CN110088058B

CN110088058B - Glass plate and method for manufacturing glass plate

Info

Publication number: CN110088058B
Application number: CN201780077340.6A
Authority: CN
Inventors: 奥隼人; 粟津晃; 竹内久博; 太和田佑
Original assignee: Nippon Electric Glass Co Ltd
Current assignee: Nippon Electric Glass Co Ltd
Priority date: 2016-12-27
Filing date: 2017-11-30
Publication date: 2021-12-10
Anticipated expiration: 2037-11-30
Also published as: JP2018104238A; KR20190102208A; TW201831267A; WO2018123416A1; TWI735719B; JP6913295B2; KR102403487B1; CN110088058A

Abstract

The glass plate (1) of the present invention is in a state in which the end face (2) is subjected to a predetermined processing, and the arithmetic mean waviness (Wa) of the end face (2) of the glass plate (1) is 2.7 [ mu ] m or more.

Description

Glass plate and method for manufacturing glass plate

Technical Field

The present invention relates to a glass plate and a method for manufacturing the glass plate.

Background

In recent years, in order to meet a demand for improvement in production efficiency of liquid crystal displays and the like, there has been an increasing demand for improvement in production efficiency of glass substrates used for the displays and the like. In the production of a glass substrate, a large glass raw plate (forming raw plate) is processed to cut out one or more glass substrates. This enables obtaining a glass substrate having a desired size.

On the other hand, since the end surface of the glass substrate cut out from the glass original plate is generally a cut surface or a cut surface, minute flaws (defects) are often present. If a flaw is present on the end face of the glass substrate, a crack or the like is generated from the flaw, and therefore, in order to prevent this, grinding (rough polishing) and polishing (finish polishing) are performed on the end face of the glass substrate (see, for example, patent document 1).

Prior art documents

Patent document

Patent document 1: international publication No. WO2013/187400

Disclosure of Invention

Problems to be solved by the invention

However, in the production process of a liquid crystal display, there are various processes performed on a glass substrate, such as a film formation process, an exposure process, and an etching process. At this time, the glass substrate is positioned by, for example, bringing the positioning pins into contact with the end surfaces. However, the contact between the end face and the positioning pin may cause generation of glass frit from the end face, and the glass frit may adhere to the main surface (flat surface having the largest area) of the glass plate. Since adhesion of glass frit causes film formation failure or disconnection failure, it is necessary to avoid generation of such glass frit as much as possible.

When the end surface is subjected to grinding using a grindstone as described above, for example, the end surface after the grinding becomes flat. However, since the positioning pin is made of rubber or plastic having a hardness of about 60 degrees, when the positioning pin is elastically deformed, the end surface after processing becomes too flat, and the contact area between the positioning pin and the end surface increases. As a result, there is a problem that glass frit is easily generated.

In view of the above circumstances, an object of the present invention is to prevent glass powder from being generated from an end face of a glass plate as much as possible by forming a predetermined microwaviness on the end face.

Means for solving the problems

The above object is achieved by the glass plate of the present invention. That is, the glass sheet is in a state where the end face is subjected to a predetermined processing, and is characterized in that the arithmetic average waviness Wa of the end face is 2.7 μm or more.

As described above, in the present invention, attention is paid to the arithmetic average waviness Wa of the end face, and a minimum value to be satisfied by the value of the arithmetic average waviness Wa is defined. In the end face of this type, for example, when a positioning member such as a pin is brought into contact with the end face of a glass plate at the time of each manufacturing process of the glass plate or a product including the glass plate as an element and at the time of conveyance between the processes, the positioning member mainly comes into contact with a mountain portion having a minute waviness (described later in detail) of the end face, and therefore, a contact area with the positioning member can be reduced. This can suppress the generation of glass frit.

In the glass sheet of the present invention, the average height Wc of the end face may be 5.0 μm or more.

By defining the average height Wc of the end surface in this way, the height difference between the peak portion and the trough portion of the micro-waviness of the end surface is increased, and the positioning member and the trough portion of the micro-waviness are less likely to contact each other. This can further reduce the contact area with the positioning member, and can more effectively suppress the generation of glass frit.

In the glass sheet of the present invention, the average length Wsm of the end face may be 2000 μm or more.

