Glass sheet production method

Abstract

To cut a glass sheet without forming any initial crack.SOLUTION: This glass sheet production method includes a fusion-cutting step in which laser light L is radiated along a closed-loop-shaped planned cut line CL provided on a glass sheet MG to fusion-cut the glass sheet MG, and a separating step in which a fusion-cut portion 6a formed on the glass sheet MG at the fusion-cutting step becomes a filament-like separated material 7a.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for producing a glass sheet. [Background technology]

[0002] Laser cutting is a well-known method for cutting a glass plate. For example, Patent Document 1 discloses a method for cutting a glass substrate of a predetermined shape from a mother glass plate (glass sheet source) by irradiating the glass plate with a laser beam while moving the laser beam along a planned cutting line (cutting line) set on the glass plate.

[0003] In this cutting method, a mother glass plate is supported by a support structure, and a planned cutting line that surrounds the final shape of the glass substrate is defined on the mother glass plate (see paragraph 0019 and Figure 2 of the document). The planned cutting line is configured as a closed loop (closed pattern) that includes straight and curved portions.

[0004] Then, an initial crack (scratch) is formed on the surface of the mother glass plate at the starting position of the planned cutting line by a mechanical marking device (e.g., a marking wheel) (see paragraph 0021 of the same document).

[0005] Next, a laser beam is irradiated onto the area where the initial crack has formed, locally heating the mother glass plate. Furthermore, a cooling fluid is supplied to the mother glass plate to rapidly cool the heated area. This causes tensile stress to act on the mother glass plate, transforming the initial crack into a fissure (see paragraph 0022 of the same document).

[0006] Furthermore, the laser beam irradiated onto the mother glass plate is moved along the planned cutting line, thereby propagating the crack along the planned cutting line, and by moving the laser beam from the start position of the planned cutting line to the end position, a glass substrate having a shape corresponding to the planned cutting line is formed. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2020-180043 Summary of the Invention [Problem to be solved by the invention]

[0008] In a glass plate cutting method using laser cutting, as described above, it is necessary to form an initial crack on the surface of the mother glass plate at the start of cutting. As a result, this initial crack remains on the cut surface of the glass substrate. With the initial crack remaining, the strength of the glass substrate is insufficient, and there is a risk that the glass substrate will break if an impact or the like is applied.

[0009] The present invention has been made in view of the above circumstances, and has as its technical object to cut a glass sheet without forming an initial crack. [Means for solving the problem]

[0010] (1) The method for manufacturing a glass plate of the present invention is intended to solve the above-mentioned problems, and is characterized by comprising a fusing step of fusing the glass plate by irradiating a laser beam along a closed-loop planned cutting line set on the glass plate, and a peeling step of generating fibrous peeling material from the fused portion formed on the glass plate by the fusing step.

[0011] According to this configuration, by fusing the glass sheet with a laser beam in the fusing step, the glass sheet can be cut without forming initial cracks in the glass sheet. Also, by generating fibrous peeled material from the fused portion formed in the glass sheet in the peeling step, the cut surface of the glass sheet can be made to be a high-strength surface without microcracks and requiring no finishing process such as polishing.

[0012] Furthermore, by configuring the planned cutting line as a closed loop, not only the glass portion inside the planned cutting line but also the glass portion outside the planned cutting line can be used as a glass plate product with an opening after cutting.

[0013] (2) In the method for producing a glass plate according to the above (1), in the fusing step, the laser light may be irradiated only along the planned cutting line, thereby allowing the glass portion outside the closed-loop planned cutting line to also be used as a glass plate product after cutting.

[0014] (3) In the method for producing a glass plate according to the above (1) or (2), the planned cutting line may include a straight line and a curved line.

[0015] (4) In the method for manufacturing a glass plate described in any one of (1) to (3) above, in the fusing step, the laser light is moved relative to the glass plate, so that the laser light is irradiated so as to move in a predetermined direction along the planned cutting line; in the fusing step, the laser light is irradiated to a start point set on the planned cutting line, and then the laser light is moved in the predetermined direction, so that the laser light moves around the planned cutting line and reaches the start point; and in the fusing step, the laser light, which has reached the start point after circling the planned cutting line, may be moved beyond the start point.

