TW201609586A - A window substrate and method of chamfering the same - Google Patents

Abstract

Disclosed is a window substrate, including: an embossed pattern on a chamfered portion thereof, wherein the number of embosses having a bottom with a long axis length of 5 mm or more is 60% or more to a total number of embosses, thereby capable of suppressing breakage due to significantly improving elongation.

Description

Window substrate and its chamfering method

The present invention relates to a window substrate having excellent elongation and a method of chamfering a cutting plane of a window substrate.

Generally, the cutting and chamfering process of a window substrate for a flat panel display is performed as follows.

First, there is a mechanical cutting method comprising: mechanically engraving an inspection line on a glass plate by letting a diamond or carbide engraving wheel pass over the surface of the glass plate; and then bending the glass by examining the engraved line The plate is cut to form its cutting edge. Generally, in the above mechanical cutting method, it is possible to form a transverse crack having a depth of about 100 to 150 mm in the glass sheet, wherein the crack is generated from the cutting line of the engraving wheel. Since the lateral cracks reduce the strength of the window substrate, the cut portion of the window substrate should be removed by polishing.

Next, there is a non-contact cutting method using a laser beam, comprising: expanding a glass surface by moving a laser beam along a predetermined path on the surface of the glass and passing through an inspection line engraved on the edge of the window substrate; Immediately following the laser beam, the glass surface is extended with a cooler; and heat propagates cracks along the forward path of the laser beam to cut the window substrate.

Since the cutting plane of the window substrate cut by the above mechanical cutting method or laser beam has a sharp and uneven surface which is easily damaged by external impact, the chamfering process should be performed thereon. The chamfering procedure is generally carried out in two steps, namely by finely grinding the rotating polishing wheel in contact with the cutting plane to polish the cut portion (ie, to chamfer the cut portion), and to erode the polishing by using an etchant. The plane is cut and machined to avoid phenomena such as breakage of corners due to fine cracks present in the chamfered portion.

When the chamfering process is performed, the smoothness of the cut portion can be improved, thereby increasing the strength to a certain extent. However, it is difficult to provide a window substrate having excellent elongation using a conventional chamfering program.

At the same time, Korean Patent Registration No. 0895830 discloses a method of cutting the edge of a glass substrate of a flat display using a cup-shaped grinding wheel, which also suffers from a problem of deteriorated elongation.

Accordingly, it is an object of the present invention to provide a window substrate having excellent elongation.

Another object of the present invention is to provide a method of dehorning a window substrate which can provide a window substrate having excellent elongation.

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

(1) A window substrate comprising: an embossed pattern on a chamfered portion thereof, wherein the number of embossments having a long axis length of 5 mm or longer at the bottom is 60% or more with respect to the total number of embossments many.

(2) The window substrate according to (1) above, wherein the chamfered portion comprises an embossing pattern, wherein the bottom portion has a bottom and the bottom has a long axis length of less than 5 mm with respect to the total number of embossments The number of flowers is 2 to 40%, the number of embossments having a bottom and having a long axis length of 5 mm to 10 mm at the bottom is 20 to 70%, having a bottom and the bottom having more than 10 mm but not exceeding 20 The number of embossments of the long axis length of mm is 10 to 40%, and the number of embossings having a bottom portion and the bottom portion having a long axis length exceeding 20 mm is 0 to 20%.

(3) The window substrate according to (1) above, wherein the window substrate is selected from the group consisting of glass, polyether enamel (PES), polyacrylate (PAR), polyether phthalimide (PEI), Polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polysulfide (PPS), polyarylate, polyamine, polycarbonate (PC), cellulose triacetate At least one of a group consisting of ester (TAC) and cellulose acetate propionate (CAP) is formed.

(4) The window substrate according to (3) above, wherein the glass is tempered glass.

(5) A method of chamfering a window substrate, comprising: polishing the cut portion by bringing the rotary buffing wheel into contact with a cut portion of the window substrate, and moving at a speed of 100 to 800 mm/sec along the cut portion The polishing wheel; and the dicing portion polished by the erosive agent, the etchant comprising a fluorine-containing compound in an amount of 4 to 12 wt.% with respect to the total weight of the etchant, as in the first item of the patent application The embossed pattern is formed on the chamfered portion of the window substrate according to any one of the items 4.

(6) The method according to (5) above, wherein the polishing wheel has a polishing plane on which a cutting medium having a particle size of 200 to 1200 mesh is dispersed.

(7) The method according to (5) above, wherein in the polishing step, the polishing wheel is rotated at a speed of 10,000 to 50,000 rpm.

(8) The method according to (5) above, wherein the temperature of the etchant is 15 to 40 °C.