By defining the average length Wsm of the end face in this way, the period of the microwaviness is increased. Therefore, the number of the minute-waviness mountain portions in contact with the positioning member is reduced, and therefore, the contact area with the positioning member can be further reduced, and the generation of glass frit can be more effectively suppressed.

In the glass sheet of the present invention, the degree of deviation Wsk of the end face may be greater than 0.

By defining the degree of inclination Wsk of the end face in this way, the shape of the microwaviness can be indirectly defined. That is, when the inclination Wsk takes a positive value, the peak portion of the microwaviness tends to be a sharp shape. Therefore, by setting the skew Wsk to 0 or more, the contact area between the positioning member and the peak portion of the end face having the minute waviness can be reduced. This can further reduce the contact area with the positioning member, and can more effectively suppress the generation of glass frit.

In the glass sheet of the present invention, the relationship of the following expression 1 may be satisfied where a [ mm ] represents one period of the microwaviness exhibited at the end face and B [ mm ] represents a height difference between the peak portion and the valley portion.

[ formula 1]

The above-described specification is made by focusing on the relationship between the shape of the microwaviness appearing on the end surface of the glass plate and the contact state of the positioning pin. That is, when the end face of the glass plate is machined by a grinding wheel capable of rotating around the axis, as shown in fig. 3, a microwaviness 3 having a longer period of unevenness than a roughness curve such as a surface roughness Ra may appear on the end face 2. The microwaviness 3 is often expressed in a magnitude (order) equivalent to, for example, a waviness curve of the arithmetic average waviness Wa, and the uneven shape (the shape of the mountain portions 4 and the valley portions 5) is formed in a substantially circular arc shape following the outer shape of the grindstone. Therefore, for example, when considering a state in which the positioning pin 6 having the radius r [ mm ] is in contact with the

adjacent peak portions

4 and 4 of the minute waviness 3 formed in a substantially circular arc shape, the positioning pin 6 does not contact the valley portion 5 of the minute waviness 3 as long as the relationship defined in the following expression 2 is satisfied. In formula 2, the variable B is a height difference [ mm ] between the peak 4 and the valley 5, and the variable C is a distance [ mm ] from a midpoint P2 between the contact points P1 and P1 of the positioning pin 6 and the peak 4 to a center point P3 of the positioning pin 6.

[ formula 2]

B+C＞r

Here, the relationship shown in equation 3 holds between the radius r of the positioning pin 6, the period a, and the distance C. The variable a in formula 3 is the distance [ mm ] between the

adjacent ridges

4, 4 of the microwaviness 3.

[ formula 3]

When equation 3 is modified, the distance C is expressed as a function of the radius r and the period A as in equation 4.

[ formula 4]

When formula 4 is taken to formula 2 for finishing, formula 5 is obtained.

[ formula 5]

Here, when a representative size of the outer diameter dimension (twice the radius r) of the positioning pin 6 is 400mm, for example, expression 1 is obtained.

In this way, by setting the microwaviness to an optimum shape in consideration of the specific contact form with the positioning pin, it is possible to prevent the positioning pin from coming into contact with the valley portion of the microwaviness as much as possible. Therefore, the generation of glass frit can be more effectively suppressed.

The above object is also achieved by a method for producing a glass plate of the present invention. That is, the manufacturing method includes an end face machining step of performing a predetermined machining on an end face by relatively moving a rotating machining tool along the end face while contacting the end face of the glass plate, and is characterized in that the predetermined machining by a grindstone is performed on the end face so that an arithmetic average waviness Wa of the end face becomes 2.7 μm or more.

In the present invention, the arithmetic average waviness Wa of the end surface is focused on, and predetermined machining by a rotating machining tool is performed on the end surface so that the value of the arithmetic average waviness Wa becomes a value to be satisfied. According to this method, similarly to the glass sheet of the present invention, when the positioning member such as a pin is brought into contact with the end face of the glass sheet at the time of each manufacturing process or at the time of inter-process conveyance of the glass sheet or a product made of the glass sheet as an element, the positioning member is mainly brought into contact with the peak portion having the minute waviness of the end face, and therefore, the contact area with the positioning member can be reduced. This can suppress the generation of glass frit.

