Method for manufacturing partially textured glass articles

Abstract

The present invention provides a method for manufacturing at least partially textured glass articles, the method comprising, in order: a) providing a partially textured mother glass substrate having first and second major surfaces facing each other; b) irradiating at least the first major surface of the glass substrate with a laser to form at least one separation line on the first major surface for separating at least one glass article from the glass substrate, wherein the at least one separation line defines a contour line and extends in a depth direction from the first major surface to the second major surface, and the glass article has a size smaller than that of the mother glass substrate; and c) separating the at least one partially textured glass article from the mother glass substrate according to the at least one separation line. The present invention enables a large partially textured mother glass substrate to be cut with high precision into smaller partially textured glass articles of required sizes.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a glass article that is partially textured. In particular, the present invention relates to an improved method for manufacturing a glass piece that is partially textured and has a required size from a larger mother glass substrate that is partially textured.

Background Art

[0002] In the fields of cover glass for electronic devices, window glass for building materials, and window glass for vehicles, fragments of glass sheets are required that have a specific size (sometimes a small size) and exhibit a specific roughness / texture only on a part of some of their main surfaces, i.e., in the form of several types of features / patterns / zones. For example, small glass pieces that are partially textured can be used as (touch) screens for a number of electronic devices such as protective / cover glass, peepholes, or mobile phones, smartphones, TVs, computers, digital cameras, etc. These can also be used as window glass inside automobiles such as trim elements or consoles.

[0003] When features / zones that are textured using any well-known method are repeatedly formed on a large mother glass substrate (i.e., up to the PLF size or DLF size at most), in order to obtain smaller fragments having the textured features, it is necessary to cut the sheet in the thickness direction at a later stage. However, for the intended uses of such glass pieces that are partially textured, the position of the textured features / zones on each manufactured glass piece is required to be very precise. Unfortunately, the accuracy shown by the methods generally used for cutting glass in the thickness direction, particularly the method of cutting a large sheet into several small fragments, is too low (about 0.2 to 2 mm). These methods are, for example, the method of using a cutting wheel having a sharp peripheral edge, the method of using a water jet, or the method of using a saw.

[0004] Another solution for manufacturing small pieces of partially textured glass involves first cutting a large mother glass substrate into smaller pieces of the appropriate final size, and then forming a given textured pattern / area on each of those smaller pieces. However, such a solution is not economically viable due to reasons such as handling and time.

[0005] Therefore, for the aforementioned applications, it is necessary that a method be available for cutting a large mother glass substrate having a repeating textured pattern / area into smaller fragments with high precision, wherein the pattern / area can be precisely positioned on each individual element.

[0006] Furthermore, for the intended applications (displays, automotive interiors, etc.), the final small glass pieces generally need to be strengthened, for example, by chemical strengthening treatment, to meet safety requirements. In fact, the glass used in such applications has many mechanical requirements and is therefore very desirable to be able to withstand damage such as scratches or impacts during use and transport.

[0007] Chemical strengthening is a heat-induced ion exchange process that involves replacing smaller alkali ions, such as sodium or lithium, in the surface layer of glass with larger ions, such as alkali potassium ions. The larger ions "wedge" into the smaller areas previously occupied by sodium ions, increasing the compressive stress on the glass surface and thereby improving the strength of the glass substrate. Such chemical treatment is generally carried out by immersing the glass in an ion-exchange molten bath containing one or more molten salts of the larger ions, with strict control of temperature and time.

[0008] Therefore, this would be very useful even if the high-precision cutting method being sought also involves glass strengthening (especially chemical strengthening) before the mother substrate is divided into smaller pieces.

[0009] Generally, chemically strengthened glass fragments are obtained from a larger mother glass substrate by (i) cutting and collecting multiple glass fragments of the required size from the mother glass substrate, and (ii) chemically strengthening each glass fragment. In this conventional method, smaller glass fragments, which have low mechanical resistance and are prone to scratching, are handled before chemical strengthening takes place in a later stage. To avoid this problem, several methods have been developed, such as strengthening the larger mother glass before the cutting step. However, in such methods, the end faces / edges of the smaller glass fragments are not strengthened (similar to when they are processed individually after cutting). Therefore, the final glass fragments have little mechanical resistance at their edges and cannot meet safety requirements. [Overview of the project] [Problems that the invention aims to solve]

[0010] The present invention aims, in particular, to overcome the aforementioned drawbacks of existing methods.