[0016] According to this configuration, when the laser light makes a full circle around the closed-loop planned cutting line and returns to the starting point, the laser light can be moved beyond this starting point, thereby reliably cutting the glass plate without leaving any uncut portions.

[0017] (5) In the method for producing a glass plate according to any one of (1) to (4), the wavelength of the laser light may be 2.0 μm or more and 11.0 μm or less, thereby enabling the glass plate to be uniformly heated in its thickness direction.

[0018] (6) In the method for producing a glass sheet according to any one of (1) to (5), the laser light may be any one of a CO laser, a CO laser, an Er laser, a Ho laser, and an HF laser, thereby enabling uniform heating of the glass sheet in its thickness direction.

[0019] (7) In the method for producing a glass plate according to any one of (1) to (6) above, in the peeling step, the fusion-cutting portion may be naturally cooled. This allows the glass plate to be cut without supplying a cooling fluid or the like to the glass plate, and prevents the resulting fibrous peeled material from coming into contact with the glass plate and causing scratches on the glass plate.

[0020] (8) In the method for producing a glass plate according to any one of (1) to (7), the width of the peeled material may be 0.1 mm or more and 0.3 mm or less, thereby preventing scratches from being formed on the cut surface due to contact between the glass portion inside the planned cutting line and the glass portion outside the planned cutting line when the glass portion is separated.

[0021] (9) In the method for producing a glass plate according to any one of (1) to (8) above, the glass plate may have a thickness of 0.15 mm or less, thereby enabling the glass plate to be uniformly heated in the thickness direction.

[0022] (10) In the method for manufacturing a glass plate according to any one of (1) to (9) above, in the fusing step, the laser beam is irradiated so as to move in a predetermined direction along the planned cutting line by moving the laser beam relative to the glass plate, and the laser beam may satisfy the relationships 9≦P≦100 and 0.73V-16≦P≦2.6V-4, where P (W) is the output power of the laser beam and V (mm / s) is the moving speed of the laser beam when moving along the planned cutting line. By setting the output power and moving speed of the laser beam within these ranges, it is possible to provide the energy required to fusing the glass plate and to apply thermal strain sufficient to generate peeling material to the fused portion. Furthermore, reducing the output power of the laser beam can also reduce equipment costs.

[0023] (11) In the method for producing a glass plate according to any one of (1) to (10), the thermal expansion coefficient of the glass plate is 30×10 -7 / ℃ or more 100×10 -7 / °C or less. In this way, sufficient thermal strain can be generated when the fusion portion heated by the laser beam is cooled, and peeling can be more reliably generated.

[0024] (12) In the method for manufacturing a glass plate described in any one of (1) to (11) above, in the fusing step, the glass plate is supported by a support member, and the support member may include a base plate and a spacer disposed between the base plate and the glass plate.

[0025] According to this configuration, the glass sheet can be cut without contacting the glass sheet with the surface plate. [Effects of the Invention]

[0026] According to the present invention, it is possible to cut a glass sheet without forming an initial crack. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a side view showing a glass plate manufacturing apparatus and a glass plate manufacturing method. FIG. [Figure 2] 1 is a plan view showing a glass sheet manufacturing apparatus and a glass sheet manufacturing method. FIG. [Figure 3] FIG. 3 is a side view showing a peeling step in the method for manufacturing a glass plate. [Figure 4] FIG. 2 is a plan view showing a fusion cutting step in the method for manufacturing a glass plate. [Figure 5] FIG. 2 is a perspective view of a manufactured glass plate. [Figure 6] FIG. 10 is a side view showing another example of the glass sheet manufacturing apparatus and manufacturing method. [Figure 7] 10 is a graph showing the relationship between the moving speed of a laser beam for cutting a glass plate and the output of the laser beam. [Figure 8] 10 is a graph showing the relationship between the moving speed of a laser beam for cutting a glass plate and the output of the laser beam. DETAILED DESCRIPTION OF THE INVENTION

[0028] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. Figures 1 to 6 show an embodiment of a method for producing a glass plate according to the present invention.

