TW201619081A - Method of chamfering glass - Google Patents

Abstract

Disclosed is a method of chamfering a glass substrate, which is performed by contacting a heating member to an edge of a glass substrate, wherein a heat quantity supplied to the glass substrate is 10 to 200 Kcal, and a pressure applied to the glass substrate by the heating member is 300 to 700 kgf/cm2. Thereby, it is possible to reduce surface roughness of a glass substrate due to being uniformly distributed stress, and improve elongation of the glass substrate.

Description

Method of chamfering glass

The present invention relates to a method of chamfering a glass by chamfering a glass substrate by applying heat and pressure within a predetermined range to the glass substrate.

Glass products are used in a wide range of technologies and industries such as video and optical equipment (such as monitors, cameras, VTRs, mobile phones or the like), transportation equipment (such as automobiles), various tableware, construction facilities, or the like. Processed as an integrated component. Therefore, glass having various properties is manufactured and currently used according to the characteristics of each industry field.

Among them, the display is very important as a key component of video equipment to attract public attention.

Typically, such a glass substrate for a display can be produced by a floating method and an overflow method. The floating method refers to a method in which molten glass flowing from a melting furnace is cooled by dropping the molten glass downward to prepare a glass substrate; and the overflow method refers to a method in which a molten glass boiling in a melting furnace flows horizontally to prepare a glass substrate . The floating method additionally requires a grinding process, but can produce a wider product than the overflow method. Due to this advantage, the floating method is widely used in the manufacture of glass substrates.

When a floating method is used, the desired glass substrate can be produced by performing a melting, quenching, cutting, chamfering, and grinding process and then washing and drying the above glass substrate.

In such processes, when a glass substrate is manufactured using a conventional chamfering process, particles generated during the process can be a major factor causing contamination of the surface of the thin glass sheet, so that the final step in the manufacturing process of the glass substrate. A large number of washing and drying processes are required, and thereby an increase in manufacturing costs due to additional steps can occur. In addition, the surface of the thin glass sheet can be severely damaged by particles and debris trapped between the belt and the thin glass sheet, which causes interruption of a series of processing steps, and a reduction in the number of product selections, and thereby causes processing The rate is reduced.

In order to solve the problems described above, Korean Patent Laid-Open Publication No. 2013-0081541 discloses a method of cutting a strip-shaped glass edge using MoSi2 as a heat source to minimize the particles generated during the treatment of the edges of the glass substrate. Herein, since the above method is a method of chamfering a glass substrate by using heat, the case of the glass surface is important. However, the above method has a problem that a non-uniform heat distribution attributed to the chips before the treatment exists in the glass substrate, and the glass surface is nonlinear, thereby causing a stress concentration phenomenon which causes a decrease in the strength of the glass.

An object of the present invention is to provide a method of chamfering a glass substrate capable of reducing the surface roughness of a glass substrate.

Another object of the present invention is to provide a method of chamfering a glass substrate capable of improving the elongation of the glass substrate.

The above objects of the present invention will be achieved by the following features:

(1) A method of chamfering a glass substrate by contacting a heating member with an edge of a glass substrate, wherein heat supplied to the glass substrate is 10 to 200 kcal, and The pressure applied to the glass substrate by the heating member is 300 to 700 kgf/cm 2 .

(2) The method according to (1) above, wherein the edge of the glass substrate is cut by thermal stress.

(3) The method according to (1) above, wherein the glass substrate has a heat transfer coefficient of 0.5 to 1 Kcal/mh °C.

(4) The method according to (1) above, wherein the heating member has a temperature of 1,200 to 1,700 ° C during chamfering.

(5) The method according to (1) above, wherein the heating member moves at a moving speed of 0.5 to 5 m/min during chamfering.

(6) The method according to (1) above, wherein the chamfered surface of the glass substrate has a surface roughness of 20 μm or less.

(7) The method according to (1) above, wherein the glass substrate is a tempered glass substrate.

(8) The method according to (7) above, wherein the tempered glass substrate has a Vickers hardness of 600 to 700 kgf/mm 2 .

(9) The method according to (7) above, wherein the strengthened glass substrate has a strengthened layer having a depth of 10 to 200 μm.

According to the present invention, chamfering is performed by applying heat and pressure within a predetermined range to the glass substrate, so that the edges of the glass substrate can be smoothly processed to reduce surface roughness.

Further, when the glass substrate is chamfered by the method of the present invention, stress can be uniformly distributed on the glass substrate to improve its elongation.