Effects of the invention

As described above, according to the present invention, the glass frit can be prevented from being generated from the end surface as much as possible by forming the predetermined microwaviness on the end surface of the glass plate.

Drawings

Fig. 1 is a schematic plan view of an end surface processing apparatus for a glass plate according to an embodiment of the present invention.

Fig. 2 is a side view of an essential part of the stone rotating system shown in fig. 1.

Fig. 3 is a view for explaining a contact manner between the end surface of the glass plate and the positioning pin at the waviness curve level.

Fig. 4 is a view showing a contact manner of an end surface of a glass plate and a positioning pin in the order of a waviness curve in another mode.

FIG. 5 is a graph showing the manner in which the end face of the glass sheet of the present invention contacts the positioning pin on the order of the waviness curve.

Detailed Description

An embodiment of the present invention will be described below with reference to fig. 1 to 5. First, a schematic configuration of an end surface processing apparatus used in the manufacturing method of the present embodiment will be described with reference to fig. 1 and 2.

As shown in fig. 1 and 2, the end surface processing apparatus 10 is used for performing a predetermined processing on an end surface 2 of a glass plate 1, and mainly includes a motor 13 for driving and

rotating grindstones

11 and 12 as end surface processing portions, and a spindle 14. The spindle 14 is connected to the motor 13. In the present embodiment, the motor 13 and the spindle 14 have a common rotation axis Y. The spindle 14 may be coupled to the main shaft of the motor 13 via a belt or the like.

The end face machining apparatus 10 having such a configuration may be provided with a device for controlling the pressing force of the grindstones 11(12) as described in patent document 1. Alternatively, the end face machining apparatus 10 may be configured to fix the positions of the grinding stones 11(12) during machining. Alternatively, the end face machining device 10 other than these may be used.

As shown in fig. 2, the

grindstones

11 and 12 are attached to the spindle 14 via a grindstone attachment flange 20. Specifically, the grindstones 11(12) are provided with fitting holes 21, and the grindstone mounting flange 20 is provided with fitting projections 22. By fitting the fitting convex portion 22 of the flange 20 for mounting a grinding stone into the fitting hole 21 of the grinding stone 11(12), the grinding stone 11(12) is coupled to the flange 20 for mounting a grinding stone, and the grinding stone 11(12) is positioned with respect to the flange 20 for mounting a grinding stone, including centering.

Further, a fitting concave portion 23 is provided on the side of the stone mounting flange 20 opposite to the fitting convex portion 22. The fitting recess 23 is tapered, and can be fitted to the tip end 24 of the mandrel 14, which is also tapered. Therefore, for example, after a sub-assembly 25 of the grindstone 11(12) and the grindstone attachment flange 20, which will be described later, is prepared, the sub-assembly 25 is attached to the distal end portion 24 of the spindle 14, whereby the grindstones 11(12) are automatically centered and positioned with respect to the spindle 14.

In the present embodiment, in order to perform two types of processing on the end surface 2 of the glass plate 1 (here, grinding processing mainly for chamfering the end surface 2 and polishing processing mainly for making minute irregularities on the end surface 2 uniform), grinding

stones

11 and 12 corresponding to the two types of processing may be used. That is, the grain size of the abrasive grains in the second grinding wheel 12 for polishing is the same as or larger than the grain size of the abrasive grains in the first grinding wheel 11 for grinding. The grain size of the abrasive grains in the first grinding stone 11 for grinding can be, for example, #100 to #1000, and the grain size of the abrasive grains in the second grinding stone 12 for polishing can be, for example, #200 to # 2000. The

grindstones

11 and 12 have a diameter of, for example, 100 to 200 mm.

The glass plate 1 has a rectangular plate shape as shown in fig. 1, for example. The thickness of the glass plate 1 is preferably 0.05mm to 10mm, and more preferably 0.2mm to 0.7mm, for example. Of course, the glass plate 1 to which the present invention can be applied is not limited to the above-described manner. For example, the present invention can be applied to a glass plate having a shape other than a rectangle (for example, a polygon other than a rectangle) or a glass plate having a thickness dimension other than 0.05mm to 10 mm.