[0029] 1 and 2 show a glass plate manufacturing apparatus used in this method. The manufacturing apparatus 1 manufactures a glass plate to be used as a product by cutting a portion of a mother glass plate MG. As shown in Fig. 1, the manufacturing apparatus 1 includes a support member 2 that supports the mother glass plate MG and a laser irradiation device 3 that irradiates the mother glass plate MG with laser light L.

[0030] As shown in FIGS. 1 and 2, the support member 2 includes a surface plate 4 and spacers 5a to 5e disposed between the surface plate 4 and the mother glass plate MG.

[0031] The surface plate 4 is made of, for example, aluminum or other metals or stone, but the material of the surface plate 4 is not limited to that in this embodiment. The surface plate 4 has a support surface 4a that supports the mother glass plate MG. The surface plate 4 is configured to be movable three-dimensionally in the horizontal and vertical directions by a driving device (not shown).

[0032] The spacers 5a to 5e are made of, for example, glass plates or metal plates, but the material of the spacers 5a to 5e is not limited to this embodiment. The spacers 5a to 5e are rectangular and have the same dimensions, but the shape and dimensions of the spacers 5a to 5e are not limited to this embodiment. The thickness of the spacers 5a to 5e is, for example, 1 mm or more and 10 mm or less. The spacers 5a to 5e include a first spacer 5a, a second spacer 5b, a third spacer 5c, a fourth spacer 5d, and a fifth spacer 5e.

[0033] The laser irradiation device 3 is disposed above the support member 2. The laser irradiation device 3 is fixed in a fixed position, but is not limited thereto and may be configured to be movable three-dimensionally. The laser light L irradiated from the laser irradiation device 3 is preferably any one of a CO2 laser, a CO laser, an Er laser, a Ho laser, and an HF laser.

[0034] The mother glass plate MG and the glass plate produced from the mother glass plate MG are made of, for example, silicate glass, silica glass, borosilicate glass, soda glass, soda lime glass, aluminosilicate glass, alkali-free glass, etc. The glass plate produced from the mother glass plate MG may then be subjected to a chemical strengthening treatment.

[0035] The alkali-free glass is glass that does not substantially contain alkali components (alkali metal oxides), and specifically, glass that has an alkali component weight ratio of 3000 ppm or less. In the present invention, the alkali component weight ratio is preferably 1000 ppm or less, more preferably 500 ppm or less, and most preferably 300 ppm or less.

[0036] The thickness of the mother glass plate MG and the glass plate produced from the mother glass plate MG is preferably 0.03 mm or more and 0.15 mm or less. The lower limit of the thickness of the mother glass plate MG and the glass plate is more preferably 0.05 mm or more. The upper limit of the thickness of the mother glass plate MG and the glass plate is more preferably 0.1 mm or less. The thermal expansion coefficient of the mother glass plate MG and the glass plate is preferably 30×10 -7 / ℃ or more 100×10 -7 The lower limit of the thermal expansion coefficient of the mother glass plate MG and the glass plate is more preferably 35×10 -7 The upper limit of the thermal expansion coefficient of the mother glass plate MG and the glass plate is more preferably 95×10 -7 / ℃ or less.

[0037] Hereinafter, a description will be given of a method for manufacturing a glass plate from a mother glass plate MG using the above-described manufacturing apparatus 1. This method includes a preparation step of placing the mother glass plate MG on a support member 2 and a cutting step of cutting the mother glass plate MG with a laser irradiation device 3.

[0038] In the preparation step, spacers 5a to 5e are placed on the support surface 4a of the surface plate 4. In this embodiment, the first spacer 5a is set as the center, and the second spacers 5b to the fifth spacers 5e are arranged around it. The second spacers 5b to the fifth spacers 5e are arranged at positions spaced apart from the first spacer 5a. The distance D1 between the first spacer 5a and the second spacers 5b to the fifth spacers 5e is, for example, 10 mm or more and 20 mm or less.