Additionally, the glass substrate subjected to the method of the present invention can have improved quality of the glass substrate.

1‧‧‧Upper edge part/predetermined part

2‧‧‧lower edge part/predetermined part

3‧‧‧ required parts

The above and other objects, features and other advantages of the present invention will become more apparent from the aspects of the description of the appended < A view of the cutting plane of the glass substrate when chamfering.

2 is a view schematically illustrating a cutting plane of a glass substrate when the glass substrate is chamfered by the method of Comparative Example 1.

Figure 3 is a schematic cross-sectional view (a) and a front view (b) of a cutting plane chamfered in accordance with the present invention.

4 is a view schematically illustrating a chamfering method according to a specific example of the present invention.

Fig. 5 is a view schematically illustrating a chamfering method according to another embodiment of the present invention.

The present invention discloses a method of chamfering a glass substrate by contacting a heating member with an edge of a glass substrate, wherein heat supplied to the glass substrate is 10 to 200 kcal, and is applied to the glass substrate by a heating member The pressure is 300 to 700 kgf/cm 2 .

Exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

According to the invention, the edges of the glass substrate are chamfered by contacting the heating member with its edges. In this case, the heat Q supplied from the heating member to the glass substrate may depend on the thermal conductivity of the glass, the temperature of the heating source, the temperature of the glass, the moving speed of the heating source, and the heating source moving toward the glass after the heating source contacts the glass. The distance is controlled and is 10 to 200 kcal.

If the supplied heat is less than 10 kcal, the glass substrate is poured by the heating member The angle is not possible due to insufficient thermal stress, and if the heat exceeds 200 kcal, the glass is thermally deformed and can be broken due to excessive thermal stress.

Further, according to the method of chamfering the glass of the present invention, the glass substrate is chamfered while applying a pressure within a predetermined range to the glass substrate by the heating member.

When the glass substrate is chamfered only by bringing the heating member into contact with the glass substrate without adding other process conditions, there is a possibility of preventing particles from occurring during the treatment (which makes the conventional chamfering process of the glass substrate difficult) advantage. However, the debris present at the edge of the glass substrate before chamfering contacts the high temperature heating member to cause uneven heat distribution on the glass substrate, and thereby the stress concentration phenomenon occurs and the strength of the glass is lowered.

In order to solve the problems described above, the present invention provides a method of chamfering a glass substrate by bringing a heating member into contact with a glass substrate while applying pressure within a predetermined range, so that a portion of the glass substrate can be used The high temperature and high pressure heat melt, and thereby the debris present at the edges can be partially removed to apply thermal stress in a relatively uniform depth. Therefore, the chamfered plane is smooth and has a reduced surface roughness Ra. In this case, as long as the surface roughness satisfies the object of the present invention, and can be, for example, 20 μm or less without particularly limiting the lower limit thereof, there is no problem associated with surface roughness.

According to the reduction in surface roughness, the stress can be uniformly distributed in the glass substrate to improve the elongation (strength) of the glass substrate. In this case, as long as the elongation satisfies the object of the present invention and can be, for example, 0.15% or more without particularly limiting the upper limit, there is no problem associated with elongation.

The pressure applied to the glass substrate may be 300 to 700 kgf/cm 2 , and preferably 450 to 650 kgf/cm 2 . If the pressure is less than 300 kgf/cm 2 , Then, the improvement of the elongation is lowered to reduce the effect of improving the strength of the glass substrate, and if the pressure exceeds 700 kgf/cm 2 , fine cracks can be generated in the glass substrate.

In the method of chamfering a glass of the present invention, the heating member contacts the edge of the glass substrate, and thereby the edge portion of the glass substrate is cut attributable to thermal stress to chamfer the glass substrate. When the heating member of the present invention is brought into contact with the edge of the glass substrate, thermal stress is generated at the edge portion in contact with the heating member by the glass characteristic having a low heat transfer rate, and thereby from the portion in contact with the heating source to the predetermined The part of the depth is cut off. Therefore, when the heating member moves while being in contact with the edge of the glass substrate, the edge of the glass substrate can be chamfered.

The glass substrate chamfered according to the method of the present invention for chamfering glass may have a heat transfer coefficient of 0.5 to 1 Kcal/mh ° C (and preferably 0.7 to 0.9 Kcal/mh ° C). When the glass substrate has a heat transfer coefficient within this range, the chamfer according to the present invention can be performed while changing the desired effects of the present invention.

