first surface, a second surface, and at least one end portion, the end portion having a chamfer structure including three surfaces: a vertical surface, a first connecting surface, and a second connecting surface, the chamfer structure having a profile in which a tangent A to the first connecting surface intersects a tangent B to the first surface at a distance d1 from a tangent C to the vertical surface, and a tangent D to the second connecting surface intersects a tangent E to the second surface at a distance d2 from a tangent C to the vertical surface, the chamfer structure being asymmetric such that d1 ≠ d2. And a method for manufacturing the glass article.

Description

[Technical Field]

[0001] The present invention relates to glass articles having improved surface quality, and to a method for manufacturing glass articles. [Background technology]

[0002] Ultra-thin glass (UTG) has great potential in a variety of applications, such as consumer electronics and optical devices. In particular, given its flexibility, UTG is advantageous for flexible displays in smartphones, for example.

[0003] Manufacturing UTG at various ultra-thin target thicknesses is technically challenging. The conventional approach is to manufacture the glass article at a thicker thickness, particularly by downdraw or overflow fusion methods, and then introduce a slimming process to reach the target thickness.

[0004] Due to its thinness and brittleness, the most conventionally applied processing method is stacking. In stacking, a stack assembly is formed, comprising multiple glass articles and at least one adhesive layer between two adjacent glass articles. Such a stack assembly is then processed in several stacking steps, such as cutting to a desired article size, grinding the edges, and / or etching to obtain a chamfered edge structure.

[0005] However, the aforementioned slimming process to achieve the target thickness is applied after delayering the stack assembly. This is because, for slimming to occur, the etching solution applied for slimming must come into contact with the main surface of the glass articles. The main surface of the glass articles is protected from the etching solution by an adhesive layer that connects articles within the stack assembly to adjacent articles. Therefore, the stack assembly is first delayered by removing the adhesive layer, and then the individualized glass articles are subjected to the slimming process in the etching solution to obtain the desired UTG articles.

[0006] A drawback of the slimming process is that it results in a compromised surface quality compared to the original surface quality of the glass article obtained by downdrawing. The downdrawing method results in a glass article where both main surfaces are flame-polished. Flame-polished surfaces are characterized by particularly low surface roughness. Furthermore, flame-polished surfaces are advantageous because they have fewer surface defects. The surface quality of flame-polished surfaces is extremely good. Good surface quality is particularly advantageous with respect to bending properties. Surface defects can lead to a substantial decrease in bending strength. This is especially true for surface defects on the glass surface on the outside of the bend, which are subjected to tensile stress during bending.

[0007] UTG with improved bending strength is required.

[0008] Furthermore, UTG should meet other criteria in addition to its flexibility. In particular, UTG should be able to withstand the mechanical shocks that commonly occur during use in electronic devices, such as smartphones. High shock resistance is advantageous.

[0009] Interestingly, particularly in bendable electronic devices such as smartphones, the requirements imposed on the under-tip glass (UTG) are often asymmetrical with respect to its two main surfaces. For example, such devices are generally arranged to be foldable such that the UTG surface facing the user is on the inside of the bend. This UTG surface therefore faces particularly high requirements for impact resistance because it is directly exposed to various types of external impacts. On the other hand, the opposite UTG surface is on the outside of the bend and therefore faces particularly high requirements for bending strength due to the tensile stress induced by the bending.

[0010] Therefore, there is a need for a UTG that combines a first surface with particularly high impact resistance and a second surface with particularly high bending strength.

[0011] A conventionally used approach to further enhance the strength of UTG is the introduction of a chamfered structure at its edges. This is generally done during the stacking process of the glass articles using an etching solution. Since the etching solution accesses the edges of the article symmetrically, this results in a symmetrical chamfered structure that is not optimized with respect to the aforementioned asymmetric strength requirements. [Overview of the project] [Problems that the invention aims to solve]

[0012] Therefore, the object of the present invention is to resolve the problems of the prior art. In particular, the object of the present invention is to provide an asymmetric UTG optimized for the asymmetric requirements of impact resistance and bendability in applications such as smartphones and other electronic devices. It is also the object of the present invention to provide a method for manufacturing such an UTG. [Means for solving the problem]

[0013] The aforementioned problems are resolved by the subject matter of the claims.

[0014] The present invention involves the idea of ​​protecting a second surface of a glass article not only during chamfer etching but also during subsequent etching steps performed to slim the glass article to a desired thickness. This is advantageous in several respects. The surface roughness of the second surface can be kept low. Protecting the second surface of the glass article during slimming (but not the first surface of the glass article) results in an asymmetry of the chamfered structure that reflects the need for asymmetry suggested by the use of UTG in foldable electronic devices, such as smartphones. The high surface quality of the second surface makes it ideal for forming the outer surface of the bend and withstanding the resulting tensile stress. In particular, the second surface can have high ball-on-ring breaking strength and high two-point bending strength.

[0015] On the other hand, the first surface of UTG is very well suited to facing the user of electronic devices because the first surface has high impact resistance, especially when the UTG is chemically strengthened. This is surprising. While we do not wish to be bound by any particular theory, the high impact resistance of the first surface can be explained at least in part by its relatively high density. The first surface corresponds to the area of ​​glass article that was located inside the article before the slimming process. Thus, a slower cooling rate occurs during manufacturing, resulting in a higher density. The higher density is associated with a higher CS value that can be achieved when chemically strengthened.

[0016] The glass article of the present invention is very well suited for use in foldable electronic devices, particularly in cases where the first surface of the glass article faces the outside of the device and therefore requires high impact resistance, and the second surface of the glass article is the outer surface when bent and therefore requires high bending strength due to the generation of tensile stress.

[0017] In the first embodiment, the present invention relates to a glass article having a thickness of 10 μm to 150 μm, • Includes a first surface, a second surface, and at least one end connecting the first surface and the second surface, • Surface roughness R of the second surface a The arithmetic mean roughness is a maximum of 0.30 nm. The above relates to glass articles.

[0018] In a second embodiment, the present invention relates to a glass article having a thickness of 10 μm to 150 μm, • Includes a first surface, a second surface, and at least one end connecting the first surface and the second surface, The first surface and the second surface are essentially parallel to each other. • The aforementioned end has the following three surfaces: - A vertical surface that is essentially perpendicular to the first surface and the second surface, - A first connecting surface that connects the vertical surface and the first surface, and - A second connecting surface that connects the vertical surface and the second surface. It has a chamfered structure including, The aforementioned chamfering structure is - The tangent A to the first connecting surface intersects the tangent B to the first surface at a distance d1 from the tangent C to the vertical surface, and - The tangent D to the second connecting surface intersects the tangent E to the second surface at a distance d2 from the tangent C to the vertical surface. Having a profile, here - Both d1 and d2 are measured perpendicular to the tangent C to the vertical surface, - Tangents A to E are obtained by fitting each tangent to the corresponding surface in the profile of the chamfered structure. The chamfered structure is asymmetrical such that d1 ≠ d2. The above relates to glass articles.

[0019] In a third embodiment, the present invention relates to a glass article having a thickness of 10 μm to 150 μm, • Includes a first surface, a second surface, and at least one end connecting the first surface and the second surface, The first surface has impact resistance corresponding to a pen drop height of at least 5 mm, and The second surface has a ball-on-ring breaking force of at least 5.0 N and / or a two-point bending strength of at least 2,000 MPa. The above relates to glass articles.

[0020] In a fourth aspect, the present invention relates to a method for manufacturing a glass article having a first surface and a second surface, and more particularly to a method for manufacturing a glass article according to the present invention, the following steps: a) The stage of preparing glass articles, b) A step of forming a stack assembly comprising a plurality of glass articles and at least one adhesive layer between two adjacent glass articles, wherein a first surface of a glass article is in contact with a first adhesive layer containing a first adhesive, and a second surface of a glass article is in contact with a second adhesive layer containing a second adhesive, c) The step of bringing the stack assembly into contact with the first etching solution, d) The step of delayering the stack assembly by removing the first adhesive layer, thereby obtaining a sandwich assembly consisting of two glass articles and a second adhesive layer located between the two glass articles. e) The step of bringing the sandwich assembly into contact with the second etching solution, f) The step of delayering the sandwich assembly by removing the second adhesive layer, The method includes the foregoing.

[0021] The present invention relates to a method for manufacturing a plurality of glass articles having a first surface and a second surface, and more particularly to a method for manufacturing glass articles according to the present invention, comprising the following steps: a) The stage of preparing multiple glass articles, b) The step of forming a stack assembly comprising the plurality of glass articles and at least one adhesive layer between two adjacent glass articles, wherein a first surface of a glass article is in contact with a first type of adhesive and a second surface of a glass article is in contact with a second type of adhesive, c) The step of bringing the stack assembly or a smaller stack assembly obtained therefrom into contact with the first etching solution. d) The step of delayering the stack assembly or a smaller stack assembly obtained therefrom by removing the first type of adhesive, thereby obtaining a sandwich assembly consisting of two glass articles and a second type of adhesive located between the two glass articles. e) The step of bringing the sandwich assembly into contact with the second etching solution, f) The step of delayering the sandwich assembly by removing the second type of adhesive, The same also relates to the aforementioned method, including the method described above.

[0022] The present invention also relates to a bendable device, including the glass article of the present invention.

[0023] The present invention relates to a glass article having a thickness of 10 μm to 150 μm, comprising a first surface, a second surface, and at least one end connecting the first surface and the second surface. A) Surface roughness R of the second surface a The (arithmetic mean roughness) is a maximum of 0.30 nm. B) The first surface and the second surface are essentially parallel to each other, • The aforementioned end has the following three surfaces: - Vertical surfaces that are essentially perpendicular to the first surface and the second surface. - A first connecting surface that connects the vertical surface and the first surface, and - A second connecting surface that connects the vertical surface and the second surface. It has a chamfered structure including, The aforementioned chamfering structure is - The tangent A to the first connecting surface intersects the tangent B to the first surface at a distance d1 from the tangent C to the vertical surface, and - The tangent D to the second connecting surface intersects the tangent E to the second surface at a distance d2 from the tangent C to the vertical surface. Having a profile, here - Both d1 and d2 are measured perpendicular to the tangent C to the vertical surface, - Tangents A to E are obtained by fitting each tangent to the corresponding surface in the profile of the chamfered structure. • The chamfered structure is asymmetrical such that d1 ≠ d2, and / or C) The first surface has impact resistance corresponding to a pen drop height of at least 5 mm, and the second surface has a ball-on-ring breaking force of at least 5.0 N and / or a two-point bending strength of at least 2,000 MPa. The present invention relates to the glass article characterized by the above.

[0024] In some embodiments, the present invention relates to a glass article having a thickness of 10 μm to 150 μm, comprising a first surface, a second surface, and at least one end connecting the first surface and the second surface. A) Surface roughness R of the second surface a The (arithmetic mean roughness) is a maximum of 0.30 nm, and B) The first surface and the second surface are essentially parallel to each other, • The aforementioned end has the following three surfaces: - Vertical surfaces that are essentially perpendicular to the first surface and the second surface. - A first connecting surface that connects the vertical surface and the first surface, and - A second connecting surface that connects the vertical surface and the second surface. It has a chamfered structure including, The aforementioned chamfering structure is - The tangent A to the first connecting surface intersects the tangent B to the first surface at a distance d1 from the tangent C to the vertical surface, and - The tangent D to the second connecting surface intersects the tangent E to the second surface at a distance d2 from the tangent C to the vertical surface. Having a profile, here - Both d1 and d2 are measured perpendicular to the tangent C to the vertical surface, - Tangents A to E are obtained by fitting each tangent to the corresponding surface in the profile of the chamfered structure. The chamfered structure is asymmetrical such that d1 ≠ d2. The present invention relates to the glass article characterized by the above.