[0039] Next, the mother glass plate MG is placed so as to come into contact with each of the spacers 5a to 5e. Although the mother glass plate MG according to this embodiment is rectangular, the shape of the mother glass plate MG is not limited to this embodiment.

[0040] Thereafter, a cutting line CL is virtually set on the mother glass plate MG. The cutting line CL is set in a closed loop shape so as to surround the first spacer 5a. The cutting line CL is set in a rectangular shape that is larger than the first spacer 5a.

[0041] The planned cutting line CL includes a plurality of straight line portions CLa1 to CLa4 and a plurality of curved line portions CLb1 to CLb4, but the shape of the planned cutting line CL is not limited to that in this embodiment. The planned cutting line CL may be composed of only a plurality of straight line portions or only a plurality of curved line portions, or may be composed of only one curved line portion such as a circle or an ellipse.

[0042] The plurality of straight line portions CLa1 to CLa4 on the planned cutting line CL include a first straight line portion CLa1, a second straight line portion CLa2, a third straight line portion CLa3, and a fourth straight line portion CLa4. The plurality of curved line portions CLb1 to CLb4 on the planned cutting line CL include a first curved line portion CLb1, a second curved line portion CLb2, a third curved line portion CLb3, and a fourth curved line portion CLb4.

[0043] The first straight line portion CLa1 and the second straight line portion CLa2 are arranged so as to form a substantially right angle. The first straight line portion CLa1 and the third straight line portion CLa3 are arranged so as to be substantially parallel with a predetermined distance between them. The length of the first straight line portion CLa1 is substantially equal to the length of the third straight line portion CLa3. The second straight line portion CLa2 and the fourth straight line portion CLa4 are arranged so as to be substantially parallel with a predetermined distance between them. The length of the second straight line portion CLa2 is substantially equal to the length of the fourth straight line.

[0044] The first curved portion CLb1 is disposed between the first straight portion CLa1 and the second straight portion CLa2. The first curved portion CLb1 connects one end of the first straight portion CLa1 to one end of the second straight portion CLa2. The first curved portion CLb1 is configured in an arc shape, but is not limited to this shape. The radius of curvature of the first curved portion CLb1 is, for example, 1 mm or more and 20 mm or less. The lower limit of the radius of curvature of the first curved portion CLb1 is more preferably 3 mm or more, and even more preferably 5 mm or more. The second curved portion CLb2 to the fourth curved portion CLb4 have the same shape as the first curved portion CLb1.

[0045] The second curved portion CLb2 connects the second straight portion CLa2 and the third straight portion CLa3. The third curved portion CLb3 connects the third straight portion CLa3 and the fourth straight portion CLa4. The fourth curved portion CLb4 connects the first straight portion CLa1 and the fourth straight portion CLa4.

[0046] 2, in a plan view, the straight line portions CLa1 to CLa4 and the curved line portions CLb1 to CLb4 of the planned cutting line CL are set at positions spaced outward from the four sides of the first spacer 5a. Also, the straight line portions CLa1 to CLa4 and the curved line portions CLb1 to CLb4 of the planned cutting line CL are set at positions spaced inward from the second spacer 5b to the fifth spacer 5e.

[0047] The distance D2 between each of the straight line portions CLa1 to CLa4 of the planned cutting line CL and each side of the first spacer 5a is, for example, not less than 5 mm and not more than 10 mm.

[0048] The cutting process includes a fusing process in which the mother glass plate MG is fusing by irradiating laser light L along the planned cutting line CL, and a peeling process in which fibrous peel material is generated from the fusing portion formed in the mother glass plate MG by the fusing process.

[0049] 2, in the fusing process, after irradiating a start point SP (irradiation start position) set on the planned cutting line CL with laser light L, the laser light L is moved in a predetermined direction (clockwise direction indicated by the arrow in FIG. 2) so that the laser light L goes around the planned cutting line CL and reaches the start point SP. In this embodiment, the start point SP from which irradiation of the laser light L starts is set at a midpoint of the first straight line portion CLa1 of the planned cutting line CL, but is not limited thereto, and the start point SP may be set at a midpoint of the second straight line portion CLa2 to the fourth straight line portion CLa4.