[0011] In particular, an object of the present invention is to provide a method for manufacturing partially textured glass pieces of a required size from a larger partially textured mother glass substrate. In particular, one object of the present invention is to provide a high-precision method for manufacturing partially textured glass pieces of a required size from a larger mother glass substrate having repeating textured patterns / areas.

[0012] Another objective is to provide a method for manufacturing partially textured glass pieces of a required size from a larger partially textured mother glass substrate, where it is appropriate to perform glass strengthening treatment before the mother glass substrate is divided into smaller pieces.

[0013] Another object of the present invention is to provide a simple, efficient, and less expensive method for manufacturing a partially textured glass piece of a required size from a larger partially textured mother glass substrate. [Means for solving the problem]

[0014] The present invention relates to a method for manufacturing a glass article that is at least partially textured, wherein the method is performed in the following order: a) A step of providing a partially textured mother glass substrate having a first main surface and a second main surface facing each other, b) A step of irradiating at least a first main surface of a glass substrate with a laser to form at least one separation line on the first main surface for separating at least one glass article from the glass substrate, wherein the at least one separation line defines a contour line and extends in the depth direction from the first main surface to the second main surface, and the glass article has a size smaller than the size of the mother glass substrate, and c) Step of separating at least one partially textured glass article from a mother glass substrate according to at least one separation line. Regarding methods including

[0015] Therefore, the present invention lies in a novel and inventive method, as it is possible to find solutions to the shortcomings of the prior art. In fact, the inventors have found that by using such a method, a larger partially textured mother glass substrate having a repeating pattern can be cut with high precision into smaller fragments / articles of partially textured glass of the required size. In particular, the proposed method allows for very good relative positioning of the cutting line with respect to the textured features, and can ensure the correct position of the features on the smaller cut glass pieces. Furthermore, the proposed method is very advantageous because the contour / edge of the textured feature can be used as a reference for the laser (or even further, the reference mark can be integrated into the textured feature).

[0016] Throughout this specification, where a range is indicated, the values ​​at both ends are included. Furthermore, all integer values ​​and values ​​within sub-ranges of that numerical range are included as explicitly stated. [Brief explanation of the drawing]

[0017] Other features and advantages of the present invention will become more apparent from the following description of preferred embodiments and figures (1 and 2), which are shown merely as descriptive and non-limiting examples.

[0018] [Figure 1] This diagram schematically shows the flow of the method according to the present invention. [Figure 2] Several configurations of partial textures and separator lines are schematically shown. [Modes for carrying out the invention]

[0019] According to the present invention, the mother glass substrate and the glass article are partially textured.

[0020] In the present invention, "partially textured" means that the glass has at least one area on its surface having a different roughness compared to the remaining part of the surface. Generally, the roughness of the glass can be evaluated by the arithmetic amplitude value Ra. According to the present invention, that area 1 has an increased roughness compared to area 2 means that Ra1 - Ra2 ≧ 25 nm (preferably ≧ 30 nm or even ≧ 50 nm, more preferably ≧ 75 nm or even ≧ 100 nm), where Ra1 is the arithmetic amplitude value of area 1 and Ra2 is the arithmetic amplitude value of area 2.

[0021] To completely avoid uncertainty, according to the present invention, the term "partially textured" glass substrate or glass article includes embodiments where the substrate / article exhibits a plurality of areas of different roughness (i.e., over its entire area).

[0022] According to the present invention, the partial texture can be present on the first major surface or the second major surface or both major surfaces.

[0023] According to the present invention, the texture can be formed by any well-known method such as chemical etching (i.e., the use of HF and / or fluoride compounds) or sandblasting, such as the removal of material from a smooth glass surface. Chemical etching is preferred because it can achieve a roughness appropriate for the intended application and, as a result, the optical properties and aesthetics.