[0025] In some embodiments, the present invention relates to a glass article having a thickness of 10 μm to 150 μm, comprising a first surface, a second surface, and at least one end connecting the first surface and the second surface. A) Surface roughness R of the second surface a The (arithmetic mean roughness) is a maximum of 0.30 nm, and B) The first surface has impact resistance corresponding to a pen drop height of at least 5 mm, and the second surface has a ball-on-ring breaking force of at least 5.0 N and / or a two-point bending strength of at least 2,000 MPa. The present invention relates to the glass article characterized by the above.

[0026] In some embodiments, the present invention relates to a glass article having a thickness of 10 μm to 150 μm, comprising a first surface, a second surface, and at least one end connecting the first surface and the second surface. A) The first surface and the second surface are essentially parallel to each other, • The aforementioned end has the following three surfaces: - Vertical surfaces that are essentially perpendicular to the first surface and the second surface. - A first connecting surface that connects the vertical surface and the first surface, and - A second connecting surface that connects the vertical surface and the second surface. It has a chamfered structure including, The aforementioned chamfering structure is - The tangent A to the first connecting surface intersects the tangent B to the first surface at a distance d1 from the tangent C to the vertical surface, and - The tangent D to the second connecting surface intersects the tangent E to the second surface at a distance d2 from the tangent C to the vertical surface. Having a profile, here - Both d1 and d2 are measured perpendicular to the tangent C to the vertical surface, - Tangents A to E are obtained by fitting each tangent to the corresponding surface in the profile of the chamfered structure. The chamfered structure is asymmetrical such that d1 ≠ d2, and B) The first surface has impact resistance corresponding to a pen drop height of at least 5 mm, and the second surface has a ball-on-ring breaking force of at least 5.0 N and / or a two-point bending strength of at least 2,000 MPa. The present invention relates to the glass article characterized by the above.

[0027] In some embodiments, the present invention relates to a glass article having a thickness of 10 μm to 150 μm, comprising a first surface, a second surface, and at least one end connecting the first surface and the second surface. A) Surface roughness R of the second surface a The (arithmetic mean roughness) is a maximum of 0.30 nm. B) The first surface and the second surface are essentially parallel to each other, • The aforementioned end has the following three surfaces: - Vertical surfaces that are essentially perpendicular to the first surface and the second surface. - A first connecting surface that connects the vertical surface and the first surface, and - A second connecting surface that connects the vertical surface and the second surface. It has a chamfered structure including, The aforementioned chamfering structure is - The tangent A to the first connecting surface intersects the tangent B to the first surface at a distance d1 from the tangent C to the vertical surface, and - The tangent D to the second connecting surface intersects the tangent E to the second surface at a distance d2 from the tangent C to the vertical surface. Having a profile, here - Both d1 and d2 are measured perpendicular to the tangent C to the vertical surface, - Tangents A to E are obtained by fitting each tangent to the corresponding surface in the profile of the chamfered structure. The chamfered structure is asymmetrical such that d1 ≠ d2, and C) The first surface has impact resistance corresponding to a pen drop height of at least 5 mm, and the second surface has a ball-on-ring breaking force of at least 5.0 N and / or a two-point bending strength of at least 2,000 MPa. The present invention relates to the glass article characterized by the above.

[0028] The glass articles of the present invention can be, for example, sheets or sheet-like articles, particularly round articles, or rectangular or square articles having length and width. The length and width of the glass article are preferably much longer than the thickness of the article. For example, the length and / or 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 width may be up to 500 mm, up to 400 mm, up to 300 mm, up to 200 mm, up to 150 mm, up to 125 mm, up to 100 mm, or up to 70 mm. The ratio of length to width may be 1:1 or greater. In some embodiments, the glass article may have a notch for a front camera, particularly in smartphone applications, and / or holes or recesses for a camera and / or microphone or speaker.

[0029] In one embodiment of the present invention, the glass article 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, 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 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 width may be, for example, up to 500 mm, up to 400 mm, up to 300 mm, up to 200 mm, up to 150 mm, up to 125 mm, up to 100 mm, or up to 70 mm.

[0030] Preferably, the article has exactly one end connecting its first surface and second surface. Depending on the shape of the article, the end may have different sides. For example, in the case of a sheet or sheet-like article having a rectangle or square shape, the end has four sides, where two opposing sides represent the length of the article and the remaining two opposing sides represent the width of the article. The position where two adjacent sides of the end connect is generally referred to as a corner.

[0031] The glass article of the present invention has a thickness of 10 μm to 150 μm, for example, 15 μm to 120 μm, 20 μm to 100 μm, 25 μm to 90 μm, 30 μm to 80 μm, 35 μm to 70 μm, 40 μm to 60 μm, or 45 μm to 50 μm. The thickness of the glass article may be, for example, at least 10 μm, at least 15 μm, at least 20 μm, at least 25 μm, at least 30 μm, at least 35 μm, at least 40 μm, or at least 45 μm. The thickness of the glass article may be, for example, up to 150 μm, up to 120 μm, up to 100 μm, up to 90 μm, up to 80 μm, up to 70 μm, up to 60 μm, or up to 50 μm.

[0032] Average roughness (R a) is a measure of surface texture. It is quantified by the vertical deviation from the ideal form of the actual surface. Conventionally, 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.

[0033] Surface roughness R a is preferably specified 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.

[0034] Preferably, the surface roughness R of the second surface a is, particularly for an area of 2×2 μm 2 or 10×10 μm 2 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 surface roughness R of the second surface a is, particularly for an area of 2×2 μm 2 or 10×10 μm 2 may be, for example, at least 0.05 nm, at least 0.08 nm, at least 0.10 nm, or at least 0.12 nm. The surface roughness R of the second surface a is, particularly for an area of 2×2 μm 2 or 10×10 μm 2 may be in the range of, for example, 0.05 - 0.30 nm, 0.08 - 0.25 nm, 0.10 - 0.20 nm, or 0.12 - 0.15 nm.

[0035] <8000315>The surface roughness R of the first surface a is, particularly for an area of 2×2 μm 2 or 10×10 μm 2The area may be, for example, a maximum of 0.80 nm, a maximum of 0.70 nm, a maximum of 0.60 nm, a maximum of 0.50 nm, a maximum of 0.40 nm, a maximum of 0.30 nm, or a maximum of 0.20 nm. Surface roughness R of the first surface a In particular, 2 × 2 μm 2 or 10 × 10 μm 2 The area may be, for example, at least 0.10 nm, at least 0.11 nm, at least 0.12 nm, at least 0.13 nm, at least 0.14 nm, at least 0.15 nm, or at least 0.16 nm. Surface roughness R of the first surface a In particular, 2 × 2 μm 2 or 10 × 10 μm 2 The area may be in the range of, for example, 0.10-0.80 nm, 0.11-0.70 nm, 0.12-0.60 nm, 0.13-0.50 nm, 0.14-0.40 nm, 0.15-0.30 nm, or 0.16-0.20 nm.

[0036] Surface roughness R of the first surface a The surface roughness R of the second surface is a It can be higher than that. For example, the surface roughness R of the first surface a and the surface roughness R of the second surface a The absolute value of the difference is especially important for 2 × 2 μm 2 or 10 × 10 μm 2 The surface roughness of the first and second surfaces of the area may be at least 0.05 nm, at least 0.10 nm, at least 0.15 nm, or at least 0.20 nm. a and the surface roughness R of the second surface a The absolute value of the difference is especially important for 2 × 2 μm 2 or 10 × 10 μm 2 The surface roughness of the first and second surfaces of the area may be, for example, a maximum of 0.50 nm, a maximum of 0.40 nm, a maximum of 0.30 nm, or a maximum of 0.25 nm. a and the surface roughness R of the second surface a The absolute value of the difference is especially important for 2 × 2 μm 2 or 10 × 10 μm 2The first and second surfaces of the area may be in the range of, for example, 0.05 to 0.50 nm, 0.10 to 0.40 nm, 0.15 to 0.30 nm, or 0.20 to 0.25 nm.

[0037] As described above, the glass articles of the present invention may also be characterized by an asymmetric chamfered structure. A schematic cross-sectional profile of a glass article having an asymmetric chamfered structure is shown in Figure 2. The asymmetry can be best observed and explained based on the cross-sectional image of the chamfered structure profile shown in Figure 3. To obtain such an image, the glass article is observed in transmitted light mode using an optical microscope. A magnification of 200x is used. Since the focal point is on the top surface, the edges appear very sharp. The glass article is positioned so that the top surface is not tilted. Therefore, the top surface is perpendicular to the direction of light. Images of particularly good quality are generally obtained using an automatic white balance, automatic brightness and automatic contrast, especially when using a Nikon Y-TV55 microscope.

[0038] As shown in Figure 3, the asymmetry of the chamfered structure can be easily explained in the microscopic image by fitting the tangents to the corresponding surfaces (tangent A to the first connecting surface, tangent B to the first surface, tangent C to the perpendicular surface, tangent D to the second connecting surface, and tangent E to the second surface).

[0039] Fitting tangents to each surface can be done manually using any suitable image processing software, such as ImageJ, PowerPoint, or Photoshop. Those skilled in the art will understand that they are well aware of even more suitable software programs. Fitting the lines can be easily done manually; a sufficiently accurate fit can be obtained without considerable effort. However, if desired, fitting can be performed using, for example, the least squares method, and especially with the support of additional software, to obtain the best fit.

[0040] In particular, as shown in Figure 3, the transition of one surface to another cannot always be specified at a single specific point. Specifically, the second connecting surface, and even more significantly the first connecting surface, may deviate from a straight line toward the transition to the second or first surface, respectively. However, this deviation only concerns small portions of the first and second connecting surfaces. Therefore, when fitting a tangent to the first connecting surface, the best fit is obtained toward the transition of the first connecting surface to the perpendicular surface in order to minimize the deviation of the tangent from the first connecting surface, while a larger deviation toward the transition of the first connecting surface to the first surface is acceptable. The same applies to fitting a tangent to the second connecting surface.

[0041] As shown in Figure 3, tangent A to the first connecting surface intersects tangent B to the first surface at a distance d1 from tangent C to the vertical surface. Similarly, tangent D to the second connecting surface intersects tangent E to the second surface at a distance d2 from tangent C to the vertical surface. Both d1 and d2 are measured perpendicular to tangent C to the vertical surface. The lengths of distances d1 and d2 can be measured using any suitable image processing software, such as ImageJ, PowerPoint, or Photoshop. The measurement may involve comparing the lengths of distances d1 and d2 to the lengths of scale bars, respectively.

[0042] In an asymmetrical chamfered structure, d1 is not equal to d2. In particular, d1 may be greater than d2.