The window substrate according to the present invention includes a specific embossing pattern on the chamfered portion, whereby damage can be suppressed due to a significant improvement in elongation.

The present invention discloses a window substrate comprising: an embossed pattern on a chamfered portion thereof, wherein the number of embossments having a long axis length of 5 mm or more at the bottom relative to the total number of embossments is 60 % or more, thereby being able to suppress breakage due to a significant improvement in elongation.

Hereinafter, exemplary embodiments of the present invention will be described in detail.

As a typical example of a window substrate cutting method, there are mechanical and optical cutting methods. Since the cutting plane of the window substrate has a sharp and uneven surface (it is susceptible to damage from external impact), the chamfering procedure should be performed thereon.

As described above, such a chamfering process is generally performed in two steps, that is, polishing the cut portion by grinding the rotating polishing wheel in contact with the cutting plane (that is, chamfering the cut portion), and by using The etchant erodes the polished cutting plane to machine the polished cutting plane to avoid phenomena such as corner breakage due to fine cracks present in the chamfered portion.

Figure 1 depicts a chamfered portion of a window substrate in accordance with an embodiment of the present invention (Example 1). The inventors of the present invention conceived that the effect of the embossing of the bottom having a long axis length of 5 mm or more of 60% can significantly improve the elongation with respect to the total number of embossings, and the present invention has been completed in accordance with the idea.

The bottom of the chamfered portion refers to the surface of the ellipse (including the overall ellipse, and the slanted or twisted ellipse) surrounded by the visible edges when viewed from the front of a unit embossing. In addition, the long axis of the bottom refers to the longest line segment connecting the two points on the ellipse.

The window substrate according to the present invention comprises an embossed pattern on the chamfered portion, wherein the number of embossments having a long axis length of 5 mm or more at the bottom with respect to the total number of embossments is 60% or more, and is improved The elongation is preferably from 65 to 95%.

In particular, the window substrate according to the present invention may comprise an embossing pattern on the chamfered portion, wherein the number of embossments having a major axis length of less than 5 mm at the bottom relative to the total number of embossments is 2 to 40%, The number of embossings having a long axis length of 5 mm to 10 mm at the bottom is 20 to 70%, and the number of embossing having a long axis length of more than 10 mm but not exceeding 20 mm at the bottom is 10 to 40%, and the bottom has The number of embossments having a long axis length of more than 20 mm is 0 to 20%. When the embossed pattern contained in the chamfered portion has an embossing within a specific size and ratio range as described above, the effect of improving the elongation can be maximized.

Moreover, the present invention provides a method of chamfering a window substrate to form an embossed pattern on the chamfered portion.

Hereinafter, a specific embodiment of a method of dehorning the window substrate of the present invention will be described in detail.

First, the cut portion of the window substrate is polished.

This polishing step is performed by polishing the sharp cut portion of the window substrate to smooth the surface thereof.

This polishing method uses a method of polishing a cut portion by bringing the rotary buffing wheel into contact with the cutting plane.

Typically, the polishing plane of the polishing wheel that is in contact with the cut portion of the window substrate can include diamond particles, grinding wheels, carbide particles as a cutting medium dispersed in a suitable substrate (i.e., a binder, such as a resin or metal bonding matrix).

The particle size of the cutting medium is not particularly limited, but may be, for example, 200 to 1200 mesh. Within this range, the particle size may be 200 to 1200 mesh, 200 to 1000 mesh, 200 to 800 mesh, 200 to 600 mesh, 250 to 1000 mesh, 400 to 1200 mesh, 400 to 1000 mesh. The number, 400 to 800 mesh, etc., is preferably 250 to 1000 mesh, and more preferably 400 to 800 mesh. When the particle size of the cutting medium falls within the range of 200 to 1200 mesh, polishing can be easily performed, and other program conditions of the polishing step and subsequent etching process conditions can be satisfied at the same time. Thereby, an embossed pattern having embossing within the above specific size and ratio can be formed on the chamfered portion, and strength and elongation can be improved.

The polishing wheel can be moved along the cutting portion while contacting the cutting portion.

The speed of the polishing wheel moving along the cut portion of the window substrate is 100 to 800 mm/sec. Within this range, the speed may be, for example, 100 to 800 mm/sec, 100 to 600 mm/sec, 100 to 400 mm/sec, 150 to 700 mm/sec, 150 to 500 mm/sec, and 200 to 800 mm. /sec, 200 to 600 mm/sec, 200 to 400 mm/sec, 400 to 800 mm/sec, 400 to 600 mm/sec, etc., preferably 150 to 700 mm/sec, and more preferably 200 to 600 mm/sec. When the moving speed of the polishing wheel falls within the range of 100 to 800 mm/sec, other program conditions of the polishing step and subsequent etching process conditions can be simultaneously satisfied, and thus, the specific size and the above-described size can be formed on the chamfered portion. The embossed embossing pattern within the ratio and improves strength and elongation.