[0024] According to the present invention, the partial texture can be formed by any well-known method capable of selectively texturing the glass surface, thereby forming the textured area. For example, when considering the formation of the texture according to the present invention by chemical etching, a well-known method using a protective mask resistant to the chemical etching treatment can be used, whereby only specific parts / areas of the glass surface can be exposed to the etching treatment, which will be removed later. The etched texture area obtained on the glass surface as a result corresponds to the negative of the pre-attached mask.

[0025] In the present invention, as shown in FIG. 2, the partial texture on the mother glass substrate (1) can advantageously be in the form of a repeating pattern, and each individual pattern (2) corresponds to the partial texture, which is present on the glass article after separation from the mother glass substrate. The pattern (2) on the mother glass substrate can be periodically repeated in one direction of its surface (see FIG. 2(b)), or can be repeated in both directions of its surface (see FIG. 2(a)).

[0026] Each individual pattern (2) - is composed of one textured area (and thus one non-textured or less textured area resulting therefrom) - FIGS. 2(a), (c); or - is composed of several textured areas - FIG. 2(b) can be either of these.

[0027] In the present invention, according to the separation line (3), each individual pattern (2) from the mother glass substrate (1) can be obtained on the final glass article, the number of which corresponds to the number of times the pattern repeats on the mother glass substrate.

[0028] In another embodiment, the mother glass substrate is chemically strengthened after irradiation step b) and before separation step c). This embodiment is advantageous because it can strengthen the glass articles not only on their main surfaces but also on their edges. Thus, the glass articles become more resistant to scratches and mechanical stress / loads. According to this embodiment, after chemical strengthening of the mother glass substrate, (i) the potassium levels on the first and second main surfaces of the glass articles are higher than the potassium levels on the edges of the glass articles, and (ii) the potassium levels on the edges of the glass articles are higher than the potassium levels on the glass articles as a whole. As the potassium levels on the end faces of the glass articles increase during chemical strengthening, they become more resistant to external load stresses.

[0029] The conditions for chemical strengthening are not particularly limited in this invention. Chemical strengthening can be performed, for example, by immersing a mother glass substrate in a molten salt at 380°C to 500°C for 1 minute to 72 hours. Nitrates can be used as the molten salt. For example, when exchanging lithium ions contained in the glass substrate for larger alkali metal ions, a molten salt containing at least one of sodium nitrate, potassium nitrate, rubidium nitrate, and cesium nitrate can be used. Furthermore, when exchanging sodium ions contained in the glass substrate for larger alkali metal ions, a molten salt containing at least one of potassium nitrate, rubidium nitrate, and cesium nitrate can be used. Furthermore, when exchanging potassium ions contained in the glass substrate for larger alkali metal ions, a molten salt containing at least one of rubidium nitrate and cesium nitrate can be used. In addition, one or more salts such as potassium carbonate can be further added to the molten salt. In this case, a low-density layer having a thickness of 10 nm to 1 μm can be formed on the surface of the mother glass substrate.

[0030] By performing a chemical strengthening treatment on a mother glass substrate having at least one separation line defining the contour of at least one glass article, a compressive stress layer can be formed on the first and second main surfaces of the glass substrate and at the edges of the glass article. The thickness of the compressive stress layer corresponds to the penetration depth of the substituted alkali metal ions. For example, when sodium ions are exchanged for potassium ions using potassium nitrate, the thickness of the compressive stress layer can be 5 μm to 50 μm in the case of soda-lime glass, and 10 μm to 100 μm in the case of aluminosilicate glass. In the case of aluminosilicate glass, the penetration depth of the alkali metal ions is preferably 10 μm or more, more preferably 20 μm or more.

[0031] According to one embodiment, advantageously, the method may further include a cold bending step after the separation step c). Cold bending is particularly valued in the case of bending glass articles of interior and exterior window glass parts of automobiles, such as glass consoles, dashboards, door trim elements, pillars, windshields, side windows, rear windows, sunroofs, and partition walls.