[0043] The absolute value of the difference between d1 and d2 may be, for example, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, or at least 90% of the thickness of the glass article. The absolute value of the difference between d1 and d2 may be, for example, up to 200%, up to 180%, up to 160%, up to 140%, up to 120%, up to 110%, or up to 100% of the thickness of the glass article. The absolute value of the difference between d1 and d2 may be, for example, in the range of 30% to 200%, 40% to 180%, 50% to 160%, 60% to 140%, 70% to 120%, 80% to 110%, or 90% to 100% of the thickness of the glass article.

[0044] The absolute value of the difference between d1 and d2 may be, for example, at least 15 μm, at least 20 μm, at least 25 μm, at least 30 μm, at least 35 μm, or at least 40 μm. The absolute value of the difference between d1 and d2 may be, for example, up to 100 μm, up to 90 μm, up to 80 μm, up to 70 μm, up to 60 μm, or up to 50 μm. The absolute value of the difference between d1 and d2 may be in the range of, for example, 15 to 100 μm, 20 to 90 μm, 25 to 80 μm, 30 to 70 μm, 35 to 60 μm, or 40 to 50 μm.

[0045] The distance d1 may be, for example, at least 50 μm, at least 60 μm, at least 70 μm, at least 80 μm, or at least 90 μm. The distance d1 may be, for example, up to 200 μm, up to 175 μm, up to 150 μm, up to 125 μm, or up to 100 μm. The distance d1 may be in the range of, for example, 50 to 200 μm, 60 to 175 μm, 70 to 150 μm, 80 to 125 μm, or 90 to 100 μm.

[0046] The distance d2 may be, for example, at least 30 μm, at least 35 μm, at least 40 μm, at least 45 μm, or at least 50 μm. The distance d2 may be, for example, up to 100 μm, up to 90 μm, up to 80 μm, up to 70 μm, or up to 60 μm. The distance d2 may be in the range of, for example, 30 to 100 μm, 35 to 90 μm, 40 to 80 μm, 45 to 70 μm, or 50 to 60 μm.

[0047] The present invention relates to a glass article that is asymmetrical with respect to the surface roughness of the first and second surfaces, with respect to the chamfer structure, and / or with respect to the impact and bending properties of the first and second surfaces. In particular, the glass article of the present invention may have a first surface having very good impact resistance and a second surface having very good bending strength. This is particularly advantageous for using the glass article in bendable devices, such as smartphones, where the first surface faces various external impacts and the second surface is the outer surface of the glass article when bent.

[0048] The measure of impact resistance is the pen drop height. The higher the pen drop height, the higher the impact resistance. The pen drop height is the fracture height specified in the pen drop test, in which the glass article is mounted on one surface of a 150 μm thick substrate, and the substrate consists of a 25 μm thick layer of pressure-sensitive adhesive (PSA) material, a 50 μm thick layer of polyethylene (PE), another 25 μm thick layer of pressure-sensitive adhesive (PSA), and another 50 μm thick layer of polyethylene (PE), from the side in contact with the glass to the side in contact with the marble stage. Beneath the 150 μm thick substrate is a flat 10 cm thick marble stage with a polished smooth surface. Subsequently, the other surface of the glass article facing upwards (i.e., the surface where the pen drop height is actually tested) is struck with a 14 g ballpoint pen (manufactured by Chenguang) with a tungsten carbide ball diameter of 0.5 mm, increasing the height from 5 mm until the glass breaks. Next, the destruction height is recorded as the pen drop height.

[0049] The first surface of the glass article may have impact resistance corresponding to pen drop heights 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 of the glass article may have impact resistance corresponding to pen drop heights 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 of the glass article may have impact resistance corresponding to pen drop heights 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 of the glass article may have impact resistance corresponding to pen drop heights 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 another embodiment, the first surface of the glass article may have impact resistance corresponding to pen drop heights 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.

[0050] It is also possible to normalize the pen drop height with respect to the thickness of the glass object. The normalized pen drop height is given by the pen drop height (μm) and the square of the object's thickness (μm). 2 This can be obtained as a ratio of 10,000 μm to 50 μm. For example, if a particular glass article has a pen drop height of 10 mm (= 10,000 μm) and the article thickness is 50 μm, the normalized pen drop height is 10,000 μm multiplied by 50 μm. 2 μm 2This can be obtained by dividing by , yielding a value of 4.0 per μm for a normalized pen drop height.

[0051] The first surface of the glass article may have impact resistance corresponding to a normalized pen drop height of at least 4.5 per μm, at least 5.0 per μm, at least 5.5 per μm, at least 6.0 per μm, at least 6.5 per μm, at least 7.0 per μm, at least 7.5 per μm, at least 8.0 per μm, at least 8.5 per μm, at least 9.0 per μm, at least 9.5 per μm, at least 10.0 per μm, or at least 10.5 per μm. The first surface of the glass article may have impact resistance corresponding to normalized pen drop heights of up to 60.0 per μm, up to 50.0 per μm, up to 45.0 per μm, up to 40.0 per μm, up to 35.0 per μm, up to 30.0 per μm, up to 25.0 per μm, up to 20.0 per μm, up to 18.0 per μm, up to 16.0 per μm, up to 14.0 per μm, up to 12.0 per μm, or up to 11.0 per μm. The first surface of the glass article may have impact resistance corresponding to normalized pen drop heights in the range of 4.5 to 60.0 per μm, 5.0 to 50.0 per μm, 5.5 to 45.0 per μm, 6.0 to 40.0 per μm, 6.5 to 35.0 per μm, 7.0 to 30.0 per μm, 7.5 to 25.0 per μm, 8.0 to 20.0 per μm, 8.5 to 18.0 per μm, 9.0 to 16.0 per μm, 9.5 to 14.0 per μm, 10.0 to 12.0 per μm, or 10.5 to 11.0 per μm.

[0052] The second surface of the glass article may have impact resistance corresponding to a normalized pen drop height of at least 2.0 per μm, at least 2.5 per μm, at least 3.0 per μm, at least 3.5 per μm, at least 4.0 per μm, at least 4.5 per μm, at least 5.0 per μm, at least 5.5 per μm, at least 6.0 per μm, at least 6.5 per μm, at least 7.0 per μm, at least 7.5 per μm, or at least 8.0 per μm. The second surface of the glass article may have impact resistance corresponding to normalized pen drop heights of up to 50.0 per μm, up to 45.0 per μm, up to 40.0 per μm, up to 35.0 per μm, up to 30.0 per μm, up to 25.0 per μm, up to 20.0 per μm, up to 18.0 per μm, up to 16.0 per μm, up to 14.0 per μm, up to 12.0 per μm, up to 10.0 per μm, or up to 9.0 per μm. The second surface of the glass article may have impact resistance corresponding to normalized pen drop heights in the range of 2.0 to 50.0 per μm, 2.5 to 45.0 per μm, 3.0 to 40.0 per μm, 3.5 to 35.0 per μm, 4.0 to 30.0 per μm, 4.5 to 25.0 per μm, 5.0 to 20.0 per μm, 5.5 to 18.0 per μm, 6.0 to 16.0 per μm, 6.5 to 14.0 per μm, 7.0 to 12.0 per μm, 7.5 to 10.0 per μm, or 8.0 to 9.0 per μm.

[0053] As described above, the pen drop height on the first surface of the glass article is particularly high. In particular, the pen drop height on the first surface of the glass article may be higher than the pen drop height on the second surface of the glass article. The ratio of the pen drop height on the first surface to the pen drop height on the second surface may be, for example, at least 1.05, at least 1.10, at least 1.15, at least 1.20, at least 1.25, at least 1.30, at least 1.35, or at least 1.40. The ratio of the pen drop height on the first surface to the pen drop height on the second surface may be, for example, up to 2.50, up to 2.25, up to 2.00, up to 1.90, up to 1.80, up to 1.70, up to 1.60, or up to 1.50. The ratio of the pen drop height on the first surface to the pen drop height on the second surface may be, for example, in the range of 1.05 to 2.50, 1.10 to 2.25, 1.15 to 2.00, 1.20 to 1.90, 1.25 to 1.80, 1.30 to 1.70, 1.35 to 1.60, or 1.40 to 1.50.

[0054] The second surface of a glass article may be particularly suitable for withstanding the tensile stress generated on the second surface when the glass article is bent such that the second surface is the outer surface of the bend. This is reflected in the second surface having particularly high ball-on-ring breaking strength and / or two-point bending strength. In particular, the ball-on-ring breaking strength and / or two-point bending strength of the second surface of the glass article may be higher than that of the first surface, respectively.

[0055] As schematically shown in Figure 4, the ball-on-ring breaking force can be tested by placing the surface 45 of a glass article 41 on a steel ring 42, the ring 42 having an inner diameter of 4 mm and an outer diameter of 6 mm. The ring 42 is 3 mm deep, and its walls are 1 mm thick, with a wall tip having a semicircle with a cross-section of 1 mm. To test the ball-on-ring breaking force, the end of the glass article 41 is at least 20 mm away from the center of the ring 42. A tungsten carbide ball 43 with a diameter of 1 mm is pressed against the surface 44 of the glass article 41 at a speed of 5 mm / min along the central axis of the ring 42 until the glass closes. The force at the time of fracture is recorded as the ball-on-ring breaking force.

[0056] Depending on which surface of the glass article 41 is in contact with the ring 42 or the ball 43, the ball-on-ring breaking force of the first or second surface of the glass article 41 can be tested. The ball-on-ring test described herein is adapted to determine the ball-on-ring breaking force of a specific surface of the glass article 41 in contact with the steel ring 42. For example, if the second surface of the glass article 41 is the surface 45 in contact with the steel ring 42, while the first surface of the glass article 41 is the surface 44 in contact with the ball 43, the product of the ball-on-ring test is the ball-on-ring breaking force of the second surface. However, if the first surface of the glass article 41 is the surface 45 in contact with the steel ring 42, while the second surface of the glass article 41 is the surface 44 in contact with the ball 43, the product of the ball-on-ring test is the ball-on-ring breaking force of the first surface. Tensile stress occurs on the surface 45 of the glass article 41 during the ball-on-ring test. Therefore, the product of the ball-on-ring test is the ball-on-ring fracture force of surface 45.

[0057] The second surface of the glass article may have a ball-on-ring breaking force of 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 second surface of the glass article may have a ball-on-ring breaking force of up to 50.0 N, up to 40.0 N, up to 30.0 N, up to 25.0 N, up to 22.5 N, or up to 20.0 N. The second surface of the glass article may have a ball-on-ring breaking force in the range of 5.0 to 50.0 N, 7.5 to 40.0 N, 10.0 to 30.0 N, 12.5 to 25.0 N, 15.0 to 22.5 N, or 17.5 to 20.0 N.

[0058] The first surface of the glass article may have 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, or at least 12.5 N. The second surface of the glass article may have a ball-on-ring breaking force of up to 30.0 N, up to 25.0 N, up to 22.5 N, up to 20.0 N, up to 17.5 N, or up to 15.0 N. The second surface of the glass article may have a ball-on-ring breaking force in the range of 1.0 to 30.0 N, 2.0 to 25.0 N, 5.0 to 22.5 N, 7.5 to 20.0 N, 10.0 to 17.5 N, or 12.5 to 15.0 N.