When the glass substrate is chamfered according to the present invention, the heating member may have a temperature of 1,200 to 1,700 ° C during chamfering. In this temperature range, chamfering can be preferably performed, and the chamfering speed can be increased as the temperature is increased within the above range.

When the glass substrate is chamfered according to the present invention, the heating member can be moved at a moving speed of 0.5 to 5 m/min. Within this range, the occurrence of cracking due to thermal shock can be prevented.

The type of chamfered glass substrate according to the chamfering method of the present invention is not particularly limited, and may include, for example, conventional glass, tempered glass or the like. The heating member for chamfering the glass of the present invention can also be applied to tempered glass.

Further, when the object to be chamfered by the present invention is a tempered glass substrate, the hardness of the tempered glass is not particularly limited, but specifically, the tempered glass may have a force of 600 to 700 kg/flat. Vickers hardness of square millimeters. Further, the reinforcing layer of the tempered glass substrate is not particularly limited, but specifically, the reinforcing layer may have a depth of 10 mm to 200 μm. When the glass substrate is chamfered within the above range according to the chamfering method of the present invention, the surface roughness of the glass substrate can be lowered to significantly improve the elongation.

Hereinafter, a chamfering method according to a specific example of the present invention will be described in detail with reference to the accompanying drawings. In the chamfering method according to the present invention, the upper edge portion and the lower edge portion of the side surface of the glass may be chamfered obliquely. Figure 3 is a schematic illustration of the side of a glass chamfered according to the chamfering method of the present invention, wherein (a) is a cross-sectional view and (b) is a front view.

In the method of chamfering the edge portion and the lower edge portion of the side surface of the glass as illustrated in FIG. 3, the specific order or number of contact heat sources, or the inclination angle of the heat source is not particularly limited as long as it is The final shape of the edge portion and the lower edge portion may be formed obliquely.

More specifically, for example, in one embodiment of the present invention, chamfering can be performed by bringing a heat source into contact with an upper edge portion and a lower edge portion of the glass. As schematically illustrated in Fig. 4, the inclined plane can be formed by contacting the heat source with the upper side edge portion 1 and the lower edge portion 2 of the side of the glass.

In another embodiment of the present invention, the chamfering may be performed by contacting the heat source with the upper edge portion and the lower edge portion of the side of the glass, and then heating the source and the side of the glass in a direction parallel to the side of the glass. Execution by contact. This specific example can be effectively used when the area of the tempered glass to be removed by the chamfering method is large. Figure 5 schematically illustrates a chamfering method in accordance with this embodiment. Referring to Fig. 5, the heat source first contacts the upper edge portion of the side of the glass to form an inclined plane 1 to a predetermined portion. Next, the heat source contacts the lower edge portion of the side of the glass to An inclined plane 2 is formed to a predetermined portion. Next, the heat source contacts the side of the glass in a direction parallel to the side of the glass to remove the glass to the desired portion 3, whereby the final cross-sectional shape can be obtained.

Further, in the specific example presented in the present invention, the order of the chamfers may be changed, that is, the chamfering may be performed by an order different from the order illustrated in FIG. For example, the chamfering may be performed in the order of 2, 1, and 3 or in the order of 3, 2, and 1, but is not limited thereto.

When the inclined plane treatment of the side of the glass by the heat source is completed as described above, the reinforcing process of the surface of the side surface of the glass may be further performed as needed. By the enhanced process described above, a more uniform surface of the side of the glass with improved strength can be provided.

Strengthening the process may include grinding the sides of the glass by a grinding wheel or etching the sides of the glass by an etchant composition comprising fluoric acid (HF).

First, a method of grinding the side of the glass by the grinding wheel is performed in such a manner that the side of the rotating grinding wheel contacts the side of the glass to more uniformly grind the side of the glass after the inclined plane is formed by the heating source. Thereby, fine cracks or the like existing on the surface of the side surface of the glass are ground to reinforce the side surface of the glass.

The grinding wheel can use a wheel made of abrasive particles such as cerium oxide. Preferably, the abrasive particles have a size of 5 microns or less depending on the full expression enhancing effect of the sides of the glass. Since the reduction in the size of the abrasive particles leads to an increase in the accuracy of the grinding and grinding, the smaller the better. Therefore, although the lower limit of the size is not particularly limited, abrasive grains having a size of about 0.01 μm may be used in consideration of the process time or the like.