The main surface (front surface and back surface) of the glass 1 is preferably a forged surface, that is, a molded surface without being processed by a grindstone or the like and without having a grinding mark. The arithmetic average roughness Ra (JIS R1683: 2014) of the main surface of glass 1 is preferably 10nm or less, more preferably 2nm or less.

The glass sheet 1 is relatively movable in a predetermined feed direction X with respect to the

grindstones

11, 12. In fig. 1, the glass sheet 1 is shown as being moved in the feeding direction X and the

grindstones

11 and 12 are fixed, but it is needless to say that the glass sheet 1 may be fixed and the

grindstones

11 and 12 may be moved in the direction opposite to the feeding direction X. In this case, either one of the glass plate 1 and the

grindstones

11 and 12 may be moved and the other may be fixed, or both may be moved.

The rotation direction of the grinding

stones

11 and 12 is arbitrary, but it is preferable that the rotation direction of each of the grinding

stones

11 and 12 is determined so as to rotate in a direction opposite to the feeding direction X of the glass sheet 1, for example. As described with reference to fig. 1, the rotation direction of each of the grinding

stones

11 and 12 is preferably determined such that the upper grinding

stones

11 and 12 rotate counterclockwise and the lower grinding

stones

11 and 12 rotate clockwise.

Next, an example of a method for manufacturing a glass plate using the end surface processing apparatus 10 will be described.

That is, the manufacturing method of the present embodiment includes an end surface processing step of performing predetermined processing on the end surface 2 by bringing the rotating

grindstones

11, 12 into contact with the end surface 2 of the glass plate 1 and relatively moving the

grindstones

11, 12 along the end surface 2. The manufacturing method may further include a step of preparing the glass plate 1 (glass plate preparation step). In the step of preparing the glass sheet 1, a forming original sheet is obtained by a down-draw method such as an overflow down-draw method, a float method, or the like, and the glass sheet 1 is cut out from the forming original sheet. After the end face 2 is processed, the glass sheet 1 is inspected and packed as necessary. In the step of preparing the glass plate 1, it is preferable to use the overflow down-draw method from the viewpoint of setting the main surfaces (front and back surfaces) of the glass plate 1 to be forged surfaces and the arithmetic mean roughness Ra thereof to be 10nm or less.

The step of performing a predetermined process on the end face 2 of the glass plate 1 (end face processing step) includes: a sub-assembly preparation step S1 of preparing the sub-assembly preparation step S1 so that the

grindstones

11 and 12 and the sub-assembly 25 of the grinding stone mounting flange 20 are in a predetermined static vibration and dynamic balance; and an end face machining step S2 of performing the end face machining using the prepared sub-assembly 25 in the end face machining step S2. In the step of performing the predetermined processing on the end face 2 of the glass plate 1, the end face processing is performed so that the arithmetic average waviness Wa of the end face 2 after the end face processing becomes 2.7 μm or more.

(S1) sub-assembly preparation step

In this step, the sub-assembly 25 of the

grindstones

11 and 12 and the flange 20 for mounting the grindstone is prepared so that the dynamic balance becomes a predetermined value or more, for example, 60g · mm or more. The dynamic balance can be measured using a predetermined dynamic balance measuring device.

In this case, the dynamic balance of each of the

grindstones

11 and 12 and the grinding stone mounting flange 20 is not particularly limited. When the dynamic balance of the sub-assembly 25 is 60g · mm or more, the

grindstones

11 and 12 and the grinding stone mounting flange 20 showing an arbitrary dynamic balance can be used.

(S2) end surface working step

In this step, the sub-assembly 25 prepared in the preparation step S1 is attached to, for example, the spindle 14 (see fig. 2) of the end surface processing apparatus 10 shown in fig. 1, and the predetermined end surface processing (grinding and polishing) is performed on the end surface 2 of the glass plate 1.

Here, fig. 4 shows an example of a waviness curve of the end face 2 'of the glass sheet 1' obtained in the case where the sub-assembly 25 having a dynamic balance of 10g · mm is used, and fig. 5 shows an example of a waviness curve of the end face 2 of the glass sheet 1 obtained in the case where the sub-assembly 25 having a dynamic balance of 80g · mm is used. These glass plates 1, 1' are each in the form of a rectangle of 2250mm by 2500mm and have a thickness of 0.5 mm. The end face processing is performed on the end faces of the long sides of the glass plates 1 and 1' by using the end face processing apparatus 10 shown in fig. 1. In the end face machining, a pair of first grinding stones 11 for grinding and a pair of second grinding stones 12 for polishing are arranged. The dynamic balance between the

grindstones

11 and 12 and the sub-assembly 25 of the flange 20 for mounting the grindstones (the first grindstone 11 for grinding and the second grindstone 12 for polishing) is the same.