[0032] According to the present invention, in step b), a laser is irradiated onto the mother glass substrate to form at least one separation line.

[0033] According to one embodiment of the present invention, the separation line extends in the depth direction from one main surface to the opposite main surface.

[0034] Preferably, a laser is irradiated onto the glass substrate to form at least one separation line on at least the first main surface of the glass substrate as a "spot cutting line" defined by lines of multiple voids formed by the laser.

[0035] Therefore, it will be understood that the depth of the void is determined by the thickness of the glass. More preferably, the depth of the void is equal to the thickness of the mother glass substrate.

[0036] Here, "separation line" refers to a linear or curved region formed by arranging multiple void lines in a predetermined sequence. Preferably, the depth of the multiple void lines corresponds to the thickness of the mother glass substrate in order to easily and properly separate at least one glass article from the glass substrate.

[0037] The required void depth depends on the thickness of the glass substrate and / or the shape and / or size of the glass article, but can be obtained by exposing the first main surface of the glass substrate to a laser, or by exposing the first and second main surfaces of the glass substrate to a laser, or by exposing the first main surface of the glass substrate to multiple sets of laser beams in a continuous manner.

[0038] The predetermined arrangement of "separation lines" is, for example, a plurality of surface voids arranged in a fixed direction (X direction) on the first main surface of the glass substrate, thereby forming an in-plane void region.

[0039] Each surface void corresponds to at least the laser irradiation position on the first main surface and has a diameter of, for example, 1 μm to 5 μm. However, the diameter of the surface voids varies depending on the laser irradiation conditions, the glass substrate, etc.

[0040] The distance between the centers of adjacent surface voids is determined based on the composition and thickness of the glass substrate, laser processing conditions, the shape and / or size of the glass article, etc. For example, the distance between the centers of adjacent surface voids can be in the range of 2 μm to 10 μm. It should be noted that the distance between the centers of surface voids does not need to be equal at all locations and can vary from place to place, and the voids can be arranged at irregular intervals.

[0041] On the other hand, as mentioned above, multiple void lines (spot cutting lines) can be formed by arranging one or more voids in the glass substrate from the first main surface to the second main surface.

[0042] The shape, size, and pitch of the voids are not particularly limited. For example, the voids can have shapes such as circles, ellipses, rectangles, or triangles when viewed from the Y direction. Furthermore, the maximum dimension of the voids when viewed from the Y direction is, for example, in the range of 0.1 μm to 1000 μm.

[0043] According to one embodiment of the present invention, the voids constituting at least one separation line are arranged along the thickness direction (Z direction) of the glass substrate. Preferably, each void of the separation line extends in the Z direction. However, each void constituting at least one separation line may be arranged at an angle with respect to the Z direction from a first main surface to a second main surface of the glass substrate. The at least one separation line constituting the separation line may or may not have a void (second surface void) that is open to the second main surface opposite to the first main surface of the glass substrate.

[0044] Therefore, as mentioned above, the separation line is not formed as a continuous "line," but rather as a virtual void region formed when the respective surface voids are connected. It should be noted that this represents a linear region.

[0045] Furthermore, the separating line can be composed of multiple single parallel lines placed very close together, forming a single aggregate of multiple parallel lines.

[0046] According to one advantageous embodiment of the present invention, the laser is a filament cutting laser or a green laser. Preferably, the laser is a filament laser because it can increase the speed of the method.

[0047] A suitable laser for the method according to the present invention is, for example, a short-pulse laser. Such a short-pulse laser beam is preferably a burst pulse that efficiently forms gaps constituting at least one separation line. Furthermore, the average power output of such a short-pulse laser over irradiation time is, for example, 30 W or more. If this average power output of the short-pulse laser is less than 10 W, sufficient gaps may not be formed in some cases. As an example of a burst-pulse laser beam, one row of internal gaps is formed by a burst laser with 3 to 10 pulses, the laser power is about 90% of the rated power (50 W), the burst frequency is about 60 kHz, and the burst duration is 20 picoseconds to 165 nanoseconds. A preferred range for the burst duration is 10 nanoseconds to 100 nanoseconds.