The rotation speed of the grinding wheel is not particularly limited, but it may be appropriately selected to sufficiently grind the side of the glass in order to obtain a desired strength level, and the rotation speed (for example) may be It is 1,000 to 10,000 rpm.

Next, a method of etching the side of the glass using an etchant including a fluoric acid is performed in such a manner that an etchant including a fluoric acid is applied to the side of the glass to etch the surface portion of the side of the glass. When the side of the glass is etched by an etchant composition including hydrofluoric acid, an imprint pattern is formed on the surface of the side surface of the glass by etching to reinforce the surface of the side surface of the glass.

The etchant comprising hydrofluoric acid is a hydrofluoric acid solution, and may further comprise, for example, a desired acid component other than hydrofluoric acid, such as hydrochloric acid, nitric acid or sulfuric acid, etc., which is known in the art as a glass etching composition.

The time for etching the side of the glass by an etchant including hydrofluoric acid is not particularly limited, but may be, for example, in the range of 30 seconds to 10 minutes in the case of increasing the strength of the glass without over-etching on the side of the glass. Etching is performed inside.

The temperature of the etchant including the hydrofluoric acid during the etching is not particularly limited, but the etching is preferably performed, for example, in the range of 20 to 50 °C. If the etching temperature is less than 20 ° C, the process time can be increased and insufficient etching can occur, and the etching temperature exceeds 50 ° C, and the process time is lowered, but the etching can be performed unevenly.

The etchant comprising fluoric acid can be applied to the sides of the glass by any method known in the art, such as by injecting an etchant to the side of the glass, immersing the side of the glass in an etchant, or the like.

In the following, preferred embodiments are proposed to more specifically describe the invention. However, the following examples are given to illustrate the invention, and it is obvious to those skilled in the art that various changes and modifications are possible within the scope and spirit of the invention. Such changes and modifications are properly included in the scope of the appended claims.

Examples and comparative examples

Chamfering is performed by contacting the heat source with the glass substrate under process conditions as described in Table 1 below. During the execution of the process, the ambient temperature was 23.5 ° C and the relative humidity (RH) was 17%.

Corning's Gorilla Glass is used as a glass substrate and its properties are as shown in Table 2 below.

Experimental example

1. Measurement of surface roughness

After chamfering according to the examples and comparative examples, the surface roughness was measured to confirm the degree of wear. When the surface roughness was equivalently measured, a 3D microscope photograph was used, and the measurement results are shown in Table 3 below.

2. Measurement of elongation

The elongation is measured in such a manner that two separate support spans are placed at the opposite sides from the center below the strengthened glass substrate, and when the load is applied to the upper portion of the window substrate by the upper span located on the upper portion of the center of the substrate In part, the distance between the point at which the upper span contact window substrate and the point at which the window substrate is broken (crosshead shift) is measured to calculate the elongation according to the following Equation 1, and the results are shown in Table 3 below. .

[Equation 1] Elongation (%) = (6Tδ) / s ²

(Where T represents the thickness (mm) of the window substrate, δ represents the crosshead displacement (mm), and s represents the distance (mm) between the support spans).

Referring to Table 3 above, it can be seen that the glass substrate chamfered according to the embodiment generally has a lower surface roughness than the glass substrate chamfered by the method of Comparative Example 1.

Further, it can be seen that the glass substrate which is chamfered according to the embodiment has a higher elongation than the glass substrate which is chamfered according to the comparative embodiment.

Claims (9)

A method of chamfering a glass substrate by contacting a heating member with an edge of a glass substrate, wherein a heat supplied to the glass substrate is 10 to 200 kcal, and the heating is performed by the heating The pressure applied to the glass substrate by the member is 300 to 700 kgf/cm 2 . The method of claim 1, wherein the edge of the glass substrate is severed by a thermal stress. The method of claim 1, wherein the glass substrate has a heat transfer coefficient of 0.5 to 1 Kcal/mh °C. The method of claim 1, wherein the heating member has a temperature of 1,200 to 1,700 ° C during chamfering. The method of claim 1, wherein the heating member moves at a moving speed of 0.5 to 5 m/min during chamfering. The method of claim 1, wherein one of the glass substrates has a surface roughness of 20 μm or less via the chamfered surface. The method of claim 1, wherein the glass substrate is a tempered glass substrate. The method of claim 7, wherein the strengthened glass substrate has a Vickers hardness of 600 to 700 kgf/mm 2 . The method of claim 7, wherein the strengthened glass substrate has a strengthened layer having a depth of one of 10 to 200 microns.