[0059] As described above, the ball-on-ring fracture force of the second surface of the glass article is particularly high. In particular, the ball-on-ring fracture force of the second surface of the glass article may be higher than that of the first surface of the glass article. The ratio of the ball-on-ring fracture force of the second surface to that of the first surface may be, for example, at least 1.05, at least 1.10, at least 1.15, at least 1.20, or at least 1.25. The ratio of the ball-on-ring fracture force of the second surface to that of the first surface may be, for example, up to 2.00, up to 1.75, up to 1.50, up to 1.40, or up to 1.30. The ratio of the ball-on-ring breaking force of the second surface to the ball-on-ring breaking force of the first surface may be in the range of, for example, 1.05 to 2.00, 1.10 to 1.75, 1.15 to 1.50, 1.20 to 1.40, or 1.25 to 1.30.

[0060] The particularly good bendability of the glass article of the present invention is also reflected in the particularly high two-point bending strength (2PB strength) of the second surface. To test the 2PB strength, the glass article is placed in a U-shape between two parallel metal plates. The two plates are large enough to cover the entire glass article. Then, one of the plates is moved toward the other at a speed of 60 mm / min while maintaining parallelism until the glass article breaks. The 2PB strength is σ = 1.198Ed / (Dd) The formula is calculated by the equation, where σ is the calculated 2PB strength, E is the Young's modulus of the glass, d is the thickness of the glass article, and D is the distance between the two plates at the time of fracture.

[0061] The product of the 2PB test is the 2PB strength of the surface of the glass article that is the outer surface of the bend. For example, if a glass article is bent such that the second surface is the outer surface of the bend and the first surface is the inner surface of the bend, the product of the 2PB test is the 2PB strength of the second surface of the glass article.

[0062] The second surface of the glass article may have a 2PB strength of, for example, 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 second surface of the glass article may have a 2PB strength of, for example, up to 10,000 MPa, up to 7500 MPa, up to 6000 MPa, up to 5000 MPa, up to 4500 MPa, up to 4000 MPa, or up to 3500 MPa. The second surface of the glass article may have a 2PB strength in the range of, for example, 1500-10,000 MPa, 1750-7500 MPa, 2000-6000 MPa, 2250-5000 MPa, 2500-4500 MPa, 2750-4000 MPa, or 3000-3500 MPa.

[0063] The first surface of the glass article may have a 2PB strength of, for example, at least 1000 MPa, at least 1250 MPa, at least 1500 MPa, at least 1750 MPa, at least 2000 MPa, at least 2250 MPa, or at least 2500 MPa. The first surface of the glass article may have a 2PB strength of, for example, up to 7500 MPa, up to 5000 MPa, up to 4500 MPa, up to 4000 MPa, up to 3500 MPa, up to 3000 MPa, or up to 2750 MPa. The first surface of the glass article may have a 2PB strength in the range of, for example, 1000-7500 MPa, 1250-5000 MPa, 1500-4500 MPa, 1750-4000 MPa, 2000-3500 MPa, 2250-3000 MPa, or 2500-2750 MPa.

[0064] As described above, the 2PB strength of the second surface of the glass article is particularly high. In particular, the 2PB strength of the second surface of the glass article may be higher than that of the first surface of the glass article. The ratio of the 2PB strength of the second surface to the 2PB strength of the first surface may be, for example, at least 1.05, at least 1.10, at least 1.15, at least 1.20, or at least 1.25. The ratio of the 2PB strength of the second surface to the 2PB strength of the first surface may be, for example, up to 2.00, up to 1.75, up to 1.50, up to 1.40, or up to 1.30. The ratio of the 2PB strength of the second surface to the 2PB strength of the first surface may be, for example, in the range of 1.05 to 2.00, 1.10 to 1.75, 1.15 to 1.50, 1.20 to 1.40, or 1.25 to 1.30.

[0065] The glass articles of the present invention can be chemically strengthened, in particular, by subjecting them to ion exchange treatment.

[0066] Compressive stress (CS), also known as "pressure stress" or "surface stress," is the stress that arises from the displacement action exerted on the glass network through the glass surface after ion exchange, while deformation does not occur in the glass.

[0067] The "penetration depth," or "ion exchange layer depth," or "ion exchange depth" ("layer depth" or "ion exchange layer depth," DoL) is the thickness of the glass surface layer where ion exchange occurs and compressive stress is generated. The compressive stress CS and penetration depth DoL can be measured optically (particularly by the waveguide mechanism) using a commercially available stress meter FSM6000 (e.g., LUKEO Corporation, Tokyo, Japan).

[0068] When CS is induced on one or both sides of a glass sheet, a tensile stress must be induced in the central region of the glass to balance the stress according to the third principle of Newton's laws; this is called the internal tensile stress (CT). CT can be calculated from the measured CS value and DoL value.

[0069] Ion exchange refers to the hardening or chemical strengthening of glass through an ion exchange process (also called chemical strengthening), and the method 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 to exchange them with alkali ions within the glass. Monovalent ions in the salt bath have a larger radius than alkali ions within the glass. Compressive stress in the glass is formed after ion exchange due to the larger ions intervening in the glass network. 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 increases its scratch resistance. Typical salts used for chemical strengthening include, for example, K + It contains molten salt or a salt mixture. Any salt bath for chemical strengthening contains Na + Contains and / or K + The molten salt bath contains or is a mixture thereof. Any salts include NaNO3, KNO3, NaCl, KCl, Na2SO4, K2SO4, Na2CO3, K2CO3, and K2Si2O5. Additives, such as NaOH, KOH, and other sodium or potassium salts, are also used to better control the rate of ion exchange for chemical strengthening. Ion exchange can take place, for example, in KNO3, at temperatures in the range of 300°C to 480°C, particularly 340°C to 450°C, or 390°C to 450°C, for a period of, for example, 30 minutes to 48 hours, particularly about 20 minutes. Chemical strengthening is not limited to a single step. It may involve multiple steps in one or more salt baths with varying concentrations of alkali metal ions to achieve better strengthening performance. Thus, the glass layer to be chemically strengthened can be strengthened in one step or in multiple steps, for example, two steps. Two-step chemical strengthening is particularly applicable to Li2O-containing glass because lithium can be exchanged for both sodium and potassium ions.

[0070] The chemically strengthened glass article of the present invention may have a surface compressive stress CS1 on a first surface and a surface compressive stress CS2 on a second surface.

[0071] CS1 and / or CS2 may 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 may be, for example, up to 1000 MPa, up to 900 MPa, up to 850 MPa, up to 800 MPa, up to 750 MPa, up to 700 MPa, or up to 650 MPa. CS1 and / or CS2 may be in the range of, for example, 300-1000 MPa, 350-900 MPa, 400-850 MPa, 450-800 MPa, 500-750 MPa, 550-700 MPa, or 600-650 MPa.

[0072] In some embodiments, CS1 and / or CS2 may be less than 600 MPa, for example, a maximum of 550 MPa, a maximum of 500 MPa, or a maximum of 475 MPa. CS1 and / or CS2 may be in the range of, for example, 300-600 MPa, 350-550 MPa, 400-500 MPa, or 450-475 MPa.

[0073] The surface compressive stress CS1 at the first surface may be higher than the surface compressive stress CS2 at the second surface. The first surface corresponds to the area of ​​the glass article that was located inside the article before the slimming process. Thus, a slower cooling rate occurs during manufacturing, resulting in a higher density. The higher density is associated with a higher CS value that can be achieved at the first surface of the glass article when chemically strengthened.

[0074] The absolute value of the difference between CS1 and 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 between CS1 and CS2 may be, for example, a maximum of 100 MPa, a maximum of 90 MPa, a maximum of 80 MPa, a maximum of 70 MPa, or a maximum of 60 MPa. The absolute value of the difference between CS1 and CS2 may be in the range of, for example, 10 to 100 MPa, 15 to 90 MPa, 20 to 80 MPa, 30 to 70 MPa, or 50 to 60 MPa.

[0075] The chemically strengthened glass article of the present invention may have a first compressive stress layer extending from a first surface to a first layer depth DoL1 and a second compressive stress layer extending from a second surface to a second layer depth DoL2.

[0076] 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, up to 20.0 μm, up to 17.5 μm, up to 15.0 μm, or up to 12.5 μm. DoL1 and / or DoL2 may be in the range of, for example, 2.5 to 20.0 μm, 5.0 to 17.5 μm, 7.5 to 15.0 μm, or 10.0 to 12.5 μm.

[0077] DoL1 and / or DoL2 may be adapted to the thickness of the glass article. 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 article. DoL1 and / or DoL2 may be, for example, up to 40.0%, up to 35.0%, up to 30.0%, up to 27.5%, up to 25.0%, or up to 22.5% of the thickness of the glass article. DoL1 and / or DoL2 may be, for example, in the range of 5.0% to 40.0%, 7.5% to 35.0%, 10.0% to 30.0%, 12.5% ​​to 27.5%, 15.0% to 25.0%, or 17.5% to 22.5% of the thickness of the glass article.

[0078] DoL2 may be higher than DoL1. As mentioned above, a slower cooling rate occurs at the first surface of the glass article during manufacturing, resulting in a higher density. The higher density at the first surface may be associated with a lower layer depth DoL1 of the compressive stress layer extending from the first surface toward the center of the glass article, compared to a layer depth DoL2 of the compressive stress layer extending from the second surface toward the center of the glass article. The DoL2 / DoL1 ratio is greater than 1.00 and may be, for example, at least 1.01, at least 1.02, at least 1.03, or at least 1.04. The DoL2 / DoL1 ratio may be, for example, up to 1.20, up to 1.15, up to 1.10, up to 1.07, or up to 1.05. The ratio of DoL2 / DoL1 may be in the range of, for example, >1.00~1.20, 1.01~1.15, 1.02~1.10, 1.03~1.07, or 1.04~1.05.

[0079] The difference between DoL1 and DoL2 can be associated with glass articles having a specific curvature. In particular, a glass article may have a curvature such that the first surface of the glass article is convex and the second surface of the glass article is concave. While we do not wish to be bound by any particular theory, this can be explained at least in part by the fact that the greater layer depth DoL2 of the compressive stress layer extending from the second surface toward the center of the glass article is not fully balanced by the smaller layer depth DoL1 of the compressive stress layer extending from the first surface toward the center of the glass article. As a result, the second surface may be "pushed" toward the center of the glass article (resulting in a concave second surface), while the first surface may be "pushed" outward (resulting in a convex first surface). Generally, in this field, it is an established idea that curvature should be avoided. However, in this case, a specific curvature has been found to be even advantageous for the bendability of the article. In particular, as mentioned above, the first surface of the glass article of the present invention is particularly suitable for facing the user of a bendable electronic device, such as a smartphone, by making it the inner surface of the bend. Furthermore, as mentioned above, it is generally the outer surface of a bend that faces specific problems caused by tensile force. However, the problem that arises toward the inner surface of a bend is so-called crease. Interestingly, the convex first surface of the glass article of the present invention cancels out the problem of creases. Therefore, this makes the first surface even more suitable for being the inner surface of a bend.

[0080] Warpage can be measured, for example, by placing the glass article on a flat surface and then recording the longest distance between the lower surface of the glass article and the flat surface as the warpage. Warpage can also be measured, for example, by a set of feeler gauges, particularly having a resolution of 0.02 mm.