[0050] In the fusing process, the laser light L is moved relative to the mother glass plate MG, and the laser light L is irradiated so as to move in a predetermined direction along the planned cutting line CL. That is, in the fusing process, the laser light L is moved relative to the mother glass plate MG by moving the surface plate 4 in the horizontal direction with respect to the laser irradiation device 3 that is in a fixed position. This is not limitative, and the laser light L may be moved relatively by fixing the surface plate 4 in a fixed position and moving the laser irradiation device 3. Alternatively, the laser light L may be moved relatively by moving the laser irradiation device 3 and the surface plate 4. Alternatively, the mother glass plate MG and the irradiation head of the laser light L may be fixed, and the irradiation position may be moved by changing the angle of a mirror arranged on the light path.

[0051] In the fusing step, it is preferable to irradiate only the lines to cut CL with the laser light L. Therefore, the laser light L is not irradiated onto portions of the mother glass plate MG other than the lines to cut CL.

[0052] When the output power of the laser beam is P (W) and the moving speed of the laser beam along the planned cutting line is V (mm / s), the relationship between the output power P of the laser beam and the moving speed V preferably satisfies the relationships 9≦P≦100 and 0.71V-14≦P≦2.6V-4, and more preferably satisfies the relationships 22≦P≦72 and 0.73V-16≦P≦1.7V-28.

[0053] The lower limit of the wavelength of the laser light L is preferably 2.0 μm or more, more preferably 5.0 μm or more, and the upper limit is preferably 11.0 μm or less, more preferably 6.0 μm or more.

[0054] The peeling step proceeds almost simultaneously with the fusing step. A specific embodiment of the peeling step will be described below with reference to FIG.

[0055] When the mother glass plate MG is irradiated with laser light L (see FIG. 3(a)), a portion of the mother glass plate MG is melted by the heat of the laser light L (see FIG. 3(b)). As shown in FIG. 3(b), the melted portion includes a first melting portion 6a and a second melting portion 6b. The first melting portion 6a is located inside the planned cutting line CL, and the second melting portion 6b is located outside the planned cutting line CL. A distance D3 between the first melting portion 6a and the second melting portion 6b is, for example, 0.03 mm or more and 0.05 mm or less.

[0056] Each of the fusion parts 6a, 6b is naturally cooled as the laser light L moves away from it. Here, natural cooling means that cooling is performed without spraying a cooling fluid such as air onto the part irradiated with the laser light L.

[0057] When the fused portions 6a and 6b are cooled, thermal distortion occurs, and the resulting stress acts as a tensile force on the unfused portions, causing the fused portions 6a and 6b to peel off as fibrous peeled-off materials 7a and 7b (see FIG. 3(c)).

[0058] That is, the first fusing portion 6a becomes a first peeled object 7a and peels off from the mother glass plate MG, and the second fusing portion 6b becomes a second peeled object 7b and peels off from the mother glass plate MG. The width W of each peeled object 7a, 7b is preferably 0.1 mm or more and 0.3 mm or less. The lower limit of the width W is more preferably 0.15 mm or more, and the upper limit is more preferably 0.25 mm or less. When the fusing portions 6a, 6b become peeled objects 7a, 7b and separate from the mother glass plate MG, a first end face Ga and a second end face Gb are newly formed on the mother glass plate MG. The distance D4 between the first end face Ga and the second end face Gb is, for example, 0.3 mm or more and 0.7 mm or less.

[0059] 4 shows the state in which the laser beam L has traveled almost one full circle around the planned cutting line CL and reached a position near the starting point SP. The laser beam L moves along the planned cutting line CL toward the starting point SP to fuse the remaining portion of the mother glass plate MG that has not yet been fused. When the laser beam L reaches the starting point SP (has traveled one full circle around the planned cutting line CL), it does not stop there but moves beyond the starting point SP (see the two-dot chain line) to an ending point EP (irradiation end position), as shown by the dashed-dotted line in FIG. 4. The distance that the laser beam L travels beyond the starting point SP, i.e., the distance D5 between the starting point SP and the ending point EP, is, for example, 10 mm or more and 20 mm or less.