When the polishing wheel is circular, it is polished by rotating the wheel. The rotational speed of the polishing wheel is not particularly limited and may be appropriately selected to form an embossed pattern through a subsequent etching step according to the present invention. For example, the rotational speed may be 10,000 to 50,000 rpm, and may be 10,000 to 50,000 rpm, 10,000 to 45,000 rpm, 10,000 to 40,000 rpm, 10,000 to 30,000 rpm, 12,000 to 45,000 rpm, 12,000 to 35,000 rpm, 15,000 in this range. Up to 40,000 rpm, 15,000 to 35,000 rpm, and the like, preferably 12,000 to 45,000 rpm, and more preferably 15,000 to 40,000 rpm. When the rotational speed of the polishing wheel is within this range, other program conditions of the polishing step and subsequent etching process conditions can be satisfied at the same time, and thus, embossing having embossing within the specific size and ratio described above can be formed on the chamfered portion Pattern and improve strength and elongation.

Second, the window substrate subjected to the above polishing step is eroded.

The etching step can improve the smoothness of the chamfered portion to avoid occurrence of a phenomenon such as breakage of a corner due to a fine crack existing in the chamfered portion.

The etching method is not particularly limited, but may be used, for example, a method of immersing the chamfered portion in an etchant, spraying an etchant at a chamfered portion, or the like. Preferably, the etching is performed by immersing the window substrate in an etchant.

The etchant according to the present invention contains a fluorine-containing compound. The etchant including the fluorine-containing compound is a main component for etching the window substrate, and the etching agent is not particularly limited as long as it can be dissociated in water to generate fluorine ions, but preferably contains HF, NaF, KF, NH selected from Any of ₄ F, KBF ₄ , NH ₄ BF ₄ or NaBF ₄ , and more preferably HF.

The content of the fluorine-containing compound is 4 to 12 wt.% with respect to the total weight of the etching agent. Within this range, the content may be 4 to 12 wt.%, 4 to 10 wt.%, 4 to 8 wt.%, 4 to 10 wt.%, 4 to 8 wt.%, 5 to 12 wt.%. 5 to 9 wt.%, etc., preferably 4 to 10 wt.%, and more preferably 5 to 9 wt.%. If the content of the fluorine-containing compound is less than 4 wt.%, the embossing pattern of the present invention having the embossing within the specific size and ratio described above may not be obtained, and when the content exceeds 12 wt.%, the embossing pattern may not be obtained. And it may reduce the processability efficiency of processing costs, resulting in environmental pollution.

If desired, in addition to the fluorine-containing compound, the etchant according to the present invention may comprise at least one selected from the group consisting of sulfuric acid and nitric acid to enhance the erosion performance.

In addition to the above compounds, the etchant may further include an additive such as an surfactant or the like, and water as a remaining liquid as needed.

The temperature of the etchant is not particularly limited, and may be appropriately selected. For example, its temperature can be from 15 to 40 °C. Within this range, the temperature may be, for example, 15 to 40 ° C, 15 to 32 ° C, 15 to 30 ° C, 18 to 40 ° C, 18 to 32 ° C, 18 to 30 ° C, 20 to 40 ° C, 20 to 32 ° C. 20 to 30 ° C, etc., preferably 18 to 35 ° C, and more preferably 20 to 30 ° C. When the temperature of the etchant falls within the range of 15 to 40 ° C, the excellent stability of the etchant can be utilized to effectively form the embossed pattern of the invention.

The erosion step is performed for 20 seconds to 10 minutes. Within this range, the etching time may be, for example, 20 seconds to 10 minutes, 20 seconds to 8 minutes, 20 seconds to 5 minutes, 1 minute to 10 minutes, 1 minute to 8 minutes, 1 minute to 5 minutes, 1 minute to 3 minutes, 3 minutes to 8 minutes, 3 minutes to 5 minutes, and the like, preferably 1 minute to 8 minutes, and more preferably 1 minute to 5 minutes. If the erosion in the etching step is carried out for less than 20 seconds, the embossed pattern according to the present invention may not be obtained, and the pattern of the chamfered portion of the non-window substrate may be damaged.