As shown in fig. 4, the waviness curve of the end surface 2 'obtained when the sub-assembly 25 having a dynamic balance of 10g · mm is used exhibits a minute waviness 3' in which the height difference between the peak portions 4 'and the valley portions 5' is very small. In this case, the arithmetic average waviness Wa of the end face 2' is 2.5. mu.m, the average height Wc is 5 μm, and the average length Wsm is 2500. mu.m.

On the other hand, the waviness curve of the end face 2 obtained when the sub-assembly 25 having a dynamic balance of 80g · mm is used exhibits a substantially circular-arc-shaped microwaviness 3 clearly reflecting the outer shape of the pseudo-grindstones 11(12), as shown in fig. 5. In this case, the arithmetic average waviness Wa of the end face 2 was 2.8. mu.m, the average height Wc was 10 μm, and the average length Wsm was 4000. mu.m. In addition, the skew Wsk of the end face 2 is greater than 0.

Therefore, considering the contact state between the end surfaces 2 and 2 ' and the positioning pin 6 having, for example, a perfect circle in cross section, for example, the micro-waviness 3 ' shown in fig. 4 has a high probability of contacting the positioning pin 6 at the valley portions 5 ', whereas the micro-waviness 3 shown in fig. 5, that is, the micro-waviness 3 of the present invention, has a high probability of contacting the positioning pin 6 at the peak portions 4.

In this case, it is desirable that the parameters (the period a, the height difference B between the peak portion 4 and the valley portion 5) indicating the shape and the size of the microwaviness 3 satisfy the relationship of the above expression 1 from the viewpoint of minimizing the contact area with the positioning pin 6.

When the arithmetic average waviness Wa of the end face 2 is 2.7 μm or more, it is desirable that the average height Wc of the end face 2 is 5.0 μm or more, the average length Wsm is 2000 μm or more, and the skewness Wsk is a value exceeding 0.

As described above, in the present invention, the arithmetic average waviness Wa of the end surface 2 is focused, and predetermined end surface processing (grinding processing, polishing processing) by the rotational contact of the

grindstones

11, 12 is performed on the end surface 2 of the glass plate 1 so that the value of the arithmetic average waviness Wa becomes 2.7 μm or more. In the end face 2 of this type, for example, when a positioning member such as a positioning pin 6 is brought into contact with the end face 2 of the glass plate 1 at the time of each manufacturing process of the glass plate 1 or a product (such as a liquid crystal display) including the glass plate 1 as a factor and at the time of conveyance between processes, the end face 2 is mainly brought into contact with the mountain portion 4 of the microwaviness 3 of the end face 2. Therefore, the contact area between the end surface 2 of the glass plate 1 and the positioning member can be reduced, and generation of glass frit can be suppressed.

In consideration of the specific contact form with the positioning pin 6, the minute waviness 3 of the end surface 2 is formed in a shape satisfying the relationship of expression 1, whereby the positioning pin 6 can be prevented from contacting the trough portions 5 of the minute waviness 3 as much as possible. Therefore, the generation of glass frit can be more effectively suppressed.

From the viewpoint of further reducing the contact area between the end face 2 of the glass plate 1 and the positioning member, the arithmetic average waviness Wa of the end face 2 is preferably 3.0 μm or more. From the same viewpoint, the average height Wc of the end face 2 is preferably 5.0 μm or more, and more preferably 15 μm or more. The average length Wsm of the end face 2 is preferably 2000 μm or more, and more preferably 2500 μm or more.

On the other hand, if the contact area between the end face 2 of the glass plate 1 and the positioning member is excessively reduced, an excessive stress is generated in the peak portion 4 of the microwaviness 3 of the end face 2, and the glass plate 1 may be damaged. Therefore, the arithmetic average waviness Wa of the end face 2 is preferably 4.0 μm or less. The average height Wc of the end face 2 is preferably 20 μm or less. The average length Wsm of the end face 2 is preferably 6000 μm or less.