[0060] As described above, by setting the end point EP of the laser beam L at a position beyond the start point SP, the mother glass plate MG can be reliably cut along the entire circumference of the planned cutting line CL. When the laser beam L reaches the end point EP, the laser irradiation device 3 and the surface plate 4 stop, and the cutting process ends.

[0061] When the cutting process is completed, the mother glass plate MG is separated into two glass plates G1 and G2. That is, as shown in Fig. 5, the mother glass plate MG is separated into a first glass plate G1 consisting of the portion inside the planned cutting line CL and a second glass plate G2 consisting of the portion outside the planned cutting line CL.

[0062] The first glass plate G1 is formed in a rectangular shape having straight and curved portions according to the shape of the planned cutting line CL. The end faces of the four sides of the first glass plate G1 are formed as first end faces Ga by the first fusing portion 6a peeling off as first peeled objects 7a in the peeling step.

[0063] The second glass plate G2 has a rectangular opening 8 formed by cutting the first glass plate G1 from the mother glass plate MG. The edge of the opening 8 is constituted by a second end surface Gb formed by the second fusing portion 6b being peeled off as a second peeled object 7b in the peeling step.

[0064] According to the manufacturing method of the glass plates G1, G2 according to the present embodiment described above, in the fusing step, the mother glass plate MG is fused with the laser light L, so that the mother glass plate MG can be cut without forming initial cracks in the mother glass plate MG. Furthermore, in the peeling step, fibrous peeled matter 7a, 7b is generated from the fused portions 6a, 6b, so that the cut surfaces (edge ​​surfaces Ga, Gb) of the glass plates G1, G2 can be made into high-strength surfaces free of microcracks.

[0065] Furthermore, by configuring the planned cutting line CL in a closed loop shape, it becomes possible to use not only the glass portion inside the planned cutting line CL (first glass plate G1), but also the glass portion outside the planned cutting line CL (second glass plate G2) as a glass plate product.

[0066] In the above embodiment, the mother glass plate MG is prevented from contacting the surface plate 4 by interposing the spacers 5a to 5e between the mother glass plate MG and the surface plate 4. When a metal surface plate 4 is used, if the mother glass plate MG is in contact with the support surface 4a of the surface plate 4, there is a risk that the mother glass plate MG will not be sufficiently heated by the laser light L in the fusing process. According to the present embodiment, by separating the mother glass plate MG from the surface plate 4, it is possible to achieve sufficient heating of the mother glass plate MG in the fusing process. Furthermore, by preventing the surface plate 4 from being heated by the laser light L, it is possible to prevent the surface plate 4 from being deformed or discolored due to heating.

[0067] The present invention is not limited to the configuration of the above-described embodiment, nor is it limited to the above-described effects. The present invention can be modified in various ways without departing from the spirit of the present invention.

[0068] 6, a pressing member 9 may be placed on the upper surface of the mother glass plate MG in the preparation step and the cutting step. The pressing member 9 is configured in a plate shape, but the shape of the pressing member 9 is not limited to that of this embodiment. For example, a rectangular glass plate is used as the pressing member 9, but the material of the pressing member 9 is not limited to that of this embodiment.

[0069] The pressing member 9 is placed on the upper surface of the mother glass plate MG so as to overlap the spacers 5a to 5e. By sandwiching the mother glass plate MG between the pressing member 9 and the spacers 5a to 5e, deformation and displacement of the mother glass plate MG are prevented, and the mother glass plate MG can be cut stably.