[0048] If multiple separation lines are formed on the first main surface, the separation lines can be formed in one step or in two or more steps. The separation lines are determined by the desired size of the glass article (i.e., the final product). The contour of the glass article is defined by the separation lines from the larger size mother glass substrate. Thus, after step b), the glass article is separated and collected from the larger size mother glass substrate according to the separation lines / contour lines.

[0049] According to one embodiment of the present invention, separation lines and, in particular, a plurality of adjacent voids are formed from the upper surface of the glass substrate. The term “upper surface of the glass substrate” is understood to be the surface of the glass substrate that does not directly contact the support when the glass substrate is placed on the support to form separation lines.

[0050] According to one embodiment of the present invention, the separation line and, in particular, the plurality of parallel voids are formed from the upper surface (first main surface) and the lower surface (second main surface) of the glass substrate. According to this embodiment, the first main surface of the glass substrate can be irradiated with a laser first, and then the second main surface can be irradiated. Furthermore, according to this embodiment, separately from this, the first and second main surfaces can be irradiated simultaneously.

[0051] According to one embodiment of the present invention, separation lines defining a contour line for separating at least one glass article from a mother glass substrate may exist internally and / or externally. An external separation line means a separation line in which at least one end reaches one edge of the mother glass sheet. An internal separation line means a separation line that does not reach an edge of the mother glass sheet.

[0052] The required depth for the gaps that make up the separation line can be obtained by repeatedly performing laser operations that pass through the thickness of the glass substrate.

[0053] In step c) of the proposed method of the present invention, the glass article is separated from the mother glass substrate. Various methods are possible to perform this separation. One solution is to initiate a crack at a controlled location using a mechanical device (diamond tool, cutting wheel, etc.) so that the crack propagates along the initial separation line. Furthermore, by forming additional voids near the initial separation line, controlled crack propagation along the initial separation line occurs. In fact, these first methods utilize the internal stress in the center of the glass panel generated by the chemical strengthening process. Thus, the initiation of the initial crack at the appropriate location induces the separation of the glass article from the initial glass panel. Even if the initial glass panel is destroyed from the final glass article, it is possible to obtain the final glass article without affecting its quality. Another technique for separating the glass article from the mother glass substrate is to promote the cracking of the separation line by inducing thermal shock with either heating using a CO2 laser spot, flame, or IR heater, or cooling using compressed air, liquid nitrogen, or other coolant. Also, the cracking of the glass article can be induced by pouring an acidic solution (etching solution) onto multiple parallel voids.

[0054] According to the present invention, the glass composition of the mother glass substrate is not particularly limited, as long as its composition is suitable for chemical strengthening. The glass substrate may be, for example, soda-lime glass, aluminosilicate glass, alkali-aluminosilicate glass, etc. The glass substrate according to the present invention may be a glass substrate obtained by the float process, the pull-up process, the rolling process, or any other well-known method for producing glass sheets starting from a molten glass composition. According to one preferred embodiment of the present invention, the glass substrate is a float glass substrate. It should be understood that the term “float glass substrate” means a glass substrate formed by the float glass process, which involves pouring molten glass onto a molten tin bath under reducing conditions.

[0055] The mother glass substrate according to the present invention is made of glass whose matrix composition is not particularly limited and can therefore belong to various classifications. The glass can be soda-lime silicate glass, aluminosilicate glass, alkali-free glass, borosilicate glass, etc. Preferably, the glass substrate of the present invention is made of soda-lime glass or aluminosilicate glass.