[0081] The glass articles of the present invention may have a curvature of at least 0.5 mm, at least 1.0 mm, at least 1.5 mm, or at least 2.0 mm, particularly when the first surface of the glass article is a convex surface and the second surface of the glass article is a concave surface. The glass articles of the present invention may have a maximum curvature of 5.0 mm, at least 4.0 mm, at least 3.0 mm, or at least 2.5 mm, particularly when the first surface of the glass article is a convex surface and the second surface of the glass article is a concave surface. The glass articles of the present invention may have a curvature in the range of 0.5 to 5.0 mm, 1.0 to 4.0 mm, 1.5 to 3.0 mm, or 2.0 to 2.5 mm, particularly when the first surface of the glass article is a convex surface and the second surface of the glass article is a concave surface. This curvature is also called absolute curvature and indicates the curvature of the glass article.

[0082] However, it is also possible to identify the relative curvature of glass articles, particularly the area-relative curvature and / or length-relative curvature.

[0083] The warp of a glass article can be expressed, for example, by normalizing it with respect to the surface area of ​​one of the two main surfaces of the glass article (area-relative warp). Since both main surfaces of a glass article generally have the same or approximately the same surface area, the same result can be obtained by normalizing the warp with respect to either of the two main surfaces. For example, each of the two main surfaces of a glass article having a length of 50 mm and a width of 30 mm has a surface area of ​​30 × 50 mm. 2 = 1500mm 2 It has the following characteristics. Similarly, each of the two main surfaces of a glass article having a length of 125 mm and a width of 40 mm has a surface area of ​​125 × 40 mm². 2 = 5000mm 2 It has a surface area of ​​5000 mm² for each of the two main surfaces. 2 If such a glass article has a curvature of 2.0 mm (= 2000 μm), then the area relative curvature is 2000 μm = 5000 mm 2 Divide by, that is, 1 mm 2 It becomes approximately 0.4 μm.

[0084] The glass article of the present invention, in particular when the first surface of the glass article is a convex surface and the second surface of the glass article is a concave surface, is 1 mm 2 At least 0.02 μm per 1 mm 2 At least 0.05 μm per 1 mm 2 At least 0.10 μm or 1 mm per unit 2 The glass article of the present invention may have an area relative curvature of at least 0.25 μm per unit area. In particular, when the first surface of the glass article is a convex surface and the second surface of the glass article is a concave surface, 1 mm 2 Maximum thickness per 1 mm 2 Maximum thickness of 2.5 μm per 1 mm 2 Maximum thickness of 1.5 μm or 1 mm per unit area. 2 The glass article of the present invention may have an area relative curvature of up to 1.0 μm per unit area. In particular, when the first surface of the glass article is a convex surface and the second surface of the glass article is a concave surface, 1 mm 2 0.02-5.0 μm per 1 mm 2 Approximately 0.05-2.5 μm per 1 mm 2 0.10-1.5 μm or 1 mm per unit area 2 It may have an area-relative warpage in the range of 0.25 to 1.0 μm per unit area.

[0085] The curvature of a glass article can also be expressed normalized to the longest length of one of the two main surfaces of the glass article (length-relative curvature). Since both main surfaces of a glass article generally have the same or approximately the same longest length, the same result can be obtained by normalizing the curvature to either of the two main surfaces. For a glass article with a round main surface, the longest length is its diameter. For a glass article with a rectangular main surface, the longest length is its diagonal. For example, each of the two main surfaces of a glass article having a length of 50 mm and a width of 30 mm is (30 2 mm 2 +50 2 mm 2The square root of ) has a maximum length of approximately 58.3 mm. Similarly, each of the two main surfaces of a glass article having a length of 125 mm and a width of 40 mm is (125 2 mm 2 +40 2 mm 2 The square root of the longest length is approximately 131.25 mm. If such a glass article has a longest length of 131.25 mm for each of its two main surfaces and has a curvature of 2.0 mm (= 2000 μm), then the length relative curvature is obtained by dividing 2000 μm by 131.25 mm, which is approximately 15.2 μm per mm.

[0086] The glass articles of the present invention may have a relative length curvature of at least 5.0 μm per mm, at least 10.0 μm per mm, at least 12.5 μm per mm, or at least 15.0 μm per mm, particularly when the first surface of the glass article is a convex surface and the second surface of the glass article is a concave surface. The glass articles of the present invention may have a relative length curvature of up to 50.0 μm per mm, up to 40.0 μm per mm, up to 30.0 μm per mm, or up to 20.0 μm per mm, particularly when the first surface of the glass article is a convex surface and the second surface of the glass article is a concave surface. The glass article of the present invention may have a relative curvature in the range of 5.0 to 50.0 μm per mm, 10.0 to 40.0 μm per mm, 12.5 to 30.0 μm per mm, or 15.0 to 20.0 μm per mm, particularly when the first surface of the glass article is a convex surface and the second surface of the glass article is a concave surface.

[0087] The present invention relates to a method for manufacturing a glass article having a first surface and a second surface, and more particularly to a method for manufacturing a glass article according to the present invention, comprising the following steps: a) The stage of preparing glass articles, b) A step of forming a stack assembly comprising a plurality of glass articles (e.g., 3 to 100, or 4 to 20 glass articles) and at least one (preferably exactly one) adhesive layer between two adjacent glass articles, wherein a first surface of a glass article is in contact with a first adhesive layer containing (or consisting of) a first adhesive, and a second surface of a glass article is in contact with a second adhesive layer containing (or consisting of) a second adhesive. c) The step of bringing the stack assembly (or a smaller stack assembly obtained therefrom) into contact with the first etching solution, d) The step of delayering the stack assembly (or a smaller stack assembly obtained therefrom) by removing the first adhesive layer, thereby obtaining a sandwich assembly consisting of two glass articles and a second adhesive layer located between the two glass articles. e) The step of bringing the sandwich assembly into contact with the second etching solution, f) The step of delayering the sandwich assembly by removing the second adhesive layer, The same also relates to the aforementioned method, including the method described above.

[0088] The present invention relates to a method for manufacturing a plurality of glass articles having a first surface and a second surface, and more particularly to a method for manufacturing glass articles according to the present invention, comprising the following steps: a) The stage of preparing multiple glass articles, b) The step of forming a stack assembly comprising the plurality of glass articles and at least one adhesive layer between two adjacent glass articles, wherein a first surface of a glass article is in contact with a first type of adhesive and a second surface of a glass article is in contact with a second type of adhesive, c) The step of bringing the stack assembly or a smaller stack assembly obtained therefrom into contact with the first etching solution. d) The step of delayering the stack assembly or a smaller stack assembly obtained therefrom by removing the first type of adhesive, thereby obtaining a sandwich assembly consisting of two glass articles and a second type of adhesive located between the two glass articles. e) The step of bringing the sandwich assembly into contact with the second etching solution, f) The step of delayering the sandwich assembly by removing the second type of adhesive, The same also relates to the aforementioned method, including the method described above.

[0089] Steps a) to f) are carried out in a specific order. Specifically, step a) is carried out before step b), step b) is carried out before step c), step c) is carried out before step d), step d) is carried out before step e), and / or step e) is carried out before step f). This does not exclude the fact that the method of the present invention may include one or more further steps following any of the above steps a) to f).

[0090] Step a) of preparing a glass article or a group of glass articles may include, for example, a downdraw or overflow fusion method. However, glass articles not obtained by a downdraw or overflow fusion method may also be subjected to the method according to the present invention.

[0091] Step b) forming the stack assembly utilizes two different types of adhesives, a first adhesive and a second adhesive. The present invention includes the idea of ​​protecting the second surface of the (one or more) glass articles from contact with the second etching solution during the second etching step e). In contrast, in order to achieve slimming of the (one or more) glass articles to a desired thickness, the first surface of the (one or more) glass articles must come into contact with the second etching solution. Therefore, the first (type) adhesive is preferably selected so that it can be removed during the abscission step d). This allows the first surface of the (one or more) glass articles to come into contact with the second etching solution during step e). In contrast, the second (type) adhesive is preferably selected so that it cannot be removed during the abscission step d). This allows the second surface of the (one or more) glass articles to be protected from contact with the second etching solution during step e).

[0092] It will be understood that the selection of the first (type) adhesive and the second (type) adhesive is primarily determined by the abscission process to be applied, in particular in step d). For example, if step d) is chosen to include boiling the stack assembly in hot water to remove the first adhesive, then the first (type) adhesive should be chosen such that it is removable by boiling in hot water, while the second (type) adhesive should be chosen such that it is not removable by boiling in hot water. If other abscission methods are applied in step d), the selection of the first (type) adhesive and the second (type) adhesive can be easily adapted accordingly. The difference between the first (type) adhesive and the second (type) adhesive may not be merely a qualitative difference in their removeability (e.g., the first (type) adhesive is removable by hot water and the second (type) adhesive is not). Alternatively or additionally, the first (type) adhesive and the second (type) adhesive can be distinguished by quantitative differences. For example, both the first (type) adhesive and the second (type) adhesive may be removable by the same abscission principle, but the second (type) adhesive may require a quantitatively larger amount of this abscission principle, such as a higher concentration of the removal substance or a higher temperature.

[0093] Adhesives are often distinguished by their curing mechanism. For example, adhesives can be cured by applying energy in the form of pressure, radiation, etc. The first and / or second (type) adhesives of the present invention may be, for example, pressure-sensitive adhesives (PSAs) or UV-curing adhesives. For example, the first (type) adhesive may be a PSA and the second (type) adhesive may be a UV-curing adhesive. Alternatively, the first (type) adhesive may be a UV-curing adhesive and the second (type) adhesive may be a PSA. In some embodiments, both the first (type) adhesive and the second (type) adhesive may be PSAs, or both the first (type) adhesive and the second (type) adhesive may be UV-curing adhesives. It is particularly preferable that both the first (type) adhesive and the second (type) adhesive are UV-curing adhesives.

[0094] According to step c) of the method of the present invention, the stack assembly is brought into contact with the first etching solution. The etching time may be, for example, 1 to 120 minutes, 1 to 60 minutes, 1 to 30 minutes, or 1 to 20 minutes, for example, 2 to 15 minutes, or 5 to 12 minutes. The etching time may be, for example, at least 1 minute, at least 2 minutes, at least 5 minutes, or at least 10 minutes. The etching time may be, for example, up to 120 minutes, up to 60 minutes, up to 30 minutes, up to 20 minutes, up to 15 minutes, or up to 12 minutes. Generally, the thinner the glass articles (one or more), the shorter the etching time that can be selected.

[0095] The etching temperature may be, for example, 1°C to 80°C, or 20°C to 50°C, or for example, 30°C to 45°C.

[0096] The etching solution preferably contains or consists of a mixture of HF and / or NH4HF2 with an inorganic acid (e.g., HCl, HNO3, H2SO4, or a mixture of two or more thereof) and / or an organic acid (e.g., acetic acid, citric acid, oxalic acid, or a mixture of two or more thereof). The total amount of HF and NH4HF2 may be in the range of, for example, 0.1% to 10% by mass, for example, 0.5 to 5% by mass, or 1 to 2% by mass. The total amount of HF and NH4HF2 may be, for example, at least 0.1% by mass, at least 0.5% by mass, or at least 1% by mass. The total amount of HF and NH4HF2 may be, for example, up to 10% by mass, up to 5% by mass, or up to 2% by mass. The mass ratio of the total amount of inorganic acid to the total amount of HF and NH4HF2 may be in the range of, for example, 0.1:1 to 10:1. The mass ratio of the total amount of organic acid to the total amount of HF and NH4HF2 may be in the range of, for example, 0.1:1 to 10:1. The etching solution may contain, for example, 3% by mass of NH4HF2 and 3% by mass of HNO3, or it may contain, or it may consist of 2% by mass of NH4HF2, 2% by mass of HNO3 and 5% by mass of acetic acid, or it may contain, or it may consist of 1% by mass of HF and 1% by mass of HNO3. The etching solution may contain one or more surfactants, for example, alkylphenol ethoxylate, or ammonium lauryl sulfate, or a mixture of alkylphenol ethoxylate and ammonium lauryl sulfate.