The window substrate used in the present invention may be prepared of any material, and the material is not particularly limited as long as it has high durability to sufficiently protect the touch panel and the like from external force, and allows the user to satisfactorily view the display. And any window substrate used in the art can be employed without particular limitation. For example, glass, polyether oxime (PES), polyacrylate (PAR), polyether phthalimide (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET) can be used. ), polysulfurized benzene (PPS), polyarylate, polyamidamine, polycarbonate (PC), cellulose triacetate (TAC), cellulose acetate propionate (CAP), or the like. It is preferred to use glass, and more preferably to use tempered glass.

The object to which the window substrate according to the present invention is applied is not particularly limited, but can be used as a transparent protective window such as a monitor, a television, or the like, or can be applied to a touch panel or the like.

When the window substrate of the present invention is applied to a touch screen panel, a panel having a laminated structure including an electrode pattern formed on one surface thereof before the chamfering process can be used.

Depending on the particular use of the touch screen panel, such a laminate structure can be any conventional laminate structure as is known in the art without particular limitations. For example, at least one of an electrode pattern, an insulating layer, a BM, an index matching layer (transparent dielectric layer), a protective layer, a diffusion preventing film, and the like may be used to prepare structures stacked in various orders, but Not limited to this.

The electrode pattern can function to detect static electricity generated from the human body (when his or her finger touches the display portion of the touch area of the image sensor) and then converts it into an electrical signal.

The conductive material used to form the electrode pattern is not particularly limited, but may include, for example, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZO). , cadmium tin oxide (CTO), poly(3,4-ethylenedioxythiophene) (PEDOT), carbon nanotubes (CNT), metal wires, etc., they can Used alone or in combination of two or more.

The metal used for the metal wire is not particularly limited, but may include, for example, silver (Ag), gold, aluminum, copper, iron, nickel, titanium, tantalum, chromium, or the like, which may be used alone or in two or more kinds. Used in combination.

The electrode pattern circuit may be formed on a region corresponding to the non-display portion of the electrode pattern. The electrode pattern circuit functions to deliver an electrical signal generated from the electrode pattern to the FPCB, the IC wafer, or the like through the touch of the display portion formed on the window substrate. The electrode pattern circuit can be formed using the same materials and methods as those used to form the electrode pattern.

The insulating layer functions to prevent electrical shorting of the electrodes, and the material thereof is not particularly limited. For example, the insulating layer may be formed of a metal oxide, a cerium oxide, a polymer, an acrylic resin, or the like.

In order to conceal and shield the inner panel and the wire, a BM (non-conductive pattern) is formed on the non-display portion (which is an edge portion formed on the edge portion of the window substrate) so that the display portion of the touch region is Defined in the center portion of the window substrate.

The non-conductive pattern can be formed using a composition for forming a non-conductive pattern including a binder resin, a polymerizable compound, a polymerization initiator, a pigment, a solvent, and the like.

The composition for forming a non-conductive pattern may further comprise a non-conductive metal, a non-conductive oxide, or a mixture thereof.

The non-conductive metal is not particularly limited, but may include, for example, tin or an aluminum-bismuth alloy.

The non-conductive oxide is not particularly limited but may contain, for example, titanium oxide, cerium oxide or a mixture thereof.

The index matching layer is usually formed of cerium oxide, cerium oxide or a mixture thereof.

The protective layer serves to prevent the laminated structure including the electrode pattern from being contaminated or damaged from the outside.

The scattering prevention film serves to protect the above individual patterns and to prevent the above-mentioned individual patterns from collapsing when the window substrate is broken.

The material for preventing the scattering film is not particularly limited as long as it is transparent and provides durability, and may include, for example, polyethylene terephthalate (PET).

The method of forming the diffusion preventing film is not particularly limited, but may include, for example, spin coating, roll coating, spray coating, dip coating, shower coating, blade dispensing, inkjet printing, screen printing, pad printing, gravure printing, lithography. , flexographic printing, stencil printing, embossing, and the like.

In the following, preferred embodiments will be described with reference to examples and comparative examples to more specifically understand the invention. However, those skilled in the art will understand that the specific embodiments are provided for the purpose of illustration, and are not intended to limit the scope of the invention as claimed. Therefore, it is apparent to those skilled in the art that various changes and modifications may be made within the scope and spirit of the invention, and are included within the scope of the appended claims. Sample example 1

The polishing process is performed by bringing the circular polishing wheel into contact with the cutting portion and moving the polishing wheel at a speed of 150 mm/sec to polish the cut portion, which is performed on the cut portion of the tempered glass, which has a thickness of 0.7 mm and The width of 60 cm, cut by Nd; YAG laser, the circular polishing wheel has a polishing plane and rotates at 20,000 rpm, and a cutting medium having a particle size of 700 mesh is spread on the polishing plane.