In the present invention, the arithmetic average waviness Wa, average height Wc, and average length Wsm of the end face 2 are in accordance with JIS B0601: 2013. In the measurement of the arithmetic average waviness Wa, the average height Wc, and the average length Wsm, the end faces of the glass sheets were measured at ten places at equal intervals along one side of the glass sheets. The arithmetic mean waviness Wa is the average of the measurement results at ten sites, and the minimum of the measurement results at ten sites is used for the mean height Wc and the mean length Wsm.

In the present invention, the average length Wsm measured by the above-described method is used for one cycle a of the microwaviness, and the average height Wc measured by the above-described method is used for the height difference B between the peak portion and the valley portion.

While one embodiment of the present invention has been described above, the glass plate and the method for producing the same according to the present invention are not limited to this embodiment, and various embodiments can be adopted within the scope of the present invention.

For example, in the above-described embodiment, the end face machining shown in fig. 1 and 2 is performed by using the sub-assembly 25 of the grindstone 11(12) and the flange 20 for mounting a grindstone, the dynamic balance of which is not less than a predetermined value, for example, not less than 60g · mm, to obtain the glass plate 1 having the end face 2 with the arithmetic mean waviness Wa of not less than 2.7 μm, but the end face machining method of the present invention is not limited to this. For example, the glass plate 1 having the end face 2 with an arithmetic mean waviness Wa of 2.7 μm or more can be obtained by performing the above-described end face processing while applying predetermined vibration to the

grindstones

11 and 12 in a manner other than adjustment of dynamic balance. Alternatively, the above-described edge face processing may be performed in a state where predetermined vibration is applied to the glass plate 1, thereby obtaining the glass plate 1 having the arithmetic average waviness Wa of the edge face 2 of 2.7 μm or more.

In the above embodiment, the case where two sets of the grinding stones 11(12) are disposed at positions facing each other with the glass plate 1 interposed therebetween and two sets (two sets) of the grinding

stones

11 and 12 having different grain sizes are disposed side by side in the conveying direction is exemplified, but it is needless to say that other arrangement modes can be adopted. For example, two or three or more sets of the grinding stones 11 and the polishing stones 12 may be arranged. In addition, as for the end faces 2 after the end face machining, for example, one or more sets of the grinding stones 11(12) having one type of shape may be arranged as long as the required quality including the shape can be secured.

In the above description, the present invention has been described as being applied to the case where the predetermined end face machining is performed on the end face 2 by the rotational contact of the

grindstones

11 and 12, but the end face machining method of the present invention is not limited to this. Any end face machining method can be adopted as long as the end face 2 is machined by moving the rotating machining tool along the end face 2 while contacting the end face 2 of the glass plate 1.

Further, the glass plate of the present invention is not limited to the one formed by the above-described end surface processing method. The glass sheet of the present invention can be obtained by applying any end face processing method as long as the arithmetic average waviness Wa of the end face 2 is 2.7 μm or more.

Claims

1. A glass plate in which an end face is subjected to a predetermined processing,

the end face has an arithmetic average waviness (Wa) of 2.7 to 4.0 [ mu ] m.

2. Glass sheet according to claim 1,

the average height (Wc) of the end face is 5.0 μm or more.

3. Glass sheet according to claim 1 or 2,

the average length (Wsm) of the end face is 2000 [ mu ] m or more.

4. Glass sheet according to claim 1 or 2,

the end face skew (Wsk) is greater than 0.

5. Glass sheet according to claim 1 or 2,

when a period of the microwaviness appearing on the end surface is defined as A [ mm ] and a height difference between the peak portion and the valley portion is defined as B [ mm ], a relationship expressed by the following expression 1 is satisfied:

[ formula 1]

6. A method for manufacturing a glass plate, comprising an end face machining step of performing predetermined machining on an end face of a glass plate by relatively moving a rotating machining tool along the end face while contacting the end face,

in the end face machining step, the predetermined machining by a grinding stone as the machining tool is performed on the end face so that an arithmetic average waviness (Wa) of the end face becomes 2.7 μm or more and 4.0 μm or less.