[0056] According to one embodiment of the present invention, the glass substrate contains, in a percentage of the total weight of the glass, SiO255~85% Al2O30-30% B2O 30-20% Na2O 0-25% CaO 0-20% MgO 0-15% K2O 0-20% BaO 0-20% It has a composition that includes the following:

[0057] In a preferred embodiment, the glass substrate is contained in a percentage of the total weight of the glass, SiO255~78% Al2O30~18% B2O 30-18% Na2O 5-20% CaO 0-10% MgO 0-12% K2O 0-12% BaO 0-5% It has a composition that includes the following:

[0058] In a more preferred embodiment, the glass substrate is contained in a percentage of the total weight of the glass, SiO2 60-78% Al2O30~8% B2O 30-4% CaO 0-10% MgO 0-12% Na2O 5-20% K2O 0-12% BaO 0-5% It has a composition that includes the following:

[0059] In the most preferred embodiment, the glass substrate is contained in a percentage of the total weight of the glass, 60 ≤ SiO2 ≤ 78% 5 ≤ Na₂O ≤ 20% 0.9 <K2O≦12% 4.9 ≤ Al2O3 ≤ 8% 0.4 <CaO<2% 4 <MgO≦12% It has a composition that includes the following:

[0060] The mother glass substrate according to the present invention can have a thickness of 0.03 to 19 mm. Advantageously, the mother glass substrate according to the present invention can have a thickness of 0.03 mm to 6 mm. Preferably, for weight reasons and to facilitate cold bending of the glass article as needed, the thickness of the mother glass substrate can be 0.1 to 2.2 mm.

[0061] According to the present invention, the mother glass substrate can be flat or curved entirely or partially, that is, it can be curved entirely or partially to suit the individual design of the final glass article and / or support when cold bending of the glass article is required.

[0062] The present invention also relates to glass articles obtained by the method described above.

[0063] The present invention relates to a partially textured glass article, - An angle formed between the first and second principal surfaces, each equal to 90° ± 7°; - Surface roughness defined by Ra of 0.1 to 1 micron, measured along a line at a point equal to half the sheet thickness (i.e., sheet thickness / 2). The invention also relates to glass articles characterized by having at least one edge that indicates [a specific characteristic].

[0064] Finally, the present invention relates to a partially textured glass article, (i) The potassium levels on the first and second main surfaces of the glass article are higher than the potassium levels on the edges of the glass article, (ii) The level of potassium at the edge of the glass article is higher than the overall level of potassium in the glass article, also relating to the glass article.

[0065] As the potassium level increases at the edges of an article, the edges become more mechanically resistant.

[0066] The glass articles according to the present invention are particularly suitable as interior window glass for vehicles, such as consoles and dashboards, exterior windows for vehicles, and glass trim elements, where more complex shapes are required by automobile manufacturers. In particular, these glass articles are very suitable as glass consoles, dashboards, or trim elements for vehicles.

Claims

1. A method for manufacturing at least one partially textured glass article, wherein the at least one partially textured glass article is a glass console, dashboard, exterior window of a vehicle, or glass trim element, and the method is performed in the following order: a) Providing a partially textured mother glass substrate having a first main surface and a second main surface facing each other, b) A step of irradiating at least the first main surface of the mother glass substrate with a laser to form at least one separation line on the first main surface for separating at least one glass article from the mother glass substrate, wherein the at least one separation line defines a contour line and extends in the depth direction from the first main surface to the second main surface, the glass article has a size smaller than the size of the mother glass substrate, and the at least one separation line includes a plurality of adjacent voids that form a spot cutting line, and c) Separating the at least one partially textured glass article from the mother glass substrate according to the at least one separation line. Methods that include...

2. The method according to claim 1, characterized in that the mother glass substrate is chemically strengthened between step b) and step c).

3. - The potassium levels on the first and second main surfaces of the at least one partially textured glass article are higher than the potassium levels on the edges of the at least one partially textured glass article, The method according to claim 2, characterized in that the level of potassium at the edge of the at least one partially textured glass article is higher than the level of potassium in the entire at least one partially textured glass article.

4. The at least one partially textured glass article, - An angle formed between the first and second main surfaces, each equal to 90° ± 7°; and - Surface roughness defined by Ra of 0.1 to 1 micron, measured at a position along the line at sheet thickness / 2. The method according to any one of claims 1 to 3, characterized in that it has at least one edge indicating [something].

5. The method according to any one of claims 1 to 4, characterized in that the thickness of the at least one partially textured glass article is in the range of 0.03 to 19 mm.

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