Next, the above-mentioned polished cut portion was etched at a temperature of 18 ° C with an etchant comprising 5 wt.% of HF to form an embossed pattern on the cut portion. Example 2

The chamfering procedure on the cut portion was carried out according to the same procedure as described in Example 1, except that the erosion of the erosion step was performed for 3 minutes. Comparative example 1

The chamfering procedure on the cut portion was performed according to the same procedure as described in Example 1, except that the erosion step was not performed. Experimental example: Measurement of elongation

The elongation was measured by placing two support spans separated from each other by a pitch of 20 mm in the opposite sides of the center of the window substrate subjected to the chamfering in Examples 1 and 2 and Comparative Example 1, and A load is applied to the upper portion of the window substrate by being placed over the upper span of the central upper portion of the substrate.

Next, the distance between the point of the upper span contact window substrate and the point at which the window substrate was broken (crosshead displacement) was measured to calculate the elongation according to the following formula 1, and the calculated results are shown in Table 1 below.

[Equation 1] Elongation (%) = (6Tδ) / s ² (where T represents the thickness of the window substrate (mm), δ represents the crosshead displacement (mm), and s represents the distance between the support spans (mm) ).

Fig. 1 illustrates a photograph of the chamfered portion in the example 1, and Fig. 2 illustrates a photograph of the chamfered portion in the comparative example 1.

[Table 1]

Referring to Table 1 above, it can be seen that the window substrate which is chamfered in Examples 1 and 2 respectively contains an embossed pattern in the chamfered portion, and the number of embossings having a long axis length of 5 mm or longer at the bottom is 85.8, respectively. % and 92.5%, they have a very good elongation of 0.8% and 1.2%, respectively.

Fig. 1 shows an SEM photograph of the chamfered portion of the window substrate which was chamfered in Example 1. Referring to Figure 1, it can be seen that the embossing pattern is clearly formed on the chamfered portion.

However, in Comparative Example 1 in which the etching step was not performed, the window substrate which was chamfered did not have an embossing pattern formed at the chamfered portion, and had a very poor elongation of 0.3%.

Fig. 2 shows an SEM photograph of the chamfered portion of the window substrate which was chamfered in Comparative Example 1. Referring to Fig. 2, it can be seen that no embossed pattern is formed on the chamfered portion.

no

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings in which: FIG. 1 is an SEM photograph showing the execution of the chamfering procedure according to the method of Example 1. The chamfered portion of the window substrate in which it is located; and FIG. 2 is an SEM photograph showing the chamfered portion of the window substrate on which the chamfering program is performed according to the method of Comparative Example 1.

Claims (8)

A window substrate comprising: an embossed pattern on a chamfered portion thereof, wherein the number of embossments at the bottom of one of the major axis lengths of 5 mm or longer relative to a total number of embossments 60% or more. The window substrate of claim 1, wherein the chamfered portion comprises an embossed pattern, wherein a total number of embossments has a bottom and the bottom has a major axis length of less than 5 mm The number of embossings is 2 to 40%, the number of embossments having a bottom and having a major axis length of 5 mm to 10 mm is 20 to 70%, having a bottom and the bottom having more than 10 The number of embossments of a long axis length of mm but not more than 20 mm is 10 to 40%, and the number of embossings having a bottom and a long axis length of the bottom having more than 20 mm is 0 to 20% . The window substrate of claim 1, wherein the window substrate is selected from the group consisting of glass, polyether enamel (PES), polyacrylate (PAR), polyether phthalimide (PEI), and polynaphthalene dicarboxylic acid. Ethylene diester (PEN), polyethylene terephthalate (PET), polysulfide (PPS), polyarylate, polyamine, polycarbonate (PC), cellulose triacetate (TAC) And at least one of a group consisting of cellulose acetate propionate (CAP). The window substrate of claim 3, wherein the glass is a tempered glass. A method for chamfering a window substrate, comprising: polishing a cut portion of the window substrate by contacting a rotating polishing wheel with the cutting portion, and one along the cutting portion at 100 to 800 mm/sec Moving the polishing wheel at a speed; and etching the polished cutting portion with an etchant, the etchant comprising a fluorine-containing compound at a content of 4 to 12 wt.% relative to a total weight of the etchant to An embossed pattern is formed on a chamfered portion of the window substrate according to any one of claims 1 to 4. The method of claim 5, wherein the polishing wheel has a polishing plane on which a cutting medium having a particle size of 200 to 1200 mesh is dispersed. The method of claim 5, wherein in the polishing step, the polishing wheel is rotated at a speed of 10,000 to 50,000 rpm. The method of claim 5, wherein the temperature of the etchant is 15 to 40 °C.