[0070] In the above embodiment, the spacers 5a to 5e are interposed between the mother glass plate MG and the surface plate 4 to prevent the mother glass plate MG from contacting the surface plate 4, but this is not limiting. Grooves may be provided on the surface plate 4 at positions corresponding to the planned cutting lines CL to prevent the mother glass plate MG from contacting the surface plate 4 on the planned cutting lines CL. [Example]

[0071] Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0072] The inventors conducted a glass plate cutting test to confirm the effects of the present invention. In this test, two types of glass plates (first glass plate and second glass plate) with different compositions were cut using the method of the above embodiment. The thickness of the glass plate (mother glass plate) used for cutting was 0.05 mm.

[0073] The first glass plate used for cutting is made of alkali-free glass. The thermal expansion coefficient of the first glass plate is 38×10 -7 / °C. The second glass plate used for cutting is made of alkali aluminosilicate glass. The thermal expansion coefficient of the second glass plate is 91×10 -7 / ℃.

[0074] In this test, a plurality of first glass plates and a plurality of second glass plates were prepared, and the laser beam irradiation conditions (laser beam output, laser beam movement speed) were changed, and the laser beam was irradiated along a closed-loop planned cutting line set on each glass plate. The diameter of the laser beam at the focus point was 30 μm. The portion cut out of the glass plate along the planned cutting line was rectangular, measuring 50 mm × 90 mm. The corners of the portion cut out of the glass plate were configured as arcs with a curvature radius of 10 mm.

[0075] This test confirmed the irradiation conditions of the laser beam capable of cutting the glass plate. The test results are shown in Figures 7 and 8. Figure 7 shows the cutting results of the first glass plate. Figure 8 shows the cutting results of the second glass plate. In Figures 7 and 8, data in which the glass plate was able to be cut by the laser beam, fibrous peeling material was generated from the cut portion, and the quality of the cut surface was good is indicated by "◯". In addition, data in which the glass plate was able to be cut by the laser beam, fibrous peeling material was generated from the cut portion, but unevenness was observed on the cut surface is indicated by "△". Furthermore, data in which the glass plate could not be cut by the laser beam, or in which the glass plate could be cut by the laser beam, but fibrous peeling material was not generated from the cut portion is indicated by "X".

[0076] 7 and 8 are lines that represent P=2.6V-4 and P=0.73V-16, respectively, where P (W) is the output power of the laser beam and V (mm / s) is the moving speed of the laser beam along the planned cutting line. Furthermore, lines L2 and L4 in FIGS. 7 and 8 are lines that represent the upper limit P=100 and the lower limit P=9 of the output power P of the laser beam. In the range enclosed by lines L1, L2, L3, and L4, the glass plate can be fused and peeled material can be generated from the fused portion.

[0077] When the laser beam output P is greater than line L1, the unmelted portion is heated, and sufficient tensile force cannot be applied to the fused portion, resulting in no peeling. By setting the laser beam output P equal to or less than line L1, sufficient tensile force can be applied to the fused portion, resulting in no peeling. When the laser beam output P is greater than line L2, a laser irradiation device capable of achieving such an output is expensive, resulting in high equipment costs. Setting the laser beam output P equal to or less than line L2 reduces equipment costs. When the laser beam output P is less than line L3, the glass sheet is not heated sufficiently, resulting in no melting of the glass sheet. By setting the laser beam output P equal to or greater than line L3, the glass sheet can be heated sufficiently and melted. When the laser beam output P is less than line L4, it takes a long time to heat the glass sheet, and sufficient tensile force cannot be applied to the fused portion, resulting in no peeling. By setting the laser beam output P equal to or greater than line L4, sufficient tensile force can be applied to the fused portion, resulting in no peeling.

[0078] 7 and 8 are lines where P=1.7V-28 and P=0.71V-14, respectively. Also, lines L6 and L8 are lines where P=80 and P=22, respectively, are the upper and lower limits of the laser beam output P. In the range enclosed by lines L5, L6, L7, and L8, the glass plate can be fused and cut, and peeling material can be generated from the fused portion, resulting in a better cut surface.