[0097] In particular, etching step c) is performed before the first abscission step d). Thus, both the first and second surfaces of the (one or more) glass articles are protected from contact with the first etching solution. Rather, the first etching solution comes into contact with the edges of the glass articles. In particular, etching step c) may be a step in which a chamfered structure is provided on at least one edge of the (one or more) glass articles.

[0098] The method of the present invention may optionally include one or more further steps following the formation of the stack assembly by step b) and before the etching step e). For example, the stack assembly may be cut into smaller stack assemblies. The method of the present invention may also include a step of grinding the edges of the stack assembly or the smaller stack assemblies obtained therefrom before contacting the stack assembly with the first etching solution of step c).

[0099] The glass articles or multiple glass articles prepared in step a) may have relatively large lengths and / or widths. For example, the (single or multiple) glass articles prepared in step a) may have a length of approximately 500 mm and / or a width of approximately 400 mm. Such dimensions may be too large for the various intended applications, for example, for use in foldable electronic devices, such as smartphones. Therefore, it may be desirable to reduce the length and / or width by cutting the (single or multiple) glass articles into smaller glass articles. Such a cutting step is preferably performed following step b) which forms the stack assembly and before the etching step c). Any cutting step results in a smaller stack assembly compared to the stack assembly formed in step b). The term "smaller" refers to a reduction in the length and / or width of the stack assembly obtained in the cutting step compared to the length and / or width of the stack assembly formed in step b). For example, any cutting step may result in a stack assembly having a length of approximately 125 mm and a width of approximately 40 mm, or a stack assembly having a length of approximately 50 mm and a width of approximately 30 mm.

[0100] According to step d) of the method of the present invention, each stack assembly (or a smaller stack assembly obtained therefrom) is abscissed by removing a first adhesive layer or a first type of adhesive. This results in a sandwich assembly consisting of two glass articles and a second adhesive layer or a second type of adhesive located between the two glass articles. The abscission step d) may be adapted depending on the first and second (types) adhesives applied in step b) forming the stack assembly. The abscission step d) is selected such that the first adhesive layer or the first type of adhesive is removed, while the second adhesive layer or the second type of adhesive is not removed. For example, the abscission step d) may include holding the stack assembly (or a smaller stack assembly obtained therefrom) in an abscission liquid at an elevated temperature. The temperature of the abscission liquid may be, for example, above 40°C. The holding time in the abscission liquid may be, for example, 1 to 30 minutes. The abscission liquid may be, for example, an aqueous solution, particularly water.

[0101] Additionally or alternatively, a stack assembly (or a smaller stack assembly obtained therefrom) can be separated by physical force through a valley created by two adjacent chamfers, particularly due to the low adhesive strength between the first adhesive layer and (one or more) glass articles.

[0102] According to step e) of the method of the present invention, the sandwich assembly is brought into contact with a second etching solution. The second etching solution may include, for example, HF. The second etching solution may also contain an inorganic acid and / or an organic acid, in particular in addition to HF. The etching time, etching temperature and / or etching solution may be the same as those described above for the first etching step.

[0103] The etching time may be, for example, 1 to 120 minutes, 1 to 60 minutes, 1 to 30 minutes, or 1 to 20 minutes, for example, 2 to 15 minutes, or 5 to 12 minutes. The etching time may be, for example, at least 1 minute, at least 2 minutes, at least 5 minutes, or at least 10 minutes. The etching time may be, for example, up to 120 minutes, up to 60 minutes, up to 30 minutes, up to 20 minutes, up to 15 minutes, or up to 12 minutes. Generally, the thinner the glass article (one or more), the shorter the etching time that can be selected.

[0104] The etching temperature may be, for example, 1°C to 80°C, or 20°C to 50°C, or for example, 30°C to 45°C.

[0105] The etching solution preferably contains or consists of a mixture of HF and / or NH4HF2 with an inorganic acid (e.g., HCl, HNO3, H2SO4, or a mixture of two or more thereof) and / or an organic acid (e.g., acetic acid, citric acid, oxalic acid, or a mixture of two or more thereof). The total amount of HF and NH4HF2 may be in the range of, for example, 0.1% to 10% by mass, for example, 0.5 to 5% by mass, or 1 to 2% by mass. The total amount of HF and NH4HF2 may be, for example, at least 0.1% by mass, at least 0.5% by mass, or at least 1% by mass. The total amount of HF and NH4HF2 may be, for example, up to 10% by mass, up to 5% by mass, or up to 2% by mass. The mass ratio of the total amount of inorganic acid to the total amount of HF and NH4HF2 may be in the range of, for example, 0.1:1 to 10:1. The mass ratio of the total amount of organic acid to the total amount of HF and NH4HF2 may be in the range of, for example, 0.1:1 to 10:1. The etching solution may contain, for example, 3% by mass of NH4HF2 and 3% by mass of HNO3, or it may contain, or it may consist of 2% by mass of NH4HF2, 2% by mass of HNO3 and 5% by mass of acetic acid, or it may contain, or it may consist of 1% by mass of HF and 1% by mass of HNO3. The etching solution may contain one or more surfactants, for example, alkylphenol ethoxylate, or ammonium lauryl sulfate, or a mixture of alkylphenol ethoxylate and ammonium lauryl sulfate.

[0106] According to step f) of the method of the present invention, the sandwich assembly is delaminated by removing a second adhesive layer or a second type of adhesive, respectively. The glass article of the present invention can be obtained in delamination step f). Step f) can be adapted depending on the second (type of) adhesive applied in step b) forming the stack assembly. For example, delamination step f) may include applying irradiation, particularly UV irradiation, to the sandwich assembly. The radiation may have a peak wavelength in the range of, for example, 250 nm to 450 nm, particularly 300 nm to 400 nm, or 350 nm to 395 nm, for example, about 365 nm or 390 nm. The irradiation intensity is, for example, 200 to 1000 mJ / cm². 2 It may be as follows. The irradiation time may be, for example, 30 seconds to 30 minutes.

[0107] The method of the present invention may further include a step of chemically strengthening the (one or more) glass articles obtained by step f).

[0108] The present invention also relates to a bendable device, including the glass article of the present invention. In particular, the device can be bent such that the first surface is located on the inner surface of the bend and the second surface is located on the outer surface of the bend.

[0109] The bending equipment can be bent to a bending radius of, for example, 1 to 5 mm, such as 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm.

[0110] The devices that can be bent may be, for example, electronic devices, especially smartphones.

[0111] The present invention also relates to the use of glass articles of the present invention in bendable devices, particularly in bendable electronic devices such as smartphones. [Brief explanation of the drawing]

[0112] [Figure 1] This diagram schematically shows the profile of the glass article 10. [Figure 2]This diagram schematically shows the profile of the glass article 20. [Figure 3] This figure shows a microscopic image of a cross-section of a glass article with an asymmetrical chamfered structure. [Figure 4] This is a schematic diagram of the setup for a ball-on-ring test.

[0113] Description of the drawing Figure 1 schematically shows the profile of a glass article 10 including a first surface 11, a second surface 12, and at least one end connecting the first surface 11 and the second surface 12. The first surface 11 and the second surface 12 are essentially parallel to each other. The end has a chamfered structure 16 including three surfaces, namely (i) a vertical surface 13 that is essentially perpendicular to the first surface 11 and the second surface 12, (ii) a first connecting surface 14 that connects the vertical surface 13 and the first surface 11, and (iii) a second connecting surface 15 that connects the vertical surface 13 and the second surface 12. The chamfered structure 16 of the glass article 10 shown in Figure 1 is symmetrical.

[0114] Figure 2 schematically shows the profile of a glass article 20 including a first surface 21, a second surface 22, and at least one end connecting the first surface 21 and the second surface 22. The first surface 21 and the second surface 22 are essentially parallel to each other. The end has a chamfered structure 26 including three surfaces, namely (i) a vertical surface 23 that is essentially perpendicular to the first surface 21 and the second surface 22, (ii) a first connecting surface 24 that connects the vertical surface 23 and the first surface 21, and (iii) a second connecting surface 25 that connects the vertical surface 23 and the second surface 22. The chamfered structure 26 of the glass article 20 shown in Figure 2 is asymmetrical.

[0115] Figure 3 shows a microscopic image of a cross-section of a glass article having an asymmetrical chamfered structure. The image was obtained at a magnification of 200x. The focal point was on the top surface, so the edges appear very sharp. The glass article was positioned so that the top surface was not tilted. Therefore, the top surface was perpendicular to the direction of light. The above image was obtained using a Nikon Y-TV55 microscope with automatic white balance, automatic brightness, and automatic contrast. In the microscopic image, tangents were fitted to the corresponding surfaces (tangent A to the first connecting surface, tangent B to the first surface, tangent C to the perpendicular surface, tangent D to the second connecting surface, and tangent E to the second surface). The fitting of tangents to each surface was performed manually using ImageJ software (version 1.53i, March 24, 2021). As also shown in Figure 3, the second connecting surface, and even more noticeably the first connecting surface, were deviated from a straight line toward the transition to the second or first surface, respectively. Therefore, the tangents were fitted to obtain the best fit toward the transition of the first connecting surface to the vertical surface, while a larger deviation was acceptable toward the transition of the first connecting surface to the first surface. The same procedure was followed for fitting the tangents to the second connecting surface. As shown in Figure 3, tangent A to the first connecting surface intersects tangent B to the first surface at a distance d1 from tangent C to the vertical surface. Similarly, tangent D to the second connecting surface intersects tangent E to the second surface at a distance d2 from tangent C to the vertical surface. Both d1 and d2 were measured perpendicular to tangent C to the vertical surface using ImageJ software. The measurements were performed by comparing the lengths of distances d1 and d2 to the lengths of a 100 μm scale bar. Distance d1 was measured to be 99 μm, and distance d2 was measured to be 56 μm. The thickness of the glass article was 50 μm.

[0116] Figure 4 is a non-scale schematic diagram of the ball-on-ring test setup. Figure 4A shows a top / bottom view of the setup. Figure 4B shows a cross-sectional view of the setup. In the ball-on-ring test, the surface 45 of a glass article 41 is placed on a steel ring 42 having an inner diameter of 4 mm and an outer diameter of 6 mm. The ring is 3 mm deep, and the ring walls are 1 mm thick, with the ends of the walls having semicircles with a cross-section of 1 mm. A tungsten carbide ball 43 with a diameter of 1 mm is pressed against the surface 44 of the glass article 41 at a speed of 5 mm / min along the central axis of the ring until the glass closes. The force at fracture is recorded as the ball-on-ring fracture force. [Examples]

[0117] Example 1 Example 1: 400 x 500 x 0.07 mm manufactured directly by downdraw 3 40 x 125 x 0.05 mm processed from a glass mother sheet. 3 Aluminosilicate glass pieces of the following size. A stack of mother sheets was formed using alternating layers of two types of acrylate-based UV-curing adhesives. The stack was then cut to 40 × 125 mm. 2 The glass was cut into smaller stacks having the specified size. After edge grinding, polishing, and chamfering, the smaller stacks were delaminated between Type #1 adhesive layers by boiling in hot water, thereby obtaining a sandwich assembly consisting of two glass articles and a second adhesive layer located between the two glass articles. The sandwich assembly was then immersed in a mixture of HF and an inorganic / organic acid, where the glass articles were slimmed from 0.07 mm to 0.05 mm. The assembly was then delaminated between Type #2 adhesive layers by UV irradiation. The individual glass pieces were then chemically strengthened in pure KNO3 and subsequently photoetched in a mixture of HF and an inorganic / organic acid to remove a thickness of less than 2 μm from each surface of the glass sample.