[0079] When the laser beam output P is greater than line L5, the unmelted portion is heated, and sufficient tensile force cannot be applied to the fused portion, resulting in no peeling. By setting the laser beam output P equal to or less than line L5, sufficient tensile force can be applied to the fused portion, resulting in more reliable peeling. When the laser beam output P is greater than line L6, a laser irradiation device capable of achieving such an output is expensive, increasing equipment costs. By setting the laser beam output P equal to or less than line L6, equipment costs can be further reduced. When the laser beam output P is less than line L7, the glass sheet cannot be sufficiently heated, resulting in no melting of the glass sheet. By setting the laser beam output P equal to or greater than line L7, the glass sheet can be sufficiently heated, resulting in more reliable melting of the glass sheet. When the laser beam output P is less than line L8, it takes a long time to heat the glass sheet, and the unmelted portion is heated, resulting in insufficient tensile force to be applied to the fused portion, resulting in no peeling. By setting the output P of the laser light to be equal to or greater than the line L8, a sufficient tensile force is applied to the fused portion, and the peeled material can be more reliably generated. [Explanation of symbols]

[0080] 2 Support member 3 Laser irradiation device 4 Surface Plate 5a First spacer 5b Second spacer 5c Third spacer 5d Fourth spacer 5e Fifth Spacer 6a First fusing part 6b Second fusing part 7a First peeled object 7b Second peeled material CL cutting line CLa1 First straight section CLa2 Second straight section CLa3 3rd straight section CLa4 Fourth straight line CLb1 First curve part CLb2 Second curve part CLb3 Third curve part CLb4 Fourth curve part L laser light MG mother glass plate SP starting point W Width of peeled material

Claims

1. a fusing step of fusing the glass sheet by irradiating the glass sheet with laser light along a closed-loop planned cutting line set on the glass sheet; a peeling step of generating fibrous peeled material from the fusion-cut portion formed in the glass plate by the fusion-cutting step.

2. The method for manufacturing a glass plate according to claim 1 , wherein in the fusing step, the laser light is irradiated only onto the intended cutting line.

3. The method for manufacturing a glass plate according to claim 1 or 2, wherein the planned cutting line includes a straight line and a curved line.

4. In the fusing step, the laser light is irradiated so as to move in a predetermined direction along the planned cutting line by moving the laser light relative to the glass plate, In the fusing step, the laser light is irradiated onto a start point set on the planned cutting line, and then the laser light is moved in the predetermined direction, so that the laser light travels around the planned cutting line and reaches the start point, 3. The method for manufacturing a glass plate according to claim 1, wherein in the fusing step, the laser light that has traveled around the planned cutting line and reached the starting point is moved beyond the starting point.

5. 3. The method for manufacturing a glass plate according to claim 1, wherein the wavelength of the laser light is 2.0 μm or more and 11.0 μm or less.

6. The laser light is CO ２ 3. The method for producing a glass plate according to claim 1, wherein the laser beam is any one of a laser beam from a laser, a CO laser, an Er laser, a Ho laser, and a HF laser.

7. 3. The method for manufacturing a glass plate according to claim 1, wherein the fusion portion is naturally cooled in the peeling step.

8. 3. The method for manufacturing a glass plate according to claim 1, wherein the width of the peeled material is 0.1 mm or more and 0.3 mm or less.

9. 3. The method for manufacturing a glass plate according to claim 1, wherein the glass plate has a thickness of 0.15 mm or less.

10. In the fusing step, the laser light is irradiated so as to move in a predetermined direction along the planned cutting line by moving the laser light relative to the glass plate, When the output of the laser light is P (W) and the moving speed of the laser light when moving along the planned cutting line is V (mm / s), 9≦P≦100 and 0.73V-16≦P≦2.6V-4 3. The method for producing a glass plate according to claim 1, wherein the following relationship is satisfied:

11. The thermal expansion coefficient of the glass plate is 30×10 -7 / ℃ or more 100 x 10 －7 3. The method for producing a glass plate according to claim 1, wherein the temperature is 1000° C. or less.

12. In the fusing step, the glass plate is supported by a support member, 3. The method for manufacturing a glass plate according to claim 1, wherein the support member comprises a surface plate and a spacer disposed between the surface plate and the glass plate.

Images