[0118] Example 2 Example 2: 400 x 500 x 0.07 mm manufactured directly by downdraw3 30 x 50 x 0.03 mm processed from a glass mother sheet. 3 Aluminosilicate glass pieces of the following size. A stack of mother sheets was formed using alternating layers of two types of acrylate-based UV-curing adhesives. The stack was then cut into 30 x 50 mm 2 The glass was cut into smaller stacks having the following dimensions. After edge grinding, polishing, and chamfering, the smaller stacks were delaminated between Type #1 adhesive layers by boiling in hot water, thereby obtaining a sandwich assembly consisting of two glass articles and a second adhesive layer located between the two glass articles. The sandwich assembly was then immersed in a mixture of HF and an inorganic / organic acid, where the glass articles were slimmed from 0.07 mm to 0.03 mm. The assembly was then delaminated between Type #2 adhesive layers by UV irradiation. The individual glass pieces were then chemically strengthened in pure KNO3 and subsequently photoetched in a mixture of HF and an inorganic / organic acid to remove a thickness of less than 2 μm from each surface of the glass sample.

[0119] Example 3 Example 3: 400 x 500 x 0.1 mm manufactured directly by downdraw 3 30 x 50 x 0.07 mm processed from a glass mother sheet. 3 Aluminosilicate glass pieces of the following size. A stack of mother sheets was formed using alternating layers of two types of acrylate-based UV-curing adhesives. The stack was then cut into 30 x 50 mm 2It was cut into a smaller stack having a size of . Then, after end grinding, polishing and chamfering, the smaller stack was delaminated between the adhesive layers of type #1 by boiling in hot water, where a sandwich assembly consisting of two glass articles and a second adhesive layer located between the two glass articles was obtained. Then, the sandwich assembly was immersed in a mixture of HF and an inorganic / organic acid, where the glass articles were slimmed down from 0.1 mm to 0.07 mm. Then, the assembly was delaminated between the adhesive layers of type #2 by UV irradiation. Then, after chemically strengthening the individual glass pieces in pure KNO3, they were subsequently photoetched in a mixture of HF and an inorganic / organic acid to remove a thickness of less than 2 μm from each surface of the glass samples.

[0120] Comparative Example 1 Comparative Example 1: Aluminosilicate glass pieces having a size of 40×125×0.05 mm processed from a 400×500×0.07 mm glass mother sheet directly produced by down-drawing. One type of acrylate-based UV curable adhesive was used to form a stack of the mother sheets. Then, the stack was cut into a smaller stack having a size of 40×125 mm 3 3 One type of acrylate-based UV curable adhesive was used to form a stack of the mother sheets. Then, the stack was cut into a smaller stack having a size of 40×125 mm 2 It was cut into a smaller stack having a size of . Then, after end grinding, polishing and chamfering, the smaller stack was delaminated between the adhesive layers by boiling in hot water. Then, the individual glass pieces were slimmed down from 0.07 mm to 0.05 mm by immersing them in a mixture of HF and an inorganic / organic acid. Then, after chemically strengthening the slimmed individual glass pieces in pure KNO3, they were subsequently photoetched in a mixture of HF and an inorganic / organic acid to remove a thickness of less than 2 μm from each surface of the glass samples.

[0121] Comparative Example 2 Comparative Example 2: Aluminosilicate glass pieces having a size of 30×50×0.03 mm processed from a 400×500×0.07 mm glass mother sheet directly produced by down-drawing. 3 3Aluminosilicate glass pieces having the following dimensions. A stack of mother sheets was formed using one type of acrylate-based UV-curing adhesive. The stack was then made into a 30 x 50 mm 2 The glass was cut into smaller stacks of the specified size. The smaller stacks were then separated from the adhesive layer by boiling in hot water after edge grinding, polishing, and chamfering. The individual glass pieces were then slimmed from 0.07 mm to 0.03 mm by immersion in a mixture of HF and an inorganic / organic acid. The slimmed individual glass pieces were then chemically strengthened in pure KNO3, followed by photoetching in a mixture of HF and an inorganic / organic acid to remove a thickness of less than 2 μm from each surface of the glass sample.

[0122] Comparative Example 3 Comparative Example 3: 400 x 500 x 0.1 mm manufactured directly by downdraw 3 30 x 50 x 0.07 mm processed from a glass mother sheet. 3 Aluminosilicate glass pieces having the following dimensions. A stack of mother sheets was formed using one type of acrylate-based UV-curing adhesive. The stack was then made into a 30 x 50 mm 2 The glass was cut into smaller stacks of the specified size. The smaller stacks were then separated from the adhesive layer by boiling in hot water after edge grinding, polishing, and chamfering. The individual glass pieces were then slimmed from 0.1 mm to 0.07 mm by immersion in a mixture of HF and an inorganic / organic acid. The slimmed individual glass pieces were then chemically strengthened in pure KNO3, followed by photoetching in a mixture of HF and an inorganic / organic acid to remove a thickness of less than 2 μm from each surface of the glass sample.

[0123] Experimental results The following table provides an overview of the above-described examples and their various characteristics.

[0124] [Table 1]

[0125] Examples of the present invention (Examples 1 to 3) have significant asymmetry in some aspects compared to Comparative Examples (Comparative Examples 1 to 3). The comparative examples were designed to match the corresponding examples (Comparative Example 1 matches Example 1, Comparative Example 2 matches Example 2, and Comparative Example 3 matches Example 3), except that the comparative examples were not manufactured from a stack assembly using two different adhesives. Thus, the second surfaces of Examples 1 to 3 were protected from contact with the etching solution during the slimming stage, while the second surfaces of Comparative Examples 1 to 3 were not protected during slimming. It was observed in Examples 1 to 3 that the protection of the second surface during slimming resulted in various asymmetries, which were not observed in Comparative Examples 1 to 3.

[0126] a) Surface roughness In Examples 1 to 2, the second surface had a significantly reduced surface roughness R a compared to the first surface, and in contrast, this difference was not observed in the comparative examples. The surface roughness R a was measured by an atomic force microscope (AFM). Model: Dimension Icon by BRUKER. Area: 10×10 μm. The surface roughness R a was specified in accordance with DIN EN ISO 4287:2010-07.

[0127] b) Chamfer asymmetry The chamfer structures of Examples 1 to 3 were very asymmetric. In contrast, such asymmetry was not observed in the comparative examples.

[0128] The symmetry / asymmetry of the chamfered structure was evaluated as shown in Figures 1-3, based on cross-sectional images of the chamfered structure profiles shown in Figure 3. To obtain such images, the glass articles were observed in transmitted light mode using an optical microscope. A magnification of 200x was used. The focal point was on the top surface, so the edges appeared very sharp. The glass articles were positioned so that the top surface was not tilted. Therefore, the top surface was perpendicular to the direction of light. Particularly good quality images were obtained using a Nikon Y-TV55 microscope with automatic white balance, automatic brightness, and automatic contrast.

[0129] As illustrated in Figure 3, in the microscope images, the tangents were fitted to the corresponding surfaces (tangent A to the first connecting surface, tangent B to the first surface, tangent C to the perpendicular surface, tangent D to the second connecting surface, and tangent E to the second surface). The fitting of the tangents to each surface was performed manually using ImageJ software.

[0130] As shown in Figure 3, tangent A to the first connecting surface intersects tangent B to the first surface at a distance d1 from tangent C to the vertical surface. Similarly, tangent D to the second connecting surface intersects tangent E to the second surface at a distance d2 from tangent C to the vertical surface. Both d1 and d2 were measured perpendicular to tangent C to the vertical surface, as also shown in Figure 3. The lengths of distances d1 and d2 were measured using ImageJ software by comparing the lengths of distances d1 and d2 to the lengths of scale bars, respectively.

[0131] The asymmetry values ​​referenced in the table above are the absolute values ​​of the difference d1-d2. For Examples 1-3, this difference was 40-64 μm, respectively. In contrast, for the comparative example, this difference was less than 10 μm.

[0132] c) chemical strengthening The asymmetry of the glass article of the present invention with respect to the first and second surfaces is also reflected by the asymmetry during chemical strengthening.

[0133] As shown in the table above, the first surface of Examples 1 to 3 is associated with a higher surface compressive stress (CS) but a lower compressive stress layer depth (DoL) compared to the second surface of the glass article. Such a difference was not observed in the comparative examples.

[0134] Interestingly, the difference between the first and second surfaces regarding the chemical strengthening results was correlated with the occurrence of warping in Examples 1-3, as shown in the table above. Warping was not observed in the comparative examples. Warping was measured by placing the glass article on a flat surface and then recording the longest distance of the lower surface of the glass article from the flat surface as the warp. This is typically at one of the four corners. The distance was measured using a set of feeler gauges (resolution was 0.02 mm). The warping data shown in the table above is for the entire sample area, i.e., 40 × 125 mm each. 2 or 30 x 50 mm 2 Regarding.

[0135] The warping in Examples 1 to 3 involved a first surface of the glass article being convex and a second surface of the glass article being concave.

[0136] d) Pen drop height The fracture height is determined in a pen drop test, in which the glass article is mounted on one surface of a 150 μm thick substrate, which consists of a 25 μm thick layer of pressure-sensitive adhesive (PSA) material, a 50 μm thick layer of polyethylene (PE), another 25 μm thick layer of pressure-sensitive adhesive (PSA), and another 50 μm thick layer of polyethylene (PE), from the side in contact with the glass to the side in contact with the marble stage. Beneath the 150 μm thick substrate is a flat, 10 cm thick marble stage with a polished, smooth surface. Subsequently, the other surface of the glass article, facing upwards, is struck with a 14 g ballpoint pen (manufactured by Chenguang) with a tungsten carbide ball diameter of 0.5 mm, increasing the height from 5 mm until the glass breaks. The fracture height is then recorded as the pen drop height.

[0137] The product of a pen drop test is the pen drop height on a surface impacted by a ballpoint pen. Since the pen drop height is significantly dependent on the thickness of the article, it may be considered to refer to a normalized pen drop height to compare the properties of articles of different thicknesses. The normalized pen drop height is calculated by dividing the pen drop height (μm) by the square of the article's thickness (μm). 2 The result was obtained as a ratio to ). The results are shown in the table below.

[0138] [Table 2]

[0139] The pen drop height values ​​in the table above are the average values ​​from 15 experiments. The standard deviations were 1.2 mm for Example 1, 1.3 mm for Example 2, and 2.2 mm for Example 3.

[0140] The data shows a significant increase in pen drop height on the first surface. In contrast, the pen drop height of the comparative examples was comparable to that of the second surface in Examples 1-3 (Comparative Example 1: 12.9 mm, Comparative Example 2: 6.1 mm, Comparative Example 3: 39.5 mm).

[0141] e) 2PB strength In a two-point bending test (2PB test), a glass article is placed in a U-shape between two parallel metal plates. The two plates are large enough to cover the entire glass article. Then, one of the plates is moved toward the other at a speed of 60 mm / min while maintaining parallelism until the glass article breaks. The 2PB strength is σ = 1.198Ed / (Dd) The formula is calculated by, where σ is the calculated strength, E is Young's modulus, d is the thickness of the glass article, and D is the distance between the two plates at the time of fracture.

[0142] The product of the 2PB test is the 2PB strength of the glass article surface that was the outer surface of the bend. For example, if a glass article is bent such that the second surface is the outer surface of the bend and the first surface is the inner surface of the bend, the product of the 2PB test is the 2PB strength of the second surface of the glass article.

[0143] The table below shows the 2PB strength (MPa) for Examples 1 to 3 in the 2PB test.

[0144] [Table 3]

[0145] The 2PB strength values ​​in the table above are the average values ​​from 30 experiments. The data shows that the 2PB strength of the second surface was significantly increased by protecting the second surface from the etching solution during the slimming stage. In contrast, this was not observed in the comparative examples because the second surface was not protected. In fact, the 2PB strength of the comparative examples was equivalent to that of the first surface in Examples 1 to 3 (Comparative Example 1: 2570 MPa, Comparative Example 2: 2438 MPa, Comparative Example 3: 2451 MPa).

[0146] f) Ball-on-Ring (BoR) Test In the BoR test, a glass object is placed on a steel ring having an inner diameter of 4 mm and an outer diameter of 6 mm. The ring is 3 mm deep, with a wall thickness of 1 mm, and the ends of the walls have a semicircle with a cross-section of 1 mm in diameter. The ends of the glass specimen were at least 20 mm away from the center of the ring. A 1 mm diameter tungsten carbide ball is then pressed against the glass specimen along the central axis of the ring at a speed of 5 mm / min until the glass closes. The force at fracture is recorded. The setup of the BoR test is schematically shown in Figure 4.

[0147] Depending on which surface of the glass article is in contact with the ring or ball, the ball-on-ring breaking force of the first or second surface of the glass article can be tested. The ball-on-ring test described herein is adapted to determine the ball-on-ring breaking force of a specific surface of a glass article in contact with a steel ring. In particular, it is this surface of the glass article where tensile stress is generated 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 in contact with the steel ring.

[0148] The table below shows the BoR destructive force (N) for Examples 1 to 3 in the BoR test.

[0149] [Table 4]

[0150] The BoR breaking force values ​​in the table above are the average values ​​from 15 experiments. The data shows that protecting the second surface from the etching solution during the slimming stage significantly increased the BoR breaking force of the second surface. In contrast, this was not observed in the comparative examples because the second surface was not protected. In fact, the BoR breaking force of the comparative examples was equivalent to the BoR breaking force of the first surface in the corresponding Examples 1 to 3 (Comparative Example 1: 9.3N, Comparative Example 2: 8.2N, Comparative Example 3: 12.6N). [Explanation of symbols]

[0151] 10, 20 Glassware 11, 21 First surface 12, 22 Second surface 13, 23 vertical surface 14, 24 First connecting surface 15, 25 Second connection surface 16, 26 Chamfered structure 41 Glassware 42 rings 43 Ball 44, 45 Surface of glass articles

Claims

1. A glass article having a thickness of 10 μm to 150 μm, - Includes a first surface, a second surface, and at least one end connecting the first surface and the second surface, - Surface roughness R of the second surface a The (arithmetic mean roughness) is a maximum of 0.30 nm. The ratio of DoL2 / DoL1 is greater than 1.00 and in the range up to 1.20, where DoL1 is the layer depth of the compressive stress layer extending from the first surface toward the center of the glass article, and DoL2 is the layer depth of the compressive stress layer extending from the second surface toward the center of the glass article. - The glass article is chemically strengthened. The aforementioned glass article.

2. Surface roughness R of the first surface a The glass article according to claim 1, wherein the maximum is 0.80 nm.

3. Surface roughness R of the first surface a However, the surface roughness R of the second surface a A glass article according to claim 1 or 2, which is higher than the above.

4. Surface roughness R of the first surface a And the surface roughness R of the second surface a The glass article according to any one of claims 1 to 3, wherein the absolute value of the difference is at least 0.05 nm.

5. The first surface and the second surface are essentially parallel to each other, The aforementioned end has the following three surfaces: - A vertical surface that is essentially perpendicular to the first surface and the second surface, - A first connecting surface that connects the vertical surface and the first surface, and - A second connecting surface that connects the vertical surface and the second surface. It has a chamfered structure including, - The chamfered structure is - The tangent A to the first connecting surface is at a distance d from the tangent C to the vertical surface. 1 At this point, it intersects with the tangent line B to the first surface, and - The tangent D to the second connecting surface is at a distance d from the tangent C to the vertical surface. 2 At this point, it intersects with the tangent line E to the second surface. Having a profile, here -d 1 and d 2 Both are measured perpendicular to the tangent line C to the vertical surface, - Tangents A to E are obtained by fitting each tangent to the corresponding surface in the profile of the chamfered structure. - The chamfered structure is d 1 ≠d 2 It is asymmetrical in that way. The glass article according to claim 1.

6. Difference d 1 -d 2 The glass article according to claim 5, wherein the absolute value of is at least 30% of the thickness of the glass article.

7. Difference d 1 -d 2 The glass article according to claim 5 or 6, wherein the absolute value of is up to 200% of the thickness of the glass article.

8. Difference d 1 -d 2 The glass article according to any one of claims 5 to 7, wherein the absolute value of is at least 15 μm.

9. Difference d 1 -d 2 The glass article according to any one of claims 5 to 8, wherein the absolute value of is a maximum of 100 μm.

10. d 1 A glass article according to any one of claims 5 to 9, wherein the thickness is in the range of 50 to 200 μm.

11. d 2 A glass article according to any one of claims 5 to 10, wherein the thickness is in the range of 30 to 100 μm.

12. d 1 ga d 2 A glass article according to any one of claims 5 to 9, which is larger than the glass article.

13. The first surface has impact resistance corresponding to a pen drop height of at least 5 mm, The second surface has a ball-on-ring breaking force of at least 5.0 N and / or a two-point bending strength of at least 2,000 MPa. The glass article according to claim 1.

14. The glass article according to any one of claims 1 to 13, wherein the first surface has impact resistance corresponding to a normalized pen drop height of at least 4.5 per 1 μm.

15. The glass article according to any one of claims 1 to 14, wherein the ratio of the pen drop height on the first surface to the pen drop height on the second surface is at least 1.

05.

16. The glass article according to any one of claims 1 to 15, wherein the ratio of the ball-on-ring breaking force of the second surface to the ball-on-ring breaking force of the first surface is at least 1.

05.

17. The glass article according to any one of claims 1 to 16, wherein the ratio of the two-point bending strength of the second surface to the two-point bending strength of the first surface is at least 1.

05.

18. The glass article according to any one of claims 1 to 17, wherein each of the surface compressive stress CS1 on the first surface of the glass article and the surface compressive stress CS2 on the second surface of the glass article is at least 300 MPa.

19. The glass article according to claim 18, wherein each of CS1 and CS2 is a maximum of 1000 MPa.

20. The glass article according to claim 18 or 19, wherein the surface compressive stress CS1 on the first surface is higher than the surface compressive stress CS2 on the second surface.

21. The glass article according to any one of claims 18 to 20, wherein the absolute value of the difference CS1 - CS2 is at least 10 MPa.

22. A glass article according to any one of claims 19 to 21, wherein the absolute value of the difference CS1 - CS2 is a maximum of 100 MPa.

23. The glass article according to any one of claims 1 to 22, wherein the article has a first compressive stress layer extending from a first surface of the glass article to a first layer depth DoL1 and a second compressive stress layer extending from a second surface to a second layer depth DoL2, and each of DoL1 and DoL2 is in the range of 2.5 to 20.0 μm and / or in the range of 5.0% to 40.0% of the thickness of the glass article.

24. A glass article according to any one of claims 1 to 23, having a curvature of 5 mm or less.

25. A glass article according to any one of claims 1 to 24, having a curvature of 0.5 mm or more.

26. The glass article is 1 mm 2 A glass article according to any one of claims 1 to 25, having an area relative curvature in the range of 0.02 to 5.0 μm per unit area.

27. The glass article according to any one of claims 1 to 26, wherein the glass article has a relative curvature in the range of 5.0 to 50.0 μm per 1 mm.

28. The glass article according to any one of claims 24 to 27, wherein the first surface of the glass article is a convex surface and the second surface of the glass article is a concave surface.

29. A method for manufacturing a glass article according to any one of claims 1 to 28, the following steps: a) The stage of preparing multiple glass articles, b) The step of forming a stack assembly comprising the plurality of glass articles and at least one adhesive layer between two adjacent glass articles, wherein a first surface of a glass article is in contact with a first type of adhesive and a second surface of a glass article is in contact with a second type of adhesive, c) The step of bringing the stack assembly or a smaller stack assembly obtained therefrom into contact with the first etching solution. d) The step of delayering the stack assembly or a smaller stack assembly obtained therefrom by removing the first type of adhesive, wherein a sandwich assembly is obtained consisting of two glass articles and a second type of adhesive located between the two glass articles. e) The step of bringing the sandwich assembly into contact with the second etching solution, f) The step of delayering the sandwich assembly by removing the second type of adhesive, The method, including the method described above.

30. The method according to claim 29, wherein the first type of adhesive and / or the second type of adhesive is a UV-curing adhesive.

31. The method according to claim 29 or 30, wherein step d) includes holding the stack assembly or a smaller stack assembly obtained therefrom in an absorptive liquid at a temperature above 40°C.

32. The method according to claim 31, wherein the stack assembly or a smaller stack assembly obtained therefrom is held in an absorptiating liquid for 1 to 30 minutes.

33. The method according to any one of claims 29 to 32, wherein the second etching solution contains HF.

34. The method according to any one of claims 29 to 33, wherein step f) includes applying UV irradiation to the sandwich assembly.

35. UV irradiation intensity 200-1000 mJ / cm 2 The method according to claim 34, which is applied for 30 seconds to 30 minutes.

36. The method according to any one of claims 29 to 35, further comprising the step of chemically strengthening the glass article obtained by the abscission step f).

37. The method according to any one of claims 29 to 36, wherein the method includes a step of cutting the stack assembly formed in step b) to obtain a smaller stack assembly, the cutting step being performed before step c).

38. The method according to any one of claims 29 to 37, further comprising the step of grinding the edges of the stack assembly or a smaller stack assembly obtained therefrom before contacting the stack assembly with the first etching solution of step c).

39. A bending device including a glass article as described in any one of claims 1 to 28.

40. The bendable device according to claim 39, wherein the device can be bent such that the first surface is located on the inner surface of the bend and the second surface is located on the outer surface of the bend.

41. The bending device according to claim 39 or 40, wherein the device can be bent to a bending radius of 1 mm to 5 mm.

42. The bendable device according to any one of claims 39 to 41, wherein the device is an electronic device, particularly a smartphone.

43. Use of a glass article according to any one of claims 1 to 28 in a bendable device, in particular a bendable electronic device, such as a smartphone.

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